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commit: 5937201b16fe180982c20df4fc8ec78f7e8886f0 |
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Author: Mike Pagano <mpagano <AT> gentoo <DOT> org> |
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AuthorDate: Tue Aug 2 18:18:55 2022 +0000 |
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Commit: Mike Pagano <mpagano <AT> gentoo <DOT> org> |
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CommitDate: Tue Aug 2 18:18:55 2022 +0000 |
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URL: https://gitweb.gentoo.org/proj/linux-patches.git/commit/?id=5937201b |
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|
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Add the BMQ(BitMap Queue) Scheduler. |
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|
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See: https://gitlab.com/alfredchen/projectc |
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|
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Signed-off-by: Mike Pagano <mpagano <AT> gentoo.org> |
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|
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0000_README | 8 + |
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5020_BMQ-and-PDS-io-scheduler-v5.19-r0.patch | 9956 ++++++++++++++++++++++++++ |
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5021_BMQ-and-PDS-gentoo-defaults.patch | 13 + |
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3 files changed, 9977 insertions(+) |
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|
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diff --git a/0000_README b/0000_README |
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index 639f7346..3d9202d9 100644 |
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--- a/0000_README |
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+++ b/0000_README |
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@@ -78,3 +78,11 @@ Desc: Add Gentoo Linux support config settings and defaults. |
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Patch: 5010_enable-cpu-optimizations-universal.patch |
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From: https://github.com/graysky2/kernel_compiler_patch |
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Desc: Kernel >= 5.15 patch enables gcc = v11.1+ optimizations for additional CPUs. |
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+ |
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+Patch: 5020_BMQ-and-PDS-io-scheduler-v5.19-r0.patch |
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+From: https://gitlab.com/alfredchen/linux-prjc |
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+Desc: BMQ(BitMap Queue) Scheduler. A new CPU scheduler developed from PDS(incld). Inspired by the scheduler in zircon. |
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+ |
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+Patch: 5021_BMQ-and-PDS-gentoo-defaults.patch |
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+From: https://gitweb.gentoo.org/proj/linux-patches.git/ |
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+Desc: Set defaults for BMQ. Add archs as people test, default to N |
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|
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diff --git a/5020_BMQ-and-PDS-io-scheduler-v5.19-r0.patch b/5020_BMQ-and-PDS-io-scheduler-v5.19-r0.patch |
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new file mode 100644 |
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index 00000000..610cfe83 |
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--- /dev/null |
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+++ b/5020_BMQ-and-PDS-io-scheduler-v5.19-r0.patch |
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@@ -0,0 +1,9956 @@ |
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+diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt |
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+index cc3ea8febc62..ab4c5a35b999 100644 |
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+--- a/Documentation/admin-guide/kernel-parameters.txt |
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++++ b/Documentation/admin-guide/kernel-parameters.txt |
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+@@ -5299,6 +5299,12 @@ |
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+ sa1100ir [NET] |
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+ See drivers/net/irda/sa1100_ir.c. |
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+ |
50 |
++ sched_timeslice= |
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++ [KNL] Time slice in ms for Project C BMQ/PDS scheduler. |
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++ Format: integer 2, 4 |
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++ Default: 4 |
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++ See Documentation/scheduler/sched-BMQ.txt |
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++ |
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+ sched_verbose [KNL] Enables verbose scheduler debug messages. |
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+ |
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+ schedstats= [KNL,X86] Enable or disable scheduled statistics. |
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+diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst |
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+index ddccd1077462..e24781970a3d 100644 |
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+--- a/Documentation/admin-guide/sysctl/kernel.rst |
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++++ b/Documentation/admin-guide/sysctl/kernel.rst |
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+@@ -1524,3 +1524,13 @@ is 10 seconds. |
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+ |
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+ The softlockup threshold is (``2 * watchdog_thresh``). Setting this |
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+ tunable to zero will disable lockup detection altogether. |
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++ |
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++yield_type: |
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++=========== |
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++ |
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++BMQ/PDS CPU scheduler only. This determines what type of yield calls |
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++to sched_yield will perform. |
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++ |
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++ 0 - No yield. |
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++ 1 - Deboost and requeue task. (default) |
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++ 2 - Set run queue skip task. |
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+diff --git a/Documentation/scheduler/sched-BMQ.txt b/Documentation/scheduler/sched-BMQ.txt |
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+new file mode 100644 |
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+index 000000000000..05c84eec0f31 |
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+--- /dev/null |
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++++ b/Documentation/scheduler/sched-BMQ.txt |
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+@@ -0,0 +1,110 @@ |
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++ BitMap queue CPU Scheduler |
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++ -------------------------- |
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++ |
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++CONTENT |
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++======== |
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++ |
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++ Background |
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++ Design |
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++ Overview |
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++ Task policy |
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++ Priority management |
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++ BitMap Queue |
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++ CPU Assignment and Migration |
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++ |
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++ |
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++Background |
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++========== |
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++ |
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++BitMap Queue CPU scheduler, referred to as BMQ from here on, is an evolution |
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++of previous Priority and Deadline based Skiplist multiple queue scheduler(PDS), |
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++and inspired by Zircon scheduler. The goal of it is to keep the scheduler code |
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++simple, while efficiency and scalable for interactive tasks, such as desktop, |
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++movie playback and gaming etc. |
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++ |
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++Design |
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++====== |
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++ |
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++Overview |
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++-------- |
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++ |
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++BMQ use per CPU run queue design, each CPU(logical) has it's own run queue, |
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++each CPU is responsible for scheduling the tasks that are putting into it's |
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++run queue. |
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++ |
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++The run queue is a set of priority queues. Note that these queues are fifo |
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++queue for non-rt tasks or priority queue for rt tasks in data structure. See |
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++BitMap Queue below for details. BMQ is optimized for non-rt tasks in the fact |
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++that most applications are non-rt tasks. No matter the queue is fifo or |
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++priority, In each queue is an ordered list of runnable tasks awaiting execution |
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++and the data structures are the same. When it is time for a new task to run, |
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++the scheduler simply looks the lowest numbered queueue that contains a task, |
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++and runs the first task from the head of that queue. And per CPU idle task is |
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++also in the run queue, so the scheduler can always find a task to run on from |
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++its run queue. |
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++ |
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++Each task will assigned the same timeslice(default 4ms) when it is picked to |
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++start running. Task will be reinserted at the end of the appropriate priority |
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++queue when it uses its whole timeslice. When the scheduler selects a new task |
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++from the priority queue it sets the CPU's preemption timer for the remainder of |
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++the previous timeslice. When that timer fires the scheduler will stop execution |
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++on that task, select another task and start over again. |
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++ |
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++If a task blocks waiting for a shared resource then it's taken out of its |
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++priority queue and is placed in a wait queue for the shared resource. When it |
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++is unblocked it will be reinserted in the appropriate priority queue of an |
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++eligible CPU. |
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++ |
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++Task policy |
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++----------- |
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++ |
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++BMQ supports DEADLINE, FIFO, RR, NORMAL, BATCH and IDLE task policy like the |
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++mainline CFS scheduler. But BMQ is heavy optimized for non-rt task, that's |
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++NORMAL/BATCH/IDLE policy tasks. Below is the implementation detail of each |
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++policy. |
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++ |
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++DEADLINE |
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++ It is squashed as priority 0 FIFO task. |
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++ |
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++FIFO/RR |
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++ All RT tasks share one single priority queue in BMQ run queue designed. The |
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++complexity of insert operation is O(n). BMQ is not designed for system runs |
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++with major rt policy tasks. |
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++ |
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++NORMAL/BATCH/IDLE |
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++ BATCH and IDLE tasks are treated as the same policy. They compete CPU with |
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++NORMAL policy tasks, but they just don't boost. To control the priority of |
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++NORMAL/BATCH/IDLE tasks, simply use nice level. |
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++ |
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++ISO |
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++ ISO policy is not supported in BMQ. Please use nice level -20 NORMAL policy |
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++task instead. |
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++ |
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++Priority management |
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++------------------- |
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++ |
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++RT tasks have priority from 0-99. For non-rt tasks, there are three different |
169 |
++factors used to determine the effective priority of a task. The effective |
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++priority being what is used to determine which queue it will be in. |
171 |
++ |
172 |
++The first factor is simply the task’s static priority. Which is assigned from |
173 |
++task's nice level, within [-20, 19] in userland's point of view and [0, 39] |
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++internally. |
175 |
++ |
176 |
++The second factor is the priority boost. This is a value bounded between |
177 |
++[-MAX_PRIORITY_ADJ, MAX_PRIORITY_ADJ] used to offset the base priority, it is |
178 |
++modified by the following cases: |
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++ |
180 |
++*When a thread has used up its entire timeslice, always deboost its boost by |
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++increasing by one. |
182 |
++*When a thread gives up cpu control(voluntary or non-voluntary) to reschedule, |
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++and its switch-in time(time after last switch and run) below the thredhold |
184 |
++based on its priority boost, will boost its boost by decreasing by one buti is |
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++capped at 0 (won’t go negative). |
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++ |
187 |
++The intent in this system is to ensure that interactive threads are serviced |
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++quickly. These are usually the threads that interact directly with the user |
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++and cause user-perceivable latency. These threads usually do little work and |
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++spend most of their time blocked awaiting another user event. So they get the |
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++priority boost from unblocking while background threads that do most of the |
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++processing receive the priority penalty for using their entire timeslice. |
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+diff --git a/fs/proc/base.c b/fs/proc/base.c |
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+index 8dfa36a99c74..46397c606e01 100644 |
195 |
+--- a/fs/proc/base.c |
196 |
++++ b/fs/proc/base.c |
197 |
+@@ -479,7 +479,7 @@ static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns, |
198 |
+ seq_puts(m, "0 0 0\n"); |
199 |
+ else |
200 |
+ seq_printf(m, "%llu %llu %lu\n", |
201 |
+- (unsigned long long)task->se.sum_exec_runtime, |
202 |
++ (unsigned long long)tsk_seruntime(task), |
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+ (unsigned long long)task->sched_info.run_delay, |
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+ task->sched_info.pcount); |
205 |
+ |
206 |
+diff --git a/include/asm-generic/resource.h b/include/asm-generic/resource.h |
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+index 8874f681b056..59eb72bf7d5f 100644 |
208 |
+--- a/include/asm-generic/resource.h |
209 |
++++ b/include/asm-generic/resource.h |
210 |
+@@ -23,7 +23,7 @@ |
211 |
+ [RLIMIT_LOCKS] = { RLIM_INFINITY, RLIM_INFINITY }, \ |
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+ [RLIMIT_SIGPENDING] = { 0, 0 }, \ |
213 |
+ [RLIMIT_MSGQUEUE] = { MQ_BYTES_MAX, MQ_BYTES_MAX }, \ |
214 |
+- [RLIMIT_NICE] = { 0, 0 }, \ |
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++ [RLIMIT_NICE] = { 30, 30 }, \ |
216 |
+ [RLIMIT_RTPRIO] = { 0, 0 }, \ |
217 |
+ [RLIMIT_RTTIME] = { RLIM_INFINITY, RLIM_INFINITY }, \ |
218 |
+ } |
219 |
+diff --git a/include/linux/sched.h b/include/linux/sched.h |
220 |
+index c46f3a63b758..7c65e6317d97 100644 |
221 |
+--- a/include/linux/sched.h |
222 |
++++ b/include/linux/sched.h |
223 |
+@@ -751,8 +751,14 @@ struct task_struct { |
224 |
+ unsigned int ptrace; |
225 |
+ |
226 |
+ #ifdef CONFIG_SMP |
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+- int on_cpu; |
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+ struct __call_single_node wake_entry; |
229 |
++#endif |
230 |
++#if defined(CONFIG_SMP) || defined(CONFIG_SCHED_ALT) |
231 |
++ int on_cpu; |
232 |
++#endif |
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++ |
234 |
++#ifdef CONFIG_SMP |
235 |
++#ifndef CONFIG_SCHED_ALT |
236 |
+ unsigned int wakee_flips; |
237 |
+ unsigned long wakee_flip_decay_ts; |
238 |
+ struct task_struct *last_wakee; |
239 |
+@@ -766,6 +772,7 @@ struct task_struct { |
240 |
+ */ |
241 |
+ int recent_used_cpu; |
242 |
+ int wake_cpu; |
243 |
++#endif /* !CONFIG_SCHED_ALT */ |
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+ #endif |
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+ int on_rq; |
246 |
+ |
247 |
+@@ -774,6 +781,20 @@ struct task_struct { |
248 |
+ int normal_prio; |
249 |
+ unsigned int rt_priority; |
250 |
+ |
251 |
++#ifdef CONFIG_SCHED_ALT |
252 |
++ u64 last_ran; |
253 |
++ s64 time_slice; |
254 |
++ int sq_idx; |
255 |
++ struct list_head sq_node; |
256 |
++#ifdef CONFIG_SCHED_BMQ |
257 |
++ int boost_prio; |
258 |
++#endif /* CONFIG_SCHED_BMQ */ |
259 |
++#ifdef CONFIG_SCHED_PDS |
260 |
++ u64 deadline; |
261 |
++#endif /* CONFIG_SCHED_PDS */ |
262 |
++ /* sched_clock time spent running */ |
263 |
++ u64 sched_time; |
264 |
++#else /* !CONFIG_SCHED_ALT */ |
265 |
+ struct sched_entity se; |
266 |
+ struct sched_rt_entity rt; |
267 |
+ struct sched_dl_entity dl; |
268 |
+@@ -784,6 +805,7 @@ struct task_struct { |
269 |
+ unsigned long core_cookie; |
270 |
+ unsigned int core_occupation; |
271 |
+ #endif |
272 |
++#endif /* !CONFIG_SCHED_ALT */ |
273 |
+ |
274 |
+ #ifdef CONFIG_CGROUP_SCHED |
275 |
+ struct task_group *sched_task_group; |
276 |
+@@ -1517,6 +1539,15 @@ struct task_struct { |
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+ */ |
278 |
+ }; |
279 |
+ |
280 |
++#ifdef CONFIG_SCHED_ALT |
281 |
++#define tsk_seruntime(t) ((t)->sched_time) |
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++/* replace the uncertian rt_timeout with 0UL */ |
283 |
++#define tsk_rttimeout(t) (0UL) |
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++#else /* CFS */ |
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++#define tsk_seruntime(t) ((t)->se.sum_exec_runtime) |
286 |
++#define tsk_rttimeout(t) ((t)->rt.timeout) |
287 |
++#endif /* !CONFIG_SCHED_ALT */ |
288 |
++ |
289 |
+ static inline struct pid *task_pid(struct task_struct *task) |
290 |
+ { |
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+ return task->thread_pid; |
292 |
+diff --git a/include/linux/sched/deadline.h b/include/linux/sched/deadline.h |
293 |
+index 7c83d4d5a971..fa30f98cb2be 100644 |
294 |
+--- a/include/linux/sched/deadline.h |
295 |
++++ b/include/linux/sched/deadline.h |
296 |
+@@ -1,5 +1,24 @@ |
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+ /* SPDX-License-Identifier: GPL-2.0 */ |
298 |
+ |
299 |
++#ifdef CONFIG_SCHED_ALT |
300 |
++ |
301 |
++static inline int dl_task(struct task_struct *p) |
302 |
++{ |
303 |
++ return 0; |
304 |
++} |
305 |
++ |
306 |
++#ifdef CONFIG_SCHED_BMQ |
307 |
++#define __tsk_deadline(p) (0UL) |
308 |
++#endif |
309 |
++ |
310 |
++#ifdef CONFIG_SCHED_PDS |
311 |
++#define __tsk_deadline(p) ((((u64) ((p)->prio))<<56) | (p)->deadline) |
312 |
++#endif |
313 |
++ |
314 |
++#else |
315 |
++ |
316 |
++#define __tsk_deadline(p) ((p)->dl.deadline) |
317 |
++ |
318 |
+ /* |
319 |
+ * SCHED_DEADLINE tasks has negative priorities, reflecting |
320 |
+ * the fact that any of them has higher prio than RT and |
321 |
+@@ -21,6 +40,7 @@ static inline int dl_task(struct task_struct *p) |
322 |
+ { |
323 |
+ return dl_prio(p->prio); |
324 |
+ } |
325 |
++#endif /* CONFIG_SCHED_ALT */ |
326 |
+ |
327 |
+ static inline bool dl_time_before(u64 a, u64 b) |
328 |
+ { |
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+diff --git a/include/linux/sched/prio.h b/include/linux/sched/prio.h |
330 |
+index ab83d85e1183..6af9ae681116 100644 |
331 |
+--- a/include/linux/sched/prio.h |
332 |
++++ b/include/linux/sched/prio.h |
333 |
+@@ -18,6 +18,32 @@ |
334 |
+ #define MAX_PRIO (MAX_RT_PRIO + NICE_WIDTH) |
335 |
+ #define DEFAULT_PRIO (MAX_RT_PRIO + NICE_WIDTH / 2) |
336 |
+ |
337 |
++#ifdef CONFIG_SCHED_ALT |
338 |
++ |
339 |
++/* Undefine MAX_PRIO and DEFAULT_PRIO */ |
340 |
++#undef MAX_PRIO |
341 |
++#undef DEFAULT_PRIO |
342 |
++ |
343 |
++/* +/- priority levels from the base priority */ |
344 |
++#ifdef CONFIG_SCHED_BMQ |
345 |
++#define MAX_PRIORITY_ADJ (7) |
346 |
++ |
347 |
++#define MIN_NORMAL_PRIO (MAX_RT_PRIO) |
348 |
++#define MAX_PRIO (MIN_NORMAL_PRIO + NICE_WIDTH) |
349 |
++#define DEFAULT_PRIO (MIN_NORMAL_PRIO + NICE_WIDTH / 2) |
350 |
++#endif |
351 |
++ |
352 |
++#ifdef CONFIG_SCHED_PDS |
353 |
++#define MAX_PRIORITY_ADJ (0) |
354 |
++ |
355 |
++#define MIN_NORMAL_PRIO (128) |
356 |
++#define NORMAL_PRIO_NUM (64) |
357 |
++#define MAX_PRIO (MIN_NORMAL_PRIO + NORMAL_PRIO_NUM) |
358 |
++#define DEFAULT_PRIO (MAX_PRIO - NICE_WIDTH / 2) |
359 |
++#endif |
360 |
++ |
361 |
++#endif /* CONFIG_SCHED_ALT */ |
362 |
++ |
363 |
+ /* |
364 |
+ * Convert user-nice values [ -20 ... 0 ... 19 ] |
365 |
+ * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], |
366 |
+diff --git a/include/linux/sched/rt.h b/include/linux/sched/rt.h |
367 |
+index e5af028c08b4..0a7565d0d3cf 100644 |
368 |
+--- a/include/linux/sched/rt.h |
369 |
++++ b/include/linux/sched/rt.h |
370 |
+@@ -24,8 +24,10 @@ static inline bool task_is_realtime(struct task_struct *tsk) |
371 |
+ |
372 |
+ if (policy == SCHED_FIFO || policy == SCHED_RR) |
373 |
+ return true; |
374 |
++#ifndef CONFIG_SCHED_ALT |
375 |
+ if (policy == SCHED_DEADLINE) |
376 |
+ return true; |
377 |
++#endif |
378 |
+ return false; |
379 |
+ } |
380 |
+ |
381 |
+diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h |
382 |
+index 56cffe42abbc..e020fc572b22 100644 |
383 |
+--- a/include/linux/sched/topology.h |
384 |
++++ b/include/linux/sched/topology.h |
385 |
+@@ -233,7 +233,8 @@ static inline bool cpus_share_cache(int this_cpu, int that_cpu) |
386 |
+ |
387 |
+ #endif /* !CONFIG_SMP */ |
388 |
+ |
389 |
+-#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) |
390 |
++#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) && \ |
391 |
++ !defined(CONFIG_SCHED_ALT) |
392 |
+ extern void rebuild_sched_domains_energy(void); |
393 |
+ #else |
394 |
+ static inline void rebuild_sched_domains_energy(void) |
395 |
+diff --git a/init/Kconfig b/init/Kconfig |
396 |
+index c7900e8975f1..d2b593e3807d 100644 |
397 |
+--- a/init/Kconfig |
398 |
++++ b/init/Kconfig |
399 |
+@@ -812,6 +812,7 @@ menu "Scheduler features" |
400 |
+ config UCLAMP_TASK |
401 |
+ bool "Enable utilization clamping for RT/FAIR tasks" |
402 |
+ depends on CPU_FREQ_GOV_SCHEDUTIL |
403 |
++ depends on !SCHED_ALT |
404 |
+ help |
405 |
+ This feature enables the scheduler to track the clamped utilization |
406 |
+ of each CPU based on RUNNABLE tasks scheduled on that CPU. |
407 |
+@@ -858,6 +859,35 @@ config UCLAMP_BUCKETS_COUNT |
408 |
+ |
409 |
+ If in doubt, use the default value. |
410 |
+ |
411 |
++menuconfig SCHED_ALT |
412 |
++ bool "Alternative CPU Schedulers" |
413 |
++ default y |
414 |
++ help |
415 |
++ This feature enable alternative CPU scheduler" |
416 |
++ |
417 |
++if SCHED_ALT |
418 |
++ |
419 |
++choice |
420 |
++ prompt "Alternative CPU Scheduler" |
421 |
++ default SCHED_BMQ |
422 |
++ |
423 |
++config SCHED_BMQ |
424 |
++ bool "BMQ CPU scheduler" |
425 |
++ help |
426 |
++ The BitMap Queue CPU scheduler for excellent interactivity and |
427 |
++ responsiveness on the desktop and solid scalability on normal |
428 |
++ hardware and commodity servers. |
429 |
++ |
430 |
++config SCHED_PDS |
431 |
++ bool "PDS CPU scheduler" |
432 |
++ help |
433 |
++ The Priority and Deadline based Skip list multiple queue CPU |
434 |
++ Scheduler. |
435 |
++ |
436 |
++endchoice |
437 |
++ |
438 |
++endif |
439 |
++ |
440 |
+ endmenu |
441 |
+ |
442 |
+ # |
443 |
+@@ -911,6 +941,7 @@ config NUMA_BALANCING |
444 |
+ depends on ARCH_SUPPORTS_NUMA_BALANCING |
445 |
+ depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY |
446 |
+ depends on SMP && NUMA && MIGRATION && !PREEMPT_RT |
447 |
++ depends on !SCHED_ALT |
448 |
+ help |
449 |
+ This option adds support for automatic NUMA aware memory/task placement. |
450 |
+ The mechanism is quite primitive and is based on migrating memory when |
451 |
+@@ -1003,6 +1034,7 @@ config FAIR_GROUP_SCHED |
452 |
+ depends on CGROUP_SCHED |
453 |
+ default CGROUP_SCHED |
454 |
+ |
455 |
++if !SCHED_ALT |
456 |
+ config CFS_BANDWIDTH |
457 |
+ bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED" |
458 |
+ depends on FAIR_GROUP_SCHED |
459 |
+@@ -1025,6 +1057,7 @@ config RT_GROUP_SCHED |
460 |
+ realtime bandwidth for them. |
461 |
+ See Documentation/scheduler/sched-rt-group.rst for more information. |
462 |
+ |
463 |
++endif #!SCHED_ALT |
464 |
+ endif #CGROUP_SCHED |
465 |
+ |
466 |
+ config UCLAMP_TASK_GROUP |
467 |
+@@ -1268,6 +1301,7 @@ config CHECKPOINT_RESTORE |
468 |
+ |
469 |
+ config SCHED_AUTOGROUP |
470 |
+ bool "Automatic process group scheduling" |
471 |
++ depends on !SCHED_ALT |
472 |
+ select CGROUPS |
473 |
+ select CGROUP_SCHED |
474 |
+ select FAIR_GROUP_SCHED |
475 |
+diff --git a/init/init_task.c b/init/init_task.c |
476 |
+index 73cc8f03511a..2d0bad762895 100644 |
477 |
+--- a/init/init_task.c |
478 |
++++ b/init/init_task.c |
479 |
+@@ -75,9 +75,15 @@ struct task_struct init_task |
480 |
+ .stack = init_stack, |
481 |
+ .usage = REFCOUNT_INIT(2), |
482 |
+ .flags = PF_KTHREAD, |
483 |
++#ifdef CONFIG_SCHED_ALT |
484 |
++ .prio = DEFAULT_PRIO + MAX_PRIORITY_ADJ, |
485 |
++ .static_prio = DEFAULT_PRIO, |
486 |
++ .normal_prio = DEFAULT_PRIO + MAX_PRIORITY_ADJ, |
487 |
++#else |
488 |
+ .prio = MAX_PRIO - 20, |
489 |
+ .static_prio = MAX_PRIO - 20, |
490 |
+ .normal_prio = MAX_PRIO - 20, |
491 |
++#endif |
492 |
+ .policy = SCHED_NORMAL, |
493 |
+ .cpus_ptr = &init_task.cpus_mask, |
494 |
+ .user_cpus_ptr = NULL, |
495 |
+@@ -88,6 +94,17 @@ struct task_struct init_task |
496 |
+ .restart_block = { |
497 |
+ .fn = do_no_restart_syscall, |
498 |
+ }, |
499 |
++#ifdef CONFIG_SCHED_ALT |
500 |
++ .sq_node = LIST_HEAD_INIT(init_task.sq_node), |
501 |
++#ifdef CONFIG_SCHED_BMQ |
502 |
++ .boost_prio = 0, |
503 |
++ .sq_idx = 15, |
504 |
++#endif |
505 |
++#ifdef CONFIG_SCHED_PDS |
506 |
++ .deadline = 0, |
507 |
++#endif |
508 |
++ .time_slice = HZ, |
509 |
++#else |
510 |
+ .se = { |
511 |
+ .group_node = LIST_HEAD_INIT(init_task.se.group_node), |
512 |
+ }, |
513 |
+@@ -95,6 +112,7 @@ struct task_struct init_task |
514 |
+ .run_list = LIST_HEAD_INIT(init_task.rt.run_list), |
515 |
+ .time_slice = RR_TIMESLICE, |
516 |
+ }, |
517 |
++#endif |
518 |
+ .tasks = LIST_HEAD_INIT(init_task.tasks), |
519 |
+ #ifdef CONFIG_SMP |
520 |
+ .pushable_tasks = PLIST_NODE_INIT(init_task.pushable_tasks, MAX_PRIO), |
521 |
+diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt |
522 |
+index c2f1fd95a821..41654679b1b2 100644 |
523 |
+--- a/kernel/Kconfig.preempt |
524 |
++++ b/kernel/Kconfig.preempt |
525 |
+@@ -117,7 +117,7 @@ config PREEMPT_DYNAMIC |
526 |
+ |
527 |
+ config SCHED_CORE |
528 |
+ bool "Core Scheduling for SMT" |
529 |
+- depends on SCHED_SMT |
530 |
++ depends on SCHED_SMT && !SCHED_ALT |
531 |
+ help |
532 |
+ This option permits Core Scheduling, a means of coordinated task |
533 |
+ selection across SMT siblings. When enabled -- see |
534 |
+diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c |
535 |
+index 71a418858a5e..7e3016873db1 100644 |
536 |
+--- a/kernel/cgroup/cpuset.c |
537 |
++++ b/kernel/cgroup/cpuset.c |
538 |
+@@ -704,7 +704,7 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial) |
539 |
+ return ret; |
540 |
+ } |
541 |
+ |
542 |
+-#ifdef CONFIG_SMP |
543 |
++#if defined(CONFIG_SMP) && !defined(CONFIG_SCHED_ALT) |
544 |
+ /* |
545 |
+ * Helper routine for generate_sched_domains(). |
546 |
+ * Do cpusets a, b have overlapping effective cpus_allowed masks? |
547 |
+@@ -1100,7 +1100,7 @@ static void rebuild_sched_domains_locked(void) |
548 |
+ /* Have scheduler rebuild the domains */ |
549 |
+ partition_and_rebuild_sched_domains(ndoms, doms, attr); |
550 |
+ } |
551 |
+-#else /* !CONFIG_SMP */ |
552 |
++#else /* !CONFIG_SMP || CONFIG_SCHED_ALT */ |
553 |
+ static void rebuild_sched_domains_locked(void) |
554 |
+ { |
555 |
+ } |
556 |
+diff --git a/kernel/delayacct.c b/kernel/delayacct.c |
557 |
+index 164ed9ef77a3..c974a84b056f 100644 |
558 |
+--- a/kernel/delayacct.c |
559 |
++++ b/kernel/delayacct.c |
560 |
+@@ -150,7 +150,7 @@ int delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) |
561 |
+ */ |
562 |
+ t1 = tsk->sched_info.pcount; |
563 |
+ t2 = tsk->sched_info.run_delay; |
564 |
+- t3 = tsk->se.sum_exec_runtime; |
565 |
++ t3 = tsk_seruntime(tsk); |
566 |
+ |
567 |
+ d->cpu_count += t1; |
568 |
+ |
569 |
+diff --git a/kernel/exit.c b/kernel/exit.c |
570 |
+index 64c938ce36fe..a353f7ef5392 100644 |
571 |
+--- a/kernel/exit.c |
572 |
++++ b/kernel/exit.c |
573 |
+@@ -124,7 +124,7 @@ static void __exit_signal(struct task_struct *tsk) |
574 |
+ sig->curr_target = next_thread(tsk); |
575 |
+ } |
576 |
+ |
577 |
+- add_device_randomness((const void*) &tsk->se.sum_exec_runtime, |
578 |
++ add_device_randomness((const void*) &tsk_seruntime(tsk), |
579 |
+ sizeof(unsigned long long)); |
580 |
+ |
581 |
+ /* |
582 |
+@@ -145,7 +145,7 @@ static void __exit_signal(struct task_struct *tsk) |
583 |
+ sig->inblock += task_io_get_inblock(tsk); |
584 |
+ sig->oublock += task_io_get_oublock(tsk); |
585 |
+ task_io_accounting_add(&sig->ioac, &tsk->ioac); |
586 |
+- sig->sum_sched_runtime += tsk->se.sum_exec_runtime; |
587 |
++ sig->sum_sched_runtime += tsk_seruntime(tsk); |
588 |
+ sig->nr_threads--; |
589 |
+ __unhash_process(tsk, group_dead); |
590 |
+ write_sequnlock(&sig->stats_lock); |
591 |
+diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c |
592 |
+index 7779ee8abc2a..5b9893cdfb1b 100644 |
593 |
+--- a/kernel/locking/rtmutex.c |
594 |
++++ b/kernel/locking/rtmutex.c |
595 |
+@@ -300,21 +300,25 @@ static __always_inline void |
596 |
+ waiter_update_prio(struct rt_mutex_waiter *waiter, struct task_struct *task) |
597 |
+ { |
598 |
+ waiter->prio = __waiter_prio(task); |
599 |
+- waiter->deadline = task->dl.deadline; |
600 |
++ waiter->deadline = __tsk_deadline(task); |
601 |
+ } |
602 |
+ |
603 |
+ /* |
604 |
+ * Only use with rt_mutex_waiter_{less,equal}() |
605 |
+ */ |
606 |
+ #define task_to_waiter(p) \ |
607 |
+- &(struct rt_mutex_waiter){ .prio = __waiter_prio(p), .deadline = (p)->dl.deadline } |
608 |
++ &(struct rt_mutex_waiter){ .prio = __waiter_prio(p), .deadline = __tsk_deadline(p) } |
609 |
+ |
610 |
+ static __always_inline int rt_mutex_waiter_less(struct rt_mutex_waiter *left, |
611 |
+ struct rt_mutex_waiter *right) |
612 |
+ { |
613 |
++#ifdef CONFIG_SCHED_PDS |
614 |
++ return (left->deadline < right->deadline); |
615 |
++#else |
616 |
+ if (left->prio < right->prio) |
617 |
+ return 1; |
618 |
+ |
619 |
++#ifndef CONFIG_SCHED_BMQ |
620 |
+ /* |
621 |
+ * If both waiters have dl_prio(), we check the deadlines of the |
622 |
+ * associated tasks. |
623 |
+@@ -323,16 +327,22 @@ static __always_inline int rt_mutex_waiter_less(struct rt_mutex_waiter *left, |
624 |
+ */ |
625 |
+ if (dl_prio(left->prio)) |
626 |
+ return dl_time_before(left->deadline, right->deadline); |
627 |
++#endif |
628 |
+ |
629 |
+ return 0; |
630 |
++#endif |
631 |
+ } |
632 |
+ |
633 |
+ static __always_inline int rt_mutex_waiter_equal(struct rt_mutex_waiter *left, |
634 |
+ struct rt_mutex_waiter *right) |
635 |
+ { |
636 |
++#ifdef CONFIG_SCHED_PDS |
637 |
++ return (left->deadline == right->deadline); |
638 |
++#else |
639 |
+ if (left->prio != right->prio) |
640 |
+ return 0; |
641 |
+ |
642 |
++#ifndef CONFIG_SCHED_BMQ |
643 |
+ /* |
644 |
+ * If both waiters have dl_prio(), we check the deadlines of the |
645 |
+ * associated tasks. |
646 |
+@@ -341,8 +351,10 @@ static __always_inline int rt_mutex_waiter_equal(struct rt_mutex_waiter *left, |
647 |
+ */ |
648 |
+ if (dl_prio(left->prio)) |
649 |
+ return left->deadline == right->deadline; |
650 |
++#endif |
651 |
+ |
652 |
+ return 1; |
653 |
++#endif |
654 |
+ } |
655 |
+ |
656 |
+ static inline bool rt_mutex_steal(struct rt_mutex_waiter *waiter, |
657 |
+diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile |
658 |
+index 976092b7bd45..31d587c16ec1 100644 |
659 |
+--- a/kernel/sched/Makefile |
660 |
++++ b/kernel/sched/Makefile |
661 |
+@@ -28,7 +28,12 @@ endif |
662 |
+ # These compilation units have roughly the same size and complexity - so their |
663 |
+ # build parallelizes well and finishes roughly at once: |
664 |
+ # |
665 |
++ifdef CONFIG_SCHED_ALT |
666 |
++obj-y += alt_core.o |
667 |
++obj-$(CONFIG_SCHED_DEBUG) += alt_debug.o |
668 |
++else |
669 |
+ obj-y += core.o |
670 |
+ obj-y += fair.o |
671 |
++endif |
672 |
+ obj-y += build_policy.o |
673 |
+ obj-y += build_utility.o |
674 |
+diff --git a/kernel/sched/alt_core.c b/kernel/sched/alt_core.c |
675 |
+new file mode 100644 |
676 |
+index 000000000000..d0ab41c4d9ad |
677 |
+--- /dev/null |
678 |
++++ b/kernel/sched/alt_core.c |
679 |
+@@ -0,0 +1,7807 @@ |
680 |
++/* |
681 |
++ * kernel/sched/alt_core.c |
682 |
++ * |
683 |
++ * Core alternative kernel scheduler code and related syscalls |
684 |
++ * |
685 |
++ * Copyright (C) 1991-2002 Linus Torvalds |
686 |
++ * |
687 |
++ * 2009-08-13 Brainfuck deadline scheduling policy by Con Kolivas deletes |
688 |
++ * a whole lot of those previous things. |
689 |
++ * 2017-09-06 Priority and Deadline based Skip list multiple queue kernel |
690 |
++ * scheduler by Alfred Chen. |
691 |
++ * 2019-02-20 BMQ(BitMap Queue) kernel scheduler by Alfred Chen. |
692 |
++ */ |
693 |
++#include <linux/sched/cputime.h> |
694 |
++#include <linux/sched/debug.h> |
695 |
++#include <linux/sched/isolation.h> |
696 |
++#include <linux/sched/loadavg.h> |
697 |
++#include <linux/sched/mm.h> |
698 |
++#include <linux/sched/nohz.h> |
699 |
++#include <linux/sched/stat.h> |
700 |
++#include <linux/sched/wake_q.h> |
701 |
++ |
702 |
++#include <linux/blkdev.h> |
703 |
++#include <linux/context_tracking.h> |
704 |
++#include <linux/cpuset.h> |
705 |
++#include <linux/delayacct.h> |
706 |
++#include <linux/init_task.h> |
707 |
++#include <linux/kcov.h> |
708 |
++#include <linux/kprobes.h> |
709 |
++#include <linux/profile.h> |
710 |
++#include <linux/nmi.h> |
711 |
++#include <linux/scs.h> |
712 |
++ |
713 |
++#include <uapi/linux/sched/types.h> |
714 |
++ |
715 |
++#include <asm/switch_to.h> |
716 |
++ |
717 |
++#define CREATE_TRACE_POINTS |
718 |
++#include <trace/events/sched.h> |
719 |
++#undef CREATE_TRACE_POINTS |
720 |
++ |
721 |
++#include "sched.h" |
722 |
++ |
723 |
++#include "pelt.h" |
724 |
++ |
725 |
++#include "../../fs/io-wq.h" |
726 |
++#include "../smpboot.h" |
727 |
++ |
728 |
++/* |
729 |
++ * Export tracepoints that act as a bare tracehook (ie: have no trace event |
730 |
++ * associated with them) to allow external modules to probe them. |
731 |
++ */ |
732 |
++EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_irq_tp); |
733 |
++ |
734 |
++#ifdef CONFIG_SCHED_DEBUG |
735 |
++#define sched_feat(x) (1) |
736 |
++/* |
737 |
++ * Print a warning if need_resched is set for the given duration (if |
738 |
++ * LATENCY_WARN is enabled). |
739 |
++ * |
740 |
++ * If sysctl_resched_latency_warn_once is set, only one warning will be shown |
741 |
++ * per boot. |
742 |
++ */ |
743 |
++__read_mostly int sysctl_resched_latency_warn_ms = 100; |
744 |
++__read_mostly int sysctl_resched_latency_warn_once = 1; |
745 |
++#else |
746 |
++#define sched_feat(x) (0) |
747 |
++#endif /* CONFIG_SCHED_DEBUG */ |
748 |
++ |
749 |
++#define ALT_SCHED_VERSION "v5.19-r0" |
750 |
++ |
751 |
++/* rt_prio(prio) defined in include/linux/sched/rt.h */ |
752 |
++#define rt_task(p) rt_prio((p)->prio) |
753 |
++#define rt_policy(policy) ((policy) == SCHED_FIFO || (policy) == SCHED_RR) |
754 |
++#define task_has_rt_policy(p) (rt_policy((p)->policy)) |
755 |
++ |
756 |
++#define STOP_PRIO (MAX_RT_PRIO - 1) |
757 |
++ |
758 |
++/* Default time slice is 4 in ms, can be set via kernel parameter "sched_timeslice" */ |
759 |
++u64 sched_timeslice_ns __read_mostly = (4 << 20); |
760 |
++ |
761 |
++static inline void requeue_task(struct task_struct *p, struct rq *rq, int idx); |
762 |
++ |
763 |
++#ifdef CONFIG_SCHED_BMQ |
764 |
++#include "bmq.h" |
765 |
++#endif |
766 |
++#ifdef CONFIG_SCHED_PDS |
767 |
++#include "pds.h" |
768 |
++#endif |
769 |
++ |
770 |
++static int __init sched_timeslice(char *str) |
771 |
++{ |
772 |
++ int timeslice_ms; |
773 |
++ |
774 |
++ get_option(&str, ×lice_ms); |
775 |
++ if (2 != timeslice_ms) |
776 |
++ timeslice_ms = 4; |
777 |
++ sched_timeslice_ns = timeslice_ms << 20; |
778 |
++ sched_timeslice_imp(timeslice_ms); |
779 |
++ |
780 |
++ return 0; |
781 |
++} |
782 |
++early_param("sched_timeslice", sched_timeslice); |
783 |
++ |
784 |
++/* Reschedule if less than this many μs left */ |
785 |
++#define RESCHED_NS (100 << 10) |
786 |
++ |
787 |
++/** |
788 |
++ * sched_yield_type - Choose what sort of yield sched_yield will perform. |
789 |
++ * 0: No yield. |
790 |
++ * 1: Deboost and requeue task. (default) |
791 |
++ * 2: Set rq skip task. |
792 |
++ */ |
793 |
++int sched_yield_type __read_mostly = 1; |
794 |
++ |
795 |
++#ifdef CONFIG_SMP |
796 |
++static cpumask_t sched_rq_pending_mask ____cacheline_aligned_in_smp; |
797 |
++ |
798 |
++DEFINE_PER_CPU(cpumask_t [NR_CPU_AFFINITY_LEVELS], sched_cpu_topo_masks); |
799 |
++DEFINE_PER_CPU(cpumask_t *, sched_cpu_llc_mask); |
800 |
++DEFINE_PER_CPU(cpumask_t *, sched_cpu_topo_end_mask); |
801 |
++ |
802 |
++#ifdef CONFIG_SCHED_SMT |
803 |
++DEFINE_STATIC_KEY_FALSE(sched_smt_present); |
804 |
++EXPORT_SYMBOL_GPL(sched_smt_present); |
805 |
++#endif |
806 |
++ |
807 |
++/* |
808 |
++ * Keep a unique ID per domain (we use the first CPUs number in the cpumask of |
809 |
++ * the domain), this allows us to quickly tell if two cpus are in the same cache |
810 |
++ * domain, see cpus_share_cache(). |
811 |
++ */ |
812 |
++DEFINE_PER_CPU(int, sd_llc_id); |
813 |
++#endif /* CONFIG_SMP */ |
814 |
++ |
815 |
++static DEFINE_MUTEX(sched_hotcpu_mutex); |
816 |
++ |
817 |
++DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); |
818 |
++ |
819 |
++#ifndef prepare_arch_switch |
820 |
++# define prepare_arch_switch(next) do { } while (0) |
821 |
++#endif |
822 |
++#ifndef finish_arch_post_lock_switch |
823 |
++# define finish_arch_post_lock_switch() do { } while (0) |
824 |
++#endif |
825 |
++ |
826 |
++#ifdef CONFIG_SCHED_SMT |
827 |
++static cpumask_t sched_sg_idle_mask ____cacheline_aligned_in_smp; |
828 |
++#endif |
829 |
++static cpumask_t sched_rq_watermark[SCHED_QUEUE_BITS] ____cacheline_aligned_in_smp; |
830 |
++ |
831 |
++/* sched_queue related functions */ |
832 |
++static inline void sched_queue_init(struct sched_queue *q) |
833 |
++{ |
834 |
++ int i; |
835 |
++ |
836 |
++ bitmap_zero(q->bitmap, SCHED_QUEUE_BITS); |
837 |
++ for(i = 0; i < SCHED_BITS; i++) |
838 |
++ INIT_LIST_HEAD(&q->heads[i]); |
839 |
++} |
840 |
++ |
841 |
++/* |
842 |
++ * Init idle task and put into queue structure of rq |
843 |
++ * IMPORTANT: may be called multiple times for a single cpu |
844 |
++ */ |
845 |
++static inline void sched_queue_init_idle(struct sched_queue *q, |
846 |
++ struct task_struct *idle) |
847 |
++{ |
848 |
++ idle->sq_idx = IDLE_TASK_SCHED_PRIO; |
849 |
++ INIT_LIST_HEAD(&q->heads[idle->sq_idx]); |
850 |
++ list_add(&idle->sq_node, &q->heads[idle->sq_idx]); |
851 |
++} |
852 |
++ |
853 |
++/* water mark related functions */ |
854 |
++static inline void update_sched_rq_watermark(struct rq *rq) |
855 |
++{ |
856 |
++ unsigned long watermark = find_first_bit(rq->queue.bitmap, SCHED_QUEUE_BITS); |
857 |
++ unsigned long last_wm = rq->watermark; |
858 |
++ unsigned long i; |
859 |
++ int cpu; |
860 |
++ |
861 |
++ if (watermark == last_wm) |
862 |
++ return; |
863 |
++ |
864 |
++ rq->watermark = watermark; |
865 |
++ cpu = cpu_of(rq); |
866 |
++ if (watermark < last_wm) { |
867 |
++ for (i = last_wm; i > watermark; i--) |
868 |
++ cpumask_clear_cpu(cpu, sched_rq_watermark + SCHED_QUEUE_BITS - i); |
869 |
++#ifdef CONFIG_SCHED_SMT |
870 |
++ if (static_branch_likely(&sched_smt_present) && |
871 |
++ IDLE_TASK_SCHED_PRIO == last_wm) |
872 |
++ cpumask_andnot(&sched_sg_idle_mask, |
873 |
++ &sched_sg_idle_mask, cpu_smt_mask(cpu)); |
874 |
++#endif |
875 |
++ return; |
876 |
++ } |
877 |
++ /* last_wm < watermark */ |
878 |
++ for (i = watermark; i > last_wm; i--) |
879 |
++ cpumask_set_cpu(cpu, sched_rq_watermark + SCHED_QUEUE_BITS - i); |
880 |
++#ifdef CONFIG_SCHED_SMT |
881 |
++ if (static_branch_likely(&sched_smt_present) && |
882 |
++ IDLE_TASK_SCHED_PRIO == watermark) { |
883 |
++ cpumask_t tmp; |
884 |
++ |
885 |
++ cpumask_and(&tmp, cpu_smt_mask(cpu), sched_rq_watermark); |
886 |
++ if (cpumask_equal(&tmp, cpu_smt_mask(cpu))) |
887 |
++ cpumask_or(&sched_sg_idle_mask, |
888 |
++ &sched_sg_idle_mask, cpu_smt_mask(cpu)); |
889 |
++ } |
890 |
++#endif |
891 |
++} |
892 |
++ |
893 |
++/* |
894 |
++ * This routine assume that the idle task always in queue |
895 |
++ */ |
896 |
++static inline struct task_struct *sched_rq_first_task(struct rq *rq) |
897 |
++{ |
898 |
++ unsigned long idx = find_first_bit(rq->queue.bitmap, SCHED_QUEUE_BITS); |
899 |
++ const struct list_head *head = &rq->queue.heads[sched_prio2idx(idx, rq)]; |
900 |
++ |
901 |
++ return list_first_entry(head, struct task_struct, sq_node); |
902 |
++} |
903 |
++ |
904 |
++static inline struct task_struct * |
905 |
++sched_rq_next_task(struct task_struct *p, struct rq *rq) |
906 |
++{ |
907 |
++ unsigned long idx = p->sq_idx; |
908 |
++ struct list_head *head = &rq->queue.heads[idx]; |
909 |
++ |
910 |
++ if (list_is_last(&p->sq_node, head)) { |
911 |
++ idx = find_next_bit(rq->queue.bitmap, SCHED_QUEUE_BITS, |
912 |
++ sched_idx2prio(idx, rq) + 1); |
913 |
++ head = &rq->queue.heads[sched_prio2idx(idx, rq)]; |
914 |
++ |
915 |
++ return list_first_entry(head, struct task_struct, sq_node); |
916 |
++ } |
917 |
++ |
918 |
++ return list_next_entry(p, sq_node); |
919 |
++} |
920 |
++ |
921 |
++static inline struct task_struct *rq_runnable_task(struct rq *rq) |
922 |
++{ |
923 |
++ struct task_struct *next = sched_rq_first_task(rq); |
924 |
++ |
925 |
++ if (unlikely(next == rq->skip)) |
926 |
++ next = sched_rq_next_task(next, rq); |
927 |
++ |
928 |
++ return next; |
929 |
++} |
930 |
++ |
931 |
++/* |
932 |
++ * Serialization rules: |
933 |
++ * |
934 |
++ * Lock order: |
935 |
++ * |
936 |
++ * p->pi_lock |
937 |
++ * rq->lock |
938 |
++ * hrtimer_cpu_base->lock (hrtimer_start() for bandwidth controls) |
939 |
++ * |
940 |
++ * rq1->lock |
941 |
++ * rq2->lock where: rq1 < rq2 |
942 |
++ * |
943 |
++ * Regular state: |
944 |
++ * |
945 |
++ * Normal scheduling state is serialized by rq->lock. __schedule() takes the |
946 |
++ * local CPU's rq->lock, it optionally removes the task from the runqueue and |
947 |
++ * always looks at the local rq data structures to find the most eligible task |
948 |
++ * to run next. |
949 |
++ * |
950 |
++ * Task enqueue is also under rq->lock, possibly taken from another CPU. |
951 |
++ * Wakeups from another LLC domain might use an IPI to transfer the enqueue to |
952 |
++ * the local CPU to avoid bouncing the runqueue state around [ see |
953 |
++ * ttwu_queue_wakelist() ] |
954 |
++ * |
955 |
++ * Task wakeup, specifically wakeups that involve migration, are horribly |
956 |
++ * complicated to avoid having to take two rq->locks. |
957 |
++ * |
958 |
++ * Special state: |
959 |
++ * |
960 |
++ * System-calls and anything external will use task_rq_lock() which acquires |
961 |
++ * both p->pi_lock and rq->lock. As a consequence the state they change is |
962 |
++ * stable while holding either lock: |
963 |
++ * |
964 |
++ * - sched_setaffinity()/ |
965 |
++ * set_cpus_allowed_ptr(): p->cpus_ptr, p->nr_cpus_allowed |
966 |
++ * - set_user_nice(): p->se.load, p->*prio |
967 |
++ * - __sched_setscheduler(): p->sched_class, p->policy, p->*prio, |
968 |
++ * p->se.load, p->rt_priority, |
969 |
++ * p->dl.dl_{runtime, deadline, period, flags, bw, density} |
970 |
++ * - sched_setnuma(): p->numa_preferred_nid |
971 |
++ * - sched_move_task()/ |
972 |
++ * cpu_cgroup_fork(): p->sched_task_group |
973 |
++ * - uclamp_update_active() p->uclamp* |
974 |
++ * |
975 |
++ * p->state <- TASK_*: |
976 |
++ * |
977 |
++ * is changed locklessly using set_current_state(), __set_current_state() or |
978 |
++ * set_special_state(), see their respective comments, or by |
979 |
++ * try_to_wake_up(). This latter uses p->pi_lock to serialize against |
980 |
++ * concurrent self. |
981 |
++ * |
982 |
++ * p->on_rq <- { 0, 1 = TASK_ON_RQ_QUEUED, 2 = TASK_ON_RQ_MIGRATING }: |
983 |
++ * |
984 |
++ * is set by activate_task() and cleared by deactivate_task(), under |
985 |
++ * rq->lock. Non-zero indicates the task is runnable, the special |
986 |
++ * ON_RQ_MIGRATING state is used for migration without holding both |
987 |
++ * rq->locks. It indicates task_cpu() is not stable, see task_rq_lock(). |
988 |
++ * |
989 |
++ * p->on_cpu <- { 0, 1 }: |
990 |
++ * |
991 |
++ * is set by prepare_task() and cleared by finish_task() such that it will be |
992 |
++ * set before p is scheduled-in and cleared after p is scheduled-out, both |
993 |
++ * under rq->lock. Non-zero indicates the task is running on its CPU. |
994 |
++ * |
995 |
++ * [ The astute reader will observe that it is possible for two tasks on one |
996 |
++ * CPU to have ->on_cpu = 1 at the same time. ] |
997 |
++ * |
998 |
++ * task_cpu(p): is changed by set_task_cpu(), the rules are: |
999 |
++ * |
1000 |
++ * - Don't call set_task_cpu() on a blocked task: |
1001 |
++ * |
1002 |
++ * We don't care what CPU we're not running on, this simplifies hotplug, |
1003 |
++ * the CPU assignment of blocked tasks isn't required to be valid. |
1004 |
++ * |
1005 |
++ * - for try_to_wake_up(), called under p->pi_lock: |
1006 |
++ * |
1007 |
++ * This allows try_to_wake_up() to only take one rq->lock, see its comment. |
1008 |
++ * |
1009 |
++ * - for migration called under rq->lock: |
1010 |
++ * [ see task_on_rq_migrating() in task_rq_lock() ] |
1011 |
++ * |
1012 |
++ * o move_queued_task() |
1013 |
++ * o detach_task() |
1014 |
++ * |
1015 |
++ * - for migration called under double_rq_lock(): |
1016 |
++ * |
1017 |
++ * o __migrate_swap_task() |
1018 |
++ * o push_rt_task() / pull_rt_task() |
1019 |
++ * o push_dl_task() / pull_dl_task() |
1020 |
++ * o dl_task_offline_migration() |
1021 |
++ * |
1022 |
++ */ |
1023 |
++ |
1024 |
++/* |
1025 |
++ * Context: p->pi_lock |
1026 |
++ */ |
1027 |
++static inline struct rq |
1028 |
++*__task_access_lock(struct task_struct *p, raw_spinlock_t **plock) |
1029 |
++{ |
1030 |
++ struct rq *rq; |
1031 |
++ for (;;) { |
1032 |
++ rq = task_rq(p); |
1033 |
++ if (p->on_cpu || task_on_rq_queued(p)) { |
1034 |
++ raw_spin_lock(&rq->lock); |
1035 |
++ if (likely((p->on_cpu || task_on_rq_queued(p)) |
1036 |
++ && rq == task_rq(p))) { |
1037 |
++ *plock = &rq->lock; |
1038 |
++ return rq; |
1039 |
++ } |
1040 |
++ raw_spin_unlock(&rq->lock); |
1041 |
++ } else if (task_on_rq_migrating(p)) { |
1042 |
++ do { |
1043 |
++ cpu_relax(); |
1044 |
++ } while (unlikely(task_on_rq_migrating(p))); |
1045 |
++ } else { |
1046 |
++ *plock = NULL; |
1047 |
++ return rq; |
1048 |
++ } |
1049 |
++ } |
1050 |
++} |
1051 |
++ |
1052 |
++static inline void |
1053 |
++__task_access_unlock(struct task_struct *p, raw_spinlock_t *lock) |
1054 |
++{ |
1055 |
++ if (NULL != lock) |
1056 |
++ raw_spin_unlock(lock); |
1057 |
++} |
1058 |
++ |
1059 |
++static inline struct rq |
1060 |
++*task_access_lock_irqsave(struct task_struct *p, raw_spinlock_t **plock, |
1061 |
++ unsigned long *flags) |
1062 |
++{ |
1063 |
++ struct rq *rq; |
1064 |
++ for (;;) { |
1065 |
++ rq = task_rq(p); |
1066 |
++ if (p->on_cpu || task_on_rq_queued(p)) { |
1067 |
++ raw_spin_lock_irqsave(&rq->lock, *flags); |
1068 |
++ if (likely((p->on_cpu || task_on_rq_queued(p)) |
1069 |
++ && rq == task_rq(p))) { |
1070 |
++ *plock = &rq->lock; |
1071 |
++ return rq; |
1072 |
++ } |
1073 |
++ raw_spin_unlock_irqrestore(&rq->lock, *flags); |
1074 |
++ } else if (task_on_rq_migrating(p)) { |
1075 |
++ do { |
1076 |
++ cpu_relax(); |
1077 |
++ } while (unlikely(task_on_rq_migrating(p))); |
1078 |
++ } else { |
1079 |
++ raw_spin_lock_irqsave(&p->pi_lock, *flags); |
1080 |
++ if (likely(!p->on_cpu && !p->on_rq && |
1081 |
++ rq == task_rq(p))) { |
1082 |
++ *plock = &p->pi_lock; |
1083 |
++ return rq; |
1084 |
++ } |
1085 |
++ raw_spin_unlock_irqrestore(&p->pi_lock, *flags); |
1086 |
++ } |
1087 |
++ } |
1088 |
++} |
1089 |
++ |
1090 |
++static inline void |
1091 |
++task_access_unlock_irqrestore(struct task_struct *p, raw_spinlock_t *lock, |
1092 |
++ unsigned long *flags) |
1093 |
++{ |
1094 |
++ raw_spin_unlock_irqrestore(lock, *flags); |
1095 |
++} |
1096 |
++ |
1097 |
++/* |
1098 |
++ * __task_rq_lock - lock the rq @p resides on. |
1099 |
++ */ |
1100 |
++struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf) |
1101 |
++ __acquires(rq->lock) |
1102 |
++{ |
1103 |
++ struct rq *rq; |
1104 |
++ |
1105 |
++ lockdep_assert_held(&p->pi_lock); |
1106 |
++ |
1107 |
++ for (;;) { |
1108 |
++ rq = task_rq(p); |
1109 |
++ raw_spin_lock(&rq->lock); |
1110 |
++ if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) |
1111 |
++ return rq; |
1112 |
++ raw_spin_unlock(&rq->lock); |
1113 |
++ |
1114 |
++ while (unlikely(task_on_rq_migrating(p))) |
1115 |
++ cpu_relax(); |
1116 |
++ } |
1117 |
++} |
1118 |
++ |
1119 |
++/* |
1120 |
++ * task_rq_lock - lock p->pi_lock and lock the rq @p resides on. |
1121 |
++ */ |
1122 |
++struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) |
1123 |
++ __acquires(p->pi_lock) |
1124 |
++ __acquires(rq->lock) |
1125 |
++{ |
1126 |
++ struct rq *rq; |
1127 |
++ |
1128 |
++ for (;;) { |
1129 |
++ raw_spin_lock_irqsave(&p->pi_lock, rf->flags); |
1130 |
++ rq = task_rq(p); |
1131 |
++ raw_spin_lock(&rq->lock); |
1132 |
++ /* |
1133 |
++ * move_queued_task() task_rq_lock() |
1134 |
++ * |
1135 |
++ * ACQUIRE (rq->lock) |
1136 |
++ * [S] ->on_rq = MIGRATING [L] rq = task_rq() |
1137 |
++ * WMB (__set_task_cpu()) ACQUIRE (rq->lock); |
1138 |
++ * [S] ->cpu = new_cpu [L] task_rq() |
1139 |
++ * [L] ->on_rq |
1140 |
++ * RELEASE (rq->lock) |
1141 |
++ * |
1142 |
++ * If we observe the old CPU in task_rq_lock(), the acquire of |
1143 |
++ * the old rq->lock will fully serialize against the stores. |
1144 |
++ * |
1145 |
++ * If we observe the new CPU in task_rq_lock(), the address |
1146 |
++ * dependency headed by '[L] rq = task_rq()' and the acquire |
1147 |
++ * will pair with the WMB to ensure we then also see migrating. |
1148 |
++ */ |
1149 |
++ if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) { |
1150 |
++ return rq; |
1151 |
++ } |
1152 |
++ raw_spin_unlock(&rq->lock); |
1153 |
++ raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags); |
1154 |
++ |
1155 |
++ while (unlikely(task_on_rq_migrating(p))) |
1156 |
++ cpu_relax(); |
1157 |
++ } |
1158 |
++} |
1159 |
++ |
1160 |
++static inline void |
1161 |
++rq_lock_irqsave(struct rq *rq, struct rq_flags *rf) |
1162 |
++ __acquires(rq->lock) |
1163 |
++{ |
1164 |
++ raw_spin_lock_irqsave(&rq->lock, rf->flags); |
1165 |
++} |
1166 |
++ |
1167 |
++static inline void |
1168 |
++rq_unlock_irqrestore(struct rq *rq, struct rq_flags *rf) |
1169 |
++ __releases(rq->lock) |
1170 |
++{ |
1171 |
++ raw_spin_unlock_irqrestore(&rq->lock, rf->flags); |
1172 |
++} |
1173 |
++ |
1174 |
++void raw_spin_rq_lock_nested(struct rq *rq, int subclass) |
1175 |
++{ |
1176 |
++ raw_spinlock_t *lock; |
1177 |
++ |
1178 |
++ /* Matches synchronize_rcu() in __sched_core_enable() */ |
1179 |
++ preempt_disable(); |
1180 |
++ |
1181 |
++ for (;;) { |
1182 |
++ lock = __rq_lockp(rq); |
1183 |
++ raw_spin_lock_nested(lock, subclass); |
1184 |
++ if (likely(lock == __rq_lockp(rq))) { |
1185 |
++ /* preempt_count *MUST* be > 1 */ |
1186 |
++ preempt_enable_no_resched(); |
1187 |
++ return; |
1188 |
++ } |
1189 |
++ raw_spin_unlock(lock); |
1190 |
++ } |
1191 |
++} |
1192 |
++ |
1193 |
++void raw_spin_rq_unlock(struct rq *rq) |
1194 |
++{ |
1195 |
++ raw_spin_unlock(rq_lockp(rq)); |
1196 |
++} |
1197 |
++ |
1198 |
++/* |
1199 |
++ * RQ-clock updating methods: |
1200 |
++ */ |
1201 |
++ |
1202 |
++static void update_rq_clock_task(struct rq *rq, s64 delta) |
1203 |
++{ |
1204 |
++/* |
1205 |
++ * In theory, the compile should just see 0 here, and optimize out the call |
1206 |
++ * to sched_rt_avg_update. But I don't trust it... |
1207 |
++ */ |
1208 |
++ s64 __maybe_unused steal = 0, irq_delta = 0; |
1209 |
++ |
1210 |
++#ifdef CONFIG_IRQ_TIME_ACCOUNTING |
1211 |
++ irq_delta = irq_time_read(cpu_of(rq)) - rq->prev_irq_time; |
1212 |
++ |
1213 |
++ /* |
1214 |
++ * Since irq_time is only updated on {soft,}irq_exit, we might run into |
1215 |
++ * this case when a previous update_rq_clock() happened inside a |
1216 |
++ * {soft,}irq region. |
1217 |
++ * |
1218 |
++ * When this happens, we stop ->clock_task and only update the |
1219 |
++ * prev_irq_time stamp to account for the part that fit, so that a next |
1220 |
++ * update will consume the rest. This ensures ->clock_task is |
1221 |
++ * monotonic. |
1222 |
++ * |
1223 |
++ * It does however cause some slight miss-attribution of {soft,}irq |
1224 |
++ * time, a more accurate solution would be to update the irq_time using |
1225 |
++ * the current rq->clock timestamp, except that would require using |
1226 |
++ * atomic ops. |
1227 |
++ */ |
1228 |
++ if (irq_delta > delta) |
1229 |
++ irq_delta = delta; |
1230 |
++ |
1231 |
++ rq->prev_irq_time += irq_delta; |
1232 |
++ delta -= irq_delta; |
1233 |
++#endif |
1234 |
++#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING |
1235 |
++ if (static_key_false((¶virt_steal_rq_enabled))) { |
1236 |
++ steal = paravirt_steal_clock(cpu_of(rq)); |
1237 |
++ steal -= rq->prev_steal_time_rq; |
1238 |
++ |
1239 |
++ if (unlikely(steal > delta)) |
1240 |
++ steal = delta; |
1241 |
++ |
1242 |
++ rq->prev_steal_time_rq += steal; |
1243 |
++ delta -= steal; |
1244 |
++ } |
1245 |
++#endif |
1246 |
++ |
1247 |
++ rq->clock_task += delta; |
1248 |
++ |
1249 |
++#ifdef CONFIG_HAVE_SCHED_AVG_IRQ |
1250 |
++ if ((irq_delta + steal)) |
1251 |
++ update_irq_load_avg(rq, irq_delta + steal); |
1252 |
++#endif |
1253 |
++} |
1254 |
++ |
1255 |
++static inline void update_rq_clock(struct rq *rq) |
1256 |
++{ |
1257 |
++ s64 delta = sched_clock_cpu(cpu_of(rq)) - rq->clock; |
1258 |
++ |
1259 |
++ if (unlikely(delta <= 0)) |
1260 |
++ return; |
1261 |
++ rq->clock += delta; |
1262 |
++ update_rq_time_edge(rq); |
1263 |
++ update_rq_clock_task(rq, delta); |
1264 |
++} |
1265 |
++ |
1266 |
++/* |
1267 |
++ * RQ Load update routine |
1268 |
++ */ |
1269 |
++#define RQ_LOAD_HISTORY_BITS (sizeof(s32) * 8ULL) |
1270 |
++#define RQ_UTIL_SHIFT (8) |
1271 |
++#define RQ_LOAD_HISTORY_TO_UTIL(l) (((l) >> (RQ_LOAD_HISTORY_BITS - 1 - RQ_UTIL_SHIFT)) & 0xff) |
1272 |
++ |
1273 |
++#define LOAD_BLOCK(t) ((t) >> 17) |
1274 |
++#define LOAD_HALF_BLOCK(t) ((t) >> 16) |
1275 |
++#define BLOCK_MASK(t) ((t) & ((0x01 << 18) - 1)) |
1276 |
++#define LOAD_BLOCK_BIT(b) (1UL << (RQ_LOAD_HISTORY_BITS - 1 - (b))) |
1277 |
++#define CURRENT_LOAD_BIT LOAD_BLOCK_BIT(0) |
1278 |
++ |
1279 |
++static inline void rq_load_update(struct rq *rq) |
1280 |
++{ |
1281 |
++ u64 time = rq->clock; |
1282 |
++ u64 delta = min(LOAD_BLOCK(time) - LOAD_BLOCK(rq->load_stamp), |
1283 |
++ RQ_LOAD_HISTORY_BITS - 1); |
1284 |
++ u64 prev = !!(rq->load_history & CURRENT_LOAD_BIT); |
1285 |
++ u64 curr = !!rq->nr_running; |
1286 |
++ |
1287 |
++ if (delta) { |
1288 |
++ rq->load_history = rq->load_history >> delta; |
1289 |
++ |
1290 |
++ if (delta < RQ_UTIL_SHIFT) { |
1291 |
++ rq->load_block += (~BLOCK_MASK(rq->load_stamp)) * prev; |
1292 |
++ if (!!LOAD_HALF_BLOCK(rq->load_block) ^ curr) |
1293 |
++ rq->load_history ^= LOAD_BLOCK_BIT(delta); |
1294 |
++ } |
1295 |
++ |
1296 |
++ rq->load_block = BLOCK_MASK(time) * prev; |
1297 |
++ } else { |
1298 |
++ rq->load_block += (time - rq->load_stamp) * prev; |
1299 |
++ } |
1300 |
++ if (prev ^ curr) |
1301 |
++ rq->load_history ^= CURRENT_LOAD_BIT; |
1302 |
++ rq->load_stamp = time; |
1303 |
++} |
1304 |
++ |
1305 |
++unsigned long rq_load_util(struct rq *rq, unsigned long max) |
1306 |
++{ |
1307 |
++ return RQ_LOAD_HISTORY_TO_UTIL(rq->load_history) * (max >> RQ_UTIL_SHIFT); |
1308 |
++} |
1309 |
++ |
1310 |
++#ifdef CONFIG_SMP |
1311 |
++unsigned long sched_cpu_util(int cpu, unsigned long max) |
1312 |
++{ |
1313 |
++ return rq_load_util(cpu_rq(cpu), max); |
1314 |
++} |
1315 |
++#endif /* CONFIG_SMP */ |
1316 |
++ |
1317 |
++#ifdef CONFIG_CPU_FREQ |
1318 |
++/** |
1319 |
++ * cpufreq_update_util - Take a note about CPU utilization changes. |
1320 |
++ * @rq: Runqueue to carry out the update for. |
1321 |
++ * @flags: Update reason flags. |
1322 |
++ * |
1323 |
++ * This function is called by the scheduler on the CPU whose utilization is |
1324 |
++ * being updated. |
1325 |
++ * |
1326 |
++ * It can only be called from RCU-sched read-side critical sections. |
1327 |
++ * |
1328 |
++ * The way cpufreq is currently arranged requires it to evaluate the CPU |
1329 |
++ * performance state (frequency/voltage) on a regular basis to prevent it from |
1330 |
++ * being stuck in a completely inadequate performance level for too long. |
1331 |
++ * That is not guaranteed to happen if the updates are only triggered from CFS |
1332 |
++ * and DL, though, because they may not be coming in if only RT tasks are |
1333 |
++ * active all the time (or there are RT tasks only). |
1334 |
++ * |
1335 |
++ * As a workaround for that issue, this function is called periodically by the |
1336 |
++ * RT sched class to trigger extra cpufreq updates to prevent it from stalling, |
1337 |
++ * but that really is a band-aid. Going forward it should be replaced with |
1338 |
++ * solutions targeted more specifically at RT tasks. |
1339 |
++ */ |
1340 |
++static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) |
1341 |
++{ |
1342 |
++ struct update_util_data *data; |
1343 |
++ |
1344 |
++#ifdef CONFIG_SMP |
1345 |
++ rq_load_update(rq); |
1346 |
++#endif |
1347 |
++ data = rcu_dereference_sched(*per_cpu_ptr(&cpufreq_update_util_data, |
1348 |
++ cpu_of(rq))); |
1349 |
++ if (data) |
1350 |
++ data->func(data, rq_clock(rq), flags); |
1351 |
++} |
1352 |
++#else |
1353 |
++static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) |
1354 |
++{ |
1355 |
++#ifdef CONFIG_SMP |
1356 |
++ rq_load_update(rq); |
1357 |
++#endif |
1358 |
++} |
1359 |
++#endif /* CONFIG_CPU_FREQ */ |
1360 |
++ |
1361 |
++#ifdef CONFIG_NO_HZ_FULL |
1362 |
++/* |
1363 |
++ * Tick may be needed by tasks in the runqueue depending on their policy and |
1364 |
++ * requirements. If tick is needed, lets send the target an IPI to kick it out |
1365 |
++ * of nohz mode if necessary. |
1366 |
++ */ |
1367 |
++static inline void sched_update_tick_dependency(struct rq *rq) |
1368 |
++{ |
1369 |
++ int cpu = cpu_of(rq); |
1370 |
++ |
1371 |
++ if (!tick_nohz_full_cpu(cpu)) |
1372 |
++ return; |
1373 |
++ |
1374 |
++ if (rq->nr_running < 2) |
1375 |
++ tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED); |
1376 |
++ else |
1377 |
++ tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED); |
1378 |
++} |
1379 |
++#else /* !CONFIG_NO_HZ_FULL */ |
1380 |
++static inline void sched_update_tick_dependency(struct rq *rq) { } |
1381 |
++#endif |
1382 |
++ |
1383 |
++bool sched_task_on_rq(struct task_struct *p) |
1384 |
++{ |
1385 |
++ return task_on_rq_queued(p); |
1386 |
++} |
1387 |
++ |
1388 |
++unsigned long get_wchan(struct task_struct *p) |
1389 |
++{ |
1390 |
++ unsigned long ip = 0; |
1391 |
++ unsigned int state; |
1392 |
++ |
1393 |
++ if (!p || p == current) |
1394 |
++ return 0; |
1395 |
++ |
1396 |
++ /* Only get wchan if task is blocked and we can keep it that way. */ |
1397 |
++ raw_spin_lock_irq(&p->pi_lock); |
1398 |
++ state = READ_ONCE(p->__state); |
1399 |
++ smp_rmb(); /* see try_to_wake_up() */ |
1400 |
++ if (state != TASK_RUNNING && state != TASK_WAKING && !p->on_rq) |
1401 |
++ ip = __get_wchan(p); |
1402 |
++ raw_spin_unlock_irq(&p->pi_lock); |
1403 |
++ |
1404 |
++ return ip; |
1405 |
++} |
1406 |
++ |
1407 |
++/* |
1408 |
++ * Add/Remove/Requeue task to/from the runqueue routines |
1409 |
++ * Context: rq->lock |
1410 |
++ */ |
1411 |
++#define __SCHED_DEQUEUE_TASK(p, rq, flags) \ |
1412 |
++ psi_dequeue(p, flags & DEQUEUE_SLEEP); \ |
1413 |
++ sched_info_dequeue(rq, p); \ |
1414 |
++ \ |
1415 |
++ list_del(&p->sq_node); \ |
1416 |
++ if (list_empty(&rq->queue.heads[p->sq_idx])) \ |
1417 |
++ clear_bit(sched_idx2prio(p->sq_idx, rq), rq->queue.bitmap); |
1418 |
++ |
1419 |
++#define __SCHED_ENQUEUE_TASK(p, rq, flags) \ |
1420 |
++ sched_info_enqueue(rq, p); \ |
1421 |
++ psi_enqueue(p, flags); \ |
1422 |
++ \ |
1423 |
++ p->sq_idx = task_sched_prio_idx(p, rq); \ |
1424 |
++ list_add_tail(&p->sq_node, &rq->queue.heads[p->sq_idx]); \ |
1425 |
++ set_bit(sched_idx2prio(p->sq_idx, rq), rq->queue.bitmap); |
1426 |
++ |
1427 |
++static inline void dequeue_task(struct task_struct *p, struct rq *rq, int flags) |
1428 |
++{ |
1429 |
++ lockdep_assert_held(&rq->lock); |
1430 |
++ |
1431 |
++ /*printk(KERN_INFO "sched: dequeue(%d) %px %016llx\n", cpu_of(rq), p, p->priodl);*/ |
1432 |
++ WARN_ONCE(task_rq(p) != rq, "sched: dequeue task reside on cpu%d from cpu%d\n", |
1433 |
++ task_cpu(p), cpu_of(rq)); |
1434 |
++ |
1435 |
++ __SCHED_DEQUEUE_TASK(p, rq, flags); |
1436 |
++ --rq->nr_running; |
1437 |
++#ifdef CONFIG_SMP |
1438 |
++ if (1 == rq->nr_running) |
1439 |
++ cpumask_clear_cpu(cpu_of(rq), &sched_rq_pending_mask); |
1440 |
++#endif |
1441 |
++ |
1442 |
++ sched_update_tick_dependency(rq); |
1443 |
++} |
1444 |
++ |
1445 |
++static inline void enqueue_task(struct task_struct *p, struct rq *rq, int flags) |
1446 |
++{ |
1447 |
++ lockdep_assert_held(&rq->lock); |
1448 |
++ |
1449 |
++ /*printk(KERN_INFO "sched: enqueue(%d) %px %016llx\n", cpu_of(rq), p, p->priodl);*/ |
1450 |
++ WARN_ONCE(task_rq(p) != rq, "sched: enqueue task reside on cpu%d to cpu%d\n", |
1451 |
++ task_cpu(p), cpu_of(rq)); |
1452 |
++ |
1453 |
++ __SCHED_ENQUEUE_TASK(p, rq, flags); |
1454 |
++ update_sched_rq_watermark(rq); |
1455 |
++ ++rq->nr_running; |
1456 |
++#ifdef CONFIG_SMP |
1457 |
++ if (2 == rq->nr_running) |
1458 |
++ cpumask_set_cpu(cpu_of(rq), &sched_rq_pending_mask); |
1459 |
++#endif |
1460 |
++ |
1461 |
++ sched_update_tick_dependency(rq); |
1462 |
++} |
1463 |
++ |
1464 |
++static inline void requeue_task(struct task_struct *p, struct rq *rq, int idx) |
1465 |
++{ |
1466 |
++ lockdep_assert_held(&rq->lock); |
1467 |
++ /*printk(KERN_INFO "sched: requeue(%d) %px %016llx\n", cpu_of(rq), p, p->priodl);*/ |
1468 |
++ WARN_ONCE(task_rq(p) != rq, "sched: cpu[%d] requeue task reside on cpu%d\n", |
1469 |
++ cpu_of(rq), task_cpu(p)); |
1470 |
++ |
1471 |
++ list_del(&p->sq_node); |
1472 |
++ list_add_tail(&p->sq_node, &rq->queue.heads[idx]); |
1473 |
++ if (idx != p->sq_idx) { |
1474 |
++ if (list_empty(&rq->queue.heads[p->sq_idx])) |
1475 |
++ clear_bit(sched_idx2prio(p->sq_idx, rq), |
1476 |
++ rq->queue.bitmap); |
1477 |
++ p->sq_idx = idx; |
1478 |
++ set_bit(sched_idx2prio(p->sq_idx, rq), rq->queue.bitmap); |
1479 |
++ update_sched_rq_watermark(rq); |
1480 |
++ } |
1481 |
++} |
1482 |
++ |
1483 |
++/* |
1484 |
++ * cmpxchg based fetch_or, macro so it works for different integer types |
1485 |
++ */ |
1486 |
++#define fetch_or(ptr, mask) \ |
1487 |
++ ({ \ |
1488 |
++ typeof(ptr) _ptr = (ptr); \ |
1489 |
++ typeof(mask) _mask = (mask); \ |
1490 |
++ typeof(*_ptr) _old, _val = *_ptr; \ |
1491 |
++ \ |
1492 |
++ for (;;) { \ |
1493 |
++ _old = cmpxchg(_ptr, _val, _val | _mask); \ |
1494 |
++ if (_old == _val) \ |
1495 |
++ break; \ |
1496 |
++ _val = _old; \ |
1497 |
++ } \ |
1498 |
++ _old; \ |
1499 |
++}) |
1500 |
++ |
1501 |
++#if defined(CONFIG_SMP) && defined(TIF_POLLING_NRFLAG) |
1502 |
++/* |
1503 |
++ * Atomically set TIF_NEED_RESCHED and test for TIF_POLLING_NRFLAG, |
1504 |
++ * this avoids any races wrt polling state changes and thereby avoids |
1505 |
++ * spurious IPIs. |
1506 |
++ */ |
1507 |
++static bool set_nr_and_not_polling(struct task_struct *p) |
1508 |
++{ |
1509 |
++ struct thread_info *ti = task_thread_info(p); |
1510 |
++ return !(fetch_or(&ti->flags, _TIF_NEED_RESCHED) & _TIF_POLLING_NRFLAG); |
1511 |
++} |
1512 |
++ |
1513 |
++/* |
1514 |
++ * Atomically set TIF_NEED_RESCHED if TIF_POLLING_NRFLAG is set. |
1515 |
++ * |
1516 |
++ * If this returns true, then the idle task promises to call |
1517 |
++ * sched_ttwu_pending() and reschedule soon. |
1518 |
++ */ |
1519 |
++static bool set_nr_if_polling(struct task_struct *p) |
1520 |
++{ |
1521 |
++ struct thread_info *ti = task_thread_info(p); |
1522 |
++ typeof(ti->flags) old, val = READ_ONCE(ti->flags); |
1523 |
++ |
1524 |
++ for (;;) { |
1525 |
++ if (!(val & _TIF_POLLING_NRFLAG)) |
1526 |
++ return false; |
1527 |
++ if (val & _TIF_NEED_RESCHED) |
1528 |
++ return true; |
1529 |
++ old = cmpxchg(&ti->flags, val, val | _TIF_NEED_RESCHED); |
1530 |
++ if (old == val) |
1531 |
++ break; |
1532 |
++ val = old; |
1533 |
++ } |
1534 |
++ return true; |
1535 |
++} |
1536 |
++ |
1537 |
++#else |
1538 |
++static bool set_nr_and_not_polling(struct task_struct *p) |
1539 |
++{ |
1540 |
++ set_tsk_need_resched(p); |
1541 |
++ return true; |
1542 |
++} |
1543 |
++ |
1544 |
++#ifdef CONFIG_SMP |
1545 |
++static bool set_nr_if_polling(struct task_struct *p) |
1546 |
++{ |
1547 |
++ return false; |
1548 |
++} |
1549 |
++#endif |
1550 |
++#endif |
1551 |
++ |
1552 |
++static bool __wake_q_add(struct wake_q_head *head, struct task_struct *task) |
1553 |
++{ |
1554 |
++ struct wake_q_node *node = &task->wake_q; |
1555 |
++ |
1556 |
++ /* |
1557 |
++ * Atomically grab the task, if ->wake_q is !nil already it means |
1558 |
++ * it's already queued (either by us or someone else) and will get the |
1559 |
++ * wakeup due to that. |
1560 |
++ * |
1561 |
++ * In order to ensure that a pending wakeup will observe our pending |
1562 |
++ * state, even in the failed case, an explicit smp_mb() must be used. |
1563 |
++ */ |
1564 |
++ smp_mb__before_atomic(); |
1565 |
++ if (unlikely(cmpxchg_relaxed(&node->next, NULL, WAKE_Q_TAIL))) |
1566 |
++ return false; |
1567 |
++ |
1568 |
++ /* |
1569 |
++ * The head is context local, there can be no concurrency. |
1570 |
++ */ |
1571 |
++ *head->lastp = node; |
1572 |
++ head->lastp = &node->next; |
1573 |
++ return true; |
1574 |
++} |
1575 |
++ |
1576 |
++/** |
1577 |
++ * wake_q_add() - queue a wakeup for 'later' waking. |
1578 |
++ * @head: the wake_q_head to add @task to |
1579 |
++ * @task: the task to queue for 'later' wakeup |
1580 |
++ * |
1581 |
++ * Queue a task for later wakeup, most likely by the wake_up_q() call in the |
1582 |
++ * same context, _HOWEVER_ this is not guaranteed, the wakeup can come |
1583 |
++ * instantly. |
1584 |
++ * |
1585 |
++ * This function must be used as-if it were wake_up_process(); IOW the task |
1586 |
++ * must be ready to be woken at this location. |
1587 |
++ */ |
1588 |
++void wake_q_add(struct wake_q_head *head, struct task_struct *task) |
1589 |
++{ |
1590 |
++ if (__wake_q_add(head, task)) |
1591 |
++ get_task_struct(task); |
1592 |
++} |
1593 |
++ |
1594 |
++/** |
1595 |
++ * wake_q_add_safe() - safely queue a wakeup for 'later' waking. |
1596 |
++ * @head: the wake_q_head to add @task to |
1597 |
++ * @task: the task to queue for 'later' wakeup |
1598 |
++ * |
1599 |
++ * Queue a task for later wakeup, most likely by the wake_up_q() call in the |
1600 |
++ * same context, _HOWEVER_ this is not guaranteed, the wakeup can come |
1601 |
++ * instantly. |
1602 |
++ * |
1603 |
++ * This function must be used as-if it were wake_up_process(); IOW the task |
1604 |
++ * must be ready to be woken at this location. |
1605 |
++ * |
1606 |
++ * This function is essentially a task-safe equivalent to wake_q_add(). Callers |
1607 |
++ * that already hold reference to @task can call the 'safe' version and trust |
1608 |
++ * wake_q to do the right thing depending whether or not the @task is already |
1609 |
++ * queued for wakeup. |
1610 |
++ */ |
1611 |
++void wake_q_add_safe(struct wake_q_head *head, struct task_struct *task) |
1612 |
++{ |
1613 |
++ if (!__wake_q_add(head, task)) |
1614 |
++ put_task_struct(task); |
1615 |
++} |
1616 |
++ |
1617 |
++void wake_up_q(struct wake_q_head *head) |
1618 |
++{ |
1619 |
++ struct wake_q_node *node = head->first; |
1620 |
++ |
1621 |
++ while (node != WAKE_Q_TAIL) { |
1622 |
++ struct task_struct *task; |
1623 |
++ |
1624 |
++ task = container_of(node, struct task_struct, wake_q); |
1625 |
++ /* task can safely be re-inserted now: */ |
1626 |
++ node = node->next; |
1627 |
++ task->wake_q.next = NULL; |
1628 |
++ |
1629 |
++ /* |
1630 |
++ * wake_up_process() executes a full barrier, which pairs with |
1631 |
++ * the queueing in wake_q_add() so as not to miss wakeups. |
1632 |
++ */ |
1633 |
++ wake_up_process(task); |
1634 |
++ put_task_struct(task); |
1635 |
++ } |
1636 |
++} |
1637 |
++ |
1638 |
++/* |
1639 |
++ * resched_curr - mark rq's current task 'to be rescheduled now'. |
1640 |
++ * |
1641 |
++ * On UP this means the setting of the need_resched flag, on SMP it |
1642 |
++ * might also involve a cross-CPU call to trigger the scheduler on |
1643 |
++ * the target CPU. |
1644 |
++ */ |
1645 |
++void resched_curr(struct rq *rq) |
1646 |
++{ |
1647 |
++ struct task_struct *curr = rq->curr; |
1648 |
++ int cpu; |
1649 |
++ |
1650 |
++ lockdep_assert_held(&rq->lock); |
1651 |
++ |
1652 |
++ if (test_tsk_need_resched(curr)) |
1653 |
++ return; |
1654 |
++ |
1655 |
++ cpu = cpu_of(rq); |
1656 |
++ if (cpu == smp_processor_id()) { |
1657 |
++ set_tsk_need_resched(curr); |
1658 |
++ set_preempt_need_resched(); |
1659 |
++ return; |
1660 |
++ } |
1661 |
++ |
1662 |
++ if (set_nr_and_not_polling(curr)) |
1663 |
++ smp_send_reschedule(cpu); |
1664 |
++ else |
1665 |
++ trace_sched_wake_idle_without_ipi(cpu); |
1666 |
++} |
1667 |
++ |
1668 |
++void resched_cpu(int cpu) |
1669 |
++{ |
1670 |
++ struct rq *rq = cpu_rq(cpu); |
1671 |
++ unsigned long flags; |
1672 |
++ |
1673 |
++ raw_spin_lock_irqsave(&rq->lock, flags); |
1674 |
++ if (cpu_online(cpu) || cpu == smp_processor_id()) |
1675 |
++ resched_curr(cpu_rq(cpu)); |
1676 |
++ raw_spin_unlock_irqrestore(&rq->lock, flags); |
1677 |
++} |
1678 |
++ |
1679 |
++#ifdef CONFIG_SMP |
1680 |
++#ifdef CONFIG_NO_HZ_COMMON |
1681 |
++void nohz_balance_enter_idle(int cpu) {} |
1682 |
++ |
1683 |
++void select_nohz_load_balancer(int stop_tick) {} |
1684 |
++ |
1685 |
++void set_cpu_sd_state_idle(void) {} |
1686 |
++ |
1687 |
++/* |
1688 |
++ * In the semi idle case, use the nearest busy CPU for migrating timers |
1689 |
++ * from an idle CPU. This is good for power-savings. |
1690 |
++ * |
1691 |
++ * We don't do similar optimization for completely idle system, as |
1692 |
++ * selecting an idle CPU will add more delays to the timers than intended |
1693 |
++ * (as that CPU's timer base may not be uptodate wrt jiffies etc). |
1694 |
++ */ |
1695 |
++int get_nohz_timer_target(void) |
1696 |
++{ |
1697 |
++ int i, cpu = smp_processor_id(), default_cpu = -1; |
1698 |
++ struct cpumask *mask; |
1699 |
++ const struct cpumask *hk_mask; |
1700 |
++ |
1701 |
++ if (housekeeping_cpu(cpu, HK_TYPE_TIMER)) { |
1702 |
++ if (!idle_cpu(cpu)) |
1703 |
++ return cpu; |
1704 |
++ default_cpu = cpu; |
1705 |
++ } |
1706 |
++ |
1707 |
++ hk_mask = housekeeping_cpumask(HK_TYPE_TIMER); |
1708 |
++ |
1709 |
++ for (mask = per_cpu(sched_cpu_topo_masks, cpu) + 1; |
1710 |
++ mask < per_cpu(sched_cpu_topo_end_mask, cpu); mask++) |
1711 |
++ for_each_cpu_and(i, mask, hk_mask) |
1712 |
++ if (!idle_cpu(i)) |
1713 |
++ return i; |
1714 |
++ |
1715 |
++ if (default_cpu == -1) |
1716 |
++ default_cpu = housekeeping_any_cpu(HK_TYPE_TIMER); |
1717 |
++ cpu = default_cpu; |
1718 |
++ |
1719 |
++ return cpu; |
1720 |
++} |
1721 |
++ |
1722 |
++/* |
1723 |
++ * When add_timer_on() enqueues a timer into the timer wheel of an |
1724 |
++ * idle CPU then this timer might expire before the next timer event |
1725 |
++ * which is scheduled to wake up that CPU. In case of a completely |
1726 |
++ * idle system the next event might even be infinite time into the |
1727 |
++ * future. wake_up_idle_cpu() ensures that the CPU is woken up and |
1728 |
++ * leaves the inner idle loop so the newly added timer is taken into |
1729 |
++ * account when the CPU goes back to idle and evaluates the timer |
1730 |
++ * wheel for the next timer event. |
1731 |
++ */ |
1732 |
++static inline void wake_up_idle_cpu(int cpu) |
1733 |
++{ |
1734 |
++ struct rq *rq = cpu_rq(cpu); |
1735 |
++ |
1736 |
++ if (cpu == smp_processor_id()) |
1737 |
++ return; |
1738 |
++ |
1739 |
++ if (set_nr_and_not_polling(rq->idle)) |
1740 |
++ smp_send_reschedule(cpu); |
1741 |
++ else |
1742 |
++ trace_sched_wake_idle_without_ipi(cpu); |
1743 |
++} |
1744 |
++ |
1745 |
++static inline bool wake_up_full_nohz_cpu(int cpu) |
1746 |
++{ |
1747 |
++ /* |
1748 |
++ * We just need the target to call irq_exit() and re-evaluate |
1749 |
++ * the next tick. The nohz full kick at least implies that. |
1750 |
++ * If needed we can still optimize that later with an |
1751 |
++ * empty IRQ. |
1752 |
++ */ |
1753 |
++ if (cpu_is_offline(cpu)) |
1754 |
++ return true; /* Don't try to wake offline CPUs. */ |
1755 |
++ if (tick_nohz_full_cpu(cpu)) { |
1756 |
++ if (cpu != smp_processor_id() || |
1757 |
++ tick_nohz_tick_stopped()) |
1758 |
++ tick_nohz_full_kick_cpu(cpu); |
1759 |
++ return true; |
1760 |
++ } |
1761 |
++ |
1762 |
++ return false; |
1763 |
++} |
1764 |
++ |
1765 |
++void wake_up_nohz_cpu(int cpu) |
1766 |
++{ |
1767 |
++ if (!wake_up_full_nohz_cpu(cpu)) |
1768 |
++ wake_up_idle_cpu(cpu); |
1769 |
++} |
1770 |
++ |
1771 |
++static void nohz_csd_func(void *info) |
1772 |
++{ |
1773 |
++ struct rq *rq = info; |
1774 |
++ int cpu = cpu_of(rq); |
1775 |
++ unsigned int flags; |
1776 |
++ |
1777 |
++ /* |
1778 |
++ * Release the rq::nohz_csd. |
1779 |
++ */ |
1780 |
++ flags = atomic_fetch_andnot(NOHZ_KICK_MASK, nohz_flags(cpu)); |
1781 |
++ WARN_ON(!(flags & NOHZ_KICK_MASK)); |
1782 |
++ |
1783 |
++ rq->idle_balance = idle_cpu(cpu); |
1784 |
++ if (rq->idle_balance && !need_resched()) { |
1785 |
++ rq->nohz_idle_balance = flags; |
1786 |
++ raise_softirq_irqoff(SCHED_SOFTIRQ); |
1787 |
++ } |
1788 |
++} |
1789 |
++ |
1790 |
++#endif /* CONFIG_NO_HZ_COMMON */ |
1791 |
++#endif /* CONFIG_SMP */ |
1792 |
++ |
1793 |
++static inline void check_preempt_curr(struct rq *rq) |
1794 |
++{ |
1795 |
++ if (sched_rq_first_task(rq) != rq->curr) |
1796 |
++ resched_curr(rq); |
1797 |
++} |
1798 |
++ |
1799 |
++#ifdef CONFIG_SCHED_HRTICK |
1800 |
++/* |
1801 |
++ * Use HR-timers to deliver accurate preemption points. |
1802 |
++ */ |
1803 |
++ |
1804 |
++static void hrtick_clear(struct rq *rq) |
1805 |
++{ |
1806 |
++ if (hrtimer_active(&rq->hrtick_timer)) |
1807 |
++ hrtimer_cancel(&rq->hrtick_timer); |
1808 |
++} |
1809 |
++ |
1810 |
++/* |
1811 |
++ * High-resolution timer tick. |
1812 |
++ * Runs from hardirq context with interrupts disabled. |
1813 |
++ */ |
1814 |
++static enum hrtimer_restart hrtick(struct hrtimer *timer) |
1815 |
++{ |
1816 |
++ struct rq *rq = container_of(timer, struct rq, hrtick_timer); |
1817 |
++ |
1818 |
++ WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); |
1819 |
++ |
1820 |
++ raw_spin_lock(&rq->lock); |
1821 |
++ resched_curr(rq); |
1822 |
++ raw_spin_unlock(&rq->lock); |
1823 |
++ |
1824 |
++ return HRTIMER_NORESTART; |
1825 |
++} |
1826 |
++ |
1827 |
++/* |
1828 |
++ * Use hrtick when: |
1829 |
++ * - enabled by features |
1830 |
++ * - hrtimer is actually high res |
1831 |
++ */ |
1832 |
++static inline int hrtick_enabled(struct rq *rq) |
1833 |
++{ |
1834 |
++ /** |
1835 |
++ * Alt schedule FW doesn't support sched_feat yet |
1836 |
++ if (!sched_feat(HRTICK)) |
1837 |
++ return 0; |
1838 |
++ */ |
1839 |
++ if (!cpu_active(cpu_of(rq))) |
1840 |
++ return 0; |
1841 |
++ return hrtimer_is_hres_active(&rq->hrtick_timer); |
1842 |
++} |
1843 |
++ |
1844 |
++#ifdef CONFIG_SMP |
1845 |
++ |
1846 |
++static void __hrtick_restart(struct rq *rq) |
1847 |
++{ |
1848 |
++ struct hrtimer *timer = &rq->hrtick_timer; |
1849 |
++ ktime_t time = rq->hrtick_time; |
1850 |
++ |
1851 |
++ hrtimer_start(timer, time, HRTIMER_MODE_ABS_PINNED_HARD); |
1852 |
++} |
1853 |
++ |
1854 |
++/* |
1855 |
++ * called from hardirq (IPI) context |
1856 |
++ */ |
1857 |
++static void __hrtick_start(void *arg) |
1858 |
++{ |
1859 |
++ struct rq *rq = arg; |
1860 |
++ |
1861 |
++ raw_spin_lock(&rq->lock); |
1862 |
++ __hrtick_restart(rq); |
1863 |
++ raw_spin_unlock(&rq->lock); |
1864 |
++} |
1865 |
++ |
1866 |
++/* |
1867 |
++ * Called to set the hrtick timer state. |
1868 |
++ * |
1869 |
++ * called with rq->lock held and irqs disabled |
1870 |
++ */ |
1871 |
++void hrtick_start(struct rq *rq, u64 delay) |
1872 |
++{ |
1873 |
++ struct hrtimer *timer = &rq->hrtick_timer; |
1874 |
++ s64 delta; |
1875 |
++ |
1876 |
++ /* |
1877 |
++ * Don't schedule slices shorter than 10000ns, that just |
1878 |
++ * doesn't make sense and can cause timer DoS. |
1879 |
++ */ |
1880 |
++ delta = max_t(s64, delay, 10000LL); |
1881 |
++ |
1882 |
++ rq->hrtick_time = ktime_add_ns(timer->base->get_time(), delta); |
1883 |
++ |
1884 |
++ if (rq == this_rq()) |
1885 |
++ __hrtick_restart(rq); |
1886 |
++ else |
1887 |
++ smp_call_function_single_async(cpu_of(rq), &rq->hrtick_csd); |
1888 |
++} |
1889 |
++ |
1890 |
++#else |
1891 |
++/* |
1892 |
++ * Called to set the hrtick timer state. |
1893 |
++ * |
1894 |
++ * called with rq->lock held and irqs disabled |
1895 |
++ */ |
1896 |
++void hrtick_start(struct rq *rq, u64 delay) |
1897 |
++{ |
1898 |
++ /* |
1899 |
++ * Don't schedule slices shorter than 10000ns, that just |
1900 |
++ * doesn't make sense. Rely on vruntime for fairness. |
1901 |
++ */ |
1902 |
++ delay = max_t(u64, delay, 10000LL); |
1903 |
++ hrtimer_start(&rq->hrtick_timer, ns_to_ktime(delay), |
1904 |
++ HRTIMER_MODE_REL_PINNED_HARD); |
1905 |
++} |
1906 |
++#endif /* CONFIG_SMP */ |
1907 |
++ |
1908 |
++static void hrtick_rq_init(struct rq *rq) |
1909 |
++{ |
1910 |
++#ifdef CONFIG_SMP |
1911 |
++ INIT_CSD(&rq->hrtick_csd, __hrtick_start, rq); |
1912 |
++#endif |
1913 |
++ |
1914 |
++ hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); |
1915 |
++ rq->hrtick_timer.function = hrtick; |
1916 |
++} |
1917 |
++#else /* CONFIG_SCHED_HRTICK */ |
1918 |
++static inline int hrtick_enabled(struct rq *rq) |
1919 |
++{ |
1920 |
++ return 0; |
1921 |
++} |
1922 |
++ |
1923 |
++static inline void hrtick_clear(struct rq *rq) |
1924 |
++{ |
1925 |
++} |
1926 |
++ |
1927 |
++static inline void hrtick_rq_init(struct rq *rq) |
1928 |
++{ |
1929 |
++} |
1930 |
++#endif /* CONFIG_SCHED_HRTICK */ |
1931 |
++ |
1932 |
++static inline int __normal_prio(int policy, int rt_prio, int static_prio) |
1933 |
++{ |
1934 |
++ return rt_policy(policy) ? (MAX_RT_PRIO - 1 - rt_prio) : |
1935 |
++ static_prio + MAX_PRIORITY_ADJ; |
1936 |
++} |
1937 |
++ |
1938 |
++/* |
1939 |
++ * Calculate the expected normal priority: i.e. priority |
1940 |
++ * without taking RT-inheritance into account. Might be |
1941 |
++ * boosted by interactivity modifiers. Changes upon fork, |
1942 |
++ * setprio syscalls, and whenever the interactivity |
1943 |
++ * estimator recalculates. |
1944 |
++ */ |
1945 |
++static inline int normal_prio(struct task_struct *p) |
1946 |
++{ |
1947 |
++ return __normal_prio(p->policy, p->rt_priority, p->static_prio); |
1948 |
++} |
1949 |
++ |
1950 |
++/* |
1951 |
++ * Calculate the current priority, i.e. the priority |
1952 |
++ * taken into account by the scheduler. This value might |
1953 |
++ * be boosted by RT tasks as it will be RT if the task got |
1954 |
++ * RT-boosted. If not then it returns p->normal_prio. |
1955 |
++ */ |
1956 |
++static int effective_prio(struct task_struct *p) |
1957 |
++{ |
1958 |
++ p->normal_prio = normal_prio(p); |
1959 |
++ /* |
1960 |
++ * If we are RT tasks or we were boosted to RT priority, |
1961 |
++ * keep the priority unchanged. Otherwise, update priority |
1962 |
++ * to the normal priority: |
1963 |
++ */ |
1964 |
++ if (!rt_prio(p->prio)) |
1965 |
++ return p->normal_prio; |
1966 |
++ return p->prio; |
1967 |
++} |
1968 |
++ |
1969 |
++/* |
1970 |
++ * activate_task - move a task to the runqueue. |
1971 |
++ * |
1972 |
++ * Context: rq->lock |
1973 |
++ */ |
1974 |
++static void activate_task(struct task_struct *p, struct rq *rq) |
1975 |
++{ |
1976 |
++ enqueue_task(p, rq, ENQUEUE_WAKEUP); |
1977 |
++ p->on_rq = TASK_ON_RQ_QUEUED; |
1978 |
++ |
1979 |
++ /* |
1980 |
++ * If in_iowait is set, the code below may not trigger any cpufreq |
1981 |
++ * utilization updates, so do it here explicitly with the IOWAIT flag |
1982 |
++ * passed. |
1983 |
++ */ |
1984 |
++ cpufreq_update_util(rq, SCHED_CPUFREQ_IOWAIT * p->in_iowait); |
1985 |
++} |
1986 |
++ |
1987 |
++/* |
1988 |
++ * deactivate_task - remove a task from the runqueue. |
1989 |
++ * |
1990 |
++ * Context: rq->lock |
1991 |
++ */ |
1992 |
++static inline void deactivate_task(struct task_struct *p, struct rq *rq) |
1993 |
++{ |
1994 |
++ dequeue_task(p, rq, DEQUEUE_SLEEP); |
1995 |
++ p->on_rq = 0; |
1996 |
++ cpufreq_update_util(rq, 0); |
1997 |
++} |
1998 |
++ |
1999 |
++static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) |
2000 |
++{ |
2001 |
++#ifdef CONFIG_SMP |
2002 |
++ /* |
2003 |
++ * After ->cpu is set up to a new value, task_access_lock(p, ...) can be |
2004 |
++ * successfully executed on another CPU. We must ensure that updates of |
2005 |
++ * per-task data have been completed by this moment. |
2006 |
++ */ |
2007 |
++ smp_wmb(); |
2008 |
++ |
2009 |
++ WRITE_ONCE(task_thread_info(p)->cpu, cpu); |
2010 |
++#endif |
2011 |
++} |
2012 |
++ |
2013 |
++static inline bool is_migration_disabled(struct task_struct *p) |
2014 |
++{ |
2015 |
++#ifdef CONFIG_SMP |
2016 |
++ return p->migration_disabled; |
2017 |
++#else |
2018 |
++ return false; |
2019 |
++#endif |
2020 |
++} |
2021 |
++ |
2022 |
++#define SCA_CHECK 0x01 |
2023 |
++#define SCA_USER 0x08 |
2024 |
++ |
2025 |
++#ifdef CONFIG_SMP |
2026 |
++ |
2027 |
++void set_task_cpu(struct task_struct *p, unsigned int new_cpu) |
2028 |
++{ |
2029 |
++#ifdef CONFIG_SCHED_DEBUG |
2030 |
++ unsigned int state = READ_ONCE(p->__state); |
2031 |
++ |
2032 |
++ /* |
2033 |
++ * We should never call set_task_cpu() on a blocked task, |
2034 |
++ * ttwu() will sort out the placement. |
2035 |
++ */ |
2036 |
++ WARN_ON_ONCE(state != TASK_RUNNING && state != TASK_WAKING && !p->on_rq); |
2037 |
++ |
2038 |
++#ifdef CONFIG_LOCKDEP |
2039 |
++ /* |
2040 |
++ * The caller should hold either p->pi_lock or rq->lock, when changing |
2041 |
++ * a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks. |
2042 |
++ * |
2043 |
++ * sched_move_task() holds both and thus holding either pins the cgroup, |
2044 |
++ * see task_group(). |
2045 |
++ */ |
2046 |
++ WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) || |
2047 |
++ lockdep_is_held(&task_rq(p)->lock))); |
2048 |
++#endif |
2049 |
++ /* |
2050 |
++ * Clearly, migrating tasks to offline CPUs is a fairly daft thing. |
2051 |
++ */ |
2052 |
++ WARN_ON_ONCE(!cpu_online(new_cpu)); |
2053 |
++ |
2054 |
++ WARN_ON_ONCE(is_migration_disabled(p)); |
2055 |
++#endif |
2056 |
++ if (task_cpu(p) == new_cpu) |
2057 |
++ return; |
2058 |
++ trace_sched_migrate_task(p, new_cpu); |
2059 |
++ rseq_migrate(p); |
2060 |
++ perf_event_task_migrate(p); |
2061 |
++ |
2062 |
++ __set_task_cpu(p, new_cpu); |
2063 |
++} |
2064 |
++ |
2065 |
++#define MDF_FORCE_ENABLED 0x80 |
2066 |
++ |
2067 |
++static void |
2068 |
++__do_set_cpus_ptr(struct task_struct *p, const struct cpumask *new_mask) |
2069 |
++{ |
2070 |
++ /* |
2071 |
++ * This here violates the locking rules for affinity, since we're only |
2072 |
++ * supposed to change these variables while holding both rq->lock and |
2073 |
++ * p->pi_lock. |
2074 |
++ * |
2075 |
++ * HOWEVER, it magically works, because ttwu() is the only code that |
2076 |
++ * accesses these variables under p->pi_lock and only does so after |
2077 |
++ * smp_cond_load_acquire(&p->on_cpu, !VAL), and we're in __schedule() |
2078 |
++ * before finish_task(). |
2079 |
++ * |
2080 |
++ * XXX do further audits, this smells like something putrid. |
2081 |
++ */ |
2082 |
++ SCHED_WARN_ON(!p->on_cpu); |
2083 |
++ p->cpus_ptr = new_mask; |
2084 |
++} |
2085 |
++ |
2086 |
++void migrate_disable(void) |
2087 |
++{ |
2088 |
++ struct task_struct *p = current; |
2089 |
++ int cpu; |
2090 |
++ |
2091 |
++ if (p->migration_disabled) { |
2092 |
++ p->migration_disabled++; |
2093 |
++ return; |
2094 |
++ } |
2095 |
++ |
2096 |
++ preempt_disable(); |
2097 |
++ cpu = smp_processor_id(); |
2098 |
++ if (cpumask_test_cpu(cpu, &p->cpus_mask)) { |
2099 |
++ cpu_rq(cpu)->nr_pinned++; |
2100 |
++ p->migration_disabled = 1; |
2101 |
++ p->migration_flags &= ~MDF_FORCE_ENABLED; |
2102 |
++ |
2103 |
++ /* |
2104 |
++ * Violates locking rules! see comment in __do_set_cpus_ptr(). |
2105 |
++ */ |
2106 |
++ if (p->cpus_ptr == &p->cpus_mask) |
2107 |
++ __do_set_cpus_ptr(p, cpumask_of(cpu)); |
2108 |
++ } |
2109 |
++ preempt_enable(); |
2110 |
++} |
2111 |
++EXPORT_SYMBOL_GPL(migrate_disable); |
2112 |
++ |
2113 |
++void migrate_enable(void) |
2114 |
++{ |
2115 |
++ struct task_struct *p = current; |
2116 |
++ |
2117 |
++ if (0 == p->migration_disabled) |
2118 |
++ return; |
2119 |
++ |
2120 |
++ if (p->migration_disabled > 1) { |
2121 |
++ p->migration_disabled--; |
2122 |
++ return; |
2123 |
++ } |
2124 |
++ |
2125 |
++ if (WARN_ON_ONCE(!p->migration_disabled)) |
2126 |
++ return; |
2127 |
++ |
2128 |
++ /* |
2129 |
++ * Ensure stop_task runs either before or after this, and that |
2130 |
++ * __set_cpus_allowed_ptr(SCA_MIGRATE_ENABLE) doesn't schedule(). |
2131 |
++ */ |
2132 |
++ preempt_disable(); |
2133 |
++ /* |
2134 |
++ * Assumption: current should be running on allowed cpu |
2135 |
++ */ |
2136 |
++ WARN_ON_ONCE(!cpumask_test_cpu(smp_processor_id(), &p->cpus_mask)); |
2137 |
++ if (p->cpus_ptr != &p->cpus_mask) |
2138 |
++ __do_set_cpus_ptr(p, &p->cpus_mask); |
2139 |
++ /* |
2140 |
++ * Mustn't clear migration_disabled() until cpus_ptr points back at the |
2141 |
++ * regular cpus_mask, otherwise things that race (eg. |
2142 |
++ * select_fallback_rq) get confused. |
2143 |
++ */ |
2144 |
++ barrier(); |
2145 |
++ p->migration_disabled = 0; |
2146 |
++ this_rq()->nr_pinned--; |
2147 |
++ preempt_enable(); |
2148 |
++} |
2149 |
++EXPORT_SYMBOL_GPL(migrate_enable); |
2150 |
++ |
2151 |
++static inline bool rq_has_pinned_tasks(struct rq *rq) |
2152 |
++{ |
2153 |
++ return rq->nr_pinned; |
2154 |
++} |
2155 |
++ |
2156 |
++/* |
2157 |
++ * Per-CPU kthreads are allowed to run on !active && online CPUs, see |
2158 |
++ * __set_cpus_allowed_ptr() and select_fallback_rq(). |
2159 |
++ */ |
2160 |
++static inline bool is_cpu_allowed(struct task_struct *p, int cpu) |
2161 |
++{ |
2162 |
++ /* When not in the task's cpumask, no point in looking further. */ |
2163 |
++ if (!cpumask_test_cpu(cpu, p->cpus_ptr)) |
2164 |
++ return false; |
2165 |
++ |
2166 |
++ /* migrate_disabled() must be allowed to finish. */ |
2167 |
++ if (is_migration_disabled(p)) |
2168 |
++ return cpu_online(cpu); |
2169 |
++ |
2170 |
++ /* Non kernel threads are not allowed during either online or offline. */ |
2171 |
++ if (!(p->flags & PF_KTHREAD)) |
2172 |
++ return cpu_active(cpu) && task_cpu_possible(cpu, p); |
2173 |
++ |
2174 |
++ /* KTHREAD_IS_PER_CPU is always allowed. */ |
2175 |
++ if (kthread_is_per_cpu(p)) |
2176 |
++ return cpu_online(cpu); |
2177 |
++ |
2178 |
++ /* Regular kernel threads don't get to stay during offline. */ |
2179 |
++ if (cpu_dying(cpu)) |
2180 |
++ return false; |
2181 |
++ |
2182 |
++ /* But are allowed during online. */ |
2183 |
++ return cpu_online(cpu); |
2184 |
++} |
2185 |
++ |
2186 |
++/* |
2187 |
++ * This is how migration works: |
2188 |
++ * |
2189 |
++ * 1) we invoke migration_cpu_stop() on the target CPU using |
2190 |
++ * stop_one_cpu(). |
2191 |
++ * 2) stopper starts to run (implicitly forcing the migrated thread |
2192 |
++ * off the CPU) |
2193 |
++ * 3) it checks whether the migrated task is still in the wrong runqueue. |
2194 |
++ * 4) if it's in the wrong runqueue then the migration thread removes |
2195 |
++ * it and puts it into the right queue. |
2196 |
++ * 5) stopper completes and stop_one_cpu() returns and the migration |
2197 |
++ * is done. |
2198 |
++ */ |
2199 |
++ |
2200 |
++/* |
2201 |
++ * move_queued_task - move a queued task to new rq. |
2202 |
++ * |
2203 |
++ * Returns (locked) new rq. Old rq's lock is released. |
2204 |
++ */ |
2205 |
++static struct rq *move_queued_task(struct rq *rq, struct task_struct *p, int |
2206 |
++ new_cpu) |
2207 |
++{ |
2208 |
++ lockdep_assert_held(&rq->lock); |
2209 |
++ |
2210 |
++ WRITE_ONCE(p->on_rq, TASK_ON_RQ_MIGRATING); |
2211 |
++ dequeue_task(p, rq, 0); |
2212 |
++ update_sched_rq_watermark(rq); |
2213 |
++ set_task_cpu(p, new_cpu); |
2214 |
++ raw_spin_unlock(&rq->lock); |
2215 |
++ |
2216 |
++ rq = cpu_rq(new_cpu); |
2217 |
++ |
2218 |
++ raw_spin_lock(&rq->lock); |
2219 |
++ BUG_ON(task_cpu(p) != new_cpu); |
2220 |
++ sched_task_sanity_check(p, rq); |
2221 |
++ enqueue_task(p, rq, 0); |
2222 |
++ p->on_rq = TASK_ON_RQ_QUEUED; |
2223 |
++ check_preempt_curr(rq); |
2224 |
++ |
2225 |
++ return rq; |
2226 |
++} |
2227 |
++ |
2228 |
++struct migration_arg { |
2229 |
++ struct task_struct *task; |
2230 |
++ int dest_cpu; |
2231 |
++}; |
2232 |
++ |
2233 |
++/* |
2234 |
++ * Move (not current) task off this CPU, onto the destination CPU. We're doing |
2235 |
++ * this because either it can't run here any more (set_cpus_allowed() |
2236 |
++ * away from this CPU, or CPU going down), or because we're |
2237 |
++ * attempting to rebalance this task on exec (sched_exec). |
2238 |
++ * |
2239 |
++ * So we race with normal scheduler movements, but that's OK, as long |
2240 |
++ * as the task is no longer on this CPU. |
2241 |
++ */ |
2242 |
++static struct rq *__migrate_task(struct rq *rq, struct task_struct *p, int |
2243 |
++ dest_cpu) |
2244 |
++{ |
2245 |
++ /* Affinity changed (again). */ |
2246 |
++ if (!is_cpu_allowed(p, dest_cpu)) |
2247 |
++ return rq; |
2248 |
++ |
2249 |
++ update_rq_clock(rq); |
2250 |
++ return move_queued_task(rq, p, dest_cpu); |
2251 |
++} |
2252 |
++ |
2253 |
++/* |
2254 |
++ * migration_cpu_stop - this will be executed by a highprio stopper thread |
2255 |
++ * and performs thread migration by bumping thread off CPU then |
2256 |
++ * 'pushing' onto another runqueue. |
2257 |
++ */ |
2258 |
++static int migration_cpu_stop(void *data) |
2259 |
++{ |
2260 |
++ struct migration_arg *arg = data; |
2261 |
++ struct task_struct *p = arg->task; |
2262 |
++ struct rq *rq = this_rq(); |
2263 |
++ unsigned long flags; |
2264 |
++ |
2265 |
++ /* |
2266 |
++ * The original target CPU might have gone down and we might |
2267 |
++ * be on another CPU but it doesn't matter. |
2268 |
++ */ |
2269 |
++ local_irq_save(flags); |
2270 |
++ /* |
2271 |
++ * We need to explicitly wake pending tasks before running |
2272 |
++ * __migrate_task() such that we will not miss enforcing cpus_ptr |
2273 |
++ * during wakeups, see set_cpus_allowed_ptr()'s TASK_WAKING test. |
2274 |
++ */ |
2275 |
++ flush_smp_call_function_queue(); |
2276 |
++ |
2277 |
++ raw_spin_lock(&p->pi_lock); |
2278 |
++ raw_spin_lock(&rq->lock); |
2279 |
++ /* |
2280 |
++ * If task_rq(p) != rq, it cannot be migrated here, because we're |
2281 |
++ * holding rq->lock, if p->on_rq == 0 it cannot get enqueued because |
2282 |
++ * we're holding p->pi_lock. |
2283 |
++ */ |
2284 |
++ if (task_rq(p) == rq && task_on_rq_queued(p)) |
2285 |
++ rq = __migrate_task(rq, p, arg->dest_cpu); |
2286 |
++ raw_spin_unlock(&rq->lock); |
2287 |
++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
2288 |
++ |
2289 |
++ return 0; |
2290 |
++} |
2291 |
++ |
2292 |
++static inline void |
2293 |
++set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask) |
2294 |
++{ |
2295 |
++ cpumask_copy(&p->cpus_mask, new_mask); |
2296 |
++ p->nr_cpus_allowed = cpumask_weight(new_mask); |
2297 |
++} |
2298 |
++ |
2299 |
++static void |
2300 |
++__do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) |
2301 |
++{ |
2302 |
++ lockdep_assert_held(&p->pi_lock); |
2303 |
++ set_cpus_allowed_common(p, new_mask); |
2304 |
++} |
2305 |
++ |
2306 |
++void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) |
2307 |
++{ |
2308 |
++ __do_set_cpus_allowed(p, new_mask); |
2309 |
++} |
2310 |
++ |
2311 |
++int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, |
2312 |
++ int node) |
2313 |
++{ |
2314 |
++ if (!src->user_cpus_ptr) |
2315 |
++ return 0; |
2316 |
++ |
2317 |
++ dst->user_cpus_ptr = kmalloc_node(cpumask_size(), GFP_KERNEL, node); |
2318 |
++ if (!dst->user_cpus_ptr) |
2319 |
++ return -ENOMEM; |
2320 |
++ |
2321 |
++ cpumask_copy(dst->user_cpus_ptr, src->user_cpus_ptr); |
2322 |
++ return 0; |
2323 |
++} |
2324 |
++ |
2325 |
++static inline struct cpumask *clear_user_cpus_ptr(struct task_struct *p) |
2326 |
++{ |
2327 |
++ struct cpumask *user_mask = NULL; |
2328 |
++ |
2329 |
++ swap(p->user_cpus_ptr, user_mask); |
2330 |
++ |
2331 |
++ return user_mask; |
2332 |
++} |
2333 |
++ |
2334 |
++void release_user_cpus_ptr(struct task_struct *p) |
2335 |
++{ |
2336 |
++ kfree(clear_user_cpus_ptr(p)); |
2337 |
++} |
2338 |
++ |
2339 |
++#endif |
2340 |
++ |
2341 |
++/** |
2342 |
++ * task_curr - is this task currently executing on a CPU? |
2343 |
++ * @p: the task in question. |
2344 |
++ * |
2345 |
++ * Return: 1 if the task is currently executing. 0 otherwise. |
2346 |
++ */ |
2347 |
++inline int task_curr(const struct task_struct *p) |
2348 |
++{ |
2349 |
++ return cpu_curr(task_cpu(p)) == p; |
2350 |
++} |
2351 |
++ |
2352 |
++#ifdef CONFIG_SMP |
2353 |
++/* |
2354 |
++ * wait_task_inactive - wait for a thread to unschedule. |
2355 |
++ * |
2356 |
++ * If @match_state is nonzero, it's the @p->state value just checked and |
2357 |
++ * not expected to change. If it changes, i.e. @p might have woken up, |
2358 |
++ * then return zero. When we succeed in waiting for @p to be off its CPU, |
2359 |
++ * we return a positive number (its total switch count). If a second call |
2360 |
++ * a short while later returns the same number, the caller can be sure that |
2361 |
++ * @p has remained unscheduled the whole time. |
2362 |
++ * |
2363 |
++ * The caller must ensure that the task *will* unschedule sometime soon, |
2364 |
++ * else this function might spin for a *long* time. This function can't |
2365 |
++ * be called with interrupts off, or it may introduce deadlock with |
2366 |
++ * smp_call_function() if an IPI is sent by the same process we are |
2367 |
++ * waiting to become inactive. |
2368 |
++ */ |
2369 |
++unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state) |
2370 |
++{ |
2371 |
++ unsigned long flags; |
2372 |
++ bool running, on_rq; |
2373 |
++ unsigned long ncsw; |
2374 |
++ struct rq *rq; |
2375 |
++ raw_spinlock_t *lock; |
2376 |
++ |
2377 |
++ for (;;) { |
2378 |
++ rq = task_rq(p); |
2379 |
++ |
2380 |
++ /* |
2381 |
++ * If the task is actively running on another CPU |
2382 |
++ * still, just relax and busy-wait without holding |
2383 |
++ * any locks. |
2384 |
++ * |
2385 |
++ * NOTE! Since we don't hold any locks, it's not |
2386 |
++ * even sure that "rq" stays as the right runqueue! |
2387 |
++ * But we don't care, since this will return false |
2388 |
++ * if the runqueue has changed and p is actually now |
2389 |
++ * running somewhere else! |
2390 |
++ */ |
2391 |
++ while (task_running(p) && p == rq->curr) { |
2392 |
++ if (match_state && unlikely(READ_ONCE(p->__state) != match_state)) |
2393 |
++ return 0; |
2394 |
++ cpu_relax(); |
2395 |
++ } |
2396 |
++ |
2397 |
++ /* |
2398 |
++ * Ok, time to look more closely! We need the rq |
2399 |
++ * lock now, to be *sure*. If we're wrong, we'll |
2400 |
++ * just go back and repeat. |
2401 |
++ */ |
2402 |
++ task_access_lock_irqsave(p, &lock, &flags); |
2403 |
++ trace_sched_wait_task(p); |
2404 |
++ running = task_running(p); |
2405 |
++ on_rq = p->on_rq; |
2406 |
++ ncsw = 0; |
2407 |
++ if (!match_state || READ_ONCE(p->__state) == match_state) |
2408 |
++ ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ |
2409 |
++ task_access_unlock_irqrestore(p, lock, &flags); |
2410 |
++ |
2411 |
++ /* |
2412 |
++ * If it changed from the expected state, bail out now. |
2413 |
++ */ |
2414 |
++ if (unlikely(!ncsw)) |
2415 |
++ break; |
2416 |
++ |
2417 |
++ /* |
2418 |
++ * Was it really running after all now that we |
2419 |
++ * checked with the proper locks actually held? |
2420 |
++ * |
2421 |
++ * Oops. Go back and try again.. |
2422 |
++ */ |
2423 |
++ if (unlikely(running)) { |
2424 |
++ cpu_relax(); |
2425 |
++ continue; |
2426 |
++ } |
2427 |
++ |
2428 |
++ /* |
2429 |
++ * It's not enough that it's not actively running, |
2430 |
++ * it must be off the runqueue _entirely_, and not |
2431 |
++ * preempted! |
2432 |
++ * |
2433 |
++ * So if it was still runnable (but just not actively |
2434 |
++ * running right now), it's preempted, and we should |
2435 |
++ * yield - it could be a while. |
2436 |
++ */ |
2437 |
++ if (unlikely(on_rq)) { |
2438 |
++ ktime_t to = NSEC_PER_SEC / HZ; |
2439 |
++ |
2440 |
++ set_current_state(TASK_UNINTERRUPTIBLE); |
2441 |
++ schedule_hrtimeout(&to, HRTIMER_MODE_REL_HARD); |
2442 |
++ continue; |
2443 |
++ } |
2444 |
++ |
2445 |
++ /* |
2446 |
++ * Ahh, all good. It wasn't running, and it wasn't |
2447 |
++ * runnable, which means that it will never become |
2448 |
++ * running in the future either. We're all done! |
2449 |
++ */ |
2450 |
++ break; |
2451 |
++ } |
2452 |
++ |
2453 |
++ return ncsw; |
2454 |
++} |
2455 |
++ |
2456 |
++/*** |
2457 |
++ * kick_process - kick a running thread to enter/exit the kernel |
2458 |
++ * @p: the to-be-kicked thread |
2459 |
++ * |
2460 |
++ * Cause a process which is running on another CPU to enter |
2461 |
++ * kernel-mode, without any delay. (to get signals handled.) |
2462 |
++ * |
2463 |
++ * NOTE: this function doesn't have to take the runqueue lock, |
2464 |
++ * because all it wants to ensure is that the remote task enters |
2465 |
++ * the kernel. If the IPI races and the task has been migrated |
2466 |
++ * to another CPU then no harm is done and the purpose has been |
2467 |
++ * achieved as well. |
2468 |
++ */ |
2469 |
++void kick_process(struct task_struct *p) |
2470 |
++{ |
2471 |
++ int cpu; |
2472 |
++ |
2473 |
++ preempt_disable(); |
2474 |
++ cpu = task_cpu(p); |
2475 |
++ if ((cpu != smp_processor_id()) && task_curr(p)) |
2476 |
++ smp_send_reschedule(cpu); |
2477 |
++ preempt_enable(); |
2478 |
++} |
2479 |
++EXPORT_SYMBOL_GPL(kick_process); |
2480 |
++ |
2481 |
++/* |
2482 |
++ * ->cpus_ptr is protected by both rq->lock and p->pi_lock |
2483 |
++ * |
2484 |
++ * A few notes on cpu_active vs cpu_online: |
2485 |
++ * |
2486 |
++ * - cpu_active must be a subset of cpu_online |
2487 |
++ * |
2488 |
++ * - on CPU-up we allow per-CPU kthreads on the online && !active CPU, |
2489 |
++ * see __set_cpus_allowed_ptr(). At this point the newly online |
2490 |
++ * CPU isn't yet part of the sched domains, and balancing will not |
2491 |
++ * see it. |
2492 |
++ * |
2493 |
++ * - on cpu-down we clear cpu_active() to mask the sched domains and |
2494 |
++ * avoid the load balancer to place new tasks on the to be removed |
2495 |
++ * CPU. Existing tasks will remain running there and will be taken |
2496 |
++ * off. |
2497 |
++ * |
2498 |
++ * This means that fallback selection must not select !active CPUs. |
2499 |
++ * And can assume that any active CPU must be online. Conversely |
2500 |
++ * select_task_rq() below may allow selection of !active CPUs in order |
2501 |
++ * to satisfy the above rules. |
2502 |
++ */ |
2503 |
++static int select_fallback_rq(int cpu, struct task_struct *p) |
2504 |
++{ |
2505 |
++ int nid = cpu_to_node(cpu); |
2506 |
++ const struct cpumask *nodemask = NULL; |
2507 |
++ enum { cpuset, possible, fail } state = cpuset; |
2508 |
++ int dest_cpu; |
2509 |
++ |
2510 |
++ /* |
2511 |
++ * If the node that the CPU is on has been offlined, cpu_to_node() |
2512 |
++ * will return -1. There is no CPU on the node, and we should |
2513 |
++ * select the CPU on the other node. |
2514 |
++ */ |
2515 |
++ if (nid != -1) { |
2516 |
++ nodemask = cpumask_of_node(nid); |
2517 |
++ |
2518 |
++ /* Look for allowed, online CPU in same node. */ |
2519 |
++ for_each_cpu(dest_cpu, nodemask) { |
2520 |
++ if (is_cpu_allowed(p, dest_cpu)) |
2521 |
++ return dest_cpu; |
2522 |
++ } |
2523 |
++ } |
2524 |
++ |
2525 |
++ for (;;) { |
2526 |
++ /* Any allowed, online CPU? */ |
2527 |
++ for_each_cpu(dest_cpu, p->cpus_ptr) { |
2528 |
++ if (!is_cpu_allowed(p, dest_cpu)) |
2529 |
++ continue; |
2530 |
++ goto out; |
2531 |
++ } |
2532 |
++ |
2533 |
++ /* No more Mr. Nice Guy. */ |
2534 |
++ switch (state) { |
2535 |
++ case cpuset: |
2536 |
++ if (cpuset_cpus_allowed_fallback(p)) { |
2537 |
++ state = possible; |
2538 |
++ break; |
2539 |
++ } |
2540 |
++ fallthrough; |
2541 |
++ case possible: |
2542 |
++ /* |
2543 |
++ * XXX When called from select_task_rq() we only |
2544 |
++ * hold p->pi_lock and again violate locking order. |
2545 |
++ * |
2546 |
++ * More yuck to audit. |
2547 |
++ */ |
2548 |
++ do_set_cpus_allowed(p, task_cpu_possible_mask(p)); |
2549 |
++ state = fail; |
2550 |
++ break; |
2551 |
++ |
2552 |
++ case fail: |
2553 |
++ BUG(); |
2554 |
++ break; |
2555 |
++ } |
2556 |
++ } |
2557 |
++ |
2558 |
++out: |
2559 |
++ if (state != cpuset) { |
2560 |
++ /* |
2561 |
++ * Don't tell them about moving exiting tasks or |
2562 |
++ * kernel threads (both mm NULL), since they never |
2563 |
++ * leave kernel. |
2564 |
++ */ |
2565 |
++ if (p->mm && printk_ratelimit()) { |
2566 |
++ printk_deferred("process %d (%s) no longer affine to cpu%d\n", |
2567 |
++ task_pid_nr(p), p->comm, cpu); |
2568 |
++ } |
2569 |
++ } |
2570 |
++ |
2571 |
++ return dest_cpu; |
2572 |
++} |
2573 |
++ |
2574 |
++static inline int select_task_rq(struct task_struct *p) |
2575 |
++{ |
2576 |
++ cpumask_t chk_mask, tmp; |
2577 |
++ |
2578 |
++ if (unlikely(!cpumask_and(&chk_mask, p->cpus_ptr, cpu_active_mask))) |
2579 |
++ return select_fallback_rq(task_cpu(p), p); |
2580 |
++ |
2581 |
++ if ( |
2582 |
++#ifdef CONFIG_SCHED_SMT |
2583 |
++ cpumask_and(&tmp, &chk_mask, &sched_sg_idle_mask) || |
2584 |
++#endif |
2585 |
++ cpumask_and(&tmp, &chk_mask, sched_rq_watermark) || |
2586 |
++ cpumask_and(&tmp, &chk_mask, |
2587 |
++ sched_rq_watermark + SCHED_QUEUE_BITS - 1 - task_sched_prio(p))) |
2588 |
++ return best_mask_cpu(task_cpu(p), &tmp); |
2589 |
++ |
2590 |
++ return best_mask_cpu(task_cpu(p), &chk_mask); |
2591 |
++} |
2592 |
++ |
2593 |
++void sched_set_stop_task(int cpu, struct task_struct *stop) |
2594 |
++{ |
2595 |
++ static struct lock_class_key stop_pi_lock; |
2596 |
++ struct sched_param stop_param = { .sched_priority = STOP_PRIO }; |
2597 |
++ struct sched_param start_param = { .sched_priority = 0 }; |
2598 |
++ struct task_struct *old_stop = cpu_rq(cpu)->stop; |
2599 |
++ |
2600 |
++ if (stop) { |
2601 |
++ /* |
2602 |
++ * Make it appear like a SCHED_FIFO task, its something |
2603 |
++ * userspace knows about and won't get confused about. |
2604 |
++ * |
2605 |
++ * Also, it will make PI more or less work without too |
2606 |
++ * much confusion -- but then, stop work should not |
2607 |
++ * rely on PI working anyway. |
2608 |
++ */ |
2609 |
++ sched_setscheduler_nocheck(stop, SCHED_FIFO, &stop_param); |
2610 |
++ |
2611 |
++ /* |
2612 |
++ * The PI code calls rt_mutex_setprio() with ->pi_lock held to |
2613 |
++ * adjust the effective priority of a task. As a result, |
2614 |
++ * rt_mutex_setprio() can trigger (RT) balancing operations, |
2615 |
++ * which can then trigger wakeups of the stop thread to push |
2616 |
++ * around the current task. |
2617 |
++ * |
2618 |
++ * The stop task itself will never be part of the PI-chain, it |
2619 |
++ * never blocks, therefore that ->pi_lock recursion is safe. |
2620 |
++ * Tell lockdep about this by placing the stop->pi_lock in its |
2621 |
++ * own class. |
2622 |
++ */ |
2623 |
++ lockdep_set_class(&stop->pi_lock, &stop_pi_lock); |
2624 |
++ } |
2625 |
++ |
2626 |
++ cpu_rq(cpu)->stop = stop; |
2627 |
++ |
2628 |
++ if (old_stop) { |
2629 |
++ /* |
2630 |
++ * Reset it back to a normal scheduling policy so that |
2631 |
++ * it can die in pieces. |
2632 |
++ */ |
2633 |
++ sched_setscheduler_nocheck(old_stop, SCHED_NORMAL, &start_param); |
2634 |
++ } |
2635 |
++} |
2636 |
++ |
2637 |
++static int affine_move_task(struct rq *rq, struct task_struct *p, int dest_cpu, |
2638 |
++ raw_spinlock_t *lock, unsigned long irq_flags) |
2639 |
++{ |
2640 |
++ /* Can the task run on the task's current CPU? If so, we're done */ |
2641 |
++ if (!cpumask_test_cpu(task_cpu(p), &p->cpus_mask)) { |
2642 |
++ if (p->migration_disabled) { |
2643 |
++ if (likely(p->cpus_ptr != &p->cpus_mask)) |
2644 |
++ __do_set_cpus_ptr(p, &p->cpus_mask); |
2645 |
++ p->migration_disabled = 0; |
2646 |
++ p->migration_flags |= MDF_FORCE_ENABLED; |
2647 |
++ /* When p is migrate_disabled, rq->lock should be held */ |
2648 |
++ rq->nr_pinned--; |
2649 |
++ } |
2650 |
++ |
2651 |
++ if (task_running(p) || READ_ONCE(p->__state) == TASK_WAKING) { |
2652 |
++ struct migration_arg arg = { p, dest_cpu }; |
2653 |
++ |
2654 |
++ /* Need help from migration thread: drop lock and wait. */ |
2655 |
++ __task_access_unlock(p, lock); |
2656 |
++ raw_spin_unlock_irqrestore(&p->pi_lock, irq_flags); |
2657 |
++ stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); |
2658 |
++ return 0; |
2659 |
++ } |
2660 |
++ if (task_on_rq_queued(p)) { |
2661 |
++ /* |
2662 |
++ * OK, since we're going to drop the lock immediately |
2663 |
++ * afterwards anyway. |
2664 |
++ */ |
2665 |
++ update_rq_clock(rq); |
2666 |
++ rq = move_queued_task(rq, p, dest_cpu); |
2667 |
++ lock = &rq->lock; |
2668 |
++ } |
2669 |
++ } |
2670 |
++ __task_access_unlock(p, lock); |
2671 |
++ raw_spin_unlock_irqrestore(&p->pi_lock, irq_flags); |
2672 |
++ return 0; |
2673 |
++} |
2674 |
++ |
2675 |
++static int __set_cpus_allowed_ptr_locked(struct task_struct *p, |
2676 |
++ const struct cpumask *new_mask, |
2677 |
++ u32 flags, |
2678 |
++ struct rq *rq, |
2679 |
++ raw_spinlock_t *lock, |
2680 |
++ unsigned long irq_flags) |
2681 |
++{ |
2682 |
++ const struct cpumask *cpu_allowed_mask = task_cpu_possible_mask(p); |
2683 |
++ const struct cpumask *cpu_valid_mask = cpu_active_mask; |
2684 |
++ bool kthread = p->flags & PF_KTHREAD; |
2685 |
++ struct cpumask *user_mask = NULL; |
2686 |
++ int dest_cpu; |
2687 |
++ int ret = 0; |
2688 |
++ |
2689 |
++ if (kthread || is_migration_disabled(p)) { |
2690 |
++ /* |
2691 |
++ * Kernel threads are allowed on online && !active CPUs, |
2692 |
++ * however, during cpu-hot-unplug, even these might get pushed |
2693 |
++ * away if not KTHREAD_IS_PER_CPU. |
2694 |
++ * |
2695 |
++ * Specifically, migration_disabled() tasks must not fail the |
2696 |
++ * cpumask_any_and_distribute() pick below, esp. so on |
2697 |
++ * SCA_MIGRATE_ENABLE, otherwise we'll not call |
2698 |
++ * set_cpus_allowed_common() and actually reset p->cpus_ptr. |
2699 |
++ */ |
2700 |
++ cpu_valid_mask = cpu_online_mask; |
2701 |
++ } |
2702 |
++ |
2703 |
++ if (!kthread && !cpumask_subset(new_mask, cpu_allowed_mask)) { |
2704 |
++ ret = -EINVAL; |
2705 |
++ goto out; |
2706 |
++ } |
2707 |
++ |
2708 |
++ /* |
2709 |
++ * Must re-check here, to close a race against __kthread_bind(), |
2710 |
++ * sched_setaffinity() is not guaranteed to observe the flag. |
2711 |
++ */ |
2712 |
++ if ((flags & SCA_CHECK) && (p->flags & PF_NO_SETAFFINITY)) { |
2713 |
++ ret = -EINVAL; |
2714 |
++ goto out; |
2715 |
++ } |
2716 |
++ |
2717 |
++ if (cpumask_equal(&p->cpus_mask, new_mask)) |
2718 |
++ goto out; |
2719 |
++ |
2720 |
++ dest_cpu = cpumask_any_and(cpu_valid_mask, new_mask); |
2721 |
++ if (dest_cpu >= nr_cpu_ids) { |
2722 |
++ ret = -EINVAL; |
2723 |
++ goto out; |
2724 |
++ } |
2725 |
++ |
2726 |
++ __do_set_cpus_allowed(p, new_mask); |
2727 |
++ |
2728 |
++ if (flags & SCA_USER) |
2729 |
++ user_mask = clear_user_cpus_ptr(p); |
2730 |
++ |
2731 |
++ ret = affine_move_task(rq, p, dest_cpu, lock, irq_flags); |
2732 |
++ |
2733 |
++ kfree(user_mask); |
2734 |
++ |
2735 |
++ return ret; |
2736 |
++ |
2737 |
++out: |
2738 |
++ __task_access_unlock(p, lock); |
2739 |
++ raw_spin_unlock_irqrestore(&p->pi_lock, irq_flags); |
2740 |
++ |
2741 |
++ return ret; |
2742 |
++} |
2743 |
++ |
2744 |
++/* |
2745 |
++ * Change a given task's CPU affinity. Migrate the thread to a |
2746 |
++ * proper CPU and schedule it away if the CPU it's executing on |
2747 |
++ * is removed from the allowed bitmask. |
2748 |
++ * |
2749 |
++ * NOTE: the caller must have a valid reference to the task, the |
2750 |
++ * task must not exit() & deallocate itself prematurely. The |
2751 |
++ * call is not atomic; no spinlocks may be held. |
2752 |
++ */ |
2753 |
++static int __set_cpus_allowed_ptr(struct task_struct *p, |
2754 |
++ const struct cpumask *new_mask, u32 flags) |
2755 |
++{ |
2756 |
++ unsigned long irq_flags; |
2757 |
++ struct rq *rq; |
2758 |
++ raw_spinlock_t *lock; |
2759 |
++ |
2760 |
++ raw_spin_lock_irqsave(&p->pi_lock, irq_flags); |
2761 |
++ rq = __task_access_lock(p, &lock); |
2762 |
++ |
2763 |
++ return __set_cpus_allowed_ptr_locked(p, new_mask, flags, rq, lock, irq_flags); |
2764 |
++} |
2765 |
++ |
2766 |
++int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) |
2767 |
++{ |
2768 |
++ return __set_cpus_allowed_ptr(p, new_mask, 0); |
2769 |
++} |
2770 |
++EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); |
2771 |
++ |
2772 |
++/* |
2773 |
++ * Change a given task's CPU affinity to the intersection of its current |
2774 |
++ * affinity mask and @subset_mask, writing the resulting mask to @new_mask |
2775 |
++ * and pointing @p->user_cpus_ptr to a copy of the old mask. |
2776 |
++ * If the resulting mask is empty, leave the affinity unchanged and return |
2777 |
++ * -EINVAL. |
2778 |
++ */ |
2779 |
++static int restrict_cpus_allowed_ptr(struct task_struct *p, |
2780 |
++ struct cpumask *new_mask, |
2781 |
++ const struct cpumask *subset_mask) |
2782 |
++{ |
2783 |
++ struct cpumask *user_mask = NULL; |
2784 |
++ unsigned long irq_flags; |
2785 |
++ raw_spinlock_t *lock; |
2786 |
++ struct rq *rq; |
2787 |
++ int err; |
2788 |
++ |
2789 |
++ if (!p->user_cpus_ptr) { |
2790 |
++ user_mask = kmalloc(cpumask_size(), GFP_KERNEL); |
2791 |
++ if (!user_mask) |
2792 |
++ return -ENOMEM; |
2793 |
++ } |
2794 |
++ |
2795 |
++ raw_spin_lock_irqsave(&p->pi_lock, irq_flags); |
2796 |
++ rq = __task_access_lock(p, &lock); |
2797 |
++ |
2798 |
++ if (!cpumask_and(new_mask, &p->cpus_mask, subset_mask)) { |
2799 |
++ err = -EINVAL; |
2800 |
++ goto err_unlock; |
2801 |
++ } |
2802 |
++ |
2803 |
++ /* |
2804 |
++ * We're about to butcher the task affinity, so keep track of what |
2805 |
++ * the user asked for in case we're able to restore it later on. |
2806 |
++ */ |
2807 |
++ if (user_mask) { |
2808 |
++ cpumask_copy(user_mask, p->cpus_ptr); |
2809 |
++ p->user_cpus_ptr = user_mask; |
2810 |
++ } |
2811 |
++ |
2812 |
++ /*return __set_cpus_allowed_ptr_locked(p, new_mask, 0, rq, &rf);*/ |
2813 |
++ return __set_cpus_allowed_ptr_locked(p, new_mask, 0, rq, lock, irq_flags); |
2814 |
++ |
2815 |
++err_unlock: |
2816 |
++ __task_access_unlock(p, lock); |
2817 |
++ raw_spin_unlock_irqrestore(&p->pi_lock, irq_flags); |
2818 |
++ kfree(user_mask); |
2819 |
++ return err; |
2820 |
++} |
2821 |
++ |
2822 |
++/* |
2823 |
++ * Restrict the CPU affinity of task @p so that it is a subset of |
2824 |
++ * task_cpu_possible_mask() and point @p->user_cpu_ptr to a copy of the |
2825 |
++ * old affinity mask. If the resulting mask is empty, we warn and walk |
2826 |
++ * up the cpuset hierarchy until we find a suitable mask. |
2827 |
++ */ |
2828 |
++void force_compatible_cpus_allowed_ptr(struct task_struct *p) |
2829 |
++{ |
2830 |
++ cpumask_var_t new_mask; |
2831 |
++ const struct cpumask *override_mask = task_cpu_possible_mask(p); |
2832 |
++ |
2833 |
++ alloc_cpumask_var(&new_mask, GFP_KERNEL); |
2834 |
++ |
2835 |
++ /* |
2836 |
++ * __migrate_task() can fail silently in the face of concurrent |
2837 |
++ * offlining of the chosen destination CPU, so take the hotplug |
2838 |
++ * lock to ensure that the migration succeeds. |
2839 |
++ */ |
2840 |
++ cpus_read_lock(); |
2841 |
++ if (!cpumask_available(new_mask)) |
2842 |
++ goto out_set_mask; |
2843 |
++ |
2844 |
++ if (!restrict_cpus_allowed_ptr(p, new_mask, override_mask)) |
2845 |
++ goto out_free_mask; |
2846 |
++ |
2847 |
++ /* |
2848 |
++ * We failed to find a valid subset of the affinity mask for the |
2849 |
++ * task, so override it based on its cpuset hierarchy. |
2850 |
++ */ |
2851 |
++ cpuset_cpus_allowed(p, new_mask); |
2852 |
++ override_mask = new_mask; |
2853 |
++ |
2854 |
++out_set_mask: |
2855 |
++ if (printk_ratelimit()) { |
2856 |
++ printk_deferred("Overriding affinity for process %d (%s) to CPUs %*pbl\n", |
2857 |
++ task_pid_nr(p), p->comm, |
2858 |
++ cpumask_pr_args(override_mask)); |
2859 |
++ } |
2860 |
++ |
2861 |
++ WARN_ON(set_cpus_allowed_ptr(p, override_mask)); |
2862 |
++out_free_mask: |
2863 |
++ cpus_read_unlock(); |
2864 |
++ free_cpumask_var(new_mask); |
2865 |
++} |
2866 |
++ |
2867 |
++static int |
2868 |
++__sched_setaffinity(struct task_struct *p, const struct cpumask *mask); |
2869 |
++ |
2870 |
++/* |
2871 |
++ * Restore the affinity of a task @p which was previously restricted by a |
2872 |
++ * call to force_compatible_cpus_allowed_ptr(). This will clear (and free) |
2873 |
++ * @p->user_cpus_ptr. |
2874 |
++ * |
2875 |
++ * It is the caller's responsibility to serialise this with any calls to |
2876 |
++ * force_compatible_cpus_allowed_ptr(@p). |
2877 |
++ */ |
2878 |
++void relax_compatible_cpus_allowed_ptr(struct task_struct *p) |
2879 |
++{ |
2880 |
++ struct cpumask *user_mask = p->user_cpus_ptr; |
2881 |
++ unsigned long flags; |
2882 |
++ |
2883 |
++ /* |
2884 |
++ * Try to restore the old affinity mask. If this fails, then |
2885 |
++ * we free the mask explicitly to avoid it being inherited across |
2886 |
++ * a subsequent fork(). |
2887 |
++ */ |
2888 |
++ if (!user_mask || !__sched_setaffinity(p, user_mask)) |
2889 |
++ return; |
2890 |
++ |
2891 |
++ raw_spin_lock_irqsave(&p->pi_lock, flags); |
2892 |
++ user_mask = clear_user_cpus_ptr(p); |
2893 |
++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
2894 |
++ |
2895 |
++ kfree(user_mask); |
2896 |
++} |
2897 |
++ |
2898 |
++#else /* CONFIG_SMP */ |
2899 |
++ |
2900 |
++static inline int select_task_rq(struct task_struct *p) |
2901 |
++{ |
2902 |
++ return 0; |
2903 |
++} |
2904 |
++ |
2905 |
++static inline int |
2906 |
++__set_cpus_allowed_ptr(struct task_struct *p, |
2907 |
++ const struct cpumask *new_mask, u32 flags) |
2908 |
++{ |
2909 |
++ return set_cpus_allowed_ptr(p, new_mask); |
2910 |
++} |
2911 |
++ |
2912 |
++static inline bool rq_has_pinned_tasks(struct rq *rq) |
2913 |
++{ |
2914 |
++ return false; |
2915 |
++} |
2916 |
++ |
2917 |
++#endif /* !CONFIG_SMP */ |
2918 |
++ |
2919 |
++static void |
2920 |
++ttwu_stat(struct task_struct *p, int cpu, int wake_flags) |
2921 |
++{ |
2922 |
++ struct rq *rq; |
2923 |
++ |
2924 |
++ if (!schedstat_enabled()) |
2925 |
++ return; |
2926 |
++ |
2927 |
++ rq = this_rq(); |
2928 |
++ |
2929 |
++#ifdef CONFIG_SMP |
2930 |
++ if (cpu == rq->cpu) { |
2931 |
++ __schedstat_inc(rq->ttwu_local); |
2932 |
++ __schedstat_inc(p->stats.nr_wakeups_local); |
2933 |
++ } else { |
2934 |
++ /** Alt schedule FW ToDo: |
2935 |
++ * How to do ttwu_wake_remote |
2936 |
++ */ |
2937 |
++ } |
2938 |
++#endif /* CONFIG_SMP */ |
2939 |
++ |
2940 |
++ __schedstat_inc(rq->ttwu_count); |
2941 |
++ __schedstat_inc(p->stats.nr_wakeups); |
2942 |
++} |
2943 |
++ |
2944 |
++/* |
2945 |
++ * Mark the task runnable and perform wakeup-preemption. |
2946 |
++ */ |
2947 |
++static inline void |
2948 |
++ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) |
2949 |
++{ |
2950 |
++ check_preempt_curr(rq); |
2951 |
++ WRITE_ONCE(p->__state, TASK_RUNNING); |
2952 |
++ trace_sched_wakeup(p); |
2953 |
++} |
2954 |
++ |
2955 |
++static inline void |
2956 |
++ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags) |
2957 |
++{ |
2958 |
++ if (p->sched_contributes_to_load) |
2959 |
++ rq->nr_uninterruptible--; |
2960 |
++ |
2961 |
++ if ( |
2962 |
++#ifdef CONFIG_SMP |
2963 |
++ !(wake_flags & WF_MIGRATED) && |
2964 |
++#endif |
2965 |
++ p->in_iowait) { |
2966 |
++ delayacct_blkio_end(p); |
2967 |
++ atomic_dec(&task_rq(p)->nr_iowait); |
2968 |
++ } |
2969 |
++ |
2970 |
++ activate_task(p, rq); |
2971 |
++ ttwu_do_wakeup(rq, p, 0); |
2972 |
++} |
2973 |
++ |
2974 |
++/* |
2975 |
++ * Consider @p being inside a wait loop: |
2976 |
++ * |
2977 |
++ * for (;;) { |
2978 |
++ * set_current_state(TASK_UNINTERRUPTIBLE); |
2979 |
++ * |
2980 |
++ * if (CONDITION) |
2981 |
++ * break; |
2982 |
++ * |
2983 |
++ * schedule(); |
2984 |
++ * } |
2985 |
++ * __set_current_state(TASK_RUNNING); |
2986 |
++ * |
2987 |
++ * between set_current_state() and schedule(). In this case @p is still |
2988 |
++ * runnable, so all that needs doing is change p->state back to TASK_RUNNING in |
2989 |
++ * an atomic manner. |
2990 |
++ * |
2991 |
++ * By taking task_rq(p)->lock we serialize against schedule(), if @p->on_rq |
2992 |
++ * then schedule() must still happen and p->state can be changed to |
2993 |
++ * TASK_RUNNING. Otherwise we lost the race, schedule() has happened, and we |
2994 |
++ * need to do a full wakeup with enqueue. |
2995 |
++ * |
2996 |
++ * Returns: %true when the wakeup is done, |
2997 |
++ * %false otherwise. |
2998 |
++ */ |
2999 |
++static int ttwu_runnable(struct task_struct *p, int wake_flags) |
3000 |
++{ |
3001 |
++ struct rq *rq; |
3002 |
++ raw_spinlock_t *lock; |
3003 |
++ int ret = 0; |
3004 |
++ |
3005 |
++ rq = __task_access_lock(p, &lock); |
3006 |
++ if (task_on_rq_queued(p)) { |
3007 |
++ /* check_preempt_curr() may use rq clock */ |
3008 |
++ update_rq_clock(rq); |
3009 |
++ ttwu_do_wakeup(rq, p, wake_flags); |
3010 |
++ ret = 1; |
3011 |
++ } |
3012 |
++ __task_access_unlock(p, lock); |
3013 |
++ |
3014 |
++ return ret; |
3015 |
++} |
3016 |
++ |
3017 |
++#ifdef CONFIG_SMP |
3018 |
++void sched_ttwu_pending(void *arg) |
3019 |
++{ |
3020 |
++ struct llist_node *llist = arg; |
3021 |
++ struct rq *rq = this_rq(); |
3022 |
++ struct task_struct *p, *t; |
3023 |
++ struct rq_flags rf; |
3024 |
++ |
3025 |
++ if (!llist) |
3026 |
++ return; |
3027 |
++ |
3028 |
++ /* |
3029 |
++ * rq::ttwu_pending racy indication of out-standing wakeups. |
3030 |
++ * Races such that false-negatives are possible, since they |
3031 |
++ * are shorter lived that false-positives would be. |
3032 |
++ */ |
3033 |
++ WRITE_ONCE(rq->ttwu_pending, 0); |
3034 |
++ |
3035 |
++ rq_lock_irqsave(rq, &rf); |
3036 |
++ update_rq_clock(rq); |
3037 |
++ |
3038 |
++ llist_for_each_entry_safe(p, t, llist, wake_entry.llist) { |
3039 |
++ if (WARN_ON_ONCE(p->on_cpu)) |
3040 |
++ smp_cond_load_acquire(&p->on_cpu, !VAL); |
3041 |
++ |
3042 |
++ if (WARN_ON_ONCE(task_cpu(p) != cpu_of(rq))) |
3043 |
++ set_task_cpu(p, cpu_of(rq)); |
3044 |
++ |
3045 |
++ ttwu_do_activate(rq, p, p->sched_remote_wakeup ? WF_MIGRATED : 0); |
3046 |
++ } |
3047 |
++ |
3048 |
++ rq_unlock_irqrestore(rq, &rf); |
3049 |
++} |
3050 |
++ |
3051 |
++void send_call_function_single_ipi(int cpu) |
3052 |
++{ |
3053 |
++ struct rq *rq = cpu_rq(cpu); |
3054 |
++ |
3055 |
++ if (!set_nr_if_polling(rq->idle)) |
3056 |
++ arch_send_call_function_single_ipi(cpu); |
3057 |
++ else |
3058 |
++ trace_sched_wake_idle_without_ipi(cpu); |
3059 |
++} |
3060 |
++ |
3061 |
++/* |
3062 |
++ * Queue a task on the target CPUs wake_list and wake the CPU via IPI if |
3063 |
++ * necessary. The wakee CPU on receipt of the IPI will queue the task |
3064 |
++ * via sched_ttwu_wakeup() for activation so the wakee incurs the cost |
3065 |
++ * of the wakeup instead of the waker. |
3066 |
++ */ |
3067 |
++static void __ttwu_queue_wakelist(struct task_struct *p, int cpu, int wake_flags) |
3068 |
++{ |
3069 |
++ struct rq *rq = cpu_rq(cpu); |
3070 |
++ |
3071 |
++ p->sched_remote_wakeup = !!(wake_flags & WF_MIGRATED); |
3072 |
++ |
3073 |
++ WRITE_ONCE(rq->ttwu_pending, 1); |
3074 |
++ __smp_call_single_queue(cpu, &p->wake_entry.llist); |
3075 |
++} |
3076 |
++ |
3077 |
++static inline bool ttwu_queue_cond(int cpu, int wake_flags) |
3078 |
++{ |
3079 |
++ /* |
3080 |
++ * Do not complicate things with the async wake_list while the CPU is |
3081 |
++ * in hotplug state. |
3082 |
++ */ |
3083 |
++ if (!cpu_active(cpu)) |
3084 |
++ return false; |
3085 |
++ |
3086 |
++ /* |
3087 |
++ * If the CPU does not share cache, then queue the task on the |
3088 |
++ * remote rqs wakelist to avoid accessing remote data. |
3089 |
++ */ |
3090 |
++ if (!cpus_share_cache(smp_processor_id(), cpu)) |
3091 |
++ return true; |
3092 |
++ |
3093 |
++ /* |
3094 |
++ * If the task is descheduling and the only running task on the |
3095 |
++ * CPU then use the wakelist to offload the task activation to |
3096 |
++ * the soon-to-be-idle CPU as the current CPU is likely busy. |
3097 |
++ * nr_running is checked to avoid unnecessary task stacking. |
3098 |
++ */ |
3099 |
++ if ((wake_flags & WF_ON_CPU) && cpu_rq(cpu)->nr_running <= 1) |
3100 |
++ return true; |
3101 |
++ |
3102 |
++ return false; |
3103 |
++} |
3104 |
++ |
3105 |
++static bool ttwu_queue_wakelist(struct task_struct *p, int cpu, int wake_flags) |
3106 |
++{ |
3107 |
++ if (__is_defined(ALT_SCHED_TTWU_QUEUE) && ttwu_queue_cond(cpu, wake_flags)) { |
3108 |
++ if (WARN_ON_ONCE(cpu == smp_processor_id())) |
3109 |
++ return false; |
3110 |
++ |
3111 |
++ sched_clock_cpu(cpu); /* Sync clocks across CPUs */ |
3112 |
++ __ttwu_queue_wakelist(p, cpu, wake_flags); |
3113 |
++ return true; |
3114 |
++ } |
3115 |
++ |
3116 |
++ return false; |
3117 |
++} |
3118 |
++ |
3119 |
++void wake_up_if_idle(int cpu) |
3120 |
++{ |
3121 |
++ struct rq *rq = cpu_rq(cpu); |
3122 |
++ unsigned long flags; |
3123 |
++ |
3124 |
++ rcu_read_lock(); |
3125 |
++ |
3126 |
++ if (!is_idle_task(rcu_dereference(rq->curr))) |
3127 |
++ goto out; |
3128 |
++ |
3129 |
++ raw_spin_lock_irqsave(&rq->lock, flags); |
3130 |
++ if (is_idle_task(rq->curr)) |
3131 |
++ resched_curr(rq); |
3132 |
++ /* Else CPU is not idle, do nothing here */ |
3133 |
++ raw_spin_unlock_irqrestore(&rq->lock, flags); |
3134 |
++ |
3135 |
++out: |
3136 |
++ rcu_read_unlock(); |
3137 |
++} |
3138 |
++ |
3139 |
++bool cpus_share_cache(int this_cpu, int that_cpu) |
3140 |
++{ |
3141 |
++ if (this_cpu == that_cpu) |
3142 |
++ return true; |
3143 |
++ |
3144 |
++ return per_cpu(sd_llc_id, this_cpu) == per_cpu(sd_llc_id, that_cpu); |
3145 |
++} |
3146 |
++#else /* !CONFIG_SMP */ |
3147 |
++ |
3148 |
++static inline bool ttwu_queue_wakelist(struct task_struct *p, int cpu, int wake_flags) |
3149 |
++{ |
3150 |
++ return false; |
3151 |
++} |
3152 |
++ |
3153 |
++#endif /* CONFIG_SMP */ |
3154 |
++ |
3155 |
++static inline void ttwu_queue(struct task_struct *p, int cpu, int wake_flags) |
3156 |
++{ |
3157 |
++ struct rq *rq = cpu_rq(cpu); |
3158 |
++ |
3159 |
++ if (ttwu_queue_wakelist(p, cpu, wake_flags)) |
3160 |
++ return; |
3161 |
++ |
3162 |
++ raw_spin_lock(&rq->lock); |
3163 |
++ update_rq_clock(rq); |
3164 |
++ ttwu_do_activate(rq, p, wake_flags); |
3165 |
++ raw_spin_unlock(&rq->lock); |
3166 |
++} |
3167 |
++ |
3168 |
++/* |
3169 |
++ * Invoked from try_to_wake_up() to check whether the task can be woken up. |
3170 |
++ * |
3171 |
++ * The caller holds p::pi_lock if p != current or has preemption |
3172 |
++ * disabled when p == current. |
3173 |
++ * |
3174 |
++ * The rules of PREEMPT_RT saved_state: |
3175 |
++ * |
3176 |
++ * The related locking code always holds p::pi_lock when updating |
3177 |
++ * p::saved_state, which means the code is fully serialized in both cases. |
3178 |
++ * |
3179 |
++ * The lock wait and lock wakeups happen via TASK_RTLOCK_WAIT. No other |
3180 |
++ * bits set. This allows to distinguish all wakeup scenarios. |
3181 |
++ */ |
3182 |
++static __always_inline |
3183 |
++bool ttwu_state_match(struct task_struct *p, unsigned int state, int *success) |
3184 |
++{ |
3185 |
++ if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) { |
3186 |
++ WARN_ON_ONCE((state & TASK_RTLOCK_WAIT) && |
3187 |
++ state != TASK_RTLOCK_WAIT); |
3188 |
++ } |
3189 |
++ |
3190 |
++ if (READ_ONCE(p->__state) & state) { |
3191 |
++ *success = 1; |
3192 |
++ return true; |
3193 |
++ } |
3194 |
++ |
3195 |
++#ifdef CONFIG_PREEMPT_RT |
3196 |
++ /* |
3197 |
++ * Saved state preserves the task state across blocking on |
3198 |
++ * an RT lock. If the state matches, set p::saved_state to |
3199 |
++ * TASK_RUNNING, but do not wake the task because it waits |
3200 |
++ * for a lock wakeup. Also indicate success because from |
3201 |
++ * the regular waker's point of view this has succeeded. |
3202 |
++ * |
3203 |
++ * After acquiring the lock the task will restore p::__state |
3204 |
++ * from p::saved_state which ensures that the regular |
3205 |
++ * wakeup is not lost. The restore will also set |
3206 |
++ * p::saved_state to TASK_RUNNING so any further tests will |
3207 |
++ * not result in false positives vs. @success |
3208 |
++ */ |
3209 |
++ if (p->saved_state & state) { |
3210 |
++ p->saved_state = TASK_RUNNING; |
3211 |
++ *success = 1; |
3212 |
++ } |
3213 |
++#endif |
3214 |
++ return false; |
3215 |
++} |
3216 |
++ |
3217 |
++/* |
3218 |
++ * Notes on Program-Order guarantees on SMP systems. |
3219 |
++ * |
3220 |
++ * MIGRATION |
3221 |
++ * |
3222 |
++ * The basic program-order guarantee on SMP systems is that when a task [t] |
3223 |
++ * migrates, all its activity on its old CPU [c0] happens-before any subsequent |
3224 |
++ * execution on its new CPU [c1]. |
3225 |
++ * |
3226 |
++ * For migration (of runnable tasks) this is provided by the following means: |
3227 |
++ * |
3228 |
++ * A) UNLOCK of the rq(c0)->lock scheduling out task t |
3229 |
++ * B) migration for t is required to synchronize *both* rq(c0)->lock and |
3230 |
++ * rq(c1)->lock (if not at the same time, then in that order). |
3231 |
++ * C) LOCK of the rq(c1)->lock scheduling in task |
3232 |
++ * |
3233 |
++ * Transitivity guarantees that B happens after A and C after B. |
3234 |
++ * Note: we only require RCpc transitivity. |
3235 |
++ * Note: the CPU doing B need not be c0 or c1 |
3236 |
++ * |
3237 |
++ * Example: |
3238 |
++ * |
3239 |
++ * CPU0 CPU1 CPU2 |
3240 |
++ * |
3241 |
++ * LOCK rq(0)->lock |
3242 |
++ * sched-out X |
3243 |
++ * sched-in Y |
3244 |
++ * UNLOCK rq(0)->lock |
3245 |
++ * |
3246 |
++ * LOCK rq(0)->lock // orders against CPU0 |
3247 |
++ * dequeue X |
3248 |
++ * UNLOCK rq(0)->lock |
3249 |
++ * |
3250 |
++ * LOCK rq(1)->lock |
3251 |
++ * enqueue X |
3252 |
++ * UNLOCK rq(1)->lock |
3253 |
++ * |
3254 |
++ * LOCK rq(1)->lock // orders against CPU2 |
3255 |
++ * sched-out Z |
3256 |
++ * sched-in X |
3257 |
++ * UNLOCK rq(1)->lock |
3258 |
++ * |
3259 |
++ * |
3260 |
++ * BLOCKING -- aka. SLEEP + WAKEUP |
3261 |
++ * |
3262 |
++ * For blocking we (obviously) need to provide the same guarantee as for |
3263 |
++ * migration. However the means are completely different as there is no lock |
3264 |
++ * chain to provide order. Instead we do: |
3265 |
++ * |
3266 |
++ * 1) smp_store_release(X->on_cpu, 0) -- finish_task() |
3267 |
++ * 2) smp_cond_load_acquire(!X->on_cpu) -- try_to_wake_up() |
3268 |
++ * |
3269 |
++ * Example: |
3270 |
++ * |
3271 |
++ * CPU0 (schedule) CPU1 (try_to_wake_up) CPU2 (schedule) |
3272 |
++ * |
3273 |
++ * LOCK rq(0)->lock LOCK X->pi_lock |
3274 |
++ * dequeue X |
3275 |
++ * sched-out X |
3276 |
++ * smp_store_release(X->on_cpu, 0); |
3277 |
++ * |
3278 |
++ * smp_cond_load_acquire(&X->on_cpu, !VAL); |
3279 |
++ * X->state = WAKING |
3280 |
++ * set_task_cpu(X,2) |
3281 |
++ * |
3282 |
++ * LOCK rq(2)->lock |
3283 |
++ * enqueue X |
3284 |
++ * X->state = RUNNING |
3285 |
++ * UNLOCK rq(2)->lock |
3286 |
++ * |
3287 |
++ * LOCK rq(2)->lock // orders against CPU1 |
3288 |
++ * sched-out Z |
3289 |
++ * sched-in X |
3290 |
++ * UNLOCK rq(2)->lock |
3291 |
++ * |
3292 |
++ * UNLOCK X->pi_lock |
3293 |
++ * UNLOCK rq(0)->lock |
3294 |
++ * |
3295 |
++ * |
3296 |
++ * However; for wakeups there is a second guarantee we must provide, namely we |
3297 |
++ * must observe the state that lead to our wakeup. That is, not only must our |
3298 |
++ * task observe its own prior state, it must also observe the stores prior to |
3299 |
++ * its wakeup. |
3300 |
++ * |
3301 |
++ * This means that any means of doing remote wakeups must order the CPU doing |
3302 |
++ * the wakeup against the CPU the task is going to end up running on. This, |
3303 |
++ * however, is already required for the regular Program-Order guarantee above, |
3304 |
++ * since the waking CPU is the one issueing the ACQUIRE (smp_cond_load_acquire). |
3305 |
++ * |
3306 |
++ */ |
3307 |
++ |
3308 |
++/** |
3309 |
++ * try_to_wake_up - wake up a thread |
3310 |
++ * @p: the thread to be awakened |
3311 |
++ * @state: the mask of task states that can be woken |
3312 |
++ * @wake_flags: wake modifier flags (WF_*) |
3313 |
++ * |
3314 |
++ * Conceptually does: |
3315 |
++ * |
3316 |
++ * If (@state & @p->state) @p->state = TASK_RUNNING. |
3317 |
++ * |
3318 |
++ * If the task was not queued/runnable, also place it back on a runqueue. |
3319 |
++ * |
3320 |
++ * This function is atomic against schedule() which would dequeue the task. |
3321 |
++ * |
3322 |
++ * It issues a full memory barrier before accessing @p->state, see the comment |
3323 |
++ * with set_current_state(). |
3324 |
++ * |
3325 |
++ * Uses p->pi_lock to serialize against concurrent wake-ups. |
3326 |
++ * |
3327 |
++ * Relies on p->pi_lock stabilizing: |
3328 |
++ * - p->sched_class |
3329 |
++ * - p->cpus_ptr |
3330 |
++ * - p->sched_task_group |
3331 |
++ * in order to do migration, see its use of select_task_rq()/set_task_cpu(). |
3332 |
++ * |
3333 |
++ * Tries really hard to only take one task_rq(p)->lock for performance. |
3334 |
++ * Takes rq->lock in: |
3335 |
++ * - ttwu_runnable() -- old rq, unavoidable, see comment there; |
3336 |
++ * - ttwu_queue() -- new rq, for enqueue of the task; |
3337 |
++ * - psi_ttwu_dequeue() -- much sadness :-( accounting will kill us. |
3338 |
++ * |
3339 |
++ * As a consequence we race really badly with just about everything. See the |
3340 |
++ * many memory barriers and their comments for details. |
3341 |
++ * |
3342 |
++ * Return: %true if @p->state changes (an actual wakeup was done), |
3343 |
++ * %false otherwise. |
3344 |
++ */ |
3345 |
++static int try_to_wake_up(struct task_struct *p, unsigned int state, |
3346 |
++ int wake_flags) |
3347 |
++{ |
3348 |
++ unsigned long flags; |
3349 |
++ int cpu, success = 0; |
3350 |
++ |
3351 |
++ preempt_disable(); |
3352 |
++ if (p == current) { |
3353 |
++ /* |
3354 |
++ * We're waking current, this means 'p->on_rq' and 'task_cpu(p) |
3355 |
++ * == smp_processor_id()'. Together this means we can special |
3356 |
++ * case the whole 'p->on_rq && ttwu_runnable()' case below |
3357 |
++ * without taking any locks. |
3358 |
++ * |
3359 |
++ * In particular: |
3360 |
++ * - we rely on Program-Order guarantees for all the ordering, |
3361 |
++ * - we're serialized against set_special_state() by virtue of |
3362 |
++ * it disabling IRQs (this allows not taking ->pi_lock). |
3363 |
++ */ |
3364 |
++ if (!ttwu_state_match(p, state, &success)) |
3365 |
++ goto out; |
3366 |
++ |
3367 |
++ trace_sched_waking(p); |
3368 |
++ WRITE_ONCE(p->__state, TASK_RUNNING); |
3369 |
++ trace_sched_wakeup(p); |
3370 |
++ goto out; |
3371 |
++ } |
3372 |
++ |
3373 |
++ /* |
3374 |
++ * If we are going to wake up a thread waiting for CONDITION we |
3375 |
++ * need to ensure that CONDITION=1 done by the caller can not be |
3376 |
++ * reordered with p->state check below. This pairs with smp_store_mb() |
3377 |
++ * in set_current_state() that the waiting thread does. |
3378 |
++ */ |
3379 |
++ raw_spin_lock_irqsave(&p->pi_lock, flags); |
3380 |
++ smp_mb__after_spinlock(); |
3381 |
++ if (!ttwu_state_match(p, state, &success)) |
3382 |
++ goto unlock; |
3383 |
++ |
3384 |
++ trace_sched_waking(p); |
3385 |
++ |
3386 |
++ /* |
3387 |
++ * Ensure we load p->on_rq _after_ p->state, otherwise it would |
3388 |
++ * be possible to, falsely, observe p->on_rq == 0 and get stuck |
3389 |
++ * in smp_cond_load_acquire() below. |
3390 |
++ * |
3391 |
++ * sched_ttwu_pending() try_to_wake_up() |
3392 |
++ * STORE p->on_rq = 1 LOAD p->state |
3393 |
++ * UNLOCK rq->lock |
3394 |
++ * |
3395 |
++ * __schedule() (switch to task 'p') |
3396 |
++ * LOCK rq->lock smp_rmb(); |
3397 |
++ * smp_mb__after_spinlock(); |
3398 |
++ * UNLOCK rq->lock |
3399 |
++ * |
3400 |
++ * [task p] |
3401 |
++ * STORE p->state = UNINTERRUPTIBLE LOAD p->on_rq |
3402 |
++ * |
3403 |
++ * Pairs with the LOCK+smp_mb__after_spinlock() on rq->lock in |
3404 |
++ * __schedule(). See the comment for smp_mb__after_spinlock(). |
3405 |
++ * |
3406 |
++ * A similar smb_rmb() lives in try_invoke_on_locked_down_task(). |
3407 |
++ */ |
3408 |
++ smp_rmb(); |
3409 |
++ if (READ_ONCE(p->on_rq) && ttwu_runnable(p, wake_flags)) |
3410 |
++ goto unlock; |
3411 |
++ |
3412 |
++#ifdef CONFIG_SMP |
3413 |
++ /* |
3414 |
++ * Ensure we load p->on_cpu _after_ p->on_rq, otherwise it would be |
3415 |
++ * possible to, falsely, observe p->on_cpu == 0. |
3416 |
++ * |
3417 |
++ * One must be running (->on_cpu == 1) in order to remove oneself |
3418 |
++ * from the runqueue. |
3419 |
++ * |
3420 |
++ * __schedule() (switch to task 'p') try_to_wake_up() |
3421 |
++ * STORE p->on_cpu = 1 LOAD p->on_rq |
3422 |
++ * UNLOCK rq->lock |
3423 |
++ * |
3424 |
++ * __schedule() (put 'p' to sleep) |
3425 |
++ * LOCK rq->lock smp_rmb(); |
3426 |
++ * smp_mb__after_spinlock(); |
3427 |
++ * STORE p->on_rq = 0 LOAD p->on_cpu |
3428 |
++ * |
3429 |
++ * Pairs with the LOCK+smp_mb__after_spinlock() on rq->lock in |
3430 |
++ * __schedule(). See the comment for smp_mb__after_spinlock(). |
3431 |
++ * |
3432 |
++ * Form a control-dep-acquire with p->on_rq == 0 above, to ensure |
3433 |
++ * schedule()'s deactivate_task() has 'happened' and p will no longer |
3434 |
++ * care about it's own p->state. See the comment in __schedule(). |
3435 |
++ */ |
3436 |
++ smp_acquire__after_ctrl_dep(); |
3437 |
++ |
3438 |
++ /* |
3439 |
++ * We're doing the wakeup (@success == 1), they did a dequeue (p->on_rq |
3440 |
++ * == 0), which means we need to do an enqueue, change p->state to |
3441 |
++ * TASK_WAKING such that we can unlock p->pi_lock before doing the |
3442 |
++ * enqueue, such as ttwu_queue_wakelist(). |
3443 |
++ */ |
3444 |
++ WRITE_ONCE(p->__state, TASK_WAKING); |
3445 |
++ |
3446 |
++ /* |
3447 |
++ * If the owning (remote) CPU is still in the middle of schedule() with |
3448 |
++ * this task as prev, considering queueing p on the remote CPUs wake_list |
3449 |
++ * which potentially sends an IPI instead of spinning on p->on_cpu to |
3450 |
++ * let the waker make forward progress. This is safe because IRQs are |
3451 |
++ * disabled and the IPI will deliver after on_cpu is cleared. |
3452 |
++ * |
3453 |
++ * Ensure we load task_cpu(p) after p->on_cpu: |
3454 |
++ * |
3455 |
++ * set_task_cpu(p, cpu); |
3456 |
++ * STORE p->cpu = @cpu |
3457 |
++ * __schedule() (switch to task 'p') |
3458 |
++ * LOCK rq->lock |
3459 |
++ * smp_mb__after_spin_lock() smp_cond_load_acquire(&p->on_cpu) |
3460 |
++ * STORE p->on_cpu = 1 LOAD p->cpu |
3461 |
++ * |
3462 |
++ * to ensure we observe the correct CPU on which the task is currently |
3463 |
++ * scheduling. |
3464 |
++ */ |
3465 |
++ if (smp_load_acquire(&p->on_cpu) && |
3466 |
++ ttwu_queue_wakelist(p, task_cpu(p), wake_flags | WF_ON_CPU)) |
3467 |
++ goto unlock; |
3468 |
++ |
3469 |
++ /* |
3470 |
++ * If the owning (remote) CPU is still in the middle of schedule() with |
3471 |
++ * this task as prev, wait until it's done referencing the task. |
3472 |
++ * |
3473 |
++ * Pairs with the smp_store_release() in finish_task(). |
3474 |
++ * |
3475 |
++ * This ensures that tasks getting woken will be fully ordered against |
3476 |
++ * their previous state and preserve Program Order. |
3477 |
++ */ |
3478 |
++ smp_cond_load_acquire(&p->on_cpu, !VAL); |
3479 |
++ |
3480 |
++ sched_task_ttwu(p); |
3481 |
++ |
3482 |
++ cpu = select_task_rq(p); |
3483 |
++ |
3484 |
++ if (cpu != task_cpu(p)) { |
3485 |
++ if (p->in_iowait) { |
3486 |
++ delayacct_blkio_end(p); |
3487 |
++ atomic_dec(&task_rq(p)->nr_iowait); |
3488 |
++ } |
3489 |
++ |
3490 |
++ wake_flags |= WF_MIGRATED; |
3491 |
++ psi_ttwu_dequeue(p); |
3492 |
++ set_task_cpu(p, cpu); |
3493 |
++ } |
3494 |
++#else |
3495 |
++ cpu = task_cpu(p); |
3496 |
++#endif /* CONFIG_SMP */ |
3497 |
++ |
3498 |
++ ttwu_queue(p, cpu, wake_flags); |
3499 |
++unlock: |
3500 |
++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
3501 |
++out: |
3502 |
++ if (success) |
3503 |
++ ttwu_stat(p, task_cpu(p), wake_flags); |
3504 |
++ preempt_enable(); |
3505 |
++ |
3506 |
++ return success; |
3507 |
++} |
3508 |
++ |
3509 |
++/** |
3510 |
++ * task_call_func - Invoke a function on task in fixed state |
3511 |
++ * @p: Process for which the function is to be invoked, can be @current. |
3512 |
++ * @func: Function to invoke. |
3513 |
++ * @arg: Argument to function. |
3514 |
++ * |
3515 |
++ * Fix the task in it's current state by avoiding wakeups and or rq operations |
3516 |
++ * and call @func(@arg) on it. This function can use ->on_rq and task_curr() |
3517 |
++ * to work out what the state is, if required. Given that @func can be invoked |
3518 |
++ * with a runqueue lock held, it had better be quite lightweight. |
3519 |
++ * |
3520 |
++ * Returns: |
3521 |
++ * Whatever @func returns |
3522 |
++ */ |
3523 |
++int task_call_func(struct task_struct *p, task_call_f func, void *arg) |
3524 |
++{ |
3525 |
++ struct rq *rq = NULL; |
3526 |
++ unsigned int state; |
3527 |
++ struct rq_flags rf; |
3528 |
++ int ret; |
3529 |
++ |
3530 |
++ raw_spin_lock_irqsave(&p->pi_lock, rf.flags); |
3531 |
++ |
3532 |
++ state = READ_ONCE(p->__state); |
3533 |
++ |
3534 |
++ /* |
3535 |
++ * Ensure we load p->on_rq after p->__state, otherwise it would be |
3536 |
++ * possible to, falsely, observe p->on_rq == 0. |
3537 |
++ * |
3538 |
++ * See try_to_wake_up() for a longer comment. |
3539 |
++ */ |
3540 |
++ smp_rmb(); |
3541 |
++ |
3542 |
++ /* |
3543 |
++ * Since pi->lock blocks try_to_wake_up(), we don't need rq->lock when |
3544 |
++ * the task is blocked. Make sure to check @state since ttwu() can drop |
3545 |
++ * locks at the end, see ttwu_queue_wakelist(). |
3546 |
++ */ |
3547 |
++ if (state == TASK_RUNNING || state == TASK_WAKING || p->on_rq) |
3548 |
++ rq = __task_rq_lock(p, &rf); |
3549 |
++ |
3550 |
++ /* |
3551 |
++ * At this point the task is pinned; either: |
3552 |
++ * - blocked and we're holding off wakeups (pi->lock) |
3553 |
++ * - woken, and we're holding off enqueue (rq->lock) |
3554 |
++ * - queued, and we're holding off schedule (rq->lock) |
3555 |
++ * - running, and we're holding off de-schedule (rq->lock) |
3556 |
++ * |
3557 |
++ * The called function (@func) can use: task_curr(), p->on_rq and |
3558 |
++ * p->__state to differentiate between these states. |
3559 |
++ */ |
3560 |
++ ret = func(p, arg); |
3561 |
++ |
3562 |
++ if (rq) |
3563 |
++ __task_rq_unlock(rq, &rf); |
3564 |
++ |
3565 |
++ raw_spin_unlock_irqrestore(&p->pi_lock, rf.flags); |
3566 |
++ return ret; |
3567 |
++} |
3568 |
++ |
3569 |
++/** |
3570 |
++ * wake_up_process - Wake up a specific process |
3571 |
++ * @p: The process to be woken up. |
3572 |
++ * |
3573 |
++ * Attempt to wake up the nominated process and move it to the set of runnable |
3574 |
++ * processes. |
3575 |
++ * |
3576 |
++ * Return: 1 if the process was woken up, 0 if it was already running. |
3577 |
++ * |
3578 |
++ * This function executes a full memory barrier before accessing the task state. |
3579 |
++ */ |
3580 |
++int wake_up_process(struct task_struct *p) |
3581 |
++{ |
3582 |
++ return try_to_wake_up(p, TASK_NORMAL, 0); |
3583 |
++} |
3584 |
++EXPORT_SYMBOL(wake_up_process); |
3585 |
++ |
3586 |
++int wake_up_state(struct task_struct *p, unsigned int state) |
3587 |
++{ |
3588 |
++ return try_to_wake_up(p, state, 0); |
3589 |
++} |
3590 |
++ |
3591 |
++/* |
3592 |
++ * Perform scheduler related setup for a newly forked process p. |
3593 |
++ * p is forked by current. |
3594 |
++ * |
3595 |
++ * __sched_fork() is basic setup used by init_idle() too: |
3596 |
++ */ |
3597 |
++static inline void __sched_fork(unsigned long clone_flags, struct task_struct *p) |
3598 |
++{ |
3599 |
++ p->on_rq = 0; |
3600 |
++ p->on_cpu = 0; |
3601 |
++ p->utime = 0; |
3602 |
++ p->stime = 0; |
3603 |
++ p->sched_time = 0; |
3604 |
++ |
3605 |
++#ifdef CONFIG_SCHEDSTATS |
3606 |
++ /* Even if schedstat is disabled, there should not be garbage */ |
3607 |
++ memset(&p->stats, 0, sizeof(p->stats)); |
3608 |
++#endif |
3609 |
++ |
3610 |
++#ifdef CONFIG_PREEMPT_NOTIFIERS |
3611 |
++ INIT_HLIST_HEAD(&p->preempt_notifiers); |
3612 |
++#endif |
3613 |
++ |
3614 |
++#ifdef CONFIG_COMPACTION |
3615 |
++ p->capture_control = NULL; |
3616 |
++#endif |
3617 |
++#ifdef CONFIG_SMP |
3618 |
++ p->wake_entry.u_flags = CSD_TYPE_TTWU; |
3619 |
++#endif |
3620 |
++} |
3621 |
++ |
3622 |
++/* |
3623 |
++ * fork()/clone()-time setup: |
3624 |
++ */ |
3625 |
++int sched_fork(unsigned long clone_flags, struct task_struct *p) |
3626 |
++{ |
3627 |
++ __sched_fork(clone_flags, p); |
3628 |
++ /* |
3629 |
++ * We mark the process as NEW here. This guarantees that |
3630 |
++ * nobody will actually run it, and a signal or other external |
3631 |
++ * event cannot wake it up and insert it on the runqueue either. |
3632 |
++ */ |
3633 |
++ p->__state = TASK_NEW; |
3634 |
++ |
3635 |
++ /* |
3636 |
++ * Make sure we do not leak PI boosting priority to the child. |
3637 |
++ */ |
3638 |
++ p->prio = current->normal_prio; |
3639 |
++ |
3640 |
++ /* |
3641 |
++ * Revert to default priority/policy on fork if requested. |
3642 |
++ */ |
3643 |
++ if (unlikely(p->sched_reset_on_fork)) { |
3644 |
++ if (task_has_rt_policy(p)) { |
3645 |
++ p->policy = SCHED_NORMAL; |
3646 |
++ p->static_prio = NICE_TO_PRIO(0); |
3647 |
++ p->rt_priority = 0; |
3648 |
++ } else if (PRIO_TO_NICE(p->static_prio) < 0) |
3649 |
++ p->static_prio = NICE_TO_PRIO(0); |
3650 |
++ |
3651 |
++ p->prio = p->normal_prio = p->static_prio; |
3652 |
++ |
3653 |
++ /* |
3654 |
++ * We don't need the reset flag anymore after the fork. It has |
3655 |
++ * fulfilled its duty: |
3656 |
++ */ |
3657 |
++ p->sched_reset_on_fork = 0; |
3658 |
++ } |
3659 |
++ |
3660 |
++#ifdef CONFIG_SCHED_INFO |
3661 |
++ if (unlikely(sched_info_on())) |
3662 |
++ memset(&p->sched_info, 0, sizeof(p->sched_info)); |
3663 |
++#endif |
3664 |
++ init_task_preempt_count(p); |
3665 |
++ |
3666 |
++ return 0; |
3667 |
++} |
3668 |
++ |
3669 |
++void sched_cgroup_fork(struct task_struct *p, struct kernel_clone_args *kargs) |
3670 |
++{ |
3671 |
++ unsigned long flags; |
3672 |
++ struct rq *rq; |
3673 |
++ |
3674 |
++ /* |
3675 |
++ * Because we're not yet on the pid-hash, p->pi_lock isn't strictly |
3676 |
++ * required yet, but lockdep gets upset if rules are violated. |
3677 |
++ */ |
3678 |
++ raw_spin_lock_irqsave(&p->pi_lock, flags); |
3679 |
++ /* |
3680 |
++ * Share the timeslice between parent and child, thus the |
3681 |
++ * total amount of pending timeslices in the system doesn't change, |
3682 |
++ * resulting in more scheduling fairness. |
3683 |
++ */ |
3684 |
++ rq = this_rq(); |
3685 |
++ raw_spin_lock(&rq->lock); |
3686 |
++ |
3687 |
++ rq->curr->time_slice /= 2; |
3688 |
++ p->time_slice = rq->curr->time_slice; |
3689 |
++#ifdef CONFIG_SCHED_HRTICK |
3690 |
++ hrtick_start(rq, rq->curr->time_slice); |
3691 |
++#endif |
3692 |
++ |
3693 |
++ if (p->time_slice < RESCHED_NS) { |
3694 |
++ p->time_slice = sched_timeslice_ns; |
3695 |
++ resched_curr(rq); |
3696 |
++ } |
3697 |
++ sched_task_fork(p, rq); |
3698 |
++ raw_spin_unlock(&rq->lock); |
3699 |
++ |
3700 |
++ rseq_migrate(p); |
3701 |
++ /* |
3702 |
++ * We're setting the CPU for the first time, we don't migrate, |
3703 |
++ * so use __set_task_cpu(). |
3704 |
++ */ |
3705 |
++ __set_task_cpu(p, smp_processor_id()); |
3706 |
++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
3707 |
++} |
3708 |
++ |
3709 |
++void sched_post_fork(struct task_struct *p) |
3710 |
++{ |
3711 |
++} |
3712 |
++ |
3713 |
++#ifdef CONFIG_SCHEDSTATS |
3714 |
++ |
3715 |
++DEFINE_STATIC_KEY_FALSE(sched_schedstats); |
3716 |
++ |
3717 |
++static void set_schedstats(bool enabled) |
3718 |
++{ |
3719 |
++ if (enabled) |
3720 |
++ static_branch_enable(&sched_schedstats); |
3721 |
++ else |
3722 |
++ static_branch_disable(&sched_schedstats); |
3723 |
++} |
3724 |
++ |
3725 |
++void force_schedstat_enabled(void) |
3726 |
++{ |
3727 |
++ if (!schedstat_enabled()) { |
3728 |
++ pr_info("kernel profiling enabled schedstats, disable via kernel.sched_schedstats.\n"); |
3729 |
++ static_branch_enable(&sched_schedstats); |
3730 |
++ } |
3731 |
++} |
3732 |
++ |
3733 |
++static int __init setup_schedstats(char *str) |
3734 |
++{ |
3735 |
++ int ret = 0; |
3736 |
++ if (!str) |
3737 |
++ goto out; |
3738 |
++ |
3739 |
++ if (!strcmp(str, "enable")) { |
3740 |
++ set_schedstats(true); |
3741 |
++ ret = 1; |
3742 |
++ } else if (!strcmp(str, "disable")) { |
3743 |
++ set_schedstats(false); |
3744 |
++ ret = 1; |
3745 |
++ } |
3746 |
++out: |
3747 |
++ if (!ret) |
3748 |
++ pr_warn("Unable to parse schedstats=\n"); |
3749 |
++ |
3750 |
++ return ret; |
3751 |
++} |
3752 |
++__setup("schedstats=", setup_schedstats); |
3753 |
++ |
3754 |
++#ifdef CONFIG_PROC_SYSCTL |
3755 |
++static int sysctl_schedstats(struct ctl_table *table, int write, void *buffer, |
3756 |
++ size_t *lenp, loff_t *ppos) |
3757 |
++{ |
3758 |
++ struct ctl_table t; |
3759 |
++ int err; |
3760 |
++ int state = static_branch_likely(&sched_schedstats); |
3761 |
++ |
3762 |
++ if (write && !capable(CAP_SYS_ADMIN)) |
3763 |
++ return -EPERM; |
3764 |
++ |
3765 |
++ t = *table; |
3766 |
++ t.data = &state; |
3767 |
++ err = proc_dointvec_minmax(&t, write, buffer, lenp, ppos); |
3768 |
++ if (err < 0) |
3769 |
++ return err; |
3770 |
++ if (write) |
3771 |
++ set_schedstats(state); |
3772 |
++ return err; |
3773 |
++} |
3774 |
++ |
3775 |
++static struct ctl_table sched_core_sysctls[] = { |
3776 |
++ { |
3777 |
++ .procname = "sched_schedstats", |
3778 |
++ .data = NULL, |
3779 |
++ .maxlen = sizeof(unsigned int), |
3780 |
++ .mode = 0644, |
3781 |
++ .proc_handler = sysctl_schedstats, |
3782 |
++ .extra1 = SYSCTL_ZERO, |
3783 |
++ .extra2 = SYSCTL_ONE, |
3784 |
++ }, |
3785 |
++ {} |
3786 |
++}; |
3787 |
++static int __init sched_core_sysctl_init(void) |
3788 |
++{ |
3789 |
++ register_sysctl_init("kernel", sched_core_sysctls); |
3790 |
++ return 0; |
3791 |
++} |
3792 |
++late_initcall(sched_core_sysctl_init); |
3793 |
++#endif /* CONFIG_PROC_SYSCTL */ |
3794 |
++#endif /* CONFIG_SCHEDSTATS */ |
3795 |
++ |
3796 |
++/* |
3797 |
++ * wake_up_new_task - wake up a newly created task for the first time. |
3798 |
++ * |
3799 |
++ * This function will do some initial scheduler statistics housekeeping |
3800 |
++ * that must be done for every newly created context, then puts the task |
3801 |
++ * on the runqueue and wakes it. |
3802 |
++ */ |
3803 |
++void wake_up_new_task(struct task_struct *p) |
3804 |
++{ |
3805 |
++ unsigned long flags; |
3806 |
++ struct rq *rq; |
3807 |
++ |
3808 |
++ raw_spin_lock_irqsave(&p->pi_lock, flags); |
3809 |
++ WRITE_ONCE(p->__state, TASK_RUNNING); |
3810 |
++ rq = cpu_rq(select_task_rq(p)); |
3811 |
++#ifdef CONFIG_SMP |
3812 |
++ rseq_migrate(p); |
3813 |
++ /* |
3814 |
++ * Fork balancing, do it here and not earlier because: |
3815 |
++ * - cpus_ptr can change in the fork path |
3816 |
++ * - any previously selected CPU might disappear through hotplug |
3817 |
++ * |
3818 |
++ * Use __set_task_cpu() to avoid calling sched_class::migrate_task_rq, |
3819 |
++ * as we're not fully set-up yet. |
3820 |
++ */ |
3821 |
++ __set_task_cpu(p, cpu_of(rq)); |
3822 |
++#endif |
3823 |
++ |
3824 |
++ raw_spin_lock(&rq->lock); |
3825 |
++ update_rq_clock(rq); |
3826 |
++ |
3827 |
++ activate_task(p, rq); |
3828 |
++ trace_sched_wakeup_new(p); |
3829 |
++ check_preempt_curr(rq); |
3830 |
++ |
3831 |
++ raw_spin_unlock(&rq->lock); |
3832 |
++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
3833 |
++} |
3834 |
++ |
3835 |
++#ifdef CONFIG_PREEMPT_NOTIFIERS |
3836 |
++ |
3837 |
++static DEFINE_STATIC_KEY_FALSE(preempt_notifier_key); |
3838 |
++ |
3839 |
++void preempt_notifier_inc(void) |
3840 |
++{ |
3841 |
++ static_branch_inc(&preempt_notifier_key); |
3842 |
++} |
3843 |
++EXPORT_SYMBOL_GPL(preempt_notifier_inc); |
3844 |
++ |
3845 |
++void preempt_notifier_dec(void) |
3846 |
++{ |
3847 |
++ static_branch_dec(&preempt_notifier_key); |
3848 |
++} |
3849 |
++EXPORT_SYMBOL_GPL(preempt_notifier_dec); |
3850 |
++ |
3851 |
++/** |
3852 |
++ * preempt_notifier_register - tell me when current is being preempted & rescheduled |
3853 |
++ * @notifier: notifier struct to register |
3854 |
++ */ |
3855 |
++void preempt_notifier_register(struct preempt_notifier *notifier) |
3856 |
++{ |
3857 |
++ if (!static_branch_unlikely(&preempt_notifier_key)) |
3858 |
++ WARN(1, "registering preempt_notifier while notifiers disabled\n"); |
3859 |
++ |
3860 |
++ hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); |
3861 |
++} |
3862 |
++EXPORT_SYMBOL_GPL(preempt_notifier_register); |
3863 |
++ |
3864 |
++/** |
3865 |
++ * preempt_notifier_unregister - no longer interested in preemption notifications |
3866 |
++ * @notifier: notifier struct to unregister |
3867 |
++ * |
3868 |
++ * This is *not* safe to call from within a preemption notifier. |
3869 |
++ */ |
3870 |
++void preempt_notifier_unregister(struct preempt_notifier *notifier) |
3871 |
++{ |
3872 |
++ hlist_del(¬ifier->link); |
3873 |
++} |
3874 |
++EXPORT_SYMBOL_GPL(preempt_notifier_unregister); |
3875 |
++ |
3876 |
++static void __fire_sched_in_preempt_notifiers(struct task_struct *curr) |
3877 |
++{ |
3878 |
++ struct preempt_notifier *notifier; |
3879 |
++ |
3880 |
++ hlist_for_each_entry(notifier, &curr->preempt_notifiers, link) |
3881 |
++ notifier->ops->sched_in(notifier, raw_smp_processor_id()); |
3882 |
++} |
3883 |
++ |
3884 |
++static __always_inline void fire_sched_in_preempt_notifiers(struct task_struct *curr) |
3885 |
++{ |
3886 |
++ if (static_branch_unlikely(&preempt_notifier_key)) |
3887 |
++ __fire_sched_in_preempt_notifiers(curr); |
3888 |
++} |
3889 |
++ |
3890 |
++static void |
3891 |
++__fire_sched_out_preempt_notifiers(struct task_struct *curr, |
3892 |
++ struct task_struct *next) |
3893 |
++{ |
3894 |
++ struct preempt_notifier *notifier; |
3895 |
++ |
3896 |
++ hlist_for_each_entry(notifier, &curr->preempt_notifiers, link) |
3897 |
++ notifier->ops->sched_out(notifier, next); |
3898 |
++} |
3899 |
++ |
3900 |
++static __always_inline void |
3901 |
++fire_sched_out_preempt_notifiers(struct task_struct *curr, |
3902 |
++ struct task_struct *next) |
3903 |
++{ |
3904 |
++ if (static_branch_unlikely(&preempt_notifier_key)) |
3905 |
++ __fire_sched_out_preempt_notifiers(curr, next); |
3906 |
++} |
3907 |
++ |
3908 |
++#else /* !CONFIG_PREEMPT_NOTIFIERS */ |
3909 |
++ |
3910 |
++static inline void fire_sched_in_preempt_notifiers(struct task_struct *curr) |
3911 |
++{ |
3912 |
++} |
3913 |
++ |
3914 |
++static inline void |
3915 |
++fire_sched_out_preempt_notifiers(struct task_struct *curr, |
3916 |
++ struct task_struct *next) |
3917 |
++{ |
3918 |
++} |
3919 |
++ |
3920 |
++#endif /* CONFIG_PREEMPT_NOTIFIERS */ |
3921 |
++ |
3922 |
++static inline void prepare_task(struct task_struct *next) |
3923 |
++{ |
3924 |
++ /* |
3925 |
++ * Claim the task as running, we do this before switching to it |
3926 |
++ * such that any running task will have this set. |
3927 |
++ * |
3928 |
++ * See the ttwu() WF_ON_CPU case and its ordering comment. |
3929 |
++ */ |
3930 |
++ WRITE_ONCE(next->on_cpu, 1); |
3931 |
++} |
3932 |
++ |
3933 |
++static inline void finish_task(struct task_struct *prev) |
3934 |
++{ |
3935 |
++#ifdef CONFIG_SMP |
3936 |
++ /* |
3937 |
++ * This must be the very last reference to @prev from this CPU. After |
3938 |
++ * p->on_cpu is cleared, the task can be moved to a different CPU. We |
3939 |
++ * must ensure this doesn't happen until the switch is completely |
3940 |
++ * finished. |
3941 |
++ * |
3942 |
++ * In particular, the load of prev->state in finish_task_switch() must |
3943 |
++ * happen before this. |
3944 |
++ * |
3945 |
++ * Pairs with the smp_cond_load_acquire() in try_to_wake_up(). |
3946 |
++ */ |
3947 |
++ smp_store_release(&prev->on_cpu, 0); |
3948 |
++#else |
3949 |
++ prev->on_cpu = 0; |
3950 |
++#endif |
3951 |
++} |
3952 |
++ |
3953 |
++#ifdef CONFIG_SMP |
3954 |
++ |
3955 |
++static void do_balance_callbacks(struct rq *rq, struct callback_head *head) |
3956 |
++{ |
3957 |
++ void (*func)(struct rq *rq); |
3958 |
++ struct callback_head *next; |
3959 |
++ |
3960 |
++ lockdep_assert_held(&rq->lock); |
3961 |
++ |
3962 |
++ while (head) { |
3963 |
++ func = (void (*)(struct rq *))head->func; |
3964 |
++ next = head->next; |
3965 |
++ head->next = NULL; |
3966 |
++ head = next; |
3967 |
++ |
3968 |
++ func(rq); |
3969 |
++ } |
3970 |
++} |
3971 |
++ |
3972 |
++static void balance_push(struct rq *rq); |
3973 |
++ |
3974 |
++/* |
3975 |
++ * balance_push_callback is a right abuse of the callback interface and plays |
3976 |
++ * by significantly different rules. |
3977 |
++ * |
3978 |
++ * Where the normal balance_callback's purpose is to be ran in the same context |
3979 |
++ * that queued it (only later, when it's safe to drop rq->lock again), |
3980 |
++ * balance_push_callback is specifically targeted at __schedule(). |
3981 |
++ * |
3982 |
++ * This abuse is tolerated because it places all the unlikely/odd cases behind |
3983 |
++ * a single test, namely: rq->balance_callback == NULL. |
3984 |
++ */ |
3985 |
++struct callback_head balance_push_callback = { |
3986 |
++ .next = NULL, |
3987 |
++ .func = (void (*)(struct callback_head *))balance_push, |
3988 |
++}; |
3989 |
++ |
3990 |
++static inline struct callback_head * |
3991 |
++__splice_balance_callbacks(struct rq *rq, bool split) |
3992 |
++{ |
3993 |
++ struct callback_head *head = rq->balance_callback; |
3994 |
++ |
3995 |
++ if (likely(!head)) |
3996 |
++ return NULL; |
3997 |
++ |
3998 |
++ lockdep_assert_rq_held(rq); |
3999 |
++ /* |
4000 |
++ * Must not take balance_push_callback off the list when |
4001 |
++ * splice_balance_callbacks() and balance_callbacks() are not |
4002 |
++ * in the same rq->lock section. |
4003 |
++ * |
4004 |
++ * In that case it would be possible for __schedule() to interleave |
4005 |
++ * and observe the list empty. |
4006 |
++ */ |
4007 |
++ if (split && head == &balance_push_callback) |
4008 |
++ head = NULL; |
4009 |
++ else |
4010 |
++ rq->balance_callback = NULL; |
4011 |
++ |
4012 |
++ return head; |
4013 |
++} |
4014 |
++ |
4015 |
++static inline struct callback_head *splice_balance_callbacks(struct rq *rq) |
4016 |
++{ |
4017 |
++ return __splice_balance_callbacks(rq, true); |
4018 |
++} |
4019 |
++ |
4020 |
++static void __balance_callbacks(struct rq *rq) |
4021 |
++{ |
4022 |
++ do_balance_callbacks(rq, __splice_balance_callbacks(rq, false)); |
4023 |
++} |
4024 |
++ |
4025 |
++static inline void balance_callbacks(struct rq *rq, struct callback_head *head) |
4026 |
++{ |
4027 |
++ unsigned long flags; |
4028 |
++ |
4029 |
++ if (unlikely(head)) { |
4030 |
++ raw_spin_lock_irqsave(&rq->lock, flags); |
4031 |
++ do_balance_callbacks(rq, head); |
4032 |
++ raw_spin_unlock_irqrestore(&rq->lock, flags); |
4033 |
++ } |
4034 |
++} |
4035 |
++ |
4036 |
++#else |
4037 |
++ |
4038 |
++static inline void __balance_callbacks(struct rq *rq) |
4039 |
++{ |
4040 |
++} |
4041 |
++ |
4042 |
++static inline struct callback_head *splice_balance_callbacks(struct rq *rq) |
4043 |
++{ |
4044 |
++ return NULL; |
4045 |
++} |
4046 |
++ |
4047 |
++static inline void balance_callbacks(struct rq *rq, struct callback_head *head) |
4048 |
++{ |
4049 |
++} |
4050 |
++ |
4051 |
++#endif |
4052 |
++ |
4053 |
++static inline void |
4054 |
++prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4055 |
++{ |
4056 |
++ /* |
4057 |
++ * Since the runqueue lock will be released by the next |
4058 |
++ * task (which is an invalid locking op but in the case |
4059 |
++ * of the scheduler it's an obvious special-case), so we |
4060 |
++ * do an early lockdep release here: |
4061 |
++ */ |
4062 |
++ spin_release(&rq->lock.dep_map, _THIS_IP_); |
4063 |
++#ifdef CONFIG_DEBUG_SPINLOCK |
4064 |
++ /* this is a valid case when another task releases the spinlock */ |
4065 |
++ rq->lock.owner = next; |
4066 |
++#endif |
4067 |
++} |
4068 |
++ |
4069 |
++static inline void finish_lock_switch(struct rq *rq) |
4070 |
++{ |
4071 |
++ /* |
4072 |
++ * If we are tracking spinlock dependencies then we have to |
4073 |
++ * fix up the runqueue lock - which gets 'carried over' from |
4074 |
++ * prev into current: |
4075 |
++ */ |
4076 |
++ spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); |
4077 |
++ __balance_callbacks(rq); |
4078 |
++ raw_spin_unlock_irq(&rq->lock); |
4079 |
++} |
4080 |
++ |
4081 |
++/* |
4082 |
++ * NOP if the arch has not defined these: |
4083 |
++ */ |
4084 |
++ |
4085 |
++#ifndef prepare_arch_switch |
4086 |
++# define prepare_arch_switch(next) do { } while (0) |
4087 |
++#endif |
4088 |
++ |
4089 |
++#ifndef finish_arch_post_lock_switch |
4090 |
++# define finish_arch_post_lock_switch() do { } while (0) |
4091 |
++#endif |
4092 |
++ |
4093 |
++static inline void kmap_local_sched_out(void) |
4094 |
++{ |
4095 |
++#ifdef CONFIG_KMAP_LOCAL |
4096 |
++ if (unlikely(current->kmap_ctrl.idx)) |
4097 |
++ __kmap_local_sched_out(); |
4098 |
++#endif |
4099 |
++} |
4100 |
++ |
4101 |
++static inline void kmap_local_sched_in(void) |
4102 |
++{ |
4103 |
++#ifdef CONFIG_KMAP_LOCAL |
4104 |
++ if (unlikely(current->kmap_ctrl.idx)) |
4105 |
++ __kmap_local_sched_in(); |
4106 |
++#endif |
4107 |
++} |
4108 |
++ |
4109 |
++/** |
4110 |
++ * prepare_task_switch - prepare to switch tasks |
4111 |
++ * @rq: the runqueue preparing to switch |
4112 |
++ * @next: the task we are going to switch to. |
4113 |
++ * |
4114 |
++ * This is called with the rq lock held and interrupts off. It must |
4115 |
++ * be paired with a subsequent finish_task_switch after the context |
4116 |
++ * switch. |
4117 |
++ * |
4118 |
++ * prepare_task_switch sets up locking and calls architecture specific |
4119 |
++ * hooks. |
4120 |
++ */ |
4121 |
++static inline void |
4122 |
++prepare_task_switch(struct rq *rq, struct task_struct *prev, |
4123 |
++ struct task_struct *next) |
4124 |
++{ |
4125 |
++ kcov_prepare_switch(prev); |
4126 |
++ sched_info_switch(rq, prev, next); |
4127 |
++ perf_event_task_sched_out(prev, next); |
4128 |
++ rseq_preempt(prev); |
4129 |
++ fire_sched_out_preempt_notifiers(prev, next); |
4130 |
++ kmap_local_sched_out(); |
4131 |
++ prepare_task(next); |
4132 |
++ prepare_arch_switch(next); |
4133 |
++} |
4134 |
++ |
4135 |
++/** |
4136 |
++ * finish_task_switch - clean up after a task-switch |
4137 |
++ * @rq: runqueue associated with task-switch |
4138 |
++ * @prev: the thread we just switched away from. |
4139 |
++ * |
4140 |
++ * finish_task_switch must be called after the context switch, paired |
4141 |
++ * with a prepare_task_switch call before the context switch. |
4142 |
++ * finish_task_switch will reconcile locking set up by prepare_task_switch, |
4143 |
++ * and do any other architecture-specific cleanup actions. |
4144 |
++ * |
4145 |
++ * Note that we may have delayed dropping an mm in context_switch(). If |
4146 |
++ * so, we finish that here outside of the runqueue lock. (Doing it |
4147 |
++ * with the lock held can cause deadlocks; see schedule() for |
4148 |
++ * details.) |
4149 |
++ * |
4150 |
++ * The context switch have flipped the stack from under us and restored the |
4151 |
++ * local variables which were saved when this task called schedule() in the |
4152 |
++ * past. prev == current is still correct but we need to recalculate this_rq |
4153 |
++ * because prev may have moved to another CPU. |
4154 |
++ */ |
4155 |
++static struct rq *finish_task_switch(struct task_struct *prev) |
4156 |
++ __releases(rq->lock) |
4157 |
++{ |
4158 |
++ struct rq *rq = this_rq(); |
4159 |
++ struct mm_struct *mm = rq->prev_mm; |
4160 |
++ unsigned int prev_state; |
4161 |
++ |
4162 |
++ /* |
4163 |
++ * The previous task will have left us with a preempt_count of 2 |
4164 |
++ * because it left us after: |
4165 |
++ * |
4166 |
++ * schedule() |
4167 |
++ * preempt_disable(); // 1 |
4168 |
++ * __schedule() |
4169 |
++ * raw_spin_lock_irq(&rq->lock) // 2 |
4170 |
++ * |
4171 |
++ * Also, see FORK_PREEMPT_COUNT. |
4172 |
++ */ |
4173 |
++ if (WARN_ONCE(preempt_count() != 2*PREEMPT_DISABLE_OFFSET, |
4174 |
++ "corrupted preempt_count: %s/%d/0x%x\n", |
4175 |
++ current->comm, current->pid, preempt_count())) |
4176 |
++ preempt_count_set(FORK_PREEMPT_COUNT); |
4177 |
++ |
4178 |
++ rq->prev_mm = NULL; |
4179 |
++ |
4180 |
++ /* |
4181 |
++ * A task struct has one reference for the use as "current". |
4182 |
++ * If a task dies, then it sets TASK_DEAD in tsk->state and calls |
4183 |
++ * schedule one last time. The schedule call will never return, and |
4184 |
++ * the scheduled task must drop that reference. |
4185 |
++ * |
4186 |
++ * We must observe prev->state before clearing prev->on_cpu (in |
4187 |
++ * finish_task), otherwise a concurrent wakeup can get prev |
4188 |
++ * running on another CPU and we could rave with its RUNNING -> DEAD |
4189 |
++ * transition, resulting in a double drop. |
4190 |
++ */ |
4191 |
++ prev_state = READ_ONCE(prev->__state); |
4192 |
++ vtime_task_switch(prev); |
4193 |
++ perf_event_task_sched_in(prev, current); |
4194 |
++ finish_task(prev); |
4195 |
++ tick_nohz_task_switch(); |
4196 |
++ finish_lock_switch(rq); |
4197 |
++ finish_arch_post_lock_switch(); |
4198 |
++ kcov_finish_switch(current); |
4199 |
++ /* |
4200 |
++ * kmap_local_sched_out() is invoked with rq::lock held and |
4201 |
++ * interrupts disabled. There is no requirement for that, but the |
4202 |
++ * sched out code does not have an interrupt enabled section. |
4203 |
++ * Restoring the maps on sched in does not require interrupts being |
4204 |
++ * disabled either. |
4205 |
++ */ |
4206 |
++ kmap_local_sched_in(); |
4207 |
++ |
4208 |
++ fire_sched_in_preempt_notifiers(current); |
4209 |
++ /* |
4210 |
++ * When switching through a kernel thread, the loop in |
4211 |
++ * membarrier_{private,global}_expedited() may have observed that |
4212 |
++ * kernel thread and not issued an IPI. It is therefore possible to |
4213 |
++ * schedule between user->kernel->user threads without passing though |
4214 |
++ * switch_mm(). Membarrier requires a barrier after storing to |
4215 |
++ * rq->curr, before returning to userspace, so provide them here: |
4216 |
++ * |
4217 |
++ * - a full memory barrier for {PRIVATE,GLOBAL}_EXPEDITED, implicitly |
4218 |
++ * provided by mmdrop(), |
4219 |
++ * - a sync_core for SYNC_CORE. |
4220 |
++ */ |
4221 |
++ if (mm) { |
4222 |
++ membarrier_mm_sync_core_before_usermode(mm); |
4223 |
++ mmdrop_sched(mm); |
4224 |
++ } |
4225 |
++ if (unlikely(prev_state == TASK_DEAD)) { |
4226 |
++ /* Task is done with its stack. */ |
4227 |
++ put_task_stack(prev); |
4228 |
++ |
4229 |
++ put_task_struct_rcu_user(prev); |
4230 |
++ } |
4231 |
++ |
4232 |
++ return rq; |
4233 |
++} |
4234 |
++ |
4235 |
++/** |
4236 |
++ * schedule_tail - first thing a freshly forked thread must call. |
4237 |
++ * @prev: the thread we just switched away from. |
4238 |
++ */ |
4239 |
++asmlinkage __visible void schedule_tail(struct task_struct *prev) |
4240 |
++ __releases(rq->lock) |
4241 |
++{ |
4242 |
++ /* |
4243 |
++ * New tasks start with FORK_PREEMPT_COUNT, see there and |
4244 |
++ * finish_task_switch() for details. |
4245 |
++ * |
4246 |
++ * finish_task_switch() will drop rq->lock() and lower preempt_count |
4247 |
++ * and the preempt_enable() will end up enabling preemption (on |
4248 |
++ * PREEMPT_COUNT kernels). |
4249 |
++ */ |
4250 |
++ |
4251 |
++ finish_task_switch(prev); |
4252 |
++ preempt_enable(); |
4253 |
++ |
4254 |
++ if (current->set_child_tid) |
4255 |
++ put_user(task_pid_vnr(current), current->set_child_tid); |
4256 |
++ |
4257 |
++ calculate_sigpending(); |
4258 |
++} |
4259 |
++ |
4260 |
++/* |
4261 |
++ * context_switch - switch to the new MM and the new thread's register state. |
4262 |
++ */ |
4263 |
++static __always_inline struct rq * |
4264 |
++context_switch(struct rq *rq, struct task_struct *prev, |
4265 |
++ struct task_struct *next) |
4266 |
++{ |
4267 |
++ prepare_task_switch(rq, prev, next); |
4268 |
++ |
4269 |
++ /* |
4270 |
++ * For paravirt, this is coupled with an exit in switch_to to |
4271 |
++ * combine the page table reload and the switch backend into |
4272 |
++ * one hypercall. |
4273 |
++ */ |
4274 |
++ arch_start_context_switch(prev); |
4275 |
++ |
4276 |
++ /* |
4277 |
++ * kernel -> kernel lazy + transfer active |
4278 |
++ * user -> kernel lazy + mmgrab() active |
4279 |
++ * |
4280 |
++ * kernel -> user switch + mmdrop() active |
4281 |
++ * user -> user switch |
4282 |
++ */ |
4283 |
++ if (!next->mm) { // to kernel |
4284 |
++ enter_lazy_tlb(prev->active_mm, next); |
4285 |
++ |
4286 |
++ next->active_mm = prev->active_mm; |
4287 |
++ if (prev->mm) // from user |
4288 |
++ mmgrab(prev->active_mm); |
4289 |
++ else |
4290 |
++ prev->active_mm = NULL; |
4291 |
++ } else { // to user |
4292 |
++ membarrier_switch_mm(rq, prev->active_mm, next->mm); |
4293 |
++ /* |
4294 |
++ * sys_membarrier() requires an smp_mb() between setting |
4295 |
++ * rq->curr / membarrier_switch_mm() and returning to userspace. |
4296 |
++ * |
4297 |
++ * The below provides this either through switch_mm(), or in |
4298 |
++ * case 'prev->active_mm == next->mm' through |
4299 |
++ * finish_task_switch()'s mmdrop(). |
4300 |
++ */ |
4301 |
++ switch_mm_irqs_off(prev->active_mm, next->mm, next); |
4302 |
++ |
4303 |
++ if (!prev->mm) { // from kernel |
4304 |
++ /* will mmdrop() in finish_task_switch(). */ |
4305 |
++ rq->prev_mm = prev->active_mm; |
4306 |
++ prev->active_mm = NULL; |
4307 |
++ } |
4308 |
++ } |
4309 |
++ |
4310 |
++ prepare_lock_switch(rq, next); |
4311 |
++ |
4312 |
++ /* Here we just switch the register state and the stack. */ |
4313 |
++ switch_to(prev, next, prev); |
4314 |
++ barrier(); |
4315 |
++ |
4316 |
++ return finish_task_switch(prev); |
4317 |
++} |
4318 |
++ |
4319 |
++/* |
4320 |
++ * nr_running, nr_uninterruptible and nr_context_switches: |
4321 |
++ * |
4322 |
++ * externally visible scheduler statistics: current number of runnable |
4323 |
++ * threads, total number of context switches performed since bootup. |
4324 |
++ */ |
4325 |
++unsigned int nr_running(void) |
4326 |
++{ |
4327 |
++ unsigned int i, sum = 0; |
4328 |
++ |
4329 |
++ for_each_online_cpu(i) |
4330 |
++ sum += cpu_rq(i)->nr_running; |
4331 |
++ |
4332 |
++ return sum; |
4333 |
++} |
4334 |
++ |
4335 |
++/* |
4336 |
++ * Check if only the current task is running on the CPU. |
4337 |
++ * |
4338 |
++ * Caution: this function does not check that the caller has disabled |
4339 |
++ * preemption, thus the result might have a time-of-check-to-time-of-use |
4340 |
++ * race. The caller is responsible to use it correctly, for example: |
4341 |
++ * |
4342 |
++ * - from a non-preemptible section (of course) |
4343 |
++ * |
4344 |
++ * - from a thread that is bound to a single CPU |
4345 |
++ * |
4346 |
++ * - in a loop with very short iterations (e.g. a polling loop) |
4347 |
++ */ |
4348 |
++bool single_task_running(void) |
4349 |
++{ |
4350 |
++ return raw_rq()->nr_running == 1; |
4351 |
++} |
4352 |
++EXPORT_SYMBOL(single_task_running); |
4353 |
++ |
4354 |
++unsigned long long nr_context_switches(void) |
4355 |
++{ |
4356 |
++ int i; |
4357 |
++ unsigned long long sum = 0; |
4358 |
++ |
4359 |
++ for_each_possible_cpu(i) |
4360 |
++ sum += cpu_rq(i)->nr_switches; |
4361 |
++ |
4362 |
++ return sum; |
4363 |
++} |
4364 |
++ |
4365 |
++/* |
4366 |
++ * Consumers of these two interfaces, like for example the cpuidle menu |
4367 |
++ * governor, are using nonsensical data. Preferring shallow idle state selection |
4368 |
++ * for a CPU that has IO-wait which might not even end up running the task when |
4369 |
++ * it does become runnable. |
4370 |
++ */ |
4371 |
++ |
4372 |
++unsigned int nr_iowait_cpu(int cpu) |
4373 |
++{ |
4374 |
++ return atomic_read(&cpu_rq(cpu)->nr_iowait); |
4375 |
++} |
4376 |
++ |
4377 |
++/* |
4378 |
++ * IO-wait accounting, and how it's mostly bollocks (on SMP). |
4379 |
++ * |
4380 |
++ * The idea behind IO-wait account is to account the idle time that we could |
4381 |
++ * have spend running if it were not for IO. That is, if we were to improve the |
4382 |
++ * storage performance, we'd have a proportional reduction in IO-wait time. |
4383 |
++ * |
4384 |
++ * This all works nicely on UP, where, when a task blocks on IO, we account |
4385 |
++ * idle time as IO-wait, because if the storage were faster, it could've been |
4386 |
++ * running and we'd not be idle. |
4387 |
++ * |
4388 |
++ * This has been extended to SMP, by doing the same for each CPU. This however |
4389 |
++ * is broken. |
4390 |
++ * |
4391 |
++ * Imagine for instance the case where two tasks block on one CPU, only the one |
4392 |
++ * CPU will have IO-wait accounted, while the other has regular idle. Even |
4393 |
++ * though, if the storage were faster, both could've ran at the same time, |
4394 |
++ * utilising both CPUs. |
4395 |
++ * |
4396 |
++ * This means, that when looking globally, the current IO-wait accounting on |
4397 |
++ * SMP is a lower bound, by reason of under accounting. |
4398 |
++ * |
4399 |
++ * Worse, since the numbers are provided per CPU, they are sometimes |
4400 |
++ * interpreted per CPU, and that is nonsensical. A blocked task isn't strictly |
4401 |
++ * associated with any one particular CPU, it can wake to another CPU than it |
4402 |
++ * blocked on. This means the per CPU IO-wait number is meaningless. |
4403 |
++ * |
4404 |
++ * Task CPU affinities can make all that even more 'interesting'. |
4405 |
++ */ |
4406 |
++ |
4407 |
++unsigned int nr_iowait(void) |
4408 |
++{ |
4409 |
++ unsigned int i, sum = 0; |
4410 |
++ |
4411 |
++ for_each_possible_cpu(i) |
4412 |
++ sum += nr_iowait_cpu(i); |
4413 |
++ |
4414 |
++ return sum; |
4415 |
++} |
4416 |
++ |
4417 |
++#ifdef CONFIG_SMP |
4418 |
++ |
4419 |
++/* |
4420 |
++ * sched_exec - execve() is a valuable balancing opportunity, because at |
4421 |
++ * this point the task has the smallest effective memory and cache |
4422 |
++ * footprint. |
4423 |
++ */ |
4424 |
++void sched_exec(void) |
4425 |
++{ |
4426 |
++} |
4427 |
++ |
4428 |
++#endif |
4429 |
++ |
4430 |
++DEFINE_PER_CPU(struct kernel_stat, kstat); |
4431 |
++DEFINE_PER_CPU(struct kernel_cpustat, kernel_cpustat); |
4432 |
++ |
4433 |
++EXPORT_PER_CPU_SYMBOL(kstat); |
4434 |
++EXPORT_PER_CPU_SYMBOL(kernel_cpustat); |
4435 |
++ |
4436 |
++static inline void update_curr(struct rq *rq, struct task_struct *p) |
4437 |
++{ |
4438 |
++ s64 ns = rq->clock_task - p->last_ran; |
4439 |
++ |
4440 |
++ p->sched_time += ns; |
4441 |
++ cgroup_account_cputime(p, ns); |
4442 |
++ account_group_exec_runtime(p, ns); |
4443 |
++ |
4444 |
++ p->time_slice -= ns; |
4445 |
++ p->last_ran = rq->clock_task; |
4446 |
++} |
4447 |
++ |
4448 |
++/* |
4449 |
++ * Return accounted runtime for the task. |
4450 |
++ * Return separately the current's pending runtime that have not been |
4451 |
++ * accounted yet. |
4452 |
++ */ |
4453 |
++unsigned long long task_sched_runtime(struct task_struct *p) |
4454 |
++{ |
4455 |
++ unsigned long flags; |
4456 |
++ struct rq *rq; |
4457 |
++ raw_spinlock_t *lock; |
4458 |
++ u64 ns; |
4459 |
++ |
4460 |
++#if defined(CONFIG_64BIT) && defined(CONFIG_SMP) |
4461 |
++ /* |
4462 |
++ * 64-bit doesn't need locks to atomically read a 64-bit value. |
4463 |
++ * So we have a optimization chance when the task's delta_exec is 0. |
4464 |
++ * Reading ->on_cpu is racy, but this is ok. |
4465 |
++ * |
4466 |
++ * If we race with it leaving CPU, we'll take a lock. So we're correct. |
4467 |
++ * If we race with it entering CPU, unaccounted time is 0. This is |
4468 |
++ * indistinguishable from the read occurring a few cycles earlier. |
4469 |
++ * If we see ->on_cpu without ->on_rq, the task is leaving, and has |
4470 |
++ * been accounted, so we're correct here as well. |
4471 |
++ */ |
4472 |
++ if (!p->on_cpu || !task_on_rq_queued(p)) |
4473 |
++ return tsk_seruntime(p); |
4474 |
++#endif |
4475 |
++ |
4476 |
++ rq = task_access_lock_irqsave(p, &lock, &flags); |
4477 |
++ /* |
4478 |
++ * Must be ->curr _and_ ->on_rq. If dequeued, we would |
4479 |
++ * project cycles that may never be accounted to this |
4480 |
++ * thread, breaking clock_gettime(). |
4481 |
++ */ |
4482 |
++ if (p == rq->curr && task_on_rq_queued(p)) { |
4483 |
++ update_rq_clock(rq); |
4484 |
++ update_curr(rq, p); |
4485 |
++ } |
4486 |
++ ns = tsk_seruntime(p); |
4487 |
++ task_access_unlock_irqrestore(p, lock, &flags); |
4488 |
++ |
4489 |
++ return ns; |
4490 |
++} |
4491 |
++ |
4492 |
++/* This manages tasks that have run out of timeslice during a scheduler_tick */ |
4493 |
++static inline void scheduler_task_tick(struct rq *rq) |
4494 |
++{ |
4495 |
++ struct task_struct *p = rq->curr; |
4496 |
++ |
4497 |
++ if (is_idle_task(p)) |
4498 |
++ return; |
4499 |
++ |
4500 |
++ update_curr(rq, p); |
4501 |
++ cpufreq_update_util(rq, 0); |
4502 |
++ |
4503 |
++ /* |
4504 |
++ * Tasks have less than RESCHED_NS of time slice left they will be |
4505 |
++ * rescheduled. |
4506 |
++ */ |
4507 |
++ if (p->time_slice >= RESCHED_NS) |
4508 |
++ return; |
4509 |
++ set_tsk_need_resched(p); |
4510 |
++ set_preempt_need_resched(); |
4511 |
++} |
4512 |
++ |
4513 |
++#ifdef CONFIG_SCHED_DEBUG |
4514 |
++static u64 cpu_resched_latency(struct rq *rq) |
4515 |
++{ |
4516 |
++ int latency_warn_ms = READ_ONCE(sysctl_resched_latency_warn_ms); |
4517 |
++ u64 resched_latency, now = rq_clock(rq); |
4518 |
++ static bool warned_once; |
4519 |
++ |
4520 |
++ if (sysctl_resched_latency_warn_once && warned_once) |
4521 |
++ return 0; |
4522 |
++ |
4523 |
++ if (!need_resched() || !latency_warn_ms) |
4524 |
++ return 0; |
4525 |
++ |
4526 |
++ if (system_state == SYSTEM_BOOTING) |
4527 |
++ return 0; |
4528 |
++ |
4529 |
++ if (!rq->last_seen_need_resched_ns) { |
4530 |
++ rq->last_seen_need_resched_ns = now; |
4531 |
++ rq->ticks_without_resched = 0; |
4532 |
++ return 0; |
4533 |
++ } |
4534 |
++ |
4535 |
++ rq->ticks_without_resched++; |
4536 |
++ resched_latency = now - rq->last_seen_need_resched_ns; |
4537 |
++ if (resched_latency <= latency_warn_ms * NSEC_PER_MSEC) |
4538 |
++ return 0; |
4539 |
++ |
4540 |
++ warned_once = true; |
4541 |
++ |
4542 |
++ return resched_latency; |
4543 |
++} |
4544 |
++ |
4545 |
++static int __init setup_resched_latency_warn_ms(char *str) |
4546 |
++{ |
4547 |
++ long val; |
4548 |
++ |
4549 |
++ if ((kstrtol(str, 0, &val))) { |
4550 |
++ pr_warn("Unable to set resched_latency_warn_ms\n"); |
4551 |
++ return 1; |
4552 |
++ } |
4553 |
++ |
4554 |
++ sysctl_resched_latency_warn_ms = val; |
4555 |
++ return 1; |
4556 |
++} |
4557 |
++__setup("resched_latency_warn_ms=", setup_resched_latency_warn_ms); |
4558 |
++#else |
4559 |
++static inline u64 cpu_resched_latency(struct rq *rq) { return 0; } |
4560 |
++#endif /* CONFIG_SCHED_DEBUG */ |
4561 |
++ |
4562 |
++/* |
4563 |
++ * This function gets called by the timer code, with HZ frequency. |
4564 |
++ * We call it with interrupts disabled. |
4565 |
++ */ |
4566 |
++void scheduler_tick(void) |
4567 |
++{ |
4568 |
++ int cpu __maybe_unused = smp_processor_id(); |
4569 |
++ struct rq *rq = cpu_rq(cpu); |
4570 |
++ u64 resched_latency; |
4571 |
++ |
4572 |
++ arch_scale_freq_tick(); |
4573 |
++ sched_clock_tick(); |
4574 |
++ |
4575 |
++ raw_spin_lock(&rq->lock); |
4576 |
++ update_rq_clock(rq); |
4577 |
++ |
4578 |
++ scheduler_task_tick(rq); |
4579 |
++ if (sched_feat(LATENCY_WARN)) |
4580 |
++ resched_latency = cpu_resched_latency(rq); |
4581 |
++ calc_global_load_tick(rq); |
4582 |
++ |
4583 |
++ rq->last_tick = rq->clock; |
4584 |
++ raw_spin_unlock(&rq->lock); |
4585 |
++ |
4586 |
++ if (sched_feat(LATENCY_WARN) && resched_latency) |
4587 |
++ resched_latency_warn(cpu, resched_latency); |
4588 |
++ |
4589 |
++ perf_event_task_tick(); |
4590 |
++} |
4591 |
++ |
4592 |
++#ifdef CONFIG_SCHED_SMT |
4593 |
++static inline int sg_balance_cpu_stop(void *data) |
4594 |
++{ |
4595 |
++ struct rq *rq = this_rq(); |
4596 |
++ struct task_struct *p = data; |
4597 |
++ cpumask_t tmp; |
4598 |
++ unsigned long flags; |
4599 |
++ |
4600 |
++ local_irq_save(flags); |
4601 |
++ |
4602 |
++ raw_spin_lock(&p->pi_lock); |
4603 |
++ raw_spin_lock(&rq->lock); |
4604 |
++ |
4605 |
++ rq->active_balance = 0; |
4606 |
++ /* _something_ may have changed the task, double check again */ |
4607 |
++ if (task_on_rq_queued(p) && task_rq(p) == rq && |
4608 |
++ cpumask_and(&tmp, p->cpus_ptr, &sched_sg_idle_mask) && |
4609 |
++ !is_migration_disabled(p)) { |
4610 |
++ int cpu = cpu_of(rq); |
4611 |
++ int dcpu = __best_mask_cpu(&tmp, per_cpu(sched_cpu_llc_mask, cpu)); |
4612 |
++ rq = move_queued_task(rq, p, dcpu); |
4613 |
++ } |
4614 |
++ |
4615 |
++ raw_spin_unlock(&rq->lock); |
4616 |
++ raw_spin_unlock(&p->pi_lock); |
4617 |
++ |
4618 |
++ local_irq_restore(flags); |
4619 |
++ |
4620 |
++ return 0; |
4621 |
++} |
4622 |
++ |
4623 |
++/* sg_balance_trigger - trigger slibing group balance for @cpu */ |
4624 |
++static inline int sg_balance_trigger(const int cpu) |
4625 |
++{ |
4626 |
++ struct rq *rq= cpu_rq(cpu); |
4627 |
++ unsigned long flags; |
4628 |
++ struct task_struct *curr; |
4629 |
++ int res; |
4630 |
++ |
4631 |
++ if (!raw_spin_trylock_irqsave(&rq->lock, flags)) |
4632 |
++ return 0; |
4633 |
++ curr = rq->curr; |
4634 |
++ res = (!is_idle_task(curr)) && (1 == rq->nr_running) &&\ |
4635 |
++ cpumask_intersects(curr->cpus_ptr, &sched_sg_idle_mask) &&\ |
4636 |
++ !is_migration_disabled(curr) && (!rq->active_balance); |
4637 |
++ |
4638 |
++ if (res) |
4639 |
++ rq->active_balance = 1; |
4640 |
++ |
4641 |
++ raw_spin_unlock_irqrestore(&rq->lock, flags); |
4642 |
++ |
4643 |
++ if (res) |
4644 |
++ stop_one_cpu_nowait(cpu, sg_balance_cpu_stop, curr, |
4645 |
++ &rq->active_balance_work); |
4646 |
++ return res; |
4647 |
++} |
4648 |
++ |
4649 |
++/* |
4650 |
++ * sg_balance - slibing group balance check for run queue @rq |
4651 |
++ */ |
4652 |
++static inline void sg_balance(struct rq *rq) |
4653 |
++{ |
4654 |
++ cpumask_t chk; |
4655 |
++ int cpu = cpu_of(rq); |
4656 |
++ |
4657 |
++ /* exit when cpu is offline */ |
4658 |
++ if (unlikely(!rq->online)) |
4659 |
++ return; |
4660 |
++ |
4661 |
++ /* |
4662 |
++ * Only cpu in slibing idle group will do the checking and then |
4663 |
++ * find potential cpus which can migrate the current running task |
4664 |
++ */ |
4665 |
++ if (cpumask_test_cpu(cpu, &sched_sg_idle_mask) && |
4666 |
++ cpumask_andnot(&chk, cpu_online_mask, sched_rq_watermark) && |
4667 |
++ cpumask_andnot(&chk, &chk, &sched_rq_pending_mask)) { |
4668 |
++ int i; |
4669 |
++ |
4670 |
++ for_each_cpu_wrap(i, &chk, cpu) { |
4671 |
++ if (cpumask_subset(cpu_smt_mask(i), &chk) && |
4672 |
++ sg_balance_trigger(i)) |
4673 |
++ return; |
4674 |
++ } |
4675 |
++ } |
4676 |
++} |
4677 |
++#endif /* CONFIG_SCHED_SMT */ |
4678 |
++ |
4679 |
++#ifdef CONFIG_NO_HZ_FULL |
4680 |
++ |
4681 |
++struct tick_work { |
4682 |
++ int cpu; |
4683 |
++ atomic_t state; |
4684 |
++ struct delayed_work work; |
4685 |
++}; |
4686 |
++/* Values for ->state, see diagram below. */ |
4687 |
++#define TICK_SCHED_REMOTE_OFFLINE 0 |
4688 |
++#define TICK_SCHED_REMOTE_OFFLINING 1 |
4689 |
++#define TICK_SCHED_REMOTE_RUNNING 2 |
4690 |
++ |
4691 |
++/* |
4692 |
++ * State diagram for ->state: |
4693 |
++ * |
4694 |
++ * |
4695 |
++ * TICK_SCHED_REMOTE_OFFLINE |
4696 |
++ * | ^ |
4697 |
++ * | | |
4698 |
++ * | | sched_tick_remote() |
4699 |
++ * | | |
4700 |
++ * | | |
4701 |
++ * +--TICK_SCHED_REMOTE_OFFLINING |
4702 |
++ * | ^ |
4703 |
++ * | | |
4704 |
++ * sched_tick_start() | | sched_tick_stop() |
4705 |
++ * | | |
4706 |
++ * V | |
4707 |
++ * TICK_SCHED_REMOTE_RUNNING |
4708 |
++ * |
4709 |
++ * |
4710 |
++ * Other transitions get WARN_ON_ONCE(), except that sched_tick_remote() |
4711 |
++ * and sched_tick_start() are happy to leave the state in RUNNING. |
4712 |
++ */ |
4713 |
++ |
4714 |
++static struct tick_work __percpu *tick_work_cpu; |
4715 |
++ |
4716 |
++static void sched_tick_remote(struct work_struct *work) |
4717 |
++{ |
4718 |
++ struct delayed_work *dwork = to_delayed_work(work); |
4719 |
++ struct tick_work *twork = container_of(dwork, struct tick_work, work); |
4720 |
++ int cpu = twork->cpu; |
4721 |
++ struct rq *rq = cpu_rq(cpu); |
4722 |
++ struct task_struct *curr; |
4723 |
++ unsigned long flags; |
4724 |
++ u64 delta; |
4725 |
++ int os; |
4726 |
++ |
4727 |
++ /* |
4728 |
++ * Handle the tick only if it appears the remote CPU is running in full |
4729 |
++ * dynticks mode. The check is racy by nature, but missing a tick or |
4730 |
++ * having one too much is no big deal because the scheduler tick updates |
4731 |
++ * statistics and checks timeslices in a time-independent way, regardless |
4732 |
++ * of when exactly it is running. |
4733 |
++ */ |
4734 |
++ if (!tick_nohz_tick_stopped_cpu(cpu)) |
4735 |
++ goto out_requeue; |
4736 |
++ |
4737 |
++ raw_spin_lock_irqsave(&rq->lock, flags); |
4738 |
++ curr = rq->curr; |
4739 |
++ if (cpu_is_offline(cpu)) |
4740 |
++ goto out_unlock; |
4741 |
++ |
4742 |
++ update_rq_clock(rq); |
4743 |
++ if (!is_idle_task(curr)) { |
4744 |
++ /* |
4745 |
++ * Make sure the next tick runs within a reasonable |
4746 |
++ * amount of time. |
4747 |
++ */ |
4748 |
++ delta = rq_clock_task(rq) - curr->last_ran; |
4749 |
++ WARN_ON_ONCE(delta > (u64)NSEC_PER_SEC * 3); |
4750 |
++ } |
4751 |
++ scheduler_task_tick(rq); |
4752 |
++ |
4753 |
++ calc_load_nohz_remote(rq); |
4754 |
++out_unlock: |
4755 |
++ raw_spin_unlock_irqrestore(&rq->lock, flags); |
4756 |
++ |
4757 |
++out_requeue: |
4758 |
++ /* |
4759 |
++ * Run the remote tick once per second (1Hz). This arbitrary |
4760 |
++ * frequency is large enough to avoid overload but short enough |
4761 |
++ * to keep scheduler internal stats reasonably up to date. But |
4762 |
++ * first update state to reflect hotplug activity if required. |
4763 |
++ */ |
4764 |
++ os = atomic_fetch_add_unless(&twork->state, -1, TICK_SCHED_REMOTE_RUNNING); |
4765 |
++ WARN_ON_ONCE(os == TICK_SCHED_REMOTE_OFFLINE); |
4766 |
++ if (os == TICK_SCHED_REMOTE_RUNNING) |
4767 |
++ queue_delayed_work(system_unbound_wq, dwork, HZ); |
4768 |
++} |
4769 |
++ |
4770 |
++static void sched_tick_start(int cpu) |
4771 |
++{ |
4772 |
++ int os; |
4773 |
++ struct tick_work *twork; |
4774 |
++ |
4775 |
++ if (housekeeping_cpu(cpu, HK_TYPE_TICK)) |
4776 |
++ return; |
4777 |
++ |
4778 |
++ WARN_ON_ONCE(!tick_work_cpu); |
4779 |
++ |
4780 |
++ twork = per_cpu_ptr(tick_work_cpu, cpu); |
4781 |
++ os = atomic_xchg(&twork->state, TICK_SCHED_REMOTE_RUNNING); |
4782 |
++ WARN_ON_ONCE(os == TICK_SCHED_REMOTE_RUNNING); |
4783 |
++ if (os == TICK_SCHED_REMOTE_OFFLINE) { |
4784 |
++ twork->cpu = cpu; |
4785 |
++ INIT_DELAYED_WORK(&twork->work, sched_tick_remote); |
4786 |
++ queue_delayed_work(system_unbound_wq, &twork->work, HZ); |
4787 |
++ } |
4788 |
++} |
4789 |
++ |
4790 |
++#ifdef CONFIG_HOTPLUG_CPU |
4791 |
++static void sched_tick_stop(int cpu) |
4792 |
++{ |
4793 |
++ struct tick_work *twork; |
4794 |
++ |
4795 |
++ if (housekeeping_cpu(cpu, HK_TYPE_TICK)) |
4796 |
++ return; |
4797 |
++ |
4798 |
++ WARN_ON_ONCE(!tick_work_cpu); |
4799 |
++ |
4800 |
++ twork = per_cpu_ptr(tick_work_cpu, cpu); |
4801 |
++ cancel_delayed_work_sync(&twork->work); |
4802 |
++} |
4803 |
++#endif /* CONFIG_HOTPLUG_CPU */ |
4804 |
++ |
4805 |
++int __init sched_tick_offload_init(void) |
4806 |
++{ |
4807 |
++ tick_work_cpu = alloc_percpu(struct tick_work); |
4808 |
++ BUG_ON(!tick_work_cpu); |
4809 |
++ return 0; |
4810 |
++} |
4811 |
++ |
4812 |
++#else /* !CONFIG_NO_HZ_FULL */ |
4813 |
++static inline void sched_tick_start(int cpu) { } |
4814 |
++static inline void sched_tick_stop(int cpu) { } |
4815 |
++#endif |
4816 |
++ |
4817 |
++#if defined(CONFIG_PREEMPTION) && (defined(CONFIG_DEBUG_PREEMPT) || \ |
4818 |
++ defined(CONFIG_PREEMPT_TRACER)) |
4819 |
++/* |
4820 |
++ * If the value passed in is equal to the current preempt count |
4821 |
++ * then we just disabled preemption. Start timing the latency. |
4822 |
++ */ |
4823 |
++static inline void preempt_latency_start(int val) |
4824 |
++{ |
4825 |
++ if (preempt_count() == val) { |
4826 |
++ unsigned long ip = get_lock_parent_ip(); |
4827 |
++#ifdef CONFIG_DEBUG_PREEMPT |
4828 |
++ current->preempt_disable_ip = ip; |
4829 |
++#endif |
4830 |
++ trace_preempt_off(CALLER_ADDR0, ip); |
4831 |
++ } |
4832 |
++} |
4833 |
++ |
4834 |
++void preempt_count_add(int val) |
4835 |
++{ |
4836 |
++#ifdef CONFIG_DEBUG_PREEMPT |
4837 |
++ /* |
4838 |
++ * Underflow? |
4839 |
++ */ |
4840 |
++ if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) |
4841 |
++ return; |
4842 |
++#endif |
4843 |
++ __preempt_count_add(val); |
4844 |
++#ifdef CONFIG_DEBUG_PREEMPT |
4845 |
++ /* |
4846 |
++ * Spinlock count overflowing soon? |
4847 |
++ */ |
4848 |
++ DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= |
4849 |
++ PREEMPT_MASK - 10); |
4850 |
++#endif |
4851 |
++ preempt_latency_start(val); |
4852 |
++} |
4853 |
++EXPORT_SYMBOL(preempt_count_add); |
4854 |
++NOKPROBE_SYMBOL(preempt_count_add); |
4855 |
++ |
4856 |
++/* |
4857 |
++ * If the value passed in equals to the current preempt count |
4858 |
++ * then we just enabled preemption. Stop timing the latency. |
4859 |
++ */ |
4860 |
++static inline void preempt_latency_stop(int val) |
4861 |
++{ |
4862 |
++ if (preempt_count() == val) |
4863 |
++ trace_preempt_on(CALLER_ADDR0, get_lock_parent_ip()); |
4864 |
++} |
4865 |
++ |
4866 |
++void preempt_count_sub(int val) |
4867 |
++{ |
4868 |
++#ifdef CONFIG_DEBUG_PREEMPT |
4869 |
++ /* |
4870 |
++ * Underflow? |
4871 |
++ */ |
4872 |
++ if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) |
4873 |
++ return; |
4874 |
++ /* |
4875 |
++ * Is the spinlock portion underflowing? |
4876 |
++ */ |
4877 |
++ if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && |
4878 |
++ !(preempt_count() & PREEMPT_MASK))) |
4879 |
++ return; |
4880 |
++#endif |
4881 |
++ |
4882 |
++ preempt_latency_stop(val); |
4883 |
++ __preempt_count_sub(val); |
4884 |
++} |
4885 |
++EXPORT_SYMBOL(preempt_count_sub); |
4886 |
++NOKPROBE_SYMBOL(preempt_count_sub); |
4887 |
++ |
4888 |
++#else |
4889 |
++static inline void preempt_latency_start(int val) { } |
4890 |
++static inline void preempt_latency_stop(int val) { } |
4891 |
++#endif |
4892 |
++ |
4893 |
++static inline unsigned long get_preempt_disable_ip(struct task_struct *p) |
4894 |
++{ |
4895 |
++#ifdef CONFIG_DEBUG_PREEMPT |
4896 |
++ return p->preempt_disable_ip; |
4897 |
++#else |
4898 |
++ return 0; |
4899 |
++#endif |
4900 |
++} |
4901 |
++ |
4902 |
++/* |
4903 |
++ * Print scheduling while atomic bug: |
4904 |
++ */ |
4905 |
++static noinline void __schedule_bug(struct task_struct *prev) |
4906 |
++{ |
4907 |
++ /* Save this before calling printk(), since that will clobber it */ |
4908 |
++ unsigned long preempt_disable_ip = get_preempt_disable_ip(current); |
4909 |
++ |
4910 |
++ if (oops_in_progress) |
4911 |
++ return; |
4912 |
++ |
4913 |
++ printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", |
4914 |
++ prev->comm, prev->pid, preempt_count()); |
4915 |
++ |
4916 |
++ debug_show_held_locks(prev); |
4917 |
++ print_modules(); |
4918 |
++ if (irqs_disabled()) |
4919 |
++ print_irqtrace_events(prev); |
4920 |
++ if (IS_ENABLED(CONFIG_DEBUG_PREEMPT) |
4921 |
++ && in_atomic_preempt_off()) { |
4922 |
++ pr_err("Preemption disabled at:"); |
4923 |
++ print_ip_sym(KERN_ERR, preempt_disable_ip); |
4924 |
++ } |
4925 |
++ if (panic_on_warn) |
4926 |
++ panic("scheduling while atomic\n"); |
4927 |
++ |
4928 |
++ dump_stack(); |
4929 |
++ add_taint(TAINT_WARN, LOCKDEP_STILL_OK); |
4930 |
++} |
4931 |
++ |
4932 |
++/* |
4933 |
++ * Various schedule()-time debugging checks and statistics: |
4934 |
++ */ |
4935 |
++static inline void schedule_debug(struct task_struct *prev, bool preempt) |
4936 |
++{ |
4937 |
++#ifdef CONFIG_SCHED_STACK_END_CHECK |
4938 |
++ if (task_stack_end_corrupted(prev)) |
4939 |
++ panic("corrupted stack end detected inside scheduler\n"); |
4940 |
++ |
4941 |
++ if (task_scs_end_corrupted(prev)) |
4942 |
++ panic("corrupted shadow stack detected inside scheduler\n"); |
4943 |
++#endif |
4944 |
++ |
4945 |
++#ifdef CONFIG_DEBUG_ATOMIC_SLEEP |
4946 |
++ if (!preempt && READ_ONCE(prev->__state) && prev->non_block_count) { |
4947 |
++ printk(KERN_ERR "BUG: scheduling in a non-blocking section: %s/%d/%i\n", |
4948 |
++ prev->comm, prev->pid, prev->non_block_count); |
4949 |
++ dump_stack(); |
4950 |
++ add_taint(TAINT_WARN, LOCKDEP_STILL_OK); |
4951 |
++ } |
4952 |
++#endif |
4953 |
++ |
4954 |
++ if (unlikely(in_atomic_preempt_off())) { |
4955 |
++ __schedule_bug(prev); |
4956 |
++ preempt_count_set(PREEMPT_DISABLED); |
4957 |
++ } |
4958 |
++ rcu_sleep_check(); |
4959 |
++ SCHED_WARN_ON(ct_state() == CONTEXT_USER); |
4960 |
++ |
4961 |
++ profile_hit(SCHED_PROFILING, __builtin_return_address(0)); |
4962 |
++ |
4963 |
++ schedstat_inc(this_rq()->sched_count); |
4964 |
++} |
4965 |
++ |
4966 |
++/* |
4967 |
++ * Compile time debug macro |
4968 |
++ * #define ALT_SCHED_DEBUG |
4969 |
++ */ |
4970 |
++ |
4971 |
++#ifdef ALT_SCHED_DEBUG |
4972 |
++void alt_sched_debug(void) |
4973 |
++{ |
4974 |
++ printk(KERN_INFO "sched: pending: 0x%04lx, idle: 0x%04lx, sg_idle: 0x%04lx\n", |
4975 |
++ sched_rq_pending_mask.bits[0], |
4976 |
++ sched_rq_watermark[0].bits[0], |
4977 |
++ sched_sg_idle_mask.bits[0]); |
4978 |
++} |
4979 |
++#else |
4980 |
++inline void alt_sched_debug(void) {} |
4981 |
++#endif |
4982 |
++ |
4983 |
++#ifdef CONFIG_SMP |
4984 |
++ |
4985 |
++#define SCHED_RQ_NR_MIGRATION (32U) |
4986 |
++/* |
4987 |
++ * Migrate pending tasks in @rq to @dest_cpu |
4988 |
++ * Will try to migrate mininal of half of @rq nr_running tasks and |
4989 |
++ * SCHED_RQ_NR_MIGRATION to @dest_cpu |
4990 |
++ */ |
4991 |
++static inline int |
4992 |
++migrate_pending_tasks(struct rq *rq, struct rq *dest_rq, const int dest_cpu) |
4993 |
++{ |
4994 |
++ struct task_struct *p, *skip = rq->curr; |
4995 |
++ int nr_migrated = 0; |
4996 |
++ int nr_tries = min(rq->nr_running / 2, SCHED_RQ_NR_MIGRATION); |
4997 |
++ |
4998 |
++ while (skip != rq->idle && nr_tries && |
4999 |
++ (p = sched_rq_next_task(skip, rq)) != rq->idle) { |
5000 |
++ skip = sched_rq_next_task(p, rq); |
5001 |
++ if (cpumask_test_cpu(dest_cpu, p->cpus_ptr)) { |
5002 |
++ __SCHED_DEQUEUE_TASK(p, rq, 0); |
5003 |
++ set_task_cpu(p, dest_cpu); |
5004 |
++ sched_task_sanity_check(p, dest_rq); |
5005 |
++ __SCHED_ENQUEUE_TASK(p, dest_rq, 0); |
5006 |
++ nr_migrated++; |
5007 |
++ } |
5008 |
++ nr_tries--; |
5009 |
++ } |
5010 |
++ |
5011 |
++ return nr_migrated; |
5012 |
++} |
5013 |
++ |
5014 |
++static inline int take_other_rq_tasks(struct rq *rq, int cpu) |
5015 |
++{ |
5016 |
++ struct cpumask *topo_mask, *end_mask; |
5017 |
++ |
5018 |
++ if (unlikely(!rq->online)) |
5019 |
++ return 0; |
5020 |
++ |
5021 |
++ if (cpumask_empty(&sched_rq_pending_mask)) |
5022 |
++ return 0; |
5023 |
++ |
5024 |
++ topo_mask = per_cpu(sched_cpu_topo_masks, cpu) + 1; |
5025 |
++ end_mask = per_cpu(sched_cpu_topo_end_mask, cpu); |
5026 |
++ do { |
5027 |
++ int i; |
5028 |
++ for_each_cpu_and(i, &sched_rq_pending_mask, topo_mask) { |
5029 |
++ int nr_migrated; |
5030 |
++ struct rq *src_rq; |
5031 |
++ |
5032 |
++ src_rq = cpu_rq(i); |
5033 |
++ if (!do_raw_spin_trylock(&src_rq->lock)) |
5034 |
++ continue; |
5035 |
++ spin_acquire(&src_rq->lock.dep_map, |
5036 |
++ SINGLE_DEPTH_NESTING, 1, _RET_IP_); |
5037 |
++ |
5038 |
++ if ((nr_migrated = migrate_pending_tasks(src_rq, rq, cpu))) { |
5039 |
++ src_rq->nr_running -= nr_migrated; |
5040 |
++ if (src_rq->nr_running < 2) |
5041 |
++ cpumask_clear_cpu(i, &sched_rq_pending_mask); |
5042 |
++ |
5043 |
++ rq->nr_running += nr_migrated; |
5044 |
++ if (rq->nr_running > 1) |
5045 |
++ cpumask_set_cpu(cpu, &sched_rq_pending_mask); |
5046 |
++ |
5047 |
++ cpufreq_update_util(rq, 0); |
5048 |
++ |
5049 |
++ spin_release(&src_rq->lock.dep_map, _RET_IP_); |
5050 |
++ do_raw_spin_unlock(&src_rq->lock); |
5051 |
++ |
5052 |
++ return 1; |
5053 |
++ } |
5054 |
++ |
5055 |
++ spin_release(&src_rq->lock.dep_map, _RET_IP_); |
5056 |
++ do_raw_spin_unlock(&src_rq->lock); |
5057 |
++ } |
5058 |
++ } while (++topo_mask < end_mask); |
5059 |
++ |
5060 |
++ return 0; |
5061 |
++} |
5062 |
++#endif |
5063 |
++ |
5064 |
++/* |
5065 |
++ * Timeslices below RESCHED_NS are considered as good as expired as there's no |
5066 |
++ * point rescheduling when there's so little time left. |
5067 |
++ */ |
5068 |
++static inline void check_curr(struct task_struct *p, struct rq *rq) |
5069 |
++{ |
5070 |
++ if (unlikely(rq->idle == p)) |
5071 |
++ return; |
5072 |
++ |
5073 |
++ update_curr(rq, p); |
5074 |
++ |
5075 |
++ if (p->time_slice < RESCHED_NS) |
5076 |
++ time_slice_expired(p, rq); |
5077 |
++} |
5078 |
++ |
5079 |
++static inline struct task_struct * |
5080 |
++choose_next_task(struct rq *rq, int cpu, struct task_struct *prev) |
5081 |
++{ |
5082 |
++ struct task_struct *next; |
5083 |
++ |
5084 |
++ if (unlikely(rq->skip)) { |
5085 |
++ next = rq_runnable_task(rq); |
5086 |
++ if (next == rq->idle) { |
5087 |
++#ifdef CONFIG_SMP |
5088 |
++ if (!take_other_rq_tasks(rq, cpu)) { |
5089 |
++#endif |
5090 |
++ rq->skip = NULL; |
5091 |
++ schedstat_inc(rq->sched_goidle); |
5092 |
++ return next; |
5093 |
++#ifdef CONFIG_SMP |
5094 |
++ } |
5095 |
++ next = rq_runnable_task(rq); |
5096 |
++#endif |
5097 |
++ } |
5098 |
++ rq->skip = NULL; |
5099 |
++#ifdef CONFIG_HIGH_RES_TIMERS |
5100 |
++ hrtick_start(rq, next->time_slice); |
5101 |
++#endif |
5102 |
++ return next; |
5103 |
++ } |
5104 |
++ |
5105 |
++ next = sched_rq_first_task(rq); |
5106 |
++ if (next == rq->idle) { |
5107 |
++#ifdef CONFIG_SMP |
5108 |
++ if (!take_other_rq_tasks(rq, cpu)) { |
5109 |
++#endif |
5110 |
++ schedstat_inc(rq->sched_goidle); |
5111 |
++ /*printk(KERN_INFO "sched: choose_next_task(%d) idle %px\n", cpu, next);*/ |
5112 |
++ return next; |
5113 |
++#ifdef CONFIG_SMP |
5114 |
++ } |
5115 |
++ next = sched_rq_first_task(rq); |
5116 |
++#endif |
5117 |
++ } |
5118 |
++#ifdef CONFIG_HIGH_RES_TIMERS |
5119 |
++ hrtick_start(rq, next->time_slice); |
5120 |
++#endif |
5121 |
++ /*printk(KERN_INFO "sched: choose_next_task(%d) next %px\n", cpu, |
5122 |
++ * next);*/ |
5123 |
++ return next; |
5124 |
++} |
5125 |
++ |
5126 |
++/* |
5127 |
++ * Constants for the sched_mode argument of __schedule(). |
5128 |
++ * |
5129 |
++ * The mode argument allows RT enabled kernels to differentiate a |
5130 |
++ * preemption from blocking on an 'sleeping' spin/rwlock. Note that |
5131 |
++ * SM_MASK_PREEMPT for !RT has all bits set, which allows the compiler to |
5132 |
++ * optimize the AND operation out and just check for zero. |
5133 |
++ */ |
5134 |
++#define SM_NONE 0x0 |
5135 |
++#define SM_PREEMPT 0x1 |
5136 |
++#define SM_RTLOCK_WAIT 0x2 |
5137 |
++ |
5138 |
++#ifndef CONFIG_PREEMPT_RT |
5139 |
++# define SM_MASK_PREEMPT (~0U) |
5140 |
++#else |
5141 |
++# define SM_MASK_PREEMPT SM_PREEMPT |
5142 |
++#endif |
5143 |
++ |
5144 |
++/* |
5145 |
++ * schedule() is the main scheduler function. |
5146 |
++ * |
5147 |
++ * The main means of driving the scheduler and thus entering this function are: |
5148 |
++ * |
5149 |
++ * 1. Explicit blocking: mutex, semaphore, waitqueue, etc. |
5150 |
++ * |
5151 |
++ * 2. TIF_NEED_RESCHED flag is checked on interrupt and userspace return |
5152 |
++ * paths. For example, see arch/x86/entry_64.S. |
5153 |
++ * |
5154 |
++ * To drive preemption between tasks, the scheduler sets the flag in timer |
5155 |
++ * interrupt handler scheduler_tick(). |
5156 |
++ * |
5157 |
++ * 3. Wakeups don't really cause entry into schedule(). They add a |
5158 |
++ * task to the run-queue and that's it. |
5159 |
++ * |
5160 |
++ * Now, if the new task added to the run-queue preempts the current |
5161 |
++ * task, then the wakeup sets TIF_NEED_RESCHED and schedule() gets |
5162 |
++ * called on the nearest possible occasion: |
5163 |
++ * |
5164 |
++ * - If the kernel is preemptible (CONFIG_PREEMPTION=y): |
5165 |
++ * |
5166 |
++ * - in syscall or exception context, at the next outmost |
5167 |
++ * preempt_enable(). (this might be as soon as the wake_up()'s |
5168 |
++ * spin_unlock()!) |
5169 |
++ * |
5170 |
++ * - in IRQ context, return from interrupt-handler to |
5171 |
++ * preemptible context |
5172 |
++ * |
5173 |
++ * - If the kernel is not preemptible (CONFIG_PREEMPTION is not set) |
5174 |
++ * then at the next: |
5175 |
++ * |
5176 |
++ * - cond_resched() call |
5177 |
++ * - explicit schedule() call |
5178 |
++ * - return from syscall or exception to user-space |
5179 |
++ * - return from interrupt-handler to user-space |
5180 |
++ * |
5181 |
++ * WARNING: must be called with preemption disabled! |
5182 |
++ */ |
5183 |
++static void __sched notrace __schedule(unsigned int sched_mode) |
5184 |
++{ |
5185 |
++ struct task_struct *prev, *next; |
5186 |
++ unsigned long *switch_count; |
5187 |
++ unsigned long prev_state; |
5188 |
++ struct rq *rq; |
5189 |
++ int cpu; |
5190 |
++ int deactivated = 0; |
5191 |
++ |
5192 |
++ cpu = smp_processor_id(); |
5193 |
++ rq = cpu_rq(cpu); |
5194 |
++ prev = rq->curr; |
5195 |
++ |
5196 |
++ schedule_debug(prev, !!sched_mode); |
5197 |
++ |
5198 |
++ /* by passing sched_feat(HRTICK) checking which Alt schedule FW doesn't support */ |
5199 |
++ hrtick_clear(rq); |
5200 |
++ |
5201 |
++ local_irq_disable(); |
5202 |
++ rcu_note_context_switch(!!sched_mode); |
5203 |
++ |
5204 |
++ /* |
5205 |
++ * Make sure that signal_pending_state()->signal_pending() below |
5206 |
++ * can't be reordered with __set_current_state(TASK_INTERRUPTIBLE) |
5207 |
++ * done by the caller to avoid the race with signal_wake_up(): |
5208 |
++ * |
5209 |
++ * __set_current_state(@state) signal_wake_up() |
5210 |
++ * schedule() set_tsk_thread_flag(p, TIF_SIGPENDING) |
5211 |
++ * wake_up_state(p, state) |
5212 |
++ * LOCK rq->lock LOCK p->pi_state |
5213 |
++ * smp_mb__after_spinlock() smp_mb__after_spinlock() |
5214 |
++ * if (signal_pending_state()) if (p->state & @state) |
5215 |
++ * |
5216 |
++ * Also, the membarrier system call requires a full memory barrier |
5217 |
++ * after coming from user-space, before storing to rq->curr. |
5218 |
++ */ |
5219 |
++ raw_spin_lock(&rq->lock); |
5220 |
++ smp_mb__after_spinlock(); |
5221 |
++ |
5222 |
++ update_rq_clock(rq); |
5223 |
++ |
5224 |
++ switch_count = &prev->nivcsw; |
5225 |
++ /* |
5226 |
++ * We must load prev->state once (task_struct::state is volatile), such |
5227 |
++ * that we form a control dependency vs deactivate_task() below. |
5228 |
++ */ |
5229 |
++ prev_state = READ_ONCE(prev->__state); |
5230 |
++ if (!(sched_mode & SM_MASK_PREEMPT) && prev_state) { |
5231 |
++ if (signal_pending_state(prev_state, prev)) { |
5232 |
++ WRITE_ONCE(prev->__state, TASK_RUNNING); |
5233 |
++ } else { |
5234 |
++ prev->sched_contributes_to_load = |
5235 |
++ (prev_state & TASK_UNINTERRUPTIBLE) && |
5236 |
++ !(prev_state & TASK_NOLOAD) && |
5237 |
++ !(prev->flags & PF_FROZEN); |
5238 |
++ |
5239 |
++ if (prev->sched_contributes_to_load) |
5240 |
++ rq->nr_uninterruptible++; |
5241 |
++ |
5242 |
++ /* |
5243 |
++ * __schedule() ttwu() |
5244 |
++ * prev_state = prev->state; if (p->on_rq && ...) |
5245 |
++ * if (prev_state) goto out; |
5246 |
++ * p->on_rq = 0; smp_acquire__after_ctrl_dep(); |
5247 |
++ * p->state = TASK_WAKING |
5248 |
++ * |
5249 |
++ * Where __schedule() and ttwu() have matching control dependencies. |
5250 |
++ * |
5251 |
++ * After this, schedule() must not care about p->state any more. |
5252 |
++ */ |
5253 |
++ sched_task_deactivate(prev, rq); |
5254 |
++ deactivate_task(prev, rq); |
5255 |
++ deactivated = 1; |
5256 |
++ |
5257 |
++ if (prev->in_iowait) { |
5258 |
++ atomic_inc(&rq->nr_iowait); |
5259 |
++ delayacct_blkio_start(); |
5260 |
++ } |
5261 |
++ } |
5262 |
++ switch_count = &prev->nvcsw; |
5263 |
++ } |
5264 |
++ |
5265 |
++ check_curr(prev, rq); |
5266 |
++ |
5267 |
++ next = choose_next_task(rq, cpu, prev); |
5268 |
++ clear_tsk_need_resched(prev); |
5269 |
++ clear_preempt_need_resched(); |
5270 |
++#ifdef CONFIG_SCHED_DEBUG |
5271 |
++ rq->last_seen_need_resched_ns = 0; |
5272 |
++#endif |
5273 |
++ |
5274 |
++ if (likely(prev != next)) { |
5275 |
++ if (deactivated) |
5276 |
++ update_sched_rq_watermark(rq); |
5277 |
++ next->last_ran = rq->clock_task; |
5278 |
++ rq->last_ts_switch = rq->clock; |
5279 |
++ |
5280 |
++ rq->nr_switches++; |
5281 |
++ /* |
5282 |
++ * RCU users of rcu_dereference(rq->curr) may not see |
5283 |
++ * changes to task_struct made by pick_next_task(). |
5284 |
++ */ |
5285 |
++ RCU_INIT_POINTER(rq->curr, next); |
5286 |
++ /* |
5287 |
++ * The membarrier system call requires each architecture |
5288 |
++ * to have a full memory barrier after updating |
5289 |
++ * rq->curr, before returning to user-space. |
5290 |
++ * |
5291 |
++ * Here are the schemes providing that barrier on the |
5292 |
++ * various architectures: |
5293 |
++ * - mm ? switch_mm() : mmdrop() for x86, s390, sparc, PowerPC. |
5294 |
++ * switch_mm() rely on membarrier_arch_switch_mm() on PowerPC. |
5295 |
++ * - finish_lock_switch() for weakly-ordered |
5296 |
++ * architectures where spin_unlock is a full barrier, |
5297 |
++ * - switch_to() for arm64 (weakly-ordered, spin_unlock |
5298 |
++ * is a RELEASE barrier), |
5299 |
++ */ |
5300 |
++ ++*switch_count; |
5301 |
++ |
5302 |
++ psi_sched_switch(prev, next, !task_on_rq_queued(prev)); |
5303 |
++ |
5304 |
++ trace_sched_switch(sched_mode & SM_MASK_PREEMPT, prev, next, prev_state); |
5305 |
++ |
5306 |
++ /* Also unlocks the rq: */ |
5307 |
++ rq = context_switch(rq, prev, next); |
5308 |
++ } else { |
5309 |
++ __balance_callbacks(rq); |
5310 |
++ raw_spin_unlock_irq(&rq->lock); |
5311 |
++ } |
5312 |
++ |
5313 |
++#ifdef CONFIG_SCHED_SMT |
5314 |
++ sg_balance(rq); |
5315 |
++#endif |
5316 |
++} |
5317 |
++ |
5318 |
++void __noreturn do_task_dead(void) |
5319 |
++{ |
5320 |
++ /* Causes final put_task_struct in finish_task_switch(): */ |
5321 |
++ set_special_state(TASK_DEAD); |
5322 |
++ |
5323 |
++ /* Tell freezer to ignore us: */ |
5324 |
++ current->flags |= PF_NOFREEZE; |
5325 |
++ |
5326 |
++ __schedule(SM_NONE); |
5327 |
++ BUG(); |
5328 |
++ |
5329 |
++ /* Avoid "noreturn function does return" - but don't continue if BUG() is a NOP: */ |
5330 |
++ for (;;) |
5331 |
++ cpu_relax(); |
5332 |
++} |
5333 |
++ |
5334 |
++static inline void sched_submit_work(struct task_struct *tsk) |
5335 |
++{ |
5336 |
++ unsigned int task_flags; |
5337 |
++ |
5338 |
++ if (task_is_running(tsk)) |
5339 |
++ return; |
5340 |
++ |
5341 |
++ task_flags = tsk->flags; |
5342 |
++ /* |
5343 |
++ * If a worker goes to sleep, notify and ask workqueue whether it |
5344 |
++ * wants to wake up a task to maintain concurrency. |
5345 |
++ */ |
5346 |
++ if (task_flags & (PF_WQ_WORKER | PF_IO_WORKER)) { |
5347 |
++ if (task_flags & PF_WQ_WORKER) |
5348 |
++ wq_worker_sleeping(tsk); |
5349 |
++ else |
5350 |
++ io_wq_worker_sleeping(tsk); |
5351 |
++ } |
5352 |
++ |
5353 |
++ if (tsk_is_pi_blocked(tsk)) |
5354 |
++ return; |
5355 |
++ |
5356 |
++ /* |
5357 |
++ * If we are going to sleep and we have plugged IO queued, |
5358 |
++ * make sure to submit it to avoid deadlocks. |
5359 |
++ */ |
5360 |
++ blk_flush_plug(tsk->plug, true); |
5361 |
++} |
5362 |
++ |
5363 |
++static void sched_update_worker(struct task_struct *tsk) |
5364 |
++{ |
5365 |
++ if (tsk->flags & (PF_WQ_WORKER | PF_IO_WORKER)) { |
5366 |
++ if (tsk->flags & PF_WQ_WORKER) |
5367 |
++ wq_worker_running(tsk); |
5368 |
++ else |
5369 |
++ io_wq_worker_running(tsk); |
5370 |
++ } |
5371 |
++} |
5372 |
++ |
5373 |
++asmlinkage __visible void __sched schedule(void) |
5374 |
++{ |
5375 |
++ struct task_struct *tsk = current; |
5376 |
++ |
5377 |
++ sched_submit_work(tsk); |
5378 |
++ do { |
5379 |
++ preempt_disable(); |
5380 |
++ __schedule(SM_NONE); |
5381 |
++ sched_preempt_enable_no_resched(); |
5382 |
++ } while (need_resched()); |
5383 |
++ sched_update_worker(tsk); |
5384 |
++} |
5385 |
++EXPORT_SYMBOL(schedule); |
5386 |
++ |
5387 |
++/* |
5388 |
++ * synchronize_rcu_tasks() makes sure that no task is stuck in preempted |
5389 |
++ * state (have scheduled out non-voluntarily) by making sure that all |
5390 |
++ * tasks have either left the run queue or have gone into user space. |
5391 |
++ * As idle tasks do not do either, they must not ever be preempted |
5392 |
++ * (schedule out non-voluntarily). |
5393 |
++ * |
5394 |
++ * schedule_idle() is similar to schedule_preempt_disable() except that it |
5395 |
++ * never enables preemption because it does not call sched_submit_work(). |
5396 |
++ */ |
5397 |
++void __sched schedule_idle(void) |
5398 |
++{ |
5399 |
++ /* |
5400 |
++ * As this skips calling sched_submit_work(), which the idle task does |
5401 |
++ * regardless because that function is a nop when the task is in a |
5402 |
++ * TASK_RUNNING state, make sure this isn't used someplace that the |
5403 |
++ * current task can be in any other state. Note, idle is always in the |
5404 |
++ * TASK_RUNNING state. |
5405 |
++ */ |
5406 |
++ WARN_ON_ONCE(current->__state); |
5407 |
++ do { |
5408 |
++ __schedule(SM_NONE); |
5409 |
++ } while (need_resched()); |
5410 |
++} |
5411 |
++ |
5412 |
++#if defined(CONFIG_CONTEXT_TRACKING) && !defined(CONFIG_HAVE_CONTEXT_TRACKING_OFFSTACK) |
5413 |
++asmlinkage __visible void __sched schedule_user(void) |
5414 |
++{ |
5415 |
++ /* |
5416 |
++ * If we come here after a random call to set_need_resched(), |
5417 |
++ * or we have been woken up remotely but the IPI has not yet arrived, |
5418 |
++ * we haven't yet exited the RCU idle mode. Do it here manually until |
5419 |
++ * we find a better solution. |
5420 |
++ * |
5421 |
++ * NB: There are buggy callers of this function. Ideally we |
5422 |
++ * should warn if prev_state != CONTEXT_USER, but that will trigger |
5423 |
++ * too frequently to make sense yet. |
5424 |
++ */ |
5425 |
++ enum ctx_state prev_state = exception_enter(); |
5426 |
++ schedule(); |
5427 |
++ exception_exit(prev_state); |
5428 |
++} |
5429 |
++#endif |
5430 |
++ |
5431 |
++/** |
5432 |
++ * schedule_preempt_disabled - called with preemption disabled |
5433 |
++ * |
5434 |
++ * Returns with preemption disabled. Note: preempt_count must be 1 |
5435 |
++ */ |
5436 |
++void __sched schedule_preempt_disabled(void) |
5437 |
++{ |
5438 |
++ sched_preempt_enable_no_resched(); |
5439 |
++ schedule(); |
5440 |
++ preempt_disable(); |
5441 |
++} |
5442 |
++ |
5443 |
++#ifdef CONFIG_PREEMPT_RT |
5444 |
++void __sched notrace schedule_rtlock(void) |
5445 |
++{ |
5446 |
++ do { |
5447 |
++ preempt_disable(); |
5448 |
++ __schedule(SM_RTLOCK_WAIT); |
5449 |
++ sched_preempt_enable_no_resched(); |
5450 |
++ } while (need_resched()); |
5451 |
++} |
5452 |
++NOKPROBE_SYMBOL(schedule_rtlock); |
5453 |
++#endif |
5454 |
++ |
5455 |
++static void __sched notrace preempt_schedule_common(void) |
5456 |
++{ |
5457 |
++ do { |
5458 |
++ /* |
5459 |
++ * Because the function tracer can trace preempt_count_sub() |
5460 |
++ * and it also uses preempt_enable/disable_notrace(), if |
5461 |
++ * NEED_RESCHED is set, the preempt_enable_notrace() called |
5462 |
++ * by the function tracer will call this function again and |
5463 |
++ * cause infinite recursion. |
5464 |
++ * |
5465 |
++ * Preemption must be disabled here before the function |
5466 |
++ * tracer can trace. Break up preempt_disable() into two |
5467 |
++ * calls. One to disable preemption without fear of being |
5468 |
++ * traced. The other to still record the preemption latency, |
5469 |
++ * which can also be traced by the function tracer. |
5470 |
++ */ |
5471 |
++ preempt_disable_notrace(); |
5472 |
++ preempt_latency_start(1); |
5473 |
++ __schedule(SM_PREEMPT); |
5474 |
++ preempt_latency_stop(1); |
5475 |
++ preempt_enable_no_resched_notrace(); |
5476 |
++ |
5477 |
++ /* |
5478 |
++ * Check again in case we missed a preemption opportunity |
5479 |
++ * between schedule and now. |
5480 |
++ */ |
5481 |
++ } while (need_resched()); |
5482 |
++} |
5483 |
++ |
5484 |
++#ifdef CONFIG_PREEMPTION |
5485 |
++/* |
5486 |
++ * This is the entry point to schedule() from in-kernel preemption |
5487 |
++ * off of preempt_enable. |
5488 |
++ */ |
5489 |
++asmlinkage __visible void __sched notrace preempt_schedule(void) |
5490 |
++{ |
5491 |
++ /* |
5492 |
++ * If there is a non-zero preempt_count or interrupts are disabled, |
5493 |
++ * we do not want to preempt the current task. Just return.. |
5494 |
++ */ |
5495 |
++ if (likely(!preemptible())) |
5496 |
++ return; |
5497 |
++ |
5498 |
++ preempt_schedule_common(); |
5499 |
++} |
5500 |
++NOKPROBE_SYMBOL(preempt_schedule); |
5501 |
++EXPORT_SYMBOL(preempt_schedule); |
5502 |
++ |
5503 |
++#ifdef CONFIG_PREEMPT_DYNAMIC |
5504 |
++#if defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) |
5505 |
++#ifndef preempt_schedule_dynamic_enabled |
5506 |
++#define preempt_schedule_dynamic_enabled preempt_schedule |
5507 |
++#define preempt_schedule_dynamic_disabled NULL |
5508 |
++#endif |
5509 |
++DEFINE_STATIC_CALL(preempt_schedule, preempt_schedule_dynamic_enabled); |
5510 |
++EXPORT_STATIC_CALL_TRAMP(preempt_schedule); |
5511 |
++#elif defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) |
5512 |
++static DEFINE_STATIC_KEY_TRUE(sk_dynamic_preempt_schedule); |
5513 |
++void __sched notrace dynamic_preempt_schedule(void) |
5514 |
++{ |
5515 |
++ if (!static_branch_unlikely(&sk_dynamic_preempt_schedule)) |
5516 |
++ return; |
5517 |
++ preempt_schedule(); |
5518 |
++} |
5519 |
++NOKPROBE_SYMBOL(dynamic_preempt_schedule); |
5520 |
++EXPORT_SYMBOL(dynamic_preempt_schedule); |
5521 |
++#endif |
5522 |
++#endif |
5523 |
++ |
5524 |
++/** |
5525 |
++ * preempt_schedule_notrace - preempt_schedule called by tracing |
5526 |
++ * |
5527 |
++ * The tracing infrastructure uses preempt_enable_notrace to prevent |
5528 |
++ * recursion and tracing preempt enabling caused by the tracing |
5529 |
++ * infrastructure itself. But as tracing can happen in areas coming |
5530 |
++ * from userspace or just about to enter userspace, a preempt enable |
5531 |
++ * can occur before user_exit() is called. This will cause the scheduler |
5532 |
++ * to be called when the system is still in usermode. |
5533 |
++ * |
5534 |
++ * To prevent this, the preempt_enable_notrace will use this function |
5535 |
++ * instead of preempt_schedule() to exit user context if needed before |
5536 |
++ * calling the scheduler. |
5537 |
++ */ |
5538 |
++asmlinkage __visible void __sched notrace preempt_schedule_notrace(void) |
5539 |
++{ |
5540 |
++ enum ctx_state prev_ctx; |
5541 |
++ |
5542 |
++ if (likely(!preemptible())) |
5543 |
++ return; |
5544 |
++ |
5545 |
++ do { |
5546 |
++ /* |
5547 |
++ * Because the function tracer can trace preempt_count_sub() |
5548 |
++ * and it also uses preempt_enable/disable_notrace(), if |
5549 |
++ * NEED_RESCHED is set, the preempt_enable_notrace() called |
5550 |
++ * by the function tracer will call this function again and |
5551 |
++ * cause infinite recursion. |
5552 |
++ * |
5553 |
++ * Preemption must be disabled here before the function |
5554 |
++ * tracer can trace. Break up preempt_disable() into two |
5555 |
++ * calls. One to disable preemption without fear of being |
5556 |
++ * traced. The other to still record the preemption latency, |
5557 |
++ * which can also be traced by the function tracer. |
5558 |
++ */ |
5559 |
++ preempt_disable_notrace(); |
5560 |
++ preempt_latency_start(1); |
5561 |
++ /* |
5562 |
++ * Needs preempt disabled in case user_exit() is traced |
5563 |
++ * and the tracer calls preempt_enable_notrace() causing |
5564 |
++ * an infinite recursion. |
5565 |
++ */ |
5566 |
++ prev_ctx = exception_enter(); |
5567 |
++ __schedule(SM_PREEMPT); |
5568 |
++ exception_exit(prev_ctx); |
5569 |
++ |
5570 |
++ preempt_latency_stop(1); |
5571 |
++ preempt_enable_no_resched_notrace(); |
5572 |
++ } while (need_resched()); |
5573 |
++} |
5574 |
++EXPORT_SYMBOL_GPL(preempt_schedule_notrace); |
5575 |
++ |
5576 |
++#ifdef CONFIG_PREEMPT_DYNAMIC |
5577 |
++#if defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) |
5578 |
++#ifndef preempt_schedule_notrace_dynamic_enabled |
5579 |
++#define preempt_schedule_notrace_dynamic_enabled preempt_schedule_notrace |
5580 |
++#define preempt_schedule_notrace_dynamic_disabled NULL |
5581 |
++#endif |
5582 |
++DEFINE_STATIC_CALL(preempt_schedule_notrace, preempt_schedule_notrace_dynamic_enabled); |
5583 |
++EXPORT_STATIC_CALL_TRAMP(preempt_schedule_notrace); |
5584 |
++#elif defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) |
5585 |
++static DEFINE_STATIC_KEY_TRUE(sk_dynamic_preempt_schedule_notrace); |
5586 |
++void __sched notrace dynamic_preempt_schedule_notrace(void) |
5587 |
++{ |
5588 |
++ if (!static_branch_unlikely(&sk_dynamic_preempt_schedule_notrace)) |
5589 |
++ return; |
5590 |
++ preempt_schedule_notrace(); |
5591 |
++} |
5592 |
++NOKPROBE_SYMBOL(dynamic_preempt_schedule_notrace); |
5593 |
++EXPORT_SYMBOL(dynamic_preempt_schedule_notrace); |
5594 |
++#endif |
5595 |
++#endif |
5596 |
++ |
5597 |
++#endif /* CONFIG_PREEMPTION */ |
5598 |
++ |
5599 |
++/* |
5600 |
++ * This is the entry point to schedule() from kernel preemption |
5601 |
++ * off of irq context. |
5602 |
++ * Note, that this is called and return with irqs disabled. This will |
5603 |
++ * protect us against recursive calling from irq. |
5604 |
++ */ |
5605 |
++asmlinkage __visible void __sched preempt_schedule_irq(void) |
5606 |
++{ |
5607 |
++ enum ctx_state prev_state; |
5608 |
++ |
5609 |
++ /* Catch callers which need to be fixed */ |
5610 |
++ BUG_ON(preempt_count() || !irqs_disabled()); |
5611 |
++ |
5612 |
++ prev_state = exception_enter(); |
5613 |
++ |
5614 |
++ do { |
5615 |
++ preempt_disable(); |
5616 |
++ local_irq_enable(); |
5617 |
++ __schedule(SM_PREEMPT); |
5618 |
++ local_irq_disable(); |
5619 |
++ sched_preempt_enable_no_resched(); |
5620 |
++ } while (need_resched()); |
5621 |
++ |
5622 |
++ exception_exit(prev_state); |
5623 |
++} |
5624 |
++ |
5625 |
++int default_wake_function(wait_queue_entry_t *curr, unsigned mode, int wake_flags, |
5626 |
++ void *key) |
5627 |
++{ |
5628 |
++ WARN_ON_ONCE(IS_ENABLED(CONFIG_SCHED_DEBUG) && wake_flags & ~WF_SYNC); |
5629 |
++ return try_to_wake_up(curr->private, mode, wake_flags); |
5630 |
++} |
5631 |
++EXPORT_SYMBOL(default_wake_function); |
5632 |
++ |
5633 |
++static inline void check_task_changed(struct task_struct *p, struct rq *rq) |
5634 |
++{ |
5635 |
++ int idx; |
5636 |
++ |
5637 |
++ /* Trigger resched if task sched_prio has been modified. */ |
5638 |
++ if (task_on_rq_queued(p) && (idx = task_sched_prio_idx(p, rq)) != p->sq_idx) { |
5639 |
++ requeue_task(p, rq, idx); |
5640 |
++ check_preempt_curr(rq); |
5641 |
++ } |
5642 |
++} |
5643 |
++ |
5644 |
++static void __setscheduler_prio(struct task_struct *p, int prio) |
5645 |
++{ |
5646 |
++ p->prio = prio; |
5647 |
++} |
5648 |
++ |
5649 |
++#ifdef CONFIG_RT_MUTEXES |
5650 |
++ |
5651 |
++static inline int __rt_effective_prio(struct task_struct *pi_task, int prio) |
5652 |
++{ |
5653 |
++ if (pi_task) |
5654 |
++ prio = min(prio, pi_task->prio); |
5655 |
++ |
5656 |
++ return prio; |
5657 |
++} |
5658 |
++ |
5659 |
++static inline int rt_effective_prio(struct task_struct *p, int prio) |
5660 |
++{ |
5661 |
++ struct task_struct *pi_task = rt_mutex_get_top_task(p); |
5662 |
++ |
5663 |
++ return __rt_effective_prio(pi_task, prio); |
5664 |
++} |
5665 |
++ |
5666 |
++/* |
5667 |
++ * rt_mutex_setprio - set the current priority of a task |
5668 |
++ * @p: task to boost |
5669 |
++ * @pi_task: donor task |
5670 |
++ * |
5671 |
++ * This function changes the 'effective' priority of a task. It does |
5672 |
++ * not touch ->normal_prio like __setscheduler(). |
5673 |
++ * |
5674 |
++ * Used by the rt_mutex code to implement priority inheritance |
5675 |
++ * logic. Call site only calls if the priority of the task changed. |
5676 |
++ */ |
5677 |
++void rt_mutex_setprio(struct task_struct *p, struct task_struct *pi_task) |
5678 |
++{ |
5679 |
++ int prio; |
5680 |
++ struct rq *rq; |
5681 |
++ raw_spinlock_t *lock; |
5682 |
++ |
5683 |
++ /* XXX used to be waiter->prio, not waiter->task->prio */ |
5684 |
++ prio = __rt_effective_prio(pi_task, p->normal_prio); |
5685 |
++ |
5686 |
++ /* |
5687 |
++ * If nothing changed; bail early. |
5688 |
++ */ |
5689 |
++ if (p->pi_top_task == pi_task && prio == p->prio) |
5690 |
++ return; |
5691 |
++ |
5692 |
++ rq = __task_access_lock(p, &lock); |
5693 |
++ /* |
5694 |
++ * Set under pi_lock && rq->lock, such that the value can be used under |
5695 |
++ * either lock. |
5696 |
++ * |
5697 |
++ * Note that there is loads of tricky to make this pointer cache work |
5698 |
++ * right. rt_mutex_slowunlock()+rt_mutex_postunlock() work together to |
5699 |
++ * ensure a task is de-boosted (pi_task is set to NULL) before the |
5700 |
++ * task is allowed to run again (and can exit). This ensures the pointer |
5701 |
++ * points to a blocked task -- which guarantees the task is present. |
5702 |
++ */ |
5703 |
++ p->pi_top_task = pi_task; |
5704 |
++ |
5705 |
++ /* |
5706 |
++ * For FIFO/RR we only need to set prio, if that matches we're done. |
5707 |
++ */ |
5708 |
++ if (prio == p->prio) |
5709 |
++ goto out_unlock; |
5710 |
++ |
5711 |
++ /* |
5712 |
++ * Idle task boosting is a nono in general. There is one |
5713 |
++ * exception, when PREEMPT_RT and NOHZ is active: |
5714 |
++ * |
5715 |
++ * The idle task calls get_next_timer_interrupt() and holds |
5716 |
++ * the timer wheel base->lock on the CPU and another CPU wants |
5717 |
++ * to access the timer (probably to cancel it). We can safely |
5718 |
++ * ignore the boosting request, as the idle CPU runs this code |
5719 |
++ * with interrupts disabled and will complete the lock |
5720 |
++ * protected section without being interrupted. So there is no |
5721 |
++ * real need to boost. |
5722 |
++ */ |
5723 |
++ if (unlikely(p == rq->idle)) { |
5724 |
++ WARN_ON(p != rq->curr); |
5725 |
++ WARN_ON(p->pi_blocked_on); |
5726 |
++ goto out_unlock; |
5727 |
++ } |
5728 |
++ |
5729 |
++ trace_sched_pi_setprio(p, pi_task); |
5730 |
++ |
5731 |
++ __setscheduler_prio(p, prio); |
5732 |
++ |
5733 |
++ check_task_changed(p, rq); |
5734 |
++out_unlock: |
5735 |
++ /* Avoid rq from going away on us: */ |
5736 |
++ preempt_disable(); |
5737 |
++ |
5738 |
++ __balance_callbacks(rq); |
5739 |
++ __task_access_unlock(p, lock); |
5740 |
++ |
5741 |
++ preempt_enable(); |
5742 |
++} |
5743 |
++#else |
5744 |
++static inline int rt_effective_prio(struct task_struct *p, int prio) |
5745 |
++{ |
5746 |
++ return prio; |
5747 |
++} |
5748 |
++#endif |
5749 |
++ |
5750 |
++void set_user_nice(struct task_struct *p, long nice) |
5751 |
++{ |
5752 |
++ unsigned long flags; |
5753 |
++ struct rq *rq; |
5754 |
++ raw_spinlock_t *lock; |
5755 |
++ |
5756 |
++ if (task_nice(p) == nice || nice < MIN_NICE || nice > MAX_NICE) |
5757 |
++ return; |
5758 |
++ /* |
5759 |
++ * We have to be careful, if called from sys_setpriority(), |
5760 |
++ * the task might be in the middle of scheduling on another CPU. |
5761 |
++ */ |
5762 |
++ raw_spin_lock_irqsave(&p->pi_lock, flags); |
5763 |
++ rq = __task_access_lock(p, &lock); |
5764 |
++ |
5765 |
++ p->static_prio = NICE_TO_PRIO(nice); |
5766 |
++ /* |
5767 |
++ * The RT priorities are set via sched_setscheduler(), but we still |
5768 |
++ * allow the 'normal' nice value to be set - but as expected |
5769 |
++ * it won't have any effect on scheduling until the task is |
5770 |
++ * not SCHED_NORMAL/SCHED_BATCH: |
5771 |
++ */ |
5772 |
++ if (task_has_rt_policy(p)) |
5773 |
++ goto out_unlock; |
5774 |
++ |
5775 |
++ p->prio = effective_prio(p); |
5776 |
++ |
5777 |
++ check_task_changed(p, rq); |
5778 |
++out_unlock: |
5779 |
++ __task_access_unlock(p, lock); |
5780 |
++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
5781 |
++} |
5782 |
++EXPORT_SYMBOL(set_user_nice); |
5783 |
++ |
5784 |
++/* |
5785 |
++ * can_nice - check if a task can reduce its nice value |
5786 |
++ * @p: task |
5787 |
++ * @nice: nice value |
5788 |
++ */ |
5789 |
++int can_nice(const struct task_struct *p, const int nice) |
5790 |
++{ |
5791 |
++ /* Convert nice value [19,-20] to rlimit style value [1,40] */ |
5792 |
++ int nice_rlim = nice_to_rlimit(nice); |
5793 |
++ |
5794 |
++ return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) || |
5795 |
++ capable(CAP_SYS_NICE)); |
5796 |
++} |
5797 |
++ |
5798 |
++#ifdef __ARCH_WANT_SYS_NICE |
5799 |
++ |
5800 |
++/* |
5801 |
++ * sys_nice - change the priority of the current process. |
5802 |
++ * @increment: priority increment |
5803 |
++ * |
5804 |
++ * sys_setpriority is a more generic, but much slower function that |
5805 |
++ * does similar things. |
5806 |
++ */ |
5807 |
++SYSCALL_DEFINE1(nice, int, increment) |
5808 |
++{ |
5809 |
++ long nice, retval; |
5810 |
++ |
5811 |
++ /* |
5812 |
++ * Setpriority might change our priority at the same moment. |
5813 |
++ * We don't have to worry. Conceptually one call occurs first |
5814 |
++ * and we have a single winner. |
5815 |
++ */ |
5816 |
++ |
5817 |
++ increment = clamp(increment, -NICE_WIDTH, NICE_WIDTH); |
5818 |
++ nice = task_nice(current) + increment; |
5819 |
++ |
5820 |
++ nice = clamp_val(nice, MIN_NICE, MAX_NICE); |
5821 |
++ if (increment < 0 && !can_nice(current, nice)) |
5822 |
++ return -EPERM; |
5823 |
++ |
5824 |
++ retval = security_task_setnice(current, nice); |
5825 |
++ if (retval) |
5826 |
++ return retval; |
5827 |
++ |
5828 |
++ set_user_nice(current, nice); |
5829 |
++ return 0; |
5830 |
++} |
5831 |
++ |
5832 |
++#endif |
5833 |
++ |
5834 |
++/** |
5835 |
++ * task_prio - return the priority value of a given task. |
5836 |
++ * @p: the task in question. |
5837 |
++ * |
5838 |
++ * Return: The priority value as seen by users in /proc. |
5839 |
++ * |
5840 |
++ * sched policy return value kernel prio user prio/nice |
5841 |
++ * |
5842 |
++ * (BMQ)normal, batch, idle[0 ... 53] [100 ... 139] 0/[-20 ... 19]/[-7 ... 7] |
5843 |
++ * (PDS)normal, batch, idle[0 ... 39] 100 0/[-20 ... 19] |
5844 |
++ * fifo, rr [-1 ... -100] [99 ... 0] [0 ... 99] |
5845 |
++ */ |
5846 |
++int task_prio(const struct task_struct *p) |
5847 |
++{ |
5848 |
++ return (p->prio < MAX_RT_PRIO) ? p->prio - MAX_RT_PRIO : |
5849 |
++ task_sched_prio_normal(p, task_rq(p)); |
5850 |
++} |
5851 |
++ |
5852 |
++/** |
5853 |
++ * idle_cpu - is a given CPU idle currently? |
5854 |
++ * @cpu: the processor in question. |
5855 |
++ * |
5856 |
++ * Return: 1 if the CPU is currently idle. 0 otherwise. |
5857 |
++ */ |
5858 |
++int idle_cpu(int cpu) |
5859 |
++{ |
5860 |
++ struct rq *rq = cpu_rq(cpu); |
5861 |
++ |
5862 |
++ if (rq->curr != rq->idle) |
5863 |
++ return 0; |
5864 |
++ |
5865 |
++ if (rq->nr_running) |
5866 |
++ return 0; |
5867 |
++ |
5868 |
++#ifdef CONFIG_SMP |
5869 |
++ if (rq->ttwu_pending) |
5870 |
++ return 0; |
5871 |
++#endif |
5872 |
++ |
5873 |
++ return 1; |
5874 |
++} |
5875 |
++ |
5876 |
++/** |
5877 |
++ * idle_task - return the idle task for a given CPU. |
5878 |
++ * @cpu: the processor in question. |
5879 |
++ * |
5880 |
++ * Return: The idle task for the cpu @cpu. |
5881 |
++ */ |
5882 |
++struct task_struct *idle_task(int cpu) |
5883 |
++{ |
5884 |
++ return cpu_rq(cpu)->idle; |
5885 |
++} |
5886 |
++ |
5887 |
++/** |
5888 |
++ * find_process_by_pid - find a process with a matching PID value. |
5889 |
++ * @pid: the pid in question. |
5890 |
++ * |
5891 |
++ * The task of @pid, if found. %NULL otherwise. |
5892 |
++ */ |
5893 |
++static inline struct task_struct *find_process_by_pid(pid_t pid) |
5894 |
++{ |
5895 |
++ return pid ? find_task_by_vpid(pid) : current; |
5896 |
++} |
5897 |
++ |
5898 |
++/* |
5899 |
++ * sched_setparam() passes in -1 for its policy, to let the functions |
5900 |
++ * it calls know not to change it. |
5901 |
++ */ |
5902 |
++#define SETPARAM_POLICY -1 |
5903 |
++ |
5904 |
++static void __setscheduler_params(struct task_struct *p, |
5905 |
++ const struct sched_attr *attr) |
5906 |
++{ |
5907 |
++ int policy = attr->sched_policy; |
5908 |
++ |
5909 |
++ if (policy == SETPARAM_POLICY) |
5910 |
++ policy = p->policy; |
5911 |
++ |
5912 |
++ p->policy = policy; |
5913 |
++ |
5914 |
++ /* |
5915 |
++ * allow normal nice value to be set, but will not have any |
5916 |
++ * effect on scheduling until the task not SCHED_NORMAL/ |
5917 |
++ * SCHED_BATCH |
5918 |
++ */ |
5919 |
++ p->static_prio = NICE_TO_PRIO(attr->sched_nice); |
5920 |
++ |
5921 |
++ /* |
5922 |
++ * __sched_setscheduler() ensures attr->sched_priority == 0 when |
5923 |
++ * !rt_policy. Always setting this ensures that things like |
5924 |
++ * getparam()/getattr() don't report silly values for !rt tasks. |
5925 |
++ */ |
5926 |
++ p->rt_priority = attr->sched_priority; |
5927 |
++ p->normal_prio = normal_prio(p); |
5928 |
++} |
5929 |
++ |
5930 |
++/* |
5931 |
++ * check the target process has a UID that matches the current process's |
5932 |
++ */ |
5933 |
++static bool check_same_owner(struct task_struct *p) |
5934 |
++{ |
5935 |
++ const struct cred *cred = current_cred(), *pcred; |
5936 |
++ bool match; |
5937 |
++ |
5938 |
++ rcu_read_lock(); |
5939 |
++ pcred = __task_cred(p); |
5940 |
++ match = (uid_eq(cred->euid, pcred->euid) || |
5941 |
++ uid_eq(cred->euid, pcred->uid)); |
5942 |
++ rcu_read_unlock(); |
5943 |
++ return match; |
5944 |
++} |
5945 |
++ |
5946 |
++static int __sched_setscheduler(struct task_struct *p, |
5947 |
++ const struct sched_attr *attr, |
5948 |
++ bool user, bool pi) |
5949 |
++{ |
5950 |
++ const struct sched_attr dl_squash_attr = { |
5951 |
++ .size = sizeof(struct sched_attr), |
5952 |
++ .sched_policy = SCHED_FIFO, |
5953 |
++ .sched_nice = 0, |
5954 |
++ .sched_priority = 99, |
5955 |
++ }; |
5956 |
++ int oldpolicy = -1, policy = attr->sched_policy; |
5957 |
++ int retval, newprio; |
5958 |
++ struct callback_head *head; |
5959 |
++ unsigned long flags; |
5960 |
++ struct rq *rq; |
5961 |
++ int reset_on_fork; |
5962 |
++ raw_spinlock_t *lock; |
5963 |
++ |
5964 |
++ /* The pi code expects interrupts enabled */ |
5965 |
++ BUG_ON(pi && in_interrupt()); |
5966 |
++ |
5967 |
++ /* |
5968 |
++ * Alt schedule FW supports SCHED_DEADLINE by squash it as prio 0 SCHED_FIFO |
5969 |
++ */ |
5970 |
++ if (unlikely(SCHED_DEADLINE == policy)) { |
5971 |
++ attr = &dl_squash_attr; |
5972 |
++ policy = attr->sched_policy; |
5973 |
++ } |
5974 |
++recheck: |
5975 |
++ /* Double check policy once rq lock held */ |
5976 |
++ if (policy < 0) { |
5977 |
++ reset_on_fork = p->sched_reset_on_fork; |
5978 |
++ policy = oldpolicy = p->policy; |
5979 |
++ } else { |
5980 |
++ reset_on_fork = !!(attr->sched_flags & SCHED_RESET_ON_FORK); |
5981 |
++ |
5982 |
++ if (policy > SCHED_IDLE) |
5983 |
++ return -EINVAL; |
5984 |
++ } |
5985 |
++ |
5986 |
++ if (attr->sched_flags & ~(SCHED_FLAG_ALL)) |
5987 |
++ return -EINVAL; |
5988 |
++ |
5989 |
++ /* |
5990 |
++ * Valid priorities for SCHED_FIFO and SCHED_RR are |
5991 |
++ * 1..MAX_RT_PRIO-1, valid priority for SCHED_NORMAL and |
5992 |
++ * SCHED_BATCH and SCHED_IDLE is 0. |
5993 |
++ */ |
5994 |
++ if (attr->sched_priority < 0 || |
5995 |
++ (p->mm && attr->sched_priority > MAX_RT_PRIO - 1) || |
5996 |
++ (!p->mm && attr->sched_priority > MAX_RT_PRIO - 1)) |
5997 |
++ return -EINVAL; |
5998 |
++ if ((SCHED_RR == policy || SCHED_FIFO == policy) != |
5999 |
++ (attr->sched_priority != 0)) |
6000 |
++ return -EINVAL; |
6001 |
++ |
6002 |
++ /* |
6003 |
++ * Allow unprivileged RT tasks to decrease priority: |
6004 |
++ */ |
6005 |
++ if (user && !capable(CAP_SYS_NICE)) { |
6006 |
++ if (SCHED_FIFO == policy || SCHED_RR == policy) { |
6007 |
++ unsigned long rlim_rtprio = |
6008 |
++ task_rlimit(p, RLIMIT_RTPRIO); |
6009 |
++ |
6010 |
++ /* Can't set/change the rt policy */ |
6011 |
++ if (policy != p->policy && !rlim_rtprio) |
6012 |
++ return -EPERM; |
6013 |
++ |
6014 |
++ /* Can't increase priority */ |
6015 |
++ if (attr->sched_priority > p->rt_priority && |
6016 |
++ attr->sched_priority > rlim_rtprio) |
6017 |
++ return -EPERM; |
6018 |
++ } |
6019 |
++ |
6020 |
++ /* Can't change other user's priorities */ |
6021 |
++ if (!check_same_owner(p)) |
6022 |
++ return -EPERM; |
6023 |
++ |
6024 |
++ /* Normal users shall not reset the sched_reset_on_fork flag */ |
6025 |
++ if (p->sched_reset_on_fork && !reset_on_fork) |
6026 |
++ return -EPERM; |
6027 |
++ } |
6028 |
++ |
6029 |
++ if (user) { |
6030 |
++ retval = security_task_setscheduler(p); |
6031 |
++ if (retval) |
6032 |
++ return retval; |
6033 |
++ } |
6034 |
++ |
6035 |
++ if (pi) |
6036 |
++ cpuset_read_lock(); |
6037 |
++ |
6038 |
++ /* |
6039 |
++ * Make sure no PI-waiters arrive (or leave) while we are |
6040 |
++ * changing the priority of the task: |
6041 |
++ */ |
6042 |
++ raw_spin_lock_irqsave(&p->pi_lock, flags); |
6043 |
++ |
6044 |
++ /* |
6045 |
++ * To be able to change p->policy safely, task_access_lock() |
6046 |
++ * must be called. |
6047 |
++ * IF use task_access_lock() here: |
6048 |
++ * For the task p which is not running, reading rq->stop is |
6049 |
++ * racy but acceptable as ->stop doesn't change much. |
6050 |
++ * An enhancemnet can be made to read rq->stop saftly. |
6051 |
++ */ |
6052 |
++ rq = __task_access_lock(p, &lock); |
6053 |
++ |
6054 |
++ /* |
6055 |
++ * Changing the policy of the stop threads its a very bad idea |
6056 |
++ */ |
6057 |
++ if (p == rq->stop) { |
6058 |
++ retval = -EINVAL; |
6059 |
++ goto unlock; |
6060 |
++ } |
6061 |
++ |
6062 |
++ /* |
6063 |
++ * If not changing anything there's no need to proceed further: |
6064 |
++ */ |
6065 |
++ if (unlikely(policy == p->policy)) { |
6066 |
++ if (rt_policy(policy) && attr->sched_priority != p->rt_priority) |
6067 |
++ goto change; |
6068 |
++ if (!rt_policy(policy) && |
6069 |
++ NICE_TO_PRIO(attr->sched_nice) != p->static_prio) |
6070 |
++ goto change; |
6071 |
++ |
6072 |
++ p->sched_reset_on_fork = reset_on_fork; |
6073 |
++ retval = 0; |
6074 |
++ goto unlock; |
6075 |
++ } |
6076 |
++change: |
6077 |
++ |
6078 |
++ /* Re-check policy now with rq lock held */ |
6079 |
++ if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { |
6080 |
++ policy = oldpolicy = -1; |
6081 |
++ __task_access_unlock(p, lock); |
6082 |
++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
6083 |
++ if (pi) |
6084 |
++ cpuset_read_unlock(); |
6085 |
++ goto recheck; |
6086 |
++ } |
6087 |
++ |
6088 |
++ p->sched_reset_on_fork = reset_on_fork; |
6089 |
++ |
6090 |
++ newprio = __normal_prio(policy, attr->sched_priority, NICE_TO_PRIO(attr->sched_nice)); |
6091 |
++ if (pi) { |
6092 |
++ /* |
6093 |
++ * Take priority boosted tasks into account. If the new |
6094 |
++ * effective priority is unchanged, we just store the new |
6095 |
++ * normal parameters and do not touch the scheduler class and |
6096 |
++ * the runqueue. This will be done when the task deboost |
6097 |
++ * itself. |
6098 |
++ */ |
6099 |
++ newprio = rt_effective_prio(p, newprio); |
6100 |
++ } |
6101 |
++ |
6102 |
++ if (!(attr->sched_flags & SCHED_FLAG_KEEP_PARAMS)) { |
6103 |
++ __setscheduler_params(p, attr); |
6104 |
++ __setscheduler_prio(p, newprio); |
6105 |
++ } |
6106 |
++ |
6107 |
++ check_task_changed(p, rq); |
6108 |
++ |
6109 |
++ /* Avoid rq from going away on us: */ |
6110 |
++ preempt_disable(); |
6111 |
++ head = splice_balance_callbacks(rq); |
6112 |
++ __task_access_unlock(p, lock); |
6113 |
++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
6114 |
++ |
6115 |
++ if (pi) { |
6116 |
++ cpuset_read_unlock(); |
6117 |
++ rt_mutex_adjust_pi(p); |
6118 |
++ } |
6119 |
++ |
6120 |
++ /* Run balance callbacks after we've adjusted the PI chain: */ |
6121 |
++ balance_callbacks(rq, head); |
6122 |
++ preempt_enable(); |
6123 |
++ |
6124 |
++ return 0; |
6125 |
++ |
6126 |
++unlock: |
6127 |
++ __task_access_unlock(p, lock); |
6128 |
++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
6129 |
++ if (pi) |
6130 |
++ cpuset_read_unlock(); |
6131 |
++ return retval; |
6132 |
++} |
6133 |
++ |
6134 |
++static int _sched_setscheduler(struct task_struct *p, int policy, |
6135 |
++ const struct sched_param *param, bool check) |
6136 |
++{ |
6137 |
++ struct sched_attr attr = { |
6138 |
++ .sched_policy = policy, |
6139 |
++ .sched_priority = param->sched_priority, |
6140 |
++ .sched_nice = PRIO_TO_NICE(p->static_prio), |
6141 |
++ }; |
6142 |
++ |
6143 |
++ /* Fixup the legacy SCHED_RESET_ON_FORK hack. */ |
6144 |
++ if ((policy != SETPARAM_POLICY) && (policy & SCHED_RESET_ON_FORK)) { |
6145 |
++ attr.sched_flags |= SCHED_FLAG_RESET_ON_FORK; |
6146 |
++ policy &= ~SCHED_RESET_ON_FORK; |
6147 |
++ attr.sched_policy = policy; |
6148 |
++ } |
6149 |
++ |
6150 |
++ return __sched_setscheduler(p, &attr, check, true); |
6151 |
++} |
6152 |
++ |
6153 |
++/** |
6154 |
++ * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. |
6155 |
++ * @p: the task in question. |
6156 |
++ * @policy: new policy. |
6157 |
++ * @param: structure containing the new RT priority. |
6158 |
++ * |
6159 |
++ * Use sched_set_fifo(), read its comment. |
6160 |
++ * |
6161 |
++ * Return: 0 on success. An error code otherwise. |
6162 |
++ * |
6163 |
++ * NOTE that the task may be already dead. |
6164 |
++ */ |
6165 |
++int sched_setscheduler(struct task_struct *p, int policy, |
6166 |
++ const struct sched_param *param) |
6167 |
++{ |
6168 |
++ return _sched_setscheduler(p, policy, param, true); |
6169 |
++} |
6170 |
++ |
6171 |
++int sched_setattr(struct task_struct *p, const struct sched_attr *attr) |
6172 |
++{ |
6173 |
++ return __sched_setscheduler(p, attr, true, true); |
6174 |
++} |
6175 |
++ |
6176 |
++int sched_setattr_nocheck(struct task_struct *p, const struct sched_attr *attr) |
6177 |
++{ |
6178 |
++ return __sched_setscheduler(p, attr, false, true); |
6179 |
++} |
6180 |
++EXPORT_SYMBOL_GPL(sched_setattr_nocheck); |
6181 |
++ |
6182 |
++/** |
6183 |
++ * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. |
6184 |
++ * @p: the task in question. |
6185 |
++ * @policy: new policy. |
6186 |
++ * @param: structure containing the new RT priority. |
6187 |
++ * |
6188 |
++ * Just like sched_setscheduler, only don't bother checking if the |
6189 |
++ * current context has permission. For example, this is needed in |
6190 |
++ * stop_machine(): we create temporary high priority worker threads, |
6191 |
++ * but our caller might not have that capability. |
6192 |
++ * |
6193 |
++ * Return: 0 on success. An error code otherwise. |
6194 |
++ */ |
6195 |
++int sched_setscheduler_nocheck(struct task_struct *p, int policy, |
6196 |
++ const struct sched_param *param) |
6197 |
++{ |
6198 |
++ return _sched_setscheduler(p, policy, param, false); |
6199 |
++} |
6200 |
++ |
6201 |
++/* |
6202 |
++ * SCHED_FIFO is a broken scheduler model; that is, it is fundamentally |
6203 |
++ * incapable of resource management, which is the one thing an OS really should |
6204 |
++ * be doing. |
6205 |
++ * |
6206 |
++ * This is of course the reason it is limited to privileged users only. |
6207 |
++ * |
6208 |
++ * Worse still; it is fundamentally impossible to compose static priority |
6209 |
++ * workloads. You cannot take two correctly working static prio workloads |
6210 |
++ * and smash them together and still expect them to work. |
6211 |
++ * |
6212 |
++ * For this reason 'all' FIFO tasks the kernel creates are basically at: |
6213 |
++ * |
6214 |
++ * MAX_RT_PRIO / 2 |
6215 |
++ * |
6216 |
++ * The administrator _MUST_ configure the system, the kernel simply doesn't |
6217 |
++ * know enough information to make a sensible choice. |
6218 |
++ */ |
6219 |
++void sched_set_fifo(struct task_struct *p) |
6220 |
++{ |
6221 |
++ struct sched_param sp = { .sched_priority = MAX_RT_PRIO / 2 }; |
6222 |
++ WARN_ON_ONCE(sched_setscheduler_nocheck(p, SCHED_FIFO, &sp) != 0); |
6223 |
++} |
6224 |
++EXPORT_SYMBOL_GPL(sched_set_fifo); |
6225 |
++ |
6226 |
++/* |
6227 |
++ * For when you don't much care about FIFO, but want to be above SCHED_NORMAL. |
6228 |
++ */ |
6229 |
++void sched_set_fifo_low(struct task_struct *p) |
6230 |
++{ |
6231 |
++ struct sched_param sp = { .sched_priority = 1 }; |
6232 |
++ WARN_ON_ONCE(sched_setscheduler_nocheck(p, SCHED_FIFO, &sp) != 0); |
6233 |
++} |
6234 |
++EXPORT_SYMBOL_GPL(sched_set_fifo_low); |
6235 |
++ |
6236 |
++void sched_set_normal(struct task_struct *p, int nice) |
6237 |
++{ |
6238 |
++ struct sched_attr attr = { |
6239 |
++ .sched_policy = SCHED_NORMAL, |
6240 |
++ .sched_nice = nice, |
6241 |
++ }; |
6242 |
++ WARN_ON_ONCE(sched_setattr_nocheck(p, &attr) != 0); |
6243 |
++} |
6244 |
++EXPORT_SYMBOL_GPL(sched_set_normal); |
6245 |
++ |
6246 |
++static int |
6247 |
++do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) |
6248 |
++{ |
6249 |
++ struct sched_param lparam; |
6250 |
++ struct task_struct *p; |
6251 |
++ int retval; |
6252 |
++ |
6253 |
++ if (!param || pid < 0) |
6254 |
++ return -EINVAL; |
6255 |
++ if (copy_from_user(&lparam, param, sizeof(struct sched_param))) |
6256 |
++ return -EFAULT; |
6257 |
++ |
6258 |
++ rcu_read_lock(); |
6259 |
++ retval = -ESRCH; |
6260 |
++ p = find_process_by_pid(pid); |
6261 |
++ if (likely(p)) |
6262 |
++ get_task_struct(p); |
6263 |
++ rcu_read_unlock(); |
6264 |
++ |
6265 |
++ if (likely(p)) { |
6266 |
++ retval = sched_setscheduler(p, policy, &lparam); |
6267 |
++ put_task_struct(p); |
6268 |
++ } |
6269 |
++ |
6270 |
++ return retval; |
6271 |
++} |
6272 |
++ |
6273 |
++/* |
6274 |
++ * Mimics kernel/events/core.c perf_copy_attr(). |
6275 |
++ */ |
6276 |
++static int sched_copy_attr(struct sched_attr __user *uattr, struct sched_attr *attr) |
6277 |
++{ |
6278 |
++ u32 size; |
6279 |
++ int ret; |
6280 |
++ |
6281 |
++ /* Zero the full structure, so that a short copy will be nice: */ |
6282 |
++ memset(attr, 0, sizeof(*attr)); |
6283 |
++ |
6284 |
++ ret = get_user(size, &uattr->size); |
6285 |
++ if (ret) |
6286 |
++ return ret; |
6287 |
++ |
6288 |
++ /* ABI compatibility quirk: */ |
6289 |
++ if (!size) |
6290 |
++ size = SCHED_ATTR_SIZE_VER0; |
6291 |
++ |
6292 |
++ if (size < SCHED_ATTR_SIZE_VER0 || size > PAGE_SIZE) |
6293 |
++ goto err_size; |
6294 |
++ |
6295 |
++ ret = copy_struct_from_user(attr, sizeof(*attr), uattr, size); |
6296 |
++ if (ret) { |
6297 |
++ if (ret == -E2BIG) |
6298 |
++ goto err_size; |
6299 |
++ return ret; |
6300 |
++ } |
6301 |
++ |
6302 |
++ /* |
6303 |
++ * XXX: Do we want to be lenient like existing syscalls; or do we want |
6304 |
++ * to be strict and return an error on out-of-bounds values? |
6305 |
++ */ |
6306 |
++ attr->sched_nice = clamp(attr->sched_nice, -20, 19); |
6307 |
++ |
6308 |
++ /* sched/core.c uses zero here but we already know ret is zero */ |
6309 |
++ return 0; |
6310 |
++ |
6311 |
++err_size: |
6312 |
++ put_user(sizeof(*attr), &uattr->size); |
6313 |
++ return -E2BIG; |
6314 |
++} |
6315 |
++ |
6316 |
++/** |
6317 |
++ * sys_sched_setscheduler - set/change the scheduler policy and RT priority |
6318 |
++ * @pid: the pid in question. |
6319 |
++ * @policy: new policy. |
6320 |
++ * |
6321 |
++ * Return: 0 on success. An error code otherwise. |
6322 |
++ * @param: structure containing the new RT priority. |
6323 |
++ */ |
6324 |
++SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, struct sched_param __user *, param) |
6325 |
++{ |
6326 |
++ if (policy < 0) |
6327 |
++ return -EINVAL; |
6328 |
++ |
6329 |
++ return do_sched_setscheduler(pid, policy, param); |
6330 |
++} |
6331 |
++ |
6332 |
++/** |
6333 |
++ * sys_sched_setparam - set/change the RT priority of a thread |
6334 |
++ * @pid: the pid in question. |
6335 |
++ * @param: structure containing the new RT priority. |
6336 |
++ * |
6337 |
++ * Return: 0 on success. An error code otherwise. |
6338 |
++ */ |
6339 |
++SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) |
6340 |
++{ |
6341 |
++ return do_sched_setscheduler(pid, SETPARAM_POLICY, param); |
6342 |
++} |
6343 |
++ |
6344 |
++/** |
6345 |
++ * sys_sched_setattr - same as above, but with extended sched_attr |
6346 |
++ * @pid: the pid in question. |
6347 |
++ * @uattr: structure containing the extended parameters. |
6348 |
++ */ |
6349 |
++SYSCALL_DEFINE3(sched_setattr, pid_t, pid, struct sched_attr __user *, uattr, |
6350 |
++ unsigned int, flags) |
6351 |
++{ |
6352 |
++ struct sched_attr attr; |
6353 |
++ struct task_struct *p; |
6354 |
++ int retval; |
6355 |
++ |
6356 |
++ if (!uattr || pid < 0 || flags) |
6357 |
++ return -EINVAL; |
6358 |
++ |
6359 |
++ retval = sched_copy_attr(uattr, &attr); |
6360 |
++ if (retval) |
6361 |
++ return retval; |
6362 |
++ |
6363 |
++ if ((int)attr.sched_policy < 0) |
6364 |
++ return -EINVAL; |
6365 |
++ |
6366 |
++ rcu_read_lock(); |
6367 |
++ retval = -ESRCH; |
6368 |
++ p = find_process_by_pid(pid); |
6369 |
++ if (likely(p)) |
6370 |
++ get_task_struct(p); |
6371 |
++ rcu_read_unlock(); |
6372 |
++ |
6373 |
++ if (likely(p)) { |
6374 |
++ retval = sched_setattr(p, &attr); |
6375 |
++ put_task_struct(p); |
6376 |
++ } |
6377 |
++ |
6378 |
++ return retval; |
6379 |
++} |
6380 |
++ |
6381 |
++/** |
6382 |
++ * sys_sched_getscheduler - get the policy (scheduling class) of a thread |
6383 |
++ * @pid: the pid in question. |
6384 |
++ * |
6385 |
++ * Return: On success, the policy of the thread. Otherwise, a negative error |
6386 |
++ * code. |
6387 |
++ */ |
6388 |
++SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) |
6389 |
++{ |
6390 |
++ struct task_struct *p; |
6391 |
++ int retval = -EINVAL; |
6392 |
++ |
6393 |
++ if (pid < 0) |
6394 |
++ goto out_nounlock; |
6395 |
++ |
6396 |
++ retval = -ESRCH; |
6397 |
++ rcu_read_lock(); |
6398 |
++ p = find_process_by_pid(pid); |
6399 |
++ if (p) { |
6400 |
++ retval = security_task_getscheduler(p); |
6401 |
++ if (!retval) |
6402 |
++ retval = p->policy; |
6403 |
++ } |
6404 |
++ rcu_read_unlock(); |
6405 |
++ |
6406 |
++out_nounlock: |
6407 |
++ return retval; |
6408 |
++} |
6409 |
++ |
6410 |
++/** |
6411 |
++ * sys_sched_getscheduler - get the RT priority of a thread |
6412 |
++ * @pid: the pid in question. |
6413 |
++ * @param: structure containing the RT priority. |
6414 |
++ * |
6415 |
++ * Return: On success, 0 and the RT priority is in @param. Otherwise, an error |
6416 |
++ * code. |
6417 |
++ */ |
6418 |
++SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) |
6419 |
++{ |
6420 |
++ struct sched_param lp = { .sched_priority = 0 }; |
6421 |
++ struct task_struct *p; |
6422 |
++ int retval = -EINVAL; |
6423 |
++ |
6424 |
++ if (!param || pid < 0) |
6425 |
++ goto out_nounlock; |
6426 |
++ |
6427 |
++ rcu_read_lock(); |
6428 |
++ p = find_process_by_pid(pid); |
6429 |
++ retval = -ESRCH; |
6430 |
++ if (!p) |
6431 |
++ goto out_unlock; |
6432 |
++ |
6433 |
++ retval = security_task_getscheduler(p); |
6434 |
++ if (retval) |
6435 |
++ goto out_unlock; |
6436 |
++ |
6437 |
++ if (task_has_rt_policy(p)) |
6438 |
++ lp.sched_priority = p->rt_priority; |
6439 |
++ rcu_read_unlock(); |
6440 |
++ |
6441 |
++ /* |
6442 |
++ * This one might sleep, we cannot do it with a spinlock held ... |
6443 |
++ */ |
6444 |
++ retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; |
6445 |
++ |
6446 |
++out_nounlock: |
6447 |
++ return retval; |
6448 |
++ |
6449 |
++out_unlock: |
6450 |
++ rcu_read_unlock(); |
6451 |
++ return retval; |
6452 |
++} |
6453 |
++ |
6454 |
++/* |
6455 |
++ * Copy the kernel size attribute structure (which might be larger |
6456 |
++ * than what user-space knows about) to user-space. |
6457 |
++ * |
6458 |
++ * Note that all cases are valid: user-space buffer can be larger or |
6459 |
++ * smaller than the kernel-space buffer. The usual case is that both |
6460 |
++ * have the same size. |
6461 |
++ */ |
6462 |
++static int |
6463 |
++sched_attr_copy_to_user(struct sched_attr __user *uattr, |
6464 |
++ struct sched_attr *kattr, |
6465 |
++ unsigned int usize) |
6466 |
++{ |
6467 |
++ unsigned int ksize = sizeof(*kattr); |
6468 |
++ |
6469 |
++ if (!access_ok(uattr, usize)) |
6470 |
++ return -EFAULT; |
6471 |
++ |
6472 |
++ /* |
6473 |
++ * sched_getattr() ABI forwards and backwards compatibility: |
6474 |
++ * |
6475 |
++ * If usize == ksize then we just copy everything to user-space and all is good. |
6476 |
++ * |
6477 |
++ * If usize < ksize then we only copy as much as user-space has space for, |
6478 |
++ * this keeps ABI compatibility as well. We skip the rest. |
6479 |
++ * |
6480 |
++ * If usize > ksize then user-space is using a newer version of the ABI, |
6481 |
++ * which part the kernel doesn't know about. Just ignore it - tooling can |
6482 |
++ * detect the kernel's knowledge of attributes from the attr->size value |
6483 |
++ * which is set to ksize in this case. |
6484 |
++ */ |
6485 |
++ kattr->size = min(usize, ksize); |
6486 |
++ |
6487 |
++ if (copy_to_user(uattr, kattr, kattr->size)) |
6488 |
++ return -EFAULT; |
6489 |
++ |
6490 |
++ return 0; |
6491 |
++} |
6492 |
++ |
6493 |
++/** |
6494 |
++ * sys_sched_getattr - similar to sched_getparam, but with sched_attr |
6495 |
++ * @pid: the pid in question. |
6496 |
++ * @uattr: structure containing the extended parameters. |
6497 |
++ * @usize: sizeof(attr) for fwd/bwd comp. |
6498 |
++ * @flags: for future extension. |
6499 |
++ */ |
6500 |
++SYSCALL_DEFINE4(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr, |
6501 |
++ unsigned int, usize, unsigned int, flags) |
6502 |
++{ |
6503 |
++ struct sched_attr kattr = { }; |
6504 |
++ struct task_struct *p; |
6505 |
++ int retval; |
6506 |
++ |
6507 |
++ if (!uattr || pid < 0 || usize > PAGE_SIZE || |
6508 |
++ usize < SCHED_ATTR_SIZE_VER0 || flags) |
6509 |
++ return -EINVAL; |
6510 |
++ |
6511 |
++ rcu_read_lock(); |
6512 |
++ p = find_process_by_pid(pid); |
6513 |
++ retval = -ESRCH; |
6514 |
++ if (!p) |
6515 |
++ goto out_unlock; |
6516 |
++ |
6517 |
++ retval = security_task_getscheduler(p); |
6518 |
++ if (retval) |
6519 |
++ goto out_unlock; |
6520 |
++ |
6521 |
++ kattr.sched_policy = p->policy; |
6522 |
++ if (p->sched_reset_on_fork) |
6523 |
++ kattr.sched_flags |= SCHED_FLAG_RESET_ON_FORK; |
6524 |
++ if (task_has_rt_policy(p)) |
6525 |
++ kattr.sched_priority = p->rt_priority; |
6526 |
++ else |
6527 |
++ kattr.sched_nice = task_nice(p); |
6528 |
++ kattr.sched_flags &= SCHED_FLAG_ALL; |
6529 |
++ |
6530 |
++#ifdef CONFIG_UCLAMP_TASK |
6531 |
++ kattr.sched_util_min = p->uclamp_req[UCLAMP_MIN].value; |
6532 |
++ kattr.sched_util_max = p->uclamp_req[UCLAMP_MAX].value; |
6533 |
++#endif |
6534 |
++ |
6535 |
++ rcu_read_unlock(); |
6536 |
++ |
6537 |
++ return sched_attr_copy_to_user(uattr, &kattr, usize); |
6538 |
++ |
6539 |
++out_unlock: |
6540 |
++ rcu_read_unlock(); |
6541 |
++ return retval; |
6542 |
++} |
6543 |
++ |
6544 |
++static int |
6545 |
++__sched_setaffinity(struct task_struct *p, const struct cpumask *mask) |
6546 |
++{ |
6547 |
++ int retval; |
6548 |
++ cpumask_var_t cpus_allowed, new_mask; |
6549 |
++ |
6550 |
++ if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) |
6551 |
++ return -ENOMEM; |
6552 |
++ |
6553 |
++ if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { |
6554 |
++ retval = -ENOMEM; |
6555 |
++ goto out_free_cpus_allowed; |
6556 |
++ } |
6557 |
++ |
6558 |
++ cpuset_cpus_allowed(p, cpus_allowed); |
6559 |
++ cpumask_and(new_mask, mask, cpus_allowed); |
6560 |
++again: |
6561 |
++ retval = __set_cpus_allowed_ptr(p, new_mask, SCA_CHECK | SCA_USER); |
6562 |
++ if (retval) |
6563 |
++ goto out_free_new_mask; |
6564 |
++ |
6565 |
++ cpuset_cpus_allowed(p, cpus_allowed); |
6566 |
++ if (!cpumask_subset(new_mask, cpus_allowed)) { |
6567 |
++ /* |
6568 |
++ * We must have raced with a concurrent cpuset |
6569 |
++ * update. Just reset the cpus_allowed to the |
6570 |
++ * cpuset's cpus_allowed |
6571 |
++ */ |
6572 |
++ cpumask_copy(new_mask, cpus_allowed); |
6573 |
++ goto again; |
6574 |
++ } |
6575 |
++ |
6576 |
++out_free_new_mask: |
6577 |
++ free_cpumask_var(new_mask); |
6578 |
++out_free_cpus_allowed: |
6579 |
++ free_cpumask_var(cpus_allowed); |
6580 |
++ return retval; |
6581 |
++} |
6582 |
++ |
6583 |
++long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) |
6584 |
++{ |
6585 |
++ struct task_struct *p; |
6586 |
++ int retval; |
6587 |
++ |
6588 |
++ rcu_read_lock(); |
6589 |
++ |
6590 |
++ p = find_process_by_pid(pid); |
6591 |
++ if (!p) { |
6592 |
++ rcu_read_unlock(); |
6593 |
++ return -ESRCH; |
6594 |
++ } |
6595 |
++ |
6596 |
++ /* Prevent p going away */ |
6597 |
++ get_task_struct(p); |
6598 |
++ rcu_read_unlock(); |
6599 |
++ |
6600 |
++ if (p->flags & PF_NO_SETAFFINITY) { |
6601 |
++ retval = -EINVAL; |
6602 |
++ goto out_put_task; |
6603 |
++ } |
6604 |
++ |
6605 |
++ if (!check_same_owner(p)) { |
6606 |
++ rcu_read_lock(); |
6607 |
++ if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) { |
6608 |
++ rcu_read_unlock(); |
6609 |
++ retval = -EPERM; |
6610 |
++ goto out_put_task; |
6611 |
++ } |
6612 |
++ rcu_read_unlock(); |
6613 |
++ } |
6614 |
++ |
6615 |
++ retval = security_task_setscheduler(p); |
6616 |
++ if (retval) |
6617 |
++ goto out_put_task; |
6618 |
++ |
6619 |
++ retval = __sched_setaffinity(p, in_mask); |
6620 |
++out_put_task: |
6621 |
++ put_task_struct(p); |
6622 |
++ return retval; |
6623 |
++} |
6624 |
++ |
6625 |
++static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, |
6626 |
++ struct cpumask *new_mask) |
6627 |
++{ |
6628 |
++ if (len < cpumask_size()) |
6629 |
++ cpumask_clear(new_mask); |
6630 |
++ else if (len > cpumask_size()) |
6631 |
++ len = cpumask_size(); |
6632 |
++ |
6633 |
++ return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; |
6634 |
++} |
6635 |
++ |
6636 |
++/** |
6637 |
++ * sys_sched_setaffinity - set the CPU affinity of a process |
6638 |
++ * @pid: pid of the process |
6639 |
++ * @len: length in bytes of the bitmask pointed to by user_mask_ptr |
6640 |
++ * @user_mask_ptr: user-space pointer to the new CPU mask |
6641 |
++ * |
6642 |
++ * Return: 0 on success. An error code otherwise. |
6643 |
++ */ |
6644 |
++SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, |
6645 |
++ unsigned long __user *, user_mask_ptr) |
6646 |
++{ |
6647 |
++ cpumask_var_t new_mask; |
6648 |
++ int retval; |
6649 |
++ |
6650 |
++ if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) |
6651 |
++ return -ENOMEM; |
6652 |
++ |
6653 |
++ retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); |
6654 |
++ if (retval == 0) |
6655 |
++ retval = sched_setaffinity(pid, new_mask); |
6656 |
++ free_cpumask_var(new_mask); |
6657 |
++ return retval; |
6658 |
++} |
6659 |
++ |
6660 |
++long sched_getaffinity(pid_t pid, cpumask_t *mask) |
6661 |
++{ |
6662 |
++ struct task_struct *p; |
6663 |
++ raw_spinlock_t *lock; |
6664 |
++ unsigned long flags; |
6665 |
++ int retval; |
6666 |
++ |
6667 |
++ rcu_read_lock(); |
6668 |
++ |
6669 |
++ retval = -ESRCH; |
6670 |
++ p = find_process_by_pid(pid); |
6671 |
++ if (!p) |
6672 |
++ goto out_unlock; |
6673 |
++ |
6674 |
++ retval = security_task_getscheduler(p); |
6675 |
++ if (retval) |
6676 |
++ goto out_unlock; |
6677 |
++ |
6678 |
++ task_access_lock_irqsave(p, &lock, &flags); |
6679 |
++ cpumask_and(mask, &p->cpus_mask, cpu_active_mask); |
6680 |
++ task_access_unlock_irqrestore(p, lock, &flags); |
6681 |
++ |
6682 |
++out_unlock: |
6683 |
++ rcu_read_unlock(); |
6684 |
++ |
6685 |
++ return retval; |
6686 |
++} |
6687 |
++ |
6688 |
++/** |
6689 |
++ * sys_sched_getaffinity - get the CPU affinity of a process |
6690 |
++ * @pid: pid of the process |
6691 |
++ * @len: length in bytes of the bitmask pointed to by user_mask_ptr |
6692 |
++ * @user_mask_ptr: user-space pointer to hold the current CPU mask |
6693 |
++ * |
6694 |
++ * Return: size of CPU mask copied to user_mask_ptr on success. An |
6695 |
++ * error code otherwise. |
6696 |
++ */ |
6697 |
++SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, |
6698 |
++ unsigned long __user *, user_mask_ptr) |
6699 |
++{ |
6700 |
++ int ret; |
6701 |
++ cpumask_var_t mask; |
6702 |
++ |
6703 |
++ if ((len * BITS_PER_BYTE) < nr_cpu_ids) |
6704 |
++ return -EINVAL; |
6705 |
++ if (len & (sizeof(unsigned long)-1)) |
6706 |
++ return -EINVAL; |
6707 |
++ |
6708 |
++ if (!alloc_cpumask_var(&mask, GFP_KERNEL)) |
6709 |
++ return -ENOMEM; |
6710 |
++ |
6711 |
++ ret = sched_getaffinity(pid, mask); |
6712 |
++ if (ret == 0) { |
6713 |
++ unsigned int retlen = min_t(size_t, len, cpumask_size()); |
6714 |
++ |
6715 |
++ if (copy_to_user(user_mask_ptr, mask, retlen)) |
6716 |
++ ret = -EFAULT; |
6717 |
++ else |
6718 |
++ ret = retlen; |
6719 |
++ } |
6720 |
++ free_cpumask_var(mask); |
6721 |
++ |
6722 |
++ return ret; |
6723 |
++} |
6724 |
++ |
6725 |
++static void do_sched_yield(void) |
6726 |
++{ |
6727 |
++ struct rq *rq; |
6728 |
++ struct rq_flags rf; |
6729 |
++ |
6730 |
++ if (!sched_yield_type) |
6731 |
++ return; |
6732 |
++ |
6733 |
++ rq = this_rq_lock_irq(&rf); |
6734 |
++ |
6735 |
++ schedstat_inc(rq->yld_count); |
6736 |
++ |
6737 |
++ if (1 == sched_yield_type) { |
6738 |
++ if (!rt_task(current)) |
6739 |
++ do_sched_yield_type_1(current, rq); |
6740 |
++ } else if (2 == sched_yield_type) { |
6741 |
++ if (rq->nr_running > 1) |
6742 |
++ rq->skip = current; |
6743 |
++ } |
6744 |
++ |
6745 |
++ preempt_disable(); |
6746 |
++ raw_spin_unlock_irq(&rq->lock); |
6747 |
++ sched_preempt_enable_no_resched(); |
6748 |
++ |
6749 |
++ schedule(); |
6750 |
++} |
6751 |
++ |
6752 |
++/** |
6753 |
++ * sys_sched_yield - yield the current processor to other threads. |
6754 |
++ * |
6755 |
++ * This function yields the current CPU to other tasks. If there are no |
6756 |
++ * other threads running on this CPU then this function will return. |
6757 |
++ * |
6758 |
++ * Return: 0. |
6759 |
++ */ |
6760 |
++SYSCALL_DEFINE0(sched_yield) |
6761 |
++{ |
6762 |
++ do_sched_yield(); |
6763 |
++ return 0; |
6764 |
++} |
6765 |
++ |
6766 |
++#if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) |
6767 |
++int __sched __cond_resched(void) |
6768 |
++{ |
6769 |
++ if (should_resched(0)) { |
6770 |
++ preempt_schedule_common(); |
6771 |
++ return 1; |
6772 |
++ } |
6773 |
++ /* |
6774 |
++ * In preemptible kernels, ->rcu_read_lock_nesting tells the tick |
6775 |
++ * whether the current CPU is in an RCU read-side critical section, |
6776 |
++ * so the tick can report quiescent states even for CPUs looping |
6777 |
++ * in kernel context. In contrast, in non-preemptible kernels, |
6778 |
++ * RCU readers leave no in-memory hints, which means that CPU-bound |
6779 |
++ * processes executing in kernel context might never report an |
6780 |
++ * RCU quiescent state. Therefore, the following code causes |
6781 |
++ * cond_resched() to report a quiescent state, but only when RCU |
6782 |
++ * is in urgent need of one. |
6783 |
++ */ |
6784 |
++#ifndef CONFIG_PREEMPT_RCU |
6785 |
++ rcu_all_qs(); |
6786 |
++#endif |
6787 |
++ return 0; |
6788 |
++} |
6789 |
++EXPORT_SYMBOL(__cond_resched); |
6790 |
++#endif |
6791 |
++ |
6792 |
++#ifdef CONFIG_PREEMPT_DYNAMIC |
6793 |
++#if defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) |
6794 |
++#define cond_resched_dynamic_enabled __cond_resched |
6795 |
++#define cond_resched_dynamic_disabled ((void *)&__static_call_return0) |
6796 |
++DEFINE_STATIC_CALL_RET0(cond_resched, __cond_resched); |
6797 |
++EXPORT_STATIC_CALL_TRAMP(cond_resched); |
6798 |
++ |
6799 |
++#define might_resched_dynamic_enabled __cond_resched |
6800 |
++#define might_resched_dynamic_disabled ((void *)&__static_call_return0) |
6801 |
++DEFINE_STATIC_CALL_RET0(might_resched, __cond_resched); |
6802 |
++EXPORT_STATIC_CALL_TRAMP(might_resched); |
6803 |
++#elif defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) |
6804 |
++static DEFINE_STATIC_KEY_FALSE(sk_dynamic_cond_resched); |
6805 |
++int __sched dynamic_cond_resched(void) |
6806 |
++{ |
6807 |
++ if (!static_branch_unlikely(&sk_dynamic_cond_resched)) |
6808 |
++ return 0; |
6809 |
++ return __cond_resched(); |
6810 |
++} |
6811 |
++EXPORT_SYMBOL(dynamic_cond_resched); |
6812 |
++ |
6813 |
++static DEFINE_STATIC_KEY_FALSE(sk_dynamic_might_resched); |
6814 |
++int __sched dynamic_might_resched(void) |
6815 |
++{ |
6816 |
++ if (!static_branch_unlikely(&sk_dynamic_might_resched)) |
6817 |
++ return 0; |
6818 |
++ return __cond_resched(); |
6819 |
++} |
6820 |
++EXPORT_SYMBOL(dynamic_might_resched); |
6821 |
++#endif |
6822 |
++#endif |
6823 |
++ |
6824 |
++/* |
6825 |
++ * __cond_resched_lock() - if a reschedule is pending, drop the given lock, |
6826 |
++ * call schedule, and on return reacquire the lock. |
6827 |
++ * |
6828 |
++ * This works OK both with and without CONFIG_PREEMPTION. We do strange low-level |
6829 |
++ * operations here to prevent schedule() from being called twice (once via |
6830 |
++ * spin_unlock(), once by hand). |
6831 |
++ */ |
6832 |
++int __cond_resched_lock(spinlock_t *lock) |
6833 |
++{ |
6834 |
++ int resched = should_resched(PREEMPT_LOCK_OFFSET); |
6835 |
++ int ret = 0; |
6836 |
++ |
6837 |
++ lockdep_assert_held(lock); |
6838 |
++ |
6839 |
++ if (spin_needbreak(lock) || resched) { |
6840 |
++ spin_unlock(lock); |
6841 |
++ if (!_cond_resched()) |
6842 |
++ cpu_relax(); |
6843 |
++ ret = 1; |
6844 |
++ spin_lock(lock); |
6845 |
++ } |
6846 |
++ return ret; |
6847 |
++} |
6848 |
++EXPORT_SYMBOL(__cond_resched_lock); |
6849 |
++ |
6850 |
++int __cond_resched_rwlock_read(rwlock_t *lock) |
6851 |
++{ |
6852 |
++ int resched = should_resched(PREEMPT_LOCK_OFFSET); |
6853 |
++ int ret = 0; |
6854 |
++ |
6855 |
++ lockdep_assert_held_read(lock); |
6856 |
++ |
6857 |
++ if (rwlock_needbreak(lock) || resched) { |
6858 |
++ read_unlock(lock); |
6859 |
++ if (!_cond_resched()) |
6860 |
++ cpu_relax(); |
6861 |
++ ret = 1; |
6862 |
++ read_lock(lock); |
6863 |
++ } |
6864 |
++ return ret; |
6865 |
++} |
6866 |
++EXPORT_SYMBOL(__cond_resched_rwlock_read); |
6867 |
++ |
6868 |
++int __cond_resched_rwlock_write(rwlock_t *lock) |
6869 |
++{ |
6870 |
++ int resched = should_resched(PREEMPT_LOCK_OFFSET); |
6871 |
++ int ret = 0; |
6872 |
++ |
6873 |
++ lockdep_assert_held_write(lock); |
6874 |
++ |
6875 |
++ if (rwlock_needbreak(lock) || resched) { |
6876 |
++ write_unlock(lock); |
6877 |
++ if (!_cond_resched()) |
6878 |
++ cpu_relax(); |
6879 |
++ ret = 1; |
6880 |
++ write_lock(lock); |
6881 |
++ } |
6882 |
++ return ret; |
6883 |
++} |
6884 |
++EXPORT_SYMBOL(__cond_resched_rwlock_write); |
6885 |
++ |
6886 |
++#ifdef CONFIG_PREEMPT_DYNAMIC |
6887 |
++ |
6888 |
++#ifdef CONFIG_GENERIC_ENTRY |
6889 |
++#include <linux/entry-common.h> |
6890 |
++#endif |
6891 |
++ |
6892 |
++/* |
6893 |
++ * SC:cond_resched |
6894 |
++ * SC:might_resched |
6895 |
++ * SC:preempt_schedule |
6896 |
++ * SC:preempt_schedule_notrace |
6897 |
++ * SC:irqentry_exit_cond_resched |
6898 |
++ * |
6899 |
++ * |
6900 |
++ * NONE: |
6901 |
++ * cond_resched <- __cond_resched |
6902 |
++ * might_resched <- RET0 |
6903 |
++ * preempt_schedule <- NOP |
6904 |
++ * preempt_schedule_notrace <- NOP |
6905 |
++ * irqentry_exit_cond_resched <- NOP |
6906 |
++ * |
6907 |
++ * VOLUNTARY: |
6908 |
++ * cond_resched <- __cond_resched |
6909 |
++ * might_resched <- __cond_resched |
6910 |
++ * preempt_schedule <- NOP |
6911 |
++ * preempt_schedule_notrace <- NOP |
6912 |
++ * irqentry_exit_cond_resched <- NOP |
6913 |
++ * |
6914 |
++ * FULL: |
6915 |
++ * cond_resched <- RET0 |
6916 |
++ * might_resched <- RET0 |
6917 |
++ * preempt_schedule <- preempt_schedule |
6918 |
++ * preempt_schedule_notrace <- preempt_schedule_notrace |
6919 |
++ * irqentry_exit_cond_resched <- irqentry_exit_cond_resched |
6920 |
++ */ |
6921 |
++ |
6922 |
++enum { |
6923 |
++ preempt_dynamic_undefined = -1, |
6924 |
++ preempt_dynamic_none, |
6925 |
++ preempt_dynamic_voluntary, |
6926 |
++ preempt_dynamic_full, |
6927 |
++}; |
6928 |
++ |
6929 |
++int preempt_dynamic_mode = preempt_dynamic_undefined; |
6930 |
++ |
6931 |
++int sched_dynamic_mode(const char *str) |
6932 |
++{ |
6933 |
++ if (!strcmp(str, "none")) |
6934 |
++ return preempt_dynamic_none; |
6935 |
++ |
6936 |
++ if (!strcmp(str, "voluntary")) |
6937 |
++ return preempt_dynamic_voluntary; |
6938 |
++ |
6939 |
++ if (!strcmp(str, "full")) |
6940 |
++ return preempt_dynamic_full; |
6941 |
++ |
6942 |
++ return -EINVAL; |
6943 |
++} |
6944 |
++ |
6945 |
++#if defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) |
6946 |
++#define preempt_dynamic_enable(f) static_call_update(f, f##_dynamic_enabled) |
6947 |
++#define preempt_dynamic_disable(f) static_call_update(f, f##_dynamic_disabled) |
6948 |
++#elif defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) |
6949 |
++#define preempt_dynamic_enable(f) static_key_enable(&sk_dynamic_##f.key) |
6950 |
++#define preempt_dynamic_disable(f) static_key_disable(&sk_dynamic_##f.key) |
6951 |
++#else |
6952 |
++#error "Unsupported PREEMPT_DYNAMIC mechanism" |
6953 |
++#endif |
6954 |
++ |
6955 |
++void sched_dynamic_update(int mode) |
6956 |
++{ |
6957 |
++ /* |
6958 |
++ * Avoid {NONE,VOLUNTARY} -> FULL transitions from ever ending up in |
6959 |
++ * the ZERO state, which is invalid. |
6960 |
++ */ |
6961 |
++ preempt_dynamic_enable(cond_resched); |
6962 |
++ preempt_dynamic_enable(might_resched); |
6963 |
++ preempt_dynamic_enable(preempt_schedule); |
6964 |
++ preempt_dynamic_enable(preempt_schedule_notrace); |
6965 |
++ preempt_dynamic_enable(irqentry_exit_cond_resched); |
6966 |
++ |
6967 |
++ switch (mode) { |
6968 |
++ case preempt_dynamic_none: |
6969 |
++ preempt_dynamic_enable(cond_resched); |
6970 |
++ preempt_dynamic_disable(might_resched); |
6971 |
++ preempt_dynamic_disable(preempt_schedule); |
6972 |
++ preempt_dynamic_disable(preempt_schedule_notrace); |
6973 |
++ preempt_dynamic_disable(irqentry_exit_cond_resched); |
6974 |
++ pr_info("Dynamic Preempt: none\n"); |
6975 |
++ break; |
6976 |
++ |
6977 |
++ case preempt_dynamic_voluntary: |
6978 |
++ preempt_dynamic_enable(cond_resched); |
6979 |
++ preempt_dynamic_enable(might_resched); |
6980 |
++ preempt_dynamic_disable(preempt_schedule); |
6981 |
++ preempt_dynamic_disable(preempt_schedule_notrace); |
6982 |
++ preempt_dynamic_disable(irqentry_exit_cond_resched); |
6983 |
++ pr_info("Dynamic Preempt: voluntary\n"); |
6984 |
++ break; |
6985 |
++ |
6986 |
++ case preempt_dynamic_full: |
6987 |
++ preempt_dynamic_disable(cond_resched); |
6988 |
++ preempt_dynamic_disable(might_resched); |
6989 |
++ preempt_dynamic_enable(preempt_schedule); |
6990 |
++ preempt_dynamic_enable(preempt_schedule_notrace); |
6991 |
++ preempt_dynamic_enable(irqentry_exit_cond_resched); |
6992 |
++ pr_info("Dynamic Preempt: full\n"); |
6993 |
++ break; |
6994 |
++ } |
6995 |
++ |
6996 |
++ preempt_dynamic_mode = mode; |
6997 |
++} |
6998 |
++ |
6999 |
++static int __init setup_preempt_mode(char *str) |
7000 |
++{ |
7001 |
++ int mode = sched_dynamic_mode(str); |
7002 |
++ if (mode < 0) { |
7003 |
++ pr_warn("Dynamic Preempt: unsupported mode: %s\n", str); |
7004 |
++ return 0; |
7005 |
++ } |
7006 |
++ |
7007 |
++ sched_dynamic_update(mode); |
7008 |
++ return 1; |
7009 |
++} |
7010 |
++__setup("preempt=", setup_preempt_mode); |
7011 |
++ |
7012 |
++static void __init preempt_dynamic_init(void) |
7013 |
++{ |
7014 |
++ if (preempt_dynamic_mode == preempt_dynamic_undefined) { |
7015 |
++ if (IS_ENABLED(CONFIG_PREEMPT_NONE)) { |
7016 |
++ sched_dynamic_update(preempt_dynamic_none); |
7017 |
++ } else if (IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY)) { |
7018 |
++ sched_dynamic_update(preempt_dynamic_voluntary); |
7019 |
++ } else { |
7020 |
++ /* Default static call setting, nothing to do */ |
7021 |
++ WARN_ON_ONCE(!IS_ENABLED(CONFIG_PREEMPT)); |
7022 |
++ preempt_dynamic_mode = preempt_dynamic_full; |
7023 |
++ pr_info("Dynamic Preempt: full\n"); |
7024 |
++ } |
7025 |
++ } |
7026 |
++} |
7027 |
++ |
7028 |
++#define PREEMPT_MODEL_ACCESSOR(mode) \ |
7029 |
++ bool preempt_model_##mode(void) \ |
7030 |
++ { \ |
7031 |
++ WARN_ON_ONCE(preempt_dynamic_mode == preempt_dynamic_undefined); \ |
7032 |
++ return preempt_dynamic_mode == preempt_dynamic_##mode; \ |
7033 |
++ } \ |
7034 |
++ EXPORT_SYMBOL_GPL(preempt_model_##mode) |
7035 |
++ |
7036 |
++PREEMPT_MODEL_ACCESSOR(none); |
7037 |
++PREEMPT_MODEL_ACCESSOR(voluntary); |
7038 |
++PREEMPT_MODEL_ACCESSOR(full); |
7039 |
++ |
7040 |
++#else /* !CONFIG_PREEMPT_DYNAMIC */ |
7041 |
++ |
7042 |
++static inline void preempt_dynamic_init(void) { } |
7043 |
++ |
7044 |
++#endif /* #ifdef CONFIG_PREEMPT_DYNAMIC */ |
7045 |
++ |
7046 |
++/** |
7047 |
++ * yield - yield the current processor to other threads. |
7048 |
++ * |
7049 |
++ * Do not ever use this function, there's a 99% chance you're doing it wrong. |
7050 |
++ * |
7051 |
++ * The scheduler is at all times free to pick the calling task as the most |
7052 |
++ * eligible task to run, if removing the yield() call from your code breaks |
7053 |
++ * it, it's already broken. |
7054 |
++ * |
7055 |
++ * Typical broken usage is: |
7056 |
++ * |
7057 |
++ * while (!event) |
7058 |
++ * yield(); |
7059 |
++ * |
7060 |
++ * where one assumes that yield() will let 'the other' process run that will |
7061 |
++ * make event true. If the current task is a SCHED_FIFO task that will never |
7062 |
++ * happen. Never use yield() as a progress guarantee!! |
7063 |
++ * |
7064 |
++ * If you want to use yield() to wait for something, use wait_event(). |
7065 |
++ * If you want to use yield() to be 'nice' for others, use cond_resched(). |
7066 |
++ * If you still want to use yield(), do not! |
7067 |
++ */ |
7068 |
++void __sched yield(void) |
7069 |
++{ |
7070 |
++ set_current_state(TASK_RUNNING); |
7071 |
++ do_sched_yield(); |
7072 |
++} |
7073 |
++EXPORT_SYMBOL(yield); |
7074 |
++ |
7075 |
++/** |
7076 |
++ * yield_to - yield the current processor to another thread in |
7077 |
++ * your thread group, or accelerate that thread toward the |
7078 |
++ * processor it's on. |
7079 |
++ * @p: target task |
7080 |
++ * @preempt: whether task preemption is allowed or not |
7081 |
++ * |
7082 |
++ * It's the caller's job to ensure that the target task struct |
7083 |
++ * can't go away on us before we can do any checks. |
7084 |
++ * |
7085 |
++ * In Alt schedule FW, yield_to is not supported. |
7086 |
++ * |
7087 |
++ * Return: |
7088 |
++ * true (>0) if we indeed boosted the target task. |
7089 |
++ * false (0) if we failed to boost the target. |
7090 |
++ * -ESRCH if there's no task to yield to. |
7091 |
++ */ |
7092 |
++int __sched yield_to(struct task_struct *p, bool preempt) |
7093 |
++{ |
7094 |
++ return 0; |
7095 |
++} |
7096 |
++EXPORT_SYMBOL_GPL(yield_to); |
7097 |
++ |
7098 |
++int io_schedule_prepare(void) |
7099 |
++{ |
7100 |
++ int old_iowait = current->in_iowait; |
7101 |
++ |
7102 |
++ current->in_iowait = 1; |
7103 |
++ blk_flush_plug(current->plug, true); |
7104 |
++ return old_iowait; |
7105 |
++} |
7106 |
++ |
7107 |
++void io_schedule_finish(int token) |
7108 |
++{ |
7109 |
++ current->in_iowait = token; |
7110 |
++} |
7111 |
++ |
7112 |
++/* |
7113 |
++ * This task is about to go to sleep on IO. Increment rq->nr_iowait so |
7114 |
++ * that process accounting knows that this is a task in IO wait state. |
7115 |
++ * |
7116 |
++ * But don't do that if it is a deliberate, throttling IO wait (this task |
7117 |
++ * has set its backing_dev_info: the queue against which it should throttle) |
7118 |
++ */ |
7119 |
++ |
7120 |
++long __sched io_schedule_timeout(long timeout) |
7121 |
++{ |
7122 |
++ int token; |
7123 |
++ long ret; |
7124 |
++ |
7125 |
++ token = io_schedule_prepare(); |
7126 |
++ ret = schedule_timeout(timeout); |
7127 |
++ io_schedule_finish(token); |
7128 |
++ |
7129 |
++ return ret; |
7130 |
++} |
7131 |
++EXPORT_SYMBOL(io_schedule_timeout); |
7132 |
++ |
7133 |
++void __sched io_schedule(void) |
7134 |
++{ |
7135 |
++ int token; |
7136 |
++ |
7137 |
++ token = io_schedule_prepare(); |
7138 |
++ schedule(); |
7139 |
++ io_schedule_finish(token); |
7140 |
++} |
7141 |
++EXPORT_SYMBOL(io_schedule); |
7142 |
++ |
7143 |
++/** |
7144 |
++ * sys_sched_get_priority_max - return maximum RT priority. |
7145 |
++ * @policy: scheduling class. |
7146 |
++ * |
7147 |
++ * Return: On success, this syscall returns the maximum |
7148 |
++ * rt_priority that can be used by a given scheduling class. |
7149 |
++ * On failure, a negative error code is returned. |
7150 |
++ */ |
7151 |
++SYSCALL_DEFINE1(sched_get_priority_max, int, policy) |
7152 |
++{ |
7153 |
++ int ret = -EINVAL; |
7154 |
++ |
7155 |
++ switch (policy) { |
7156 |
++ case SCHED_FIFO: |
7157 |
++ case SCHED_RR: |
7158 |
++ ret = MAX_RT_PRIO - 1; |
7159 |
++ break; |
7160 |
++ case SCHED_NORMAL: |
7161 |
++ case SCHED_BATCH: |
7162 |
++ case SCHED_IDLE: |
7163 |
++ ret = 0; |
7164 |
++ break; |
7165 |
++ } |
7166 |
++ return ret; |
7167 |
++} |
7168 |
++ |
7169 |
++/** |
7170 |
++ * sys_sched_get_priority_min - return minimum RT priority. |
7171 |
++ * @policy: scheduling class. |
7172 |
++ * |
7173 |
++ * Return: On success, this syscall returns the minimum |
7174 |
++ * rt_priority that can be used by a given scheduling class. |
7175 |
++ * On failure, a negative error code is returned. |
7176 |
++ */ |
7177 |
++SYSCALL_DEFINE1(sched_get_priority_min, int, policy) |
7178 |
++{ |
7179 |
++ int ret = -EINVAL; |
7180 |
++ |
7181 |
++ switch (policy) { |
7182 |
++ case SCHED_FIFO: |
7183 |
++ case SCHED_RR: |
7184 |
++ ret = 1; |
7185 |
++ break; |
7186 |
++ case SCHED_NORMAL: |
7187 |
++ case SCHED_BATCH: |
7188 |
++ case SCHED_IDLE: |
7189 |
++ ret = 0; |
7190 |
++ break; |
7191 |
++ } |
7192 |
++ return ret; |
7193 |
++} |
7194 |
++ |
7195 |
++static int sched_rr_get_interval(pid_t pid, struct timespec64 *t) |
7196 |
++{ |
7197 |
++ struct task_struct *p; |
7198 |
++ int retval; |
7199 |
++ |
7200 |
++ alt_sched_debug(); |
7201 |
++ |
7202 |
++ if (pid < 0) |
7203 |
++ return -EINVAL; |
7204 |
++ |
7205 |
++ retval = -ESRCH; |
7206 |
++ rcu_read_lock(); |
7207 |
++ p = find_process_by_pid(pid); |
7208 |
++ if (!p) |
7209 |
++ goto out_unlock; |
7210 |
++ |
7211 |
++ retval = security_task_getscheduler(p); |
7212 |
++ if (retval) |
7213 |
++ goto out_unlock; |
7214 |
++ rcu_read_unlock(); |
7215 |
++ |
7216 |
++ *t = ns_to_timespec64(sched_timeslice_ns); |
7217 |
++ return 0; |
7218 |
++ |
7219 |
++out_unlock: |
7220 |
++ rcu_read_unlock(); |
7221 |
++ return retval; |
7222 |
++} |
7223 |
++ |
7224 |
++/** |
7225 |
++ * sys_sched_rr_get_interval - return the default timeslice of a process. |
7226 |
++ * @pid: pid of the process. |
7227 |
++ * @interval: userspace pointer to the timeslice value. |
7228 |
++ * |
7229 |
++ * |
7230 |
++ * Return: On success, 0 and the timeslice is in @interval. Otherwise, |
7231 |
++ * an error code. |
7232 |
++ */ |
7233 |
++SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, |
7234 |
++ struct __kernel_timespec __user *, interval) |
7235 |
++{ |
7236 |
++ struct timespec64 t; |
7237 |
++ int retval = sched_rr_get_interval(pid, &t); |
7238 |
++ |
7239 |
++ if (retval == 0) |
7240 |
++ retval = put_timespec64(&t, interval); |
7241 |
++ |
7242 |
++ return retval; |
7243 |
++} |
7244 |
++ |
7245 |
++#ifdef CONFIG_COMPAT_32BIT_TIME |
7246 |
++SYSCALL_DEFINE2(sched_rr_get_interval_time32, pid_t, pid, |
7247 |
++ struct old_timespec32 __user *, interval) |
7248 |
++{ |
7249 |
++ struct timespec64 t; |
7250 |
++ int retval = sched_rr_get_interval(pid, &t); |
7251 |
++ |
7252 |
++ if (retval == 0) |
7253 |
++ retval = put_old_timespec32(&t, interval); |
7254 |
++ return retval; |
7255 |
++} |
7256 |
++#endif |
7257 |
++ |
7258 |
++void sched_show_task(struct task_struct *p) |
7259 |
++{ |
7260 |
++ unsigned long free = 0; |
7261 |
++ int ppid; |
7262 |
++ |
7263 |
++ if (!try_get_task_stack(p)) |
7264 |
++ return; |
7265 |
++ |
7266 |
++ pr_info("task:%-15.15s state:%c", p->comm, task_state_to_char(p)); |
7267 |
++ |
7268 |
++ if (task_is_running(p)) |
7269 |
++ pr_cont(" running task "); |
7270 |
++#ifdef CONFIG_DEBUG_STACK_USAGE |
7271 |
++ free = stack_not_used(p); |
7272 |
++#endif |
7273 |
++ ppid = 0; |
7274 |
++ rcu_read_lock(); |
7275 |
++ if (pid_alive(p)) |
7276 |
++ ppid = task_pid_nr(rcu_dereference(p->real_parent)); |
7277 |
++ rcu_read_unlock(); |
7278 |
++ pr_cont(" stack:%5lu pid:%5d ppid:%6d flags:0x%08lx\n", |
7279 |
++ free, task_pid_nr(p), ppid, |
7280 |
++ read_task_thread_flags(p)); |
7281 |
++ |
7282 |
++ print_worker_info(KERN_INFO, p); |
7283 |
++ print_stop_info(KERN_INFO, p); |
7284 |
++ show_stack(p, NULL, KERN_INFO); |
7285 |
++ put_task_stack(p); |
7286 |
++} |
7287 |
++EXPORT_SYMBOL_GPL(sched_show_task); |
7288 |
++ |
7289 |
++static inline bool |
7290 |
++state_filter_match(unsigned long state_filter, struct task_struct *p) |
7291 |
++{ |
7292 |
++ unsigned int state = READ_ONCE(p->__state); |
7293 |
++ |
7294 |
++ /* no filter, everything matches */ |
7295 |
++ if (!state_filter) |
7296 |
++ return true; |
7297 |
++ |
7298 |
++ /* filter, but doesn't match */ |
7299 |
++ if (!(state & state_filter)) |
7300 |
++ return false; |
7301 |
++ |
7302 |
++ /* |
7303 |
++ * When looking for TASK_UNINTERRUPTIBLE skip TASK_IDLE (allows |
7304 |
++ * TASK_KILLABLE). |
7305 |
++ */ |
7306 |
++ if (state_filter == TASK_UNINTERRUPTIBLE && state == TASK_IDLE) |
7307 |
++ return false; |
7308 |
++ |
7309 |
++ return true; |
7310 |
++} |
7311 |
++ |
7312 |
++ |
7313 |
++void show_state_filter(unsigned int state_filter) |
7314 |
++{ |
7315 |
++ struct task_struct *g, *p; |
7316 |
++ |
7317 |
++ rcu_read_lock(); |
7318 |
++ for_each_process_thread(g, p) { |
7319 |
++ /* |
7320 |
++ * reset the NMI-timeout, listing all files on a slow |
7321 |
++ * console might take a lot of time: |
7322 |
++ * Also, reset softlockup watchdogs on all CPUs, because |
7323 |
++ * another CPU might be blocked waiting for us to process |
7324 |
++ * an IPI. |
7325 |
++ */ |
7326 |
++ touch_nmi_watchdog(); |
7327 |
++ touch_all_softlockup_watchdogs(); |
7328 |
++ if (state_filter_match(state_filter, p)) |
7329 |
++ sched_show_task(p); |
7330 |
++ } |
7331 |
++ |
7332 |
++#ifdef CONFIG_SCHED_DEBUG |
7333 |
++ /* TODO: Alt schedule FW should support this |
7334 |
++ if (!state_filter) |
7335 |
++ sysrq_sched_debug_show(); |
7336 |
++ */ |
7337 |
++#endif |
7338 |
++ rcu_read_unlock(); |
7339 |
++ /* |
7340 |
++ * Only show locks if all tasks are dumped: |
7341 |
++ */ |
7342 |
++ if (!state_filter) |
7343 |
++ debug_show_all_locks(); |
7344 |
++} |
7345 |
++ |
7346 |
++void dump_cpu_task(int cpu) |
7347 |
++{ |
7348 |
++ pr_info("Task dump for CPU %d:\n", cpu); |
7349 |
++ sched_show_task(cpu_curr(cpu)); |
7350 |
++} |
7351 |
++ |
7352 |
++/** |
7353 |
++ * init_idle - set up an idle thread for a given CPU |
7354 |
++ * @idle: task in question |
7355 |
++ * @cpu: CPU the idle task belongs to |
7356 |
++ * |
7357 |
++ * NOTE: this function does not set the idle thread's NEED_RESCHED |
7358 |
++ * flag, to make booting more robust. |
7359 |
++ */ |
7360 |
++void __init init_idle(struct task_struct *idle, int cpu) |
7361 |
++{ |
7362 |
++ struct rq *rq = cpu_rq(cpu); |
7363 |
++ unsigned long flags; |
7364 |
++ |
7365 |
++ __sched_fork(0, idle); |
7366 |
++ |
7367 |
++ raw_spin_lock_irqsave(&idle->pi_lock, flags); |
7368 |
++ raw_spin_lock(&rq->lock); |
7369 |
++ update_rq_clock(rq); |
7370 |
++ |
7371 |
++ idle->last_ran = rq->clock_task; |
7372 |
++ idle->__state = TASK_RUNNING; |
7373 |
++ /* |
7374 |
++ * PF_KTHREAD should already be set at this point; regardless, make it |
7375 |
++ * look like a proper per-CPU kthread. |
7376 |
++ */ |
7377 |
++ idle->flags |= PF_IDLE | PF_KTHREAD | PF_NO_SETAFFINITY; |
7378 |
++ kthread_set_per_cpu(idle, cpu); |
7379 |
++ |
7380 |
++ sched_queue_init_idle(&rq->queue, idle); |
7381 |
++ |
7382 |
++#ifdef CONFIG_SMP |
7383 |
++ /* |
7384 |
++ * It's possible that init_idle() gets called multiple times on a task, |
7385 |
++ * in that case do_set_cpus_allowed() will not do the right thing. |
7386 |
++ * |
7387 |
++ * And since this is boot we can forgo the serialisation. |
7388 |
++ */ |
7389 |
++ set_cpus_allowed_common(idle, cpumask_of(cpu)); |
7390 |
++#endif |
7391 |
++ |
7392 |
++ /* Silence PROVE_RCU */ |
7393 |
++ rcu_read_lock(); |
7394 |
++ __set_task_cpu(idle, cpu); |
7395 |
++ rcu_read_unlock(); |
7396 |
++ |
7397 |
++ rq->idle = idle; |
7398 |
++ rcu_assign_pointer(rq->curr, idle); |
7399 |
++ idle->on_cpu = 1; |
7400 |
++ |
7401 |
++ raw_spin_unlock(&rq->lock); |
7402 |
++ raw_spin_unlock_irqrestore(&idle->pi_lock, flags); |
7403 |
++ |
7404 |
++ /* Set the preempt count _outside_ the spinlocks! */ |
7405 |
++ init_idle_preempt_count(idle, cpu); |
7406 |
++ |
7407 |
++ ftrace_graph_init_idle_task(idle, cpu); |
7408 |
++ vtime_init_idle(idle, cpu); |
7409 |
++#ifdef CONFIG_SMP |
7410 |
++ sprintf(idle->comm, "%s/%d", INIT_TASK_COMM, cpu); |
7411 |
++#endif |
7412 |
++} |
7413 |
++ |
7414 |
++#ifdef CONFIG_SMP |
7415 |
++ |
7416 |
++int cpuset_cpumask_can_shrink(const struct cpumask __maybe_unused *cur, |
7417 |
++ const struct cpumask __maybe_unused *trial) |
7418 |
++{ |
7419 |
++ return 1; |
7420 |
++} |
7421 |
++ |
7422 |
++int task_can_attach(struct task_struct *p, |
7423 |
++ const struct cpumask *cs_cpus_allowed) |
7424 |
++{ |
7425 |
++ int ret = 0; |
7426 |
++ |
7427 |
++ /* |
7428 |
++ * Kthreads which disallow setaffinity shouldn't be moved |
7429 |
++ * to a new cpuset; we don't want to change their CPU |
7430 |
++ * affinity and isolating such threads by their set of |
7431 |
++ * allowed nodes is unnecessary. Thus, cpusets are not |
7432 |
++ * applicable for such threads. This prevents checking for |
7433 |
++ * success of set_cpus_allowed_ptr() on all attached tasks |
7434 |
++ * before cpus_mask may be changed. |
7435 |
++ */ |
7436 |
++ if (p->flags & PF_NO_SETAFFINITY) |
7437 |
++ ret = -EINVAL; |
7438 |
++ |
7439 |
++ return ret; |
7440 |
++} |
7441 |
++ |
7442 |
++bool sched_smp_initialized __read_mostly; |
7443 |
++ |
7444 |
++#ifdef CONFIG_HOTPLUG_CPU |
7445 |
++/* |
7446 |
++ * Ensures that the idle task is using init_mm right before its CPU goes |
7447 |
++ * offline. |
7448 |
++ */ |
7449 |
++void idle_task_exit(void) |
7450 |
++{ |
7451 |
++ struct mm_struct *mm = current->active_mm; |
7452 |
++ |
7453 |
++ BUG_ON(current != this_rq()->idle); |
7454 |
++ |
7455 |
++ if (mm != &init_mm) { |
7456 |
++ switch_mm(mm, &init_mm, current); |
7457 |
++ finish_arch_post_lock_switch(); |
7458 |
++ } |
7459 |
++ |
7460 |
++ /* finish_cpu(), as ran on the BP, will clean up the active_mm state */ |
7461 |
++} |
7462 |
++ |
7463 |
++static int __balance_push_cpu_stop(void *arg) |
7464 |
++{ |
7465 |
++ struct task_struct *p = arg; |
7466 |
++ struct rq *rq = this_rq(); |
7467 |
++ struct rq_flags rf; |
7468 |
++ int cpu; |
7469 |
++ |
7470 |
++ raw_spin_lock_irq(&p->pi_lock); |
7471 |
++ rq_lock(rq, &rf); |
7472 |
++ |
7473 |
++ update_rq_clock(rq); |
7474 |
++ |
7475 |
++ if (task_rq(p) == rq && task_on_rq_queued(p)) { |
7476 |
++ cpu = select_fallback_rq(rq->cpu, p); |
7477 |
++ rq = __migrate_task(rq, p, cpu); |
7478 |
++ } |
7479 |
++ |
7480 |
++ rq_unlock(rq, &rf); |
7481 |
++ raw_spin_unlock_irq(&p->pi_lock); |
7482 |
++ |
7483 |
++ put_task_struct(p); |
7484 |
++ |
7485 |
++ return 0; |
7486 |
++} |
7487 |
++ |
7488 |
++static DEFINE_PER_CPU(struct cpu_stop_work, push_work); |
7489 |
++ |
7490 |
++/* |
7491 |
++ * This is enabled below SCHED_AP_ACTIVE; when !cpu_active(), but only |
7492 |
++ * effective when the hotplug motion is down. |
7493 |
++ */ |
7494 |
++static void balance_push(struct rq *rq) |
7495 |
++{ |
7496 |
++ struct task_struct *push_task = rq->curr; |
7497 |
++ |
7498 |
++ lockdep_assert_held(&rq->lock); |
7499 |
++ |
7500 |
++ /* |
7501 |
++ * Ensure the thing is persistent until balance_push_set(.on = false); |
7502 |
++ */ |
7503 |
++ rq->balance_callback = &balance_push_callback; |
7504 |
++ |
7505 |
++ /* |
7506 |
++ * Only active while going offline and when invoked on the outgoing |
7507 |
++ * CPU. |
7508 |
++ */ |
7509 |
++ if (!cpu_dying(rq->cpu) || rq != this_rq()) |
7510 |
++ return; |
7511 |
++ |
7512 |
++ /* |
7513 |
++ * Both the cpu-hotplug and stop task are in this case and are |
7514 |
++ * required to complete the hotplug process. |
7515 |
++ */ |
7516 |
++ if (kthread_is_per_cpu(push_task) || |
7517 |
++ is_migration_disabled(push_task)) { |
7518 |
++ |
7519 |
++ /* |
7520 |
++ * If this is the idle task on the outgoing CPU try to wake |
7521 |
++ * up the hotplug control thread which might wait for the |
7522 |
++ * last task to vanish. The rcuwait_active() check is |
7523 |
++ * accurate here because the waiter is pinned on this CPU |
7524 |
++ * and can't obviously be running in parallel. |
7525 |
++ * |
7526 |
++ * On RT kernels this also has to check whether there are |
7527 |
++ * pinned and scheduled out tasks on the runqueue. They |
7528 |
++ * need to leave the migrate disabled section first. |
7529 |
++ */ |
7530 |
++ if (!rq->nr_running && !rq_has_pinned_tasks(rq) && |
7531 |
++ rcuwait_active(&rq->hotplug_wait)) { |
7532 |
++ raw_spin_unlock(&rq->lock); |
7533 |
++ rcuwait_wake_up(&rq->hotplug_wait); |
7534 |
++ raw_spin_lock(&rq->lock); |
7535 |
++ } |
7536 |
++ return; |
7537 |
++ } |
7538 |
++ |
7539 |
++ get_task_struct(push_task); |
7540 |
++ /* |
7541 |
++ * Temporarily drop rq->lock such that we can wake-up the stop task. |
7542 |
++ * Both preemption and IRQs are still disabled. |
7543 |
++ */ |
7544 |
++ raw_spin_unlock(&rq->lock); |
7545 |
++ stop_one_cpu_nowait(rq->cpu, __balance_push_cpu_stop, push_task, |
7546 |
++ this_cpu_ptr(&push_work)); |
7547 |
++ /* |
7548 |
++ * At this point need_resched() is true and we'll take the loop in |
7549 |
++ * schedule(). The next pick is obviously going to be the stop task |
7550 |
++ * which kthread_is_per_cpu() and will push this task away. |
7551 |
++ */ |
7552 |
++ raw_spin_lock(&rq->lock); |
7553 |
++} |
7554 |
++ |
7555 |
++static void balance_push_set(int cpu, bool on) |
7556 |
++{ |
7557 |
++ struct rq *rq = cpu_rq(cpu); |
7558 |
++ struct rq_flags rf; |
7559 |
++ |
7560 |
++ rq_lock_irqsave(rq, &rf); |
7561 |
++ if (on) { |
7562 |
++ WARN_ON_ONCE(rq->balance_callback); |
7563 |
++ rq->balance_callback = &balance_push_callback; |
7564 |
++ } else if (rq->balance_callback == &balance_push_callback) { |
7565 |
++ rq->balance_callback = NULL; |
7566 |
++ } |
7567 |
++ rq_unlock_irqrestore(rq, &rf); |
7568 |
++} |
7569 |
++ |
7570 |
++/* |
7571 |
++ * Invoked from a CPUs hotplug control thread after the CPU has been marked |
7572 |
++ * inactive. All tasks which are not per CPU kernel threads are either |
7573 |
++ * pushed off this CPU now via balance_push() or placed on a different CPU |
7574 |
++ * during wakeup. Wait until the CPU is quiescent. |
7575 |
++ */ |
7576 |
++static void balance_hotplug_wait(void) |
7577 |
++{ |
7578 |
++ struct rq *rq = this_rq(); |
7579 |
++ |
7580 |
++ rcuwait_wait_event(&rq->hotplug_wait, |
7581 |
++ rq->nr_running == 1 && !rq_has_pinned_tasks(rq), |
7582 |
++ TASK_UNINTERRUPTIBLE); |
7583 |
++} |
7584 |
++ |
7585 |
++#else |
7586 |
++ |
7587 |
++static void balance_push(struct rq *rq) |
7588 |
++{ |
7589 |
++} |
7590 |
++ |
7591 |
++static void balance_push_set(int cpu, bool on) |
7592 |
++{ |
7593 |
++} |
7594 |
++ |
7595 |
++static inline void balance_hotplug_wait(void) |
7596 |
++{ |
7597 |
++} |
7598 |
++#endif /* CONFIG_HOTPLUG_CPU */ |
7599 |
++ |
7600 |
++static void set_rq_offline(struct rq *rq) |
7601 |
++{ |
7602 |
++ if (rq->online) |
7603 |
++ rq->online = false; |
7604 |
++} |
7605 |
++ |
7606 |
++static void set_rq_online(struct rq *rq) |
7607 |
++{ |
7608 |
++ if (!rq->online) |
7609 |
++ rq->online = true; |
7610 |
++} |
7611 |
++ |
7612 |
++/* |
7613 |
++ * used to mark begin/end of suspend/resume: |
7614 |
++ */ |
7615 |
++static int num_cpus_frozen; |
7616 |
++ |
7617 |
++/* |
7618 |
++ * Update cpusets according to cpu_active mask. If cpusets are |
7619 |
++ * disabled, cpuset_update_active_cpus() becomes a simple wrapper |
7620 |
++ * around partition_sched_domains(). |
7621 |
++ * |
7622 |
++ * If we come here as part of a suspend/resume, don't touch cpusets because we |
7623 |
++ * want to restore it back to its original state upon resume anyway. |
7624 |
++ */ |
7625 |
++static void cpuset_cpu_active(void) |
7626 |
++{ |
7627 |
++ if (cpuhp_tasks_frozen) { |
7628 |
++ /* |
7629 |
++ * num_cpus_frozen tracks how many CPUs are involved in suspend |
7630 |
++ * resume sequence. As long as this is not the last online |
7631 |
++ * operation in the resume sequence, just build a single sched |
7632 |
++ * domain, ignoring cpusets. |
7633 |
++ */ |
7634 |
++ partition_sched_domains(1, NULL, NULL); |
7635 |
++ if (--num_cpus_frozen) |
7636 |
++ return; |
7637 |
++ /* |
7638 |
++ * This is the last CPU online operation. So fall through and |
7639 |
++ * restore the original sched domains by considering the |
7640 |
++ * cpuset configurations. |
7641 |
++ */ |
7642 |
++ cpuset_force_rebuild(); |
7643 |
++ } |
7644 |
++ |
7645 |
++ cpuset_update_active_cpus(); |
7646 |
++} |
7647 |
++ |
7648 |
++static int cpuset_cpu_inactive(unsigned int cpu) |
7649 |
++{ |
7650 |
++ if (!cpuhp_tasks_frozen) { |
7651 |
++ cpuset_update_active_cpus(); |
7652 |
++ } else { |
7653 |
++ num_cpus_frozen++; |
7654 |
++ partition_sched_domains(1, NULL, NULL); |
7655 |
++ } |
7656 |
++ return 0; |
7657 |
++} |
7658 |
++ |
7659 |
++int sched_cpu_activate(unsigned int cpu) |
7660 |
++{ |
7661 |
++ struct rq *rq = cpu_rq(cpu); |
7662 |
++ unsigned long flags; |
7663 |
++ |
7664 |
++ /* |
7665 |
++ * Clear the balance_push callback and prepare to schedule |
7666 |
++ * regular tasks. |
7667 |
++ */ |
7668 |
++ balance_push_set(cpu, false); |
7669 |
++ |
7670 |
++#ifdef CONFIG_SCHED_SMT |
7671 |
++ /* |
7672 |
++ * When going up, increment the number of cores with SMT present. |
7673 |
++ */ |
7674 |
++ if (cpumask_weight(cpu_smt_mask(cpu)) == 2) |
7675 |
++ static_branch_inc_cpuslocked(&sched_smt_present); |
7676 |
++#endif |
7677 |
++ set_cpu_active(cpu, true); |
7678 |
++ |
7679 |
++ if (sched_smp_initialized) |
7680 |
++ cpuset_cpu_active(); |
7681 |
++ |
7682 |
++ /* |
7683 |
++ * Put the rq online, if not already. This happens: |
7684 |
++ * |
7685 |
++ * 1) In the early boot process, because we build the real domains |
7686 |
++ * after all cpus have been brought up. |
7687 |
++ * |
7688 |
++ * 2) At runtime, if cpuset_cpu_active() fails to rebuild the |
7689 |
++ * domains. |
7690 |
++ */ |
7691 |
++ raw_spin_lock_irqsave(&rq->lock, flags); |
7692 |
++ set_rq_online(rq); |
7693 |
++ raw_spin_unlock_irqrestore(&rq->lock, flags); |
7694 |
++ |
7695 |
++ return 0; |
7696 |
++} |
7697 |
++ |
7698 |
++int sched_cpu_deactivate(unsigned int cpu) |
7699 |
++{ |
7700 |
++ struct rq *rq = cpu_rq(cpu); |
7701 |
++ unsigned long flags; |
7702 |
++ int ret; |
7703 |
++ |
7704 |
++ set_cpu_active(cpu, false); |
7705 |
++ |
7706 |
++ /* |
7707 |
++ * From this point forward, this CPU will refuse to run any task that |
7708 |
++ * is not: migrate_disable() or KTHREAD_IS_PER_CPU, and will actively |
7709 |
++ * push those tasks away until this gets cleared, see |
7710 |
++ * sched_cpu_dying(). |
7711 |
++ */ |
7712 |
++ balance_push_set(cpu, true); |
7713 |
++ |
7714 |
++ /* |
7715 |
++ * We've cleared cpu_active_mask, wait for all preempt-disabled and RCU |
7716 |
++ * users of this state to go away such that all new such users will |
7717 |
++ * observe it. |
7718 |
++ * |
7719 |
++ * Specifically, we rely on ttwu to no longer target this CPU, see |
7720 |
++ * ttwu_queue_cond() and is_cpu_allowed(). |
7721 |
++ * |
7722 |
++ * Do sync before park smpboot threads to take care the rcu boost case. |
7723 |
++ */ |
7724 |
++ synchronize_rcu(); |
7725 |
++ |
7726 |
++ raw_spin_lock_irqsave(&rq->lock, flags); |
7727 |
++ update_rq_clock(rq); |
7728 |
++ set_rq_offline(rq); |
7729 |
++ raw_spin_unlock_irqrestore(&rq->lock, flags); |
7730 |
++ |
7731 |
++#ifdef CONFIG_SCHED_SMT |
7732 |
++ /* |
7733 |
++ * When going down, decrement the number of cores with SMT present. |
7734 |
++ */ |
7735 |
++ if (cpumask_weight(cpu_smt_mask(cpu)) == 2) { |
7736 |
++ static_branch_dec_cpuslocked(&sched_smt_present); |
7737 |
++ if (!static_branch_likely(&sched_smt_present)) |
7738 |
++ cpumask_clear(&sched_sg_idle_mask); |
7739 |
++ } |
7740 |
++#endif |
7741 |
++ |
7742 |
++ if (!sched_smp_initialized) |
7743 |
++ return 0; |
7744 |
++ |
7745 |
++ ret = cpuset_cpu_inactive(cpu); |
7746 |
++ if (ret) { |
7747 |
++ balance_push_set(cpu, false); |
7748 |
++ set_cpu_active(cpu, true); |
7749 |
++ return ret; |
7750 |
++ } |
7751 |
++ |
7752 |
++ return 0; |
7753 |
++} |
7754 |
++ |
7755 |
++static void sched_rq_cpu_starting(unsigned int cpu) |
7756 |
++{ |
7757 |
++ struct rq *rq = cpu_rq(cpu); |
7758 |
++ |
7759 |
++ rq->calc_load_update = calc_load_update; |
7760 |
++} |
7761 |
++ |
7762 |
++int sched_cpu_starting(unsigned int cpu) |
7763 |
++{ |
7764 |
++ sched_rq_cpu_starting(cpu); |
7765 |
++ sched_tick_start(cpu); |
7766 |
++ return 0; |
7767 |
++} |
7768 |
++ |
7769 |
++#ifdef CONFIG_HOTPLUG_CPU |
7770 |
++ |
7771 |
++/* |
7772 |
++ * Invoked immediately before the stopper thread is invoked to bring the |
7773 |
++ * CPU down completely. At this point all per CPU kthreads except the |
7774 |
++ * hotplug thread (current) and the stopper thread (inactive) have been |
7775 |
++ * either parked or have been unbound from the outgoing CPU. Ensure that |
7776 |
++ * any of those which might be on the way out are gone. |
7777 |
++ * |
7778 |
++ * If after this point a bound task is being woken on this CPU then the |
7779 |
++ * responsible hotplug callback has failed to do it's job. |
7780 |
++ * sched_cpu_dying() will catch it with the appropriate fireworks. |
7781 |
++ */ |
7782 |
++int sched_cpu_wait_empty(unsigned int cpu) |
7783 |
++{ |
7784 |
++ balance_hotplug_wait(); |
7785 |
++ return 0; |
7786 |
++} |
7787 |
++ |
7788 |
++/* |
7789 |
++ * Since this CPU is going 'away' for a while, fold any nr_active delta we |
7790 |
++ * might have. Called from the CPU stopper task after ensuring that the |
7791 |
++ * stopper is the last running task on the CPU, so nr_active count is |
7792 |
++ * stable. We need to take the teardown thread which is calling this into |
7793 |
++ * account, so we hand in adjust = 1 to the load calculation. |
7794 |
++ * |
7795 |
++ * Also see the comment "Global load-average calculations". |
7796 |
++ */ |
7797 |
++static void calc_load_migrate(struct rq *rq) |
7798 |
++{ |
7799 |
++ long delta = calc_load_fold_active(rq, 1); |
7800 |
++ |
7801 |
++ if (delta) |
7802 |
++ atomic_long_add(delta, &calc_load_tasks); |
7803 |
++} |
7804 |
++ |
7805 |
++static void dump_rq_tasks(struct rq *rq, const char *loglvl) |
7806 |
++{ |
7807 |
++ struct task_struct *g, *p; |
7808 |
++ int cpu = cpu_of(rq); |
7809 |
++ |
7810 |
++ lockdep_assert_held(&rq->lock); |
7811 |
++ |
7812 |
++ printk("%sCPU%d enqueued tasks (%u total):\n", loglvl, cpu, rq->nr_running); |
7813 |
++ for_each_process_thread(g, p) { |
7814 |
++ if (task_cpu(p) != cpu) |
7815 |
++ continue; |
7816 |
++ |
7817 |
++ if (!task_on_rq_queued(p)) |
7818 |
++ continue; |
7819 |
++ |
7820 |
++ printk("%s\tpid: %d, name: %s\n", loglvl, p->pid, p->comm); |
7821 |
++ } |
7822 |
++} |
7823 |
++ |
7824 |
++int sched_cpu_dying(unsigned int cpu) |
7825 |
++{ |
7826 |
++ struct rq *rq = cpu_rq(cpu); |
7827 |
++ unsigned long flags; |
7828 |
++ |
7829 |
++ /* Handle pending wakeups and then migrate everything off */ |
7830 |
++ sched_tick_stop(cpu); |
7831 |
++ |
7832 |
++ raw_spin_lock_irqsave(&rq->lock, flags); |
7833 |
++ if (rq->nr_running != 1 || rq_has_pinned_tasks(rq)) { |
7834 |
++ WARN(true, "Dying CPU not properly vacated!"); |
7835 |
++ dump_rq_tasks(rq, KERN_WARNING); |
7836 |
++ } |
7837 |
++ raw_spin_unlock_irqrestore(&rq->lock, flags); |
7838 |
++ |
7839 |
++ calc_load_migrate(rq); |
7840 |
++ hrtick_clear(rq); |
7841 |
++ return 0; |
7842 |
++} |
7843 |
++#endif |
7844 |
++ |
7845 |
++#ifdef CONFIG_SMP |
7846 |
++static void sched_init_topology_cpumask_early(void) |
7847 |
++{ |
7848 |
++ int cpu; |
7849 |
++ cpumask_t *tmp; |
7850 |
++ |
7851 |
++ for_each_possible_cpu(cpu) { |
7852 |
++ /* init topo masks */ |
7853 |
++ tmp = per_cpu(sched_cpu_topo_masks, cpu); |
7854 |
++ |
7855 |
++ cpumask_copy(tmp, cpumask_of(cpu)); |
7856 |
++ tmp++; |
7857 |
++ cpumask_copy(tmp, cpu_possible_mask); |
7858 |
++ per_cpu(sched_cpu_llc_mask, cpu) = tmp; |
7859 |
++ per_cpu(sched_cpu_topo_end_mask, cpu) = ++tmp; |
7860 |
++ /*per_cpu(sd_llc_id, cpu) = cpu;*/ |
7861 |
++ } |
7862 |
++} |
7863 |
++ |
7864 |
++#define TOPOLOGY_CPUMASK(name, mask, last)\ |
7865 |
++ if (cpumask_and(topo, topo, mask)) { \ |
7866 |
++ cpumask_copy(topo, mask); \ |
7867 |
++ printk(KERN_INFO "sched: cpu#%02d topo: 0x%08lx - "#name, \ |
7868 |
++ cpu, (topo++)->bits[0]); \ |
7869 |
++ } \ |
7870 |
++ if (!last) \ |
7871 |
++ cpumask_complement(topo, mask) |
7872 |
++ |
7873 |
++static void sched_init_topology_cpumask(void) |
7874 |
++{ |
7875 |
++ int cpu; |
7876 |
++ cpumask_t *topo; |
7877 |
++ |
7878 |
++ for_each_online_cpu(cpu) { |
7879 |
++ /* take chance to reset time slice for idle tasks */ |
7880 |
++ cpu_rq(cpu)->idle->time_slice = sched_timeslice_ns; |
7881 |
++ |
7882 |
++ topo = per_cpu(sched_cpu_topo_masks, cpu) + 1; |
7883 |
++ |
7884 |
++ cpumask_complement(topo, cpumask_of(cpu)); |
7885 |
++#ifdef CONFIG_SCHED_SMT |
7886 |
++ TOPOLOGY_CPUMASK(smt, topology_sibling_cpumask(cpu), false); |
7887 |
++#endif |
7888 |
++ per_cpu(sd_llc_id, cpu) = cpumask_first(cpu_coregroup_mask(cpu)); |
7889 |
++ per_cpu(sched_cpu_llc_mask, cpu) = topo; |
7890 |
++ TOPOLOGY_CPUMASK(coregroup, cpu_coregroup_mask(cpu), false); |
7891 |
++ |
7892 |
++ TOPOLOGY_CPUMASK(core, topology_core_cpumask(cpu), false); |
7893 |
++ |
7894 |
++ TOPOLOGY_CPUMASK(others, cpu_online_mask, true); |
7895 |
++ |
7896 |
++ per_cpu(sched_cpu_topo_end_mask, cpu) = topo; |
7897 |
++ printk(KERN_INFO "sched: cpu#%02d llc_id = %d, llc_mask idx = %d\n", |
7898 |
++ cpu, per_cpu(sd_llc_id, cpu), |
7899 |
++ (int) (per_cpu(sched_cpu_llc_mask, cpu) - |
7900 |
++ per_cpu(sched_cpu_topo_masks, cpu))); |
7901 |
++ } |
7902 |
++} |
7903 |
++#endif |
7904 |
++ |
7905 |
++void __init sched_init_smp(void) |
7906 |
++{ |
7907 |
++ /* Move init over to a non-isolated CPU */ |
7908 |
++ if (set_cpus_allowed_ptr(current, housekeeping_cpumask(HK_TYPE_DOMAIN)) < 0) |
7909 |
++ BUG(); |
7910 |
++ current->flags &= ~PF_NO_SETAFFINITY; |
7911 |
++ |
7912 |
++ sched_init_topology_cpumask(); |
7913 |
++ |
7914 |
++ sched_smp_initialized = true; |
7915 |
++} |
7916 |
++#else |
7917 |
++void __init sched_init_smp(void) |
7918 |
++{ |
7919 |
++ cpu_rq(0)->idle->time_slice = sched_timeslice_ns; |
7920 |
++} |
7921 |
++#endif /* CONFIG_SMP */ |
7922 |
++ |
7923 |
++int in_sched_functions(unsigned long addr) |
7924 |
++{ |
7925 |
++ return in_lock_functions(addr) || |
7926 |
++ (addr >= (unsigned long)__sched_text_start |
7927 |
++ && addr < (unsigned long)__sched_text_end); |
7928 |
++} |
7929 |
++ |
7930 |
++#ifdef CONFIG_CGROUP_SCHED |
7931 |
++/* task group related information */ |
7932 |
++struct task_group { |
7933 |
++ struct cgroup_subsys_state css; |
7934 |
++ |
7935 |
++ struct rcu_head rcu; |
7936 |
++ struct list_head list; |
7937 |
++ |
7938 |
++ struct task_group *parent; |
7939 |
++ struct list_head siblings; |
7940 |
++ struct list_head children; |
7941 |
++#ifdef CONFIG_FAIR_GROUP_SCHED |
7942 |
++ unsigned long shares; |
7943 |
++#endif |
7944 |
++}; |
7945 |
++ |
7946 |
++/* |
7947 |
++ * Default task group. |
7948 |
++ * Every task in system belongs to this group at bootup. |
7949 |
++ */ |
7950 |
++struct task_group root_task_group; |
7951 |
++LIST_HEAD(task_groups); |
7952 |
++ |
7953 |
++/* Cacheline aligned slab cache for task_group */ |
7954 |
++static struct kmem_cache *task_group_cache __read_mostly; |
7955 |
++#endif /* CONFIG_CGROUP_SCHED */ |
7956 |
++ |
7957 |
++void __init sched_init(void) |
7958 |
++{ |
7959 |
++ int i; |
7960 |
++ struct rq *rq; |
7961 |
++ |
7962 |
++ printk(KERN_INFO ALT_SCHED_VERSION_MSG); |
7963 |
++ |
7964 |
++ wait_bit_init(); |
7965 |
++ |
7966 |
++#ifdef CONFIG_SMP |
7967 |
++ for (i = 0; i < SCHED_QUEUE_BITS; i++) |
7968 |
++ cpumask_copy(sched_rq_watermark + i, cpu_present_mask); |
7969 |
++#endif |
7970 |
++ |
7971 |
++#ifdef CONFIG_CGROUP_SCHED |
7972 |
++ task_group_cache = KMEM_CACHE(task_group, 0); |
7973 |
++ |
7974 |
++ list_add(&root_task_group.list, &task_groups); |
7975 |
++ INIT_LIST_HEAD(&root_task_group.children); |
7976 |
++ INIT_LIST_HEAD(&root_task_group.siblings); |
7977 |
++#endif /* CONFIG_CGROUP_SCHED */ |
7978 |
++ for_each_possible_cpu(i) { |
7979 |
++ rq = cpu_rq(i); |
7980 |
++ |
7981 |
++ sched_queue_init(&rq->queue); |
7982 |
++ rq->watermark = IDLE_TASK_SCHED_PRIO; |
7983 |
++ rq->skip = NULL; |
7984 |
++ |
7985 |
++ raw_spin_lock_init(&rq->lock); |
7986 |
++ rq->nr_running = rq->nr_uninterruptible = 0; |
7987 |
++ rq->calc_load_active = 0; |
7988 |
++ rq->calc_load_update = jiffies + LOAD_FREQ; |
7989 |
++#ifdef CONFIG_SMP |
7990 |
++ rq->online = false; |
7991 |
++ rq->cpu = i; |
7992 |
++ |
7993 |
++#ifdef CONFIG_SCHED_SMT |
7994 |
++ rq->active_balance = 0; |
7995 |
++#endif |
7996 |
++ |
7997 |
++#ifdef CONFIG_NO_HZ_COMMON |
7998 |
++ INIT_CSD(&rq->nohz_csd, nohz_csd_func, rq); |
7999 |
++#endif |
8000 |
++ rq->balance_callback = &balance_push_callback; |
8001 |
++#ifdef CONFIG_HOTPLUG_CPU |
8002 |
++ rcuwait_init(&rq->hotplug_wait); |
8003 |
++#endif |
8004 |
++#endif /* CONFIG_SMP */ |
8005 |
++ rq->nr_switches = 0; |
8006 |
++ |
8007 |
++ hrtick_rq_init(rq); |
8008 |
++ atomic_set(&rq->nr_iowait, 0); |
8009 |
++ } |
8010 |
++#ifdef CONFIG_SMP |
8011 |
++ /* Set rq->online for cpu 0 */ |
8012 |
++ cpu_rq(0)->online = true; |
8013 |
++#endif |
8014 |
++ /* |
8015 |
++ * The boot idle thread does lazy MMU switching as well: |
8016 |
++ */ |
8017 |
++ mmgrab(&init_mm); |
8018 |
++ enter_lazy_tlb(&init_mm, current); |
8019 |
++ |
8020 |
++ /* |
8021 |
++ * The idle task doesn't need the kthread struct to function, but it |
8022 |
++ * is dressed up as a per-CPU kthread and thus needs to play the part |
8023 |
++ * if we want to avoid special-casing it in code that deals with per-CPU |
8024 |
++ * kthreads. |
8025 |
++ */ |
8026 |
++ WARN_ON(!set_kthread_struct(current)); |
8027 |
++ |
8028 |
++ /* |
8029 |
++ * Make us the idle thread. Technically, schedule() should not be |
8030 |
++ * called from this thread, however somewhere below it might be, |
8031 |
++ * but because we are the idle thread, we just pick up running again |
8032 |
++ * when this runqueue becomes "idle". |
8033 |
++ */ |
8034 |
++ init_idle(current, smp_processor_id()); |
8035 |
++ |
8036 |
++ calc_load_update = jiffies + LOAD_FREQ; |
8037 |
++ |
8038 |
++#ifdef CONFIG_SMP |
8039 |
++ idle_thread_set_boot_cpu(); |
8040 |
++ balance_push_set(smp_processor_id(), false); |
8041 |
++ |
8042 |
++ sched_init_topology_cpumask_early(); |
8043 |
++#endif /* SMP */ |
8044 |
++ |
8045 |
++ psi_init(); |
8046 |
++ |
8047 |
++ preempt_dynamic_init(); |
8048 |
++} |
8049 |
++ |
8050 |
++#ifdef CONFIG_DEBUG_ATOMIC_SLEEP |
8051 |
++ |
8052 |
++void __might_sleep(const char *file, int line) |
8053 |
++{ |
8054 |
++ unsigned int state = get_current_state(); |
8055 |
++ /* |
8056 |
++ * Blocking primitives will set (and therefore destroy) current->state, |
8057 |
++ * since we will exit with TASK_RUNNING make sure we enter with it, |
8058 |
++ * otherwise we will destroy state. |
8059 |
++ */ |
8060 |
++ WARN_ONCE(state != TASK_RUNNING && current->task_state_change, |
8061 |
++ "do not call blocking ops when !TASK_RUNNING; " |
8062 |
++ "state=%x set at [<%p>] %pS\n", state, |
8063 |
++ (void *)current->task_state_change, |
8064 |
++ (void *)current->task_state_change); |
8065 |
++ |
8066 |
++ __might_resched(file, line, 0); |
8067 |
++} |
8068 |
++EXPORT_SYMBOL(__might_sleep); |
8069 |
++ |
8070 |
++static void print_preempt_disable_ip(int preempt_offset, unsigned long ip) |
8071 |
++{ |
8072 |
++ if (!IS_ENABLED(CONFIG_DEBUG_PREEMPT)) |
8073 |
++ return; |
8074 |
++ |
8075 |
++ if (preempt_count() == preempt_offset) |
8076 |
++ return; |
8077 |
++ |
8078 |
++ pr_err("Preemption disabled at:"); |
8079 |
++ print_ip_sym(KERN_ERR, ip); |
8080 |
++} |
8081 |
++ |
8082 |
++static inline bool resched_offsets_ok(unsigned int offsets) |
8083 |
++{ |
8084 |
++ unsigned int nested = preempt_count(); |
8085 |
++ |
8086 |
++ nested += rcu_preempt_depth() << MIGHT_RESCHED_RCU_SHIFT; |
8087 |
++ |
8088 |
++ return nested == offsets; |
8089 |
++} |
8090 |
++ |
8091 |
++void __might_resched(const char *file, int line, unsigned int offsets) |
8092 |
++{ |
8093 |
++ /* Ratelimiting timestamp: */ |
8094 |
++ static unsigned long prev_jiffy; |
8095 |
++ |
8096 |
++ unsigned long preempt_disable_ip; |
8097 |
++ |
8098 |
++ /* WARN_ON_ONCE() by default, no rate limit required: */ |
8099 |
++ rcu_sleep_check(); |
8100 |
++ |
8101 |
++ if ((resched_offsets_ok(offsets) && !irqs_disabled() && |
8102 |
++ !is_idle_task(current) && !current->non_block_count) || |
8103 |
++ system_state == SYSTEM_BOOTING || system_state > SYSTEM_RUNNING || |
8104 |
++ oops_in_progress) |
8105 |
++ return; |
8106 |
++ if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) |
8107 |
++ return; |
8108 |
++ prev_jiffy = jiffies; |
8109 |
++ |
8110 |
++ /* Save this before calling printk(), since that will clobber it: */ |
8111 |
++ preempt_disable_ip = get_preempt_disable_ip(current); |
8112 |
++ |
8113 |
++ pr_err("BUG: sleeping function called from invalid context at %s:%d\n", |
8114 |
++ file, line); |
8115 |
++ pr_err("in_atomic(): %d, irqs_disabled(): %d, non_block: %d, pid: %d, name: %s\n", |
8116 |
++ in_atomic(), irqs_disabled(), current->non_block_count, |
8117 |
++ current->pid, current->comm); |
8118 |
++ pr_err("preempt_count: %x, expected: %x\n", preempt_count(), |
8119 |
++ offsets & MIGHT_RESCHED_PREEMPT_MASK); |
8120 |
++ |
8121 |
++ if (IS_ENABLED(CONFIG_PREEMPT_RCU)) { |
8122 |
++ pr_err("RCU nest depth: %d, expected: %u\n", |
8123 |
++ rcu_preempt_depth(), offsets >> MIGHT_RESCHED_RCU_SHIFT); |
8124 |
++ } |
8125 |
++ |
8126 |
++ if (task_stack_end_corrupted(current)) |
8127 |
++ pr_emerg("Thread overran stack, or stack corrupted\n"); |
8128 |
++ |
8129 |
++ debug_show_held_locks(current); |
8130 |
++ if (irqs_disabled()) |
8131 |
++ print_irqtrace_events(current); |
8132 |
++ |
8133 |
++ print_preempt_disable_ip(offsets & MIGHT_RESCHED_PREEMPT_MASK, |
8134 |
++ preempt_disable_ip); |
8135 |
++ |
8136 |
++ dump_stack(); |
8137 |
++ add_taint(TAINT_WARN, LOCKDEP_STILL_OK); |
8138 |
++} |
8139 |
++EXPORT_SYMBOL(__might_resched); |
8140 |
++ |
8141 |
++void __cant_sleep(const char *file, int line, int preempt_offset) |
8142 |
++{ |
8143 |
++ static unsigned long prev_jiffy; |
8144 |
++ |
8145 |
++ if (irqs_disabled()) |
8146 |
++ return; |
8147 |
++ |
8148 |
++ if (!IS_ENABLED(CONFIG_PREEMPT_COUNT)) |
8149 |
++ return; |
8150 |
++ |
8151 |
++ if (preempt_count() > preempt_offset) |
8152 |
++ return; |
8153 |
++ |
8154 |
++ if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) |
8155 |
++ return; |
8156 |
++ prev_jiffy = jiffies; |
8157 |
++ |
8158 |
++ printk(KERN_ERR "BUG: assuming atomic context at %s:%d\n", file, line); |
8159 |
++ printk(KERN_ERR "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", |
8160 |
++ in_atomic(), irqs_disabled(), |
8161 |
++ current->pid, current->comm); |
8162 |
++ |
8163 |
++ debug_show_held_locks(current); |
8164 |
++ dump_stack(); |
8165 |
++ add_taint(TAINT_WARN, LOCKDEP_STILL_OK); |
8166 |
++} |
8167 |
++EXPORT_SYMBOL_GPL(__cant_sleep); |
8168 |
++ |
8169 |
++#ifdef CONFIG_SMP |
8170 |
++void __cant_migrate(const char *file, int line) |
8171 |
++{ |
8172 |
++ static unsigned long prev_jiffy; |
8173 |
++ |
8174 |
++ if (irqs_disabled()) |
8175 |
++ return; |
8176 |
++ |
8177 |
++ if (is_migration_disabled(current)) |
8178 |
++ return; |
8179 |
++ |
8180 |
++ if (!IS_ENABLED(CONFIG_PREEMPT_COUNT)) |
8181 |
++ return; |
8182 |
++ |
8183 |
++ if (preempt_count() > 0) |
8184 |
++ return; |
8185 |
++ |
8186 |
++ if (current->migration_flags & MDF_FORCE_ENABLED) |
8187 |
++ return; |
8188 |
++ |
8189 |
++ if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) |
8190 |
++ return; |
8191 |
++ prev_jiffy = jiffies; |
8192 |
++ |
8193 |
++ pr_err("BUG: assuming non migratable context at %s:%d\n", file, line); |
8194 |
++ pr_err("in_atomic(): %d, irqs_disabled(): %d, migration_disabled() %u pid: %d, name: %s\n", |
8195 |
++ in_atomic(), irqs_disabled(), is_migration_disabled(current), |
8196 |
++ current->pid, current->comm); |
8197 |
++ |
8198 |
++ debug_show_held_locks(current); |
8199 |
++ dump_stack(); |
8200 |
++ add_taint(TAINT_WARN, LOCKDEP_STILL_OK); |
8201 |
++} |
8202 |
++EXPORT_SYMBOL_GPL(__cant_migrate); |
8203 |
++#endif |
8204 |
++#endif |
8205 |
++ |
8206 |
++#ifdef CONFIG_MAGIC_SYSRQ |
8207 |
++void normalize_rt_tasks(void) |
8208 |
++{ |
8209 |
++ struct task_struct *g, *p; |
8210 |
++ struct sched_attr attr = { |
8211 |
++ .sched_policy = SCHED_NORMAL, |
8212 |
++ }; |
8213 |
++ |
8214 |
++ read_lock(&tasklist_lock); |
8215 |
++ for_each_process_thread(g, p) { |
8216 |
++ /* |
8217 |
++ * Only normalize user tasks: |
8218 |
++ */ |
8219 |
++ if (p->flags & PF_KTHREAD) |
8220 |
++ continue; |
8221 |
++ |
8222 |
++ schedstat_set(p->stats.wait_start, 0); |
8223 |
++ schedstat_set(p->stats.sleep_start, 0); |
8224 |
++ schedstat_set(p->stats.block_start, 0); |
8225 |
++ |
8226 |
++ if (!rt_task(p)) { |
8227 |
++ /* |
8228 |
++ * Renice negative nice level userspace |
8229 |
++ * tasks back to 0: |
8230 |
++ */ |
8231 |
++ if (task_nice(p) < 0) |
8232 |
++ set_user_nice(p, 0); |
8233 |
++ continue; |
8234 |
++ } |
8235 |
++ |
8236 |
++ __sched_setscheduler(p, &attr, false, false); |
8237 |
++ } |
8238 |
++ read_unlock(&tasklist_lock); |
8239 |
++} |
8240 |
++#endif /* CONFIG_MAGIC_SYSRQ */ |
8241 |
++ |
8242 |
++#if defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) |
8243 |
++/* |
8244 |
++ * These functions are only useful for the IA64 MCA handling, or kdb. |
8245 |
++ * |
8246 |
++ * They can only be called when the whole system has been |
8247 |
++ * stopped - every CPU needs to be quiescent, and no scheduling |
8248 |
++ * activity can take place. Using them for anything else would |
8249 |
++ * be a serious bug, and as a result, they aren't even visible |
8250 |
++ * under any other configuration. |
8251 |
++ */ |
8252 |
++ |
8253 |
++/** |
8254 |
++ * curr_task - return the current task for a given CPU. |
8255 |
++ * @cpu: the processor in question. |
8256 |
++ * |
8257 |
++ * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! |
8258 |
++ * |
8259 |
++ * Return: The current task for @cpu. |
8260 |
++ */ |
8261 |
++struct task_struct *curr_task(int cpu) |
8262 |
++{ |
8263 |
++ return cpu_curr(cpu); |
8264 |
++} |
8265 |
++ |
8266 |
++#endif /* defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) */ |
8267 |
++ |
8268 |
++#ifdef CONFIG_IA64 |
8269 |
++/** |
8270 |
++ * ia64_set_curr_task - set the current task for a given CPU. |
8271 |
++ * @cpu: the processor in question. |
8272 |
++ * @p: the task pointer to set. |
8273 |
++ * |
8274 |
++ * Description: This function must only be used when non-maskable interrupts |
8275 |
++ * are serviced on a separate stack. It allows the architecture to switch the |
8276 |
++ * notion of the current task on a CPU in a non-blocking manner. This function |
8277 |
++ * must be called with all CPU's synchronised, and interrupts disabled, the |
8278 |
++ * and caller must save the original value of the current task (see |
8279 |
++ * curr_task() above) and restore that value before reenabling interrupts and |
8280 |
++ * re-starting the system. |
8281 |
++ * |
8282 |
++ * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! |
8283 |
++ */ |
8284 |
++void ia64_set_curr_task(int cpu, struct task_struct *p) |
8285 |
++{ |
8286 |
++ cpu_curr(cpu) = p; |
8287 |
++} |
8288 |
++ |
8289 |
++#endif |
8290 |
++ |
8291 |
++#ifdef CONFIG_CGROUP_SCHED |
8292 |
++static void sched_free_group(struct task_group *tg) |
8293 |
++{ |
8294 |
++ kmem_cache_free(task_group_cache, tg); |
8295 |
++} |
8296 |
++ |
8297 |
++static void sched_free_group_rcu(struct rcu_head *rhp) |
8298 |
++{ |
8299 |
++ sched_free_group(container_of(rhp, struct task_group, rcu)); |
8300 |
++} |
8301 |
++ |
8302 |
++static void sched_unregister_group(struct task_group *tg) |
8303 |
++{ |
8304 |
++ /* |
8305 |
++ * We have to wait for yet another RCU grace period to expire, as |
8306 |
++ * print_cfs_stats() might run concurrently. |
8307 |
++ */ |
8308 |
++ call_rcu(&tg->rcu, sched_free_group_rcu); |
8309 |
++} |
8310 |
++ |
8311 |
++/* allocate runqueue etc for a new task group */ |
8312 |
++struct task_group *sched_create_group(struct task_group *parent) |
8313 |
++{ |
8314 |
++ struct task_group *tg; |
8315 |
++ |
8316 |
++ tg = kmem_cache_alloc(task_group_cache, GFP_KERNEL | __GFP_ZERO); |
8317 |
++ if (!tg) |
8318 |
++ return ERR_PTR(-ENOMEM); |
8319 |
++ |
8320 |
++ return tg; |
8321 |
++} |
8322 |
++ |
8323 |
++void sched_online_group(struct task_group *tg, struct task_group *parent) |
8324 |
++{ |
8325 |
++} |
8326 |
++ |
8327 |
++/* rcu callback to free various structures associated with a task group */ |
8328 |
++static void sched_unregister_group_rcu(struct rcu_head *rhp) |
8329 |
++{ |
8330 |
++ /* Now it should be safe to free those cfs_rqs: */ |
8331 |
++ sched_unregister_group(container_of(rhp, struct task_group, rcu)); |
8332 |
++} |
8333 |
++ |
8334 |
++void sched_destroy_group(struct task_group *tg) |
8335 |
++{ |
8336 |
++ /* Wait for possible concurrent references to cfs_rqs complete: */ |
8337 |
++ call_rcu(&tg->rcu, sched_unregister_group_rcu); |
8338 |
++} |
8339 |
++ |
8340 |
++void sched_release_group(struct task_group *tg) |
8341 |
++{ |
8342 |
++} |
8343 |
++ |
8344 |
++static inline struct task_group *css_tg(struct cgroup_subsys_state *css) |
8345 |
++{ |
8346 |
++ return css ? container_of(css, struct task_group, css) : NULL; |
8347 |
++} |
8348 |
++ |
8349 |
++static struct cgroup_subsys_state * |
8350 |
++cpu_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) |
8351 |
++{ |
8352 |
++ struct task_group *parent = css_tg(parent_css); |
8353 |
++ struct task_group *tg; |
8354 |
++ |
8355 |
++ if (!parent) { |
8356 |
++ /* This is early initialization for the top cgroup */ |
8357 |
++ return &root_task_group.css; |
8358 |
++ } |
8359 |
++ |
8360 |
++ tg = sched_create_group(parent); |
8361 |
++ if (IS_ERR(tg)) |
8362 |
++ return ERR_PTR(-ENOMEM); |
8363 |
++ return &tg->css; |
8364 |
++} |
8365 |
++ |
8366 |
++/* Expose task group only after completing cgroup initialization */ |
8367 |
++static int cpu_cgroup_css_online(struct cgroup_subsys_state *css) |
8368 |
++{ |
8369 |
++ struct task_group *tg = css_tg(css); |
8370 |
++ struct task_group *parent = css_tg(css->parent); |
8371 |
++ |
8372 |
++ if (parent) |
8373 |
++ sched_online_group(tg, parent); |
8374 |
++ return 0; |
8375 |
++} |
8376 |
++ |
8377 |
++static void cpu_cgroup_css_released(struct cgroup_subsys_state *css) |
8378 |
++{ |
8379 |
++ struct task_group *tg = css_tg(css); |
8380 |
++ |
8381 |
++ sched_release_group(tg); |
8382 |
++} |
8383 |
++ |
8384 |
++static void cpu_cgroup_css_free(struct cgroup_subsys_state *css) |
8385 |
++{ |
8386 |
++ struct task_group *tg = css_tg(css); |
8387 |
++ |
8388 |
++ /* |
8389 |
++ * Relies on the RCU grace period between css_released() and this. |
8390 |
++ */ |
8391 |
++ sched_unregister_group(tg); |
8392 |
++} |
8393 |
++ |
8394 |
++static void cpu_cgroup_fork(struct task_struct *task) |
8395 |
++{ |
8396 |
++} |
8397 |
++ |
8398 |
++static int cpu_cgroup_can_attach(struct cgroup_taskset *tset) |
8399 |
++{ |
8400 |
++ return 0; |
8401 |
++} |
8402 |
++ |
8403 |
++static void cpu_cgroup_attach(struct cgroup_taskset *tset) |
8404 |
++{ |
8405 |
++} |
8406 |
++ |
8407 |
++#ifdef CONFIG_FAIR_GROUP_SCHED |
8408 |
++static DEFINE_MUTEX(shares_mutex); |
8409 |
++ |
8410 |
++int sched_group_set_shares(struct task_group *tg, unsigned long shares) |
8411 |
++{ |
8412 |
++ /* |
8413 |
++ * We can't change the weight of the root cgroup. |
8414 |
++ */ |
8415 |
++ if (&root_task_group == tg) |
8416 |
++ return -EINVAL; |
8417 |
++ |
8418 |
++ shares = clamp(shares, scale_load(MIN_SHARES), scale_load(MAX_SHARES)); |
8419 |
++ |
8420 |
++ mutex_lock(&shares_mutex); |
8421 |
++ if (tg->shares == shares) |
8422 |
++ goto done; |
8423 |
++ |
8424 |
++ tg->shares = shares; |
8425 |
++done: |
8426 |
++ mutex_unlock(&shares_mutex); |
8427 |
++ return 0; |
8428 |
++} |
8429 |
++ |
8430 |
++static int cpu_shares_write_u64(struct cgroup_subsys_state *css, |
8431 |
++ struct cftype *cftype, u64 shareval) |
8432 |
++{ |
8433 |
++ if (shareval > scale_load_down(ULONG_MAX)) |
8434 |
++ shareval = MAX_SHARES; |
8435 |
++ return sched_group_set_shares(css_tg(css), scale_load(shareval)); |
8436 |
++} |
8437 |
++ |
8438 |
++static u64 cpu_shares_read_u64(struct cgroup_subsys_state *css, |
8439 |
++ struct cftype *cft) |
8440 |
++{ |
8441 |
++ struct task_group *tg = css_tg(css); |
8442 |
++ |
8443 |
++ return (u64) scale_load_down(tg->shares); |
8444 |
++} |
8445 |
++#endif |
8446 |
++ |
8447 |
++static struct cftype cpu_legacy_files[] = { |
8448 |
++#ifdef CONFIG_FAIR_GROUP_SCHED |
8449 |
++ { |
8450 |
++ .name = "shares", |
8451 |
++ .read_u64 = cpu_shares_read_u64, |
8452 |
++ .write_u64 = cpu_shares_write_u64, |
8453 |
++ }, |
8454 |
++#endif |
8455 |
++ { } /* Terminate */ |
8456 |
++}; |
8457 |
++ |
8458 |
++ |
8459 |
++static struct cftype cpu_files[] = { |
8460 |
++ { } /* terminate */ |
8461 |
++}; |
8462 |
++ |
8463 |
++static int cpu_extra_stat_show(struct seq_file *sf, |
8464 |
++ struct cgroup_subsys_state *css) |
8465 |
++{ |
8466 |
++ return 0; |
8467 |
++} |
8468 |
++ |
8469 |
++struct cgroup_subsys cpu_cgrp_subsys = { |
8470 |
++ .css_alloc = cpu_cgroup_css_alloc, |
8471 |
++ .css_online = cpu_cgroup_css_online, |
8472 |
++ .css_released = cpu_cgroup_css_released, |
8473 |
++ .css_free = cpu_cgroup_css_free, |
8474 |
++ .css_extra_stat_show = cpu_extra_stat_show, |
8475 |
++ .fork = cpu_cgroup_fork, |
8476 |
++ .can_attach = cpu_cgroup_can_attach, |
8477 |
++ .attach = cpu_cgroup_attach, |
8478 |
++ .legacy_cftypes = cpu_files, |
8479 |
++ .legacy_cftypes = cpu_legacy_files, |
8480 |
++ .dfl_cftypes = cpu_files, |
8481 |
++ .early_init = true, |
8482 |
++ .threaded = true, |
8483 |
++}; |
8484 |
++#endif /* CONFIG_CGROUP_SCHED */ |
8485 |
++ |
8486 |
++#undef CREATE_TRACE_POINTS |
8487 |
+diff --git a/kernel/sched/alt_debug.c b/kernel/sched/alt_debug.c |
8488 |
+new file mode 100644 |
8489 |
+index 000000000000..1212a031700e |
8490 |
+--- /dev/null |
8491 |
++++ b/kernel/sched/alt_debug.c |
8492 |
+@@ -0,0 +1,31 @@ |
8493 |
++/* |
8494 |
++ * kernel/sched/alt_debug.c |
8495 |
++ * |
8496 |
++ * Print the alt scheduler debugging details |
8497 |
++ * |
8498 |
++ * Author: Alfred Chen |
8499 |
++ * Date : 2020 |
8500 |
++ */ |
8501 |
++#include "sched.h" |
8502 |
++ |
8503 |
++/* |
8504 |
++ * This allows printing both to /proc/sched_debug and |
8505 |
++ * to the console |
8506 |
++ */ |
8507 |
++#define SEQ_printf(m, x...) \ |
8508 |
++ do { \ |
8509 |
++ if (m) \ |
8510 |
++ seq_printf(m, x); \ |
8511 |
++ else \ |
8512 |
++ pr_cont(x); \ |
8513 |
++ } while (0) |
8514 |
++ |
8515 |
++void proc_sched_show_task(struct task_struct *p, struct pid_namespace *ns, |
8516 |
++ struct seq_file *m) |
8517 |
++{ |
8518 |
++ SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, task_pid_nr_ns(p, ns), |
8519 |
++ get_nr_threads(p)); |
8520 |
++} |
8521 |
++ |
8522 |
++void proc_sched_set_task(struct task_struct *p) |
8523 |
++{} |
8524 |
+diff --git a/kernel/sched/alt_sched.h b/kernel/sched/alt_sched.h |
8525 |
+new file mode 100644 |
8526 |
+index 000000000000..a181bf9ce57d |
8527 |
+--- /dev/null |
8528 |
++++ b/kernel/sched/alt_sched.h |
8529 |
+@@ -0,0 +1,645 @@ |
8530 |
++#ifndef ALT_SCHED_H |
8531 |
++#define ALT_SCHED_H |
8532 |
++ |
8533 |
++#include <linux/psi.h> |
8534 |
++#include <linux/stop_machine.h> |
8535 |
++#include <linux/syscalls.h> |
8536 |
++#include <linux/tick.h> |
8537 |
++ |
8538 |
++#include <trace/events/power.h> |
8539 |
++#include <trace/events/sched.h> |
8540 |
++ |
8541 |
++#include "../workqueue_internal.h" |
8542 |
++ |
8543 |
++#include "cpupri.h" |
8544 |
++ |
8545 |
++#ifdef CONFIG_SCHED_BMQ |
8546 |
++/* bits: |
8547 |
++ * RT(0-99), (Low prio adj range, nice width, high prio adj range) / 2, cpu idle task */ |
8548 |
++#define SCHED_BITS (MAX_RT_PRIO + NICE_WIDTH / 2 + MAX_PRIORITY_ADJ + 1) |
8549 |
++#endif |
8550 |
++ |
8551 |
++#ifdef CONFIG_SCHED_PDS |
8552 |
++/* bits: RT(0-99), reserved(100-127), NORMAL_PRIO_NUM, cpu idle task */ |
8553 |
++#define SCHED_BITS (MIN_NORMAL_PRIO + NORMAL_PRIO_NUM + 1) |
8554 |
++#endif /* CONFIG_SCHED_PDS */ |
8555 |
++ |
8556 |
++#define IDLE_TASK_SCHED_PRIO (SCHED_BITS - 1) |
8557 |
++ |
8558 |
++#ifdef CONFIG_SCHED_DEBUG |
8559 |
++# define SCHED_WARN_ON(x) WARN_ONCE(x, #x) |
8560 |
++extern void resched_latency_warn(int cpu, u64 latency); |
8561 |
++#else |
8562 |
++# define SCHED_WARN_ON(x) ({ (void)(x), 0; }) |
8563 |
++static inline void resched_latency_warn(int cpu, u64 latency) {} |
8564 |
++#endif |
8565 |
++ |
8566 |
++/* |
8567 |
++ * Increase resolution of nice-level calculations for 64-bit architectures. |
8568 |
++ * The extra resolution improves shares distribution and load balancing of |
8569 |
++ * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup |
8570 |
++ * hierarchies, especially on larger systems. This is not a user-visible change |
8571 |
++ * and does not change the user-interface for setting shares/weights. |
8572 |
++ * |
8573 |
++ * We increase resolution only if we have enough bits to allow this increased |
8574 |
++ * resolution (i.e. 64-bit). The costs for increasing resolution when 32-bit |
8575 |
++ * are pretty high and the returns do not justify the increased costs. |
8576 |
++ * |
8577 |
++ * Really only required when CONFIG_FAIR_GROUP_SCHED=y is also set, but to |
8578 |
++ * increase coverage and consistency always enable it on 64-bit platforms. |
8579 |
++ */ |
8580 |
++#ifdef CONFIG_64BIT |
8581 |
++# define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT + SCHED_FIXEDPOINT_SHIFT) |
8582 |
++# define scale_load(w) ((w) << SCHED_FIXEDPOINT_SHIFT) |
8583 |
++# define scale_load_down(w) \ |
8584 |
++({ \ |
8585 |
++ unsigned long __w = (w); \ |
8586 |
++ if (__w) \ |
8587 |
++ __w = max(2UL, __w >> SCHED_FIXEDPOINT_SHIFT); \ |
8588 |
++ __w; \ |
8589 |
++}) |
8590 |
++#else |
8591 |
++# define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT) |
8592 |
++# define scale_load(w) (w) |
8593 |
++# define scale_load_down(w) (w) |
8594 |
++#endif |
8595 |
++ |
8596 |
++#ifdef CONFIG_FAIR_GROUP_SCHED |
8597 |
++#define ROOT_TASK_GROUP_LOAD NICE_0_LOAD |
8598 |
++ |
8599 |
++/* |
8600 |
++ * A weight of 0 or 1 can cause arithmetics problems. |
8601 |
++ * A weight of a cfs_rq is the sum of weights of which entities |
8602 |
++ * are queued on this cfs_rq, so a weight of a entity should not be |
8603 |
++ * too large, so as the shares value of a task group. |
8604 |
++ * (The default weight is 1024 - so there's no practical |
8605 |
++ * limitation from this.) |
8606 |
++ */ |
8607 |
++#define MIN_SHARES (1UL << 1) |
8608 |
++#define MAX_SHARES (1UL << 18) |
8609 |
++#endif |
8610 |
++ |
8611 |
++/* task_struct::on_rq states: */ |
8612 |
++#define TASK_ON_RQ_QUEUED 1 |
8613 |
++#define TASK_ON_RQ_MIGRATING 2 |
8614 |
++ |
8615 |
++static inline int task_on_rq_queued(struct task_struct *p) |
8616 |
++{ |
8617 |
++ return p->on_rq == TASK_ON_RQ_QUEUED; |
8618 |
++} |
8619 |
++ |
8620 |
++static inline int task_on_rq_migrating(struct task_struct *p) |
8621 |
++{ |
8622 |
++ return READ_ONCE(p->on_rq) == TASK_ON_RQ_MIGRATING; |
8623 |
++} |
8624 |
++ |
8625 |
++/* |
8626 |
++ * wake flags |
8627 |
++ */ |
8628 |
++#define WF_SYNC 0x01 /* waker goes to sleep after wakeup */ |
8629 |
++#define WF_FORK 0x02 /* child wakeup after fork */ |
8630 |
++#define WF_MIGRATED 0x04 /* internal use, task got migrated */ |
8631 |
++#define WF_ON_CPU 0x08 /* Wakee is on_rq */ |
8632 |
++ |
8633 |
++#define SCHED_QUEUE_BITS (SCHED_BITS - 1) |
8634 |
++ |
8635 |
++struct sched_queue { |
8636 |
++ DECLARE_BITMAP(bitmap, SCHED_QUEUE_BITS); |
8637 |
++ struct list_head heads[SCHED_BITS]; |
8638 |
++}; |
8639 |
++ |
8640 |
++/* |
8641 |
++ * This is the main, per-CPU runqueue data structure. |
8642 |
++ * This data should only be modified by the local cpu. |
8643 |
++ */ |
8644 |
++struct rq { |
8645 |
++ /* runqueue lock: */ |
8646 |
++ raw_spinlock_t lock; |
8647 |
++ |
8648 |
++ struct task_struct __rcu *curr; |
8649 |
++ struct task_struct *idle, *stop, *skip; |
8650 |
++ struct mm_struct *prev_mm; |
8651 |
++ |
8652 |
++ struct sched_queue queue; |
8653 |
++#ifdef CONFIG_SCHED_PDS |
8654 |
++ u64 time_edge; |
8655 |
++#endif |
8656 |
++ unsigned long watermark; |
8657 |
++ |
8658 |
++ /* switch count */ |
8659 |
++ u64 nr_switches; |
8660 |
++ |
8661 |
++ atomic_t nr_iowait; |
8662 |
++ |
8663 |
++#ifdef CONFIG_SCHED_DEBUG |
8664 |
++ u64 last_seen_need_resched_ns; |
8665 |
++ int ticks_without_resched; |
8666 |
++#endif |
8667 |
++ |
8668 |
++#ifdef CONFIG_MEMBARRIER |
8669 |
++ int membarrier_state; |
8670 |
++#endif |
8671 |
++ |
8672 |
++#ifdef CONFIG_SMP |
8673 |
++ int cpu; /* cpu of this runqueue */ |
8674 |
++ bool online; |
8675 |
++ |
8676 |
++ unsigned int ttwu_pending; |
8677 |
++ unsigned char nohz_idle_balance; |
8678 |
++ unsigned char idle_balance; |
8679 |
++ |
8680 |
++#ifdef CONFIG_HAVE_SCHED_AVG_IRQ |
8681 |
++ struct sched_avg avg_irq; |
8682 |
++#endif |
8683 |
++ |
8684 |
++#ifdef CONFIG_SCHED_SMT |
8685 |
++ int active_balance; |
8686 |
++ struct cpu_stop_work active_balance_work; |
8687 |
++#endif |
8688 |
++ struct callback_head *balance_callback; |
8689 |
++#ifdef CONFIG_HOTPLUG_CPU |
8690 |
++ struct rcuwait hotplug_wait; |
8691 |
++#endif |
8692 |
++ unsigned int nr_pinned; |
8693 |
++ |
8694 |
++#endif /* CONFIG_SMP */ |
8695 |
++#ifdef CONFIG_IRQ_TIME_ACCOUNTING |
8696 |
++ u64 prev_irq_time; |
8697 |
++#endif /* CONFIG_IRQ_TIME_ACCOUNTING */ |
8698 |
++#ifdef CONFIG_PARAVIRT |
8699 |
++ u64 prev_steal_time; |
8700 |
++#endif /* CONFIG_PARAVIRT */ |
8701 |
++#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING |
8702 |
++ u64 prev_steal_time_rq; |
8703 |
++#endif /* CONFIG_PARAVIRT_TIME_ACCOUNTING */ |
8704 |
++ |
8705 |
++ /* For genenal cpu load util */ |
8706 |
++ s32 load_history; |
8707 |
++ u64 load_block; |
8708 |
++ u64 load_stamp; |
8709 |
++ |
8710 |
++ /* calc_load related fields */ |
8711 |
++ unsigned long calc_load_update; |
8712 |
++ long calc_load_active; |
8713 |
++ |
8714 |
++ u64 clock, last_tick; |
8715 |
++ u64 last_ts_switch; |
8716 |
++ u64 clock_task; |
8717 |
++ |
8718 |
++ unsigned int nr_running; |
8719 |
++ unsigned long nr_uninterruptible; |
8720 |
++ |
8721 |
++#ifdef CONFIG_SCHED_HRTICK |
8722 |
++#ifdef CONFIG_SMP |
8723 |
++ call_single_data_t hrtick_csd; |
8724 |
++#endif |
8725 |
++ struct hrtimer hrtick_timer; |
8726 |
++ ktime_t hrtick_time; |
8727 |
++#endif |
8728 |
++ |
8729 |
++#ifdef CONFIG_SCHEDSTATS |
8730 |
++ |
8731 |
++ /* latency stats */ |
8732 |
++ struct sched_info rq_sched_info; |
8733 |
++ unsigned long long rq_cpu_time; |
8734 |
++ /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ |
8735 |
++ |
8736 |
++ /* sys_sched_yield() stats */ |
8737 |
++ unsigned int yld_count; |
8738 |
++ |
8739 |
++ /* schedule() stats */ |
8740 |
++ unsigned int sched_switch; |
8741 |
++ unsigned int sched_count; |
8742 |
++ unsigned int sched_goidle; |
8743 |
++ |
8744 |
++ /* try_to_wake_up() stats */ |
8745 |
++ unsigned int ttwu_count; |
8746 |
++ unsigned int ttwu_local; |
8747 |
++#endif /* CONFIG_SCHEDSTATS */ |
8748 |
++ |
8749 |
++#ifdef CONFIG_CPU_IDLE |
8750 |
++ /* Must be inspected within a rcu lock section */ |
8751 |
++ struct cpuidle_state *idle_state; |
8752 |
++#endif |
8753 |
++ |
8754 |
++#ifdef CONFIG_NO_HZ_COMMON |
8755 |
++#ifdef CONFIG_SMP |
8756 |
++ call_single_data_t nohz_csd; |
8757 |
++#endif |
8758 |
++ atomic_t nohz_flags; |
8759 |
++#endif /* CONFIG_NO_HZ_COMMON */ |
8760 |
++}; |
8761 |
++ |
8762 |
++extern unsigned long rq_load_util(struct rq *rq, unsigned long max); |
8763 |
++ |
8764 |
++extern unsigned long calc_load_update; |
8765 |
++extern atomic_long_t calc_load_tasks; |
8766 |
++ |
8767 |
++extern void calc_global_load_tick(struct rq *this_rq); |
8768 |
++extern long calc_load_fold_active(struct rq *this_rq, long adjust); |
8769 |
++ |
8770 |
++DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); |
8771 |
++#define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) |
8772 |
++#define this_rq() this_cpu_ptr(&runqueues) |
8773 |
++#define task_rq(p) cpu_rq(task_cpu(p)) |
8774 |
++#define cpu_curr(cpu) (cpu_rq(cpu)->curr) |
8775 |
++#define raw_rq() raw_cpu_ptr(&runqueues) |
8776 |
++ |
8777 |
++#ifdef CONFIG_SMP |
8778 |
++#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) |
8779 |
++void register_sched_domain_sysctl(void); |
8780 |
++void unregister_sched_domain_sysctl(void); |
8781 |
++#else |
8782 |
++static inline void register_sched_domain_sysctl(void) |
8783 |
++{ |
8784 |
++} |
8785 |
++static inline void unregister_sched_domain_sysctl(void) |
8786 |
++{ |
8787 |
++} |
8788 |
++#endif |
8789 |
++ |
8790 |
++extern bool sched_smp_initialized; |
8791 |
++ |
8792 |
++enum { |
8793 |
++ ITSELF_LEVEL_SPACE_HOLDER, |
8794 |
++#ifdef CONFIG_SCHED_SMT |
8795 |
++ SMT_LEVEL_SPACE_HOLDER, |
8796 |
++#endif |
8797 |
++ COREGROUP_LEVEL_SPACE_HOLDER, |
8798 |
++ CORE_LEVEL_SPACE_HOLDER, |
8799 |
++ OTHER_LEVEL_SPACE_HOLDER, |
8800 |
++ NR_CPU_AFFINITY_LEVELS |
8801 |
++}; |
8802 |
++ |
8803 |
++DECLARE_PER_CPU(cpumask_t [NR_CPU_AFFINITY_LEVELS], sched_cpu_topo_masks); |
8804 |
++DECLARE_PER_CPU(cpumask_t *, sched_cpu_llc_mask); |
8805 |
++ |
8806 |
++static inline int |
8807 |
++__best_mask_cpu(const cpumask_t *cpumask, const cpumask_t *mask) |
8808 |
++{ |
8809 |
++ int cpu; |
8810 |
++ |
8811 |
++ while ((cpu = cpumask_any_and(cpumask, mask)) >= nr_cpu_ids) |
8812 |
++ mask++; |
8813 |
++ |
8814 |
++ return cpu; |
8815 |
++} |
8816 |
++ |
8817 |
++static inline int best_mask_cpu(int cpu, const cpumask_t *mask) |
8818 |
++{ |
8819 |
++ return __best_mask_cpu(mask, per_cpu(sched_cpu_topo_masks, cpu)); |
8820 |
++} |
8821 |
++ |
8822 |
++extern void flush_smp_call_function_queue(void); |
8823 |
++ |
8824 |
++#else /* !CONFIG_SMP */ |
8825 |
++static inline void flush_smp_call_function_queue(void) { } |
8826 |
++#endif |
8827 |
++ |
8828 |
++#ifndef arch_scale_freq_tick |
8829 |
++static __always_inline |
8830 |
++void arch_scale_freq_tick(void) |
8831 |
++{ |
8832 |
++} |
8833 |
++#endif |
8834 |
++ |
8835 |
++#ifndef arch_scale_freq_capacity |
8836 |
++static __always_inline |
8837 |
++unsigned long arch_scale_freq_capacity(int cpu) |
8838 |
++{ |
8839 |
++ return SCHED_CAPACITY_SCALE; |
8840 |
++} |
8841 |
++#endif |
8842 |
++ |
8843 |
++static inline u64 __rq_clock_broken(struct rq *rq) |
8844 |
++{ |
8845 |
++ return READ_ONCE(rq->clock); |
8846 |
++} |
8847 |
++ |
8848 |
++static inline u64 rq_clock(struct rq *rq) |
8849 |
++{ |
8850 |
++ /* |
8851 |
++ * Relax lockdep_assert_held() checking as in VRQ, call to |
8852 |
++ * sched_info_xxxx() may not held rq->lock |
8853 |
++ * lockdep_assert_held(&rq->lock); |
8854 |
++ */ |
8855 |
++ return rq->clock; |
8856 |
++} |
8857 |
++ |
8858 |
++static inline u64 rq_clock_task(struct rq *rq) |
8859 |
++{ |
8860 |
++ /* |
8861 |
++ * Relax lockdep_assert_held() checking as in VRQ, call to |
8862 |
++ * sched_info_xxxx() may not held rq->lock |
8863 |
++ * lockdep_assert_held(&rq->lock); |
8864 |
++ */ |
8865 |
++ return rq->clock_task; |
8866 |
++} |
8867 |
++ |
8868 |
++/* |
8869 |
++ * {de,en}queue flags: |
8870 |
++ * |
8871 |
++ * DEQUEUE_SLEEP - task is no longer runnable |
8872 |
++ * ENQUEUE_WAKEUP - task just became runnable |
8873 |
++ * |
8874 |
++ */ |
8875 |
++ |
8876 |
++#define DEQUEUE_SLEEP 0x01 |
8877 |
++ |
8878 |
++#define ENQUEUE_WAKEUP 0x01 |
8879 |
++ |
8880 |
++ |
8881 |
++/* |
8882 |
++ * Below are scheduler API which using in other kernel code |
8883 |
++ * It use the dummy rq_flags |
8884 |
++ * ToDo : BMQ need to support these APIs for compatibility with mainline |
8885 |
++ * scheduler code. |
8886 |
++ */ |
8887 |
++struct rq_flags { |
8888 |
++ unsigned long flags; |
8889 |
++}; |
8890 |
++ |
8891 |
++struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf) |
8892 |
++ __acquires(rq->lock); |
8893 |
++ |
8894 |
++struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) |
8895 |
++ __acquires(p->pi_lock) |
8896 |
++ __acquires(rq->lock); |
8897 |
++ |
8898 |
++static inline void __task_rq_unlock(struct rq *rq, struct rq_flags *rf) |
8899 |
++ __releases(rq->lock) |
8900 |
++{ |
8901 |
++ raw_spin_unlock(&rq->lock); |
8902 |
++} |
8903 |
++ |
8904 |
++static inline void |
8905 |
++task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf) |
8906 |
++ __releases(rq->lock) |
8907 |
++ __releases(p->pi_lock) |
8908 |
++{ |
8909 |
++ raw_spin_unlock(&rq->lock); |
8910 |
++ raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags); |
8911 |
++} |
8912 |
++ |
8913 |
++static inline void |
8914 |
++rq_lock(struct rq *rq, struct rq_flags *rf) |
8915 |
++ __acquires(rq->lock) |
8916 |
++{ |
8917 |
++ raw_spin_lock(&rq->lock); |
8918 |
++} |
8919 |
++ |
8920 |
++static inline void |
8921 |
++rq_unlock_irq(struct rq *rq, struct rq_flags *rf) |
8922 |
++ __releases(rq->lock) |
8923 |
++{ |
8924 |
++ raw_spin_unlock_irq(&rq->lock); |
8925 |
++} |
8926 |
++ |
8927 |
++static inline void |
8928 |
++rq_unlock(struct rq *rq, struct rq_flags *rf) |
8929 |
++ __releases(rq->lock) |
8930 |
++{ |
8931 |
++ raw_spin_unlock(&rq->lock); |
8932 |
++} |
8933 |
++ |
8934 |
++static inline struct rq * |
8935 |
++this_rq_lock_irq(struct rq_flags *rf) |
8936 |
++ __acquires(rq->lock) |
8937 |
++{ |
8938 |
++ struct rq *rq; |
8939 |
++ |
8940 |
++ local_irq_disable(); |
8941 |
++ rq = this_rq(); |
8942 |
++ raw_spin_lock(&rq->lock); |
8943 |
++ |
8944 |
++ return rq; |
8945 |
++} |
8946 |
++ |
8947 |
++static inline raw_spinlock_t *__rq_lockp(struct rq *rq) |
8948 |
++{ |
8949 |
++ return &rq->lock; |
8950 |
++} |
8951 |
++ |
8952 |
++static inline raw_spinlock_t *rq_lockp(struct rq *rq) |
8953 |
++{ |
8954 |
++ return __rq_lockp(rq); |
8955 |
++} |
8956 |
++ |
8957 |
++static inline void lockdep_assert_rq_held(struct rq *rq) |
8958 |
++{ |
8959 |
++ lockdep_assert_held(__rq_lockp(rq)); |
8960 |
++} |
8961 |
++ |
8962 |
++extern void raw_spin_rq_lock_nested(struct rq *rq, int subclass); |
8963 |
++extern void raw_spin_rq_unlock(struct rq *rq); |
8964 |
++ |
8965 |
++static inline void raw_spin_rq_lock(struct rq *rq) |
8966 |
++{ |
8967 |
++ raw_spin_rq_lock_nested(rq, 0); |
8968 |
++} |
8969 |
++ |
8970 |
++static inline void raw_spin_rq_lock_irq(struct rq *rq) |
8971 |
++{ |
8972 |
++ local_irq_disable(); |
8973 |
++ raw_spin_rq_lock(rq); |
8974 |
++} |
8975 |
++ |
8976 |
++static inline void raw_spin_rq_unlock_irq(struct rq *rq) |
8977 |
++{ |
8978 |
++ raw_spin_rq_unlock(rq); |
8979 |
++ local_irq_enable(); |
8980 |
++} |
8981 |
++ |
8982 |
++static inline int task_current(struct rq *rq, struct task_struct *p) |
8983 |
++{ |
8984 |
++ return rq->curr == p; |
8985 |
++} |
8986 |
++ |
8987 |
++static inline bool task_running(struct task_struct *p) |
8988 |
++{ |
8989 |
++ return p->on_cpu; |
8990 |
++} |
8991 |
++ |
8992 |
++extern int task_running_nice(struct task_struct *p); |
8993 |
++ |
8994 |
++extern struct static_key_false sched_schedstats; |
8995 |
++ |
8996 |
++#ifdef CONFIG_CPU_IDLE |
8997 |
++static inline void idle_set_state(struct rq *rq, |
8998 |
++ struct cpuidle_state *idle_state) |
8999 |
++{ |
9000 |
++ rq->idle_state = idle_state; |
9001 |
++} |
9002 |
++ |
9003 |
++static inline struct cpuidle_state *idle_get_state(struct rq *rq) |
9004 |
++{ |
9005 |
++ WARN_ON(!rcu_read_lock_held()); |
9006 |
++ return rq->idle_state; |
9007 |
++} |
9008 |
++#else |
9009 |
++static inline void idle_set_state(struct rq *rq, |
9010 |
++ struct cpuidle_state *idle_state) |
9011 |
++{ |
9012 |
++} |
9013 |
++ |
9014 |
++static inline struct cpuidle_state *idle_get_state(struct rq *rq) |
9015 |
++{ |
9016 |
++ return NULL; |
9017 |
++} |
9018 |
++#endif |
9019 |
++ |
9020 |
++static inline int cpu_of(const struct rq *rq) |
9021 |
++{ |
9022 |
++#ifdef CONFIG_SMP |
9023 |
++ return rq->cpu; |
9024 |
++#else |
9025 |
++ return 0; |
9026 |
++#endif |
9027 |
++} |
9028 |
++ |
9029 |
++#include "stats.h" |
9030 |
++ |
9031 |
++#ifdef CONFIG_NO_HZ_COMMON |
9032 |
++#define NOHZ_BALANCE_KICK_BIT 0 |
9033 |
++#define NOHZ_STATS_KICK_BIT 1 |
9034 |
++ |
9035 |
++#define NOHZ_BALANCE_KICK BIT(NOHZ_BALANCE_KICK_BIT) |
9036 |
++#define NOHZ_STATS_KICK BIT(NOHZ_STATS_KICK_BIT) |
9037 |
++ |
9038 |
++#define NOHZ_KICK_MASK (NOHZ_BALANCE_KICK | NOHZ_STATS_KICK) |
9039 |
++ |
9040 |
++#define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags) |
9041 |
++ |
9042 |
++/* TODO: needed? |
9043 |
++extern void nohz_balance_exit_idle(struct rq *rq); |
9044 |
++#else |
9045 |
++static inline void nohz_balance_exit_idle(struct rq *rq) { } |
9046 |
++*/ |
9047 |
++#endif |
9048 |
++ |
9049 |
++#ifdef CONFIG_IRQ_TIME_ACCOUNTING |
9050 |
++struct irqtime { |
9051 |
++ u64 total; |
9052 |
++ u64 tick_delta; |
9053 |
++ u64 irq_start_time; |
9054 |
++ struct u64_stats_sync sync; |
9055 |
++}; |
9056 |
++ |
9057 |
++DECLARE_PER_CPU(struct irqtime, cpu_irqtime); |
9058 |
++ |
9059 |
++/* |
9060 |
++ * Returns the irqtime minus the softirq time computed by ksoftirqd. |
9061 |
++ * Otherwise ksoftirqd's sum_exec_runtime is substracted its own runtime |
9062 |
++ * and never move forward. |
9063 |
++ */ |
9064 |
++static inline u64 irq_time_read(int cpu) |
9065 |
++{ |
9066 |
++ struct irqtime *irqtime = &per_cpu(cpu_irqtime, cpu); |
9067 |
++ unsigned int seq; |
9068 |
++ u64 total; |
9069 |
++ |
9070 |
++ do { |
9071 |
++ seq = __u64_stats_fetch_begin(&irqtime->sync); |
9072 |
++ total = irqtime->total; |
9073 |
++ } while (__u64_stats_fetch_retry(&irqtime->sync, seq)); |
9074 |
++ |
9075 |
++ return total; |
9076 |
++} |
9077 |
++#endif /* CONFIG_IRQ_TIME_ACCOUNTING */ |
9078 |
++ |
9079 |
++#ifdef CONFIG_CPU_FREQ |
9080 |
++DECLARE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data); |
9081 |
++#endif /* CONFIG_CPU_FREQ */ |
9082 |
++ |
9083 |
++#ifdef CONFIG_NO_HZ_FULL |
9084 |
++extern int __init sched_tick_offload_init(void); |
9085 |
++#else |
9086 |
++static inline int sched_tick_offload_init(void) { return 0; } |
9087 |
++#endif |
9088 |
++ |
9089 |
++#ifdef arch_scale_freq_capacity |
9090 |
++#ifndef arch_scale_freq_invariant |
9091 |
++#define arch_scale_freq_invariant() (true) |
9092 |
++#endif |
9093 |
++#else /* arch_scale_freq_capacity */ |
9094 |
++#define arch_scale_freq_invariant() (false) |
9095 |
++#endif |
9096 |
++ |
9097 |
++extern void schedule_idle(void); |
9098 |
++ |
9099 |
++#define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT) |
9100 |
++ |
9101 |
++/* |
9102 |
++ * !! For sched_setattr_nocheck() (kernel) only !! |
9103 |
++ * |
9104 |
++ * This is actually gross. :( |
9105 |
++ * |
9106 |
++ * It is used to make schedutil kworker(s) higher priority than SCHED_DEADLINE |
9107 |
++ * tasks, but still be able to sleep. We need this on platforms that cannot |
9108 |
++ * atomically change clock frequency. Remove once fast switching will be |
9109 |
++ * available on such platforms. |
9110 |
++ * |
9111 |
++ * SUGOV stands for SchedUtil GOVernor. |
9112 |
++ */ |
9113 |
++#define SCHED_FLAG_SUGOV 0x10000000 |
9114 |
++ |
9115 |
++#ifdef CONFIG_MEMBARRIER |
9116 |
++/* |
9117 |
++ * The scheduler provides memory barriers required by membarrier between: |
9118 |
++ * - prior user-space memory accesses and store to rq->membarrier_state, |
9119 |
++ * - store to rq->membarrier_state and following user-space memory accesses. |
9120 |
++ * In the same way it provides those guarantees around store to rq->curr. |
9121 |
++ */ |
9122 |
++static inline void membarrier_switch_mm(struct rq *rq, |
9123 |
++ struct mm_struct *prev_mm, |
9124 |
++ struct mm_struct *next_mm) |
9125 |
++{ |
9126 |
++ int membarrier_state; |
9127 |
++ |
9128 |
++ if (prev_mm == next_mm) |
9129 |
++ return; |
9130 |
++ |
9131 |
++ membarrier_state = atomic_read(&next_mm->membarrier_state); |
9132 |
++ if (READ_ONCE(rq->membarrier_state) == membarrier_state) |
9133 |
++ return; |
9134 |
++ |
9135 |
++ WRITE_ONCE(rq->membarrier_state, membarrier_state); |
9136 |
++} |
9137 |
++#else |
9138 |
++static inline void membarrier_switch_mm(struct rq *rq, |
9139 |
++ struct mm_struct *prev_mm, |
9140 |
++ struct mm_struct *next_mm) |
9141 |
++{ |
9142 |
++} |
9143 |
++#endif |
9144 |
++ |
9145 |
++#ifdef CONFIG_NUMA |
9146 |
++extern int sched_numa_find_closest(const struct cpumask *cpus, int cpu); |
9147 |
++#else |
9148 |
++static inline int sched_numa_find_closest(const struct cpumask *cpus, int cpu) |
9149 |
++{ |
9150 |
++ return nr_cpu_ids; |
9151 |
++} |
9152 |
++#endif |
9153 |
++ |
9154 |
++extern void swake_up_all_locked(struct swait_queue_head *q); |
9155 |
++extern void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait); |
9156 |
++ |
9157 |
++#ifdef CONFIG_PREEMPT_DYNAMIC |
9158 |
++extern int preempt_dynamic_mode; |
9159 |
++extern int sched_dynamic_mode(const char *str); |
9160 |
++extern void sched_dynamic_update(int mode); |
9161 |
++#endif |
9162 |
++ |
9163 |
++static inline void nohz_run_idle_balance(int cpu) { } |
9164 |
++ |
9165 |
++static inline |
9166 |
++unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util, |
9167 |
++ struct task_struct *p) |
9168 |
++{ |
9169 |
++ return util; |
9170 |
++} |
9171 |
++ |
9172 |
++static inline bool uclamp_rq_is_capped(struct rq *rq) { return false; } |
9173 |
++ |
9174 |
++#endif /* ALT_SCHED_H */ |
9175 |
+diff --git a/kernel/sched/bmq.h b/kernel/sched/bmq.h |
9176 |
+new file mode 100644 |
9177 |
+index 000000000000..66b77291b9d0 |
9178 |
+--- /dev/null |
9179 |
++++ b/kernel/sched/bmq.h |
9180 |
+@@ -0,0 +1,110 @@ |
9181 |
++#define ALT_SCHED_VERSION_MSG "sched/bmq: BMQ CPU Scheduler "ALT_SCHED_VERSION" by Alfred Chen.\n" |
9182 |
++ |
9183 |
++/* |
9184 |
++ * BMQ only routines |
9185 |
++ */ |
9186 |
++#define rq_switch_time(rq) ((rq)->clock - (rq)->last_ts_switch) |
9187 |
++#define boost_threshold(p) (sched_timeslice_ns >>\ |
9188 |
++ (15 - MAX_PRIORITY_ADJ - (p)->boost_prio)) |
9189 |
++ |
9190 |
++static inline void boost_task(struct task_struct *p) |
9191 |
++{ |
9192 |
++ int limit; |
9193 |
++ |
9194 |
++ switch (p->policy) { |
9195 |
++ case SCHED_NORMAL: |
9196 |
++ limit = -MAX_PRIORITY_ADJ; |
9197 |
++ break; |
9198 |
++ case SCHED_BATCH: |
9199 |
++ case SCHED_IDLE: |
9200 |
++ limit = 0; |
9201 |
++ break; |
9202 |
++ default: |
9203 |
++ return; |
9204 |
++ } |
9205 |
++ |
9206 |
++ if (p->boost_prio > limit) |
9207 |
++ p->boost_prio--; |
9208 |
++} |
9209 |
++ |
9210 |
++static inline void deboost_task(struct task_struct *p) |
9211 |
++{ |
9212 |
++ if (p->boost_prio < MAX_PRIORITY_ADJ) |
9213 |
++ p->boost_prio++; |
9214 |
++} |
9215 |
++ |
9216 |
++/* |
9217 |
++ * Common interfaces |
9218 |
++ */ |
9219 |
++static inline void sched_timeslice_imp(const int timeslice_ms) {} |
9220 |
++ |
9221 |
++static inline int |
9222 |
++task_sched_prio_normal(const struct task_struct *p, const struct rq *rq) |
9223 |
++{ |
9224 |
++ return p->prio + p->boost_prio - MAX_RT_PRIO; |
9225 |
++} |
9226 |
++ |
9227 |
++static inline int task_sched_prio(const struct task_struct *p) |
9228 |
++{ |
9229 |
++ return (p->prio < MAX_RT_PRIO)? p->prio : MAX_RT_PRIO / 2 + (p->prio + p->boost_prio) / 2; |
9230 |
++} |
9231 |
++ |
9232 |
++static inline int |
9233 |
++task_sched_prio_idx(const struct task_struct *p, const struct rq *rq) |
9234 |
++{ |
9235 |
++ return task_sched_prio(p); |
9236 |
++} |
9237 |
++ |
9238 |
++static inline int sched_prio2idx(int prio, struct rq *rq) |
9239 |
++{ |
9240 |
++ return prio; |
9241 |
++} |
9242 |
++ |
9243 |
++static inline int sched_idx2prio(int idx, struct rq *rq) |
9244 |
++{ |
9245 |
++ return idx; |
9246 |
++} |
9247 |
++ |
9248 |
++static inline void time_slice_expired(struct task_struct *p, struct rq *rq) |
9249 |
++{ |
9250 |
++ p->time_slice = sched_timeslice_ns; |
9251 |
++ |
9252 |
++ if (SCHED_FIFO != p->policy && task_on_rq_queued(p)) { |
9253 |
++ if (SCHED_RR != p->policy) |
9254 |
++ deboost_task(p); |
9255 |
++ requeue_task(p, rq, task_sched_prio_idx(p, rq)); |
9256 |
++ } |
9257 |
++} |
9258 |
++ |
9259 |
++static inline void sched_task_sanity_check(struct task_struct *p, struct rq *rq) {} |
9260 |
++ |
9261 |
++inline int task_running_nice(struct task_struct *p) |
9262 |
++{ |
9263 |
++ return (p->prio + p->boost_prio > DEFAULT_PRIO + MAX_PRIORITY_ADJ); |
9264 |
++} |
9265 |
++ |
9266 |
++static void sched_task_fork(struct task_struct *p, struct rq *rq) |
9267 |
++{ |
9268 |
++ p->boost_prio = MAX_PRIORITY_ADJ; |
9269 |
++} |
9270 |
++ |
9271 |
++static inline void do_sched_yield_type_1(struct task_struct *p, struct rq *rq) |
9272 |
++{ |
9273 |
++ p->boost_prio = MAX_PRIORITY_ADJ; |
9274 |
++} |
9275 |
++ |
9276 |
++#ifdef CONFIG_SMP |
9277 |
++static inline void sched_task_ttwu(struct task_struct *p) |
9278 |
++{ |
9279 |
++ if(this_rq()->clock_task - p->last_ran > sched_timeslice_ns) |
9280 |
++ boost_task(p); |
9281 |
++} |
9282 |
++#endif |
9283 |
++ |
9284 |
++static inline void sched_task_deactivate(struct task_struct *p, struct rq *rq) |
9285 |
++{ |
9286 |
++ if (rq_switch_time(rq) < boost_threshold(p)) |
9287 |
++ boost_task(p); |
9288 |
++} |
9289 |
++ |
9290 |
++static inline void update_rq_time_edge(struct rq *rq) {} |
9291 |
+diff --git a/kernel/sched/build_policy.c b/kernel/sched/build_policy.c |
9292 |
+index d9dc9ab3773f..71a25540d65e 100644 |
9293 |
+--- a/kernel/sched/build_policy.c |
9294 |
++++ b/kernel/sched/build_policy.c |
9295 |
+@@ -42,13 +42,19 @@ |
9296 |
+ |
9297 |
+ #include "idle.c" |
9298 |
+ |
9299 |
++#ifndef CONFIG_SCHED_ALT |
9300 |
+ #include "rt.c" |
9301 |
++#endif |
9302 |
+ |
9303 |
+ #ifdef CONFIG_SMP |
9304 |
++#ifndef CONFIG_SCHED_ALT |
9305 |
+ # include "cpudeadline.c" |
9306 |
++#endif |
9307 |
+ # include "pelt.c" |
9308 |
+ #endif |
9309 |
+ |
9310 |
+ #include "cputime.c" |
9311 |
+-#include "deadline.c" |
9312 |
+ |
9313 |
++#ifndef CONFIG_SCHED_ALT |
9314 |
++#include "deadline.c" |
9315 |
++#endif |
9316 |
+diff --git a/kernel/sched/build_utility.c b/kernel/sched/build_utility.c |
9317 |
+index 99bdd96f454f..23f80a86d2d7 100644 |
9318 |
+--- a/kernel/sched/build_utility.c |
9319 |
++++ b/kernel/sched/build_utility.c |
9320 |
+@@ -85,7 +85,9 @@ |
9321 |
+ |
9322 |
+ #ifdef CONFIG_SMP |
9323 |
+ # include "cpupri.c" |
9324 |
++#ifndef CONFIG_SCHED_ALT |
9325 |
+ # include "stop_task.c" |
9326 |
++#endif |
9327 |
+ # include "topology.c" |
9328 |
+ #endif |
9329 |
+ |
9330 |
+diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c |
9331 |
+index 3dbf351d12d5..b2590f961139 100644 |
9332 |
+--- a/kernel/sched/cpufreq_schedutil.c |
9333 |
++++ b/kernel/sched/cpufreq_schedutil.c |
9334 |
+@@ -160,9 +160,14 @@ static void sugov_get_util(struct sugov_cpu *sg_cpu) |
9335 |
+ unsigned long max = arch_scale_cpu_capacity(sg_cpu->cpu); |
9336 |
+ |
9337 |
+ sg_cpu->max = max; |
9338 |
++#ifndef CONFIG_SCHED_ALT |
9339 |
+ sg_cpu->bw_dl = cpu_bw_dl(rq); |
9340 |
+ sg_cpu->util = effective_cpu_util(sg_cpu->cpu, cpu_util_cfs(sg_cpu->cpu), max, |
9341 |
+ FREQUENCY_UTIL, NULL); |
9342 |
++#else |
9343 |
++ sg_cpu->bw_dl = 0; |
9344 |
++ sg_cpu->util = rq_load_util(rq, max); |
9345 |
++#endif /* CONFIG_SCHED_ALT */ |
9346 |
+ } |
9347 |
+ |
9348 |
+ /** |
9349 |
+@@ -306,8 +311,10 @@ static inline bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu) { return false; } |
9350 |
+ */ |
9351 |
+ static inline void ignore_dl_rate_limit(struct sugov_cpu *sg_cpu) |
9352 |
+ { |
9353 |
++#ifndef CONFIG_SCHED_ALT |
9354 |
+ if (cpu_bw_dl(cpu_rq(sg_cpu->cpu)) > sg_cpu->bw_dl) |
9355 |
+ sg_cpu->sg_policy->limits_changed = true; |
9356 |
++#endif |
9357 |
+ } |
9358 |
+ |
9359 |
+ static inline bool sugov_update_single_common(struct sugov_cpu *sg_cpu, |
9360 |
+@@ -607,6 +614,7 @@ static int sugov_kthread_create(struct sugov_policy *sg_policy) |
9361 |
+ } |
9362 |
+ |
9363 |
+ ret = sched_setattr_nocheck(thread, &attr); |
9364 |
++ |
9365 |
+ if (ret) { |
9366 |
+ kthread_stop(thread); |
9367 |
+ pr_warn("%s: failed to set SCHED_DEADLINE\n", __func__); |
9368 |
+@@ -839,7 +847,9 @@ cpufreq_governor_init(schedutil_gov); |
9369 |
+ #ifdef CONFIG_ENERGY_MODEL |
9370 |
+ static void rebuild_sd_workfn(struct work_struct *work) |
9371 |
+ { |
9372 |
++#ifndef CONFIG_SCHED_ALT |
9373 |
+ rebuild_sched_domains_energy(); |
9374 |
++#endif /* CONFIG_SCHED_ALT */ |
9375 |
+ } |
9376 |
+ static DECLARE_WORK(rebuild_sd_work, rebuild_sd_workfn); |
9377 |
+ |
9378 |
+diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c |
9379 |
+index 78a233d43757..b3bbc87d4352 100644 |
9380 |
+--- a/kernel/sched/cputime.c |
9381 |
++++ b/kernel/sched/cputime.c |
9382 |
+@@ -122,7 +122,7 @@ void account_user_time(struct task_struct *p, u64 cputime) |
9383 |
+ p->utime += cputime; |
9384 |
+ account_group_user_time(p, cputime); |
9385 |
+ |
9386 |
+- index = (task_nice(p) > 0) ? CPUTIME_NICE : CPUTIME_USER; |
9387 |
++ index = task_running_nice(p) ? CPUTIME_NICE : CPUTIME_USER; |
9388 |
+ |
9389 |
+ /* Add user time to cpustat. */ |
9390 |
+ task_group_account_field(p, index, cputime); |
9391 |
+@@ -146,7 +146,7 @@ void account_guest_time(struct task_struct *p, u64 cputime) |
9392 |
+ p->gtime += cputime; |
9393 |
+ |
9394 |
+ /* Add guest time to cpustat. */ |
9395 |
+- if (task_nice(p) > 0) { |
9396 |
++ if (task_running_nice(p)) { |
9397 |
+ task_group_account_field(p, CPUTIME_NICE, cputime); |
9398 |
+ cpustat[CPUTIME_GUEST_NICE] += cputime; |
9399 |
+ } else { |
9400 |
+@@ -269,7 +269,7 @@ static inline u64 account_other_time(u64 max) |
9401 |
+ #ifdef CONFIG_64BIT |
9402 |
+ static inline u64 read_sum_exec_runtime(struct task_struct *t) |
9403 |
+ { |
9404 |
+- return t->se.sum_exec_runtime; |
9405 |
++ return tsk_seruntime(t); |
9406 |
+ } |
9407 |
+ #else |
9408 |
+ static u64 read_sum_exec_runtime(struct task_struct *t) |
9409 |
+@@ -279,7 +279,7 @@ static u64 read_sum_exec_runtime(struct task_struct *t) |
9410 |
+ struct rq *rq; |
9411 |
+ |
9412 |
+ rq = task_rq_lock(t, &rf); |
9413 |
+- ns = t->se.sum_exec_runtime; |
9414 |
++ ns = tsk_seruntime(t); |
9415 |
+ task_rq_unlock(rq, t, &rf); |
9416 |
+ |
9417 |
+ return ns; |
9418 |
+@@ -611,7 +611,7 @@ void cputime_adjust(struct task_cputime *curr, struct prev_cputime *prev, |
9419 |
+ void task_cputime_adjusted(struct task_struct *p, u64 *ut, u64 *st) |
9420 |
+ { |
9421 |
+ struct task_cputime cputime = { |
9422 |
+- .sum_exec_runtime = p->se.sum_exec_runtime, |
9423 |
++ .sum_exec_runtime = tsk_seruntime(p), |
9424 |
+ }; |
9425 |
+ |
9426 |
+ if (task_cputime(p, &cputime.utime, &cputime.stime)) |
9427 |
+diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c |
9428 |
+index bb3d63bdf4ae..4e1680785704 100644 |
9429 |
+--- a/kernel/sched/debug.c |
9430 |
++++ b/kernel/sched/debug.c |
9431 |
+@@ -7,6 +7,7 @@ |
9432 |
+ * Copyright(C) 2007, Red Hat, Inc., Ingo Molnar |
9433 |
+ */ |
9434 |
+ |
9435 |
++#ifndef CONFIG_SCHED_ALT |
9436 |
+ /* |
9437 |
+ * This allows printing both to /proc/sched_debug and |
9438 |
+ * to the console |
9439 |
+@@ -215,6 +216,7 @@ static const struct file_operations sched_scaling_fops = { |
9440 |
+ }; |
9441 |
+ |
9442 |
+ #endif /* SMP */ |
9443 |
++#endif /* !CONFIG_SCHED_ALT */ |
9444 |
+ |
9445 |
+ #ifdef CONFIG_PREEMPT_DYNAMIC |
9446 |
+ |
9447 |
+@@ -278,6 +280,7 @@ static const struct file_operations sched_dynamic_fops = { |
9448 |
+ |
9449 |
+ #endif /* CONFIG_PREEMPT_DYNAMIC */ |
9450 |
+ |
9451 |
++#ifndef CONFIG_SCHED_ALT |
9452 |
+ __read_mostly bool sched_debug_verbose; |
9453 |
+ |
9454 |
+ static const struct seq_operations sched_debug_sops; |
9455 |
+@@ -293,6 +296,7 @@ static const struct file_operations sched_debug_fops = { |
9456 |
+ .llseek = seq_lseek, |
9457 |
+ .release = seq_release, |
9458 |
+ }; |
9459 |
++#endif /* !CONFIG_SCHED_ALT */ |
9460 |
+ |
9461 |
+ static struct dentry *debugfs_sched; |
9462 |
+ |
9463 |
+@@ -302,12 +306,15 @@ static __init int sched_init_debug(void) |
9464 |
+ |
9465 |
+ debugfs_sched = debugfs_create_dir("sched", NULL); |
9466 |
+ |
9467 |
++#ifndef CONFIG_SCHED_ALT |
9468 |
+ debugfs_create_file("features", 0644, debugfs_sched, NULL, &sched_feat_fops); |
9469 |
+ debugfs_create_bool("verbose", 0644, debugfs_sched, &sched_debug_verbose); |
9470 |
++#endif /* !CONFIG_SCHED_ALT */ |
9471 |
+ #ifdef CONFIG_PREEMPT_DYNAMIC |
9472 |
+ debugfs_create_file("preempt", 0644, debugfs_sched, NULL, &sched_dynamic_fops); |
9473 |
+ #endif |
9474 |
+ |
9475 |
++#ifndef CONFIG_SCHED_ALT |
9476 |
+ debugfs_create_u32("latency_ns", 0644, debugfs_sched, &sysctl_sched_latency); |
9477 |
+ debugfs_create_u32("min_granularity_ns", 0644, debugfs_sched, &sysctl_sched_min_granularity); |
9478 |
+ debugfs_create_u32("idle_min_granularity_ns", 0644, debugfs_sched, &sysctl_sched_idle_min_granularity); |
9479 |
+@@ -336,11 +343,13 @@ static __init int sched_init_debug(void) |
9480 |
+ #endif |
9481 |
+ |
9482 |
+ debugfs_create_file("debug", 0444, debugfs_sched, NULL, &sched_debug_fops); |
9483 |
++#endif /* !CONFIG_SCHED_ALT */ |
9484 |
+ |
9485 |
+ return 0; |
9486 |
+ } |
9487 |
+ late_initcall(sched_init_debug); |
9488 |
+ |
9489 |
++#ifndef CONFIG_SCHED_ALT |
9490 |
+ #ifdef CONFIG_SMP |
9491 |
+ |
9492 |
+ static cpumask_var_t sd_sysctl_cpus; |
9493 |
+@@ -1067,6 +1076,7 @@ void proc_sched_set_task(struct task_struct *p) |
9494 |
+ memset(&p->stats, 0, sizeof(p->stats)); |
9495 |
+ #endif |
9496 |
+ } |
9497 |
++#endif /* !CONFIG_SCHED_ALT */ |
9498 |
+ |
9499 |
+ void resched_latency_warn(int cpu, u64 latency) |
9500 |
+ { |
9501 |
+diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c |
9502 |
+index 328cccbee444..aef991facc79 100644 |
9503 |
+--- a/kernel/sched/idle.c |
9504 |
++++ b/kernel/sched/idle.c |
9505 |
+@@ -400,6 +400,7 @@ void cpu_startup_entry(enum cpuhp_state state) |
9506 |
+ do_idle(); |
9507 |
+ } |
9508 |
+ |
9509 |
++#ifndef CONFIG_SCHED_ALT |
9510 |
+ /* |
9511 |
+ * idle-task scheduling class. |
9512 |
+ */ |
9513 |
+@@ -521,3 +522,4 @@ DEFINE_SCHED_CLASS(idle) = { |
9514 |
+ .switched_to = switched_to_idle, |
9515 |
+ .update_curr = update_curr_idle, |
9516 |
+ }; |
9517 |
++#endif |
9518 |
+diff --git a/kernel/sched/pds.h b/kernel/sched/pds.h |
9519 |
+new file mode 100644 |
9520 |
+index 000000000000..56a649d02e49 |
9521 |
+--- /dev/null |
9522 |
++++ b/kernel/sched/pds.h |
9523 |
+@@ -0,0 +1,127 @@ |
9524 |
++#define ALT_SCHED_VERSION_MSG "sched/pds: PDS CPU Scheduler "ALT_SCHED_VERSION" by Alfred Chen.\n" |
9525 |
++ |
9526 |
++static int sched_timeslice_shift = 22; |
9527 |
++ |
9528 |
++#define NORMAL_PRIO_MOD(x) ((x) & (NORMAL_PRIO_NUM - 1)) |
9529 |
++ |
9530 |
++/* |
9531 |
++ * Common interfaces |
9532 |
++ */ |
9533 |
++static inline void sched_timeslice_imp(const int timeslice_ms) |
9534 |
++{ |
9535 |
++ if (2 == timeslice_ms) |
9536 |
++ sched_timeslice_shift = 21; |
9537 |
++} |
9538 |
++ |
9539 |
++static inline int |
9540 |
++task_sched_prio_normal(const struct task_struct *p, const struct rq *rq) |
9541 |
++{ |
9542 |
++ s64 delta = p->deadline - rq->time_edge + NORMAL_PRIO_NUM - NICE_WIDTH; |
9543 |
++ |
9544 |
++ if (WARN_ONCE(delta > NORMAL_PRIO_NUM - 1, |
9545 |
++ "pds: task_sched_prio_normal() delta %lld\n", delta)) |
9546 |
++ return NORMAL_PRIO_NUM - 1; |
9547 |
++ |
9548 |
++ return (delta < 0) ? 0 : delta; |
9549 |
++} |
9550 |
++ |
9551 |
++static inline int task_sched_prio(const struct task_struct *p) |
9552 |
++{ |
9553 |
++ return (p->prio < MAX_RT_PRIO) ? p->prio : |
9554 |
++ MIN_NORMAL_PRIO + task_sched_prio_normal(p, task_rq(p)); |
9555 |
++} |
9556 |
++ |
9557 |
++static inline int |
9558 |
++task_sched_prio_idx(const struct task_struct *p, const struct rq *rq) |
9559 |
++{ |
9560 |
++ return (p->prio < MAX_RT_PRIO) ? p->prio : MIN_NORMAL_PRIO + |
9561 |
++ NORMAL_PRIO_MOD(task_sched_prio_normal(p, rq) + rq->time_edge); |
9562 |
++} |
9563 |
++ |
9564 |
++static inline int sched_prio2idx(int prio, struct rq *rq) |
9565 |
++{ |
9566 |
++ return (IDLE_TASK_SCHED_PRIO == prio || prio < MAX_RT_PRIO) ? prio : |
9567 |
++ MIN_NORMAL_PRIO + NORMAL_PRIO_MOD((prio - MIN_NORMAL_PRIO) + |
9568 |
++ rq->time_edge); |
9569 |
++} |
9570 |
++ |
9571 |
++static inline int sched_idx2prio(int idx, struct rq *rq) |
9572 |
++{ |
9573 |
++ return (idx < MAX_RT_PRIO) ? idx : MIN_NORMAL_PRIO + |
9574 |
++ NORMAL_PRIO_MOD((idx - MIN_NORMAL_PRIO) + NORMAL_PRIO_NUM - |
9575 |
++ NORMAL_PRIO_MOD(rq->time_edge)); |
9576 |
++} |
9577 |
++ |
9578 |
++static inline void sched_renew_deadline(struct task_struct *p, const struct rq *rq) |
9579 |
++{ |
9580 |
++ if (p->prio >= MAX_RT_PRIO) |
9581 |
++ p->deadline = (rq->clock >> sched_timeslice_shift) + |
9582 |
++ p->static_prio - (MAX_PRIO - NICE_WIDTH); |
9583 |
++} |
9584 |
++ |
9585 |
++int task_running_nice(struct task_struct *p) |
9586 |
++{ |
9587 |
++ return (p->prio > DEFAULT_PRIO); |
9588 |
++} |
9589 |
++ |
9590 |
++static inline void update_rq_time_edge(struct rq *rq) |
9591 |
++{ |
9592 |
++ struct list_head head; |
9593 |
++ u64 old = rq->time_edge; |
9594 |
++ u64 now = rq->clock >> sched_timeslice_shift; |
9595 |
++ u64 prio, delta; |
9596 |
++ |
9597 |
++ if (now == old) |
9598 |
++ return; |
9599 |
++ |
9600 |
++ delta = min_t(u64, NORMAL_PRIO_NUM, now - old); |
9601 |
++ INIT_LIST_HEAD(&head); |
9602 |
++ |
9603 |
++ for_each_set_bit(prio, &rq->queue.bitmap[2], delta) |
9604 |
++ list_splice_tail_init(rq->queue.heads + MIN_NORMAL_PRIO + |
9605 |
++ NORMAL_PRIO_MOD(prio + old), &head); |
9606 |
++ |
9607 |
++ rq->queue.bitmap[2] = (NORMAL_PRIO_NUM == delta) ? 0UL : |
9608 |
++ rq->queue.bitmap[2] >> delta; |
9609 |
++ rq->time_edge = now; |
9610 |
++ if (!list_empty(&head)) { |
9611 |
++ u64 idx = MIN_NORMAL_PRIO + NORMAL_PRIO_MOD(now); |
9612 |
++ struct task_struct *p; |
9613 |
++ |
9614 |
++ list_for_each_entry(p, &head, sq_node) |
9615 |
++ p->sq_idx = idx; |
9616 |
++ |
9617 |
++ list_splice(&head, rq->queue.heads + idx); |
9618 |
++ rq->queue.bitmap[2] |= 1UL; |
9619 |
++ } |
9620 |
++} |
9621 |
++ |
9622 |
++static inline void time_slice_expired(struct task_struct *p, struct rq *rq) |
9623 |
++{ |
9624 |
++ p->time_slice = sched_timeslice_ns; |
9625 |
++ sched_renew_deadline(p, rq); |
9626 |
++ if (SCHED_FIFO != p->policy && task_on_rq_queued(p)) |
9627 |
++ requeue_task(p, rq, task_sched_prio_idx(p, rq)); |
9628 |
++} |
9629 |
++ |
9630 |
++static inline void sched_task_sanity_check(struct task_struct *p, struct rq *rq) |
9631 |
++{ |
9632 |
++ u64 max_dl = rq->time_edge + NICE_WIDTH - 1; |
9633 |
++ if (unlikely(p->deadline > max_dl)) |
9634 |
++ p->deadline = max_dl; |
9635 |
++} |
9636 |
++ |
9637 |
++static void sched_task_fork(struct task_struct *p, struct rq *rq) |
9638 |
++{ |
9639 |
++ sched_renew_deadline(p, rq); |
9640 |
++} |
9641 |
++ |
9642 |
++static inline void do_sched_yield_type_1(struct task_struct *p, struct rq *rq) |
9643 |
++{ |
9644 |
++ time_slice_expired(p, rq); |
9645 |
++} |
9646 |
++ |
9647 |
++#ifdef CONFIG_SMP |
9648 |
++static inline void sched_task_ttwu(struct task_struct *p) {} |
9649 |
++#endif |
9650 |
++static inline void sched_task_deactivate(struct task_struct *p, struct rq *rq) {} |
9651 |
+diff --git a/kernel/sched/pelt.c b/kernel/sched/pelt.c |
9652 |
+index 0f310768260c..bd38bf738fe9 100644 |
9653 |
+--- a/kernel/sched/pelt.c |
9654 |
++++ b/kernel/sched/pelt.c |
9655 |
+@@ -266,6 +266,7 @@ ___update_load_avg(struct sched_avg *sa, unsigned long load) |
9656 |
+ WRITE_ONCE(sa->util_avg, sa->util_sum / divider); |
9657 |
+ } |
9658 |
+ |
9659 |
++#ifndef CONFIG_SCHED_ALT |
9660 |
+ /* |
9661 |
+ * sched_entity: |
9662 |
+ * |
9663 |
+@@ -383,8 +384,9 @@ int update_dl_rq_load_avg(u64 now, struct rq *rq, int running) |
9664 |
+ |
9665 |
+ return 0; |
9666 |
+ } |
9667 |
++#endif |
9668 |
+ |
9669 |
+-#ifdef CONFIG_SCHED_THERMAL_PRESSURE |
9670 |
++#if defined(CONFIG_SCHED_THERMAL_PRESSURE) && !defined(CONFIG_SCHED_ALT) |
9671 |
+ /* |
9672 |
+ * thermal: |
9673 |
+ * |
9674 |
+diff --git a/kernel/sched/pelt.h b/kernel/sched/pelt.h |
9675 |
+index 4ff2ed4f8fa1..226eeed61318 100644 |
9676 |
+--- a/kernel/sched/pelt.h |
9677 |
++++ b/kernel/sched/pelt.h |
9678 |
+@@ -1,13 +1,15 @@ |
9679 |
+ #ifdef CONFIG_SMP |
9680 |
+ #include "sched-pelt.h" |
9681 |
+ |
9682 |
++#ifndef CONFIG_SCHED_ALT |
9683 |
+ int __update_load_avg_blocked_se(u64 now, struct sched_entity *se); |
9684 |
+ int __update_load_avg_se(u64 now, struct cfs_rq *cfs_rq, struct sched_entity *se); |
9685 |
+ int __update_load_avg_cfs_rq(u64 now, struct cfs_rq *cfs_rq); |
9686 |
+ int update_rt_rq_load_avg(u64 now, struct rq *rq, int running); |
9687 |
+ int update_dl_rq_load_avg(u64 now, struct rq *rq, int running); |
9688 |
++#endif |
9689 |
+ |
9690 |
+-#ifdef CONFIG_SCHED_THERMAL_PRESSURE |
9691 |
++#if defined(CONFIG_SCHED_THERMAL_PRESSURE) && !defined(CONFIG_SCHED_ALT) |
9692 |
+ int update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity); |
9693 |
+ |
9694 |
+ static inline u64 thermal_load_avg(struct rq *rq) |
9695 |
+@@ -44,6 +46,7 @@ static inline u32 get_pelt_divider(struct sched_avg *avg) |
9696 |
+ return PELT_MIN_DIVIDER + avg->period_contrib; |
9697 |
+ } |
9698 |
+ |
9699 |
++#ifndef CONFIG_SCHED_ALT |
9700 |
+ static inline void cfs_se_util_change(struct sched_avg *avg) |
9701 |
+ { |
9702 |
+ unsigned int enqueued; |
9703 |
+@@ -155,9 +158,11 @@ static inline u64 cfs_rq_clock_pelt(struct cfs_rq *cfs_rq) |
9704 |
+ return rq_clock_pelt(rq_of(cfs_rq)); |
9705 |
+ } |
9706 |
+ #endif |
9707 |
++#endif /* CONFIG_SCHED_ALT */ |
9708 |
+ |
9709 |
+ #else |
9710 |
+ |
9711 |
++#ifndef CONFIG_SCHED_ALT |
9712 |
+ static inline int |
9713 |
+ update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq) |
9714 |
+ { |
9715 |
+@@ -175,6 +180,7 @@ update_dl_rq_load_avg(u64 now, struct rq *rq, int running) |
9716 |
+ { |
9717 |
+ return 0; |
9718 |
+ } |
9719 |
++#endif |
9720 |
+ |
9721 |
+ static inline int |
9722 |
+ update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity) |
9723 |
+diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h |
9724 |
+index 47b89a0fc6e5..de2641a32c22 100644 |
9725 |
+--- a/kernel/sched/sched.h |
9726 |
++++ b/kernel/sched/sched.h |
9727 |
+@@ -5,6 +5,10 @@ |
9728 |
+ #ifndef _KERNEL_SCHED_SCHED_H |
9729 |
+ #define _KERNEL_SCHED_SCHED_H |
9730 |
+ |
9731 |
++#ifdef CONFIG_SCHED_ALT |
9732 |
++#include "alt_sched.h" |
9733 |
++#else |
9734 |
++ |
9735 |
+ #include <linux/sched/affinity.h> |
9736 |
+ #include <linux/sched/autogroup.h> |
9737 |
+ #include <linux/sched/cpufreq.h> |
9738 |
+@@ -3116,4 +3120,9 @@ extern int sched_dynamic_mode(const char *str); |
9739 |
+ extern void sched_dynamic_update(int mode); |
9740 |
+ #endif |
9741 |
+ |
9742 |
++static inline int task_running_nice(struct task_struct *p) |
9743 |
++{ |
9744 |
++ return (task_nice(p) > 0); |
9745 |
++} |
9746 |
++#endif /* !CONFIG_SCHED_ALT */ |
9747 |
+ #endif /* _KERNEL_SCHED_SCHED_H */ |
9748 |
+diff --git a/kernel/sched/stats.c b/kernel/sched/stats.c |
9749 |
+index 857f837f52cb..5486c63e4790 100644 |
9750 |
+--- a/kernel/sched/stats.c |
9751 |
++++ b/kernel/sched/stats.c |
9752 |
+@@ -125,8 +125,10 @@ static int show_schedstat(struct seq_file *seq, void *v) |
9753 |
+ } else { |
9754 |
+ struct rq *rq; |
9755 |
+ #ifdef CONFIG_SMP |
9756 |
++#ifndef CONFIG_SCHED_ALT |
9757 |
+ struct sched_domain *sd; |
9758 |
+ int dcount = 0; |
9759 |
++#endif |
9760 |
+ #endif |
9761 |
+ cpu = (unsigned long)(v - 2); |
9762 |
+ rq = cpu_rq(cpu); |
9763 |
+@@ -143,6 +145,7 @@ static int show_schedstat(struct seq_file *seq, void *v) |
9764 |
+ seq_printf(seq, "\n"); |
9765 |
+ |
9766 |
+ #ifdef CONFIG_SMP |
9767 |
++#ifndef CONFIG_SCHED_ALT |
9768 |
+ /* domain-specific stats */ |
9769 |
+ rcu_read_lock(); |
9770 |
+ for_each_domain(cpu, sd) { |
9771 |
+@@ -171,6 +174,7 @@ static int show_schedstat(struct seq_file *seq, void *v) |
9772 |
+ sd->ttwu_move_balance); |
9773 |
+ } |
9774 |
+ rcu_read_unlock(); |
9775 |
++#endif |
9776 |
+ #endif |
9777 |
+ } |
9778 |
+ return 0; |
9779 |
+diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h |
9780 |
+index baa839c1ba96..15238be0581b 100644 |
9781 |
+--- a/kernel/sched/stats.h |
9782 |
++++ b/kernel/sched/stats.h |
9783 |
+@@ -89,6 +89,7 @@ static inline void rq_sched_info_depart (struct rq *rq, unsigned long long delt |
9784 |
+ |
9785 |
+ #endif /* CONFIG_SCHEDSTATS */ |
9786 |
+ |
9787 |
++#ifndef CONFIG_SCHED_ALT |
9788 |
+ #ifdef CONFIG_FAIR_GROUP_SCHED |
9789 |
+ struct sched_entity_stats { |
9790 |
+ struct sched_entity se; |
9791 |
+@@ -105,6 +106,7 @@ __schedstats_from_se(struct sched_entity *se) |
9792 |
+ #endif |
9793 |
+ return &task_of(se)->stats; |
9794 |
+ } |
9795 |
++#endif /* CONFIG_SCHED_ALT */ |
9796 |
+ |
9797 |
+ #ifdef CONFIG_PSI |
9798 |
+ /* |
9799 |
+diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c |
9800 |
+index 05b6c2ad90b9..480ef393b3c9 100644 |
9801 |
+--- a/kernel/sched/topology.c |
9802 |
++++ b/kernel/sched/topology.c |
9803 |
+@@ -3,6 +3,7 @@ |
9804 |
+ * Scheduler topology setup/handling methods |
9805 |
+ */ |
9806 |
+ |
9807 |
++#ifndef CONFIG_SCHED_ALT |
9808 |
+ DEFINE_MUTEX(sched_domains_mutex); |
9809 |
+ |
9810 |
+ /* Protected by sched_domains_mutex: */ |
9811 |
+@@ -1413,8 +1414,10 @@ static void asym_cpu_capacity_scan(void) |
9812 |
+ */ |
9813 |
+ |
9814 |
+ static int default_relax_domain_level = -1; |
9815 |
++#endif /* CONFIG_SCHED_ALT */ |
9816 |
+ int sched_domain_level_max; |
9817 |
+ |
9818 |
++#ifndef CONFIG_SCHED_ALT |
9819 |
+ static int __init setup_relax_domain_level(char *str) |
9820 |
+ { |
9821 |
+ if (kstrtoint(str, 0, &default_relax_domain_level)) |
9822 |
+@@ -1647,6 +1650,7 @@ sd_init(struct sched_domain_topology_level *tl, |
9823 |
+ |
9824 |
+ return sd; |
9825 |
+ } |
9826 |
++#endif /* CONFIG_SCHED_ALT */ |
9827 |
+ |
9828 |
+ /* |
9829 |
+ * Topology list, bottom-up. |
9830 |
+@@ -1683,6 +1687,7 @@ void set_sched_topology(struct sched_domain_topology_level *tl) |
9831 |
+ sched_domain_topology_saved = NULL; |
9832 |
+ } |
9833 |
+ |
9834 |
++#ifndef CONFIG_SCHED_ALT |
9835 |
+ #ifdef CONFIG_NUMA |
9836 |
+ |
9837 |
+ static const struct cpumask *sd_numa_mask(int cpu) |
9838 |
+@@ -2638,3 +2643,15 @@ void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], |
9839 |
+ partition_sched_domains_locked(ndoms_new, doms_new, dattr_new); |
9840 |
+ mutex_unlock(&sched_domains_mutex); |
9841 |
+ } |
9842 |
++#else /* CONFIG_SCHED_ALT */ |
9843 |
++void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], |
9844 |
++ struct sched_domain_attr *dattr_new) |
9845 |
++{} |
9846 |
++ |
9847 |
++#ifdef CONFIG_NUMA |
9848 |
++int sched_numa_find_closest(const struct cpumask *cpus, int cpu) |
9849 |
++{ |
9850 |
++ return best_mask_cpu(cpu, cpus); |
9851 |
++} |
9852 |
++#endif /* CONFIG_NUMA */ |
9853 |
++#endif |
9854 |
+diff --git a/kernel/sysctl.c b/kernel/sysctl.c |
9855 |
+index 35d034219513..23719c728677 100644 |
9856 |
+--- a/kernel/sysctl.c |
9857 |
++++ b/kernel/sysctl.c |
9858 |
+@@ -86,6 +86,10 @@ |
9859 |
+ |
9860 |
+ /* Constants used for minimum and maximum */ |
9861 |
+ |
9862 |
++#ifdef CONFIG_SCHED_ALT |
9863 |
++extern int sched_yield_type; |
9864 |
++#endif |
9865 |
++ |
9866 |
+ #ifdef CONFIG_PERF_EVENTS |
9867 |
+ static const int six_hundred_forty_kb = 640 * 1024; |
9868 |
+ #endif |
9869 |
+@@ -1590,6 +1594,7 @@ int proc_do_static_key(struct ctl_table *table, int write, |
9870 |
+ } |
9871 |
+ |
9872 |
+ static struct ctl_table kern_table[] = { |
9873 |
++#ifndef CONFIG_SCHED_ALT |
9874 |
+ #ifdef CONFIG_NUMA_BALANCING |
9875 |
+ { |
9876 |
+ .procname = "numa_balancing", |
9877 |
+@@ -1601,6 +1606,7 @@ static struct ctl_table kern_table[] = { |
9878 |
+ .extra2 = SYSCTL_FOUR, |
9879 |
+ }, |
9880 |
+ #endif /* CONFIG_NUMA_BALANCING */ |
9881 |
++#endif /* !CONFIG_SCHED_ALT */ |
9882 |
+ { |
9883 |
+ .procname = "panic", |
9884 |
+ .data = &panic_timeout, |
9885 |
+@@ -1902,6 +1908,17 @@ static struct ctl_table kern_table[] = { |
9886 |
+ .proc_handler = proc_dointvec, |
9887 |
+ }, |
9888 |
+ #endif |
9889 |
++#ifdef CONFIG_SCHED_ALT |
9890 |
++ { |
9891 |
++ .procname = "yield_type", |
9892 |
++ .data = &sched_yield_type, |
9893 |
++ .maxlen = sizeof (int), |
9894 |
++ .mode = 0644, |
9895 |
++ .proc_handler = &proc_dointvec_minmax, |
9896 |
++ .extra1 = SYSCTL_ZERO, |
9897 |
++ .extra2 = SYSCTL_TWO, |
9898 |
++ }, |
9899 |
++#endif |
9900 |
+ #if defined(CONFIG_S390) && defined(CONFIG_SMP) |
9901 |
+ { |
9902 |
+ .procname = "spin_retry", |
9903 |
+diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c |
9904 |
+index 0ea8702eb516..a27a0f3a654d 100644 |
9905 |
+--- a/kernel/time/hrtimer.c |
9906 |
++++ b/kernel/time/hrtimer.c |
9907 |
+@@ -2088,8 +2088,10 @@ long hrtimer_nanosleep(ktime_t rqtp, const enum hrtimer_mode mode, |
9908 |
+ int ret = 0; |
9909 |
+ u64 slack; |
9910 |
+ |
9911 |
++#ifndef CONFIG_SCHED_ALT |
9912 |
+ slack = current->timer_slack_ns; |
9913 |
+ if (dl_task(current) || rt_task(current)) |
9914 |
++#endif |
9915 |
+ slack = 0; |
9916 |
+ |
9917 |
+ hrtimer_init_sleeper_on_stack(&t, clockid, mode); |
9918 |
+diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c |
9919 |
+index cb925e8ef9a8..67d823510f5c 100644 |
9920 |
+--- a/kernel/time/posix-cpu-timers.c |
9921 |
++++ b/kernel/time/posix-cpu-timers.c |
9922 |
+@@ -223,7 +223,7 @@ static void task_sample_cputime(struct task_struct *p, u64 *samples) |
9923 |
+ u64 stime, utime; |
9924 |
+ |
9925 |
+ task_cputime(p, &utime, &stime); |
9926 |
+- store_samples(samples, stime, utime, p->se.sum_exec_runtime); |
9927 |
++ store_samples(samples, stime, utime, tsk_seruntime(p)); |
9928 |
+ } |
9929 |
+ |
9930 |
+ static void proc_sample_cputime_atomic(struct task_cputime_atomic *at, |
9931 |
+@@ -866,6 +866,7 @@ static void collect_posix_cputimers(struct posix_cputimers *pct, u64 *samples, |
9932 |
+ } |
9933 |
+ } |
9934 |
+ |
9935 |
++#ifndef CONFIG_SCHED_ALT |
9936 |
+ static inline void check_dl_overrun(struct task_struct *tsk) |
9937 |
+ { |
9938 |
+ if (tsk->dl.dl_overrun) { |
9939 |
+@@ -873,6 +874,7 @@ static inline void check_dl_overrun(struct task_struct *tsk) |
9940 |
+ send_signal_locked(SIGXCPU, SEND_SIG_PRIV, tsk, PIDTYPE_TGID); |
9941 |
+ } |
9942 |
+ } |
9943 |
++#endif |
9944 |
+ |
9945 |
+ static bool check_rlimit(u64 time, u64 limit, int signo, bool rt, bool hard) |
9946 |
+ { |
9947 |
+@@ -900,8 +902,10 @@ static void check_thread_timers(struct task_struct *tsk, |
9948 |
+ u64 samples[CPUCLOCK_MAX]; |
9949 |
+ unsigned long soft; |
9950 |
+ |
9951 |
++#ifndef CONFIG_SCHED_ALT |
9952 |
+ if (dl_task(tsk)) |
9953 |
+ check_dl_overrun(tsk); |
9954 |
++#endif |
9955 |
+ |
9956 |
+ if (expiry_cache_is_inactive(pct)) |
9957 |
+ return; |
9958 |
+@@ -915,7 +919,7 @@ static void check_thread_timers(struct task_struct *tsk, |
9959 |
+ soft = task_rlimit(tsk, RLIMIT_RTTIME); |
9960 |
+ if (soft != RLIM_INFINITY) { |
9961 |
+ /* Task RT timeout is accounted in jiffies. RTTIME is usec */ |
9962 |
+- unsigned long rttime = tsk->rt.timeout * (USEC_PER_SEC / HZ); |
9963 |
++ unsigned long rttime = tsk_rttimeout(tsk) * (USEC_PER_SEC / HZ); |
9964 |
+ unsigned long hard = task_rlimit_max(tsk, RLIMIT_RTTIME); |
9965 |
+ |
9966 |
+ /* At the hard limit, send SIGKILL. No further action. */ |
9967 |
+@@ -1151,8 +1155,10 @@ static inline bool fastpath_timer_check(struct task_struct *tsk) |
9968 |
+ return true; |
9969 |
+ } |
9970 |
+ |
9971 |
++#ifndef CONFIG_SCHED_ALT |
9972 |
+ if (dl_task(tsk) && tsk->dl.dl_overrun) |
9973 |
+ return true; |
9974 |
++#endif |
9975 |
+ |
9976 |
+ return false; |
9977 |
+ } |
9978 |
+diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c |
9979 |
+index a2d301f58ced..2ccdede8585c 100644 |
9980 |
+--- a/kernel/trace/trace_selftest.c |
9981 |
++++ b/kernel/trace/trace_selftest.c |
9982 |
+@@ -1143,10 +1143,15 @@ static int trace_wakeup_test_thread(void *data) |
9983 |
+ { |
9984 |
+ /* Make this a -deadline thread */ |
9985 |
+ static const struct sched_attr attr = { |
9986 |
++#ifdef CONFIG_SCHED_ALT |
9987 |
++ /* No deadline on BMQ/PDS, use RR */ |
9988 |
++ .sched_policy = SCHED_RR, |
9989 |
++#else |
9990 |
+ .sched_policy = SCHED_DEADLINE, |
9991 |
+ .sched_runtime = 100000ULL, |
9992 |
+ .sched_deadline = 10000000ULL, |
9993 |
+ .sched_period = 10000000ULL |
9994 |
++#endif |
9995 |
+ }; |
9996 |
+ struct wakeup_test_data *x = data; |
9997 |
+ |
9998 |
|
9999 |
diff --git a/5021_BMQ-and-PDS-gentoo-defaults.patch b/5021_BMQ-and-PDS-gentoo-defaults.patch |
10000 |
new file mode 100644 |
10001 |
index 00000000..6b2049da |
10002 |
--- /dev/null |
10003 |
+++ b/5021_BMQ-and-PDS-gentoo-defaults.patch |
10004 |
@@ -0,0 +1,13 @@ |
10005 |
+--- a/init/Kconfig 2022-07-07 13:22:00.698439887 -0400 |
10006 |
++++ b/init/Kconfig 2022-07-07 13:23:45.152333576 -0400 |
10007 |
+@@ -874,8 +874,9 @@ config UCLAMP_BUCKETS_COUNT |
10008 |
+ If in doubt, use the default value. |
10009 |
+ |
10010 |
+ menuconfig SCHED_ALT |
10011 |
++ depends on X86_64 |
10012 |
+ bool "Alternative CPU Schedulers" |
10013 |
+- default y |
10014 |
++ default n |
10015 |
+ help |
10016 |
+ This feature enable alternative CPU scheduler" |
10017 |
+ |