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Hey Mark, |
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|
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/usr/src/linux/init/Kconfig and kernel/Kconfig.preempt are the droids you |
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are looking for... |
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|
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config PREEMPT_RCU |
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def_bool TREE_PREEMPT_RCU |
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help |
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This option enables preemptible-RCU code that is common between |
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the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations. |
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|
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So you would want to /not/ pick one of those - however - looking further |
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|
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choice |
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prompt "RCU Implementation" |
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default TREE_RCU |
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|
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config TREE_RCU |
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bool "Tree-based hierarchical RCU" |
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depends on !PREEMPT && SMP |
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select IRQ_WORK |
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help |
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This option selects the RCU implementation that is |
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designed for very large SMP system with hundreds or |
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thousands of CPUs. It also scales down nicely to |
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smaller systems. |
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|
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config TREE_PREEMPT_RCU |
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bool "Preemptible tree-based hierarchical RCU" |
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depends on PREEMPT |
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select IRQ_WORK |
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help |
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This option selects the RCU implementation that is |
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designed for very large SMP systems with hundreds or |
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thousands of CPUs, but for which real-time response |
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is also required. It also scales down nicely to |
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smaller systems. |
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|
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Select this option if you are unsure. |
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|
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config TINY_RCU |
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bool "UP-only small-memory-footprint RCU" |
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depends on !PREEMPT && !SMP |
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help |
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This option selects the RCU implementation that is |
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designed for UP systems from which real-time response |
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is not required. This option greatly reduces the |
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memory footprint of RCU. |
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|
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endchoice |
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|
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Seems you would want TREE_RCU (or TINY_RCU if you really have a UP system) |
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- but both of those depend on !PREEMPT... which is counter to what you were |
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asked. |
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|
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In short - at least in 3.12.0 - I don't think what you've been asked for is |
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in fact possible - or I'm reading Kconfig wrongly (it's been a while) |
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|
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Cheers, |
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malc. |
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|
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|
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On Fri, Nov 22, 2013 at 7:40 PM, Mark Knecht <markknecht@×××××.com> wrote: |
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|
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> On Fri, Nov 22, 2013 at 11:21 AM, Volker Armin Hemmann |
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> <volkerarmin@××××××××××.com> wrote: |
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> <SNIP> |
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> >> which doesn't give me any option to change it in make menuconfig. |
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> > no, that means it is turned on by some other option. |
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> > |
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> > maybe you should use grep. |
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> |
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> Geez... |
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> |
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> |
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