Re: [gentoo-user] New PC hangs/lacks ?

Hi Walter,

thanks for your input again.

A said previously: This is not a problem of a high load,
which needs to be handled. This is kinda temporary deadlock.
Even if I would choose the best possible scheduler...the
CPU would not get the chance to execute the code of the scheduler,
because something locks the system. This description is meant to
describe the situation more than to describe the exact technical
background, for which I still search a solution to avoid it completly.

In the moment everything runs fine again, without haveing changed
any kernel configuration or anything else actively. /Something/
must have changed, though.

Cheers!
Meino


On 05/06 02:23, Walter Dnes wrote:
>   You can make some tradeoffs with kernel options.  Which one you
> choose is up to you (assuming it's your personal machine).  In
> "make menuconfig" go to...
>
> General setup  -->
>     Preemption Model --->
>
>   You have 3 choices.  The 1st choice will probably finish your
> rendering fastest, but other programs will have problems breaking in for
> a timeslice.  This will look like freezing.  The 3rd choice will give
> the most possibility for other programs to preempt, but will run
> slightly slower overall.  The 2nd choice is a compromise.  Assuming
> you're the admin of the machine, the choice is up to you.  Sorry, "you
> can't have your cake and eat it too".
>
> 1) "No Forced Preemption (Server)"; manual version "CONFIG_PREEMPT_NONE"
>
> > This is the traditional Linux preemption model, geared towards
> > throughput. It will still provide good latencies most of the time,
> > but there are no guarantees and occasional longer delays are possible.
> >
> > Select this option if you are building a kernel for a server or
> > scientific/computation system, or if you want to maximize the raw
> > processing power of the kernel, irrespective of scheduling latencies.
>
> 2) "Voluntary Kernel Preemption (Desktop)"; "CONFIG_PREEMPT_VOLUNTARY"
>
> > This option reduces the latency of the kernel by adding more
> > "explicit preemption points" to the kernel code. These new
> > preemption points have been selected to reduce the maximum latency
> > of rescheduling, providing faster application reactions, at the
> > cost of slightly lower throughput.
> >
> > This allows reaction to interactive events by allowing a low
> > priority process to voluntarily preempt itself even if it is in
> > kernel mode executing a system call. This allows applications to
> > run more 'smoothly' even when the system is under load.
>
> 3) "Preemptible Kernel (Low-Latency Desktop)"; "CONFIG_PREEMPT"
>
> > This option reduces the latency of the kernel by making all kernel
> > code (that is not executing in a critical section) preemptible.
> > This allows reaction to interactive events by permitting a low
> > priority process to be preempted involuntarily even if it is in kernel
> > mode executing a system call and would otherwise not be about to reach
> > a natural preemption point.  This allows applications to run more
> > 'smoothly' even when the system is under load, at the cost of slightly
> > lower throughput and a slight runtime overhead to kernel code.
>
> --
> Walter Dnes <waltdnes@××××××××.org>
> I don't run "desktop environments"; I run useful applications
>