Re: INGO Why you remove set_user_nice() from kernel/kthread.c

From: Chris Friesen
Date: Mon Sep 14 2009 - 11:13:55 EST


On 09/14/2009 08:05 AM, Mike Galbraith wrote:
> If you're asking Ingo a question, maybe a CC is in order.
>
> On Mon, 2009-09-14 at 17:42 +0400, Pavel Vasilyev wrote:
>>
>> Next patÑh -
>> http://www.kernel.org/diff/diffview.cgi?file=%2Fpub%2Flinux%2Fkernel%2F%2Fv2.6%2Fsnapshots%2Fpatch-2.6.31-git2.bz2;z=548
>>
>> This patch defines the core processes that are working with nice leve equal to
>> zero , as in the BFS. :)
>>
>> Why?
>
> I did that, not Ingo, and did so because with kthreads that use
> diddly-spit CPU (every one I see), it's just a waste of math. What
> kthreads are you seeing using so much CPU that their weight is a factor?
> They _should_ be able to preempt and get their work done just fine
> without a boost.

Under heavy network load ksoftirqd can use significant amounts of cpu.

Chris
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