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Date: Thu, 10 Sep 2009 09:33:37 -0700
Message-ID: <dda83e780909100933q28cd1e06kcbceec53d2c94936@mail.gmail.com>
Subject: Re: BFS vs. mainline scheduler benchmarks and measurements
From: Bret Towe <magnade@gmail.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
       Nikos Chantziaras <realnc@arcor.de>, Jens Axboe <jens.axboe@oracle.com>,
       Mike Galbraith <efault@gmx.de>, Con Kolivas <kernel@kolivas.org>,
       linux-kernel@vger.kernel.org
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On Thu, Sep 10, 2009 at 9:26 AM, Ingo Molnar <mingo@elte.hu> wrote:
>
> * Bret Towe <magnade@gmail.com> wrote:
>
>> On Thu, Sep 10, 2009 at 9:05 AM, Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:
>> > On Thu, 2009-09-10 at 09:02 -0700, Bret Towe wrote:
>> >>
>> >> thanks to this thread and others I've seen several kernel tunables
>> >> that can effect how the scheduler performs/acts
>> >> but what I don't see after a bit of looking is where all these are
>> >> documented
>> >> perhaps thats also part of the reason there are unhappy people with
>> >> the current code in the kernel just because they don't know how
>> >> to tune it for their workload
>> >
>> > The thing is, ideally they should not need to poke at these.
>> > These knobs are under CONFIG_SCHED_DEBUG, and that is exactly
>> > what they are for.
>>
>> even then I would think they should be documented so people can
>> find out what item is hurting their workload so they can better
>> report the bug no?
>
> Would be happy to apply such documentation patches. You could also
> help start adding a 'scheduler performance' wiki portion to
> perf.wiki.kernel.org, if you have time for that.

time isn't so much the issue but not having any clue as to what any
of the options do