From: Bodo Eggert <7eggert@gmx.de>
Subject: Re: sched_yield() on 2.6.25
To: Peter Zijlstra <a.p.zijlstra@chello.nl>,
       Jakub Jozwicki <jozwicki@aster.pl>, linux-kernel@vger.kernel.org,
       Robert Hancock <hancockr@shaw.ca>
Reply-To: 7eggert@gmx.de
Date: Wed, 11 Jun 2008 17:28:06 +0200
References: <aCBfw-3Cv-23@gated-at.bofh.it> <aCBfw-3Cv-21@gated-at.bofh.it> <aCJd6-3IF-11@gated-at.bofh.it> <aCRaM-8cM-33@gated-at.bofh.it>
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Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:
> On Mon, 2008-06-09 at 08:37 +0200, Jakub Jozwicki wrote:

>> From the man sched_yield:
>> 
>> A  process  can  relinquish  the  processor  voluntarily without blocking by
>> calling sched_yield().  The process will then be moved to the  end  of  the
>> queue  for  its static priority and a new process gets to run.
>> 
>> and also IEEE/Open Group:
>> http://www.opengroup.org/onlinepubs/000095399/functions/sched_yield.html
> 
> Yeah, except that is for Real-Time scheduling classes, SCHED_OTHER
> doesn't have static priority queues.
> 
> SCHED_OTHER doesn't have a specified implementation - so relying on it
> to do anything specific is well outside the scope of definition.

OTOH, it's sane not to schedule exactly the thread which just tried
to say "I can't do any sane work, please run another thread.

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