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From: Rik van Riel <riel@redhat.com>
To: Alex Shi <alex.shi@intel.com>
Cc: linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl,
	mingo@elte.hu, tim.c.chen@intel.com, shaohua.li@intel.com
Subject: Re: [PATCH] sched: recover sched_yield task running time increase
Date: Wed, 06 Apr 2011 01:07:30 -0400	[thread overview]
Message-ID: <4D9BF512.6080309@redhat.com> (raw)
In-Reply-To: <1302042823-23022-1-git-send-email-alex.shi@intel.com>

On 04/05/2011 06:33 PM, Alex Shi wrote:
> commit ac53db596cc08ecb8040c removed the sched_yield task running
> time increase, so the yielded task get more opportunity to be launch
> again. That may not the caller want to be. And this also causes
> volano benchmark drop 50~80 percent performance on core2/NHM/WSM
> machines. This patch recover the sched_yield task vruntime up.
>
> Signed-off-by: alex.shi@intel.com

NACK

This was switched off by default and under
the sysctl sched_compat_yield for a reason.

Reintroducing it under that sysctl option
may be acceptable, but by default it would
be doing the wrong thing for other workloads.

  reply	other threads:[~2011-04-06  5:04 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-04-05 22:33 [PATCH] sched: recover sched_yield task running time increase Alex Shi
2011-04-06  5:07 ` Rik van Riel [this message]
2011-04-06  6:15   ` Alex,Shi
2011-04-06  7:01     ` Mike Galbraith
2011-04-06 13:28       ` Shi, Alex
2011-04-07  2:44         ` Mike Galbraith
2011-04-06  8:04 ` Peter Zijlstra
2011-04-06 14:42   ` Rik van Riel
2011-04-06 15:25     ` Peter Zijlstra
2011-04-07  3:08   ` Alex,Shi
2011-04-07  6:13     ` Rik van Riel
2011-04-07  6:43       ` Alex,Shi
2011-04-07  8:52         ` Ingo Molnar

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