Re: [tip:sched/urgent] sched: Optimize task_sched_runtime()

[Ingo Molnar <mingo@kernel.org>]

* Davidlohr Bueso <davidlohr@hp.com> wrote:

> On Wed, 2013-11-13 at 09:25 -0800, tip-bot for Peter Zijlstra wrote:
> > Commit-ID:  911b2898b3c9fe0048e9485ad1629ed4fce330fd
> > Gitweb:     http://git.kernel.org/tip/911b2898b3c9fe0048e9485ad1629ed4fce330fd
> > Author:     Peter Zijlstra <peterz@infradead.org>
> > AuthorDate: Mon, 11 Nov 2013 18:21:56 +0100
> > Committer:  Ingo Molnar <mingo@kernel.org>
> > CommitDate: Wed, 13 Nov 2013 13:33:54 +0100
> > 
> > sched: Optimize task_sched_runtime()
> > 
> > Large multi-threaded apps like to hit this using do_sys_times() and
> > then queue up on the rq->lock.
> > 
> > Avoid when possible.
> > 
> > Larry reported ~20% performance increase his test case.
> > 
> > Reported-by: Larry Woodman <lwoodman@redhat.com>
> > Suggested-by: Paul Turner <pjt@google.com>
> > Signed-off-by: Peter Zijlstra <peterz@infradead.org>
> > Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
> > Cc: Linus Torvalds <torvalds@linux-foundation.org>
> > Cc: Andrew Morton <akpm@linux-foundation.org>
> > Link: http://lkml.kernel.org/r/20131111172925.GG26898@twins.programming.kicks-ass.net
> > Signed-off-by: Ingo Molnar <mingo@kernel.org>
> 
> For what it's worth:
> 
> Tested-by: Davidlohr Bueso <davidlohr@hp.com>

Thanks for the testing - the change is upstream already and unless it 
causes regressions it will be part of the v3.13 kernel.

Thanks,

	Ingo