From: Ingo Molnar <mingo@elte.hu>
To: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
Peter Zijlstra <peter@programming.kicks-ass.net>,
Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
Dhaval Giani <dhaval@linux.vnet.ibm.com>,
linux-kernel@vger.kernel.org, "Zhang,
Yanmin" <yanmin_zhang@linux.intel.com>
Subject: Re: Make yield_task_fair more efficient
Date: Thu, 21 Feb 2008 10:04:30 +0100 [thread overview]
Message-ID: <20080221090430.GA20055@elte.hu> (raw)
In-Reply-To: <47BD3B56.3090404@linux.vnet.ibm.com>
* Balbir Singh <balbir@linux.vnet.ibm.com> wrote:
> If you insist that sched_yield() is bad, I might agree, but how does
> my patch make things worse. [...]
it puts new instructions into the hotpath.
> [...] In my benchmarks, it has helped the sched_yield case, why is
> that bad? [...]
I had the same cache for the rightmost task in earlier CFS (it's a
really obvious thing) but removed it. It wasnt a bad idea, but it hurt
the fastpath hence i removed it. Algorithms and implementations are a
constant balancing act.
Ingo
next prev parent reply other threads:[~2008-02-21 9:05 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-02-21 5:33 Make yield_task_fair more efficient Balbir Singh
2008-02-21 6:04 ` Ingo Molnar
2008-02-21 6:51 ` Balbir Singh
2008-02-21 7:07 ` Ingo Molnar
2008-02-21 7:39 ` Balbir Singh
2008-02-21 8:43 ` Peter Zijlstra
2008-02-21 8:50 ` Balbir Singh
2008-02-21 9:04 ` Ingo Molnar [this message]
2008-02-21 9:31 ` Balbir Singh
2008-02-21 9:42 ` Ingo Molnar
2008-02-21 9:44 ` Balbir Singh
2008-02-21 9:43 ` Peter Zijlstra
2008-02-21 9:42 ` Balbir Singh
2008-02-21 10:01 ` Peter Zijlstra
2008-02-21 10:07 ` Balbir Singh
2008-02-21 11:12 ` Peter Zijlstra
2008-02-21 11:27 ` Balbir Singh
2008-02-21 20:38 ` Jens Axboe
2008-02-21 20:55 ` Jens Axboe
2008-02-22 3:27 ` Balbir Singh
2008-02-21 10:17 ` Balbir Singh
2008-02-21 12:02 ` Mike Galbraith
2008-02-21 12:06 ` Mike Galbraith
2008-02-21 13:29 ` Balbir Singh
2008-02-21 14:38 ` Jörn Engel
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