Messages in this thread | | | From | "Ma, Chinang" <> | Date | Wed, 10 Sep 2008 17:07:32 -0700 | Subject | RE: 2.6.27-rc5 OLTP performance regression |
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When set to 10 ms the regression is about 0.4%. We get most of the 2%.
Chinang -----Original Message----- From: Ingo Molnar [mailto:mingo@elte.hu] Sent: Wednesday, September 10, 2008 10:35 AM To: Ma, Chinang Cc: Peter Zijlstra; Srivatsa Vaddagiri; Mike Galbraith; Gregory Haskins; Steven Rostedt; Nick Piggin; Siddha, Suresh B; Wilcox, Matthew R; Tripathi, Sharad C; Chilukuri, Harita; linux-kernel@vger.kernel.org Subject: Re: 2.6.27-rc5 OLTP performance regression
* Ma, Chinang <chinang.ma@intel.com> wrote:
> I increased the /proc/sys/kernel/sched_shares_ratelimit from 1 > millisecond to one second to reduce the frequency of shares update. > That was okay for OLTP workload. As Peter mentioned, a larger value > will reduce the accuracy of SMP fairness for group scheduler and the > ratelimit and using a larger default value may not be good for general > case.
does 10 msecs already get you most of the 2%? 1000 millisecond sounds very (and probably unacceptable) coarse.
Ingo
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