Messages in this thread | | | Date | Thu, 23 Feb 2012 17:02:24 +0530 | From | Srivatsa Vaddagiri <> | Subject | Re: sched: Avoid SMT siblings in select_idle_sibling() if possible |
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* Ingo Molnar <mingo@elte.hu> [2012-02-23 12:26:50]:
> pro perf tip of the day: did you know that it's possible to run: > > perf stat --repeat 10 --null perf bench sched pipe
Ah yes ..had forgotten that! What is the recommended # of iterations to run?
> and get meaningful, normalized stddev calculations for free: > > 5.486491487 seconds time elapsed ( +- 5.50% ) > > the percentage at the end shows the level of standard deviation. > > You can add "--sync" as well, which will cause perf stat to call > sync() - this gives extra stability of individual iterations and > makes sure all IO cost is accounted to the right run.
Ok ..thanks for the 'pro' tip!! Will use it in my subsequent runs!
- vatsa
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