Re: sched: Avoid SMT siblings in select_idle_sibling() if possible

From: Ingo Molnar
Date: Thu Feb 23 2012 - 11:17:48 EST



* Srivatsa Vaddagiri <vatsa@xxxxxxxxxxxxxxxxxx> wrote:

> * Ingo Molnar <mingo@xxxxxxx> [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?

Well, I start at 3 or 5 and sometimes increase it to get a
meaningful stddev - i.e. one that is smaller than half of the
measured effect. (for cases where I expect an improvement and
want to measure it.)

Thanks,

Ingo
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