Re: [PATCH v3 4/6] add a new scheduler hook for context switch

Peter Zijlstra
2012-05-30T11:41:07Z

On Wed, 2012-05-30 at 13:20 +0200, Peter Zijlstra wrote:
>
> $ perf stat -e cycles --repeat 100 perf bench sched messaging -p -g 100
>
> 48,826,146,710 cycles # 2.470 GHz ( +- 0.17% )
> 2.149005270 seconds time elapsed ( +- 0.12% )

A repeat count of 250 dropped it down to:

2.144582157 seconds time elapsed ( +- 0.08% )

Also, if you're poking at the context switch path, something like:

$ taskset 1 perf stat -e cycles --repeat 10 perf bench sched pipe -l 100000

gives a good number and is usually more stable than hackbench.