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

Glauber Costa
2012-05-30T12:10:43Z

On 05/30/2012 03:40 PM, Peter Zijlstra wrote:
> 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.
thanks for the pointers