Re: [PATCH v2 0/4] locking/mutex: Enable optimistic spinning of lock waiter

[Peter Zijlstra]

On Mon, Mar 21, 2016 at 11:19:02PM -0400, Waiman Long wrote:
> Instead, the subject was
> 
> [lkp] [locking/mutex] 5267438002: +38.9%
> fileio.time.involuntary_context_switches
> 
>       4409 ±  1%     +38.9%       6126 ±  2%
> fileio.time.involuntary_context_switches
>       6.00 ±  0%     +33.3%       8.00 ±  0%
> fileio.time.percent_of_cpu_this_job_got
>      36.06 ±  0%     +43.0%      51.55 ±  0%  fileio.time.system_time
>    1828660 ±  0%     -92.5%     137258 ±  0%
> fileio.time.voluntary_context_switches
> 
> Given that the number of voluntary context switches dropped by 92.5%, an
> increase in involuntary context switches that is order of magnitude less
> than the voluntary context switches should be OK, I think.
> 
> Do you know how to report back that this increase is expected and is nothing
> to worry about? Do I just reply it back?

Nah, just ignore.