On 02/16/2016 03:51 AM, Peter Zijlstra wrote:
> On Fri, Feb 12, 2016 at 12:32:11PM -0500, Waiman Long wrote:
>> My own test on a 4-socket E7-4820 v3 system showed a regression of
>> about 4% in the high_systime workload with Peter's patch which this
>> new patch effectively eliminates.
>>
>> Testing on an 8-socket Westmere-EX server, however, has performance
>> change from -9% to than +140% on the fserver workload of AIM7
>> depending on how the system was set up.
> Subject: [lkp] [locking/mutex] aaca135480: -72.9% fsmark.files_per_sec
>
> My patch also generated the above email.
>
> Please also test that benchmark against this approach.
>
I also got an email from "kernel test robot", it didn't list fsmark at
all. 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?
Cheers,
Longman
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.