Re: [lkp] [sched/fair] e210bffd39: perf-stat.cpu-migrations -36.0% decrease

From: Vincent Guittot
Date: Thu Aug 04 2016 - 05:12:23 EST


On 4 August 2016 at 11:01, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> On Thu, Aug 04, 2016 at 01:24:23PM +0800, kernel test robot wrote:
>>
>> FYI, we noticed perf-stat.cpu-migrations -36.0% decrease due to commit:
>>
>> commit e210bffd39d01b649c94b820c28ff112673266dd ("sched/fair: Fix and optimize the fork() path")
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
>>
>> in testcase: unixbench
>> on test machine: 16 threads Broadwell-DE with 8G memory
>> with following parameters:
>>
>> runtime: 300s
>> nr_task: 1
>> test: shell8
>> cpufreq_governor: performance
>>
>>
>
> Urgh, I so hate these reports. They're near useless :/
>
> It took me 3 readings to realize it was the unixbench testcase (why
> isn't that in the subject!?). But then I still haven't found the primary
> performance metric. Does the test improve, degrade or not change
> overall?

Yes, i have the same question

>
>