Re: [lkp-robot] [mm, mlock, vmscan] 9c4e6b1a70: stress-ng.hdd.ops_per_sec -7.9% regression

From: Ye Xiaolong
Date: Sun Feb 25 2018 - 21:59:08 EST


Hi, Shakeel

On 02/25, Shakeel Butt wrote:
>On Sun, Feb 25, 2018 at 6:44 AM, kernel test robot
><xiaolong.ye@xxxxxxxxx> wrote:
>>
>> Greeting,
>>
>> FYI, we noticed a -7.9% regression of stress-ng.hdd.ops_per_sec due to commit:
>>
>>
>> commit: 9c4e6b1a7027f102990c0395296015a812525f4d ("mm, mlock, vmscan: no more skipping pagevecs")
>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
>>
>> in testcase: stress-ng
>> on test machine: 88 threads Intel(R) Xeon(R) CPU E5-2699 v4 @ 2.20GHz with 128G memory
>> with following parameters:
>>
>
>Hi Xiaolong,
>
>Is there a way I can get the output of "perf record -a -g" running in
>parallel to the actual test on this machine. As I have mentioned
>before I am not able to reproduce this issue. However I am trying to
>repro on a VM with 4 vcpus and 4 GiB memory and I don't see any
>difference. I am suspecting that it may repro on a larger machine but
>I don't have access to one.
>

perf.data attached. It was generated via `perf record -q -ag --realtime=1 -m 256`

Thanks,
Xiaolong

>thanks,
>Shakeel