lkml.org 
[lkml]   [2021]   [Mar]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [sched/fair] b360fb5e59: stress-ng.vm-segv.ops_per_sec -13.9% regression
Date
On 23/02/21 12:36, Valentin Schneider wrote:
> On 23/02/21 10:30, kernel test robot wrote:
>> Greeting,
>>
>> FYI, we noticed a -13.9% regression of stress-ng.vm-segv.ops_per_sec due to commit:
>>
>>
>> commit: b360fb5e5954a8a440ef95bf11257e2e7ea90340 ("[PATCH v2 1/7] sched/fair: Ignore percpu threads for imbalance pulls")
>> url: https://github.com/0day-ci/linux/commits/Valentin-Schneider/sched-fair-misfit-task-load-balance-tweaks/20210219-211028
>> base: https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git c5e6fc08feb2b88dc5dac2f3c817e1c2a4cafda4
>>
>> in testcase: stress-ng
>> on test machine: 96 threads Intel(R) Xeon(R) Gold 6252 CPU @ 2.10GHz with 512G memory
>> with following parameters:
>>
>> nr_threads: 10%
>> disk: 1HDD
>> testtime: 60s
>> fs: ext4
>> class: vm
>> test: vm-segv
>> cpufreq_governor: performance
>> ucode: 0x5003003
>>

So I've been running this on my 32 CPU arm64 desktop with:
nr_threads: 10%
nr_threads: 50%
(20 iterations each)

In the 50% case I see a ~2% improvement, in the 10% a -0.3%
regression (another batch showed -0.08%)... Still far off from the reported
-14%. If it's really required I can go find an x86 box to test this on, but
so far it looks like a fluke.

\
 
 \ /
  Last update: 2021-03-03 20:18    [W:0.061 / U:1.892 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site