Re: [lkp] [mm, page_alloc] e6cbd7f2ef: pixz.throughput -5.1% regression

From: Thorsten Leemhuis
Date: Sun Aug 28 2016 - 05:51:54 EST


Lo! On 08.08.2016 10:29, kernel test robot wrote:
>
> FYI, we noticed a -5.1% regression of pixz.throughput due to commit:
>
> commit e6cbd7f2efb433d717af72aa8510a9db6f7a7e05 ("mm, page_alloc: remove fair zone allocation policy")
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
>
> in testcase: pixz
> on test machine: 48 threads Ivytown Ivy Bridge-EP with 64G memory
> with following parameters:
>
> nr_threads: 100%
> cpufreq_governor: performance

Mel, this report made it to the regression list for 4.8, but it seems
nothing happened after the initial report. Was it discussed (and maybe
even fixed?) elsewhere? Or was it deemed not important enough? Should I
drop it for the regression list?

Side note: During 4.7 we already already had a performance regression in
the same test (and maybe the same test machine) that in the end wasn't
fixed. For details see the thread "795ae7a0de: pixz.throughput -9.1%
regression" (http://lkml.iu.edu/hypermail/linux/kernel/1606.0/01156.html ).

Ciao, Thorsten