lkml.org 
[lkml]   [2022]   [Jan]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v3 0/4] sched/pelt: Relax the sync of *_sum with *_avg
On Wed, 12 Jan 2022 at 12:24, Sachin Sant <sachinp@linux.vnet.ibm.com> wrote:
>
>
> > On 11-Jan-2022, at 7:16 PM, Vincent Guittot <vincent.guittot@linaro.org> wrote:
> >
> > Rick reported performance regressions in bugzilla because of cpu
> > frequency being lower than before:
> > https://bugzilla.kernel.org/show_bug.cgi?id=215045
> >
> > He bisected the problem to:
> > commit 1c35b07e6d39 ("sched/fair: Ensure _sum and _avg values stay consistent")
> >
> > More details are available in commit message of patch 1.
> >
> > This patchset reverts the commit above and adds several checks when
> > propagating the changes in the hierarchy to make sure that we still have
> > coherent util_avg and util_sum.
> >
> > Dietmar found a simple way to reproduce the WARN fixed by
> > commit 1c35b07e6d39 ("sched/fair: Ensure _sum and _avg values stay consistent")
> > by looping on hackbench in several different sched group levels.
> >
> > This patchset as run on the reproducer with success but it probably needs
> > more tests by people who faced the WARN before.
> >
>
> I ran scheduler regression tests(including cfg_bandwidth) from LTP
> for about 6 hours. I did not observe any (new or previously reported)
> kernel warn messages.
>
> Based on this test result for ppc64le
> Tested-by: Sachin Sant <sachinp@linux.ibm.com>

Thanks

>
> -Sachin

\
 
 \ /
  Last update: 2022-01-12 14:18    [W:0.119 / U:0.064 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site