lkml.org 
[lkml]   [2011]   [Sep]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: CFS Bandwidth Control - Test results of cgroups tasks pinned vs unpinnede
* Peter Zijlstra <a.p.zijlstra@chello.nl> [2011-09-13 16:19:39]:

> > Booting with "nohz=off" also helps significantly.
> >
> > With nohz=on, average idle time (over 1 min) is 10.3%
> > With nohz=off, average idle time (over 1 min) is 3.9%
>
> So we should put the cpufreq/idle governor into the nohz/idle path, it
> already tries to predict the idle duration in order to pick a C state,
> that same prediction should be used to determine if stopping the tick is
> worth it.

Hmm ..I tried performance governor and found that it slightly increases
idle time.

With nohz=off && ondemand governor, idle time = 4%
With nohz=off && performance governor on all cpus, idle time = 6%

I can't see obvious reasons for that ..afaict bandwidth capping should
be independent of frequency (i.e task gets capped by "used" time,
irrespective of frequency at which it was "using" the cpu)?

- vatsa


\
 
 \ /
  Last update: 2011-09-13 20:05    [W:0.119 / U:22.708 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site