Messages in this thread | | | Date | Tue, 13 Sep 2011 23:31:46 +0530 | From | Srivatsa Vaddagiri <> | Subject | Re: CFS Bandwidth Control - Test results of cgroups tasks pinned vs unpinnede |
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* 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
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