Messages in this thread | | | From | Vincent Guittot <> | Date | Thu, 30 Mar 2017 15:21:57 +0200 | Subject | Re: [RFD PATCH 4/5] sched/cpufreq_schedutil: always consider all CPUs when deciding next freq |
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On 30 March 2017 at 10:58, Juri Lelli <juri.lelli@arm.com> wrote: > Hi, > > On 30/03/17 00:41, Rafael J. Wysocki wrote: >> On Friday, March 24, 2017 02:08:59 PM Juri Lelli wrote: >> > No assumption can be made upon the rate at which frequency updates get >> > triggered, as there are scheduling policies (like SCHED_DEADLINE) which >> > don't trigger them so frequently. >> > >> > Remove such assumption from the code. >> >> But the util/max values for idle CPUs may be stale, no? >> > > Right, that might be a problem. A proper solution I think would be to > remotely update such values for idle CPUs, and I believe Vincent is > working on a patch for that.
Yes. I'm working on a patch that will regularly update the blocked load/utilization of idle CPU. This update will be done on a slow pace to make sure that utilization and load will be decayed regularly
> > As mid-term workarounds, changing a bit the current one, come to my > mind: > > - consider TICK_NSEC (continue) only when SCHED_CPUFREQ_DL is not set > - remove CFS contribution (without triggering a freq update) when a CPU > enters IDLE; this might not work well, though, as we probably want > to keep in blocked util contribution for a bit > > What you think is the way to go? > > Thanks, > > - Juri
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