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Re: cpufreq governors broken with !CONFIG_SMP?

From "Rafael J. Wysocki" <rjw@rjwysocki.net>
Newsgroups linux.kernel
Subject Re: cpufreq governors broken with !CONFIG_SMP?
Date 2016-05-06 02:10 +0200
Message-ID <rvBvb-20s-7@gated-at.bofh.it> (permalink)
References <rvBbQ-1tA-15@gated-at.bofh.it>
Organization linux.* mail to news gateway

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On Thursday, May 05, 2016 04:49:22 PM Steve Muckle wrote:
> While working on a few patches for schedutil I noticed that the CFS
> cpufreq hooks depend on PELT, which depends on CONFIG_SMP.
> 
> I compiled and ran a UP kernel with intel_pstate. Running a cpu-bound
> task did not result in the frequency increasing beyond fmin. For some reason
> ondemand is working for me with the same test, not sure why yet.
> 
> It appears dbs/intel-pstate/schedutil have a dependency on CONFIG_SMP
> now. Or am I missing something?

You're right AFAICS.

For governors other than schedutil fixing that would be a matter of
adding a !CONFIG_SMP variant of update_load_avg() that will call
cpufreq_update_util() and do nothing else.  It doesn't matter what
is passed via util and max then.

In turn, schedutil should probably depend on CONFIG_SMP.

Peter?

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Thread

cpufreq governors broken with !CONFIG_SMP? Steve Muckle <steve.muckle@linaro.org> - 2016-05-06 01:50 +0200
  Re: cpufreq governors broken with !CONFIG_SMP? "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-05-06 02:10 +0200
    Re: cpufreq governors broken with !CONFIG_SMP? Steve Muckle <steve.muckle@linaro.org> - 2016-05-06 02:30 +0200
      Re: cpufreq governors broken with !CONFIG_SMP? "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-05-06 02:40 +0200
      Re: cpufreq governors broken with !CONFIG_SMP? Peter Zijlstra <peterz@infradead.org> - 2016-05-06 13:50 +0200
    Re: cpufreq governors broken with !CONFIG_SMP? "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-05-06 02:30 +0200
      Re: cpufreq governors broken with !CONFIG_SMP? "Rafael J. Wysocki" <rafael@kernel.org> - 2016-05-06 13:50 +0200
      Re: cpufreq governors broken with !CONFIG_SMP? Peter Zijlstra <peterz@infradead.org> - 2016-05-06 13:50 +0200

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