Re: cpufreq governors broken with !CONFIG_SMP?

From: Rafael J. Wysocki
Date: Thu May 05 2016 - 20:06:01 EST

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.