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From: Steve Muckle <steve.muckle@linaro.org>
X-Google-Original-From: Steve Muckle <smuckle@linaro.org>
Date: Thu, 19 May 2016 15:59:39 -0700
To: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Steve Muckle <steve.muckle@linaro.org>,
        Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@redhat.com>,
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        Viresh Kumar <viresh.kumar@linaro.org>,
        Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
        Len Brown <lenb@kernel.org>
Subject: Re: [PATCH 2/5] cpufreq: schedutil: support scheduler cpufreq
 callbacks on remote CPUs
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On Thu, May 19, 2016 at 10:55:23PM +0200, Rafael J. Wysocki wrote:
> >> > +static inline bool sugov_queue_remote_callback(struct sugov_policy *sg_policy,
> >> > +                                        int cpu)
> >> > +{
> >> > +       struct cpufreq_policy *policy = sg_policy->policy;
> >> > +
> >> > +       if (!cpumask_test_cpu(smp_processor_id(), policy->cpus)) {
> >>
> >> This check is overkill for policies that aren't shared (and we have a
> >> special case for them already).
> >
> > I don't see why it is overkill -
> 
> Because it requires more computation, memory accesses etc than simply
> comparing smp_processor_id() with cpu.

Do you have a preference on how to restructure this? Otherwise I'll
create a second version of sugov_update_commit, factoring out as much of
it as I can into two inline sub-functions. 

...
> 
> > but it seems like an odd inconsistency for the governor to trace unchanged
> > frequencies when fast switches are enabled but not otherwise. It'd be
> > useful I think for profiling and tuning if the tracing was consistent.
> 
> Well, fair enough.
> 
> > This behavioral change is admittedly not part of the purpose of the
> > patch and could be split out if needbe.
> 
> No need to split IMO, but it might be prudent to mention that change
> in behavior in the changelog.

Will do.

thanks,
Steve