Messages in this thread Patch in this message | | | Date | Thu, 21 Mar 2019 16:49:37 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [PATCH V3] cpufreq: Call transition notifier only once for each policy |
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On Wed, 20 Mar 2019, Viresh Kumar wrote:
> Currently we call these notifiers once for each CPU of the policy->cpus
Nitpick: We call nothing. The notifiers are called ....
> cpumask. It would be more optimal if the notifier can be called only > once and all the relevant information be provided to it. Out of the 23 > diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c > index 3fae23834069..b2fe665878f7 100644 > --- a/arch/x86/kernel/tsc.c > +++ b/arch/x86/kernel/tsc.c > @@ -958,10 +958,15 @@ static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val, > struct cpufreq_freqs *freq = data; > unsigned long *lpj; > > + if (WARN_ON_ONCE(cpumask_weight(freq->policy->related_cpus) != 1)) { > + mark_tsc_unstable("cpufreq changes: related CPUs affected"); > + return 0; > + }
You might add a check which ensures that policy->cpu == smp_processor_id() because if this is not the case ....
Thanks,
tglx
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