On 21-03-19, 16:49, Thomas Gleixner wrote:
> On Wed, 20 Mar 2019, Viresh Kumar wrote:
> >
> > 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 ....
How about something like this ?
if (WARN_ON_ONCE(cpumask_weight(freq->policy->related_cpus) != 1 ||
freq->policy->cpu != smp_processor_id())) {
mark_tsc_unstable("cpufreq changes: related CPUs affected");
return 0;
}
Thanks for your feedback.
--
viresh
