On 29-10-20, 19:17, zhuguangqing83 wrote:
> I think your patch is ok for tackling this problem.
Great.
> > diff --git a/kernel/sched/cpufreq_schedutil.c
> > b/kernel/sched/cpufreq_schedutil.c
> > index 0c5c61a095f6..8991cc31b011 100644
> > --- a/kernel/sched/cpufreq_schedutil.c
> > +++ b/kernel/sched/cpufreq_schedutil.c
> > @@ -121,13 +121,8 @@ static void sugov_fast_switch(struct sugov_policy
> > *sg_policy, u64 time,
> > static void sugov_deferred_update(struct sugov_policy *sg_policy, u64 time,
> > unsigned int next_freq)
> > {
> > - if (!sugov_update_next_freq(sg_policy, time, next_freq))
> > - return;
> > -
> > - if (!sg_policy->work_in_progress) {
> > - sg_policy->work_in_progress = true;
> > + if (sugov_update_next_freq(sg_policy, time, next_freq))
> > irq_work_queue(&sg_policy->irq_work);
> > - }
> > }
> >
> > /**
> > @@ -159,6 +154,15 @@ static unsigned int get_next_freq(struct sugov_policy
> > *sg_policy,
> > unsigned int freq = arch_scale_freq_invariant() ?
> > policy->cpuinfo.max_freq : policy->cur;
> >
> > + /*
> > + * The previous frequency update didn't go as we expected it to be.
> > Lets
> > + * start again to make sure we don't miss any updates.
> > + */
> > + if (unlikely(policy->cur != sg_policy->next_freq)) {
> > + sg_policy->next_freq = 0;
> > + sg_policy->cached_raw_freq = 0;
> > + }
> > +
> > freq = map_util_freq(util, freq, max);
> >
> > if (freq == sg_policy->cached_raw_freq &&
> > !sg_policy->need_freq_update)
> > @@ -337,8 +341,14 @@ static void sugov_update_single(struct
> > update_util_data *hook, u64 time,
> >
> > ignore_dl_rate_limit(sg_cpu, sg_policy);
> >
> > + if (!sg_policy->policy->fast_switch_enabled) {
> > + raw_spin_lock(&sg_policy->update_lock);
> > + if (sg_policy->work_in_progress)
> > + goto unlock;
> > + }
> > +
>
> Maybe it's better to bring the following code before the code above.
> if (!sugov_should_update_freq(sg_policy, time))
> return;
Maybe not. We want to avoid everything in case a freq-update is on the
way elsewhere as there are other flags we are touching in
sugov_should_update_freq().
I will send a proper patch for this shortly. It would be helpful if
you can give it a go and provide your tested-by.
--
viresh
