On Fri, Apr 3, 2020 at 11:20 PM Johannes Weiner <hannes@xxxxxxxxxxx> wrote: > > On Fri, Apr 03, 2020 at 04:55:25AM -0400, Yafang Shao wrote: > > @@ -690,7 +690,10 @@ static void psi_group_change(struct psi_group *group, int cpu, > > */ > > write_seqcount_begin(&groupc->seq); > > > > - record_times(groupc, cpu, false); > > + if (groupc->total_tasks) > > + record_times(groupc, cpu, false); > > + else > > + groupc->state_start = cpu_clock(cpu); > > This change appears is a no-op. If there are no tasks, > groupc->state_mask is 0, and the only thing record_times() does is > > groupc->state_start = cpu_clock(cpu); > > Did you encounter actual problems, or are you just reading the code? No real issues. Just reading the code and found it looks like a little weird. But as you explained that state_mask can also guarantee it then we don't need to make this change. Thanks for the explanation. Thanks Yafang
