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charset=us-ascii Content-Disposition: inline In-Reply-To: <1585904125-2819-1-git-send-email-laoar.shao@gmail.com> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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?