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Wysocki" , Alexander Gordeev , Anna-Maria Behnsen , Ben Segall , Boqun Feng , Christian Borntraeger , Dietmar Eggemann , Heiko Carstens , Ingo Molnar , Jan Kiszka , Joel Fernandes , Juri Lelli , Kieran Bingham , Madhavan Srinivasan , Mel Gorman , Michael Ellerman , Neeraj Upadhyay , Nicholas Piggin , "Paul E . McKenney" , Steven Rostedt , Sven Schnelle , Thomas Gleixner , Uladzislau Rezki , Valentin Schneider , Vasily Gorbik , Vincent Guittot , Viresh Kumar , Xin Zhao , linux-pm@vger.kernel.org, linux-s390@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH 09/15] tick/sched: Move dyntick-idle cputime accounting to cputime code Message-ID: <20260119143552.GH830229@noisy.programming.kicks-ass.net> References: <20260116145208.87445-1-frederic@kernel.org> <20260116145208.87445-10-frederic@kernel.org> X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260116145208.87445-10-frederic@kernel.org> On Fri, Jan 16, 2026 at 03:52:02PM +0100, Frederic Weisbecker wrote: > +static void kcpustat_idle_stop(struct kernel_cpustat *kc, ktime_t now) > { > + u64 *cpustat = kc->cpustat; > + ktime_t delta; > + > + if (!kc->idle_elapse) > + return; > + > + delta = ktime_sub(now, kc->idle_entrytime); > + > + write_seqcount_begin(&kc->idle_sleeptime_seq); > + if (nr_iowait_cpu(smp_processor_id()) > 0) > + cpustat[CPUTIME_IOWAIT] = ktime_add(cpustat[CPUTIME_IOWAIT], delta); > + else > + cpustat[CPUTIME_IDLE] = ktime_add(cpustat[CPUTIME_IDLE], delta); > + > + kc->idle_entrytime = now; > + kc->idle_elapse = false; > + write_seqcount_end(&kc->idle_sleeptime_seq); > } I realize this is mostly code movement; but do we really want to preserve ktime_{sub,add}() and all that? I mean, we killed that 32bit ktime nonsense ages ago. > -static void tick_nohz_stop_idle(struct tick_sched *ts, ktime_t now) > -{ > - u64 *cpustat = kcpustat_this_cpu->cpustat; > - ktime_t delta; > - > - if (vtime_generic_enabled_this_cpu()) > - return; > - > - if (WARN_ON_ONCE(!tick_sched_flag_test(ts, TS_FLAG_IDLE_ACTIVE))) > - return; > - > - delta = ktime_sub(now, ts->idle_entrytime); > - > - write_seqcount_begin(&ts->idle_sleeptime_seq); > - if (nr_iowait_cpu(smp_processor_id()) > 0) > - cpustat[CPUTIME_IOWAIT] = ktime_add(cpustat[CPUTIME_IOWAIT], delta); > - else > - cpustat[CPUTIME_IDLE] = ktime_add(cpustat[CPUTIME_IDLE], delta); > - > - ts->idle_entrytime = now; > - tick_sched_flag_clear(ts, TS_FLAG_IDLE_ACTIVE); > - write_seqcount_end(&ts->idle_sleeptime_seq); > - > - sched_clock_idle_wakeup_event(); > -}