From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0494EC432C3 for ; Fri, 15 Nov 2019 13:26:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C5E5F206CC for ; Fri, 15 Nov 2019 13:26:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="MFS84Rnk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727249AbfKON0K (ORCPT ); Fri, 15 Nov 2019 08:26:10 -0500 Received: from merlin.infradead.org ([205.233.59.134]:60420 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727223AbfKON0K (ORCPT ); Fri, 15 Nov 2019 08:26:10 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=TEb8/WL8bVEd71NxHtR37phcRaSkhErXkR9FY07ytKA=; b=MFS84Rnk/sNo2sMW8vd28u7TU /mToQ7X8C0NTmOEo0KhSE5Z/eEkVZjDiZwQQNKu4v/X4DEL9sVD179YU+CqIHmixrTWgzGv+As0HE /XBRfuy0vZOn6xH1CBQrVuXKja2BtBvFECm7vj4ekKNrPNNL/e/tPeiOS+DOJ+IQyY6UgUN8S/ikL X9F3N+N0gxcbtJ6U2fsAjgMLjD4v/nZCNxoEjIeB50NzAESO8N1oZw1mWzbSF+epLOK6Mse/ZVImf bybfcAQV4mkg9LTir4EL/eVyyR6Np9d2yp/mPmmyrLYo00/fU413tq5fr29I0JwawlM7TzYS2bFoQ pyO4zWNaQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1iVbbI-00087O-Vm; Fri, 15 Nov 2019 13:25:25 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id DD13D3006FB; Fri, 15 Nov 2019 14:24:12 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id DA5DF2B12DAAB; Fri, 15 Nov 2019 14:25:20 +0100 (CET) Date: Fri, 15 Nov 2019 14:25:20 +0100 From: Peter Zijlstra To: Vincent Guittot Cc: linux-kernel@vger.kernel.org, mingo@redhat.com, dietmar.eggemann@arm.com, juri.lelli@redhat.com, rostedt@goodmis.org, mgorman@suse.de, dsmythies@telus.net, linux-pm@vger.kernel.org, torvalds@linux-foundation.org, tglx@linutronix.de, sargun@sargun.me, tj@kernel.org, xiexiuqi@huawei.com, xiezhipeng1@huawei.com, srinivas.pandruvada@linux.intel.com Subject: Re: [PATCH v4] sched/freq: move call to cpufreq_update_util Message-ID: <20191115132520.GJ4131@hirez.programming.kicks-ass.net> References: <1573751251-3505-1-git-send-email-vincent.guittot@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1573751251-3505-1-git-send-email-vincent.guittot@linaro.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Thu, Nov 14, 2019 at 06:07:31PM +0100, Vincent Guittot wrote: > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index 69a81a5..3be44e1 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -3504,9 +3504,6 @@ update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq) > cfs_rq->load_last_update_time_copy = sa->last_update_time; > #endif > > - if (decayed) > - cfs_rq_util_change(cfs_rq, 0); > - > return decayed; > } This removes the call from the for_each_leaf_cfs_rq_safe() loop. > @@ -7543,18 +7544,19 @@ static void update_blocked_averages(int cpu) > const struct sched_class *curr_class; > struct rq_flags rf; > bool done = true; > + int decayed; > > rq_lock_irqsave(rq, &rf); > update_rq_clock(rq); > > /* > - * update_cfs_rq_load_avg() can call cpufreq_update_util(). Make sure > - * that RT, DL and IRQ signals have been updated before updating CFS. > + * update_load_avg() can call cpufreq_update_util(). Make sure that RT, > + * DL and IRQ signals have been updated before updating CFS. > */ > curr_class = rq->curr->sched_class; > - update_rt_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &rt_sched_class); > - update_dl_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &dl_sched_class); > - update_irq_load_avg(rq, 0); > + decayed = update_rt_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &rt_sched_class); > + decayed |= update_dl_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &dl_sched_class); > + decayed |= update_irq_load_avg(rq, 0); Should not all 3 have their windows aligned and thus alway return the exact same value? > > /* Don't need periodic decay once load/util_avg are null */ > if (others_have_blocked(rq)) > @@ -7567,9 +7569,13 @@ static void update_blocked_averages(int cpu) > for_each_leaf_cfs_rq_safe(rq, cfs_rq, pos) { > struct sched_entity *se; > > - if (update_cfs_rq_load_avg(cfs_rq_clock_pelt(cfs_rq), cfs_rq)) > + if (update_cfs_rq_load_avg(cfs_rq_clock_pelt(cfs_rq), cfs_rq)) { > update_tg_load_avg(cfs_rq, 0); > > + if (cfs_rq == &rq->cfs) > + decayed = 1; And that restores it. But should not also rq->cfs's window be aligned with the above 3? Meaning that this one, with exception of the list_del, covers all 4. > + } > + > /* Propagate pending load changes to the parent, if any: */ > se = cfs_rq->tg->se[cpu]; > if (se && !skip_blocked_update(se)) > @@ -7588,6 +7594,9 @@ static void update_blocked_averages(int cpu) > } > > update_blocked_load_status(rq, !done); > + > + if (decayed) > + cpufreq_update_util(rq, 0); > rq_unlock_irqrestore(rq, &rf); > } > > @@ -7644,22 +7653,22 @@ static inline void update_blocked_averages(int cpu) > struct cfs_rq *cfs_rq = &rq->cfs; > const struct sched_class *curr_class; > struct rq_flags rf; > + int decayed; > > rq_lock_irqsave(rq, &rf); > update_rq_clock(rq); > > - /* > - * update_cfs_rq_load_avg() can call cpufreq_update_util(). Make sure > - * that RT, DL and IRQ signals have been updated before updating CFS. > - */ > curr_class = rq->curr->sched_class; > - update_rt_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &rt_sched_class); > - update_dl_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &dl_sched_class); > - update_irq_load_avg(rq, 0); > + decayed = update_rt_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &rt_sched_class); > + decayed |= update_dl_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &dl_sched_class); > + decayed |= update_irq_load_avg(rq, 0); > > - update_cfs_rq_load_avg(cfs_rq_clock_pelt(cfs_rq), cfs_rq); > + decayed |= update_cfs_rq_load_avg(cfs_rq_clock_pelt(cfs_rq), cfs_rq); And that thus this one makes all 3 above redundant. > > update_blocked_load_status(rq, cfs_rq_has_blocked(cfs_rq) || others_have_blocked(rq)); > + > + if (decayed) > + cpufreq_update_util(rq, 0); > rq_unlock_irqrestore(rq, &rf); > } That is, I'm almost tempted to prefer a variant of your initial hack, that refuses to remove rq->cfs from the list. That avoids having to care about the rt,dl,irq decays (their windows align with rq->cfs) and makes smp/up similar. I still don't actually understand how any of this makes intel_pstate happy though.