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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 2B32FC43331 for ; Tue, 12 Nov 2019 17:21:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EA9FB20659 for ; Tue, 12 Nov 2019 17:21:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="JKQJCuq9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726958AbfKLRVL (ORCPT ); Tue, 12 Nov 2019 12:21:11 -0500 Received: from mail-lf1-f66.google.com ([209.85.167.66]:33546 "EHLO mail-lf1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726923AbfKLRVL (ORCPT ); Tue, 12 Nov 2019 12:21:11 -0500 Received: by mail-lf1-f66.google.com with SMTP id d6so13100177lfc.0 for ; Tue, 12 Nov 2019 09:21:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=b5fDbApjKbQXmX0rR85/pftKRLxjK2Tg7QN5BVmg42M=; b=JKQJCuq9s0hJMHC/fLGFr+lsqMghhfoavYWjdyT6WGk/uIOLC7bMLfw8AeXc/3+Vk5 W3sn6Iwcm5J03TnrOa0xllu1hQgpPx9D6e942muNF+yhl2OJ+Fy8ws4UyubhN2Rr+PIp H5D7OR78BS8WOCf4rm18xnyNcTlayW9qKBKNILd32t5lbOjmlSiStQhe+qqOco8+6b3N FTjlndP3N/cbxkCKQySywblvE42KASIK1eIf/CnOVG9ufTDm0YftuBERsDYqjaPjILuZ BE6+Xngj+Dm3CcCB0BMeuYczDNIG1iN0deNtKSXFk0mDG5oj0SzhgY7a5qDlcwfNhPEY 8HCQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=b5fDbApjKbQXmX0rR85/pftKRLxjK2Tg7QN5BVmg42M=; b=lz3sXjyePyeZJNbEkfIVJFN58ndtJmEg2BvyX62naUfETqwkpnqIJJuIyxJSsxWT3H xU3tQlIPA3fEcwnNnoVgZJt1M6H/c/SWLc1wNBXa+73rngignR4n0yASQ1Ds/uhN+lcI UYzj8qiQUIatNPwmesBD8EQXZULU/T2V6OHz2vKVTz9bbIfHF3GRtauWgczg1Xiy4Ptk 24vnfcuAxkfrxUMYz1nil1xVJrzJLCGOPHCt4R6AutygPm1VN8XSsyNw/maUboD9Bob3 Hsfv0tAESgCFml2tiu/6gHP90CJnbV3V3531GQavJx5EdyhPeSo5Ti5hbn9EonpEzgH8 0ymQ== X-Gm-Message-State: APjAAAWIOLY1CtjfN4hN8QdaetfOZp3ze2cleKVVW9mpa7BOgYgbg0// pejVz5mZgMBxcG2HDSkiRkzFHEHDn+fvtgdr1b/DGg== X-Google-Smtp-Source: APXvYqwpta/gsSZDZVP/J0C1gtL/VrrATsv2UTWozfFFXXndIiFUHXFw4NJYkeeIzbXDrA/NXRdJAHObql5bCcgyLKM= X-Received: by 2002:a19:800a:: with SMTP id b10mr20916798lfd.15.1573579268285; Tue, 12 Nov 2019 09:21:08 -0800 (PST) MIME-Version: 1.0 References: <1573570093-1340-1-git-send-email-vincent.guittot@linaro.org> <20191112150544.GA3664@linaro.org> In-Reply-To: From: Vincent Guittot Date: Tue, 12 Nov 2019 18:20:56 +0100 Message-ID: Subject: Re: [PATCH v2] sched/freq: move call to cpufreq_update_util To: Valentin Schneider Cc: linux-kernel , Ingo Molnar , Peter Zijlstra , Dietmar Eggemann , Juri Lelli , Steven Rostedt , Mel Gorman , Doug Smythies , "open list:THERMAL" , Linus Torvalds , Thomas Gleixner , Sargun Dhillon , Tejun Heo , Xie XiuQi , xiezhipeng1@huawei.com, Srinivas Pandruvada Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Tue, 12 Nov 2019 at 18:11, Valentin Schneider wrote: > > Hi Vincent, > > I didn't see anything in that reply, was that just a spurious email? there were a typo in one email address in the 1st message > > On 12/11/2019 15:05, Vincent Guittot wrote: > > Le Tuesday 12 Nov 2019 =C3=A0 15:48:13 (+0100), Vincent Guittot a =C3= =A9crit : > >> update_cfs_rq_load_avg() calls cfs_rq_util_change() everytime pelt dec= ays, > >> which might be inefficient when cpufreq driver has rate limitation. > >> > >> When a task is attached on a CPU, we have call path: > >> > >> update_blocked_averages() > >> update_cfs_rq_load_avg() > >> cfs_rq_util_change -- > trig frequency update > >> attach_entity_load_avg() > >> cfs_rq_util_change -- > trig frequency update > >> > >> The 1st frequency update will not take into account the utilization of= the > >> newly attached task and the 2nd one might be discard because of rate > >> limitation of the cpufreq driver. > >> > >> update_cfs_rq_load_avg() is only called by update_blocked_averages() > >> and update_load_avg() so we can move the call to > >> {cfs_rq,cpufreq}_util_change() into these 2 functions. It's also > >> interesting to notice that update_load_avg() already calls directly > >> cfs_rq_util_change() for !SMP case. > >> > >> This changes will also ensure that cpufreq_update_util() is called eve= n > >> when there is no more CFS rq in the leaf_cfs_rq_list to update but onl= y > >> irq, rt or dl pelt signals. > >> > >> Reported-by: Doug Smythies > >> Fixes: 039ae8bcf7a5 ("sched/fair: Fix O(nr_cgroups) in the load balanc= ing path") > >> Signed-off-by: Vincent Guittot > >> > >> --- > >> > >> I have just rebased the patch on latest tip/sched/core and made it a p= roper > >> patchset after Doug reported that the problem has diseappeared accordi= ng to > >> his 1st results but tests results are not all based on the same v5.4-r= cX > >> and with menu instead of teo governor. > >> > >> kernel/sched/fair.c | 33 +++++++++++++++++++++------------ > >> 1 file changed, 21 insertions(+), 12 deletions(-) > >> > >> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > >> index e458f52..c93d534 100644 > >> --- a/kernel/sched/fair.c > >> +++ b/kernel/sched/fair.c > >> @@ -3508,9 +3508,6 @@ update_cfs_rq_load_avg(u64 now, struct cfs_rq *c= fs_rq) > >> cfs_rq->load_last_update_time_copy =3D sa->last_update_time; > >> #endif > >> > >> - if (decayed) > >> - cfs_rq_util_change(cfs_rq, 0); > >> - > >> return decayed; > >> } > >> > >> @@ -3620,8 +3617,12 @@ static inline void update_load_avg(struct cfs_r= q *cfs_rq, struct sched_entity *s > >> attach_entity_load_avg(cfs_rq, se, SCHED_CPUFREQ_MIGRATIO= N); > >> update_tg_load_avg(cfs_rq, 0); > >> > >> - } else if (decayed && (flags & UPDATE_TG)) > >> - update_tg_load_avg(cfs_rq, 0); > >> + } else if (decayed) { > >> + cfs_rq_util_change(cfs_rq, 0); > >> + > >> + if (flags & UPDATE_TG) > >> + update_tg_load_avg(cfs_rq, 0); > >> + } > >> } > >> > >> #ifndef CONFIG_64BIT > >> @@ -7484,6 +7485,7 @@ static void update_blocked_averages(int cpu) > >> const struct sched_class *curr_class; > >> struct rq_flags rf; > >> bool done =3D true; > >> + int decayed =3D 0; > >> > >> rq_lock_irqsave(rq, &rf); > >> update_rq_clock(rq); > >> @@ -7493,9 +7495,9 @@ static void update_blocked_averages(int cpu) > >> * that RT, DL and IRQ signals have been updated before updating = CFS. > >> */ > >> curr_class =3D rq->curr->sched_class; > >> - update_rt_rq_load_avg(rq_clock_pelt(rq), rq, curr_class =3D=3D &r= t_sched_class); > >> - update_dl_rq_load_avg(rq_clock_pelt(rq), rq, curr_class =3D=3D &d= l_sched_class); > >> - update_irq_load_avg(rq, 0); > >> + decayed |=3D update_rt_rq_load_avg(rq_clock_pelt(rq), rq, curr_cl= ass =3D=3D &rt_sched_class); > >> + decayed |=3D update_dl_rq_load_avg(rq_clock_pelt(rq), rq, curr_cl= ass =3D=3D &dl_sched_class); > >> + decayed |=3D update_irq_load_avg(rq, 0); > >> > >> /* Don't need periodic decay once load/util_avg are null */ > >> if (others_have_blocked(rq)) > >> @@ -7529,6 +7531,9 @@ 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); > >> } > >> > >> @@ -7585,6 +7590,7 @@ static inline void update_blocked_averages(int c= pu) > >> struct cfs_rq *cfs_rq =3D &rq->cfs; > >> const struct sched_class *curr_class; > >> struct rq_flags rf; > >> + int decayed =3D 0; > >> > >> rq_lock_irqsave(rq, &rf); > >> update_rq_clock(rq); > >> @@ -7594,13 +7600,16 @@ static inline void update_blocked_averages(int= cpu) > >> * that RT, DL and IRQ signals have been updated before updating = CFS. > >> */ > >> curr_class =3D rq->curr->sched_class; > >> - update_rt_rq_load_avg(rq_clock_pelt(rq), rq, curr_class =3D=3D &r= t_sched_class); > >> - update_dl_rq_load_avg(rq_clock_pelt(rq), rq, curr_class =3D=3D &d= l_sched_class); > >> - update_irq_load_avg(rq, 0); > >> + decayed |=3D update_rt_rq_load_avg(rq_clock_pelt(rq), rq, curr_cl= ass =3D=3D &rt_sched_class); > >> + decayed |=3D update_dl_rq_load_avg(rq_clock_pelt(rq), rq, curr_cl= ass =3D=3D &dl_sched_class); > >> + decayed |=3D update_irq_load_avg(rq, 0); > >> > >> - update_cfs_rq_load_avg(cfs_rq_clock_pelt(cfs_rq), cfs_rq); > >> + decayed |=3D update_cfs_rq_load_avg(cfs_rq_clock_pelt(cfs_rq), cf= s_rq); > >> > >> update_blocked_load_status(rq, cfs_rq_has_blocked(cfs_rq) || othe= rs_have_blocked(rq)); > >> + > >> + if (decayed) > >> + cpufreq_update_util(rq, 0); > >> rq_unlock_irqrestore(rq, &rf); > >> } > >> > >> -- > >> 2.7.4 > >>