From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751229AbeCIJEa (ORCPT ); Fri, 9 Mar 2018 04:04:30 -0500 Received: from terminus.zytor.com ([198.137.202.136]:43113 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751045AbeCIJE3 (ORCPT ); Fri, 9 Mar 2018 04:04:29 -0500 Date: Fri, 9 Mar 2018 01:04:09 -0800 From: tip-bot for Vincent Guittot Message-ID: Cc: linux-kernel@vger.kernel.org, tglx@linutronix.de, peterz@infradead.org, torvalds@linux-foundation.org, mingo@kernel.org, hpa@zytor.com, vincent.guittot@linaro.org Reply-To: torvalds@linux-foundation.org, peterz@infradead.org, vincent.guittot@linaro.org, mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, tglx@linutronix.de In-Reply-To: <1518517879-2280-3-git-send-email-vincent.guittot@linaro.org> References: <1518517879-2280-3-git-send-email-vincent.guittot@linaro.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched/fair: Reduce the periodic update duration Git-Commit-ID: 1936c53ce8c8d4555e9ccad2dc8d98e0637b11f7 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 1936c53ce8c8d4555e9ccad2dc8d98e0637b11f7 Gitweb: https://git.kernel.org/tip/1936c53ce8c8d4555e9ccad2dc8d98e0637b11f7 Author: Vincent Guittot AuthorDate: Tue, 13 Feb 2018 11:31:18 +0100 Committer: Ingo Molnar CommitDate: Fri, 9 Mar 2018 07:59:22 +0100 sched/fair: Reduce the periodic update duration Instead of using the cfs_rq_is_decayed() which monitors all *_avg and *_sum, we create a cfs_rq_has_blocked() which only takes care of util_avg and load_avg. We are only interested by these 2 values which are decaying faster than the *_sum so we can stop the periodic update earlier. Signed-off-by: Vincent Guittot Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: brendan.jackman@arm.com Cc: dietmar.eggemann@arm.com Cc: morten.rasmussen@foss.arm.com Cc: valentin.schneider@arm.com Link: http://lkml.kernel.org/r/1518517879-2280-3-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar --- kernel/sched/fair.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 78b06a0814d1..aad7c03dbad8 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7424,6 +7424,19 @@ static void attach_tasks(struct lb_env *env) rq_unlock(env->dst_rq, &rf); } +static inline bool cfs_rq_has_blocked(struct cfs_rq *cfs_rq) +{ + if (cfs_rq->avg.load_avg) + return true; + + if (cfs_rq->avg.util_avg) + return true; + + return false; +} + +#ifdef CONFIG_FAIR_GROUP_SCHED + static inline bool cfs_rq_is_decayed(struct cfs_rq *cfs_rq) { if (cfs_rq->load.weight) @@ -7441,8 +7454,6 @@ static inline bool cfs_rq_is_decayed(struct cfs_rq *cfs_rq) return true; } -#ifdef CONFIG_FAIR_GROUP_SCHED - static void update_blocked_averages(int cpu) { struct rq *rq = cpu_rq(cpu); @@ -7478,7 +7489,9 @@ static void update_blocked_averages(int cpu) */ if (cfs_rq_is_decayed(cfs_rq)) list_del_leaf_cfs_rq(cfs_rq); - else + + /* Don't need periodic decay once load/util_avg are null */ + if (cfs_rq_has_blocked(cfs_rq)) done = false; } @@ -7548,7 +7561,7 @@ static inline void update_blocked_averages(int cpu) update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq); #ifdef CONFIG_NO_HZ_COMMON rq->last_blocked_load_update_tick = jiffies; - if (cfs_rq_is_decayed(cfs_rq)) + if (!cfs_rq_has_blocked(cfs_rq)) rq->has_blocked_load = 0; #endif rq_unlock_irqrestore(rq, &rf);