From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752861AbeBFMAg (ORCPT ); Tue, 6 Feb 2018 07:00:36 -0500 Received: from terminus.zytor.com ([65.50.211.136]:48467 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752403AbeBFMA2 (ORCPT ); Tue, 6 Feb 2018 07:00:28 -0500 Date: Tue, 6 Feb 2018 03:56:02 -0800 From: tip-bot for Mel Gorman Message-ID: Cc: tglx@linutronix.de, peterz@infradead.org, mgorman@techsingularity.net, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, mingo@kernel.org, matt@codeblueprint.co.uk, hpa@zytor.com, efault@gmx.de Reply-To: mgorman@techsingularity.net, peterz@infradead.org, tglx@linutronix.de, efault@gmx.de, hpa@zytor.com, matt@codeblueprint.co.uk, mingo@kernel.org, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org In-Reply-To: <20180130104555.4125-3-mgorman@techsingularity.net> References: <20180130104555.4125-3-mgorman@techsingularity.net> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/urgent] sched/fair: Restructure wake_affine*() to return a CPU id Git-Commit-ID: 3b76c4a33959ca98a573cd9c94c8690d123912ca 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: 3b76c4a33959ca98a573cd9c94c8690d123912ca Gitweb: https://git.kernel.org/tip/3b76c4a33959ca98a573cd9c94c8690d123912ca Author: Mel Gorman AuthorDate: Tue, 30 Jan 2018 10:45:53 +0000 Committer: Ingo Molnar CommitDate: Tue, 6 Feb 2018 10:20:35 +0100 sched/fair: Restructure wake_affine*() to return a CPU id This is a preparation patch that has wake_affine*() return a CPU ID instead of a boolean. The intent is to allow the wake_affine() helpers to be avoided if a decision is already made. This patch has no functional change. Signed-off-by: Mel Gorman Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Matt Fleming Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20180130104555.4125-3-mgorman@techsingularity.net Signed-off-by: Ingo Molnar --- kernel/sched/fair.c | 35 +++++++++++++++++------------------ 1 file changed, 17 insertions(+), 18 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 0a551dfe..4c400d7 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5692,7 +5692,7 @@ static int wake_wide(struct task_struct *p) * scheduling latency of the CPUs. This seems to work * for the overloaded case. */ -static bool +static int wake_affine_idle(int this_cpu, int prev_cpu, int sync) { /* @@ -5702,15 +5702,15 @@ wake_affine_idle(int this_cpu, int prev_cpu, int sync) * node depending on the IO topology or IRQ affinity settings. */ if (idle_cpu(this_cpu) && cpus_share_cache(this_cpu, prev_cpu)) - return true; + return this_cpu; if (sync && cpu_rq(this_cpu)->nr_running == 1) - return true; + return this_cpu; - return false; + return nr_cpumask_bits; } -static bool +static int wake_affine_weight(struct sched_domain *sd, struct task_struct *p, int this_cpu, int prev_cpu, int sync) { @@ -5724,7 +5724,7 @@ wake_affine_weight(struct sched_domain *sd, struct task_struct *p, unsigned long current_load = task_h_load(current); if (current_load > this_eff_load) - return true; + return this_cpu; this_eff_load -= current_load; } @@ -5741,28 +5741,28 @@ wake_affine_weight(struct sched_domain *sd, struct task_struct *p, prev_eff_load *= 100 + (sd->imbalance_pct - 100) / 2; prev_eff_load *= capacity_of(this_cpu); - return this_eff_load <= prev_eff_load; + return this_eff_load <= prev_eff_load ? this_cpu : nr_cpumask_bits; } static int wake_affine(struct sched_domain *sd, struct task_struct *p, int prev_cpu, int sync) { int this_cpu = smp_processor_id(); - bool affine = false; + int target = nr_cpumask_bits; if (sched_feat(WA_IDLE)) - affine = wake_affine_idle(this_cpu, prev_cpu, sync); + target = wake_affine_idle(this_cpu, prev_cpu, sync); - if (sched_feat(WA_WEIGHT) && !affine) - affine = wake_affine_weight(sd, p, this_cpu, prev_cpu, sync); + if (sched_feat(WA_WEIGHT) && target == nr_cpumask_bits) + target = wake_affine_weight(sd, p, this_cpu, prev_cpu, sync); schedstat_inc(p->se.statistics.nr_wakeups_affine_attempts); - if (affine) { - schedstat_inc(sd->ttwu_move_affine); - schedstat_inc(p->se.statistics.nr_wakeups_affine); - } + if (target == nr_cpumask_bits) + return prev_cpu; - return affine; + schedstat_inc(sd->ttwu_move_affine); + schedstat_inc(p->se.statistics.nr_wakeups_affine); + return target; } static inline unsigned long task_util(struct task_struct *p); @@ -6355,8 +6355,7 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f if (cpu == prev_cpu) goto pick_cpu; - if (wake_affine(affine_sd, p, prev_cpu, sync)) - new_cpu = cpu; + new_cpu = wake_affine(affine_sd, p, prev_cpu, sync); } if (sd && !(sd_flag & SD_BALANCE_FORK)) {