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From: tip-bot for Mel Gorman <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: peterz@infradead.org, torvalds@linux-foundation.org,
	ggherdovich@suse.cz, efault@gmx.de, tglx@linutronix.de,
	mgorman@techsingularity.net, mingo@kernel.org,
	matt@codeblueprint.co.uk, hpa@zytor.com,
	linux-kernel@vger.kernel.org
Subject: [tip:sched/core] sched/fair: Avoid an unnecessary lookup of current CPU ID during wake_affine
Date: Wed, 21 Feb 2018 02:27:38 -0800	[thread overview]
Message-ID: <tip-7ebb66a12f85bc375beaf45ca900427fe47aa8f7@git.kernel.org> (raw)
In-Reply-To: <20180213133730.24064-2-mgorman@techsingularity.net>

Commit-ID:  7ebb66a12f85bc375beaf45ca900427fe47aa8f7
Gitweb:     https://git.kernel.org/tip/7ebb66a12f85bc375beaf45ca900427fe47aa8f7
Author:     Mel Gorman <mgorman@techsingularity.net>
AuthorDate: Tue, 13 Feb 2018 13:37:25 +0000
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Wed, 21 Feb 2018 08:49:07 +0100

sched/fair: Avoid an unnecessary lookup of current CPU ID during wake_affine

The only caller of wake_affine() knows the CPU ID. Pass it in instead of
rechecking it.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Giovanni Gherdovich <ggherdovich@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180213133730.24064-2-mgorman@techsingularity.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/sched/fair.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 820f94c..0132572 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5751,9 +5751,8 @@ wake_affine_weight(struct sched_domain *sd, struct task_struct *p,
 }
 
 static int wake_affine(struct sched_domain *sd, struct task_struct *p,
-		       int prev_cpu, int sync)
+		       int this_cpu, int prev_cpu, int sync)
 {
-	int this_cpu = smp_processor_id();
 	int target = nr_cpumask_bits;
 
 	if (sched_feat(WA_IDLE))
@@ -6376,7 +6375,7 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f
 		if (cpu == prev_cpu)
 			goto pick_cpu;
 
-		new_cpu = wake_affine(affine_sd, p, prev_cpu, sync);
+		new_cpu = wake_affine(affine_sd, p, cpu, prev_cpu, sync);
 	}
 
 	if (sd && !(sd_flag & SD_BALANCE_FORK)) {

  reply	other threads:[~2018-02-21 10:30 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-13 13:37 [PATCH 0/6] Reduce migrations and conflicts with automatic NUMA balancing v2 Mel Gorman
2018-02-13 13:37 ` [PATCH 1/6] sched/fair: Avoid an unnecessary lookup of current CPU ID during wake_affine Mel Gorman
2018-02-21 10:27   ` tip-bot for Mel Gorman [this message]
2018-02-13 13:37 ` [PATCH 2/6] sched/fair: Defer calculation of prev_eff_load in wake_affine until needed Mel Gorman
2018-02-21 10:28   ` [tip:sched/core] sched/fair: Defer calculation of 'prev_eff_load' in wake_affine_weight() " tip-bot for Mel Gorman
2018-02-13 13:37 ` [PATCH 3/6] sched/fair: Do not migrate on wake_affine_weight if weights are equal Mel Gorman
2018-02-21 10:28   ` [tip:sched/core] sched/fair: Do not migrate on wake_affine_weight() " tip-bot for Mel Gorman
2018-02-13 13:37 ` [PATCH 4/6] sched/fair: Do not migrate due to a sync wakeup on exit Mel Gorman
2018-02-21 10:29   ` [tip:sched/core] " tip-bot for Peter Zijlstra
2018-02-13 13:37 ` [PATCH 5/6] sched/fair: Consider SD_NUMA when selecting the most idle group to schedule on Mel Gorman
2018-02-21 10:29   ` [tip:sched/core] " tip-bot for Mel Gorman
2018-02-13 13:37 ` [PATCH 6/6] sched/numa: Delay retrying placement for automatic NUMA balance after wake_affine Mel Gorman
2018-02-13 14:01   ` Peter Zijlstra
2018-02-13 14:18     ` Mel Gorman
2018-02-13 14:43       ` Peter Zijlstra
2018-02-13 15:00         ` Mel Gorman
2018-02-13 15:10           ` Peter Zijlstra
2018-02-21 10:30   ` [tip:sched/core] sched/numa: Delay retrying placement for automatic NUMA balance after wake_affine() tip-bot for Mel Gorman
2018-05-07 11:06     ` Srikar Dronamraju
2018-05-09  8:41       ` Mel Gorman
2018-05-09 10:58         ` Srikar Dronamraju
2018-05-09 16:34           ` Mel Gorman

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