From: Mel Gorman <mgorman@techsingularity.net>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>, Mike Galbraith <efault@gmx.de>,
Matt Fleming <matt@codeblueprint.co.uk>,
Giovanni Gherdovich <ggherdovich@suse.cz>,
LKML <linux-kernel@vger.kernel.org>,
Mel Gorman <mgorman@techsingularity.net>
Subject: [PATCH 2/6] sched/fair: Defer calculation of prev_eff_load in wake_affine until needed
Date: Tue, 13 Feb 2018 13:37:26 +0000 [thread overview]
Message-ID: <20180213133730.24064-3-mgorman@techsingularity.net> (raw)
In-Reply-To: <20180213133730.24064-1-mgorman@techsingularity.net>
On sync wakeups, the previous CPU effective load may not be used so delay
the calculation until it's needed.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
---
kernel/sched/fair.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 4b3e86eb2222..c1091cb023c4 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5724,7 +5724,6 @@ wake_affine_weight(struct sched_domain *sd, struct task_struct *p,
unsigned long task_load;
this_eff_load = target_load(this_cpu, sd->wake_idx);
- prev_eff_load = source_load(prev_cpu, sd->wake_idx);
if (sync) {
unsigned long current_load = task_h_load(current);
@@ -5742,6 +5741,7 @@ wake_affine_weight(struct sched_domain *sd, struct task_struct *p,
this_eff_load *= 100;
this_eff_load *= capacity_of(prev_cpu);
+ prev_eff_load = source_load(prev_cpu, sd->wake_idx);
prev_eff_load -= task_load;
if (sched_feat(WA_BIAS))
prev_eff_load *= 100 + (sd->imbalance_pct - 100) / 2;
--
2.15.1
next prev parent reply other threads:[~2018-02-13 13:37 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:sched/core] " tip-bot for Mel Gorman
2018-02-13 13:37 ` Mel Gorman [this message]
2018-02-21 10:28 ` [tip:sched/core] sched/fair: Defer calculation of 'prev_eff_load' in wake_affine_weight() until needed 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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