Commit-ID: eeb60398639143c11ff2c8b509e3a471411bb5d3 Gitweb: https://git.kernel.org/tip/eeb60398639143c11ff2c8b509e3a471411bb5d3 Author: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> AuthorDate: Tue, 13 Feb 2018 13:37:26 +0000 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Wed, 21 Feb 2018 08:49:07 +0100 sched/fair: Defer calculation of 'prev_eff_load' in wake_affine_weight() until needed 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@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Cc: Giovanni Gherdovich <ggherdovich@xxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx> Cc: Mike Galbraith <efault@xxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/20180213133730.24064-3-mgorman@xxxxxxxxxxxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- 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 0132572..ae3e6f8 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; -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html