From 9ee1cda5ee25c7dd82acf25892e0d229e818f8c7 Mon Sep 17 00:00:00 2001 From: Morten Rasmussen Date: Mon, 25 Jul 2016 14:34:24 +0100 Subject: [PATCH] sched/core: Enable SD_BALANCE_WAKE for asymmetric capacity systems A domain with the SD_ASYM_CPUCAPACITY flag set indicate that sched_groups at this level and below do not include CPUs of all capacities available (e.g. group containing little-only or big-only CPUs in big.LITTLE systems). It is therefore necessary to put in more effort in finding an appropriate CPU at task wake-up by enabling balancing at wake-up (SD_BALANCE_WAKE) on all lower (child) levels. Signed-off-by: Morten Rasmussen Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: dietmar.eggemann@arm.com Cc: freedom.tan@mediatek.com Cc: keita.kobayashi.ym@renesas.com Cc: mgalbraith@suse.de Cc: sgurrappadi@nvidia.com Cc: vincent.guittot@linaro.org Cc: yuyang.du@intel.com Link: http://lkml.kernel.org/r/1469453670-2660-8-git-send-email-morten.rasmussen@arm.com Signed-off-by: Ingo Molnar --- kernel/sched/core.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 57394650c6ab..4695df6ed752 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6444,6 +6444,13 @@ sd_init(struct sched_domain_topology_level *tl, * Convert topological properties into behaviour. */ + if (sd->flags & SD_ASYM_CPUCAPACITY) { + struct sched_domain *t = sd; + + for_each_lower_domain(t) + t->flags |= SD_BALANCE_WAKE; + } + if (sd->flags & SD_SHARE_CPUCAPACITY) { sd->flags |= SD_PREFER_SIBLING; sd->imbalance_pct = 110;