From a526d466798d65cff120ee00ef92931075bf3769 Mon Sep 17 00:00:00 2001 From: Morten Rasmussen Date: Thu, 6 Feb 2020 19:19:55 +0000 Subject: [PATCH] sched/topology: Remove SD_BALANCE_WAKE on asymmetric capacity systems SD_BALANCE_WAKE was previously added to lower sched_domain levels on asymmetric CPU capacity systems by commit: 9ee1cda5ee25 ("sched/core: Enable SD_BALANCE_WAKE for asymmetric capacity systems") to enable the use of find_idlest_cpu() and friends to find an appropriate CPU for tasks. That responsibility has now been shifted to select_idle_sibling() and friends, and hence the flag can be removed. Note that this causes asymmetric CPU capacity systems to no longer enter the slow wakeup path (find_idlest_cpu()) on wakeups - only on execs and forks (which is aligned with all other mainline topologies). Signed-off-by: Morten Rasmussen [Changelog tweaks] Signed-off-by: Valentin Schneider Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner Reviewed-by: Quentin Perret Link: https://lkml.kernel.org/r/20200206191957.12325-3-valentin.schneider@arm.com --- kernel/sched/topology.c | 15 +++------------ 1 file changed, 3 insertions(+), 12 deletions(-) diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index dfb64c0..0091188 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -1374,18 +1374,9 @@ sd_init(struct sched_domain_topology_level *tl, * Convert topological properties into behaviour. */ - if (sd->flags & SD_ASYM_CPUCAPACITY) { - struct sched_domain *t = sd; - - /* - * Don't attempt to spread across CPUs of different capacities. - */ - if (sd->child) - sd->child->flags &= ~SD_PREFER_SIBLING; - - for_each_lower_domain(t) - t->flags |= SD_BALANCE_WAKE; - } + /* Don't attempt to spread across CPUs of different capacities. */ + if ((sd->flags & SD_ASYM_CPUCAPACITY) && sd->child) + sd->child->flags &= ~SD_PREFER_SIBLING; if (sd->flags & SD_SHARE_CPUCAPACITY) { sd->imbalance_pct = 110; -- 2.7.4