From d4cda03828f5c8eae35efcb08f520f8f1a35950e Mon Sep 17 00:00:00 2001 From: Todd Kjos Date: Wed, 13 Jul 2016 16:13:47 -0700 Subject: [PATCH] sched: use util instead of capacity to select busy cpu If cpus are busy, the cpu selection algorithm was favoring cpus with lower capacity. This can result in uneven packing since there will be a bias toward the same cpu until there is a capacity change. Instead use the utilization so there is immediate feedback as tasks are assigned BUG: 30115868 Change-Id: I0ac7ae3ab5d8f2f5a5838c29bb6da2c3e8ef44e8 --- kernel/sched/fair.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 0b065ff2f4f3..7b6e95aa7360 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5593,7 +5593,7 @@ static inline int find_best_target(struct task_struct *p, bool boosted) { int iter_cpu; int target_cpu = -1; - int target_capacity = 0; + int target_util = 0; int backup_capacity = 0; int best_idle_cpu = -1; int best_idle_cstate = INT_MAX; @@ -5649,10 +5649,10 @@ static inline int find_best_target(struct task_struct *p, bool boosted) if (new_util < cur_capacity) { if (cpu_rq(i)->nr_running) { - if (target_capacity == 0 || - target_capacity > cur_capacity) { + if (target_util == 0 || + target_util > new_util) { target_cpu = i; - target_capacity = cur_capacity; + target_util = new_util; } } else if (!boosted) { if (best_idle_cpu < 0 ||