The following commit has been merged into the sched/core branch of tip: Commit-ID: 64297f2b03cc7a6d0184a435f1b296beca1bedd1 Gitweb: https://git.kernel.org/tip/64297f2b03cc7a6d0184a435f1b296beca1bedd1 Author: Peng Wang <rock...@linux.alibaba.com> AuthorDate: Sat, 11 Apr 2020 17:20:20 +08:00 Committer: Peter Zijlstra <pet...@infradead.org> CommitterDate: Thu, 30 Apr 2020 20:14:38 +02:00
sched/fair: Simplify the code of should_we_balance() We only consider group_balance_cpu() after there is no idle cpu. So, just do comparison before return at these two cases. Signed-off-by: Peng Wang <rock...@linux.alibaba.com> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Reviewed-by: Valentin Schneider <valentin.schnei...@arm.com> Reviewed-by: Vincent Guittot <vincent.guit...@linaro.org> Link: https://lkml.kernel.org/r/245c792f0e580b3ca342ad61257f4c066ee0f84f.1586594833.git.rock...@linux.alibaba.com --- kernel/sched/fair.c | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 3d6ce75..63419c6 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -9413,7 +9413,7 @@ static int active_load_balance_cpu_stop(void *data); static int should_we_balance(struct lb_env *env) { struct sched_group *sg = env->sd->groups; - int cpu, balance_cpu = -1; + int cpu; /* * Ensure the balancing environment is consistent; can happen @@ -9434,18 +9434,12 @@ static int should_we_balance(struct lb_env *env) if (!idle_cpu(cpu)) continue; - balance_cpu = cpu; - break; + /* Are we the first idle CPU? */ + return cpu == env->dst_cpu; } - if (balance_cpu == -1) - balance_cpu = group_balance_cpu(sg); - - /* - * First idle CPU or the first CPU(busiest) in this sched group - * is eligible for doing load balancing at this and above domains. - */ - return balance_cpu == env->dst_cpu; + /* Are we the first CPU of this group ? */ + return group_balance_cpu(sg) == env->dst_cpu; } /*
