From c2e164ac33f75e0acb93004960c73bd9166d3d35 Mon Sep 17 00:00:00 2001 From: Vincent Guittot Date: Thu, 6 Jul 2023 15:51:44 +0200 Subject: [PATCH] sched/fair: remove util_est boosting There is no need to use runnable_avg when estimating util_est and that even generates wrong behavior because one includes blocked tasks whereas the other one doesn't. This can lead to accounting twice the waking task p, once with the blocked runnable_avg and another one when adding its util_est. cpu's runnable_avg is already used when computing util_avg which is then compared with util_est. In some situation, feec will not select prev_cpu but another one on the same performance domain because of higher max_util Fixes: 7d0583cf9ec7 ("sched/fair, cpufreq: Introduce 'runnable boosting'") Signed-off-by: Vincent Guittot Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Dietmar Eggemann Tested-by: Dietmar Eggemann Link: https://lore.kernel.org/r/20230706135144.324311-1-vincent.guittot@linaro.org --- kernel/sched/fair.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index d3df5b1642a6..f55b0a72772e 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7320,9 +7320,6 @@ cpu_util(int cpu, struct task_struct *p, int dst_cpu, int boost) util_est = READ_ONCE(cfs_rq->avg.util_est.enqueued); - if (boost) - util_est = max(util_est, runnable); - /* * During wake-up @p isn't enqueued yet and doesn't contribute * to any cpu_rq(cpu)->cfs.avg.util_est.enqueued.