From 612a064d80d24bafe739f5e0a654b657663dd1d6 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 [ Upstream commit c2e164ac33f75e0acb93004960c73bd9166d3d35 ] 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 Signed-off-by: Sasha Levin --- kernel/sched/fair.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index b3e25be58e2b..1d9c2482c5a3 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7289,9 +7289,6 @@ 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.