From b18cbd359d7216a57af9409a177fa58e7db827fb Mon Sep 17 00:00:00 2001 From: Qais Yousef Date: Tue, 18 Apr 2023 15:09:39 +0100 Subject: [PATCH] sched/uclamp: Cater for uclamp in find_energy_efficient_cpu()'s early exit condition commit d81304bc6193554014d4372a01debdf65e1e9a4d upstream. If the utilization of the woken up task is 0, we skip the energy calculation because it has no impact. But if the task is boosted (uclamp_min != 0) will have an impact on task placement and frequency selection. Only skip if the util is truly 0 after applying uclamp values. Change uclamp_task_cpu() signature to avoid unnecessary additional calls to uclamp_eff_get(). feec() is the only user now. Fixes: 732cd75b8c920 ("sched/fair: Select an energy-efficient CPU on task wake-up") Signed-off-by: Qais Yousef Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20220804143609.515789-8-qais.yousef@arm.com (cherry picked from commit d81304bc6193554014d4372a01debdf65e1e9a4d) Signed-off-by: Qais Yousef (Google) Signed-off-by: Greg Kroah-Hartman --- kernel/sched/fair.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 7acc21d639b2..40ed005ed46c 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3928,14 +3928,16 @@ static inline unsigned long task_util_est(struct task_struct *p) } #ifdef CONFIG_UCLAMP_TASK -static inline unsigned long uclamp_task_util(struct task_struct *p) +static inline unsigned long uclamp_task_util(struct task_struct *p, + unsigned long uclamp_min, + unsigned long uclamp_max) { - return clamp(task_util_est(p), - uclamp_eff_value(p, UCLAMP_MIN), - uclamp_eff_value(p, UCLAMP_MAX)); + return clamp(task_util_est(p), uclamp_min, uclamp_max); } #else -static inline unsigned long uclamp_task_util(struct task_struct *p) +static inline unsigned long uclamp_task_util(struct task_struct *p, + unsigned long uclamp_min, + unsigned long uclamp_max) { return task_util_est(p); } @@ -6836,7 +6838,7 @@ static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu) goto fail; sync_entity_load_avg(&p->se); - if (!task_util_est(p)) + if (!uclamp_task_util(p, p_util_min, p_util_max)) goto unlock; for (; pd; pd = pd->next) {