From: Qais Yousef qais.yousef@arm.com
[ Upstream commit d81304bc6193554014d4372a01debdf65e1e9a4d ]
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 qais.yousef@arm.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Link: https://lore.kernel.org/r/20220804143609.515789-8-qais.yousef@arm.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 2e782d79e80f..532e6cdf706d 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4108,14 +4108,16 @@ 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); } @@ -7029,7 +7031,7 @@ static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu) target = prev_cpu;
sync_entity_load_avg(&p->se); - if (!task_util_est(p)) + if (!uclamp_task_util(p, p_util_min, p_util_max)) goto unlock;
eenv_task_busy_time(&eenv, p, prev_cpu);