From: Qais Yousef <qais.yousef@xxxxxxx>
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 <qais.yousef@xxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220804143609.515789-8-qais.yousef@xxxxxxx
(cherry picked from commit d81304bc6193554014d4372a01debdf65e1e9a4d)
Signed-off-by: Qais Yousef (Google) <qyousef@xxxxxxxxxxx>
---
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 cd4eccdf3291..66939333bdd1 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3974,14 +3974,16 @@ 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);
}
@@ -6967,7 +6969,7 @@ 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;
for (; pd; pd = pd->next) {
--
2.25.1
