[PATCH 1/1] sched/uclamp: release per-task uclamp control if user set to default value

From: Yun Hsiang
Date: Mon Sep 28 2020 - 04:27:15 EST


If the user wants to release the util clamp and let cgroup to control it,
we need a method to reset.

So if the user set the task uclamp to the default value (0 for UCLAMP_MIN
and 1024 for UCLAMP_MAX), reset the user_defined flag to release control.

Signed-off-by: Yun Hsiang <hsiang023167@xxxxxxxxx>
---
kernel/sched/core.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 9a2fbf98fd6f..fa63d70d783a 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1187,6 +1187,7 @@ static void __setscheduler_uclamp(struct task_struct *p,
const struct sched_attr *attr)
{
enum uclamp_id clamp_id;
+ bool user_defined;

/*
* On scheduling class change, reset to default clamps for tasks
@@ -1210,14 +1211,16 @@ static void __setscheduler_uclamp(struct task_struct *p,
if (likely(!(attr->sched_flags & SCHED_FLAG_UTIL_CLAMP)))
return;

+ user_defined = attr->sched_util_min == 0 ? false : true;
if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MIN) {
uclamp_se_set(&p->uclamp_req[UCLAMP_MIN],
- attr->sched_util_min, true);
+ attr->sched_util_min, user_defined);
}

+ user_defined = attr->sched_util_max == 1024 ? false : true;
if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX) {
uclamp_se_set(&p->uclamp_req[UCLAMP_MAX],
- attr->sched_util_max, true);
+ attr->sched_util_max, user_defined);
}
}

--
2.25.1