[PATCH 2/6] sched_ext: Start schedulers with consistent p->scx.slice values
From: Tejun Heo
Date: Wed Oct 09 2024 - 17:44:39 EST
The disable path caps p->scx.slice to SCX_SLICE_DFL. As the field is already
being ignored at this stage during disable, the only effect this has is that
when the next BPF scheduler is loaded, it won't see unreasonable left-over
slices. Ultimately, this shouldn't matter but it's better to start in a
known state. Drop p->scx.slice capping from the disable path and instead
reset it to SCX_SLICE_DFL in the enable path.
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
---
kernel/sched/ext.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index e08cfba33cb4..7d2fa78ba0c9 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -4473,7 +4473,6 @@ static void scx_ops_disable_workfn(struct kthread_work *work)
sched_deq_and_put_task(p, DEQUEUE_SAVE | DEQUEUE_MOVE, &ctx);
- p->scx.slice = min_t(u64, p->scx.slice, SCX_SLICE_DFL);
__setscheduler_prio(p, p->prio);
check_class_changing(task_rq(p), p, old_class);
@@ -5190,6 +5189,7 @@ static int scx_ops_enable(struct sched_ext_ops *ops, struct bpf_link *link)
sched_deq_and_put_task(p, DEQUEUE_SAVE | DEQUEUE_MOVE, &ctx);
+ p->scx.slice = SCX_SLICE_DFL;
__setscheduler_prio(p, p->prio);
check_class_changing(task_rq(p), p, old_class);
--
2.46.2