From: Honglei Wang <jameshongleiwang@126.com>
Date: Wed, 8 Jan 2025 02:33:28 +0000 (+0800)
Subject: sched_ext: switch class when preempted by higher priority scheduler
X-Git-Tag: v6.13-rc7~16^2~1
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=68e449d849fd50bd5e61d8bd32b3458dbd3a3df6;p=thirdparty%2Flinux.git

sched_ext: switch class when preempted by higher priority scheduler

ops.cpu_release() function, if defined, must be invoked when preempted by
a higher priority scheduler class task. This scenario was skipped in
commit f422316d7466 ("sched_ext: Remove switch_class_scx()"). Let's fix
it.

Fixes: f422316d7466 ("sched_ext: Remove switch_class_scx()")
Signed-off-by: Honglei Wang <jameshongleiwang@126.com>
Acked-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---

diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index 11a0e1a9d86ef..68150e1104511 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -3037,7 +3037,7 @@ static void put_prev_task_scx(struct rq *rq, struct task_struct *p,
 		 */
 		if (p->scx.slice && !scx_rq_bypassing(rq)) {
 			dispatch_enqueue(&rq->scx.local_dsq, p, SCX_ENQ_HEAD);
-			return;
+			goto switch_class;
 		}
 
 		/*
@@ -3054,6 +3054,7 @@ static void put_prev_task_scx(struct rq *rq, struct task_struct *p,
 		}
 	}
 
+switch_class:
 	if (next && next->sched_class != &ext_sched_class)
 		switch_class(rq, next);
 }