[PATCH 7/9] sched/fair: Do not try to migrate delayed dequeue task

From: Vincent Guittot
Date: Thu Nov 28 2024 - 04:29:08 EST


Migrating a delayed dequeued task doesn't help in balancing the number
of runnable tasks in the system.

Signed-off-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
---
kernel/sched/fair.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 1b4f1b610543..9d80f3a61082 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -9405,11 +9405,15 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env)

/*
* We do not migrate tasks that are:
- * 1) throttled_lb_pair, or
- * 2) cannot be migrated to this CPU due to cpus_ptr, or
- * 3) running (obviously), or
- * 4) are cache-hot on their current CPU.
+ * 1) delayed dequeued, or
+ * 2) throttled_lb_pair, or
+ * 3) cannot be migrated to this CPU due to cpus_ptr, or
+ * 4) running (obviously), or
+ * 5) are cache-hot on their current CPU.
*/
+ if (p->se.sched_delayed)
+ return 0;
+
if (throttled_lb_pair(task_group(p), env->src_cpu, env->dst_cpu))
return 0;

--
2.43.0