Commit 61b82dfb authored by Vincent Guittot's avatar Vincent Guittot Committed by Peter Zijlstra
Browse files

sched/fair: Do not try to migrate delayed dequeue task 



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

Signed-off-by: default avatarVincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarDietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lore.kernel.org/r/20241202174606.4074512-11-vincent.guittot@linaro.org
parent 736c55a0

kernel/sched/fair.c

+8 −4
Original line number Diff line number Diff line
@@ -9391,11 +9391,15 @@ 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 unless we migrate load, 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) && (env->migration_type != migrate_load))

		return 0;



	if (throttled_lb_pair(task_group(p), env->src_cpu, env->dst_cpu))

		return 0;