Commit 9ba7f37e authored by Tejun Heo's avatar Tejun Heo
Browse files

sched_ext: Clean up SCX_EXIT_NONE handling in scx_disable_workfn() 



With the global states and disable machinery moved into scx_sched,
scx_disable_workfn() can only be scheduled and run for the specific
scheduler instance. This makes it impossible for scx_disable_workfn() to see
SCX_EXIT_NONE. Turn that condition into WARN_ON_ONCE().

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Reviewed-by: default avatarAndrea Righi <arighi@nvidia.com>
Acked-by: default avatarChangwoo Min <changwoo@igalia.com>
parent bff3b5ae

kernel/sched/ext.c

+2 −6
Original line number Diff line number Diff line
@@ -4752,13 +4752,9 @@ static void scx_disable_workfn(struct kthread_work *work) 


	kind = atomic_read(&sch->exit_kind);

	while (true) {

		/*

		 * NONE indicates that a new scx_ops has been registered since

		 * disable was scheduled - don't kill the new ops. DONE

		 * indicates that the ops has already been disabled.

		 */

		if (kind == SCX_EXIT_NONE || kind == SCX_EXIT_DONE)

		if (kind == SCX_EXIT_DONE)	/* already disabled? */

			return;

		WARN_ON_ONCE(kind == SCX_EXIT_NONE);

		if (atomic_try_cmpxchg(&sch->exit_kind, &kind, SCX_EXIT_DONE))

			break;

	}