Commit 9204a97f authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

sched: Change wait_task_inactive()s match_state 



Make wait_task_inactive()'s @match_state work like ttwu()'s @state.

That is, instead of an equal comparison, use it as a mask. This allows
matching multiple block conditions.

(removes the unlikely; it doesn't make sense how it's only part of the
condition)

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220822114648.856734578@infradead.org
parent 1fbcaa92

kernel/sched/core.c

+2 −2
Original line number Diff line number Diff line
@@ -3294,7 +3294,7 @@ unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state 
		 * is actually now running somewhere else!

		 */

		while (task_on_cpu(rq, p)) {

			if (match_state && unlikely(READ_ONCE(p->__state) != match_state))

			if (match_state && !(READ_ONCE(p->__state) & match_state))

				return 0;

			cpu_relax();

		}
@@ -3309,7 +3309,7 @@ unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state 
		running = task_on_cpu(rq, p);

		queued = task_on_rq_queued(p);

		ncsw = 0;

		if (!match_state || READ_ONCE(p->__state) == match_state)

		if (!match_state || (READ_ONCE(p->__state) & match_state))

			ncsw = p->nvcsw | LONG_MIN; /* sets MSB */

		task_rq_unlock(rq, p, &rf);