[PATCH v3 3/6] sched: Change wait_task_inactive()s match_state

Peter Zijlstra
2022-08-22T11:48:33Z

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.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
kernel/sched/core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3295,7 +3295,7 @@ unsigned long wait_task_inactive(struct
* is actually now running somewhere else!
*/
while (task_running(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();
}
@@ -3310,7 +3310,7 @@ unsigned long wait_task_inactive(struct
running = task_running(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);