This barrier only applies to the read-modify-write operations; in
particular, it does not apply to the atomic_set() primitive.
Replace the barrier with an smp_mb().
Fixes: 6c0ca7ae292ad ("sbitmap: fix wakeup hang after sbq resize")
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxx>
Reported-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Andrea Parri <andrea.parri@xxxxxxxxxxxxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Omar Sandoval <osandov@xxxxxx>
Cc: linux-block@xxxxxxxxxxxxxxx
---
lib/sbitmap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/sbitmap.c b/lib/sbitmap.c
index 155fe38756ecf..4a7fc4915dfc6 100644
--- a/lib/sbitmap.c
+++ b/lib/sbitmap.c
@@ -435,7 +435,7 @@ static void sbitmap_queue_update_wake_batch(struct sbitmap_queue *sbq,
* to ensure that the batch size is updated before the wait
* counts.
*/
- smp_mb__before_atomic();
+ smp_mb();
for (i = 0; i < SBQ_WAIT_QUEUES; i++)
atomic_set(&sbq->ws[i].wait_cnt, 1);
}
--
2.7.4
