From: Mikulas Patocka <mpatocka@xxxxxxxxxx> Save one spinlock by using waitqueue_active. We hold the bufio lock at this place, so no one can add entries to the waitqueue at this point. Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx> Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx> --- drivers/md/dm-bufio.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c index e5459741335d..cca43ed13fd1 100644 --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -1665,7 +1665,12 @@ static void __free_buffer_wake(struct dm_buffer *b) c->need_reserved_buffers--; } - wake_up(&c->free_buffer_wait); + /* + * We hold the bufio lock here, so no one can add entries to the + * wait queue anyway. + */ + if (unlikely(waitqueue_active(&c->free_buffer_wait))) + wake_up(&c->free_buffer_wait); } static enum evict_result cleaned(struct dm_buffer *b, void *context) -- 2.40.0
