diff mbox series

[dm-6.4,v2,5/9] dm bufio: use waitqueue_active in __free_buffer_wake

Message ID 20230324175656.85082-6-snitzer@kernel.org (mailing list archive)
State Superseded, archived
Delegated to: Mike Snitzer
Headers show
Series dm bufio, thin: improve concurrent IO performance | expand

Commit Message

Mike Snitzer March 24, 2023, 5:56 p.m. UTC 
From: Mikulas Patocka <mpatocka@redhat.com>

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@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
---
 drivers/md/dm-bufio.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index 929685011e02..b638ddd161b4 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -1669,7 +1669,12 @@  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)