dm: don't schedule delayed run of the queue if nothing to do
authorMike Snitzer <snitzer@redhat.com>
Wed, 25 Feb 2015 01:49:18 +0000 (20:49 -0500)
committerMike Snitzer <snitzer@redhat.com>
Wed, 15 Apr 2015 16:10:13 +0000 (12:10 -0400)
In request-based DM's dm_request_fn(), if blk_peek_request() returns
NULL just return.  Avoids unnecessary blk_delay_queue().

Reported-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
drivers/md/dm.c

index 7924c00e0716849620177a3ff24a42c9bfa0c6fa..6f854287384b51ac73d224200d7bc0be06215a3c 100644 (file)
@@ -1963,7 +1963,7 @@ static void dm_request_fn(struct request_queue *q)
        while (!blk_queue_stopped(q)) {
                rq = blk_peek_request(q);
                if (!rq)
-                       goto delay_and_out;
+                       goto out;
 
                /* always use block 0 to find the target for flushes for now */
                pos = 0;