Commit 3b627a3f authored by Jens Axboe's avatar Jens Axboe
Browse files

block: clarify blk_add_timer() use case for blk-mq 



Just a comment update on not needing queue_lock, and that we aren't
really adding the request to a timeout list for !mq.

Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent bd5cecea

block/blk-timeout.c

+6 −0
Original line number Diff line number Diff line
@@ -186,6 +186,7 @@ unsigned long blk_rq_timeout(unsigned long timeout) 
 * Notes:

 *    Each request has its own timer, and as it is added to the queue, we

 *    set up the timer. When the request completes, we cancel the timer.

 *    Queue lock must be held for the non-mq case, mq case doesn't care.

 */

void blk_add_timer(struct request *req)

{
@@ -209,6 +210,11 @@ void blk_add_timer(struct request *req) 
		req->timeout = q->rq_timeout;



	req->deadline = jiffies + req->timeout;



	/*

	 * Only the non-mq case needs to add the request to a protected list.

	 * For the mq case we simply scan the tag map.

	 */

	if (!q->mq_ops)

		list_add_tail(&req->timeout_list, &req->q->timeout_list);