diff mbox series

[6/6] blk-mq: never redirect polled IO completions

Message ID 20181123183411.8708-7-axboe@kernel.dk (mailing list archive)
State New, archived
Headers show
Series Various block optimizations | expand

Commit Message

Jens Axboe Nov. 23, 2018, 6:34 p.m. UTC 
It's pointless to do so, we are by definition on the CPU we want/need
to be, as that's the one waiting for a completion event.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 block/blk-mq.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

Comments

Christoph Hellwig Nov. 26, 2018, 8:18 a.m. UTC | #1 
On Fri, Nov 23, 2018 at 11:34:11AM -0700, Jens Axboe wrote:
> It's pointless to do so, we are by definition on the CPU we want/need
> to be, as that's the one waiting for a completion event.
> 
> Signed-off-by: Jens Axboe <axboe@kernel.dk>

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>
diff mbox series

Patch

diff --git a/block/blk-mq.c b/block/blk-mq.c
index ba3c7b6476b7..37674c1766a7 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -585,7 +585,12 @@  static void __blk_mq_complete_request(struct request *rq)
 		return;
 	}
 
-	if (!test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags)) {
+	/*
+	 * For a polled request, always complete locallly, it's pointless
+	 * to redirect the completion.
+	 */
+	if ((rq->cmd_flags & REQ_HIPRI) ||
+	    !test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags)) {
 		q->mq_ops->complete(rq);
 		return;
 	}