[PATCH v2 04/13] dm-rq: Adjust requeuing delays

From: Bart Van Assche <bart.vanassche@sandisk.com>
To: Mike Snitzer <snitzer@redhat.com>
Cc: Bart Van Assche <bart.vanassche@sandisk.com>,
	dm-devel@redhat.com, Christoph Hellwig <hch@lst.de>
Subject: [PATCH v2 04/13] dm-rq: Adjust requeuing delays
Date: Thu, 27 Apr 2017 10:11:17 -0700	[thread overview]
Message-ID: <20170427171126.26814-5-bart.vanassche@sandisk.com> (raw)
In-Reply-To: <20170427171126.26814-1-bart.vanassche@sandisk.com>

Reduce the requeue delay in dm_requeue_original_request() from 5s
to 0.5s to avoid that this delay slows down failover or failback.
Increase the requeue delay in dm_mq_queue_rq() from 0.1s to 0.5s
to reduce the system load if immediate requeuing has been requested
by the dm driver.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
---
 drivers/md/dm-rq.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index 0b081d170087..c53debdcd7dc 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -280,7 +280,7 @@ static void dm_requeue_original_request(struct dm_rq_target_io *tio, bool delay_
 	if (!rq->q->mq_ops)
 		dm_old_requeue_request(rq);
 	else
-		dm_mq_delay_requeue_request(rq, delay_requeue ? 5000 : 0);
+		dm_mq_delay_requeue_request(rq, delay_requeue ? 500/*ms*/ : 0);
 
 	rq_completed(md, rw, false);
 }
@@ -755,7 +755,7 @@ static int dm_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
 		/* Undo dm_start_request() before requeuing */
 		rq_end_stats(md, rq);
 		rq_completed(md, rq_data_dir(rq), false);
-		blk_mq_delay_run_hw_queue(hctx, 100/*ms*/);
+		blk_mq_delay_run_hw_queue(hctx, 500/*ms*/);
 		return BLK_MQ_RQ_QUEUE_BUSY;
 	}
 
-- 
2.12.2
