diff mbox

[3/7] dm-mpath: Do not lock up a CPU with requeuing activity

Message ID 20170809183216.526-4-bart.vanassche@wdc.com (mailing list archive)
State Accepted, archived
Delegated to: Mike Snitzer
Headers show

Commit Message

Bart Van Assche Aug. 9, 2017, 6:32 p.m. UTC 
When using the block layer in single queue mode, get_request()
returns ERR_PTR(-EAGAIN) if the queue is dying and the REQ_NOWAIT
flag has been passed to get_request(). Avoid that the kernel
reports soft lockup complaints in this case due to continuous
requeuing activity.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: <stable@vger.kernel.org>
---
 drivers/md/dm-mpath.c | 1 -
 1 file changed, 1 deletion(-)

Comments

Christoph Hellwig Aug. 10, 2017, 9:29 a.m. UTC | #1 
On Wed, Aug 09, 2017 at 11:32:12AM -0700, Bart Van Assche wrote:
> When using the block layer in single queue mode, get_request()
> returns ERR_PTR(-EAGAIN) if the queue is dying and the REQ_NOWAIT
> flag has been passed to get_request(). Avoid that the kernel
> reports soft lockup complaints in this case due to continuous
> requeuing activity.

Looks good,

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

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diff mbox

Patch

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 0e8ab5bb3575..0baa461eccaa 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -504,7 +504,6 @@  static int multipath_clone_and_map(struct dm_target *ti, struct request *rq,
 		if (queue_dying) {
 			atomic_inc(&m->pg_init_in_progress);
 			activate_or_offline_path(pgpath);
-			return DM_MAPIO_REQUEUE;
 		}
 		return DM_MAPIO_DELAY_REQUEUE;
 	}