Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit c1d7ecf7 authored by Bart Van Assche's avatar Bart Van Assche Committed by Mike Snitzer
Browse files

dm mpath: delay requeuing while path initialization is in progress 



Requeuing a request immediately while path initialization is ongoing
causes high CPU usage, something that is undesired.  Hence delay
requeuing while path initialization is in progress.

Signed-off-by: default avatarBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 7083abbb

drivers/md/dm-mpath.c

+7 −3
Original line number Diff line number Diff line
@@ -322,13 +322,16 @@ static int __pg_init_all_paths(struct multipath *m) 
	return atomic_read(&m->pg_init_in_progress);

}



static void pg_init_all_paths(struct multipath *m)

static int pg_init_all_paths(struct multipath *m)

{

	int ret;

	unsigned long flags;



	spin_lock_irqsave(&m->lock, flags);

	__pg_init_all_paths(m);

	ret = __pg_init_all_paths(m);

	spin_unlock_irqrestore(&m->lock, flags);



	return ret;

}



static void __switch_pg(struct multipath *m, struct priority_group *pg)
@@ -503,7 +506,8 @@ static int multipath_clone_and_map(struct dm_target *ti, struct request *rq, 
		return -EIO;	/* Failed */

	} else if (test_bit(MPATHF_QUEUE_IO, &m->flags) ||

		   test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) {

		pg_init_all_paths(m);

		if (pg_init_all_paths(m))

			return DM_MAPIO_DELAY_REQUEUE;

		return DM_MAPIO_REQUEUE;

	}