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| author | Bart Van Assche <bart.vanassche@sandisk.com> | 2017-04-27 10:11:16 -0700 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2017-04-27 17:08:01 -0400 |
| commit | c1d7ecf7ca11d0edd3085262c8597203440d056c (patch) | |
| tree | 670ef64efbee7a0312f21c4a2ddece23de0bba47 /drivers/md/dm-mpath.c | |
| parent | 7083abbbfc4fa706ff72d27d33a5214881979336 (diff) | |
| download | lwn-c1d7ecf7ca11d0edd3085262c8597203440d056c.tar.gz lwn-c1d7ecf7ca11d0edd3085262c8597203440d056c.zip | |
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: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-mpath.c')
| -rw-r--r-- | drivers/md/dm-mpath.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index f3c79f188747..d85baffa3377 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -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; } |