Commit a5b9afd6 authored by Bart Van Assche's avatar Bart Van Assche Committed by Greg Kroah-Hartman

dm mpath: delay requeuing while path initialization is in progress

commit c1d7ecf7 upstream.

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>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 5087ded2
......@@ -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;
}
......
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