From 17e149b8f73ba116e71e25930dd6f2eb3828792d Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Wed, 11 Mar 2015 15:01:09 -0400 Subject: dm: add 'use_blk_mq' module param and expose in per-device ro sysfs attr Request-based DM's blk-mq support defaults to off; but a user can easily change the default using the dm_mod.use_blk_mq module/boot option. Also, you can check what mode a given request-based DM device is using with: cat /sys/block/dm-X/dm/use_blk_mq This change enabled further cleanup and reduced work (e.g. the md->io_pool and md->rq_pool isn't created if using blk-mq). Signed-off-by: Mike Snitzer --- drivers/md/dm-sysfs.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'drivers/md/dm-sysfs.c') diff --git a/drivers/md/dm-sysfs.c b/drivers/md/dm-sysfs.c index f5bb3944f75e..7e818f5f1dc4 100644 --- a/drivers/md/dm-sysfs.c +++ b/drivers/md/dm-sysfs.c @@ -89,15 +89,24 @@ static ssize_t dm_attr_suspended_show(struct mapped_device *md, char *buf) return strlen(buf); } +static ssize_t dm_attr_use_blk_mq_show(struct mapped_device *md, char *buf) +{ + sprintf(buf, "%d\n", dm_use_blk_mq(md)); + + return strlen(buf); +} + static DM_ATTR_RO(name); static DM_ATTR_RO(uuid); static DM_ATTR_RO(suspended); +static DM_ATTR_RO(use_blk_mq); static DM_ATTR_RW(rq_based_seq_io_merge_deadline); static struct attribute *dm_attrs[] = { &dm_attr_name.attr, &dm_attr_uuid.attr, &dm_attr_suspended.attr, + &dm_attr_use_blk_mq.attr, &dm_attr_rq_based_seq_io_merge_deadline.attr, NULL, }; -- cgit v1.2.3-70-g09d2