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authorMike Snitzer <snitzer@redhat.com>2015-03-08 06:51:47 +0100
committerMike Snitzer <snitzer@redhat.com>2015-04-15 18:10:16 +0200
commitbfebd1cdb497a57757c83f5fbf1a29931591e2a4 (patch)
treec4ca9675ad22a45eb6e36b130db0d65d574dd2b3 /drivers/md/dm-mpath.c
parentdm: impose configurable deadline for dm_request_fn's merge heuristic (diff)
downloadlinux-bfebd1cdb497a57757c83f5fbf1a29931591e2a4.tar.xz
linux-bfebd1cdb497a57757c83f5fbf1a29931591e2a4.zip
dm: add full blk-mq support to request-based DM
Commit e5863d9ad ("dm: allocate requests in target when stacking on blk-mq devices") served as the first step toward fully utilizing blk-mq in request-based DM -- it enabled stacking an old-style (request_fn) request_queue ontop of the underlying blk-mq device(s). That first step didn't improve performance of DM multipath ontop of fast blk-mq devices (e.g. NVMe) because the top-level old-style request_queue was severely limited by the queue_lock. The second step offered here enables stacking a blk-mq request_queue ontop of the underlying blk-mq device(s). This unlocks significant performance gains on fast blk-mq devices, Keith Busch tested on his NVMe testbed and offered this really positive news: "Just providing a performance update. All my fio tests are getting roughly equal performance whether accessed through the raw block device or the multipath device mapper (~470k IOPS). I could only push ~20% of the raw iops through dm before this conversion, so this latest tree is looking really solid from a performance standpoint." Signed-off-by: Mike Snitzer <snitzer@redhat.com> Tested-by: Keith Busch <keith.busch@intel.com>
Diffstat (limited to 'drivers/md/dm-mpath.c')
-rw-r--r--drivers/md/dm-mpath.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index add6391f3f8e..c8f07e5a9a17 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -1703,7 +1703,7 @@ out:
*---------------------------------------------------------------*/
static struct target_type multipath_target = {
.name = "multipath",
- .version = {1, 8, 0},
+ .version = {1, 9, 0},
.module = THIS_MODULE,
.ctr = multipath_ctr,
.dtr = multipath_dtr,