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authorMike Snitzer <snitzer@redhat.com>2015-03-08 00:51:47 -0500
committerMike Snitzer <snitzer@redhat.com>2015-04-15 12:10:16 -0400
commitbfebd1cdb497a57757c83f5fbf1a29931591e2a4 (patch)
treec4ca9675ad22a45eb6e36b130db0d65d574dd2b3 /include/uapi
parent0ce65797a77ee780f62909d3128bf08b9735718b (diff)
downloadop-kernel-dev-bfebd1cdb497a57757c83f5fbf1a29931591e2a4.zip
op-kernel-dev-bfebd1cdb497a57757c83f5fbf1a29931591e2a4.tar.gz
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 'include/uapi')
-rw-r--r--include/uapi/linux/dm-ioctl.h4
1 files changed, 2 insertions, 2 deletions
diff --git a/include/uapi/linux/dm-ioctl.h b/include/uapi/linux/dm-ioctl.h
index 889f3a5..eac8c36 100644
--- a/include/uapi/linux/dm-ioctl.h
+++ b/include/uapi/linux/dm-ioctl.h
@@ -267,9 +267,9 @@ enum {
#define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)
#define DM_VERSION_MAJOR 4
-#define DM_VERSION_MINOR 30
+#define DM_VERSION_MINOR 31
#define DM_VERSION_PATCHLEVEL 0
-#define DM_VERSION_EXTRA "-ioctl (2014-12-22)"
+#define DM_VERSION_EXTRA "-ioctl (2015-3-12)"
/* Status bits */
#define DM_READONLY_FLAG (1 << 0) /* In/Out */
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