From: Mike Snitzer Date: Wed, 11 Mar 2015 19:01:09 +0000 (-0400) Subject: dm: add 'use_blk_mq' module param and expose in per-device ro sysfs attr X-Git-Tag: omap-for-v4.1/fixes-rc1~106^2~14 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=17e149b8f73ba116e71e25930dd6f2eb3828792d;p=pandora-kernel.git 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 --- diff --git a/Documentation/ABI/testing/sysfs-block-dm b/Documentation/ABI/testing/sysfs-block-dm index ac4b6fe245d9..f9f2339b9a0a 100644 --- a/Documentation/ABI/testing/sysfs-block-dm +++ b/Documentation/ABI/testing/sysfs-block-dm @@ -37,3 +37,11 @@ Description: Allow control over how long a request that is a accounting. This attribute is not applicable to bio-based DM devices so it will only ever report 0 for them. + +What: /sys/block/dm-/dm/use_blk_mq +Date: March 2015 +KernelVersion: 4.1 +Contact: dm-devel@redhat.com +Description: Request-based Device-mapper blk-mq I/O path mode. + Contains the value 1 if the device is using blk-mq. + Otherwise it contains 0. Read-only attribute. Reading git-diff-tree failed