From: Mike Snitzer Date: Wed, 11 Mar 2015 03:49:26 +0000 (-0400) Subject: dm: optimize dm_mq_queue_rq to _not_ use kthread if using pure blk-mq X-Git-Tag: omap-for-v4.1/fixes-rc1~106^2~15 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=022333427a;p=pandora-kernel.git dm: optimize dm_mq_queue_rq to _not_ use kthread if using pure blk-mq dm_mq_queue_rq() is in atomic context so care must be taken to not sleep -- as such GFP_ATOMIC is used for the md->bs bioset allocations and dm-mpath's call to blk_get_request(). In the future the bioset allocations will hopefully go away (by removing support for partial completions of bios in a cloned request). Also prepare for supporting DM blk-mq ontop of old-style request_fn device(s) if a new dm-mod 'use_blk_mq' parameter is set. The kthread will still be used to queue work if blk-mq is used ontop of old-style request_fn device(s). Signed-off-by: Mike Snitzer --- Reading git-diff-tree failed