From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 16 Jan 2018 09:57:11 +0800 From: Ming Lei To: Mike Snitzer Cc: axboe@kernel.dk, Jens Axboe , linux-block@vger.kernel.org, Christoph Hellwig Subject: Re: [PATCH V4 0/3] blk-mq: issue request directly for blk_insert_cloned_request Message-ID: <20180116015710.GF3213@ming.t460p> References: <20180115165810.2515-1-ming.lei@redhat.com> <20180115174344.GA17634@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20180115174344.GA17634@redhat.com> List-ID: On Mon, Jan 15, 2018 at 12:43:44PM -0500, Mike Snitzer wrote: > On Mon, Jan 15 2018 at 11:58am -0500, > Ming Lei wrote: > > > Hi Guys, > > > > The 3 paches changes the blk-mq part of blk_insert_cloned_request(), > > in which we switch to blk_mq_try_issue_directly(), so that both dm-rq > > and blk-mq can get the dispatch result of underlying queue, and with > > this information, blk-mq can handle IO merge much better, then > > sequential I/O performance is improved much. > > > > In my dm-mpath over virtio-scsi test, this whole patchset improves > > sequential IO by 3X ~ 5X. > > > > V4: > > - remove dm patches which are in DM tree already > > - cleanup __blk_mq_issue_req as suggested by Jens > > > > Ming, > > You dropped the header cleanups that I did in v3 ("blk-mq: issue request > directly for blk_insert_cloned_request") being the one header I care > about being updated). > > I also worked in parallel on my own v4 to address Jens' dislike for v3's > 3 returns. But I skinned the cat a different way, by dropping your > first patch that introduces the __blk_mq_issue_req helper, please see > these 2 commits: > > https://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=block-4.16&id=40f8947784128bb83dc5f7a6aed7ed230222f675 > https://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=block-4.16&id=f641015f42f41df75220313ee62e8241f2feeeed > > I think it makes the changes more obvious (not spread across 2 methods > and doesn't require use of BLK_STS_AGAIN). > > Happy to yield to Jens to decide which he prefers. > > Jens, if you'd like to pick my variant of v4 up they are here, thanks! Hi Mike, Looks we were working on it at the same time, I am fine with your V4. Jens, please let us know if Mike's V4 is OK, if not, we can make V5/.., :-) Thanks, Ming