From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Subject: Re: [PATCH v3 0/8] dm: add request-based blk-mq support Date: Wed, 17 Dec 2014 17:51:44 -0500 Message-ID: <20141217225143.GB15390@redhat.com> References: <1418788804-1982-1-git-send-email-snitzer@redhat.com> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Keith Busch Cc: axboe@kernel.dk, bvanassche@acm.org, hch@infradead.org, dm-devel@redhat.com, j-nomura@ce.jp.nec.com List-Id: dm-devel.ids On Wed, Dec 17 2014 at 4:42pm -0500, Keith Busch wrote: > On Tue, 16 Dec 2014, Mike Snitzer wrote: > >Here is v3 of the request-based DM blk-support patchset. I've also > >published a git repo here: > >https://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/log/?h=dm-for-3.20-blk-mq > > > >I found quite a few issues with v2 for both blk-mq and old > >request-based DM. I've still attributed the original patches from > >Keith to him even though I fixed/rewrote significant portions. Keith, > >I'm happy to leave attribution like this unless you'd prefer I change > >it. > > Thanks a bunch, Mike! I'll need to merge your tree with Jens' for nvme > blk-mq, and one patch for a nvme scsi translation fix, then I can test > this out. I get my dual ported nvme controller back tomorrow, so should > have results before the end of the week. No problem. Please test with the latest 'dm-for-3.20-blk-mq' -- topmost commit should be 1943bd21bf8df061b3112c945160e2a740a906ba I don't have any dual ported NVMe hardware or anything so I haven't _really_ tested all aspects of this code. I've mainly studied the code _a lot_ and made sure that basic IO is getting submitted/completed as expected (for both the old and blk-mq cases). I'll be interested to understand if these changes are sufficient for your hardware.. I'm left wondering how/if scsi-mq should fit into dm-multipath given that I know iSER is at least slated to use scsi-mq. Also, we have the scsi_dh layer that obviously isn't in the mix here with direct submission and completion with the blk-mq driver. > I'm happy to take credit, but if your rewrite is sufficiently different, > I'm okay to just append a Tested-by once that's done. :) It is pretty different in that I'm maintaining both the old and blk-mq paths in DM core's request-based path. But your v2 series provided a roadmap for what was needed for the blk-mq path... so you'll still find your code for sure. I'd say the 8th patch is what saw the biggest rewrite so I can go ahead and flip that to be attributed to me if you'd rather not get all the blame ;) Mike