From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Subject: Re: [PATCHv2 0/4] blk-mq support for dm multipath Date: Fri, 5 Dec 2014 19:35:18 -0500 Message-ID: <20141206003518.GA1733@redhat.com> References: <1413589598-17631-1-git-send-email-keith.busch@intel.com> <20141028182627.GA28537@redhat.com> <20141205232542.GA1274@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: Christoph Hellwig , Jun'ichi Nomura , dm-devel@redhat.com List-Id: dm-devel.ids On Fri, Dec 05 2014 at 6:33pm -0500, Keith Busch wrote: > On Fri, 5 Dec 2014, Mike Snitzer wrote: > >Hi Keith, > > > >I've found a few issues with your v2. I've been working through the > >code and fixing things as I see them. Please see this branch: > >https://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/log/?h=dm-for-3.19-blk-mq > > > >My changes build on your v2 baseline. > > > >How much testing have you done? It could be that my changes screwed > >something up but... I just tried simply creating a normal request-based > >DM multipath device (using non blk-mq devices) and hit this crash: > > Thanks, Mike. I'll take a look at your fixes next week. > > I only tested on nvme blk-mq. I don't have any SCSI devices to try, > but I _really_ need to get one if I'm serious about making this work, > so I'll find something next week as well. I'll continue review to see if I can sort out why we're getting this crash. FYI, you don't _need_ real SCSI devices to test dm-multipath. Easy enough to just use scsi_debug so long as you have free memory: modprobe scsi_debug dev_size_mb=100 num_tgts=1 vpd_use_hostno=0 add_host=4 add_host makes multiple paths vpd_use_hostno=0 makes sure that all paths will have the same wwid