From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: dm-multipath low performance with blk-mq Date: Thu, 4 Feb 2016 14:58:06 +0100 Message-ID: <56B358EE.6000007@suse.de> References: <56A8A6A8.9090003@dev.mellanox.co.il> <20160127174828.GA31802@redhat.com> <56A904B6.50407@dev.mellanox.co.il> <20160129233504.GA13661@redhat.com> <56AC79D0.5060104@suse.de> <20160130191238.GA18686@redhat.com> <56AEFF63.7050606@suse.de> <20160203180406.GA11591@redhat.com> <20160203182423.GA12913@redhat.com> <56B2F5BC.1010700@suse.de> <20160204135420.GA18227@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20160204135420.GA18227@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Mike Snitzer Cc: axboe@kernel.dk, Christoph Hellwig , Sagi Grimberg , "linux-nvme@lists.infradead.org" , "keith.busch@intel.com" , device-mapper development , linux-block@vger.kernel.org, Bart Van Assche List-Id: dm-devel.ids On 02/04/2016 02:54 PM, Mike Snitzer wrote: > On Thu, Feb 04 2016 at 1:54am -0500, > Hannes Reinecke wrote: > = [ .. ] >> But anyway, I'll be looking at your patches. > = > Thanks, sadly none of the patches are going to fix the performance > problems but I do think they are a step forward. > = Hmm. I've got a slew of patches converting dm-mpath to use atomic_t and bitops; with that we should be able to move to rcu for path lookup and do away with most of the locking. Quite raw, though; drop me a mail if you're interested. Cheers, Hannes -- = Dr. Hannes Reinecke Teamlead Storage & Networking hare@suse.de +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 N=FCrnberg GF: F. Imend=F6rffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG N=FCrnberg) From mboxrd@z Thu Jan 1 00:00:00 1970 From: hare@suse.de (Hannes Reinecke) Date: Thu, 4 Feb 2016 14:58:06 +0100 Subject: dm-multipath low performance with blk-mq In-Reply-To: <20160204135420.GA18227@redhat.com> References: <56A8A6A8.9090003@dev.mellanox.co.il> <20160127174828.GA31802@redhat.com> <56A904B6.50407@dev.mellanox.co.il> <20160129233504.GA13661@redhat.com> <56AC79D0.5060104@suse.de> <20160130191238.GA18686@redhat.com> <56AEFF63.7050606@suse.de> <20160203180406.GA11591@redhat.com> <20160203182423.GA12913@redhat.com> <56B2F5BC.1010700@suse.de> <20160204135420.GA18227@redhat.com> Message-ID: <56B358EE.6000007@suse.de> On 02/04/2016 02:54 PM, Mike Snitzer wrote: > On Thu, Feb 04 2016 at 1:54am -0500, > Hannes Reinecke wrote: > [ .. ] >> But anyway, I'll be looking at your patches. > > Thanks, sadly none of the patches are going to fix the performance > problems but I do think they are a step forward. > Hmm. I've got a slew of patches converting dm-mpath to use atomic_t and bitops; with that we should be able to move to rcu for path lookup and do away with most of the locking. Quite raw, though; drop me a mail if you're interested. Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking hare at suse.de +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 N?rnberg GF: F. Imend?rffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG N?rnberg)