From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion Date: Fri, 12 Jul 2013 12:52:37 +0200 Message-ID: <51DFDFF5.80702@suse.de> References: <1373588612.7397.447.camel@haakon3.risingtidesystems.com> <20130712010223.GA15673@kroah.com> <1373592815.7397.477.camel@haakon3.risingtidesystems.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1373592815.7397.477.camel@haakon3.risingtidesystems.com> Sender: target-devel-owner@vger.kernel.org To: "Nicholas A. Bellinger" Cc: Greg KH , ksummit-2013-discuss@lists.linuxfoundation.org, Jens Axboe , James Smart , linux-scsi , LKML , James Bottomley , Andrew Vasquez , kmo@daterainc.com, target-devel , Tejun Heo , Christoph Hellwig , scameron@beardog.cce.hp.com List-Id: linux-scsi@vger.kernel.org On 07/12/2013 03:33 AM, Nicholas A. Bellinger wrote: > On Thu, 2013-07-11 at 18:02 -0700, Greg KH wrote: >> On Thu, Jul 11, 2013 at 05:23:32PM -0700, Nicholas A. Bellinger wrot= e: >>> Drilling down the work items ahead of a real mainline push is high = on >>> priority list for discussion. >>> >>> The parties to be included in such a discussion are: >>> >>> - Jens Axboe (blk-mq author) >>> - James Bottomley (scsi maintainer) >>> - Christoph Hellwig (scsi) >>> - Martin Petersen (scsi) >>> - Tejun Heo (block + libata) >>> - Hannes Reinecke (scsi error recovery) >>> - Kent Overstreet (block, per-cpu ida) >>> - Stephen Cameron (scsi-over-pcie driver) >>> - Andrew Vasquez (qla2xxx LLD) >>> - James Smart (lpfc LLD) >> >> Isn't this something that should have been discussed at the storage >> mini-summit a few months ago? >=20 > The scsi-mq prototype, along with blk-mq (in it's current form) did n= ot > exist a few short months ago. ;) >=20 >> It seems very specific to one subsystem to be a kernel summit topic= , >> don't you think? >=20 > It's no more subsystem specific than half of the other proposals so f= ar, > and given it's reach across multiple subsystems (block, scsi, target)= , > and the amount of off-list interest on the topic, I think it would ma= ke > a good candidate for discussion. >=20 And it'll open up new approaches which previously were dismissed, like re-implementing multipathing on top of scsi-mq, giving us the single scsi device like other UNIX systems. Also I do think there's quite some synergy to be had, as with blk-mq we could nail each queue to a processor, which would eliminate the need for locking. Which could be useful for other subsystems, too. Cheers, Hannes --=20 Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=C3=BCrnberg GF: J. Hawn, J. Guild, F. Imend=C3=B6rffer, HRB 16746 (AG N=C3=BCrnberg= )