On Fri, Jul 19 2013, Ric Wheeler wrote: > 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? > >>>>>>The scsi-mq prototype, along with blk-mq (in it's current form) did not > >>>>>>exist a few short months ago. ;) > >>>>>> > >>>>>>> It seems very specific to one subsystem to be a kernel summit topic, > >>>>>>>don't you think? > >>>>>>It's no more subsystem specific than half of the other proposals so far, > >>>>>>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 make > >>>>>>a good candidate for discussion. > >>>>>> > >>>>>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. > >>>>Lets start with discussing this on the list, please, and then see where > >>>>we go from there ... > >>>> > >>>Yes, the discussion is beginning to make it's way to the list. I've > >>>mostly been waiting for blk-mq to get a wider review before taking the > >>>early scsi-mq prototype driver to a larger public audience. > >>> > >>>Primarily, I'm now reaching out to the people most effected by existing > >>>scsi_request_fn() based performance limitations. Most of them have > >>>abandoned existing scsi_request_fn() based logic in favor of raw block > >>>make_request() based drivers, and are now estimating the amount of > >>>effort to move to an scsi-mq based approach. > >>> > >>>Regardless, as the prototype progresses over the next months, having a > >>>face-to-face discussion with the key parties in the room would be very > >>>helpful given the large amount of effort involved to actually make this > >>>type of generational shift in SCSI actually happen. > >>There's a certain amount of overlap with the aio/O_DIRECT work as well. > >>But if it's not a general session, could always be a BOF or something. > >> > >>I'll second the argument that most technical topics probably DO belong > >>in a topic related workshop. But that leaves us with basically only > >>process related topics at KS, I don't think it hurts to have a bit of > >>tech meat on the bone too. At least I personally miss that part of KS > >>from years gone by. > >Heh well, given that most of the block mq discussions at LSF have been > >you saying you really should get around to cleaning up and posting the > >code, you'll understand my wanting to see that happen first ... > > > >I suppose we could try to run a storage workshop within KS, but I think > >most of the mini summit slots have already gone. There's also plumbers > >if all slots are gone (I would say that, being biased and on the > >programme committee) Ric is running the storage and Filesystems MC > > > >http://www.linuxplumbersconf.org/2013/ocw/events/LPC2013/tracks/159 > > > >James > > > > And we still are looking for suggested topics - it would be great to have > the multi-queue work at plumbers. > > You can post a proposal for it (or other topics) here: > > http://www.linuxplumbersconf.org/2013/ocw/events/LPC2013/proposals FWIW, I can't make Plumbers this year, unfortunately. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
