[Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion

[Nicholas A. Bellinger]

On Wed, 2013-07-17 at 04:52 +0000, James Bottomley wrote:
> On Tue, 2013-07-16 at 15:15 -0600, Jens Axboe wrote:
> > On Tue, Jul 16 2013, Nicholas A. Bellinger wrote:
> > > On Sat, 2013-07-13 at 06:53 +0000, James Bottomley wrote:

<SNIP>

> > > > 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.

That would be great, given there is a reasonable level of interest from
various parities, and the pain threshold for existing scsi small block
random I/O performance is high..

When will we know if there is a workshop / mini summit slot available..?

(CC'ing Mike Christie as well for open-iscsi/scsi-mq bits)

> 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

FYI, I'm not trying to 'sell' scsi-mq to the larger community yet, but
rather interested in getting the right scsi/block/LLD people in the same
room at KS for an hour or two to discuss implementation details, given
the scope of the effort involved.

--nab