Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
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-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
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-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
On Fri, 2013-07-19 at 21:46 +, James Bottomley wrote: > On Fri, 2013-07-19 at 14:22 -0700, Nicholas A. Bellinger wrote: > > On Wed, 2013-07-17 at 04:52 +, 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 +, James Bottomley wrote: > > > > > > > > > > > > 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. > > Well, so that's why I think plumbers might be a better venue: we'll have > more of the actual storage people there. Usually we get at most 2-3 > storage people to KS compared to the 25 or so we usually have at LSF ... > that makes KS not a very good venue for storage centric discussions. > The most relevant people for the discussion are Jens, Hannes, Christoph, Tejun, Martin, Mike, and you. I know these folks are regular attendees for KS, but typically not for plumbers, which is why I made this KS topic proposal in the first place. --nab -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
On Fri, 2013-07-19 at 14:22 -0700, Nicholas A. Bellinger wrote: > On Wed, 2013-07-17 at 04:52 +, 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 +, James Bottomley wrote: > > > > > > > > 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. Well, so that's why I think plumbers might be a better venue: we'll have more of the actual storage people there. Usually we get at most 2-3 storage people to KS compared to the 25 or so we usually have at LSF ... that makes KS not a very good venue for storage centric discussions. James -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
On Wed, 2013-07-17 at 04:52 +, 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 +, James Bottomley wrote: > > > > 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
On 07/17/2013 12:52 AM, 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 +, James Bottomley wrote: On Fri, 2013-07-12 at 12:52 +0200, Hannes Reinecke wrote: 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 wrote: 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? 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 Ric -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
On 07/17/2013 12:52 AM, 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 +, James Bottomley wrote: On Fri, 2013-07-12 at 12:52 +0200, Hannes Reinecke wrote: 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 wrote: 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? 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 Ric -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
On Wed, 2013-07-17 at 04:52 +, 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 +, 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 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
On Fri, 2013-07-19 at 14:22 -0700, Nicholas A. Bellinger wrote: On Wed, 2013-07-17 at 04:52 +, 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 +, 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. Well, so that's why I think plumbers might be a better venue: we'll have more of the actual storage people there. Usually we get at most 2-3 storage people to KS compared to the 25 or so we usually have at LSF ... that makes KS not a very good venue for storage centric discussions. James -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
On Fri, 2013-07-19 at 21:46 +, James Bottomley wrote: On Fri, 2013-07-19 at 14:22 -0700, Nicholas A. Bellinger wrote: On Wed, 2013-07-17 at 04:52 +, 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 +, 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. Well, so that's why I think plumbers might be a better venue: we'll have more of the actual storage people there. Usually we get at most 2-3 storage people to KS compared to the 25 or so we usually have at LSF ... that makes KS not a very good venue for storage centric discussions. The most relevant people for the discussion are Jens, Hannes, Christoph, Tejun, Martin, Mike, and you. I know these folks are regular attendees for KS, but typically not for plumbers, which is why I made this KS topic proposal in the first place. --nab -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
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 +, James Bottomley wrote: > > > On Fri, 2013-07-12 at 12:52 +0200, Hannes Reinecke wrote: > > > > 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 > > > > >> wrote: > > > > >>> 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? > > > > > > > > > > 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
On Tue, Jul 16, 2013 at 02:07:29PM -0700, Nicholas A. Bellinger wrote: > On Sat, 2013-07-13 at 06:53 +, James Bottomley wrote: > > On Fri, 2013-07-12 at 12:52 +0200, Hannes Reinecke wrote: > > > 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 wrote: > > > >>> 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? > > > > > > > > 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. I'd be very interested in attending this, if invited. -- steve -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
On Tue, Jul 16 2013, Nicholas A. Bellinger wrote: > On Sat, 2013-07-13 at 06:53 +, James Bottomley wrote: > > On Fri, 2013-07-12 at 12:52 +0200, Hannes Reinecke wrote: > > > 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 wrote: > > > >>> 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? > > > > > > > > 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. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
On Sat, 2013-07-13 at 06:53 +, James Bottomley wrote: > On Fri, 2013-07-12 at 12:52 +0200, Hannes Reinecke wrote: > > 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 wrote: > > >>> 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? > > > > > > 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. --nab -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
On Sat, 2013-07-13 at 06:53 +, James Bottomley wrote: On Fri, 2013-07-12 at 12:52 +0200, Hannes Reinecke wrote: 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 wrote: 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? 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. --nab -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
On Tue, Jul 16 2013, Nicholas A. Bellinger wrote: On Sat, 2013-07-13 at 06:53 +, James Bottomley wrote: On Fri, 2013-07-12 at 12:52 +0200, Hannes Reinecke wrote: 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 wrote: 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? 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. -- Jens Axboe -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
On Tue, Jul 16, 2013 at 02:07:29PM -0700, Nicholas A. Bellinger wrote: On Sat, 2013-07-13 at 06:53 +, James Bottomley wrote: On Fri, 2013-07-12 at 12:52 +0200, Hannes Reinecke wrote: 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 wrote: 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? 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. I'd be very interested in attending this, if invited. -- steve -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
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 +, James Bottomley wrote: On Fri, 2013-07-12 at 12:52 +0200, Hannes Reinecke wrote: 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 wrote: 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? 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 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
On Fri, 2013-07-12 at 12:52 +0200, Hannes Reinecke wrote: > 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 wrote: > >>> 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? > > > > 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 ... James -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
On Fri, 2013-07-12 at 12:52 +0200, Hannes Reinecke wrote: 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 wrote: 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? 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 ... James -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
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 wrote: >>> 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? > > 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. Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage h...@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
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 wrote: 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? 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. Cheers, Hannes -- Dr. Hannes Reinecke zSeries Storage h...@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg) -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
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 wrote: > > 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? 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. Thanks, --nab -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
On Thu, Jul 11, 2013 at 05:23:32PM -0700, Nicholas A. Bellinger wrote: > 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? It seems very specific to one subsystem to be a kernel summit topic, don't you think? thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
On Thu, Jul 11, 2013 at 05:23:32PM -0700, Nicholas A. Bellinger wrote: 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? It seems very specific to one subsystem to be a kernel summit topic, don't you think? thanks, greg k-h -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [Ksummit-2013-discuss] [ATTEND] scsi-mq prototype discussion
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 wrote: 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? 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. Thanks, --nab -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
