Nicholas A. Bellinger: scsi-mq prototype discussion

July 12, 2013

Participants: Nicholas A. Bellinger, Greg KH, Hannes Reinecke, James Bottomley, Alasdair G Kergon.

People tagged: 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).

Nicholas A. Bellinger would like to discuss multi-queue SCSI implementations, such as Jens Axboe's scsi-mq work. Nicholas would like to avoid fast-path access to scsi_host->host_lock, dispatch into scsi-mq-enabled LLD code, and memory allocations. Greg KH suggested that this topic was better suited for the storage minisummit (Nicholas, Hannes, and Alasdair respectfully disagreed), and James suggested starting the discussion on the linux-scsi email list. Jens Axboe, although agreeing that the topic was a bit specialized, argued that it would be good to have at least a little technical meat on the LKS process bone. James asked for patches first, but also suggested a BoF at the Linux Plumbers Conference Storage and Filesystems Microconference. Ric Wheeler, who leads up the Plumbers Storage and Filesystems Microconference, said that he would welcome this topic, but Jens Axboe will be unable to attend Plumbers this year, which prompted Nicholas A. Bellinger to push again for a minisummit associated with LKS.