On Tue, 2017-04-04 at 08:32 -0700, Omar Sandoval wrote: > blk-mq already supports a shared tagset, and scsi-mq already uses that. > When we initialize a request queue, we add it to a tagset with > blk_mq_add_queue_set(), where we automatically mark the tagset as shared > if there is more than one queue using it. What does this do that > BLK_MQ_F_TAG_SHARED doesn't cover? Hello Omar, Today blk-mq creates one tag set per hardware queue. The sharing by scsi-mq is between request queues for hardware queues that have the same index but not between hardware queues of a single request queue. My understanding is that the goal of this patch series is to make it possible to use a single tag set for all hardware queues and all request queues that share the same SCSI host. Bart.
