On Tue, Apr 4, 2017 at 8:07 PM, Hannes Reinecke <hare@xxxxxxx> wrote: > Hi all, > > as discussed recently most existing HBAs have a host-wide tagset which > does not map easily onto the per-queue tagset model of block mq. > This patchset implements a flag BLK_MQ_F_GLOBAL_TAGS for block-mq, which > enables the use of a shared tagset for all hardware queues. > The second patch adds a flag 'host_tagset' to the SCSI host template, > which allows drivers to enable the use of the global tagset. > > This patchset probably has some performance implications as > there is a quite high probability of cache-bouncing when allocating > tags. Also I'm not quite sure if the implemented tagset sharing > is the correct way to handle things. > So this can be considered an RFC. > > As usual, comments and reviews are welcome. Just be curious, why is multi hard queue used for this case? Are there some real cases in SCSI? Thanks, Ming Lei
