On Thu, Jun 11, 2020 at 01:29:07AM +0800, John Garry wrote: > Hi all, > > Here is v7 of the patchset. > > In this version of the series, we keep the shared sbitmap for driver tags, > and introduce changes to fix up the tag budgeting across request queues ( > and associated debugfs changes). > > Some performance figures: > > Using 12x SAS SSDs on hisi_sas v3 hw. mq-deadline results are included, > but it is not always an appropriate scheduler to use. > > Tag depth 4000 (default) 260** > > Baseline: > none sched: 2290K IOPS 894K > mq-deadline sched: 2341K IOPS 2313K > > Final, host_tagset=0 in LLDD* > none sched: 2289K IOPS 703K > mq-deadline sched: 2337K IOPS 2291K > > Final: > none sched: 2281K IOPS 1101K > mq-deadline sched: 2322K IOPS 1278K > > * this is relevant as this is the performance in supporting but not > enabling the feature > ** depth=260 is relevant as some point where we are regularly waiting for > tags to be available. Figures were are a bit unstable here for testing. > > A copy of the patches can be found here: > https://github.com/hisilicon/kernel-dev/commits/private-topic-blk-mq-shared-tags-rfc-v7 > > And to progress this series, we the the following to go in first, when ready: > https://lore.kernel.org/linux-scsi/20200430131904.5847-1-hare@xxxxxxx/ I'd suggest to add options to enable shared tags for null_blk & scsi_debug in V8, so that it is easier to verify the changes without real hardware. Thanks, Ming
