On Wed, 12 Jul 2017 14:18:14 +0000 Bart Van Assche <Bart.VanAssche@xxxxxxx> wrote: > On Wed, 2017-07-12 at 09:26 +0100, John Garry wrote: > > > > What block driver controls the block device for which the performance > > > > regression > > > > has been observed? How many hardware queues were created by that block > > > > driver > > > > (see also /sys/block/*/mq/...)? > > > > Just confirming that we have only 1 queue: > > /sys/block/sdc/mq/0 as example > > Hello John, > > Can you also check the I/O scheduler that has been selected? > > Thanks, > > Bart. Hi Bart, Original numbers were with deadline-mq (not deliberately specified - so the default for this setup) To flesh them out a bit I've run the equivalent test with all the options on today's linux next. iodepth=2048, 4k blocks read only 6 disks 6 processes. SMMU disabled for now due to ongoing work to reduce it's impact. none : 716k IOPS mq-deadline : 305k IOPS kyber: 321k IOPS noop, scsi_mq disable using the kernel commandline option: 937k IOPS Thanks, Jonathan
