On Mon, Jul 02, 2018 at 02:56:52PM +0200, Johannes Thumshirn wrote: > On Mon, Jul 02, 2018 at 05:54:22AM -0700, Christoph Hellwig wrote: > > On Mon, Jul 02, 2018 at 01:06:42PM +0800, Ming Lei wrote: > > > With the introduced module parameter of 'use_blk_mq', it is easy > > > to switch between 'blk_mq' and 'non_blk_mq' by reloading scsi_debug > > > module, so that we can test scsi_mq/blk_mq related regressions easily. > > > > No. We should not make a per driver choice. > > Btw, wouldn't it be time for: > > diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig > index 35c909bbf8ba..bd115bab162e 100644 > --- a/drivers/scsi/Kconfig > +++ b/drivers/scsi/Kconfig > @@ -49,6 +49,7 @@ config SCSI_NETLINK > > config SCSI_MQ_DEFAULT > bool "SCSI: use blk-mq I/O path by default" > + default y > depends on SCSI > ---help--- > This option enables the new blk-mq based I/O path for SCSI > > again and see how we've improved in the last year and a half? Yes, totally. We'll just need to sort out the error handling with scsi and mq first (for 4.18 in fact).