Re: [PATCH 0/3] Provide more fine grained control over multipathing

[Ming Lei]

On Tue, May 29, 2018 at 09:22:40AM +0200, Johannes Thumshirn wrote:
> On Mon, May 28, 2018 at 11:02:36PM -0400, Mike Snitzer wrote:
> > No, what both Red Hat and SUSE are saying is: cool let's have a go at
> > "Plan A" but, in parallel, what harm is there in allowing "Plan B" (dm
> > multipath) to be conditionally enabled to coexist with native NVMe
> > multipath?
> 
> For a "Plan B" we can still use the global knob that's already in
> place (even if this reminds me so much about scsi-mq which at least we
> haven't turned on in fear of performance regressions).

BTW, for scsi-mq, we have made a little progress by commit 2f31115e940c
(scsi: core: introduce force_blk_mq), and virtio-scsi is working at
always scsi-mq mode now. Then driver can decide if .force_blk_mq needs
to be set.

Hope progress can be made in this nvme mpath issue too.

Thanks,
Ming