Re: [PATCH v15 7/9] nvmet-passthru: Add passthru code to process commands

[Keith Busch]

On Mon, Jul 20, 2020 at 04:28:26PM -0700, Sagi Grimberg wrote:
> On 7/20/20 4:17 PM, Keith Busch wrote:
> > On Mon, Jul 20, 2020 at 05:01:19PM -0600, Logan Gunthorpe wrote:
> > > On 2020-07-20 4:35 p.m., Sagi Grimberg wrote:
> > > 
> > > > passthru commands are in essence REQ_OP_DRV_IN/REQ_OP_DRV_OUT, which
> > > > means that the driver shouldn't need the ns at all. So if you have a
> > > > dedicated request queue (mapped to the I/O tagset), you don't need the
> > > > ns->queue and we can lose the ns lookup altogether.
> > 
> > We still need a request_queue to dispatch the command. I guess you could
> > make a generic one for the controller that isn't tied to a namespace,
> > but we lose the fair shared tag allocation.
> 
> What do you mean fair shared tag allocation?

See hctx_may_queue().