Re: [PATCHv2 5/5] nvme: allow user passthrough commands to poll

Kanchan Joshi
2021-05-17T16:56:13Z

On Mon, Apr 26, 2021 at 8:46 PM Keith Busch <kbusch@kernel.org> wrote:
>
> On Mon, Apr 26, 2021 at 04:43:16PM +0200, Christoph Hellwig wrote:
> > On Fri, Apr 23, 2021 at 03:05:58PM -0700, Keith Busch wrote:
> > > The block layer knows how to deal with polled requests. Let the NVMe
> > > driver use the previously reserved user "flags" fields to define an
> > > option to allocate the request from the polled hardware contexts. If
> > > polling is not enabled, then the block layer will automatically fallback
> > > to a non-polled request.
> >
> > So this only support synchronous polling for a single command. What
> > use case do we have for that? I think io_uring based polling would
> > be much more useful once we support NVMe passthrough through that.
>
> There is no significant use case here. I just needed a simple way to
> test the polled exec from earlier in the series. It was simple enough so
> I included the patch here, but it's really not important compared to the
> preceeding patches.

It would be great to see this in at some point; helps in making
passthrough more useful.
I'll look into integrating this with async-passthrough.

--
Kanchan