Re: [PATCH 17/17] nvme: enable non-inline passthru commands

Kanchan Joshi
2022-04-01T02:34:24Z

On Fri, Apr 1, 2022 at 6:55 AM Jens Axboe <axboe@kernel.dk> wrote:
>
> On 3/30/22 7:14 AM, Kanchan Joshi wrote:
> > On Wed, Mar 30, 2022 at 6:32 PM Christoph Hellwig <hch@lst.de> wrote:
> >>
> >> On Fri, Mar 25, 2022 at 07:09:21PM +0530, Kanchan Joshi wrote:
> >>> Ok. If you are open to take new opcode/struct route, that is all we
> >>> require to pair with big-sqe and have this sorted. How about this -
> >>
> >> I would much, much, much prefer to support a bigger CQE. Having
> >> a pointer in there just creates a fair amount of overhead and
> >> really does not fit into the model nvme and io_uring use.
> >
> > Sure, will post the code with bigger-cqe first.
>
> I can add the support, should be pretty trivial. And do the liburing
> side as well, so we have a sane base.

I will post the big-cqe based work today. It works with fio.
It does not deal with liburing (which seems tricky), but hopefully it
can help us move forward anyway .

> Then I'd suggest to collapse a few of the patches in the series,
> the ones that simply modify or fix gaps in previous ones. Order
> the series so we build the support and then add nvme support
> nicely on top of that.

I think we already did away with patches which were fixing only the
gaps. But yes, patches still add infra for features incrementally.
Do you mean having all io_uring infra (async, plug, poll) squashed
into a single io_uring patch?
On a related note, I was thinking of deferring fixed-buffer and
bio-cache support for now.