Re: [PATCH net-next v10 02/14] net: page_pool: create hooks for custom page providers

Mina Almasry
2024-06-10T15:41:41Z

On Mon, Jun 10, 2024 at 5:38 AM Christian König
<christian.koenig@amd.com> wrote:
>
> Am 10.06.24 um 14:16 schrieb Jason Gunthorpe:
> > On Mon, Jun 10, 2024 at 02:07:01AM +0100, Pavel Begunkov wrote:
> >> On 6/10/24 01:37, David Wei wrote:
> >>> On 2024-06-07 17:52, Jason Gunthorpe wrote:
> >>>> IMHO it seems to compose poorly if you can only use the io_uring
> >>>> lifecycle model with io_uring registered memory, and not with DMABUF
> >>>> memory registered through Mina's mechanism.
> >>> By this, do you mean io_uring must be exclusively used to use this
> >>> feature?
> >>>
> >>> And you'd rather see the two decoupled, so userspace can register w/ say
> >>> dmabuf then pass it to io_uring?
> >> Personally, I have no clue what Jason means. You can just as
> >> well say that it's poorly composable that write(2) to a disk
> >> cannot post a completion into a XDP ring, or a netlink socket,
> >> or io_uring's main completion queue, or name any other API.
> > There is no reason you shouldn't be able to use your fast io_uring
> > completion and lifecycle flow with DMABUF backed memory. Those are not
> > widly different things and there is good reason they should work
> > together.
>
> Well there is the fundamental problem that you can't use io_uring to
> implement the semantics necessary for a dma_fence.
>
> That's why we had to reject the io_uring work on DMA-buf sharing from
> Google a few years ago.
>

Any chance someone can link me to this? io_uring, as far as my
primitive understanding goes, is not yet very adopted at Google, and
I'm curious what this effort is.

--
Thanks,
Mina