Re: [LSF/MM/BPF TOPIC] dmabuf backed read/write

Jason Gunthorpe
2026-02-09T13:24:30Z

On Mon, Feb 09, 2026 at 02:09:24PM +0100, Christian König wrote:

> We have exercised and discussed this in absolutely detail and it is
> not going to fly anywhere.

Yes, I understand you concerns with struct page from past abuses.

> The struct page based approach in fundamentally incompatible with
> driver managed exporters.

The *general* struct page system is incompatible - but that is not
what I'm suggesting. I'm suggesting io_uring, and only io_uring could
use this with it fully implementing all the lifecycle rules that are
needed. Including move_notify and fences so that the driver managed
exporter has no issue.

Reworking the block stack to not rely on page is also a good path, but
probably alot harder. :\

Jason