Re: [PATCH 1/8] io_uring: split up io_uring_sqe into hdr + main

[Luis Chamberlain <mcgrof@kernel.org>]

On Thu, Mar 18, 2021 at 12:40:25PM -0600, Jens Axboe wrote:
> I'm not at all interested
> in having a v3 down the line as well. And I'd need to be able to do this
> seamlessly, both from an application point of view, and a performance
> point of view (no stupid conversions inline).

At this point I've now traced the history of effort of wanting to do
io-uring "ioctl" work through 3 sepearate independent efforts:

2019-12-14: Pavel Begunkov - https://lore.kernel.org/all/f77ac379ddb6a67c3ac6a9dc54430142ead07c6f.1576336565.git.asml.silence@gmail.com/
2020-11-02: Hao Xu - https://lore.kernel.org/all/1604303041-184595-1-git-send-email-haoxu@linux.alibaba.com/
2021-01-27: Kanchan Joshi - https://lore.kernel.org/linux-nvme/20210127150029.13766-1-joshi.k@samsung.com/#r

So clearly there is interest in this moving forward.

On the same day as Joshi's post you posted your file_operations based
implemenation. So that's 2 years, 2 months to this day since Pavel's
first patchset... Wouldn't we be a bit too much of a burden to ensure a
v2 will suffice for *all* use cases? If so, adaptability for evolution
sounds like a more fitting use case for design here. That way
we reduce our requirements and allow for experimentation, while
enabling improvements on future design.

  Luis