Re: [PATCH bpf-next v1 1/8] io_uring: Implement eBPF iterator for registered buffers

[Kumar Kartikeya Dwivedi <memxor@gmail.com>]

On Fri, Nov 19, 2021 at 10:26:59AM IST, Alexei Starovoitov wrote:
> On Fri, Nov 19, 2021 at 09:45:23AM +0530, Kumar Kartikeya Dwivedi wrote:
> >
> > Also, this work is part of GSoC. There is already code that is waiting for this
> > to fill in the missing pieces [0]. If you want me to add a sample/selftest that
> > demonstrates/tests how this can be used to reconstruct a task's io_uring, I can
> > certainly do that. We've already spent a few months contemplating on a few
> > approaches and this turned out to be the best/most powerful. At one point I had
> > to scrap some my earlier patches completely because they couldn't work with
> > descriptorless io_uring. Iterator seem like the best solution so far that can
> > adapt gracefully to feature additions in something seeing as heavy development
> > as io_uring.
> >
> >   [0]: https://github.com/checkpoint-restore/criu/commit/cfa3f405d522334076fc4d687bd077bee3186ccf#diff-d2cfa5a05213c854d539de003a23a286311ae81431026d3d50b0068c0cb5a852
> >   [1]: https://github.com/checkpoint-restore/criu/pull/1597
>
> Is that the main PR? 1095 changed files? Is it stale or something?
> Is there a way to view the actual logic that exercises these bpf iterators?

No, there is no code exercising BPF iterator in that PR yet (since it wouldn't
build/run in CI). There's some code I have locally that uses these to collect
the necessary information, I can post that, either as a sample or selftest in
the next version, or separately on GH for you to take a look.

I still rebased it so that you can see the rest of the actual code.

--
Kartikeya