Re: [PATCH 1/3] net: Remove support for AIO on sockets

[Jens Axboe]

On 5/27/26 2:13 AM, Christoph Hellwig wrote:
> On Tue, May 26, 2026 at 09:58:27AM -0600, Jens Axboe wrote:
>>> The current TCP zerocopy implementation provides completion notification
>>> through the socket error code, which is freaking weird and doesn't
>>> integrate well with either io_uring or in-kernel callers.
>>
>> We already have that via io_uring
> 
> Where?  And how do make that available to in-kernel users like
> storage protocols and network file system, which really suffer from
> the current MSG_SPLICE_PAGES semantics.

For zero copy, on both the receive and send side. Since we have a proper
notification channel, that's what we use rather than the hack that is
the error queue.

>> , and without needing msg_kiocb or the
> 
> What do you think is the downside of using a kiocb here like for
> everything else with async notifications?

Where would the notifications go? You'd end up inventing something new
to propagate them to userspace then. The io_uring side does not rely on
using msg_kiocb, and iirc that part was only ever used for the crypto
stuff and largely broken. Which is why I do agree with just yanking it
out.

-- 
Jens Axboe