Re: [PATCHSET 0/2] Add support for IORING_CQE_F_SOCK_FULL

[Pavel Begunkov <asml.silence@gmail.com>]

On 11/5/25 19:30, Jens Axboe wrote:
> Hi,
> 
> It can be useful for userspace to know if a send request had to go
> through poll to complete, as that generally means that the socket was
> out of space. On the send side, this is pretty trivial to support - we
> just need to check if the request needed to go through poll to complete.
> 
> This reuses the IORING_CQE_F_SOCK_NONEMPTY flag value, which is only
> valid for recv operations. As IORING_CQE_F_SOCK_FULL only applies on
> sends, there's no need for separate values for this flag.
> 
> Based on an earlier patchset, which utilized REQ_F_POLL_ARMED instead
> and handled patch 1 a bit differently.

FWIW, same comments as last time. REQ_F_POLL_TRIGGERED is set not
in the right place. And, with how tcp manages wait queues, you won't
be able to use it well for any throttling, as the user will get the
flagged CQE long time after, when the queue is already half empty.

-- 
Pavel Begunkov