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

[Hao Xu <haoxu.linux@gmail.com>]

On 4/27/22 09:54, Jens Axboe wrote:
> Hi,
>
> I had a re-think on the flags2 addition [1] that was posted earlier
> today, and I don't really like the fact that flags2 then can't work
> with ioprio for read/write etc. We might also want to extend the
> ioprio field for other types of IO in the future.
>
> So rather than do that, do a simpler approach and just add an io_uring
> specific flag set for send/recv and friends. This then allow setting
> IORING_RECVSEND_POLL_FIRST in sqe->addr2 for those, and if set, io_uring
> will arm poll first rather than attempt a send/recv operation.
>
> [1] 
> https://lore.kernel.org/io-uring/20220426183343.150273-1-axboe@kernel.dk/
>

Hi Jens,
Could we use something like the high bits of sqe->fd to store general flags2
since I saw the number of open FDs can be about (1<<20) at most.
Though I'm not sure if we can assume the limitation of fd won't change
in the future..

Regards,
Hao