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

[Jens Axboe <axboe@kernel.dk>]

On 4/29/22 12:40 PM, Hao Xu wrote:
> 
> 
> On 4/30/22 02:31, Hao Xu wrote:
>> 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.
> 
> oops, sorry my bad, (1<<20) is just a default value..

Indeed, you can certainly go higher and people do.

-- 
Jens Axboe