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

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

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..

> Though I'm not sure if we can assume the limitation of fd won't change
> in the future..
> 
> Regards,
> Hao
> 
>