Re: [PATCH liburing 0/2] Add support for IORING_SETUP_SQ_REWIND

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

On 1/24/26 15:12, Jens Axboe wrote:
> On 1/24/26 3:44 AM, Pavel Begunkov wrote:
...
>>>> The head should already be zero. Actually, sounds like the get_sqe
>>>> hunk from the patch is not needed either.
>>>
>>> Yeah agree, I think they are both false alarms. Might warrant a comment
>>> though. Or maybe we just fold it into io_uring_load_sq_head()?
>>
>> What I'm implying is that the
>>
>> +    if (!(ring->flags & IORING_SETUP_SQ_REWIND))
>> +        head = io_uring_load_sq_head(ring);
>> +
>>
>> change from the original patch for normal 64B _io_uring_get_sqe()
>> doesn't seem to be necessary. I need to take a look, but that's
>> a good thing since the function is somewhat frequently called and
>> inlined.
>>
>> That would leave __io_uring_flush_sq() to be the only place
>> checking the flag, so maybe comments would better to be put
>> there.
> 
> If you have time, would you mind checking the current repo and sending a
> patch? Looks like I messed up a bit and committed some of these bits
> with:

I'll take a look a bit later, but removing should be fine
unless liburing overwrites the sq head.

-- 
Pavel Begunkov