Re: [PATCH] io_uring: get rid of intermediate aux cqe caches

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

On 3/1/24 03:45, Jens Axboe wrote:
> On 2/29/24 9:36 AM, Pavel Begunkov wrote:
>> With defer taskrun we store aux cqes into a cache array and then flush
>> into the CQ, and we also maintain the ordering so aux cqes are flushed
>> before request completions. Why do we need the cache instead of pushing
>> them directly? We acutally don't, so let's kill it.
>>
>> One nuance is synchronisation -- the path we touch here is only for
>> DEFER_TASKRUN and guaranteed to be executed in the task context, and
>> all cqe posting is serialised by that. We also don't need locks because
>> of that, see __io_cq_lock().
> 
> Nicely spotted! Looks good to me.

Apparently I'm wrong as "defer" in that function is not about
defer taskrun, but rather IO_URING_F_COMPLETE_DEFER. Jens, can
you drop it for now?

-- 
Pavel Begunkov