Re: [PATCH 11/11] io_uring: get rid of intermediate aux cqe caches

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

On 3/15/24 16:20, Jens Axboe wrote:
> On 3/15/24 9:30 AM, Pavel Begunkov wrote:
>> io_post_aux_cqe(), which is used for multishot requests, delays
>> completions by putting CQEs into a temporary array for the purpose
>> completion lock/flush batching.
>>
>> DEFER_TASKRUN doesn't need any locking, so for it we can put completions
>> directly into the CQ and defer post completion handling with a flag.
>> That leaves !DEFER_TASKRUN, which is not that interesting / hot for
>> multishot requests, so have conditional locking with deferred flush
>> for them.
> 
> This breaks the read-mshot test case, looking into what is going on
> there.

I forgot to mention, yes it does, the test makes odd assumptions about
overflows, IIRC it expects that the kernel allows one and only one aux
CQE to be overflown. Let me double check

-- 
Pavel Begunkov