Re: IORING_OP_POLL_ADD slower than linux-aio IOCB_CMD_POLL

[Avi Kivity <avi@scylladb.com>]

On 15/06/2022 15.21, Jens Axboe wrote:
> On 6/15/22 5:38 AM, Pavel Begunkov wrote:
>>>>> Another way is to also set IORING_SETUP_TASKRUN_FLAG, then when
>>>>> there is work that requires to enter the kernel io_uring will
>>>>> set IORING_SQ_TASKRUN in sq_flags.
>>>>> Actually, I'm not mistaken io_uring has some automagic handling
>>>>> of it internally
>>>>>
>>>>> https://github.com/axboe/liburing/blob/master/src/queue.c#L36
>>>>>
>>> Is there documentation about this flag?
>> Unfortunately, I don't see any.
>> Here is a link to the kernel commit if it helps:
>>
>> https://git.kernel.dk/cgit/linux-block/commit/?h=ef060ea9e4fd3b763e7060a3af0a258d2d5d7c0d
>>
>> I think it's more interesting what support liburing has,
>> but would need to look up in the code. Maybe Jens
>> remembers and can tell.
> It is documented, in the io_uring.2 man page in liburing:
>
> https://git.kernel.dk/cgit/liburing/tree/man/io_uring_setup.2#n200
>

Perfect. Thanks!