Re: [RFC 3/3] io_uring: try to batch poll request completion

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

在 2021/9/23 上午1:01, Hao Xu 写道:
> 在 2021/9/23 上午1:00, Hao Xu 写道:
>> 在 2021/9/22 下午8:34, Xiaoguang Wang 写道:
>>> For an echo-server based on io_uring's IORING_POLL_ADD_MULTI feature,
>>> only poll request are completed in task work, normal read/write
>>> requests are issued when user app sees cqes on corresponding poll
>>> requests, and they will mostly read/write data successfully, which
>>> don't need task work. So at least for echo-server model, batching
>>> poll request completion properly will give benefits.
>>>
>>> Currently don't find any appropriate place to store batched poll
>>> requests, put them in struct io_submit_state temporarily, which I
>>> think it'll need rework in future.
>>>
>>> Signed-off-by: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
>> We may need flush completion when io_submit_end as well, there may be
>> situations where pure poll reqs are sparse. For instance, users may
>> just use pure poll to do accept, and fast poll for read/write,
> I mean in persistent connection model.
>> send/recv, latency for pure poll reqs may amplify.
I actually think flush them in io_subimit_state_end doesn't work as well
since it is multishot req..