Re: [PATCH v2 0/2] async hybrid for pollable requests

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

在 2021/10/18 下午8:31, Pavel Begunkov 写道:
> On 10/18/21 11:29, Hao Xu wrote:
>> 1/2 is a prep patch. 2/2 is the main one.
>> The good thing: see commit message.
>> the side effect: for normal io-worker path, added two if and two local
>> variables. for FORCE_ASYNC path, added three if and several dereferences
>>
>> I think it is fine since the io-worker path is not the fast path, and
>> the benefit of this patchset is worth it.
> 
> We don't care about overhead in iowq, but would be better to get rid
> of the in_worker in io_read(). See comments to 1/2.
> 
> Btw, you told that it performs better comparing to normal
> IOSQE_ASYNC. I'm confused, didn't we agree that it can be
> merged into IOSQE_ASYNC without extra flags?
I said 'better than the old logic IOSQE_ASYNC logic for pollable cases'..
> 
>>
>> Btw, we need to tweak the io-cancel.c a bit, not a big problem.
>> liburing tests will come later.
>>
>> v1-->v2:
>>   - split logic of force_nonblock
>>   - tweak added code in io_wq_submit_work to reduce overhead
>>   from Pavel's commments.
>>
>> Hao Xu (2):
>>    io_uring: split logic of force_nonblock
>>    io_uring: implement async hybrid mode for pollable requests
>>
>>   fs/io_uring.c                 | 85 ++++++++++++++++++++++++++---------
>>   include/uapi/linux/io_uring.h |  4 +-
>>   2 files changed, 66 insertions(+), 23 deletions(-)
>>
>