Re: [PATCH 0/8] Various io_uring micro-optimizations (reducing lock contention)
From: Jens Axboe
Date: Sat Feb 01 2025 - 10:38:53 EST
On 2/1/25 8:30 AM, Max Kellermann wrote:
> On Sat, Feb 1, 2025 at 4:26 PM Jens Axboe <axboe@xxxxxxxxx> wrote:
>>> Not a huge fan of adding more epoll logic to io_uring, but you are right
>>> this case may indeed make sense as it allows you to integrate better
>>> that way in existing event loops. I'll take a look.
>>
>> Here's a series doing that:
>>
>> https://git.kernel.dk/cgit/linux/log/?h=io_uring-epoll-wait
>>
>> Could actually work pretty well - the last patch adds multishot support
>> as well, which means we can avoid the write lock dance for repeated
>> triggers of this epoll event. That should actually end up being more
>> efficient than regular epoll_wait(2).
>
> Nice, thanks Jens! I will integrate this in our I/O event loop and
> test it next week. This will eliminate the io_uring poll wakeup
> overhead completely.
That'd be great, let us know how it goes!
--
Jens Axboe