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Sat, 01 Feb 2025 07:38:43 -0800 (PST) Message-ID: <7c33ba12-2ec4-4692-b388-58950d42a0a2@kernel.dk> Date: Sat, 1 Feb 2025 08:38:42 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/8] Various io_uring micro-optimizations (reducing lock contention) To: Max Kellermann Cc: asml.silence@gmail.com, io-uring@vger.kernel.org, linux-kernel@vger.kernel.org References: <20250128133927.3989681-1-max.kellermann@ionos.com> <7f046e6e-bb9d-4e72-9683-2cdfeabf51bc@kernel.dk> Content-Language: en-US From: Jens Axboe In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 2/1/25 8:30 AM, Max Kellermann wrote: > On Sat, Feb 1, 2025 at 4:26 PM Jens Axboe 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