linux-kernel - Re: [PATCH 0/4] io_uring: avoid uring_lock for IORING_SETUP_SINGLE

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Message-ID: <97fbbd68-cdd1-49fa-82d3-e3714ca70eeb@kernel.dk>
Date: Tue, 2 Sep 2025 19:28:41 -0600
From: Jens Axboe <axboe@...nel.dk>
To: Caleb Sander Mateos <csander@...estorage.com>
Cc: linux-kernel@...r.kernel.org
Subject: Re: [PATCH 0/4] io_uring: avoid uring_lock for
 IORING_SETUP_SINGLE_ISSUER

On 9/2/25 4:07 PM, Caleb Sander Mateos wrote:
> As far as I can tell, setting IORING_SETUP_SINGLE_ISSUER when creating
> an io_uring doesn't actually enable any additional optimizations (aside
> from being a requirement for IORING_SETUP_DEFER_TASKRUN).

Indeed. It was supposed to enable future optimizations, but they
didn't quite materialize.

> This series leverages IORING_SETUP_SINGLE_ISSUER's guarantee that only
> one task submits SQEs to skip taking the uring_lock mutex in the
> submission and task work paths.

Interesting, would indeed be great to kill the lock/unlock for each
submit and local work run. I'll take a closer look at this tomorrow.

-- 
Jens Axboe