linux-kernel - Re: [PATCH] io_uring/io-wq: fix `max_workers` breakage and `nr

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Message-Id: <175796316976.265356.16431775523856266594.b4-ty@kernel.dk>
Date: Mon, 15 Sep 2025 13:06:09 -0600
From: Jens Axboe <axboe@...nel.dk>
To: Fengnan Chang <changfengnan@...edance.com>, 
 Sasha Levin <sashal@...nel.org>, Diangang Li <lidiangang@...edance.com>, 
 io-uring@...r.kernel.org, linux-kernel@...r.kernel.org, 
 Max Kellermann <max.kellermann@...os.com>
Cc: stable@...r.kernel.org
Subject: Re: [PATCH] io_uring/io-wq: fix `max_workers` breakage and
 `nr_workers` underflow


On Fri, 12 Sep 2025 02:06:09 +0200, Max Kellermann wrote:
> Commit 88e6c42e40de ("io_uring/io-wq: add check free worker before
> create new worker") reused the variable `do_create` for something
> else, abusing it for the free worker check.
> 
> This caused the value to effectively always be `true` at the time
> `nr_workers < max_workers` was checked, but it should really be
> `false`.  This means the `max_workers` setting was ignored, and worse:
> if the limit had already been reached, incrementing `nr_workers` was
> skipped even though another worker would be created.
> 
> [...]

Applied, thanks!

[1/1] io_uring/io-wq: fix `max_workers` breakage and `nr_workers` underflow
      (no commit info)

Best regards,
-- 
Jens Axboe