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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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Vishnu Razdan
eb1e94fee5
commit297b5ccea4upstream. create_worker_cb() reserves an io-wq worker slot only after its task-work callback runs. If the callback is canceled before then, io_worker_cancel_cb() still decrements acct->nr_workers. When an existing worker retires with its creation callback pending, that worker has already decremented the same account's worker count. The resulting undercount permits worker creation beyond the account's configured limit. On an AST2600 OpenBMC system, an unchanged sensor daemon reached 4,291 threads with the original kernel. With an equivalent downstream fix, 25 passive samples under its normal workload showed 6-9 threads. Decrement nr_workers only when the canceled callback is not create_worker_cb(). Continuation callbacks still release their reserved slot, and both callback types retain the existing running-count, reference-count, and create-state cleanup. [ Backport: retain the existing wq->lock protecting worker accounting. ] Fixes:1d5f5ea7cb("io-wq: remove worker to owner tw dependency") Cc: stable@vger.kernel.org Assisted-by: Codex:gpt-5.6-sol Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de> Link: https://patch.msgid.link/20260811-vrazdan-io-wq-b4-submit-v1-1-719ced16c921@openai.com Signed-off-by: Vishnu Razdan <vrazdan@openai.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.