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From: Petr Mladek <pmladek@suse.com>
To: Jia He <justin.he@arm.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>,
	Kees Cook <kees@kernel.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] lib/tests: test_ratelimit: fix stress test thread lifecycle and leak
Date: Thu, 25 Jun 2026 13:40:31 +0200	[thread overview]
Message-ID: <aj0Tr2wrMkk9FIJu@pathway.suse.cz> (raw)
In-Reply-To: <20260529085855.1810870-1-justin.he@arm.com>

On Fri 2026-05-29 08:58:55, Jia He wrote:
> The stress test's WARN_ON_ONCE(!sktp->tp) check in the child thread is
> racy and unnecessary: since kthread_run() wakes the thread before
> returning, the child can run before sktp[i].tp has been assigned.
> Moreover, sktp->tp is never actually used in the child function, so the
> check serves no purpose. Remove it and keep the original kthread_run()
> 
> Also add a common cleanup path for thread creation failures. If creating
> one of the later threads fails, stop all threads that were already
> started and free the allocated array instead of leaving orphan kthreads
> and leaked memory behind.
> 
> Finally, replace the module-static doneflag with kthread_should_stop().
> With the doneflag, child threads may exit before the parent calls
> kthread_stop(), so the task lifetime is no longer guaranteed when the
> parent later tries to stop them. Using kthread_should_stop() keeps each
> child alive until kthread_stop() synchronously terminates it.
> 
> Suggested-by: Petr Mladek <pmladek@suse.com>
> Signed-off-by: Jia He <justin.he@arm.com>

JFYI, the patch has been committed into printk/linux.git,
branch for-7.3.

Best Regards,
Petr

PS: I have already sent pull request for 7.2. And this is
    not serious enough to trigger another one.

      parent reply	other threads:[~2026-06-25 11:40 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-29  8:58 Jia He
2026-06-24 15:12 ` Petr Mladek
2026-06-24 16:14   ` Paul E. McKenney
2026-06-25 11:40 ` Petr Mladek [this message]

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