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Date: Tue, 17 Jul 2018 12:34:34 -0700
From: isaacm@codeaurora.org
To: Peter Zijlstra <peterz@infradead.org>
Cc: matt@codeblueprint.co.uk, mingo@kernel.org, tglx@linutronix.de,
        bigeasy@linutronix.de, linux-kernel@vger.kernel.org,
        psodagud@codeaurora.org, gregkh@linuxfoundation.org,
        pkondeti@codeaurora.org, stable@vger.kernel.org
Subject: Re: [PATCH v4] stop_machine: Disable preemption after queueing
 stopper threads
In-Reply-To: <20180717183450.GL2494@hirez.programming.kicks-ass.net>
References: <1531845017-19935-1-git-send-email-isaacm@codeaurora.org>
 <20180717183450.GL2494@hirez.programming.kicks-ass.net>
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Alright, we will make a new patch for this. Thanks for the feedback.

Thanks,
Isaac Manjarres
On 2018-07-17 11:34, Peter Zijlstra wrote:
> On Tue, Jul 17, 2018 at 09:30:17AM -0700, Isaac J. Manjarres wrote:
>> After cpu_stop_queue_two_works() queues the cpu_stop works
>> for the stopper threads, it releases the locks held for
>> both threads, which enables preemption, which allows the
>> following race condition to occur:
> 
> 
> Does not apply because an earlier version is already applied.
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/kernel/stop_machine.c?id=9fb8d5dc4b649dd190e1af4ead670753e71bf907
> 
> if there still is a problem, please send a new patch that describes the
> remaining problem.