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Date: Thu, 22 Mar 2012 11:32:26 +0100 (CET)
From: Thomas Gleixner <tglx@linutronix.de>
To: Alexander Gordeev <agordeev@redhat.com>
cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/3] genirq: Get rid of unneeded force parameter in
 irq_finalize_oneshot()
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On Mon, 19 Mar 2012, Alexander Gordeev wrote:

> The only place irq_finalize_oneshot() is called with force parameter set
> is the threaded handler error exit path. But IRQTF_RUNTHREAD is dropped
> at this point and irq_wake_thread() is not going to reset it again,
> since PF_EXITING is set for this thread already. So we will drop the
> thread's bit in threads_oneshot anyway and the force parameter is
> superfluous.

Wrong.

CPU 0				CPU 1

    do_exit()
				check(PF_EXITING)
				set_bit(IRQTF_RUNTHREAD)
				...
    set(PF_EXITING)
    exit_irq_thread()

    if (test_bit(IRQTF_RUNTHREAD))
	goto out;

	-> FAIL

Thanks,

	tglx