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    SubjectRe: tickle nmi watchdog whilst doing serial writes.
    On Sun, May 15, 2005 at 02:20:14PM +0200, Andi Kleen wrote:
    > Then someone needs to convince Linus to export touch_nmi_watchdog
    > again.
    >
    > Or how about checking if interrupts are off here (iirc we have
    > a generic function for that now) and then using
    > a smaller timeout and otherwise schedule_timeout() ?

    The interrupt state doesn't tell us whether we can schedule. It
    tells us when we can't schedule, which is different from when we
    can. For example:

    spin_lock(foo_lock);
    ...
    printk("blah blah blah\n");
    ...
    spin_unlock(foo_lock);

    This context is non-preemptable, but doesn't have IRQs disabled.
    The solution would be to keep a "spinlock depth" counter, but
    obviously that's not a possibility.

    I would agree that the most correct thing to do would be to export
    touch_nmi_watchdog()... if only Linus would accept the arguments
    _for_ exporting it.

    --
    Russell King
    Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
    maintainer of: 2.6 Serial core
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