Re: [RESEND][PATCH v3] watchdog: Fix disable/enable regression

From: Don Zickus
Date: Thu Dec 20 2012 - 14:18:08 EST


On Wed, Dec 19, 2012 at 10:44:44PM +0100, Bjørn Mork wrote:
> Bjørn Mork <bjorn@xxxxxxx> writes:
> > Don Zickus <dzickus@xxxxxxxxxx> writes:
> >
> >> What about the opposite cases?
> >> nmi_watchdog=1
> >> echo 1 > /sys/devices/system/cpu/cpu1/online
> >
> > I don't see why not. But verifying it would be nice. I thought that it
> > would be a simple thing to test using qemu-kvm, but it seems that the
> > CPU hotplugging support there isn't quite ready. The guest just dies
> > with "Assertion `bus->allow_hotplug' failed."
> >
> > I'll go digging for alternatives, but if anyone else could verify this
> > then I'd appreciate it.
>
> I just realized that you might not really want/need hotplugging, but
> just booting with some cores initially offline?

Actually, I did a poor job explaining myself but your previous email
answered my question.

The original problem was that hrtimer_cancel was being called on an
un-initialized object. I was wondering what happens if watchdog_enable
was called multiple times, would it re-initialize a new object causing a
memory leak?

But as you pointed out that couldn't happen.

So I am fine with your changes. Thanks for the initial and follow up
testing.

Acked-by: Don Zickus <dzickus@xxxxxxxxxx>
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