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Date: Mon, 1 Aug 2011 13:11:27 -0700
Message-ID: <CAAuSN92zxF9ZDuMhgrB_sBUrt+O4jGJ=AMe_iNMYSwXo9o79Kw@mail.gmail.com>
Subject: Re: [PATCH v3 2/2] Make hard lockup detection use timestamps
From: ZAK Magnus <zakmagnus@google.com>
To: Don Zickus <dzickus@redhat.com>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@elte.hu>,
        Mandeep Singh Baines <msb@chromium.org>
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On Mon, Aug 1, 2011 at 12:24 PM, Don Zickus <dzickus@redhat.com> wrote:
> One idea I thought of to workaround this is to save the timestamp and the
> watchdog bool and restore after the stack dump.  It's a cheap hack and I
> am not to sure about the locking as it might race with
> touch_nmi_watchdog().  But it gives you an idea what I was thinking.
Yes, I see. Is the hackiness of it okay?

> Being in the nmi context, no one can normally touch these variables,
> except for another cpu using touch_nmi_watchdog() (or watchdog_enable()
> but that should never race in these scenarios).
Well, the soft lockup stuff is not a NMI but just a regular interrupt,
right? Is that also okay?