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Date: Mon, 1 Aug 2011 11:33:24 -0700
Message-ID: <CAAuSN92UAjuJXprBAj9z0sekk=iBWGe3PP88z8NmrZ5fExOyjg@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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Okay... So this is a problem we need to solve. Does there exist a good
way to output a stack trace to, say, a file in /proc? I think that
would be an appealing solution, if doable.

On Mon, Aug 1, 2011 at 5:52 AM, Don Zickus <dzickus@redhat.com> wrote:
> On Fri, Jul 29, 2011 at 04:12:32PM -0700, ZAK Magnus wrote:
>> Are you saying that any call to printk() will touch the watchdogs? I
>> wasn't aware of that and it doesn't seem to comply with my
>> observations too well, either. Then again, at the moment I don't
>> understand some of the things I'm currently seeing so I could just be
>> wrong.
>
> I believe the serial console write is the source of all the
> touch_nmi_watchdogs that result from a printk.
>
> drivers/tty/serial/8250.c::serial8250_console_write()
>
> Cheers,
> Don
>