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Date: Wed, 27 Nov 2013 02:49:12 -0800 (PST)
From: Don Lewis <truckman@FreeBSD.org>
Subject: Re: panic: double fault with 11.0-CURRENT r258504
To: kostikbel@gmail.com
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On 27 Nov, I wrote:
> On 27 Nov, Konstantin Belousov wrote:
>> On Wed, Nov 27, 2013 at 01:13:41AM -0800, Don Lewis wrote:
>>> On 27 Nov, Konstantin Belousov wrote:
>>> > On Wed, Nov 27, 2013 at 12:22:27AM -0800, Don Lewis wrote:
>>> >> It took a while, but I just got another double fault, though this one is
>>> >> somewhat different.  This time it trapped in cpu_switch(), which
>>> >> resulted in calls to
>>> >> trap()->printf()->...->putchar()->msgbuf_addstr()->_mtx_lock_spin_flags()
>>> >> where it trapped again.
>>> >> 
>>> >> Sitting at DDB prompt ...
>>> > 
>>> > Does 'show allpcpu' work ?
>>> 
>>> Yup.  For both CPUs, curthread == idlethread, both CPUs have the same
>>> curpcb.  What is "dynamic pcpu"?  The values differ considerably between
>>> the two CPUs.
>> 
>> Are you sure about curpcb being the same for two CPUs ? This is rather
>> broken.  The best would be to show the actual ddb output.
> 
> It turns out that they are different:
> 	0xe4f62d60
> 	0xe4f65d60
> 
> Screenshot here: <http://people.freebsd.org/~truckman/doublefault1.JPG>

And screenshot of the stack trace here:

<http://people.freebsd.org/~truckman/doublefault2.JPG>