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Date: Fri, 2 May 2003 11:21:17 +0200
From: Stefan Farfeleder <stefan+current@fafoe.dyndns.org>
To: "Wilkinson,Alex" <Alex.Wilkinson@dsto.defence.gov.au>
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cc: current@freebsd.org
Subject: Re: panic: ffs_blkfree: freeing free frag
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On Fri, May 02, 2003 at 04:43:32PM +0930, Wilkinson,Alex wrote:
> What is a DDB backtrace ? I thought you have already doen the backtrace with:
> 
> (kgdb) bt
> #0  doadump () at /usr/home/stefan/freebsd/src/sys/kern/kern_shutdown.c:238
> #1  0xc022bf33 in boot (howto=260)
>     at /usr/home/stefan/freebsd/src/sys/kern/kern_shutdown.c:370
> #2  0xc022c27b in panic ()
> 
> ....

This backtrace was obtained by running GDB on a kernel crash dump.  DDB
is the in-kernel debugger which allows you to see a backtrace (among
other things) at the time the panic happens, before dumping and
rebooting.

> And why would being in X affect doing a DDB ?

This is a notebook that lacks a serial interface.  DDB can only print to
the console, so it just tries to produce a dump and reboots.

Regards,
Stefan Farfeleder