[Pkg-sysvinit-devel] Bug#672959: kfreebsd-*: panic: vm_fault_copy_wired

[Axel Beckert]

Hi,

here are my observations so far after several hours and evenings of
rebooting my kFreeBSD EeeBox again and again.

I've unfortunately not yet found the real cause or an solution, but
maybe some of my observations spark ideas at others. I'll continue
debugging the issue on Monday evening as I'm not at home for the
weekend.

Roger Leigh wrote:
> Looking at the screenshot you attached, I can't see any obvious
> reason for fsck to make the kernel panic.  There's no indication
> of odd scripts (other than geli) running in parallel here.

Same here. But compared to
http://bugs.debian.org/cgi-bin/bugreport.cgi?msg=30;filename=vm_fault_copy_wired.png;att=1;bug=672959
and
http://bugs.debian.org/cgi-bin/bugreport.cgi?msg=35;filename=kfreebsdcrash.png;att=1;bug=672959
where crash happens after 4 and 6 seconds, my fsck runs around 7
_minutes_ before it crashes. So I doubt that after 7 minutes
uptime a job running parallel _to_ checkroot causes this.

One of the screenshots also hints that the crash is after checkroot.sh
and my experience confirms that, also because my fsck always runs more
than 6 minutes and I think that this means it's likely caused by
something which comes after the checkroot.sh.

Interestingly pressing Ctrl-C during the fsck gives you (after
entering the root password) a working shell and starting
"/etc/init.d/checkroot.sh start" manually there works without issues.
Exiting the shell reboots (cleanly) and then the system comes up
cleanly again. (Should work as workaround without any preparations
like creating shell scripts to run be instead of init or a live CD to
run the fsck manually. Just be quick enough if your fsck just takes a
few seconds. :-)

So I added "set -x" to all init.d scripts and (unfortunately) the
crash seems to always happen after the last line of checkroot.sh which
is ":", i.e. the last line shown always was "+ :" and the second last
line was "+ rm -f /dev/rootdev".

So I commented out the removal of /dev/rootdev, but that didn't change
anything either.

I also played around with additional dependencies based on guessing
(e.g. added dependencies on devd or urandom) to at least all the
scripts which have checkroot as direct dependencies to reduce the
parallelism after checkroot.sh, but that didn't change anything
either so far.

		Regards, Axel
-- 
 ,''`.  |  Axel Beckert <abe at debian.org>, http://people.debian.org/~abe/
: :' :  |  Debian Developer, ftp.ch.debian.org Admin
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