Re: 8.0RC2 amd64 - kernel panic running make buildworld

On Sat, 2009-10-31 at 23:15 +0100, Kai Gallasch wrote:
> Hi.
> 
> I installed 8.0RC2-amd64 on an 8-core opteron server a few days ago.
> 
> When I try to do a make buildworld or make buildkernel the server
> reboots without any message left in the logs. The same happens
> when building bigger ports (for example ruby18 or perl58)
> 
> With 8.0-RC2 debug flags and witness seem to be disabled in the
> standard GENERIC kernel, so unfortunately it is not possible for me to
> build a debug kernel without my server crashing..

First place I think I'd start id by running memtest86 on the machine
overnight.  This sounds like possible hardware issue to me, it would be
good to see if we can confirm that that is the case.

> Now my idea was to install the old 8.0-BETA4 and upgrade to RC2 through
> makeworld + buildkernel (gdb+witness). But no luck. When trying to
> upgrade to RC2 the 8.0-BETA4 also crashes. At least 8.0-BETA4 has debug
> + witness active in the GENERIC kernel..
> 
> So below some debug output of 8.0-BETA4 crashing. Has a vfs/ffs LOR
> problem with the BETA4 already been fixed?

The debug output you included were just lock order reversals, and don't
seem to be related to your crash.

I think 8.0-BETA4 still had the debugger compiled in (you can test by
pressing ctrl-alt-escape ion the console, if you do drop to the
debugger, give the "c" command to continue).

If the debugger is compiled in, then the spontaneous reboot without
dropping to the debugger suggests even more that it may be hardware
related.  If you do get to the debugger, a copy of all of the messages
on screen and the output of the "bt" command would be very useful.  When
you do your kernel recompile, please include full debugging, including
WITNESS, INVARIANTS, KDB, DDB etc.

FWIW, don't worry about building world now, a BETA4 world should work
fine with a RC2 kernel.  You may be able to get a kernel built even
though it keeps crashing by clearing out /usr/obj to start with and then
just repeating
cd /usr/src && make buildkernel -DKERNFAST
after every crash.

> Does it make sense to send in a pr with the old 8.0-BETA4? 

It depends what the bug is to be honest.  So far there isn't really
enough information to determine the cause, and therefore there isn't
really enough info for a PR.

Gavin