2.6.13-rt13 SMP crashes on boot

[John Rigg <lk@sound-man.co.uk>]

I've been trying to get 2.6.13 with RT-preempt patch to run on my
dual Opteron with debugging code (with CONFIG_PREEMPT_RT=y).
It crashes on boot if I enable latency tracing in .config. This happens 
with -rt13, -rt12, and -rt4 versions of the patch. Unfortunately it
occurs before any logging, so I can't provide any log data.
The crash appears to happen just after drive hda is
detected, while it's trying to mount my ext3 / filesystem (on hda7).
The mount fails then the screen fills with a segfault message in an
infinite loop:

segfault at ffffffff8010f20c rip ffffffff8010f20c rsp 00007fffffacdc88

A hard reboot is then required.

Without latency tracing it boots and runs fine with the following:

Kernel debug
	MagicSysRq
Detect soft lockups
Wakeup latency timing
Compile with debug info
Collect scheduler stats
Debug preemptible kernel

With latency tracing the crash occurs even if I disable all other
kernel hacking except for
Magic SysRq, Wakeup latency timing, and Compile w. debug info.

Hardware is 2 x Opteron 240, MSI K8T Master2-FAR (VIA K8T 800) m/board,
1GB ECC RAM. System is Debian amd64 unstable (gcc-4.0_4.0.1-7,
binutils_2.16.1cvs20050902-1).
Copy of .config and lspci output are here:
http://www.sound-man.co.uk/crash

Regards,
John