misc/177876: kernel stack overflow panic on mips64, EdgeRouter Lite

[Joe Holden]

>Number:         177876
>Category:       misc
>Synopsis:       kernel stack overflow panic on mips64, EdgeRouter Lite
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Apr 15 21:50:00 UTC 2013
>Closed-Date:
>Last-Modified:
>Originator:     Joe Holden
>Release:        FreeBSD 10.0-CURRENT #4 r249363
>Organization:
Pseudo Networks Limited
>Environment:
FreeBSD erl1 10.0-CURRENT FreeBSD 10.0-CURRENT #4 r249363: Mon Apr 15 07:55:44 BST 2013     root at abby.lhr1.as41113.net:/usr/obj/mips.mips64/usr/src/sys/OCTEON-ERL  mips
>Description:
Under heavy CPU load, after a an hour or so FreeBSD will panic and reboot with the following:

panic: kernel stack overflow - trapframe at 0xffffffff80835eb0
cpuid = 0

The panic is identical all the time and only happens under heavy CPU load which of course may well happen in the field.

Ideally I'd like someone to advise me on how to debug the problem, failing that it should be easy enough to recreate.

It may well be a hardware issue as these boxes do run very hot, bordering on thermal design limits.
>How-To-Repeat:
Start compiling a port.
>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: