During testing we've hit

#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error
(/home/jc234399/ws/6819077c/hotspot/src/share/vm/gc_implementation/g1/heapRegionRemSet.cpp:599),
pid=241, tid=8
# Error: assert(contains_reference(from),"We just added it!")
#
# JRE version: 7.0-b58
# Java VM: OpenJDK Server VM (16.0-b02-internal-jvmg mixed mode
solaris-x86 )
# If you would like to submit a bug report, please visit:
# http://java.sun.com/webapps/bugreport/crash.jsp
#

a couple of times.

John Cuthbertson hit it with the following

"The test case was again SPECjbb2005, 32 bit JVM, 2Gb of heap, 1s/4c x86 Sun 24 running solaris 10. According to the back trace we're updating a Rset for a heap region. I've seen this twice so far out of around 50 runs (overnight). "
I also hit it by running specjbb2000 inside the GC test suite. The build was fastedbug / server / amd64 running on Solaris.