jtreg M&M tests failed intermittently on Solaris-sparc and Solaris x86 last two days and they ran with -XX:+UseConcMarkSweepGC.

java/lang/management/MemoryMXBean/MemoryManagementConcMarkSweepGC.sh
failed on solaris x86 (note: b54 server VM) with the following assertion:

# Internal Error (/export0/BUILD_AREA/jdk6.0/hotspot/src/share/vm/memory/concurrentMarkSweepGeneration.cpp, 6433), pid=14639, tid=6
#
# Java VM: Java HotSpot(TM) Server VM (1.6.0-ea-fastdebug-b54-debug mixed mode)
#
# Error: assert(_finger > ptr,"we just incremented it above")
# An error report file with more information is saved as hs_err_pid14639.log
#
# If you would like to submit a bug report, please visit:
# http://java.sun.com/webapps/bugreport/crash.jsp
#

I can reproduce the crash once out of 7-10 runs. I got a different assertion:
  assert(s > 0,"Bad size calculated")
when I ran with the current service_hs_baseline VM.

java/lang/management/MemoryMXBean/LowMemoryTestConcMarkSweepGC.sh
failed on solaris sparc (note: b55 server VM) with the following assertion:

# Internal Error (/BUILD_AREA/jdk6.0/hotspot/src/share/vm/oops/oop.inline.hpp, 183 [ Patched ]), pid=9265, tid=6
#
# Java VM: Java HotSpot(TM) Server VM (1.6.0-ea-fastdebug-b55-debug mixed mode)
#
# Error: assert(s > 0,"Bad size calculated")
# An error report file with more information is saved as hs_err_pid9265.log
#
# If you would like to submit a bug report, please visit:
# http://java.sun.com/webapps/bugreport/crash.jsp
#