Test nsk/regression/b6186200 crashed with 6u4p-b02 during promotion testing on solaris-sparcv9 bits.
Results are available here
http://sqeweb.sfbay/nfs/tools/gtee/results/JDK_PERFORMANCE/PROMOTION/VM/6u4p/b02/CMS/2007-12-14/vm/64BITSOLSPARC5.10/server/mixed/vm-64BITSOLSPARC5.10_server_mixed_nsk.regression.testlist2007-12-14-12-52-21/analysis.html
or here
/net/sqenfs-1.sfbay/export1/tools/gtee/results/JDK_PERFORMANCE/PROMOTION/VM/6u4p/b02/CMS/2007-12-14/vm/64BITSOLSPARC5.10/server/mixed/vm-64BITSOLSPARC5.10_server_mixed_nsk.regression.testlist2007-12-14-12-52-21

This failure reproduce permanently with all current trains 6u4p/6u4/7.

Hss_err file:
#
# An unexpected error has been detected by Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0xffffffff7dfac208, pid=28359, tid=3
#
# Java VM: Java HotSpot(TM) 64-Bit Server VM (11.0-b09 mixed mode solaris-sparc)
# Problematic frame:
# V [libjvm.so+0x3ac208]
#
# If you would like to submit a bug report, please visit:
# http://java.sun.com/webapps/bugreport/crash.jsp
#

--------------- T H R E A D ---------------

Current thread (0x0000000100132400): ConcurrentGCThread [stack: 0xffffffff6c600000,0xffffffff6c700000] [id=3]

siginfo:si_signo=SIGSEGV: si_errno=0, si_code=1 (SEGV_MAPERR), si_addr=0x0000000000000018

Registers:
 O0=0x0000000000042000 O1=0xffffffff72218868 O2=0x0000000000000000 O3=0x0000000000000000
 O4=0x0000000000000000 O5=0x0000000000000001 O6=0xffffffff6c6fead1 O7=0xffffffff7dfac0d0
 G1=0x0000000000042d50 G2=0x0000000000000000 G3=0xffffffff7e5f5630 G4=0x0000000000000001
 G5=0xffffffff7e5ae000 G6=0x0000000000000000 G7=0xffffffff6c500000 Y=0x0000000000000000
 PC=0xffffffff7dfac208 nPC=0xffffffff7dfac20c


Top of Stack: (sp=0xffffffff6c6ff2d0)
0xffffffff6c6ff2d0: 0000000000000001 ffffffff6d100000
0xffffffff6c6ff2e0: 00000000000ecc00 000000000001d980
0xffffffff6c6ff2f0: 0000000000766000 0000000000766000
0xffffffff6c6ff300: 0000000003b30000 0000000100131c00
0xffffffff6c6ff310: ffffffff6c6ff570 ffffffff723f0000
0xffffffff6c6ff320: ffffffff6c6ff570 0000000000000000
0xffffffff6c6ff330: 0000000000000000 ffffffff7e5f0d50
0xffffffff6c6ff340: ffffffff6c6feb81 ffffffff7df8245c
0xffffffff6c6ff350: 0000000000000000 0000000000298000
0xffffffff6c6ff360: ffffffff73cc0000 0000000000000000
0xffffffff6c6ff370: 0000000100131d40 0000000100131e60
0xffffffff6c6ff380: ffffffff7e5d9b78 ffffffff7df2ce70
0xffffffff6c6ff390: ffffffff7e5daf38 ffffffff6c6ff418
0xffffffff6c6ff3a0: 0000000000000000 ffffffff7e5ae000
0xffffffff6c6ff3b0: ffffffff723f0000 00000000001d7798
0xffffffff6c6ff3c0: 000000010011c170 ffffffff6c6ff570

Instructions: (pc=0xffffffff7dfac208)
0xffffffff7dfac1f8: 00 00 00 00 00 00 00 00 9d e3 bf 50 c4 5e 60 08
0xffffffff7dfac208: c2 00 a0 18 80 a0 60 00 14 40 00 1a 91 38 60 03

Stack: [0xffffffff6c600000,0xffffffff6c700000], sp=0xffffffff6c6ff2d0, free space=1020k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0x3ac208]
V [libjvm.so+0x382464]
V [libjvm.so+0x3a7058]
V [libjvm.so+0x3a66ac]
V [libjvm.so+0x39c2e4]
V [libjvm.so+0x3b0588]
V [libjvm.so+0x638cdc]
...