APAR status
Closed as program error.
Error description
Error Message: Unhandled exception Type=Segmentation error vmState=0x00020002 J9Generic_Signal_Number=00000004 Signal_Number=0000000b Error_Value=00000000 Signal_Code=00000001 Handler1=F6D38D09 Handler2=F6CF9257 InaccessibleAddress=0000000C EDI=00000001 ESI=00000000 EAX=080708F0 EBX=F62FA200 ECX=D9E90390 EDX=08070880 EIP=F61FDF9E ES=002B DS=002B ESP=938D8FA0 EFlags=00010246 CS=0023 SS=002B EBP=938D90A8 Module=/jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270s r3-20121025_01/ibm-java-i386-70/jre/lib/i386/default/libj9gc26.s o Module_base_address=F614D000 Target=2_60_20121024_126071 (Linux 3.0.38-0.5-default) CPU=x86 (4 logical CPUs) (0xf7926000 RAM) . Stack Trace: p> 20121102-14:39:22 <gdb> #0 0xf6c5e8fa in j9dump_create () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3-2012 1025_01/ibm-java- i386-70/jre/lib/i386/default/libj9prt26.so p> 20121102-14:39:22 <gdb> #1 0xf699ae4e in doSystemDump () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3-2012 1025_01/ibm-java- i386-70/jre/lib/i386/default/libj9dmp26.so p> 20121102-14:39:22 <gdb> #2 0xf6999627 in protectedDumpFunction () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3- 20121025_01/ibm-java-i386-70/jre/lib/i386/default/libj9dmp26.so p> 20121102-14:39:22 <gdb> #3 0xf6c6e202 in j9sig_protect () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3-2012 1025_01/ibm-java- i386-70/jre/lib/i386/default/libj9prt26.so p> 20121102-14:39:22 <gdb> #4 0xf69995f8 in runDumpFunction () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3-2012 1025_01/ibm- java-i386-70/jre/lib/i386/default/libj9dmp26.so p> 20121102-14:39:22 <gdb> #5 0xf699e555 in runDumpAgent () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3-2012 1025_01/ibm-java- i386-70/jre/lib/i386/default/libj9dmp26.so p> 20121102-14:39:22 <gdb> #6 0xf69b1947 in triggerDumpAgents () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3-2012 1025_01/ibm- java-i386-70/jre/lib/i386/default/libj9dmp26.so p> 20121102-14:39:22 <gdb> #7 0xf6cac197 in generateDiagnosticFiles () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3- 20121025_01/ibm-java-i386-70/jre/lib/i386/default/libj9vm26.so p> 20121102-14:39:22 <gdb> #8 0xf6c6e202 in j9sig_protect () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3-2012 1025_01/ibm-java- i386-70/jre/lib/i386/default/libj9prt26.so p> 20121102-14:39:22 <gdb> #9 0xf6cac3ae in vmSignalHandler () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3-2012 1025_01/ibm- java-i386-70/jre/lib/i386/default/libj9vm26.so p> 20121102-14:39:22 <gdb> #10 0xf6caccc8 in structuredSignalHandler () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3- 20121025_01/ibm-java-i386-70/jre/lib/i386/default/libj9vm26.so p> 20121102-14:39:22 <gdb> #11 0xf6cacd3b in structuredSignalHandlerForJavaVM () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3- 20121025_01/ibm-java-i386-70/jre/lib/i386/default/libj9vm26.so p> 20121102-14:39:22 <gdb> #12 0xf6c6d425 in masterSynchSignalHandler () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3- 20121025_01/ibm-java-i386-70/jre/lib/i386/default/libj9prt26.so p> 20121102-14:39:22 <gdb> #13 <signal handler called> p> 20121102-14:39:22 <gdb> #14 0xf6171f9e in MM_RealtimeMarkingScheme::incrementalConsumeQueue(MM_Environment Realtime*, unsigned int) () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3-2012 1025_01/ibm-java-i386-70/jre/lib/i386/default/libj9gc26.so p> 20121102-14:39:22 <gdb> #15 0xf615e9ed in MM_StaccatoGC::doTracing(MM_EnvironmentRealtime*) () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3-2012 1025_01/ibm-java-i386-70/jre/lib/i386/default/libj9gc26.so p> 20121102-14:39:22 <gdb> #16 0xf61753ad in MM_RealtimeMarkingScheme::markLiveObjects(MM_EnvironmentRealtime *) () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3-2012 1025_01/ibm-java-i386-70/jre/lib/i386/default/libj9gc26.so p> 20121102-14:39:22 <gdb> #17 0xf6171b9d in MM_RealtimeMarkTask::run(MM_EnvironmentModron*) () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3-2012 1025_01/ibm-java-i386-70/jre/lib/i386/default/libj9gc26.so p> 20121102-14:39:22 <gdb> #18 0xf622749e in MM_Dispatcher::run(MM_EnvironmentModron*, MM_Task*) () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3-2012 1025_01/ibm-java-i386-70/jre/lib/i386/default/libj9gc26.so p> 20121102-14:39:22 <gdb> #19 0xf61711b9 in MM_RealtimeGC::incrementalCollect(MM_EnvironmentRealtime*) () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3-2012 1025_01/ibm-java-i386-70/jre/lib/i386/default/libj9gc26.so p> 20121102-14:39:22 <gdb> #20 0xf617154b in MM_RealtimeGC::internalGarbageCollect(MM_EnvironmentModron*, MM_MemorySubSpace*, MM_AllocateDescription*) () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3-2012 1025_01/ibm-java-i386- 70/jre/lib/i386/default/libj9gc26.so p> 20121102-14:39:22 <gdb> #21 0xf60e6705 in MM_Collector::garbageCollect(MM_EnvironmentModron*, MM_MemorySubSpace*, MM_AllocateDescription*, unsigned int, MM_ObjectAllocationInterface*, MM_MemorySubSpace*, MM_AllocationContext*) () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3-2012 1025_01/ibm-java-i386-70/jre/lib/i386/default/libj9gc26.so p> 20121102-14:39:22 <gdb> #22 0xf616a896 in MM_MemorySubSpaceMetronome::collect(MM_EnvironmentModron*, MM_GCCode) () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3-2012 1025_01/ibm-java-i386-70/jre/lib/i386/default/libj9gc26.so p> 20121102-14:39:22 <gdb> #23 0xf617c365 in MM_Scheduler::masterEntryPoint(MM_EnvironmentModron*) () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3-2012 1025_01/ibm-java-i386-70/jre/lib/i386/default/libj9gc26.so p> 20121102-14:39:22 <gdb> #24 0xf623ea94 in dispatcher_thread_proc2(J9PortLibrary*, void*) () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3-2012 1025_01/ibm-java-i386-70/jre/lib/i386/default/libj9gc26.so p> 20121102-14:39:22 <gdb> #25 0xf6c6e202 in j9sig_protect () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3-2012 1025_01/ibm-java- i386-70/jre/lib/i386/default/libj9prt26.so p> 20121102-14:39:22 <gdb> #26 0xf623e075 in dispatcher_thread_proc () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3- 20121025_01/ibm-java-i386-70/jre/lib/i386/default/libj9gc26.so p> 20121102-14:39:22 <gdb> #27 0xf77301e5 in thread_wrapper () from /jtctest/sdk_installs_hc/ESPRESSO/PKG/pxi3270sr3/pxi3270sr3-2012 1025_01/ibm- java-i386-70/jre/lib/i386/default/libj9thr26.so p> 20121102-14:39:22 <gdb> #28 0xf770a809 in start_thread () from /lib/libpthread.so.0 p> 20121102-14:39:22 <gdb> #29 0xf764f1be in clone () from /lib/libc.so.6 . This problem has been discovered by attaching a new version of Health Center to VM and requesting loaded classes stats
Local fix
This issue might intermittently occur because of using GetLoadedClasses() JNI call for VM running with -Xgcpolicy:metronome (Soft Real Time) so it can be worked out by using any other GC policy. If SRT is must to be used try to avoid any functionality might call GetLoadedClasses() (run with attached JVMTI agent for example)
Problem summary
In SRT (only) if JNI GetLoadedClasses() is called at the middle of GC Cycle it might return classes which are technically alive at the moment but about to die (to be unloaded) at the end of this GC Cycle. Such classes might be added to the JNI Tables (JNI Local References for instance) and be a reason for crash in GC after classes unloading.
Problem conclusion
This defect will be fixed in: 6.0.1 SR5 7.0.0 SR4 . The solution is to prevent classes listed in GetLoadedClasses() output to be unloaded.
Temporary fix
Comments
APAR Information
APAR number
IV34348
Reported component name
J9 COMMON CODE
Reported component ID
620700127
Reported release
260
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2013-01-08
Closed date
2013-01-08
Last modified date
2013-01-08
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
J9 COMMON CODE
Fixed component ID
620700127
Applicable component levels
R260 PSY
UP
[{"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSNVBF","label":"Runtimes for Java Technology"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"6.1","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]
Document Information
Modified date:
21 February 2022