APAR status
Closed as program error.
Error description
Error Message: Crash during GC or assert in GC . Stack Trace: 0x006f472a {libj9prt26.so}{j9dump_create} <OSB>0x9697b0e8<CSB> 0x00818e3e {libj9dmp26.so}{doSystemDump} <OSB>0x9697b228<CSB> 0x00817617 {libj9dmp26.so}{protectedDumpFunction} <OSB>0x9697b248<CSB> 0x00703fd2 {libj9prt26.so}{j9sig_protect} <OSB>0x9697b348<CSB> 0x008175e8 {libj9dmp26.so}{runDumpFunction} <OSB>0x9697b388<CSB> 0x0081c545 {libj9dmp26.so}{runDumpAgent} <OSB>0x9697b7f8<CSB> 0x0082f457 {libj9dmp26.so}{triggerDumpAgents} <OSB>0x9697bad8<CSB> 0x001474cc {libj9trc26.so}{twAssertion} <OSB>0x9697baf8<CSB> 0x002e0d83 {libj9ute26.so}{utsTraceV} <OSB>0x9697bba8<CSB> 0x00148974 {libj9trc26.so}{j9Trace} <OSB>0x9697bbe8<CSB> 0x0655e540 {libj9gc26.so}{_ZN31MM_ParallelScavengerRootScanner11doStackSlot EPP8J9ObjectPvPKv} <OSB>0x9697bc68<CSB> 0x0651b911 {libj9gc26.so}{_Z17stackSlotIteratorP8J9JavaVMPP8J9ObjectPvP16J9 StackWalkStatePKv} <OSB>0x9697bc88<CSB> 0x0665b7b7 {libj9gc26.so}{vmThreadStackDoOSlotIterator} <OSB>0x9697bca8<CSB> 0x01504cbc {libj9jit26.so}{walkJITFrameSlots} <OSB>0x9697bcf8<CSB> 0x0150507c {libj9jit26.so}{jitWalkFrame} <OSB>0x9697bd88<CSB> 0x015059ee {libj9jit26.so}{jitWalkStackFrames} <OSB>0x9697bdf8<CSB> 0x001eb022 {libj9vm26.so}{.L118} <OSB>0x9697bee8<CSB> 0x0665b83f {libj9gc26.so}{_ZN28GC_VMThreadStackSlotIterator9scanSlotsEP10J9 VMThreadS1_PvPFvP8J9JavaVMPP8J9ObjectS2_P16J9StackWalkStatePKvEb b} <OSB>0x9697bff8<CSB> 0x0651cea5 {libj9gc26.so}{_ZN14MM_RootScanner13scanOneThreadEP20MM_Environm entModronP10J9VMThreadPv} <OSB>0x9697c068<CSB> 0x0651bf11 {libj9gc26.so}{_ZN14MM_RootScanner11scanThreadsEP20MM_Environmen tModron} <OSB>0x9697c0b8<CSB> 0x0651cd30 {libj9gc26.so}{_ZN14MM_RootScanner9scanRootsEP20MM_EnvironmentMo dron} <OSB>0x9697c0d8<CSB> 0x0654fa80 {libj9gc26.so}{_ZN20MM_ParallelScavenger13scavengeRootsEP22MM_En vironmentStandard} <OSB>0x9697c128<CSB> 0x065585ac {libj9gc26.so}{_ZN20MM_ParallelScavenger24workThreadGarbageColle ctEP22MM_EnvironmentStandard} <OSB>0x9697c198<CSB> 0x06591d15 {libj9gc26.so}{_ZN23MM_ParallelScavengeTask3runEP20MM_Environmen tModron} <OSB>0x9697c1b8<CSB> 0x06675aa0 {libj9gc26.so}{_ZN21MM_ParallelDispatcher15slaveEntryPointEP20MM _EnvironmentModron} <OSB>0x9697c1d8<CSB> 0x06675c68 {libj9gc26.so}{_Z23dispatcher_thread_proc2P13J9PortLibraryPv} <OSB>0x9697c218<CSB> 0x00703fd2 {libj9prt26.so}{j9sig_protect} <OSB>0x9697c318<CSB> 0x066751ed {libj9gc26.so}{dispatcher_thread_proc} <OSB>0x9697c358<CSB> 0x00d261e5 {libj9thr26.so}{thread_wrapper} <OSB>0x9697d388<CSB> 0x00596a49 {libpthread.so.0}{start_thread} <OSB>0x9697d498<CSB> NOTE: This APAR is not the only problem that could cause this stack trace. Finding a crash with the above stack trace does not guarantee the applicability of this APAR. . The problem can only occur in Java on x86 (Linux or Windows). It can only occur when an agent is installed that puts the JVM in debug mode (JIT FSD mode).
Local fix
The problem can be avoided by removing the debugging agent so that the JVM will run in normal mode.
Problem summary
The JIT would fail to mark a stack slot as "non-collectable" before the slot is re-used as a parameter to an OS call as part of executing a currentTimeMillis() Java call. This would cause the GC to process the stack slot on a GC cycle resulting in a crash or an assert as the GC would expect to find an object reference in that slot.
Problem conclusion
This defect will be fixed in: 6.0.1 SR7 7.0.0 SR6 6.0.0 SR15 5.0.0 SR16 FP4 . One of the JIT optimizations is now disabled when in debugging mode (FSD mode) so that the JIT will not lose the ability to precisely know the "liveness" of stack slots.
Temporary fix
Comments
APAR Information
APAR number
IV47986
Reported component name
JIT
Reported component ID
620700124
Reported release
260
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2013-09-06
Closed date
2013-09-06
Last modified date
2013-09-13
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
IV47987
Fix information
Fixed component name
JIT
Fixed component ID
620700124
Applicable component levels
R260 PSY
UP
R600 PSY
UP
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Document Information
Modified date:
13 September 2013