APAR status
Closed as program error.
Error description
Error Message: A crash in gc or null pointer exceptions is observed. . Stack Trace: The exception is not limited to a particular method. So stack trace may vary. A crash in gc usually occurs after the exceptions. An example for the crash is: ----------- Stack Backtrace ----------- (0x00007FE6C350D371 <OSB>libj9gc28.so+0x3b371<CSB>) (0x00007FE6C8F20DFA <OSB>libj9jit28.so+0x971dfa<CSB>) (0x00007FE6C8F213DA <OSB>libj9jit28.so+0x9723da<CSB>) (0x00007FE6C8F2273A <OSB>libj9jit28.so+0x97373a<CSB>) (0x00007FE6CA1EAEF1 <OSB>libj9vm28.so+0xacef1<CSB>) 0000000000BE8000: Object neither in heap nor stack-allocated in thread Pooled Thread <thread ID> . This issue could be observed on X86, Power, or Z. This only happens when a heap larger than 32G is configured and the jvm is running in compressedrefs mode
Local fix
Normally using -Xjit:disableEscapeAnalysis could stop the crash from happening.
Problem summary
In compressedrefs mode, a special memory alignment should be enforced. In this case, when a heap is larger than 32G, JIT didn't align some objects, most likely primitive arrays. JIT compiled method or GC would assume all objects are aligned and try to access the memory, resulting in a NPE or a crash.
Problem conclusion
JIT has been fixed to properly align all objects. . This APAR will be fixed in the following Java Releases: 8 SR3 FP10 (8.0.3.10) . Contact your IBM Product's Service Team for these Service Refreshes and Fix Packs. For those running stand-alone, information about the available Service Refreshes and Fix Packs can be found at: https://www.ibm.com/developerworks/java/jdk/
Temporary fix
Comments
APAR Information
APAR number
IV86745
Reported component name
JIT
Reported component ID
620700124
Reported release
130
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2016-07-08
Closed date
2016-07-08
Last modified date
2016-07-08
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
JIT
Fixed component ID
620700124
Applicable component levels
R130 PSY
UP
[{"Business Unit":{"code":"BU048","label":"IBM Software"},"Product":{"code":"SSC9HBA","label":"Just In Time (JIT) Compiler"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"130","Edition":"","Line of Business":{"code":"","label":""}}]
Document Information
Modified date:
08 July 2016