APAR status
Closed as program error.
Error description
Error Message: A 0C9/FPE (integer Divide by zero) OS signal is thrown causing the JVM to abort. . Stack Trace: {libj9jit29.so}{CpuSelfThreadUtilization::computeThreadCpuUtilOv erLastNns(long)} {libj9jit29.so}{DoCalculateOverallCompCPUUtilization(...)} {libj9jit29.so}{samplerThreadProc(void*)} {libj9thr29.so}{thread_wrapper} . The problem can occur on X86 and IBM-Z machines (but not on POWER because an integer divide by zero does not cause a signal on POWER). On X86 it would be a SIGFPE and on IBM-Z (zOS) it would be a 0C9.
Local fix
The issue is typically made possible by enabling JIT verbose options "compilationThreads" or "compilationThreadsDetails" or by requesting trace point "j9jit.42". The issue could be avoided by making sure those are not enabled. i.e. Remove the java command line argument "-Xjit:verbose={compilationThreads}" or "-Xjit:verbose={compilationThreadsDetails}
Problem summary
The JIT can update it's CPU utilization data structure in more then one thread which results in a race condition which could lead to a divide by zero in computeThreadCpuUtilOverLastNns().
Problem conclusion
The JIT was modified so that it checks for a 0 divisor in the computeThreadCpuUtilOverLastNns() method and returns an error (-1) to the caller in such cases. . This APAR will be fixed in the following Releases: . IBM SDK, Java Technology Edition 8 SR8 FP11 (8.0.8.11) . Contact your IBM Product's Service Team for these Service Refreshes and Fix Packs. For those running stand-alone, information about the available maintenance can be found at: https://www.ibm.com/support/pages/java-sdk
Temporary fix
Comments
APAR Information
APAR number
IJ47675
Reported component name
JIT
Reported component ID
620700124
Reported release
130
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2023-07-22
Closed date
2023-07-24
Last modified date
2023-07-24
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
[{"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":"130","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]
Document Information
Modified date:
25 July 2023