APAR status
Closed as program error.
Error description
Error Message: The Java application appears to hang while executing a loop (the loop is running for a long time and is always see when sampling the operation of the 'hung' process) - the VM does not respond to signals and the process continues to consume CPU time. . Stack Trace: N/A .
Local fix
The problem can be worked around by specifying -Xjit:disableLoopVersioner for the compiled methods where the hang appears to be occurring. There is a real risk of measurable performance degradation with this option.
Problem summary
In some circumstances the JIT optimizer will create tests ahead of loops to test if they are long running - this determines if the compiled code should periodically check for interruptions. In rare circumstances later optimizations in the JIT can move these tests from being before the loop where they were created to before the start of other enclosing loops. This motion can then cause other optimizations to make incorrect assumptions about the behavior of the program and to incorrectly omit interruption checks.
Problem conclusion
The JIT optimizer has been corrected to ensure that the motion of tests for long running loops does not lead to interruption checks being omitted restoring expected program behavior. . This APAR will be fixed in the following Java Releases: 8 SR3 (8.0.3.0) . 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
IV83132
Reported component name
JIT
Reported component ID
620700124
Reported release
130
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2016-03-29
Closed date
2016-03-29
Last modified date
2016-03-29
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:
29 March 2016