APAR status
Closed as program error.
Error description
Error Message: SIGSEGV in JIT compiled code . Stack Trace: N/A . The problem can occur on any platform as long as you are using the gencon or optavgpause gc policies, the problem is related to "write barriers" which are only used with the parallel mark GC phase. This problem does NOT exist in Java 6.0 (J9VM R24) or earlier.
Local fix
The problem is best avoided by using the following Java command line option to disable on JIT optimization phase: -Xjit:disableLoopVersioner The problem can also be avoid by using the flatheap GC policy. Both options will have some effect on performance but the JIT option is not likely to have a noticeable effect on performance and therefore it is the work-around we would suggest in most cases.
Problem summary
When the JIT compiler is duplicating code (JIT IL nodes) it can forget to reset the NULL and Non-NULL flags, this potentially leads the JIT to conclude that some code can be removed resulting in a store to a NULL pointer and a crash.
Problem conclusion
The JIT was modified so that it correctly clears the NULL/Non-NULL flags when duplicating code (JIT IL nodes) for use with write barriers. . This APAR will be fixed in the following Java Releases: 8 SR3 (8.0.3.0) 7 SR9 FP40 (7.0.9.40) 7 R1 SR3 FP40 (7.1.3.40) 6 R1 SR8 FP25 (6.1.8.25) . 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
IV81731
Reported component name
JIT
Reported component ID
620700124
Reported release
130
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2016-02-22
Closed date
2016-02-24
Last modified date
2016-02-29
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
R260 PSY
UP
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Document Information
Modified date:
29 February 2016