IZ83215: JAVA JIT - LONG COMPILATION TIMES
Closed as program error.
Error Message: Long compilation times (1-5min observed) resulting in long GC delays in Java5 (The problem exists in Java6, but it does not cause GC delays). When the delay is seen the stack trace would contain several recursive calls to the following JIT compiler function: lookForModifiedParameters__28TR_ParameterToArgumentMapperFP7TR_N ode() . Stack Trace: lookForModifiedParameters__28TR_ParameterToArgumentMapperFP7TR_N ode() at 0xd207ad94 ... lookForModifiedParameters__28TR_ParameterToArgumentMapperFP7TR_N ode() at 0xd207ad98 lookForModifiedParameters__28TR_ParameterToArgumentMapperFv() at 0xd207ad18 initialize__28TR_ParameterToArgumentMapperFv() at 0xd2078a44 inlineCallSite__14TR_InlinerBaseFP23TR_ResolvedMethodSymbolP12TR _CallStackP10TR_TreeTopP7TR_NodeT4P24TR_VirtualGuardSelectionP19 TR_OpaqueClassBlocki() at 0xd2077e58 inlineCallSite__14TR_InlinerBaseFP23TR_ResolvedMethodSymbolP12TR _CallStackP10TR_TreeTopP7TR_NodeT4P24TR_VirtualGuardSelectionP19 TR_OpaqueClassBlockP14TR_PrexArgInfo() at 0xd2075350 inlineCallSites__19TR_CallGraphInlinerFP23TR_ResolvedMethodSymbo lP12TR_CallStackP24TR_InnerPreexistenceInfo() at 0xd2076090 performInlining__14TR_InlinerBaseFP23TR_ResolvedMethodSymbol() at 0xd2071350 perform__10TR_InlinerFv() at 0xd20711f4 IPRA.$performOptimization__16TR_OptimizerImplFPQ2_16TR_Optimizer Impl12OptimizationiN22() at 0xd1fdc2f8 optimize__16TR_OptimizerImplFv() at 0xd1fdaf84 performOptimizations__14TR_CompilationFv() at 0xd1f91acc compile__14TR_CompilationFv() at 0xd1f916b8 . In general this problem will not last long enough to be mistaken for a hang (i.e. this problem should not cause delays that lasts for hours, only minutes). The problem can occur in Java5 and Java6 but the symptoms are more likely to remain hidden in Java6. All IBM J9 platforms are effected including 32 and 64bit JVMs.
The problem can be avoid by disabling the JIT optimization called inlining, but doing so will have a noticeable impact on the performance of JIT compiled code. -Xjit:disableInlining This option can be applied to a single method which will have very little impact on performance, but you will need to determine what method is causing the problem to occur in order limit the option to only one method.
The JIT compiler is recursively calling a function due to a string of Java methods where the parameter to one method call is the return value from the previous call.
This defect will be fixed in: 5.0.0 SR13 6.0.0 SR9 . The JIT was modified to eliminate unnecessary recursion. . To obtain the fix: Install build 20100924 or later
Reported component name
JAVA 5 JIT
Reported component ID
Last modified date
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fixed component name
JAVA 5 JIT
Fixed component ID
Applicable component levels