-XX:[+|-]HitachiVerboseGCPrintCause (Option to output the cause of garbage collection)

Format

-XX:+HitachiVerboseGCPrintCause
This option outputs the cause of garbage collection to the end of extended verbosegc information.
-XX:-HitachiVerboseGCPrintCause
This option outputs the extended verbosegc information in the normal format.

Description

Specify whether to output the cause of the garbage collection.

Default value
  • -XX:+HitachiVerboseGCPrintCause
Prerequisite options
  • -XX:+HitachiVerboseGC

When the -XX:+HitachiCommaVerboseGC option is specified, the following cause numbers are output:

Table 16-6 List of causes of garbage collection

Cause numberCauseDescription
0ObjAllocFailThe garbage collection occurred due to the failure in object allocation.
1System.gcThe garbage collection occurred due to the invocation of the java.lang.System.gc method.
2PermAllocFailThe garbage collection occurred due to the failure in allocation of the permanent heap.
3DelayedGCThe reserved garbage collection is invoked by the JNI and JVMPI.
4JavaGC CommandThe garbage collection occurred by the JavaGC command
5LastPermGCThe last garbage collection before throwing the OutOfMemoryError of permanent heap occurred.
6JHeapProf CommandThe garbage collection occurred due to the jheapprof command.
8EMReclaimFailThere was a Java heap overflow because objects were moved to the Java heap due to the explicit release of the Explicit memory.
9EMMigrateFailThere was a Java heap overflow because objects were moved to the Java heap due to the automatic release of the Explicit memory.
10JVMTIForceGCGarbage collection occurred due to the JVMTI function ForceGarbageCollection().
11PromotionFailGarbage collection occurred due to promotion failure in copy garbage collection.
12EMJavaGC CommandGarbage collection occurred due to the release of the Explicit memory block by the javagc command.
13EHeapProf CommandGarbage collection occurred due to the eheapprof command.

Examples of output

[VGC]<Wed Mar 17 00:42:30 2004>(Skip Full:0,Copy:0)[Full GC 149K->149K(1984K), 0.0786038​ secs][DefNew::Eden: 264K->0K(512K)][DefNew::Survivor: 0K->63K(64K)][Tenured: 85K->149K(1408K)][Perm: 1300K->1300K(1536K)][cause:System.gc]