-XX:[+|-]HitachiVerboseGC (Option for extended verbosegc information output)

Format

-XX:+HitachiVerboseGC
When garbage collection occurs, this option outputs the extended verbosegc information to the JavaVM log file.
This option outputs the information of Eden, Survivor, Tenured, and Perm kinds that form the internal areas of garbage collection, as the extended verbosegc information.
-XX:-HitachiVerboseGC
When garbage collection occurs, this option does not output the extended verbosegc information to the JavaVM log file.

Description

Specify whether to output the extended verbosegc information when garbage collection occurs.

Default value
  • -XX:-HitachiVerboseGC

Output format

[id] date (Skip Full:full_count, Copy:copy_count) [gc_kind gc_info, gc_time secs][Eden: eden_info][Survivor: survivor_info][Tenured: tenured_info][Perm: perm_info] [cause:cause_info] [User: user_cpu secs] [Sys: system_cpu secs] [CCI: cc_used_sizeK, cc_max_sizeK, cc_infoK]

The following is a description of the output contents:

id
VGC (Identifier of the JavaVM log file)
date
Indicates the date and time for starting garbage collection.
When the -XX:-HitachiVerboseGCPrintDate option is specified, the date is not output.
full_count
Indicates the number of times the output of full GC information is skipped.
This is output when the -XX:HitachiVerboseGCIntervalTime option is specified.
copy_count
Indicates the number of times the output of copy GC information is skipped.
This is output when the -XX:HitachiVerboseGCIntervalTime option is specified.
gc_kind
Indicates the garbage collection type. "FullGC" or "GC" is output.
gc_info
Indicates the garbage collection information. The information is output in the following format:

area-length-before-the-garbage-collection -> area-length-after-the-garbage-collection (area-size)

gc_time
Indicates the elapsed time for garbage collection.
Eden
Indicates the type of eden. "DefNew::Eden" or "ParNew::Eden" is output.
eden_info
Indicates the Eden information. The information is output in the following format:

area-length-before-the-garbage-collection -> area-length-after-the-garbage-collection (area-size)

Servivor
Indicates the survivor type. "DefNew:: Survivor" or "ParNew::Survivor" is output.
survivor_info
Indicates the Survivor information. The information is output in the following format:

area-length-before-the-garbage-collection -> area-length-after-the-garbage-collection (area-size)

Tenured
Indicates the type of Tenured. "Tenured" is output.
tenured_info
Indicates the Tenured information. The information is output in the following format:

area-length-before-the-garbage-collection -> area-length-after-the-garbage-collection (area-size)

Perm
Indicates the type of Perm. "Perm" is output.
perm_info
Indicates the Perm information. The information is output in the following format:

area-length-before-the-garbage-collection -> area-length-after-the-garbage-collection (area-size)

cause_info
Indicates the cause of garbage collection.
When the -XX:-HitachiVerboseGCPrintCause option is specified, this information is not output.
user_cpu
Indicates the CPU time that the garbage collection thread has consumed in the user mode. The unit is in seconds.
If the -XX:+UseParNewGC option is specified, user_cpu becomes the total CPU time spent in the user mode by all the garbage collection threads.
If an attempt to obtain the CPU time fails, unknown is displayed as in the case of [User: unknown].
When the -XX:-HitachiVerboseGCCpuTime option is specified, the information is not output.
system_cpu
Indicates the CPU time that the garbage collection thread has consumed in the kernel mode. The unit is in seconds.
If the -XX:+UseParNewGC option is specified, system_cpu becomes the total CPU time spent by all the garbage collection threads in the kernel mode.
If an attempt to obtain the CPU time, unknown is displayed as in the case of [Sys: unknown].
When the -XX:-HitachiVerboseGCCpuTime option is specified, the information is not output.
jvm_alloc_size
Specifies the size of the area currently in use, from the areas being managed in JavaVM (size of the area currently in use, from the total size of mmap_total_size and malloc_total_size).
When the -XX:HitachiVerboseGCPrintJVMInternalMemory option is specified, this information is not output.
mmap_total_size
Specifies the total C heap size allocated for mmap (VirtualAlloc in Windows), from the areas being managed in JavaVM.
When the -XX:-HitachiVerboseGCPrintJVMInternalMemory option is specified, this information is not output.
malloc_total_size
Specifies the total C heap size allocated for malloc, from the areas being managed in JavaVM.
When the -XX:-HitachiVerboseGCPrintJVMInternalMemory option is specified, this information is not output.
thread_count
Specifies the number of Java threads.
When the -XX:-HitachiVerboseGCPrintThreadCount option is specified, this information is not output.
doe_alloc_size
Specifies the cumulative heap size allocated by invoking the java.io.File.deleteOnExit()method.
When the -XX:-HitachiVerboseGCPrintDeleteOnExit option is specified, this information is not output.
called_count
Specifies the invocation count of the java.io.File.deleteOnExit() method.
When the -XX:-HitachiVerboseGCPrintDeleteOnExit option is specified, this information is not output.
cc_used_size
Specifies the size of the code cache area used when the garbage collection occurs. The unit is kilobyte.
When the -XX:-PrintCodeCacheInfo option is specified, this information is not output.
cc_max_size
Specifies the maximum size of the code cache area. The unit is kilobyte.
When the -XX:-PrintCodeCacheInfo option is specified, this information is not output.
cc_info
Specifies the maintenance information.
When the -XX:-PrintCodeCacheInfo option is specified, this information is not output.

Examples of output