NMT Memory Categories

Table 2-1 describes native memory categories used by NMT. These categories may change with the release.

Table 2-1 Native Memory Tracking Memory Categories

Category	Description
Java Heap	The heap where your objects live
Class	Class meta data
Code	Generated code
GC	data use by the GC, such as card table
Compiler	Memory used by the compiler when generating code
Symbol	Symbols
Memory Tracking	Memory used by NMT itself
Pooled Free Chunks	Memory used by chunks in the arena chunk pool
Shared space for classes	Memory mapped to class data sharing archive
Thread	Memory used by threads, including thread data structure, resource area and handle area and so on.
Thread stack	Thread stack. It is marked as committed memory, but it might not be completely committed by the OS
Internal	Memory that does not fit the previous categories, such as the memory used by the command line parser, JVMTI, properties and so on.
Unknown	When memory category can not be determined. Arena: When arena is used as a stack or value object Virtual Memory: When type information has not yet arrived