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 |