NativeMemoryTracking查看java内存信息

默认该功能是禁用的，因为会损失5-10%的性能

开启命令

-XX:NativeMemoryTracking=detail

打印命令

jcmd 45064 VM.native_memory summary scale=MB > NativeMemoryTracking.log

具体的日志信息

➜  ~
➜  ~ jcmd 45064 VM.native_memory summary scale=MB
45064:Native Memory Tracking:(Omitting categories weighting less than 1MB)Total: reserved=5676MB, committed=654MBmalloc: 58MB #363115mmap:   reserved=5618MB, committed=596MB-                 Java Heap (reserved=4096MB, committed=200MB)(mmap: reserved=4096MB, committed=200MB)-                     Class (reserved=1025MB, committed=11MB)(classes #16551)(  instance classes #15574, array classes #977)(malloc=1MB #44456)(mmap: reserved=1024MB, committed=10MB)(  Metadata:   )(    reserved=64MB, committed=63MB)(    used=62MB)(    waste=1MB =0.90%)(  Class space:)(    reserved=1024MB, committed=10MB)(    used=9MB)(    waste=0MB =3.79%)-                    Thread (reserved=258MB, committed=258MB)(thread #129)(stack: reserved=258MB, committed=258MB)-                      Code (reserved=50MB, committed=19MB)(malloc=2MB #10874)(mmap: reserved=48MB, committed=17MB)-                        GC (reserved=130MB, committed=54MB)(malloc=17MB #9999)(mmap: reserved=112MB, committed=36MB)-                  Internal (reserved=1MB, committed=1MB)(malloc=1MB #18262)-                    Symbol (reserved=26MB, committed=26MB)(malloc=22MB #218120)(arena=4MB #1)-    Native Memory Tracking (reserved=6MB, committed=6MB)(tracking overhead=6MB)-        Shared class space (reserved=16MB, committed=13MB, readonly=0MB)(mmap: reserved=16MB, committed=13MB)-           Synchronization (reserved=3MB, committed=3MB)(malloc=3MB #50578)-                 Metaspace (reserved=64MB, committed=63MB)(mmap: reserved=64MB, committed=63MB)

堆外内存异常问题排查

https://www.cnblogs.com/duanxz/p/3738858.html

Native Memory Tracking 详解（1）:基础介绍 | HeapDump性能社区