RFR: 8287135: Calculation of jmm_GetMemoryUsage is wrong

Mon May 23 07:37:16 UTC 2022

It seems that calculation of MemoryMXBean.getNonHeapMemoryUsage(jmm_GetMemoryUsage) is wrong.

Currently, NonHeapUsage = CodeCache + Metaspace + CompressedClassSpace

==> CodeHeap 'non-nmethods' 1532544 (Used)
==> CodeHeap 'profiled nmethods' 0
==> CodeHeap 'non-profiled nmethods' 13952
==> Metaspace 506696
==> Compressed Class Space 43312
init = 7667712(7488K) used = 2096504(2047K) committed = 8454144(8256K) max = -1(-1K)

In this way, getNonHeapMemoryUsage is larger than it ought to be, it should be NonHeapUsage = CodeCache + Metaspace.

-------------

Commit messages:
 - 8287135 Calculation of jmm_GetMemoryUsage is wrong

Changes: https://git.openjdk.java.net/jdk/pull/8831/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8831&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8287135
  Stats: 10 lines in 2 files changed: 9 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8831.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8831/head:pull/8831

PR: https://git.openjdk.java.net/jdk/pull/8831