[master] RFR: 8264311: Heap object statistics [v3]

Roman Kennke rkennke at openjdk.java.net
Fri May 7 10:33:30 UTC 2021

> For Lilliput evaluation, it would be useful to be able to get some statistics about heap objects, e.g. how many objects there typically are, what is their (average) size, how big is the live data set, how many objecs have an identity hash code and how many objects are locked. Some of that information may be useful for general purpose too, e.g. the avg live data set and object size/count information might be quite useful to have.
> Heap object statistics can be gathered and printed by invoking java with -XX:+UnlockDiagnosticVMOptions -XX:+HeapObjectStats -Xlog:heap+stats. It will impact performance of the workload. The sampling interval can be specificed by -XX:HeapObjectStatsSamplingInterval=X (in ms) and defaults to 500 (ms).
> Testing:
>  - [x] Some manual tests, verifying the plausability of the output by hand
>  - [x] tier1
>  - [x] tier2

Roman Kennke has updated the pull request incrementally with one additional commit since the last revision:

  Remove unused variable/statement


  - all: https://git.openjdk.java.net/lilliput/pull/1/files
  - new: https://git.openjdk.java.net/lilliput/pull/1/files/2dccd22e..379caeca

 - full: https://webrevs.openjdk.java.net/?repo=lilliput&pr=1&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=lilliput&pr=1&range=01-02

  Stats: 2 lines in 2 files changed: 0 ins; 1 del; 1 mod
  Patch: https://git.openjdk.java.net/lilliput/pull/1.diff
  Fetch: git fetch https://git.openjdk.java.net/lilliput pull/1/head:pull/1

PR: https://git.openjdk.java.net/lilliput/pull/1

More information about the lilliput-dev mailing list