Liveset information for Old Object sample event

[Markus Gronlund]

Hi Erik,

Looks good.

Thanks
Markus

-----Original Message-----
From: Erik Gahlin 
Sent: den 19 juni 2018 17:58
To: hotspot-jfr-dev at openjdk.java.net
Cc: hotspot-gc-dev at openjdk.java.net
Subject: Liveset information for Old Object sample event

Hi,

Could I have a review of an enhancement that adds heap usage after GC to the Old Object Sample (OOS) event. This is useful for spotting an increasing liveset.

Recordings typically only contain data for a limited period, i .e. last
30 minutes, but the OOS event contains samples from when JFR/JVM was started, potentially several days back.

The liveset trend is useful for tools such as Mission Control to detect if there is a memory leak. If that is the case, information in the OOS event can be used to pinpoint where the leak occurred and what is keeping it alive. Presenting this information when there is not memory leak is confusing.

Bug:
https://bugs.openjdk.java.net/browse/JDK-8197425

Webrev:
http://cr.openjdk.java.net/~egahlin/8197425/

Testings:
Tests in test/jdk/jdk/jfr

Thanks
Erik