JDK-8137280 : Remove eager reclaim of humongous controls
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: gc
  • Affected Version: 9
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • OS: generic
  • CPU: generic
  • Submitted: 2015-09-28
  • Updated: 2022-07-14
  • Resolved: 2022-07-07
The Version table provides details related to the release that this issue/RFE will be addressed.

Unresolved : Release in which this issue/RFE will be addressed.
Resolved: Release in which this issue/RFE has been resolved.
Fixed : Release in which this issue/RFE has been fixed. The release containing this fix may be available for download as an Early Access Release or a General Availability Release.

To download the current JDK release, click here.
JDK 20
20 b06Fixed
Related Reports
Relates :  
JDK-8273882 - Only enable preventive garbage collections if humongous eager reclaim is enabled
Relates :  
JDK-8027959 - Early reclamation of large objects in G1
Description
The options G1EagerReclaimHumongousObjects and G1EagerReclaimHumongousObjectsWithStaleRefs are presently defined as experimental, but are enabled by default.

The features being controlled have been enabled for a number of months without causing problems, so that we no longer consider the associated features to be experimental.  So it's time to remove the options.
Comments
Changeset: 013a5eee Author: Albert Mingkun Yang <ayang@openjdk.org> Date: 2022-07-07 13:53:24 +0000 URL: https://git.openjdk.org/jdk/commit/013a5eeeb9d9a46778f68261ac69ed7235cdc7dd
07-07-2022
A pull request was submitted for review. URL: https://git.openjdk.org/jdk/pull/9392 Date: 2022-07-06 08:12:32 +0000
06-07-2022
+1 for removing the flags =)
06-05-2021
While the flags are experimental and can be removed easily, a release note would be nice anyway.
06-05-2021
From a discussion with [~sjohanss]: "we will keep collecting eager reclaim candidates even if we run with -XX:-G1EagerReclaimHumongousObjects since our is_potential_eager_reclaim_candidate() first check the WithStaleRefs flag. So to disable eager reclaim candidate search we need to disable two flags… but only the first is needed to then not do anything with the candidates" Since disabling humongous eager reclaim is kind-of broken anyway, apparently it has been working fine for a long time...
06-05-2021
There is actually an argument about not removing these options, JDK-8141637 shows that disabling eager humongous reclamation may be useful.
10-11-2015