JDK-6896099 : Integrate CMS heap ergo with default heap sizing ergo
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: gc
  • Affected Version: hs17
  • Priority: P3
  • Status: Closed
  • Resolution: Fixed
  • OS: generic
  • CPU: generic,x86
  • Submitted: 2009-10-28
  • Updated: 2013-11-01
  • Resolved: 2011-04-24
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 7 Other
7Fixed hs21Fixed
Related Reports
Duplicate :  
Relates :  
Relates :  
Relates :  
Relates :  
CMS heap ergo should be integrated with the default heap sizing ergo.  Right now
CMS ergo is a world unto itself.  Default heap sizing should run first, then
CMS should modify it to suit itself.

EVALUATION http://hg.openjdk.java.net/jdk7/hotspot-comp/hotspot/rev/dde920245681

EVALUATION http://hg.openjdk.java.net/jdk7/hotspot-rt/hotspot/rev/dde920245681

EVALUATION http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/dde920245681

PUBLIC COMMENTS This CR should be release-noted. Doc-writer, please use the following text, suitably word-smithed to provide suitable verbage in release notes:- The default out-of-the-box heap size and shape parameters for the concurrent mark sweep collector (CMS) have been modified to take advantage of the faster platforms since JDK 6 was released when these settings were last changed. Like the other collectors in HotSpot, CMS will now use the available physical memory on the platform to size its heap, while attempting to shape that heap so as to keep pause times associated with minor collections "reasonable". The specific shape of the heap may be platform-dependent in other ways as well. Users can override all or some of these default settings by means of explicitly sizing or shaping the heap, aka "heap tuning", to suit their specific needs. At this point, please point to the heap tuning guide which will also be updated to describe the default settings for this and other collectors.