JDK-8247748 : Investigate default alpha for G1 adaptive IHOP allocation rate
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: gc
  • Affected Version: 16
  • Priority: P4
  • Status: Open
  • Resolution: Unresolved
  • Submitted: 2020-06-17
  • Updated: 2020-08-17
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.
Other
tbdUnresolved
Related Reports
Relates :  
JDK-8238163 - Improve G1 Adaptive IHOP heuristics
Description
Currently G1 uses an alpha of 0.95 for its adaptive IHOP allocation rate calculation, i.e. the latest value is weighed at 95%.

Behavior seems to be the same with the default value; in order to reduce the amount of magic numbers I propose to use the default 0.7 instead for now.

There is no good explanation of why, and the original change does not clarify either. Investigate whether a better value can be found.