JDK-8338689 : Regression in SPECjvm2008-Compress-ParGC on Linux-x64 after JDK-8333962
  • Type: Bug
  • Component: hotspot
  • Sub-Component: gc
  • Affected Version: 24
  • Priority: P3
  • Status: Closed
  • Resolution: Won't Fix
  • OS: linux
  • CPU: x86_64
  • Submitted: 2024-08-20
  • Updated: 2024-08-26
  • Resolved: 2024-08-26
Related Reports
Relates :  
JDK-8338977 - Parallel: Improve heap resizing heuristics
Relates :  
JDK-8333962 - Obsolete OldSize
Description
With the introduction of JDK-8333962...

-3.5% SPECjvm2008-Compress-ParGC on Linux-x64

The regression was isolated to jdk-24+3-190
Comments
The SPECjvm2008-Compress score is very sensitive to gc-frequency/young-gen-size. All those regression patches reduces gc-pause slightly, which enables Parallel to reduce young-gen-size while maintaining the original app-time-percent. One can use two workarounds to get back the original perf: 1. increase `GCTimeRatio` 2. disable `UseAdaptiveSizePolicyFootprintGoal`. (This kind of reflects one drawback of current way of calculating app-time-percent -- it doesn't take gc-frequency into account.) JDK-8338977 aims to restore the out-of-the-box perf.
26-08-2024
[~ayang] I assigned this to you.
20-08-2024