JDK-8368946 : G1: Improve refinement thread activation
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: gc
  • Priority: P4
  • Status: Open
  • Resolution: Unresolved
  • Submitted: 2025-09-30
  • Updated: 2025-10-03
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Other
tbdUnresolved
Related Reports
Relates :  
JDK-8342382 - Implement JEP 522: G1 GC: Improve Throughput by Reducing Synchronization
Relates :  
JDK-8368935 - G1: Too much refinement activity after JEP 522 causing throughput regression in stress test
Description
Currently refinement is based on current mutator activity, which may cause needless re-refinement.

Actually it is only required to try to get the number of scanned cards down to a minimum just before garbage collection. The remaining time they can sit on the card table.

I.e. ideally only refine once completing just before gc. That could also fix/improve JDK-8368935.