JDK-8204686 : Dynamic parallel reference processing support for Parallel GC
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: gc
  • Affected Version: 11
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • Submitted: 2018-06-11
  • Updated: 2021-07-21
  • Resolved: 2021-06-07
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JDK 17
17 b26Fixed
Related Reports
CSR :  
JDK-8267899 - Dynamic parallel reference processing support for Parallel GC
Relates :  
JDK-6938732 - Ergonomify (parallel) reference processing
Relates :  
JDK-8043575 - Dynamically parallelize reference processing work
Relates :  
JDK-8270908 - TestParallelRefProc fails on single core machines
Relates :  
JDK-8204951 - Investigate to use WorkGang for Parallel GC
Sub Tasks
JDK-8268105 :  
Release Note: Parallel GC Enables Adaptive Parallel Reference Processing by Default - Resolved
Description
Implement support for dynamic parallel reference processing support for parallel GC particularly because since JDK-8204951 parallel gc uses WorkGangs.
Comments
Changeset: 9fc914b9 Author: Leo Korinth <lkorinth@openjdk.org> Date: 2021-06-07 08:02:26 +0000 URL: https://git.openjdk.java.net/jdk/commit/9fc914b96321c24e14f1b52246df0b816cb7dafa
07-06-2021
Original description: During review of the dynamic parallel reference processing we found that Parallel GC support is not as trivial as expected. The way parallel gc manages worker threads is more sophisticated than expected, so we removed support for it in the first iteration. In particular, when changing number of threads, you need to supply IdleTasks to the supposedly idle threads manually. Implement support for it.
31-05-2021
JDK-8204951 changed ParallelGC to use WorkGangs as the basis for parallelism. We can remove the AbstractRefProcTaskExecutor abstraction and change reference processing to just use workgangs, at which point ParallelGC should pick up the dynamic parallel reference processing feature for free.
29-08-2019