JDK-8040006 : Merge "Other" time parallel phases into a single
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: gc
  • Affected Version: 8u40,9
  • Priority: P4
  • Status: Open
  • Resolution: Unresolved
  • Submitted: 2014-04-11
  • Updated: 2019-02-11
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Other
tbdUnresolved
Related Reports
Relates :  
JDK-8057000 - Increase parallelism in String deduplication fixup
Relates :  
JDK-8019342 - G1: High "Other" time most likely due to card redirtying
Relates :  
JDK-8078117 - Refactor enqueue_discovered_references() and redirty_logged_cards() to share the same work gang.
Relates :  
JDK-8034842 - Parallelize the Free CSet phase in G1
Relates :  
JDK-8037956 - Merge String Deduplication work with String/Symbol table work
Relates :  
JDK-8029075 - String deduplication in G1
Description
Recently a few parts of the "Other" time (and actually there are phases outside "Other" that are already parallelized) were parallelized, each using its own gangtask.

To avoid the constant startup/termination synchronization of the gang threads, try to merge the work into a single (or an appropriate amount of) gangs.

I added a few CRs that added gang tasks that could be considered for that work.
Comments
Obvious candidates (at this time) are work by the WeakProcessor and the card table clearing (remembered set cleanup).
24-01-2019
The G1ParallelCleaningTask is an example of multiple tasks done with a single gang.
14-04-2015