JDK-8035406 : Improve data structure for Code Cache remembered sets
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: gc
  • Affected Version: 8u20,9
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • Submitted: 2014-02-20
  • Updated: 2022-01-31
  • Resolved: 2014-03-17
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JDK 8 JDK 9
8u20Fixed 9 b08Fixed
Related Reports
Relates :  
JDK-8039839 - G1: TestCodeCacheRemSet_test() fails intermittently
Relates :  
JDK-8280932 - G1: Rename HeapRegionRemSet::_code_roots accessors
Relates :  
JDK-8025813 - G1: Code root marking unbalanced
Relates :  
JDK-7145569 - G1: optimize nmethods scanning
Relates :  
JDK-8038930 - G1CodeRootSet::test fails with assert(_num_chunks_handed_out == 0) failed: No elements must have been handed out yet
Description
In JDK-7145569 per region remembered sets for code cache roots were introduced.

The data structure for this was a simple GrowableArray. Measurements for JDK-8027295 have shown that reclaiming them is a serious performance bottleneck.

Also JDK-8025813 G1: Code root marking unbalanced requires a better data structure that is more amenable to parallelize.

The idea is to change the GrowableArray into a list of chunks containing the nmethod references.
Comments
URL: http://hg.openjdk.java.net/jdk9/jdk9/hotspot/rev/7c383fe0d35a User: lana Date: 2014-04-09 18:28:01 +0000
09-04-2014
URL: http://hg.openjdk.java.net/jdk9/hs-gc/hotspot/rev/7c383fe0d35a User: tschatzl Date: 2014-03-17 13:02:06 +0000
17-03-2014