JDK-8186042 : Optimize OopMapCache lookup
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: runtime
  • Affected Version: 10
  • Priority: P3
  • Status: Resolved
  • Resolution: Fixed
  • Submitted: 2017-08-09
  • Updated: 2024-07-18
  • Resolved: 2017-08-28
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JDK 10
10 b22Fixed
Related Reports
CSR :  
JDK-8186091 - Optimize OopMapCache lookup
Relates :  
JDK-8331572 - Allow using OopMapCache outside of STW GC phases
Relates :  
JDK-8160539 - Stack frame scanning acquires DerivedPointerTableGC_lock mutex
Description
The OopMapCache::lookup function that returns the oopMap for a specific (Method, bci) takes out a Mutex to lookup for each entry on the stack.

The OopMapCache holds bitmaps to indicate where oops are in the locals and expression stack for a method at bci for interpreter frames found on the stack during GC.

Lock free access speeds up GC root processing for thread stacks.
Comments
URL: http://hg.openjdk.java.net/jdk10/jdk10/hotspot/rev/c5c6aa319333 User: jwilhelm Date: 2017-08-29 22:57:33 +0000
29-08-2017
URL: http://hg.openjdk.java.net/jdk10/hs/hotspot/rev/c5c6aa319333 User: coleenp Date: 2017-08-28 16:16:37 +0000
28-08-2017
For testing, I changed the TraceOopMapGeneration option to use logging, so would like to remove TraceOopMapGeneration option since I have to wonder if I'm the only one that's ever used it.
10-08-2017