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  1. JDK
  2. JDK-8159429

Contention on FreeList_lock during allocating GC regions

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    • Subcomponent:
      gc

      Description

      Running some micro benchmarks with lock tracing in the Oracle Studio analyzer show a significant amount of time spent in stack traces (i.e. actual cpu time plus much sync wait time) with G1Allocator::par_allocate_during_gc() holding a lock. This amounts to around 5-10% of evacuation, and almost all sync wait time.

      This is most likely the FreeList_lock grabbed before the call to G1AllocRegion::attempt_allocation_locked().

      Investigate, and try to improve.

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              • Assignee:
                Unassigned
                Reporter:
                tschatzl Thomas Schatzl
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                • Created:
                  Updated: