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  1. JDK
  2. JDK-8230646

Epsilon does not extend TLABs to max size

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    • gc
    • b14

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      Description

        TLAB allocation path asks collected heap about the max tlab size currently available. But, in Epsilon code, there is discrepancy: the caller interprets the returned value in bytes, while Epsilon code has the size in words. Every other GC adjusts accordingly, Epsilon should too.

        Fix:

        diff -r c8bc506106e3 src/hotspot/share/gc/epsilon/epsilonHeap.cpp
        --- a/src/hotspot/share/gc/epsilon/epsilonHeap.cpp Thu Sep 05 11:09:12 2019 +0200
        +++ b/src/hotspot/share/gc/epsilon/epsilonHeap.cpp Thu Sep 05 11:35:57 2019 +0200
        @@ -108,12 +108,12 @@
           return memory_pools;
         }
         
         size_t EpsilonHeap::unsafe_max_tlab_alloc(Thread* thr) const {
           // Return max allocatable TLAB size, and let allocation path figure out
        - // the actual TLAB allocation size.
        - return _max_tlab_size;
        + // the actual allocation size. Note: result should be in bytes.
        + return _max_tlab_size * HeapWordSize;
         }
         
         EpsilonHeap* EpsilonHeap::heap() {
           CollectedHeap* heap = Universe::heap();
           assert(heap != NULL, "Uninitialized access to EpsilonHeap::heap()");

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                  Resolved: