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  1. JDK
  2. JDK-8264223

CodeHeap::verify fails extra_hops assertion in fastdebug test

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    • Subcomponent:
    • Resolved In Build:
      b17
    • CPU:
      generic
    • OS:
      generic

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        Description

        When test with -XX:+VerifyCodeCache, many tests fail due to extra_hops assertion in CodeHeap::verify. hs_err is attached.

        compiler/codegen/Test6875866.java
        compiler/codegen/Test6935535.java
        compiler/codegen/Test8005033.java

        # Internal Error (/data/shihui/codes/shihui_jdk_master/src/hotspot/share/memory/heap.cpp:838), pid=1525697, tid=1525715
        # assert((count == 0) || (extra_hops < (16 + 2*count))) failed: CodeHeap: many extra hops due to optimization. blocks: 234, extra hops: 484.


        Check discussion in https://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2019-October/035508.html but didn't find where assertion (extra_hops < (16 + 2*count) comes from.

        for example, before CodeHeap free, segmap is following extrem case.
        |0|0|0|0|0|0|0|0|0|0|
        after release, it will be
        |0|1|1|1|1|1|1|1|1|1|
        and increase 9 unnecessary hop for 1 segment.



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                Assignee:
                hshi Hui Shi
                Reporter:
                hshi Hui Shi
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