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  1. JDK
  2. JDK-8151215

Modify layout of (large) Concurrent Mark data structures

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    • Subcomponent:
      gc

      Description

      In JDK-8077144 we noticed that a large part of startup is spent in initializing the concurrent mark data structures.

      This is because they are huge. It might be advantageous to

      - try to allocate them more lazily so that not all memory (or reservation) is actually used). A large part of the heap consists of young gen, where no mark bitmap(s) are required.
      Also, most likely, not all threads touch the bitmaps for all memory.

      - allow better blocking of the data structures so that the can be (un-)committed more easily on a region basis.

      - share some memory between threads after all (or only allow particular threads access to particular memory areas)

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