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  1. JDK
  2. JDK-8253909

Implement detailed map file for CDS

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    Details

    • Type: Enhancement
    • Status: Resolved
    • Priority: P3
    • Resolution: Fixed
    • Affects Version/s: 16
    • Fix Version/s: 16
    • Component/s: hotspot
    • Subcomponent:
    • Resolved In Build:
      b20

      Description

      For analyzing the contents of a CDS archive, we need a "map file" that describes the archive in different levels of detail. This can be done using unified logging:

      (info = high level layout -- regions, etc)
      java -Xshare:dump -Xlog:cds+map=info:file=cds.map:none:filesize=0

      (debug = information about all metaspace objects)
      java -Xshare:dump -Xlog:cds+map=debug:file=cds.map:none:filesize=0

      (trace = values of every byte in the archive)
      java -Xshare:dump -Xlog:cds+map=trace:file=cds.map:none:filesize=0

      For example, we can use the map file for troubleshooting JDK-8253495
      (runtime/cds/DeterministicDump.java broken). We can diff two different cds.map files to see where the non-deterministic contents come from.

      See attachments for example contents of the map file.

        Attachments

        1. cds.map.debug.txt
          10 kB
        2. cds.map.info.txt
          6 kB
        3. cds.map.trace.txt
          73 kB

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              Assignee:
              iklam Ioi Lam
              Reporter:
              iklam Ioi Lam
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                Updated:
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