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  1. JDK
  2. JDK-8232533

G1 uses only a single thread for pretouching the java heap

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    • gc
    • b24

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      Description

        In some recent SPECjbb2015 runs with -XX:+AlwaysPreTouch G1 used only a single thread for pretouching hundreds of GB of Java heap which takes a long time.

        Eg.

        [0.160s][debug][gc,heap ] Running G1 PreTouch with 1 workers for 420 work units pre-touching 450971566080B.
        [136.307s][debug][gc,heap ] Running G1 PreTouch with 1 workers for 6 work units pre-touching 7046430720B.
        [140.038s][debug][gc,heap ] Running G1 PreTouch with 1 workers for 6 work units pre-touching 7046430720B.
        [144.142s][debug][gc,heap ] Running G1 PreTouch with 1 workers for 1 work units pre-touching 880803840B.
        [144.400s][debug][gc,heap ] Running G1 PreTouch with 1 workers for 1 work units pre-touching 880803840B.
        [144.867s][debug][gc,heap ] Running G1 PreTouch with 1 workers for 1 work units pre-touching 880803840B.

        Fix this regression.

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            Backport - A issue that is required to port a Bug or Feature into another product release. This issue type is generally associated with the main Bug/Feature to represent each individual release of the port. JDK-8280466 G1 uses only a single thread for pretouching the java heap

            • P3 - Major loss of function.
            • Resolved

            Backport - A issue that is required to port a Bug or Feature into another product release. This issue type is generally associated with the main Bug/Feature to represent each individual release of the port. JDK-8293407 G1 uses only a single thread for pretouching the java heap

            • P3 - Major loss of function.
            • Resolved
            relates to

            Enhancement - null JDK-8252221 Use multiple workers for Parallel GC pre-touching

            • P4 - Minor loss of function, or other problem where easy workaround is present.
            • Resolved
            links to

            Commit Commit openjdk/jdk11u-dev/914d48cb

            Review Review openjdk/jdk11u-dev/751

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                sangheki Sangheon Kim
                tschatzl Thomas Schatzl
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                  Updated:
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