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  1. JDK
  2. JDK-7065535

Mistyped function name that disabled UseLargePages on Windows

    Details

    • Subcomponent:
    • Introduced In Build:
      b01
    • Introduced In Version:
    • Resolved In Build:
      b06
    • CPU:
      generic
    • OS:
      windows_2000

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        Description

        Hotspot dynamically loads advapi32.dll and discovers LookupPrivilegeValue function for enabling UseLargePages commandline option. However, LookupPrivilegeValue has two versions, LookupPrivilegeValueA and LookupPrivilegeValueW. For Hotspot, it should use LookupPrivilegeValueA version.

        6u27 missed "A" at the end of function name, that caused function can not be allocated, which will disable "UseLargePages" option.

        This can be the root that causes 9% performance regression on SPECjbb2005, discovered by Intel.
        Be aware, UseLargePages commandline option requires a special security permission on local machine, please refer to comments in os_windows.cpp for how to set it up.

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                • Assignee:
                  zgu Zhengyu Gu
                  Reporter:
                  zgu Zhengyu Gu
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