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  1. JDK
  2. JDK-8245106

ZGC: Fix incorrect setup when using -XX:+UseTransparentHugePages

    Details

    • Type: Bug
    • Status: Closed
    • Priority: P2
    • Resolution: Fixed
    • Affects Version/s: 15
    • Fix Version/s: 15
    • Component/s: hotspot
    • Labels:
    • Subcomponent:
      gc
    • Resolved In Build:
      b24
    • Verification:
      Verified

      Description

      When using -XX:+UseTransparentHugePages, ZGC mistakenly calls madvise(..., MADV_HUGE); too late. The end result is that large pages are never allocated on first page fault, only via THP defrag. This in turn means that the majority of the heap will typically not be backed by large pages, which can have a very noticeable performance impact.

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              • Assignee:
                pliden Per Liden
                Reporter:
                pliden Per Liden
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                • Created:
                  Updated:
                  Resolved: