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  1. JDK
  2. JDK-8151340

aarch64: prefetch the destination word for write prior to ldxr/stxr loops

    Details

    • Type: Enhancement
    • Status: Resolved
    • Priority: P4
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 9
    • Component/s: hotspot
    • Labels:
      None
    • Subcomponent:
    • Introduced In Version:
      9
    • Resolved In Build:
      b112
    • CPU:
      aarch64
    • OS:
      linux

      Description

      As discussed in LKML: http://lists.infradead.org/pipermail/linux-arm-kernel/2015-July/355996.html, the cost of changing a cacheline from shared to exclusive state can be significant, especially when this is triggered by an exclusive store, since it may result in having to retry the transaction.

      So it's better to make use of the aarch64 "prfm" instruction to prefetch cachelines for write prior to ldxr/stxr loops.

        Activity

        Hide
        hgupdate HG Updates added a comment -
        URL: http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/9e9281592247
        User: enevill
        Date: 2016-03-08 15:57:33 +0000
        Show
        hgupdate HG Updates added a comment - URL: http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/9e9281592247 User: enevill Date: 2016-03-08 15:57:33 +0000
        Hide
        hgupdate HG Updates added a comment -
        URL: http://hg.openjdk.java.net/jdk9/jdk9/hotspot/rev/9e9281592247
        User: lana
        Date: 2016-03-30 18:38:07 +0000
        Show
        hgupdate HG Updates added a comment - URL: http://hg.openjdk.java.net/jdk9/jdk9/hotspot/rev/9e9281592247 User: lana Date: 2016-03-30 18:38:07 +0000

          People

          • Assignee:
            fyang Felix Yang
            Reporter:
            fyang Felix Yang
          • Votes:
            0 Vote for this issue
            Watchers:
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            Dates

            • Created:
              Updated:
              Resolved: