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  1. JDK
  2. JDK-8151340

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

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Details

    • Enhancement
    • Resolution: Fixed
    • P4
    • 9
    • None
    • hotspot
    • None
    • 9
    • b112
    • aarch64
    • linux

    Backports

      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.

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            backported by

            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-8260763 aarch64: prefetch the destination word for write prior to ldxr/stxr loops

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

            Enhancement - null JDK-8257192 Integrate AArch64 JIT port into 8u

            • P3 - Major loss of function.
            • Resolved

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                fyang Fei Yang
                fyang Fei Yang
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                Dates

                  Created:
                  Updated:
                  Resolved: