Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8320807

[PPC64][ZGC] C1 generates wrong code for atomics

    XMLWordPrintable

Details

    • gc
    • b27
    • ppc

    Backports

      Description

        The test java/lang/Thread/virtual/stress/Skynet.java#ZGenerational often hangs or throws RejectedExecutionException: Queue capacity exceeded.
        The issue occurs only when C1 is enabled. "-XX:DisableIntrinsic=_getAndSetReference" was found as possible workaround.
        Further analysis shows that atomic_xchg_at_resolved generates wrong code because it calls xchg with colliding registers which are not handled correctly in the PPC64 code. In addition, memory barriers are missing because PPC64 code currently adds them in LIR instead of in the assembler.

        Attachments

          Issue Links

            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-8322099 [PPC64][ZGC] C1 generates wrong code for atomics

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

            Enhancement - null JDK-8300247 Harden C1 xchg on AArch64 and PPC

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

            Commit Commit openjdk/jdk21u-dev/0106db07

            Commit Commit openjdk/jdk/3087e14c

            Review Review openjdk/jdk21u-dev/4

            Review Review openjdk/jdk/16835

            Activity

              People

                mdoerr Martin Doerr
                mdoerr Martin Doerr
                Votes:
                0 Vote for this issue
                Watchers:
                3 Start watching this issue

                Dates

                  Created:
                  Updated:
                  Resolved: