Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8294947

Use 64bit atomics in patch_verified_entry on x86_64

XMLWordPrintable

    • b24
    • x86_64
    • linux

        I'm working on a crash that seems to be related to CMC[1] - the JVM crashes when a method become not re-entrant because a JavaThread executing a compiled method reaches an instruction partially-assembled during patching of verified entry point.

        Unfortunately, no simple reproducer available.

        In the void NativeJump::patch_verified_entry() we atomically patch first 4 bytes, then atomically patch 5th byte, then atomically patch first 4 bytes again.

        But from CMC point of view it's better to patch atomically 8 bytes at once.

        1. http://cr.openjdk.java.net/~jrose/jvm/hotspot-cmc.html

              dsamersoff Dmitriy Samersoff
              dsamersoff Dmitriy Samersoff
              Votes:
              0 Vote for this issue
              Watchers:
              6 Start watching this issue

                Created:
                Updated:
                Resolved: