Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8235982

AArch64: Insufficient memory barriers in shadow region algorithm

    XMLWordPrintable

Details

    • gc
    • b28
    • aarch64

    Backports

      Description

        I occasionally see this test crash on AArch64 with the following assertion failure:

        # Internal Error (/home/ent-user/ci-scripts/jdk_src/src/hotspot/share/oops/compressedOops.inline.hpp:84), pid=85650, tid=85656
        # assert(!is_null(v)) failed: narrow klass value can never be zero

        See the attached full crash log.

        Looks like there's a missing store-store barrier in parallal GC MoveAndUpdateShadowClosure::complete_region, as the stores from set_shadow_region() and mark_filled() can be reordered on a non-TSO processor.

        I'll do some more testing and send out a patch.

        Attachments

          Issue Links

            Activity

              People

                ngasson Nick Gasson
                ngasson Nick Gasson
                Votes:
                0 Vote for this issue
                Watchers:
                3 Start watching this issue

                Dates

                  Created:
                  Updated:
                  Resolved: