hg: jdk/submit14: 8235982: AArch64: Insufficient memory barriers in shadow region algorithm

[thomas.schatzl at oracle.com]

Changeset: 153bd98146fc
Author:    ngasson
Date:      2019-12-18 11:20 +0100
URL:       https://hg.openjdk.java.net/jdk/submit14/rev/153bd98146fc

8235982: AArch64: Insufficient memory barriers in shadow region algorithm
Summary: The memory barriers used for synchronizing ParallelCompactData::RegionData::_shadow_state and ParallelCompactData::RegionData::shadow_region are insufficient to prevent reordering of loads.
Reviewed-by: tschatzl, sjohanss

! src/hotspot/share/gc/parallel/psParallelCompact.hpp