From 0ed610485661235817121f82772b92742ac3743d Mon Sep 17 00:00:00 2001
Date: Fri, 22 Jan 2021 15:20:00 +0800
Subject: 8165857: CMS _overflow_list is missing volatile
 specifiers.

Summary: <gc>: [backport of JDK-8165857][Change _overflow_list from "oop" to "oopDesc* volatile", both CMS and ParNew.]
LLT: NA
Bug url: http://hg.openjdk.java.net/jdk9/jdk9/hotspot/rev/f1ad14991f86
---
 .../concurrentMarkSweep/concurrentMarkSweepGeneration.hpp       | 2 +-
 .../src/share/vm/gc_implementation/parNew/parNewGeneration.hpp  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp
index a023b9fb9..c28f8d6c1 100644
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp
@@ -556,7 +556,7 @@ class CMSCollector: public CHeapObj<mtGC> {
 
   // Overflow list of grey objects, threaded through mark-word
   // Manipulated with CAS in the parallel/multi-threaded case.
-  oop _overflow_list;
+  oopDesc* volatile _overflow_list;
   // The following array-pair keeps track of mark words
   // displaced for accomodating overflow list above.
   // This code will likely be revisited under RFE#4922830.
diff --git a/hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.hpp b/hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.hpp
index 7685353ed..5c6b6181f 100644
--- a/hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.hpp
+++ b/hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.hpp
@@ -326,7 +326,7 @@ class ParNewGeneration: public DefNewGeneration {
   // A list of from-space images of to-be-scanned objects, threaded through
   // klass-pointers (klass information already copied to the forwarded
   // image.)  Manipulated with CAS.
-  oop _overflow_list;
+  oopDesc* volatile _overflow_list;
   NOT_PRODUCT(ssize_t _num_par_pushes;)
 
   // If true, older generation does not support promotion undo, so avoid.
-- 
2.19.0