openjdk-1.8.0/8065402-G1-does-not-expand-marking-stack-when-mark-s.patch

From 21a76a7829958e0064051956d1d1f6ddb8b48650 Mon Sep 17 00:00:00 2001
From: eapen <zhangyipeng7@huawei.com>
Date: Mon, 24 Oct 2022 14:54:04 +0800
Subject: [PATCH 28/33] I68TO2: 8065402: G1 does not expand marking stack when mark
 stack overflow happens during concurrent marking
---
 .../vm/gc_implementation/g1/concurrentMark.cpp     | 22 ++++++----------------
 .../vm/gc_implementation/g1/concurrentMark.hpp     |  4 ----
 2 files changed, 6 insertions(+), 20 deletions(-)

diff --git a/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp b/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp
index 831ec94..df901a5 100644
--- a/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp
+++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp
@@ -247,7 +247,6 @@ bool CMMarkStack::allocate(size_t capacity) {
   setEmpty();
   _capacity = (jint) capacity;
   _saved_index = -1;
-  _should_expand = false;
   NOT_PRODUCT(_max_depth = 0);
   return true;
 }
@@ -256,8 +255,6 @@ void CMMarkStack::expand() {
   // Called, during remark, if we've overflown the marking stack during marking.
   assert(isEmpty(), "stack should been emptied while handling overflow");
   assert(_capacity <= (jint) MarkStackSizeMax, "stack bigger than permitted");
-  // Clear expansion flag
-  _should_expand = false;
   if (_capacity == (jint) MarkStackSizeMax) {
     if (PrintGCDetails && Verbose) {
       gclog_or_tty->print_cr(" (benign) Can't expand marking stack capacity, at max size limit");
@@ -290,13 +287,6 @@ void CMMarkStack::expand() {
   }
 }

-void CMMarkStack::set_should_expand() {
-  // If we're resetting the marking state because of an
-  // marking stack overflow, record that we should, if
-  // possible, expand the stack.
-  _should_expand = _cm->has_overflown();
-}
-
 CMMarkStack::~CMMarkStack() {
   if (_base != NULL) {
     _base = NULL;
@@ -795,8 +785,13 @@ void ConcurrentMark::reset() {


 void ConcurrentMark::reset_marking_state(bool clear_overflow) {
-  _markStack.set_should_expand();
   _markStack.setEmpty();        // Also clears the _markStack overflow flag
+
+  // Expand the marking stack, if we have to and if we can.
+  if (has_overflown()) {
+    _markStack.expand();
+  }
+
   if (clear_overflow) {
     clear_has_overflown();
   } else {
@@ -1367,11 +1362,6 @@ void ConcurrentMark::checkpointRootsFinal(bool clear_all_soft_refs) {
     set_non_marking_state();
   }

-  // Expand the marking stack, if we have to and if we can.
-  if (_markStack.should_expand()) {
-    _markStack.expand();
-  }
-
   // Statistics
   double now = os::elapsedTime();
   _remark_mark_times.add((mark_work_end - start) * 1000.0);
diff --git a/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.hpp b/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.hpp
index f78b1cb..bbd5d59 100644
--- a/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.hpp
+++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.hpp
@@ -178,7 +178,6 @@ class CMMarkStack VALUE_OBJ_CLASS_SPEC {
   NOT_PRODUCT(jint _max_depth;)   // max depth plumbed during run

   bool  _overflow;
-  bool  _should_expand;
   DEBUG_ONLY(bool _drain_in_progress;)
   DEBUG_ONLY(bool _drain_in_progress_yields;)

@@ -255,9 +254,6 @@ class CMMarkStack VALUE_OBJ_CLASS_SPEC {
   bool overflow() { return _overflow; }
   void clear_overflow() { _overflow = false; }

-  bool should_expand() const { return _should_expand; }
-  void set_should_expand();
-
   // Expand the stack, typically in response to an overflow condition
   void expand();

--
1.8.3.1