From ce63583ff5d33e6d8557d3e76d6253cb4e37f4e2 Mon Sep 17 00:00:00 2001
From: Afshin Zafari <Afshin.zafari@oracle.com>
Date: Thu, 29 Jan 2026 13:03:45 +0100
Subject: [PATCH] improved the VMR ctor for committed regions

---
 src/hotspot/share/nmt/regionsTree.hpp          | 11 ++++++++++-
 src/hotspot/share/nmt/regionsTree.inline.hpp   |  8 ++++++--
 src/hotspot/share/nmt/virtualMemoryTracker.hpp |  8 ++++----
 3 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/src/hotspot/share/nmt/regionsTree.hpp b/src/hotspot/share/nmt/regionsTree.hpp
index 6a9aac1113c..ef79a6505ab 100644
--- a/src/hotspot/share/nmt/regionsTree.hpp
+++ b/src/hotspot/share/nmt/regionsTree.hpp
@@ -70,6 +70,7 @@ class RegionsTree : public VMATree {
         return position() - other.position();
       }
       inline NativeCallStackStorage::StackIndex out_stack_index() const { return _node->val().out.reserved_stack(); }
+      inline NativeCallStackStorage::StackIndex out_committed_stack_index() const { return _node->val().out.committed_stack(); }
       inline MemTag in_tag() const { return _node->val().in.mem_tag(); }
       inline MemTag out_tag() const { return _node->val().out.mem_tag(); }
       inline void set_in_tag(MemTag tag) { _node->val().in.set_tag(tag); }
@@ -89,7 +90,7 @@ class RegionsTree : public VMATree {
     return RegionData(_ncs_storage.push(ncs), tag);
   }
 
-  inline const NativeCallStack stack(NodeHelper& node) {
+  inline const NativeCallStack reserved_stack(NodeHelper& node) {
     if (!_with_storage) {
       return NativeCallStack::empty_stack();
     }
@@ -97,6 +98,14 @@ class RegionsTree : public VMATree {
     return _ncs_storage.get(si);
   }
 
+  inline const NativeCallStack committed_stack(NodeHelper& node) {
+    if (!_with_storage) {
+      return NativeCallStack::empty_stack();
+    }
+    NativeCallStackStorage::StackIndex si = node.out_committed_stack_index();
+    return _ncs_storage.get(si);
+  }
+
   size_t committed_size(const VirtualMemoryRegion& rgn);
 };
 
diff --git a/src/hotspot/share/nmt/regionsTree.inline.hpp b/src/hotspot/share/nmt/regionsTree.inline.hpp
index b2c3b21279b..820ac90d88b 100644
--- a/src/hotspot/share/nmt/regionsTree.inline.hpp
+++ b/src/hotspot/share/nmt/regionsTree.inline.hpp
@@ -38,7 +38,11 @@ void RegionsTree::visit_committed_regions(const VirtualMemoryRegion& rgn, F func
   visit_range_in_order(start, end, [&](Node* node) {
     NodeHelper curr(node);
     if (prev.is_valid() && prev.is_committed_begin()) {
-      VirtualMemoryRegion cmr((address)prev.position(), curr.distance_from(prev), stack(prev), true /*committed*/);
+      VirtualMemoryRegion cmr((address)prev.position(),
+                              curr.distance_from(prev),
+                              reserved_stack(prev),
+                              committed_stack(prev),
+                              prev.out_tag());
       if (!func(cmr)) {
         return false;
       }
@@ -63,7 +67,7 @@ void RegionsTree::visit_reserved_regions(F func) {
     }
     prev = curr;
     if (curr.is_released_begin() || begin_node.out_tag() != curr.out_tag()) {
-      auto st = stack(begin_node);
+      auto st = reserved_stack(begin_node);
       if (rgn_size == 0) {
         prev.clear_node();
         return true;
diff --git a/src/hotspot/share/nmt/virtualMemoryTracker.hpp b/src/hotspot/share/nmt/virtualMemoryTracker.hpp
index bd87ae398c1..1486075131d 100644
--- a/src/hotspot/share/nmt/virtualMemoryTracker.hpp
+++ b/src/hotspot/share/nmt/virtualMemoryTracker.hpp
@@ -214,10 +214,10 @@ class VirtualMemoryRegion {
      assert(size > 0, "Invalid size");
   }
 
-  VirtualMemoryRegion(address addr, size_t size, const NativeCallStack& stack, bool committed) :
-    _base_address(addr), _size(size), _mem_tag(mtNone),
-    _reserved_stack(NativeCallStack::empty_stack()) ,
-    _committed_stack(stack) {
+  VirtualMemoryRegion(address addr, size_t size, const NativeCallStack& reserved_stack, const NativeCallStack& committed_stack, MemTag mem_tag = mtNone) :
+    _base_address(addr), _size(size), _mem_tag(mem_tag),
+    _reserved_stack(reserved_stack),
+    _committed_stack(committed_stack) {
      assert(addr != nullptr, "Invalid address");
      assert(size > 0, "Invalid size");
   }