--- a/src/hotspot/share/prims/whitebox.cpp	Fri Feb 08 10:03:07 2019 -0800
+++ b/src/hotspot/share/prims/whitebox.cpp	Fri Feb 08 14:03:09 2019 -0500
@@ -694,6 +694,13 @@
   return (jlong)(uintptr_t)os::malloc(size, mtTest, stack);
 WB_END
 
+// Alloc memory with pseudo call stack and specific memory type.
+WB_ENTRY(jlong, WB_NMTMallocWithPseudoStackAndType(JNIEnv* env, jobject o, jlong size, jint pseudo_stack, jint type))
+  address pc = (address)(size_t)pseudo_stack;
+  NativeCallStack stack(&pc, 1);
+  return (jlong)(uintptr_t)os::malloc(size, (MEMFLAGS)type, stack);
+WB_END
+
 // Free the memory allocated by NMTAllocTest
 WB_ENTRY(void, WB_NMTFree(JNIEnv* env, jobject o, jlong mem))
   os::free((void*)(uintptr_t)mem);
@@ -2161,6 +2168,7 @@
 #if INCLUDE_NMT
   {CC"NMTMalloc",           CC"(J)J",                 (void*)&WB_NMTMalloc          },
   {CC"NMTMallocWithPseudoStack", CC"(JI)J",           (void*)&WB_NMTMallocWithPseudoStack},
+  {CC"NMTMallocWithPseudoStackAndType", CC"(JII)J",   (void*)&WB_NMTMallocWithPseudoStackAndType},
   {CC"NMTFree",             CC"(J)V",                 (void*)&WB_NMTFree            },
   {CC"NMTReserveMemory",    CC"(J)J",                 (void*)&WB_NMTReserveMemory   },
   {CC"NMTAttemptReserveMemoryAt",    CC"(JJ)J",       (void*)&WB_NMTAttemptReserveMemoryAt },

--- a/src/hotspot/share/services/memReporter.cpp	Fri Feb 08 10:03:07 2019 -0800
+++ b/src/hotspot/share/services/memReporter.cpp	Fri Feb 08 14:03:09 2019 -0500
@@ -704,9 +704,15 @@
 
 void MemDetailDiffReporter::diff_malloc_site(const MallocSite* early,
   const MallocSite* current)  const {
-  assert(early->flag() == current->flag(), "Must be the same memory type");
-  diff_malloc_site(current->call_stack(), current->size(), current->count(),
-    early->size(), early->count(), early->flag());
+  if (early->flag() != current->flag()) {
+    // If malloc site type changed, treat it as deallocation of old type and
+    // allocation of new type.
+    old_malloc_site(early);
+    new_malloc_site(current);
+  } else {
+    diff_malloc_site(current->call_stack(), current->size(), current->count(),
+      early->size(), early->count(), early->flag());
+  }
 }
 
 void MemDetailDiffReporter::diff_malloc_site(const NativeCallStack* stack, size_t current_size,

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/NMT/MallocSiteTypeChange.java	Fri Feb 08 14:03:09 2019 -0500
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2019, Red Hat, Inc. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+/*
+ * @test MallocSiteTypeChange
+ * @bug 8200109
+ * @key nmt jcmd
+ * @modules java.base/jdk.internal.misc
+ * @library /test/lib
+ * @build sun.hotspot.WhiteBox
+ * @run driver ClassFileInstaller sun.hotspot.WhiteBox
+ * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -XX:NativeMemoryTracking=detail MallocSiteTypeChange
+ */
+
+import jdk.test.lib.JDKToolFinder;
+import jdk.test.lib.process.ProcessTools;
+import jdk.test.lib.process.OutputAnalyzer;
+import sun.hotspot.WhiteBox;
+
+public class MallocSiteTypeChange {
+    public static void main(String args[]) throws Exception {
+        OutputAnalyzer output;
+        WhiteBox wb = WhiteBox.getWhiteBox();
+
+        // Grab my own PID
+        String pid = Long.toString(ProcessTools.getProcessId());
+        ProcessBuilder pb = new ProcessBuilder();
+
+        int pc = 1;
+        long addr = wb.NMTMallocWithPseudoStack(4 * 1024, pc);
+
+        // Verify that current tracking level is "detail"
+        pb.command(new String[] { JDKToolFinder.getJDKTool("jcmd"), pid, "VM.native_memory", "summary"});
+        output = new OutputAnalyzer(pb.start());
+        output.shouldContain("Test (reserved=4KB, committed=4KB)");
+
+        pb.command(new String[] { JDKToolFinder.getJDKTool("jcmd"), pid, "VM.native_memory", "baseline"});
+        output = new OutputAnalyzer(pb.start());
+        output.shouldContain("Baseline succeeded");
+
+        wb.NMTFree(addr);
+        addr = wb.NMTMallocWithPseudoStackAndType(2 * 1024, pc, 7 /* mtInternal */ );
+        pb.command(new String[] { JDKToolFinder.getJDKTool("jcmd"), pid, "VM.native_memory", "detail.diff"});
+        output = new OutputAnalyzer(pb.start());
+        output.shouldContain("(malloc=0KB type=Test -4KB)");
+        output.shouldContain("(malloc=2KB type=Internal +2KB #1 +1)");
+        output.shouldHaveExitValue(0);
+  }
+}

--- a/test/lib/sun/hotspot/WhiteBox.java	Fri Feb 08 10:03:07 2019 -0800
+++ b/test/lib/sun/hotspot/WhiteBox.java	Fri Feb 08 14:03:09 2019 -0500
@@ -216,6 +216,7 @@
   public native void NMTUncommitMemory(long addr, long size);
   public native void NMTReleaseMemory(long addr, long size);
   public native long NMTMallocWithPseudoStack(long size, int index);
+  public native long NMTMallocWithPseudoStackAndType(long size, int index, int type);
   public native boolean NMTChangeTrackingLevel();
   public native int NMTGetHashSize();