diff --git a/hadoop-common-project/hadoop-common/CHANGES.txt b/hadoop-common-project/hadoop-common/CHANGES.txt
index aa296fe1c87..e9fdc92b87f 100644
--- a/hadoop-common-project/hadoop-common/CHANGES.txt
+++ b/hadoop-common-project/hadoop-common/CHANGES.txt
@@ -10,6 +10,8 @@ Release 2.6.0 - UNRELEASED
 
     HADOOP-10808. Remove unused native code for munlock. (cnauroth)
 
+    HADOOP-10815. Implement Windows equivalent of mlock. (cnauroth)
+
   OPTIMIZATIONS
 
   BUG FIXES
diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/nativeio/NativeIO.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/nativeio/NativeIO.java
index 423383e4d1a..976a93f91b1 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/nativeio/NativeIO.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/nativeio/NativeIO.java
@@ -551,6 +551,19 @@ public static boolean access(String path, AccessRight desiredAccess)
       return access0(path, desiredAccess.accessRight());
     }
 
+    /**
+     * Extends both the minimum and maximum working set size of the current
+     * process.  This method gets the current minimum and maximum working set
+     * size, adds the requested amount to each and then sets the minimum and
+     * maximum working set size to the new values.  Controlling the working set
+     * size of the process also controls the amount of memory it can lock.
+     *
+     * @param delta amount to increment minimum and maximum working set size
+     * @throws IOException for any error
+     * @see POSIX#mlock(ByteBuffer, long)
+     */
+    public static native void extendWorkingSetSize(long delta) throws IOException;
+
     static {
       if (NativeCodeLoader.isNativeCodeLoaded()) {
         try {
diff --git a/hadoop-common-project/hadoop-common/src/main/native/src/org/apache/hadoop/io/nativeio/NativeIO.c b/hadoop-common-project/hadoop-common/src/main/native/src/org/apache/hadoop/io/nativeio/NativeIO.c
index b19d88c334c..e3ad3272423 100644
--- a/hadoop-common-project/hadoop-common/src/main/native/src/org/apache/hadoop/io/nativeio/NativeIO.c
+++ b/hadoop-common-project/hadoop-common/src/main/native/src/org/apache/hadoop/io/nativeio/NativeIO.c
@@ -388,10 +388,10 @@ Java_org_apache_hadoop_io_nativeio_NativeIO_00024POSIX_mlock_1native(
   JNIEnv *env, jclass clazz,
   jobject buffer, jlong len)
 {
-#ifdef UNIX
   void* buf = (void*)(*env)->GetDirectBufferAddress(env, buffer);
   PASS_EXCEPTIONS(env);
 
+#ifdef UNIX
   if (mlock(buf, len)) {
     CHECK_DIRECT_BUFFER_ADDRESS(buf);
     throw_ioe(env, errno);
@@ -399,8 +399,10 @@ Java_org_apache_hadoop_io_nativeio_NativeIO_00024POSIX_mlock_1native(
 #endif
 
 #ifdef WINDOWS
-  THROW(env, "java/io/IOException",
-    "The function POSIX.mlock_native() is not supported on Windows");
+  if (!VirtualLock(buf, len)) {
+    CHECK_DIRECT_BUFFER_ADDRESS(buf);
+    throw_ioe(env, GetLastError());
+  }
 #endif
 }
 
@@ -980,6 +982,40 @@ cleanup:
 #endif
 }
 
+/*
+ * Class:     org_apache_hadoop_io_nativeio_NativeIO_Windows
+ * Method:    extendWorkingSetSize
+ * Signature: (J)V
+ *
+ * The "00024" in the function name is an artifact of how JNI encodes
+ * special characters. U+0024 is '$'.
+ */
+JNIEXPORT void JNICALL
+Java_org_apache_hadoop_io_nativeio_NativeIO_00024Windows_extendWorkingSetSize(
+  JNIEnv *env, jclass clazz, jlong delta)
+{
+#ifdef UNIX
+  THROW(env, "java/io/IOException",
+    "The function extendWorkingSetSize(delta) is not supported on Unix");
+#endif
+
+#ifdef WINDOWS
+  SIZE_T min, max;
+  HANDLE hProcess = GetCurrentProcess();
+  if (!GetProcessWorkingSetSize(hProcess, &min, &max)) {
+    throw_ioe(env, GetLastError());
+    return;
+  }
+  if (!SetProcessWorkingSetSizeEx(hProcess, min + delta, max + delta,
+      QUOTA_LIMITS_HARDWS_MIN_DISABLE | QUOTA_LIMITS_HARDWS_MAX_DISABLE)) {
+    throw_ioe(env, GetLastError());
+    return;
+  }
+  // There is no need to call CloseHandle on the pseudo-handle returned from
+  // GetCurrentProcess.
+#endif
+}
+
 JNIEXPORT void JNICALL 
 Java_org_apache_hadoop_io_nativeio_NativeIO_renameTo0(JNIEnv *env, 
 jclass clazz, jstring jsrc, jstring jdst)
diff --git a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/nativeio/TestNativeIO.java b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/nativeio/TestNativeIO.java
index dc02409ed44..6c3f0038863 100644
--- a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/nativeio/TestNativeIO.java
+++ b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/nativeio/TestNativeIO.java
@@ -49,7 +49,6 @@
 import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.util.NativeCodeLoader;
-import org.apache.hadoop.util.Shell;
 import org.apache.hadoop.util.Time;
 
 public class TestNativeIO {
@@ -572,7 +571,6 @@ public void testRenameTo() throws Exception {
   @Test(timeout=10000)
   public void testMlock() throws Exception {
     assumeTrue(NativeIO.isAvailable());
-    assumeTrue(Shell.LINUX);
     final File TEST_FILE = new File(new File(
         System.getProperty("test.build.data","build/test/data")),
         "testMlockFile");