diff --git a/Tethering/tests/privileged/src/com/android/networkstack/tethering/BpfMapTest.java b/Tethering/tests/privileged/src/com/android/networkstack/tethering/BpfMapTest.java
index a0928c5..47aebe8 100644
--- a/Tethering/tests/privileged/src/com/android/networkstack/tethering/BpfMapTest.java
+++ b/Tethering/tests/privileged/src/com/android/networkstack/tethering/BpfMapTest.java
@@ -112,8 +112,8 @@
 
     private BpfMap<TetherDownstream6Key, Tether6Value> openTestMap() throws Exception {
         return mShouldTestSingleWriterMap
-                ? new SingleWriterBpfMap<>(TETHER2_DOWNSTREAM6_FS_PATH, TetherDownstream6Key.class,
-                Tether6Value.class)
+                ? SingleWriterBpfMap.getSingleton(TETHER2_DOWNSTREAM6_FS_PATH,
+                        TetherDownstream6Key.class, Tether6Value.class)
                 : new BpfMap<>(TETHER_DOWNSTREAM6_FS_PATH, TetherDownstream6Key.class,
                         Tether6Value.class);
     }
@@ -510,12 +510,6 @@
     @Test
     public void testSingleWriterCacheEffectiveness() throws Exception {
         assumeTrue(mShouldTestSingleWriterMap);
-
-        // Ensure the map is not empty.
-        for (int i = 0; i < mTestData.size(); i++) {
-            mTestMap.insertEntry(mTestData.keyAt(i), mTestData.valueAt(i));
-        }
-
         // Benchmark parameters.
         final int timeoutMs = 5_000;  // Only hit if threads don't complete.
         final int benchmarkTimeMs = 2_000;
@@ -524,11 +518,17 @@
         // Only require 3x to reduce test flakiness.
         final int expectedSpeedup = 3;
 
-        final BpfMap cachedMap = new SingleWriterBpfMap(TETHER_DOWNSTREAM6_FS_PATH,
+        final BpfMap cachedMap = SingleWriterBpfMap.getSingleton(TETHER2_DOWNSTREAM6_FS_PATH,
                 TetherDownstream6Key.class, Tether6Value.class);
         final BpfMap uncachedMap = new BpfMap(TETHER_DOWNSTREAM6_FS_PATH,
                 TetherDownstream6Key.class, Tether6Value.class);
 
+        // Ensure the maps are not empty.
+        for (int i = 0; i < mTestData.size(); i++) {
+            cachedMap.insertEntry(mTestData.keyAt(i), mTestData.valueAt(i));
+            uncachedMap.insertEntry(mTestData.keyAt(i), mTestData.valueAt(i));
+        }
+
         final CompletableFuture<Integer> cachedResult = new CompletableFuture<>();
         final CompletableFuture<Integer> uncachedResult = new CompletableFuture<>();
 
diff --git a/service/src/com/android/server/BpfNetMaps.java b/service/src/com/android/server/BpfNetMaps.java
index a30735a..b3e7d8c 100644
--- a/service/src/com/android/server/BpfNetMaps.java
+++ b/service/src/com/android/server/BpfNetMaps.java
@@ -189,7 +189,7 @@
     @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     private static IBpfMap<S32, U32> getConfigurationMap() {
         try {
-            return new SingleWriterBpfMap<>(
+            return SingleWriterBpfMap.getSingleton(
                     CONFIGURATION_MAP_PATH, S32.class, U32.class);
         } catch (ErrnoException e) {
             throw new IllegalStateException("Cannot open netd configuration map", e);
@@ -199,7 +199,7 @@
     @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     private static IBpfMap<S32, UidOwnerValue> getUidOwnerMap() {
         try {
-            return new SingleWriterBpfMap<>(
+            return SingleWriterBpfMap.getSingleton(
                     UID_OWNER_MAP_PATH, S32.class, UidOwnerValue.class);
         } catch (ErrnoException e) {
             throw new IllegalStateException("Cannot open uid owner map", e);
@@ -209,7 +209,7 @@
     @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     private static IBpfMap<S32, U8> getUidPermissionMap() {
         try {
-            return new SingleWriterBpfMap<>(
+            return SingleWriterBpfMap.getSingleton(
                     UID_PERMISSION_MAP_PATH, S32.class, U8.class);
         } catch (ErrnoException e) {
             throw new IllegalStateException("Cannot open uid permission map", e);
@@ -230,7 +230,7 @@
     @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     private static IBpfMap<S32, U8> getDataSaverEnabledMap() {
         try {
-            return new SingleWriterBpfMap<>(
+            return SingleWriterBpfMap.getSingleton(
                     DATA_SAVER_ENABLED_MAP_PATH, S32.class, U8.class);
         } catch (ErrnoException e) {
             throw new IllegalStateException("Cannot open data saver enabled map", e);
@@ -240,7 +240,7 @@
     @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     private static IBpfMap<IngressDiscardKey, IngressDiscardValue> getIngressDiscardMap() {
         try {
-            return new SingleWriterBpfMap<>(INGRESS_DISCARD_MAP_PATH,
+            return SingleWriterBpfMap.getSingleton(INGRESS_DISCARD_MAP_PATH,
                     IngressDiscardKey.class, IngressDiscardValue.class);
         } catch (ErrnoException e) {
             throw new IllegalStateException("Cannot open ingress discard map", e);
diff --git a/staticlibs/device/com/android/net/module/util/SingleWriterBpfMap.java b/staticlibs/device/com/android/net/module/util/SingleWriterBpfMap.java
index bbd921d..cd6bfec 100644
--- a/staticlibs/device/com/android/net/module/util/SingleWriterBpfMap.java
+++ b/staticlibs/device/com/android/net/module/util/SingleWriterBpfMap.java
@@ -17,6 +17,7 @@
 
 import android.os.Build;
 import android.system.ErrnoException;
+import android.util.Pair;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.RequiresApi;
@@ -61,7 +62,12 @@
     // our code can contain hundreds of items.
     private final HashMap<K, V> mCache = new HashMap<>();
 
-    public SingleWriterBpfMap(@NonNull final String path, final Class<K> key,
+    // This should only ever be called (hence private) once for a given 'path'.
+    // Java-wise what matters is the entire {path, key, value} triplet,
+    // but of course the kernel exclusive lock is just on the path (fd),
+    // and any BpfMap has (or should have...) well defined key/value types
+    // (or at least their sizes) so in practice it doesn't really matter.
+    private SingleWriterBpfMap(@NonNull final String path, final Class<K> key,
             final Class<V> value) throws ErrnoException, NullPointerException {
         super(path, BPF_F_RDWR_EXCLUSIVE, key, value);
 
@@ -73,6 +79,24 @@
         }
     }
 
+    // This allows reuse of SingleWriterBpfMap objects for the same {path, keyClass, valueClass}.
+    // These are never destroyed, so once created the lock is (effectively) held till process death
+    // (even if fixed, there would still be a write-only fd cache in underlying BpfMap base class).
+    private static final HashMap<Pair<String, Pair<Class, Class>>, SingleWriterBpfMap>
+            singletonCache = new HashMap<>();
+
+    // This is the public 'factory method' that (creates if needed and) returns a singleton instance
+    // for a given map.  This holds an exclusive lock and has a permanent write-through cache.
+    // It will not be released until process death (or at least unload of the relevant class loader)
+    public synchronized static <KK extends Struct, VV extends Struct> SingleWriterBpfMap<KK,VV>
+            getSingleton(@NonNull final String path, final Class<KK> key, final Class<VV> value)
+            throws ErrnoException, NullPointerException {
+        var cacheKey = new Pair<>(path, new Pair<Class,Class>(key, value));
+        if (!singletonCache.containsKey(cacheKey))
+            singletonCache.put(cacheKey, new SingleWriterBpfMap(path, key, value));
+        return singletonCache.get(cacheKey);
+    }
+
     @Override
     public synchronized void updateEntry(K key, V value) throws ErrnoException {
         super.updateEntry(key, value);