diff --git a/compiler-rt/lib/scudo/standalone/primary32.h b/compiler-rt/lib/scudo/standalone/primary32.h
--- a/compiler-rt/lib/scudo/standalone/primary32.h
+++ b/compiler-rt/lib/scudo/standalone/primary32.h
@@ -88,7 +88,7 @@
       unmap(reinterpret_cast<void *>(RegionsStash[--NumberOfStashedRegions]),
             RegionSize);
     // TODO(kostyak): unmap the TransferBatch regions as well.
-    for (uptr I = 0; I < NumRegions; I++)
+    for (uptr I = MinRegionIndex; I <= MaxRegionIndex; I++)
       if (PossibleRegions[I])
         unmap(reinterpret_cast<void *>(I * RegionSize), RegionSize);
     PossibleRegions.unmapTestOnly();
@@ -258,14 +258,12 @@
     if (!Region)
       Region = allocateRegionSlow();
     if (LIKELY(Region)) {
-      if (ClassId) {
-        const uptr RegionIndex = computeRegionId(Region);
-        if (RegionIndex < MinRegionIndex)
-          MinRegionIndex = RegionIndex;
-        if (RegionIndex > MaxRegionIndex)
-          MaxRegionIndex = RegionIndex;
-        PossibleRegions.set(RegionIndex, static_cast<u8>(ClassId));
-      }
+      const uptr RegionIndex = computeRegionId(Region);
+      if (RegionIndex < MinRegionIndex)
+        MinRegionIndex = RegionIndex;
+      if (RegionIndex > MaxRegionIndex)
+        MaxRegionIndex = RegionIndex;
+      PossibleRegions.set(RegionIndex, static_cast<u8>(ClassId));
     }
     return Region;
   }
@@ -350,10 +348,10 @@
     const uptr InUse = Sci->Stats.PoppedBlocks - Sci->Stats.PushedBlocks;
     const uptr AvailableChunks = Sci->AllocatedUser / getSizeByClassId(ClassId);
     Str->append("  %02zu (%6zu): mapped: %6zuK popped: %7zu pushed: %7zu "
-                "inuse: %6zu avail: %6zu rss: %6zuK\n",
+                "inuse: %6zu avail: %6zu rss: %6zuK releases: %6zu\n",
                 ClassId, getSizeByClassId(ClassId), Sci->AllocatedUser >> 10,
                 Sci->Stats.PoppedBlocks, Sci->Stats.PushedBlocks, InUse,
-                AvailableChunks, Rss >> 10);
+                AvailableChunks, Rss >> 10, Sci->ReleaseInfo.RangesReleased);
   }
 
   NOINLINE uptr releaseToOSMaybe(SizeClassInfo *Sci, uptr ClassId,
@@ -390,9 +388,10 @@
     uptr TotalReleasedBytes = 0;
     for (uptr I = MinRegionIndex; I <= MaxRegionIndex; I++) {
       if (PossibleRegions[I] == ClassId) {
-        ReleaseRecorder Recorder(I * RegionSize);
-        releaseFreeMemoryToOS(Sci->FreeList, I * RegionSize,
-                              RegionSize / PageSize, BlockSize, &Recorder);
+        const uptr Region = I * RegionSize;
+        ReleaseRecorder Recorder(Region);
+        releaseFreeMemoryToOS(Sci->FreeList, Region, RegionSize / PageSize,
+                              BlockSize, &Recorder);
         if (Recorder.getReleasedRangesCount() > 0) {
           Sci->ReleaseInfo.PushedBlocksAtLastRelease = Sci->Stats.PushedBlocks;
           Sci->ReleaseInfo.RangesReleased += Recorder.getReleasedRangesCount();
diff --git a/compiler-rt/lib/scudo/standalone/size_class_map.h b/compiler-rt/lib/scudo/standalone/size_class_map.h
--- a/compiler-rt/lib/scudo/standalone/size_class_map.h
+++ b/compiler-rt/lib/scudo/standalone/size_class_map.h
@@ -144,7 +144,7 @@
 typedef SizeClassMap<2, 5, 9, 16, 14, 14> AndroidSizeClassMap;
 #else
 typedef SizeClassMap<4, 3, 7, 14, 5, 10> SvelteSizeClassMap;
-typedef SizeClassMap<2, 5, 9, 16, 14, 14> AndroidSizeClassMap;
+typedef SizeClassMap<3, 4, 8, 16, 14, 14> AndroidSizeClassMap;
 #endif
 
 } // namespace scudo
diff --git a/compiler-rt/lib/scudo/standalone/wrappers_c_bionic.cpp b/compiler-rt/lib/scudo/standalone/wrappers_c_bionic.cpp
--- a/compiler-rt/lib/scudo/standalone/wrappers_c_bionic.cpp
+++ b/compiler-rt/lib/scudo/standalone/wrappers_c_bionic.cpp
@@ -55,11 +55,9 @@
 #undef SCUDO_ALLOCATOR
 #undef SCUDO_PREFIX
 
-// The following is the only function that will end up initializing both
-// allocators, which will result in a slight increase in memory footprint.
+// TODO(kostyak): support both allocators.
 INTERFACE void __scudo_print_stats(void) {
   Allocator.printStats();
-  SvelteAllocator.printStats();
 }
 
 #endif // SCUDO_ANDROID && _BIONIC