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
@@ -395,14 +395,6 @@
   // Use `SameGroup=true` to indicate that all blocks in the array are from the
   // same group then we will skip checking the group id of each block.
   //
-  // Note that this aims to have a better management of dirty pages, i.e., the
-  // RSS usage won't grow indefinitely. There's an exception that we may not put
-  // a block to its associated group. While populating new blocks, we may have
-  // blocks cross different groups. However, most cases will fall into same
-  // group and they are supposed to be popped soon. In that case, it's not worth
-  // sorting the array with the almost-sorted property. Therefore, we use
-  // `SameGroup=true` instead.
-  //
   // The region mutex needs to be held while calling this method.
   void pushBlocksImpl(CacheT *C, uptr ClassId, SizeClassInfo *Sci,
                       CompactPtrT *Array, u32 Size, bool SameGroup = false)
@@ -537,6 +529,9 @@
     // All the blocks are from the same group, just push without checking group
     // id.
     if (SameGroup) {
+      for (u32 I = 0; I < Size; ++I)
+        DCHECK_EQ(compactPtrGroup(Array[I]), Cur->GroupId);
+
       InsertBlocks(Cur, Array, Size);
       return;
     }
@@ -648,11 +643,29 @@
     uptr P = Region + Offset;
     for (u32 I = 0; I < NumberOfBlocks; I++, P += Size)
       ShuffleArray[I] = reinterpret_cast<CompactPtrT>(P);
-    // No need to shuffle the batches size class.
-    if (ClassId != SizeClassMap::BatchClassId)
-      shuffle(ShuffleArray, NumberOfBlocks, &Sci->RandState);
-    pushBlocksImpl(C, ClassId, Sci, ShuffleArray, NumberOfBlocks,
-                   /*SameGroup=*/true);
+
+    if (ClassId != SizeClassMap::BatchClassId) {
+      u32 N = 1;
+      uptr CurGroup = compactPtrGroup(ShuffleArray[0]);
+      for (u32 I = 1; I < NumberOfBlocks; I++) {
+        if (UNLIKELY(compactPtrGroup(ShuffleArray[I]) != CurGroup)) {
+          shuffle(ShuffleArray + I - N, N, &Sci->RandState);
+          pushBlocksImpl(C, ClassId, Sci, ShuffleArray + I - N, N,
+                         /*SameGroup=*/true);
+          N = 1;
+          CurGroup = compactPtrGroup(ShuffleArray[I]);
+        } else {
+          ++N;
+        }
+      }
+
+      shuffle(ShuffleArray + NumberOfBlocks - N, N, &Sci->RandState);
+      pushBlocksImpl(C, ClassId, Sci, &ShuffleArray[NumberOfBlocks - N], N,
+                     /*SameGroup=*/true);
+    } else {
+      pushBlocksImpl(C, ClassId, Sci, ShuffleArray, NumberOfBlocks,
+                     /*SameGroup=*/true);
+    }
 
     const uptr AllocatedUser = Size * NumberOfBlocks;
     C->getStats().add(StatFree, AllocatedUser);
diff --git a/compiler-rt/lib/scudo/standalone/primary64.h b/compiler-rt/lib/scudo/standalone/primary64.h
--- a/compiler-rt/lib/scudo/standalone/primary64.h
+++ b/compiler-rt/lib/scudo/standalone/primary64.h
@@ -458,14 +458,6 @@
   // Use `SameGroup=true` to indicate that all blocks in the array are from the
   // same group then we will skip checking the group id of each block.
   //
-  // Note that this aims to have a better management of dirty pages, i.e., the
-  // RSS usage won't grow indefinitely. There's an exception that we may not put
-  // a block to its associated group. While populating new blocks, we may have
-  // blocks cross different groups. However, most cases will fall into same
-  // group and they are supposed to be popped soon. In that case, it's not worth
-  // sorting the array with the almost-sorted property. Therefore, we use
-  // `SameGroup=true` instead.
-  //
   // The region mutex needs to be held while calling this method.
   void pushBlocksImpl(CacheT *C, uptr ClassId, RegionInfo *Region,
                       CompactPtrT *Array, u32 Size, bool SameGroup = false)
@@ -600,6 +592,9 @@
     // All the blocks are from the same group, just push without checking group
     // id.
     if (SameGroup) {
+      for (u32 I = 0; I < Size; ++I)
+        DCHECK_EQ(compactPtrGroup(Array[I]), Cur->GroupId);
+
       InsertBlocks(Cur, Array, Size);
       return;
     }
@@ -712,11 +707,29 @@
     uptr P = RegionBeg + Region->AllocatedUser;
     for (u32 I = 0; I < NumberOfBlocks; I++, P += Size)
       ShuffleArray[I] = compactPtrInternal(CompactPtrBase, P);
-    // No need to shuffle the batches size class.
-    if (ClassId != SizeClassMap::BatchClassId)
-      shuffle(ShuffleArray, NumberOfBlocks, &Region->RandState);
-    pushBlocksImpl(C, ClassId, Region, ShuffleArray, NumberOfBlocks,
-                   /*SameGroup=*/true);
+
+    if (ClassId != SizeClassMap::BatchClassId) {
+      u32 N = 1;
+      uptr CurGroup = compactPtrGroup(ShuffleArray[0]);
+      for (u32 I = 1; I < NumberOfBlocks; I++) {
+        if (UNLIKELY(compactPtrGroup(ShuffleArray[I]) != CurGroup)) {
+          shuffle(ShuffleArray + I - N, N, &Region->RandState);
+          pushBlocksImpl(C, ClassId, Region, ShuffleArray + I - N, N,
+                         /*SameGroup=*/true);
+          N = 1;
+          CurGroup = compactPtrGroup(ShuffleArray[I]);
+        } else {
+          ++N;
+        }
+      }
+
+      shuffle(ShuffleArray + NumberOfBlocks - N, N, &Region->RandState);
+      pushBlocksImpl(C, ClassId, Region, &ShuffleArray[NumberOfBlocks - N], N,
+                     /*SameGroup=*/true);
+    } else {
+      pushBlocksImpl(C, ClassId, Region, ShuffleArray, NumberOfBlocks,
+                     /*SameGroup=*/true);
+    }
 
     const uptr AllocatedUser = Size * NumberOfBlocks;
     C->getStats().add(StatFree, AllocatedUser);