diff --git a/compiler-rt/lib/scudo/standalone/common.h b/compiler-rt/lib/scudo/standalone/common.h
--- a/compiler-rt/lib/scudo/standalone/common.h
+++ b/compiler-rt/lib/scudo/standalone/common.h
@@ -149,6 +149,7 @@
 #define MAP_NOACCESS (1U << 1)
 #define MAP_RESIZABLE (1U << 2)
 #define MAP_MEMTAG (1U << 3)
+#define MAP_PRECOMMIT (1U << 4)
 
 // Our platform memory mapping use is restricted to 3 scenarios:
 // - reserve memory at a random address (MAP_NOACCESS);
diff --git a/compiler-rt/lib/scudo/standalone/fuchsia.cpp b/compiler-rt/lib/scudo/standalone/fuchsia.cpp
--- a/compiler-rt/lib/scudo/standalone/fuchsia.cpp
+++ b/compiler-rt/lib/scudo/standalone/fuchsia.cpp
@@ -97,6 +97,17 @@
   if (Offset)
     MapFlags |= ZX_VM_SPECIFIC;
   Status = _zx_vmar_map(Vmar, MapFlags, Offset, Vmo, VmoSize, Size, &P);
+  if (UNLIKELY(Status != ZX_OK)) {
+    if (Status != ZX_ERR_NO_MEMORY || !AllowNoMem)
+      dieOnMapUnmapError(Status == ZX_ERR_NO_MEMORY ? Size : 0);
+    return nullptr;
+  }
+
+  if (Flags & MAP_PRECOMMIT) {
+    Status = _zx_vmar_op_range(Vmar, ZX_VMAR_OP_COMMIT, P, Size,
+                               /*buffer=*/nullptr, /*buffer_size=*/0);
+  }
+
   // No need to track the Vmo if we don't intend on resizing it. Close it.
   if (Flags & MAP_RESIZABLE) {
     DCHECK(Data);
@@ -112,6 +123,7 @@
       dieOnMapUnmapError(Status == ZX_ERR_NO_MEMORY ? Size : 0);
     return nullptr;
   }
+
   if (Data)
     Data->VmoSize += Size;
 
diff --git a/compiler-rt/lib/scudo/standalone/release.h b/compiler-rt/lib/scudo/standalone/release.h
--- a/compiler-rt/lib/scudo/standalone/release.h
+++ b/compiler-rt/lib/scudo/standalone/release.h
@@ -107,9 +107,15 @@
       Buffer = &StaticBuffer[0];
       memset(Buffer, 0, BufferSize);
     } else {
+      // When using a heap-based buffer, precommit the pages backing the
+      // Vmar by passing |MAP_PRECOMMIT| flag. This allows an optimization
+      // where page fault exceptions are skipped as the allocated memory
+      // is accessed.
+      const uptr MmapFlags =
+          MAP_ALLOWNOMEM | (SCUDO_FUCHSIA ? MAP_PRECOMMIT : 0);
       Buffer = reinterpret_cast<uptr *>(
           map(nullptr, roundUpTo(BufferSize, getPageSizeCached()),
-              "scudo:counters", MAP_ALLOWNOMEM, &MapData));
+              "scudo:counters", MmapFlags, &MapData));
     }
   }