diff --git a/src/pkg/runtime/extern.go b/src/pkg/runtime/extern.go
index bcef7244aa2..6d98e50db42 100644
--- a/src/pkg/runtime/extern.go
+++ b/src/pkg/runtime/extern.go
@@ -157,6 +157,8 @@ type MemStatsType struct {
 	MSpanSys    uint64
 	MCacheInuse uint64 // mcache structures
 	MCacheSys   uint64
+	MHeapMapSys uint64 // heap map
+	BuckHashSys uint64 // profiling bucket hash table
 
 	// Garbage collector statistics.
 	NextGC   uint64
diff --git a/src/pkg/runtime/malloc.h b/src/pkg/runtime/malloc.h
index ff869cacbd5..caed4d3fc4e 100644
--- a/src/pkg/runtime/malloc.h
+++ b/src/pkg/runtime/malloc.h
@@ -192,6 +192,8 @@ struct MStats
 	uint64	mspan_sys;
 	uint64	mcache_inuse;	// MCache structures
 	uint64	mcache_sys;
+	uint64	heapmap_sys;	// heap map
+	uint64	buckhash_sys;	// profiling bucket hash table
 	
 	// Statistics about garbage collector.
 	// Protected by stopping the world during GC.
diff --git a/src/pkg/runtime/mheap.c b/src/pkg/runtime/mheap.c
index 1b47b3fe275..44817ddd5ab 100644
--- a/src/pkg/runtime/mheap.c
+++ b/src/pkg/runtime/mheap.c
@@ -176,6 +176,7 @@ MHeap_Grow(MHeap *h, uintptr npage)
 		if(v == nil)
 			return false;
 	}
+	mstats.heap_sys += ask;
 
 	if((byte*)v < h->min || h->min == nil)
 		h->min = v;
diff --git a/src/pkg/runtime/mheapmap32.c b/src/pkg/runtime/mheapmap32.c
index 1e3598cbea0..4481e11f653 100644
--- a/src/pkg/runtime/mheapmap32.c
+++ b/src/pkg/runtime/mheapmap32.c
@@ -84,6 +84,7 @@ MHeapMap_Preallocate(MHeapMap *m, PageID k, uintptr len)
 			p2 = m->allocator(sizeof *p2);
 			if(p2 == nil)
 				return false;
+			mstats.heapmap_sys += sizeof *p2;
 			m->p[i1] = p2;
 		}
 
diff --git a/src/pkg/runtime/mheapmap64.c b/src/pkg/runtime/mheapmap64.c
index 2f856ee179f..d5590a2d843 100644
--- a/src/pkg/runtime/mheapmap64.c
+++ b/src/pkg/runtime/mheapmap64.c
@@ -96,6 +96,7 @@ MHeapMap_Preallocate(MHeapMap *m, PageID k, uintptr len)
 			p2 = m->allocator(sizeof *p2);
 			if(p2 == nil)
 				return false;
+			mstats.heapmap_sys += sizeof *p2;
 			m->p[i1] = p2;
 		}
 
@@ -104,6 +105,7 @@ MHeapMap_Preallocate(MHeapMap *m, PageID k, uintptr len)
 			p3 = m->allocator(sizeof *p3);
 			if(p3 == nil)
 				return false;
+			mstats.heapmap_sys += sizeof *p3;
 			p2->p[i2] = p3;
 		}
 
diff --git a/src/pkg/runtime/mprof.cgo b/src/pkg/runtime/mprof.cgo
index 50bcaec3c33..0cddb243d29 100644
--- a/src/pkg/runtime/mprof.cgo
+++ b/src/pkg/runtime/mprof.cgo
@@ -44,8 +44,10 @@ stkbucket(uintptr *stk, int32 nstk)
 	uintptr h;
 	Bucket *b;
 
-	if(buckhash == nil)
+	if(buckhash == nil) {
 		buckhash = SysAlloc(BuckHashSize*sizeof buckhash[0]);
+		mstats.buckhash_sys += BuckHashSize*sizeof buckhash[0];
+	}
 
 	// Hash stack.
 	h = 0;
diff --git a/src/pkg/runtime/pprof/pprof.go b/src/pkg/runtime/pprof/pprof.go
index 3a60551283f..d0cc730899d 100644
--- a/src/pkg/runtime/pprof/pprof.go
+++ b/src/pkg/runtime/pprof/pprof.go
@@ -88,6 +88,8 @@ func WriteHeapProfile(w io.Writer) os.Error {
 	fmt.Fprintf(b, "# Stack = %d / %d\n", s.StackInuse, s.StackSys)
 	fmt.Fprintf(b, "# MSpan = %d / %d\n", s.MSpanInuse, s.MSpanSys)
 	fmt.Fprintf(b, "# MCache = %d / %d\n", s.MCacheInuse, s.MCacheSys)
+	fmt.Fprintf(b, "# MHeapMapSys = %d\n", s.MHeapMapSys)
+	fmt.Fprintf(b, "# BuckHashSys = %d\n", s.BuckHashSys)
 
 	fmt.Fprintf(b, "# NextGC = %d\n", s.NextGC)
 	fmt.Fprintf(b, "# PauseNs = %d\n", s.PauseNs)
@@ -96,6 +98,7 @@ func WriteHeapProfile(w io.Writer) os.Error {
 	fmt.Fprintf(b, "# DebugGC = %v\n", s.DebugGC)
 
 	fmt.Fprintf(b, "# BySize = Size * (Active = Mallocs - Frees)\n")
+	fmt.Fprintf(b, "# (Excluding large blocks.)\n")
 	for _, t := range s.BySize {
 		if t.Mallocs > 0 {
 			fmt.Fprintf(b, "#   %d * (%d = %d - %d)\n", t.Size, t.Mallocs-t.Frees, t.Mallocs, t.Frees)