2 files changed, 25 insertions, 10 deletions

diff --git a/src/pkg/runtime/malloc.goc b/src/pkg/runtime/malloc.goc
index 44b68a728d..2dff981fb4 100644
--- a/src/pkg/runtime/malloc.goc
+++ b/src/pkg/runtime/malloc.goc
@@ -72,6 +72,14 @@ runtime·mallocgc(uintptr size, uint32 flag, int32 dogc, int32 zeroed)
 		// setup for mark sweep
 		runtime·markspan(v, 0, 0, true);
 	}
+
+	if (sizeof(void*) == 4 && c->local_total_alloc >= (1<<30)) {
+		// purge cache stats to prevent overflow
+		runtime·lock(&runtime·mheap);
+		runtime·purgecachedstats(m);
+		runtime·unlock(&runtime·mheap);
+	}
+
 	if(!(flag & FlagNoGC))
 		runtime·markallocated(v, size, (flag&FlagNoPointers) != 0);
 
@@ -170,6 +178,13 @@ runtime·mlookup(void *v, byte **base, uintptr *size, MSpan **sp)
 	MSpan *s;
 
 	m->mcache->local_nlookup++;
+	if (sizeof(void*) == 4 && m->mcache->local_nlookup >= (1<<30)) {
+		// purge cache stats to prevent overflow
+		runtime·lock(&runtime·mheap);
+		runtime·purgecachedstats(m);
+		runtime·unlock(&runtime·mheap);
+	}
+
 	s = runtime·MHeap_LookupMaybe(&runtime·mheap, v);
 	if(sp)
 		*sp = s;
diff --git a/src/pkg/runtime/malloc.h b/src/pkg/runtime/malloc.h
index 065f86a42a..f2408f18f2 100644
--- a/src/pkg/runtime/malloc.h
+++ b/src/pkg/runtime/malloc.h
@@ -273,19 +273,19 @@ struct MCacheList
 struct MCache
 {
 	MCacheList list[NumSizeClasses];
-	uint64 size;
-	int64 local_cachealloc;	// bytes allocated (or freed) from cache since last lock of heap
-	int64 local_objects;	// objects allocated (or freed) from cache since last lock of heap
-	int64 local_alloc;	// bytes allocated (or freed) since last lock of heap
-	int64 local_total_alloc;	// bytes allocated (even if freed) since last lock of heap
-	int64 local_nmalloc;	// number of mallocs since last lock of heap
-	int64 local_nfree;	// number of frees since last lock of heap
-	int64 local_nlookup;	// number of pointer lookups since last lock of heap
+	uintptr size;
+	intptr local_cachealloc;	// bytes allocated (or freed) from cache since last lock of heap
+	intptr local_objects;	// objects allocated (or freed) from cache since last lock of heap
+	intptr local_alloc;	// bytes allocated (or freed) since last lock of heap
+	uintptr local_total_alloc;	// bytes allocated (even if freed) since last lock of heap
+	uintptr local_nmalloc;	// number of mallocs since last lock of heap
+	uintptr local_nfree;	// number of frees since last lock of heap
+	uintptr local_nlookup;	// number of pointer lookups since last lock of heap
 	int32 next_sample;	// trigger heap sample after allocating this many bytes
 	// Statistics about allocation size classes since last lock of heap
 	struct {
-		int64 nmalloc;
-		int64 nfree;
+		uintptr nmalloc;
+		uintptr nfree;
 	} local_by_size[NumSizeClasses];
 
 };