code review 5279048: runtime: faster and more scalable GC

src/pkg/runtime/malloc.h

Index: src/pkg/runtime/malloc.h
===================================================================
--- a/src/pkg/runtime/malloc.h
+++ b/src/pkg/runtime/malloc.h
@@ -306,7 +306,6 @@
 {
 	MSpan	*next;		// in a span linked list
 	MSpan	*prev;		// in a span linked list
-	MSpan	*allnext;	// in the list of all spans
 	PageID	start;		// starting page number
 	uintptr	npages;		// number of pages in span
 	MLink	*freelist;	// list of free objects
@@ -342,6 +341,7 @@
 void	runtime·MCentral_Init(MCentral *c, int32 sizeclass);
 int32	runtime·MCentral_AllocList(MCentral *c, int32 n, MLink **first);
 void	runtime·MCentral_FreeList(MCentral *c, int32 n, MLink *first);
+void	runtime·MCentral_FreeSpan(MCentral *c, MSpan *s, int32 n, MLink *start, MLink *end);
 
 // Main malloc heap.
 // The heap itself is the "free[]" and "large" arrays,
@@ -351,7 +351,9 @@
 	Lock;
 	MSpan free[MaxMHeapList];	// free lists of given length
 	MSpan large;			// free lists length >= MaxMHeapList
-	MSpan *allspans;
+	MSpan	**allspans;
+	uintptr	nspan;
+	uintptr	nspancap;
 
 	// span lookup
 	MSpan *map[1<<MHeapMap_Bits];
@@ -412,7 +414,11 @@
 void	runtime·MProf_Malloc(void*, uintptr);
 void	runtime·MProf_Free(void*, uintptr);
 void	runtime·MProf_GC(void);
-int32	runtime·helpgc(bool*);
+
+void	runtime·stoptheworld(void);
+void	runtime·starttheworld(void);
+int32	runtime·gcprocs(void);
+void	runtime·helpgc(int32 nproc);
 void	runtime·gchelper(void);
 
 bool	runtime·getfinalizer(void *p, bool del, void (**fn)(void*), int32 *nret);