runtime: clock garbage collection on bytes allocated, not pages in use

This keeps fragmentation from delaying
garbage collections (and causing more fragmentation).

Cuts fresh godoc (with indexes) from 261M to 166M (120M live).
Cuts toy wc program from 50M to 8M.

Fixes issue 647.

R=r, cw
CC=golang-dev
http://codereview.appspot.com/257041

1 files changed, 7 insertions, 5 deletions

diff --git a/src/pkg/runtime/malloc.h b/src/pkg/runtime/malloc.h
index b9dea2f5e..ae6b70b14 100644
--- a/src/pkg/runtime/malloc.h
+++ b/src/pkg/runtime/malloc.h
@@ -168,12 +168,13 @@ void	FixAlloc_Free(FixAlloc *f, void *p);
 // Shared with Go: if you edit this structure, also edit extern.go.
 struct MStats
 {
-	uint64	alloc;
-	uint64	total_alloc;
+	uint64	alloc;	// unprotected (approximate)
+	uint64	total_alloc;	// unprotected (approximate)
 	uint64	sys;
 	uint64	stacks;
 	uint64	inuse_pages;	// protected by mheap.Lock
 	uint64	next_gc;	// protected by mheap.Lock
+	uint64	heap_alloc;	// protected by mheap.Lock
 	uint64	nlookup;	// unprotected (approximate)
 	uint64	nmalloc;	// unprotected (approximate)
 	uint64	pause_ns;
@@ -225,11 +226,12 @@ struct MCache
 {
 	MCacheList list[NumSizeClasses];
 	uint64 size;
+	int64 local_alloc;	// bytes allocated (or freed) since last lock of heap
 };
 
 void*	MCache_Alloc(MCache *c, int32 sizeclass, uintptr size, int32 zeroed);
 void	MCache_Free(MCache *c, void *p, int32 sizeclass, uintptr size);
-
+void	MCache_ReleaseAll(MCache *c);
 
 // An MSpan is a run of pages.
 enum
@@ -313,8 +315,8 @@ struct MHeap
 extern MHeap mheap;
 
 void	MHeap_Init(MHeap *h, void *(*allocator)(uintptr));
-MSpan*	MHeap_Alloc(MHeap *h, uintptr npage, int32 sizeclass);
-void	MHeap_Free(MHeap *h, MSpan *s);
+MSpan*	MHeap_Alloc(MHeap *h, uintptr npage, int32 sizeclass, int32 acct);
+void	MHeap_Free(MHeap *h, MSpan *s, int32 acct);
 MSpan*	MHeap_Lookup(MHeap *h, PageID p);
 MSpan*	MHeap_LookupMaybe(MHeap *h, PageID p);
 void	MGetSizeClassInfo(int32 sizeclass, int32 *size, int32 *npages, int32 *nobj);