diff --git a/libguile/ChangeLog b/libguile/ChangeLog
index 13e0836a3..a06959750 100644
--- a/libguile/ChangeLog
+++ b/libguile/ChangeLog
@@ -1,3 +1,15 @@
+2007-01-23  Han-Wen Nienhuys  <hanwen@lilypond.org>
+
+	* gc.c (s_scm_gc_stats): return total cells allocated in a run as
+	'total-cells-allocated in gc-stats output. This allows profiling
+	of a program's memory use.
+
+	* gc-segment.c (scm_i_sweep_some_cards): update
+	scm_gc_cells_allocated_acc when sweeping happens.
+
+	* gc.h: add scm_gc_cells_allocated_acc, scm_last_cells_allocated.
+	
+
 2007-01-19  Ludovic Courtès  <ludovic.courtes@laas.fr>
 
 	* struct.c (scm_i_struct_equalp): Skip comparison if both FIELD1
diff --git a/libguile/gc-segment.c b/libguile/gc-segment.c
index db1c800f5..3bca00b8d 100644
--- a/libguile/gc-segment.c
+++ b/libguile/gc-segment.c
@@ -170,8 +170,13 @@ scm_i_sweep_some_cards (scm_t_heap_segment *seg)
   scm_gc_cells_collected += collected * seg->span;
 
   if (!seg->first_time)
-    scm_cells_allocated -= collected * seg->span;
-  
+    {
+      scm_gc_cells_allocated_acc +=
+	(scm_cells_allocated - scm_last_cells_allocated);
+
+      scm_cells_allocated -= collected * seg->span;
+      scm_last_cells_allocated = scm_cells_allocated;
+    }
   seg->freelist->collected += collected  * seg->span;
   
 
@@ -202,14 +207,24 @@ scm_i_sweep_segment (scm_t_heap_segment * seg)
   int yield = scm_gc_cells_collected;
   int coll = seg->freelist->collected;
   unsigned long alloc = scm_cells_allocated ;
+  unsigned long last_alloc = scm_last_cells_allocated;
+  double last_total
+    = scm_gc_cells_allocated_acc
+    + (alloc - last_alloc);
   
   while (scm_i_sweep_some_cards (seg) != SCM_EOL)
     ;
-
-  scm_gc_cells_collected = yield;
-  scm_cells_allocated = alloc;
-  seg->freelist->collected = coll; 
   
+  scm_gc_cells_collected = yield;
+
+  /*
+   * restore old stats. 
+   */
+  scm_gc_cells_allocated_acc = last_total;
+  scm_cells_allocated = alloc;
+  scm_last_cells_allocated = alloc;
+
+  seg->freelist->collected = coll; 
   seg->next_free_card =p;
 }
 
diff --git a/libguile/gc.c b/libguile/gc.c
index 364dd39f2..f045bcc90 100644
--- a/libguile/gc.c
+++ b/libguile/gc.c
@@ -213,6 +213,7 @@ unsigned long scm_mtrigger;
 /* GC Statistics Keeping
  */
 unsigned long scm_cells_allocated = 0;
+unsigned long scm_last_cells_allocated;
 unsigned long scm_mallocated = 0;
 unsigned long scm_gc_cells_collected;
 unsigned long scm_gc_cells_collected_1 = 0; /* previous GC yield */
@@ -225,6 +226,7 @@ unsigned long scm_gc_times = 0;
 unsigned long scm_gc_cells_swept = 0;
 double scm_gc_cells_marked_acc = 0.;
 double scm_gc_cells_swept_acc = 0.;
+double scm_gc_cells_allocated_acc = 0.;
 int scm_gc_cell_yield_percentage =0;
 int scm_gc_malloc_yield_percentage = 0;
 unsigned long protected_obj_count = 0;
@@ -243,6 +245,7 @@ SCM_SYMBOL (sym_cells_swept, "cells-swept");
 SCM_SYMBOL (sym_malloc_yield, "malloc-yield");
 SCM_SYMBOL (sym_cell_yield, "cell-yield");
 SCM_SYMBOL (sym_protected_objects, "protected-objects");
+SCM_SYMBOL (sym_total_cells_allocated, "total-cells-allocated");
 
 
 
@@ -315,6 +318,7 @@ SCM_DEFINE (scm_gc_stats, "gc-stats", 0, 0, 0,
   unsigned long int local_protected_obj_count;
   double local_scm_gc_cells_swept;
   double local_scm_gc_cells_marked;
+  double local_scm_total_cells_allocated;
   SCM answer;
   unsigned long *bounds = 0;
   int table_size = scm_i_heap_segment_table_size;  
@@ -356,6 +360,9 @@ SCM_DEFINE (scm_gc_stats, "gc-stats", 0, 0, 0,
     +(double) scm_gc_cells_swept 
     -(double) scm_gc_cells_collected;
 
+  local_scm_total_cells_allocated = scm_gc_cells_allocated_acc
+    + (double) (scm_cells_allocated - scm_last_cells_allocated);
+
   for (i = table_size; i--;)
     {
       heap_segs = scm_cons (scm_cons (scm_from_ulong (bounds[2*i]),
@@ -369,6 +376,8 @@ SCM_DEFINE (scm_gc_stats, "gc-stats", 0, 0, 0,
 			  scm_from_ulong (local_scm_gc_time_taken)),
 		scm_cons (sym_cells_allocated,
 			  scm_from_ulong (local_scm_cells_allocated)),
+		scm_cons (sym_total_cells_allocated,
+			  scm_from_ulong (local_scm_total_cells_allocated)),
 		scm_cons (sym_heap_size,
 			  scm_from_ulong (local_scm_heap_size)),
 		scm_cons (sym_mallocated,
diff --git a/libguile/gc.h b/libguile/gc.h
index 439cf8a4b..821d174d6 100644
--- a/libguile/gc.h
+++ b/libguile/gc.h
@@ -278,10 +278,12 @@ SCM_API unsigned long scm_gc_cells_collected;
 SCM_API unsigned long scm_gc_malloc_collected;
 SCM_API unsigned long scm_gc_ports_collected;
 SCM_API unsigned long scm_cells_allocated;
+SCM_API unsigned long scm_last_cells_allocated;
 SCM_API int scm_gc_cell_yield_percentage;
 SCM_API int scm_gc_malloc_yield_percentage;
 SCM_API unsigned long scm_mallocated;
 SCM_API unsigned long scm_mtrigger;
+SCM_API double scm_gc_cells_allocated_acc;