[ruby-dev:34162] GC heap size less patch

authorNariです。

この前に話しにあった、ヒープの細分化のパッチを作りました。

詳細はこちらに書いております。
http://d.hatena.ne.jp/authorNari/20080328/1206675485

もっとベンチマーク用のコードを作って精査する必要がありますが
pre版という事で、よろしくお願いします。

---
id: authorNari

---
Index: gc.c
===================================================================
--- gc.c	(リビジョン 15844)
+++ gc.c	(作業コピー)
@@ -143,7 +143,6 @@
 static RVALUE *freelist = 0;
 static RVALUE *deferred_final_list = 0;

-#define HEAPS_INCREMENT 10
 static struct heaps_slot {
     void *membase;
     RVALUE *slot;
@@ -153,9 +152,27 @@
 static int heaps_used   = 0;

 #define HEAP_MIN_SLOTS 10000
-static int heap_slots = HEAP_MIN_SLOTS;
+static int add_objects = HEAP_MIN_SLOTS;

+/* tiny heap size */
+// 32KB
+#define HEAP_SIZE 0x8000
+// 128KB
+//#define HEAP_SIZE 0x20000
+// 64KB
+//#define HEAP_SIZE 0x10000
+// 16KB
+//#define HEAP_SIZE 0x4000
+// 8KB
+//#define HEAP_SIZE 0x2000
+// 4KB
+//#define HEAP_SIZE 0x1000
+// 2KB
+//#define HEAP_SIZE 0x800
+
+#define HEAP_OBJ_LIMIT (HEAP_SIZE / sizeof(struct RVALUE))
 #define FREE_MIN  4096
+static int add_inc_time = 0;

 static RVALUE *himem, *lomem;

@@ -179,8 +196,6 @@
 size_t rb_gc_stack_maxsize = 655300*sizeof(VALUE);
 #endif

-
-
 static void run_final(VALUE obj);
 static int garbage_collect(void);

@@ -417,43 +432,39 @@
     }
 }

+
 static void
-add_heap(void)
+allocate_heaps(void)
 {
+    struct heaps_slot *p;
+    int length;
+
+    heaps_length += add_objects / HEAP_OBJ_LIMIT;
+    length = heaps_length*sizeof(struct heaps_slot);
+    RUBY_CRITICAL(
+		  if (heaps_used > 0) {
+		      p = (struct heaps_slot *)realloc(heaps, length);
+		      if (p) heaps = p;
+		  }
+		  else {
+		      p = heaps = (struct heaps_slot *)malloc(length);
+		  }
+		  );
+    if (p == 0) rb_memerror();
+}
+
+static void
+assign_heap_slot(void)
+{
     RVALUE *p, *pend, *membase;
     long hi, lo, mid;
+    int objs;
+	
+    objs = HEAP_OBJ_LIMIT;
+    RUBY_CRITICAL(p = (RVALUE*)malloc(HEAP_SIZE));
+    if (p == 0)
+	rb_memerror();

-    if (heaps_used == heaps_length) {
-	/* Realloc heaps */
-	struct heaps_slot *p;
-	int length;
-
-	heaps_length += HEAPS_INCREMENT;
-	length = heaps_length*sizeof(struct heaps_slot);
-	RUBY_CRITICAL(
-	    if (heaps_used > 0) {
-		p = (struct heaps_slot *)realloc(heaps, length);
-		if (p) heaps = p;
-	    }
-	    else {
-		p = heaps = (struct heaps_slot *)malloc(length);
-	    });
-	if (p == 0) rb_memerror();
-    }
-
-    for (;;) {
-	RUBY_CRITICAL(p = (RVALUE*)malloc(sizeof(RVALUE)*(heap_slots+1)));
-	if (p == 0) {
-	    if (heap_slots == HEAP_MIN_SLOTS) {
-		rb_memerror();
-	    }
-	    heap_slots = HEAP_MIN_SLOTS;
-	}
-	else {
-	    break;
-	}
-    }
-
     lo = 0;
     hi = heaps_used;
     while (lo < hi) {
@@ -471,21 +482,25 @@
     }

     membase = p;
-    if ((VALUE)p % sizeof(RVALUE) == 0)
-	heap_slots += 1;
-    else
+
+    if ((VALUE)p % sizeof(RVALUE) != 0) {
 	p = (RVALUE*)((VALUE)p + sizeof(RVALUE) - ((VALUE)p % sizeof(RVALUE)));
+	if ((membase + HEAP_SIZE) < (p + HEAP_SIZE)) {
+	    objs--;
+	}
+    }
+    	
+
     if (hi < heaps_used) {
 	MEMMOVE(&heaps[hi+1], &heaps[hi], struct heaps_slot, heaps_used - hi);
     }
     heaps[hi].membase = membase;
     heaps[hi].slot = p;
-    heaps[hi].limit = heap_slots;
-    pend = p + heap_slots;
+    heaps[hi].limit = objs;
+    pend = p + objs;
     if (lomem == 0 || lomem > p) lomem = p;
     if (himem < pend) himem = pend;
     heaps_used++;
-    heap_slots *= 1.8;

     while (p < pend) {
 	p->as.free.flags = 0;
@@ -495,15 +510,56 @@
     }
 }

+static void
+add_heap(void)
+{
+    int add, i;
+
+    add = add_objects / HEAP_OBJ_LIMIT;
+    add_objects *= 1.8;
+
+    if ((heaps_used + add) > heaps_length) {
+    	allocate_heaps();
+    }
+
+    for (i = 0; i < add; i++) {
+    	assign_heap_slot();
+    }
+    add_inc_time = 0;
+}
+
+
+static void
+set_add_inc_time(void)
+{
+    add_inc_time += add_objects / HEAP_OBJ_LIMIT;
+    add_objects *= 1.8;
+
+    if ((heaps_used + add_inc_time) > heaps_length) {
+	allocate_heaps();
+    }
+}
+
+static int
+add_heap_increment(void)
+{
+    if (add_inc_time > 0) {
+	assign_heap_slot();
+	add_inc_time--;
+	return Qtrue;
+    }
+    return Qfalse;
+}
+
 #define RANY(o) ((RVALUE*)(o))

 static VALUE
 rb_newobj_from_heap(void)
 {
     VALUE obj;
-
+	
     if (ruby_gc_stress || !freelist) {
-	if(!garbage_collect()) {
+    	if (!add_heap_increment() && !garbage_collect()) {
 	    rb_memerror();
 	}
     }
@@ -516,6 +572,7 @@
     RANY(obj)->file = rb_sourcefile();
     RANY(obj)->line = rb_sourceline();
 #endif
+
     return obj;
 }

@@ -1202,6 +1259,9 @@
 	    j++;
 	}
     }
+    if (i != j)	{
+	add_objects = heaps_used * HEAP_OBJ_LIMIT;
+    }
 }

 void rb_gc_abort_threads(void);
@@ -1212,15 +1272,14 @@
     RVALUE *p, *pend, *final_list;
     int freed = 0;
     int i;
-    unsigned long live = 0;
-    unsigned long free_min = 0;
+    unsigned long live = 0, free_min = 0, do_heap_free = 0;

-    for (i = 0; i < heaps_used; i++) {
-        free_min += heaps[i].limit;
+    do_heap_free = (heaps_used * HEAP_OBJ_LIMIT) * 0.65;
+    free_min = (heaps_used * HEAP_OBJ_LIMIT)  * 0.2;
+    if (free_min < FREE_MIN) {
+	do_heap_free = heaps_used * HEAP_OBJ_LIMIT;
+        free_min = FREE_MIN;
     }
-    free_min = free_min * 0.2;
-    if (free_min < FREE_MIN)
-        free_min = FREE_MIN;

     if (source_filenames) {
         st_foreach(source_filenames, sweep_source_filename, 0);
@@ -1263,7 +1322,7 @@
 	    }
 	    p++;
 	}
-	if (n == heaps[i].limit && freed > free_min) {
+	if (n == heaps[i].limit && freed > do_heap_free) {
 	    RVALUE *pp;

 	    heaps[i].limit = 0;
@@ -1282,7 +1341,8 @@
     }
     malloc_increase = 0;
     if (freed < free_min) {
-	add_heap();
+    	set_add_inc_time();
+	add_heap_increment();
     }
     during_gc = 0;

@@ -1572,6 +1632,7 @@
     }

     gc_sweep();
+
     if (GC_NOTIFY) printf("end garbage_collect()\n");
     return Qtrue;
 }