---

yaml
---
r: 60732
b: refs/heads/master
c: 6300ea7
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 68dff6a9af9f27df5aeee6d0339818b0e36c1b51
+refs/heads/master: 6300ea75031e7aebfe3331245b7f750d82621223

trunk/mm/slub.c

@@ -205,6 +205,11 @@ static inline void ClearSlabDebug(struct page *page)
 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
 #endif
 
+/*
+ * The page->inuse field is 16 bit thus we have this limitation
+ */
+#define MAX_OBJECTS_PER_SLAB 65535
+
 /* Internal SLUB flags */
 #define __OBJECT_POISON 0x80000000	/* Poison object */
 
@@ -1736,8 +1741,17 @@ static inline int slab_order(int size, int min_objects,
 {
 	int order;
 	int rem;
+	int min_order = slub_min_order;
 
-	for (order = max(slub_min_order,
+	/*
+	 * If we would create too many object per slab then reduce
+	 * the slab order even if it goes below slub_min_order.
+	 */
+	while (min_order > 0 &&
+		(PAGE_SIZE << min_order) >= MAX_OBJECTS_PER_SLAB * size)
+			min_order--;
+
+	for (order = max(min_order,
 				fls(min_objects * size - 1) - PAGE_SHIFT);
 			order <= max_order; order++) {
 
@@ -1751,6 +1765,9 @@ static inline int slab_order(int size, int min_objects,
 		if (rem <= slab_size / fract_leftover)
 			break;
 
+		/* If the next size is too high then exit now */
+		if (slab_size * 2 >= MAX_OBJECTS_PER_SLAB * size)
+			break;
 	}
 
 	return order;
@@ -2037,7 +2054,7 @@ static int calculate_sizes(struct kmem_cache *s)
 	 * The page->inuse field is only 16 bit wide! So we cannot have
 	 * more than 64k objects per slab.
 	 */
-	if (!s->objects || s->objects > 65535)
+	if (!s->objects || s->objects > MAX_OBJECTS_PER_SLAB)
 		return 0;
 	return 1;