---

yaml
---
r: 261662
b: refs/heads/master
c: 1d07171
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 013e896373fc53f3d3c039364a25ccbd1fc0729a
+refs/heads/master: 1d07171c5e58e68a76a141970a3a5e816a414ce6

trunk/mm/slub.c

@@ -354,6 +354,42 @@ static __always_inline void slab_unlock(struct page *page)
 	__bit_spin_unlock(PG_locked, &page->flags);
 }
 
+/* Interrupts must be disabled (for the fallback code to work right) */
+static inline bool __cmpxchg_double_slab(struct kmem_cache *s, struct page *page,
+		void *freelist_old, unsigned long counters_old,
+		void *freelist_new, unsigned long counters_new,
+		const char *n)
+{
+	VM_BUG_ON(!irqs_disabled());
+#ifdef CONFIG_CMPXCHG_DOUBLE
+	if (s->flags & __CMPXCHG_DOUBLE) {
+		if (cmpxchg_double(&page->freelist,
+			freelist_old, counters_old,
+			freelist_new, counters_new))
+		return 1;
+	} else
+#endif
+	{
+		slab_lock(page);
+		if (page->freelist == freelist_old && page->counters == counters_old) {
+			page->freelist = freelist_new;
+			page->counters = counters_new;
+			slab_unlock(page);
+			return 1;
+		}
+		slab_unlock(page);
+	}
+
+	cpu_relax();
+	stat(s, CMPXCHG_DOUBLE_FAIL);
+
+#ifdef SLUB_DEBUG_CMPXCHG
+	printk(KERN_INFO "%s %s: cmpxchg double redo ", n, s->name);
+#endif
+
+	return 0;
+}
+
 static inline bool cmpxchg_double_slab(struct kmem_cache *s, struct page *page,
 		void *freelist_old, unsigned long counters_old,
 		void *freelist_new, unsigned long counters_new,
@@ -368,14 +404,19 @@ static inline bool cmpxchg_double_slab(struct kmem_cache *s, struct page *page,
 	} else
 #endif
 	{
+		unsigned long flags;
+
+		local_irq_save(flags);
 		slab_lock(page);
 		if (page->freelist == freelist_old && page->counters == counters_old) {
 			page->freelist = freelist_new;
 			page->counters = counters_new;
 			slab_unlock(page);
+			local_irq_restore(flags);
 			return 1;
 		}
 		slab_unlock(page);
+		local_irq_restore(flags);
 	}
 
 	cpu_relax();
@@ -1471,7 +1512,7 @@ static inline int acquire_slab(struct kmem_cache *s,
 		VM_BUG_ON(new.frozen);
 		new.frozen = 1;
 
-	} while (!cmpxchg_double_slab(s, page,
+	} while (!__cmpxchg_double_slab(s, page,
 			freelist, counters,
 			NULL, new.counters,
 			"lock and freeze"));
@@ -1709,7 +1750,7 @@ static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
 			new.inuse--;
 			VM_BUG_ON(!new.frozen);
 
-		} while (!cmpxchg_double_slab(s, page,
+		} while (!__cmpxchg_double_slab(s, page,
 			prior, counters,
 			freelist, new.counters,
 			"drain percpu freelist"));
@@ -1798,7 +1839,7 @@ static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
 	}
 
 	l = m;
-	if (!cmpxchg_double_slab(s, page,
+	if (!__cmpxchg_double_slab(s, page,
 				old.freelist, old.counters,
 				new.freelist, new.counters,
 				"unfreezing slab"))
@@ -1992,7 +2033,7 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
 		new.inuse = page->objects;
 		new.frozen = object != NULL;
 
-	} while (!cmpxchg_double_slab(s, page,
+	} while (!__cmpxchg_double_slab(s, page,
 			object, counters,
 			NULL, new.counters,
 			"__slab_alloc"));