1 files changed, 104 insertions, 233 deletions

diff --git a/mm/slub.c b/mm/slub.c
index 8d71aaf888d7..0bfd3863d521 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -151,7 +151,8 @@
  * Set of flags that will prevent slab merging
  */
 #define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
-                SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE)
+                SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \
+                SLAB_FAILSLAB)
 
 #define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \
                 SLAB_CACHE_DMA | SLAB_NOTRACK)
@@ -217,10 +218,10 @@ static inline void sysfs_slab_remove(struct kmem_cache *s)
 
 #endif
 
-static inline void stat(struct kmem_cache_cpu *c, enum stat_item si)
+static inline void stat(struct kmem_cache *s, enum stat_item si)
 {
 #ifdef CONFIG_SLUB_STATS
-        c->stat[si]++;
+        __this_cpu_inc(s->cpu_slab->stat[si]);
 #endif
 }
 
@@ -242,15 +243,6 @@ static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
 #endif
 }
 
-static inline struct kmem_cache_cpu *get_cpu_slab(struct kmem_cache *s, int cpu)
-{
-#ifdef CONFIG_SMP
-        return s->cpu_slab[cpu];
-#else
-        return &s->cpu_slab;
-#endif
-}
-
 /* Verify that a pointer has an address that is valid within a slab page */
 static inline int check_valid_pointer(struct kmem_cache *s,
                                 struct page *page, const void *object)
@@ -269,13 +261,6 @@ static inline int check_valid_pointer(struct kmem_cache *s,
         return 1;
 }
 
-/*
- * Slow version of get and set free pointer.
- *
- * This version requires touching the cache lines of kmem_cache which
- * we avoid to do in the fast alloc free paths. There we obtain the offset
- * from the page struct.
- */
 static inline void *get_freepointer(struct kmem_cache *s, void *object)
 {
         return *(void **)(object + s->offset);
@@ -1020,6 +1005,9 @@ static int __init setup_slub_debug(char *str)
                 case 't':
                         slub_debug |= SLAB_TRACE;
                         break;
+                case 'a':
+                        slub_debug |= SLAB_FAILSLAB;
+                        break;
                 default:
                         printk(KERN_ERR "slub_debug option '%c' "
                                 "unknown. skipped\n", *str);
@@ -1124,7 +1112,7 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
                 if (!page)
                         return NULL;
 
-                stat(get_cpu_slab(s, raw_smp_processor_id()), ORDER_FALLBACK);
+                stat(s, ORDER_FALLBACK);
         }
 
         if (kmemcheck_enabled
@@ -1422,23 +1410,22 @@ static struct page *get_partial(struct kmem_cache *s, gfp_t flags, int node)
 static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail)
 {
         struct kmem_cache_node *n = get_node(s, page_to_nid(page));
-        struct kmem_cache_cpu *c = get_cpu_slab(s, smp_processor_id());
 
         __ClearPageSlubFrozen(page);
         if (page->inuse) {
 
                 if (page->freelist) {
                         add_partial(n, page, tail);
-                        stat(c, tail ? DEACTIVATE_TO_TAIL : DEACTIVATE_TO_HEAD);
+                        stat(s, tail ? DEACTIVATE_TO_TAIL : DEACTIVATE_TO_HEAD);
                 } else {
-                        stat(c, DEACTIVATE_FULL);
+                        stat(s, DEACTIVATE_FULL);
                         if (SLABDEBUG && PageSlubDebug(page) &&
                                                 (s->flags & SLAB_STORE_USER))
                                 add_full(n, page);
                 }
                 slab_unlock(page);
         } else {
-                stat(c, DEACTIVATE_EMPTY);
+                stat(s, DEACTIVATE_EMPTY);
                 if (n->nr_partial < s->min_partial) {
                         /*
                          * Adding an empty slab to the partial slabs in order
@@ -1454,7 +1441,7 @@ static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail)
                         slab_unlock(page);
                 } else {
                         slab_unlock(page);
-                        stat(get_cpu_slab(s, raw_smp_processor_id()), FREE_SLAB);
+                        stat(s, FREE_SLAB);
                         discard_slab(s, page);
                 }
         }
@@ -1469,7 +1456,7 @@ static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
         int tail = 1;
 
         if (page->freelist)
-                stat(c, DEACTIVATE_REMOTE_FREES);
+                stat(s, DEACTIVATE_REMOTE_FREES);
         /*
          * Merge cpu freelist into slab freelist. Typically we get here
          * because both freelists are empty. So this is unlikely
@@ -1482,10 +1469,10 @@ static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
 
                 /* Retrieve object from cpu_freelist */
                 object = c->freelist;
-                c->freelist = c->freelist[c->offset];
+                c->freelist = get_freepointer(s, c->freelist);
 
                 /* And put onto the regular freelist */
-                object[c->offset] = page->freelist;
+                set_freepointer(s, object, page->freelist);
                 page->freelist = object;
                 page->inuse--;
         }
@@ -1495,7 +1482,7 @@ static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
 
 static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
 {
-        stat(c, CPUSLAB_FLUSH);
+        stat(s, CPUSLAB_FLUSH);
         slab_lock(c->page);
         deactivate_slab(s, c);
 }
@@ -1507,7 +1494,7 @@ static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
  */
 static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu)
 {
-        struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
+        struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
 
         if (likely(c && c->page))
                 flush_slab(s, c);
@@ -1635,7 +1622,7 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
         if (unlikely(!node_match(c, node)))
                 goto another_slab;
 
-        stat(c, ALLOC_REFILL);
+        stat(s, ALLOC_REFILL);
 
 load_freelist:
         object = c->page->freelist;
@@ -1644,13 +1631,13 @@ load_freelist:
         if (unlikely(SLABDEBUG && PageSlubDebug(c->page)))
                 goto debug;
 
-        c->freelist = object[c->offset];
+        c->freelist = get_freepointer(s, object);
         c->page->inuse = c->page->objects;
         c->page->freelist = NULL;
         c->node = page_to_nid(c->page);
 unlock_out:
         slab_unlock(c->page);
-        stat(c, ALLOC_SLOWPATH);
+        stat(s, ALLOC_SLOWPATH);
         return object;
 
 another_slab:
@@ -1660,7 +1647,7 @@ new_slab:
         new = get_partial(s, gfpflags, node);
         if (new) {
                 c->page = new;
-                stat(c, ALLOC_FROM_PARTIAL);
+                stat(s, ALLOC_FROM_PARTIAL);
                 goto load_freelist;
         }
 
@@ -1673,8 +1660,8 @@ new_slab:
                 local_irq_disable();
 
         if (new) {
-                c = get_cpu_slab(s, smp_processor_id());
-                stat(c, ALLOC_SLAB);
+                c = __this_cpu_ptr(s->cpu_slab);
+                stat(s, ALLOC_SLAB);
                 if (c->page)
                         flush_slab(s, c);
                 slab_lock(new);
@@ -1690,7 +1677,7 @@ debug:
                 goto another_slab;
 
         c->page->inuse++;
-        c->page->freelist = object[c->offset];
+        c->page->freelist = get_freepointer(s, object);
         c->node = -1;
         goto unlock_out;
 }
@@ -1711,35 +1698,33 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
         void **object;
         struct kmem_cache_cpu *c;
         unsigned long flags;
-        unsigned int objsize;
 
         gfpflags &= gfp_allowed_mask;
 
         lockdep_trace_alloc(gfpflags);
         might_sleep_if(gfpflags & __GFP_WAIT);
 
-        if (should_failslab(s->objsize, gfpflags))
+        if (should_failslab(s->objsize, gfpflags, s->flags))
                 return NULL;
 
         local_irq_save(flags);
-        c = get_cpu_slab(s, smp_processor_id());
-        objsize = c->objsize;
-        if (unlikely(!c->freelist || !node_match(c, node)))
+        c = __this_cpu_ptr(s->cpu_slab);
+        object = c->freelist;
+        if (unlikely(!object || !node_match(c, node)))
 
                 object = __slab_alloc(s, gfpflags, node, addr, c);
 
         else {
-                object = c->freelist;
-                c->freelist = object[c->offset];
-                stat(c, ALLOC_FASTPATH);
+                c->freelist = get_freepointer(s, object);
+                stat(s, ALLOC_FASTPATH);
         }
         local_irq_restore(flags);
 
         if (unlikely(gfpflags & __GFP_ZERO) && object)
-                memset(object, 0, objsize);
+                memset(object, 0, s->objsize);
 
-        kmemcheck_slab_alloc(s, gfpflags, object, c->objsize);
-        kmemleak_alloc_recursive(object, objsize, 1, s->flags, gfpflags);
+        kmemcheck_slab_alloc(s, gfpflags, object, s->objsize);
+        kmemleak_alloc_recursive(object, s->objsize, 1, s->flags, gfpflags);
 
         return object;
 }
@@ -1794,26 +1779,25 @@ EXPORT_SYMBOL(kmem_cache_alloc_node_notrace);
  * handling required then we can return immediately.
  */
 static void __slab_free(struct kmem_cache *s, struct page *page,
-                        void *x, unsigned long addr, unsigned int offset)
+                        void *x, unsigned long addr)
 {
         void *prior;
         void **object = (void *)x;
-        struct kmem_cache_cpu *c;
 
-        c = get_cpu_slab(s, raw_smp_processor_id());
-        stat(c, FREE_SLOWPATH);
+        stat(s, FREE_SLOWPATH);
         slab_lock(page);
 
         if (unlikely(SLABDEBUG && PageSlubDebug(page)))
                 goto debug;
 
 checks_ok:
-        prior = object[offset] = page->freelist;
+        prior = page->freelist;
+        set_freepointer(s, object, prior);
         page->freelist = object;
         page->inuse--;
 
         if (unlikely(PageSlubFrozen(page))) {
-                stat(c, FREE_FROZEN);
+                stat(s, FREE_FROZEN);
                 goto out_unlock;
         }
 
@@ -1826,7 +1810,7 @@ checks_ok:
          */
         if (unlikely(!prior)) {
                 add_partial(get_node(s, page_to_nid(page)), page, 1);
-                stat(c, FREE_ADD_PARTIAL);
+                stat(s, FREE_ADD_PARTIAL);
         }
 
 out_unlock:
@@ -1839,10 +1823,10 @@ slab_empty:
                  * Slab still on the partial list.
                  */
                 remove_partial(s, page);
-                stat(c, FREE_REMOVE_PARTIAL);
+                stat(s, FREE_REMOVE_PARTIAL);
         }
         slab_unlock(page);
-        stat(c, FREE_SLAB);
+        stat(s, FREE_SLAB);
         discard_slab(s, page);
         return;
 
@@ -1872,17 +1856,17 @@ static __always_inline void slab_free(struct kmem_cache *s,
 
         kmemleak_free_recursive(x, s->flags);
         local_irq_save(flags);
-        c = get_cpu_slab(s, smp_processor_id());
-        kmemcheck_slab_free(s, object, c->objsize);
-        debug_check_no_locks_freed(object, c->objsize);
+        c = __this_cpu_ptr(s->cpu_slab);
+        kmemcheck_slab_free(s, object, s->objsize);
+        debug_check_no_locks_freed(object, s->objsize);
         if (!(s->flags & SLAB_DEBUG_OBJECTS))
-                debug_check_no_obj_freed(object, c->objsize);
+                debug_check_no_obj_freed(object, s->objsize);
         if (likely(page == c->page && c->node >= 0)) {
-                object[c->offset] = c->freelist;
+                set_freepointer(s, object, c->freelist);
                 c->freelist = object;
-                stat(c, FREE_FASTPATH);
+                stat(s, FREE_FASTPATH);
         } else
-                __slab_free(s, page, x, addr, c->offset);
+                __slab_free(s, page, x, addr);
 
         local_irq_restore(flags);
 }
@@ -2069,19 +2053,6 @@ static unsigned long calculate_alignment(unsigned long flags,
         return ALIGN(align, sizeof(void *));
 }
 
-static void init_kmem_cache_cpu(struct kmem_cache *s,
-                        struct kmem_cache_cpu *c)
-{
-        c->page = NULL;
-        c->freelist = NULL;
-        c->node = 0;
-        c->offset = s->offset / sizeof(void *);
-        c->objsize = s->objsize;
-#ifdef CONFIG_SLUB_STATS
-        memset(c->stat, 0, NR_SLUB_STAT_ITEMS * sizeof(unsigned));
-#endif
-}
-
 static void
 init_kmem_cache_node(struct kmem_cache_node *n, struct kmem_cache *s)
 {
@@ -2095,130 +2066,24 @@ init_kmem_cache_node(struct kmem_cache_node *n, struct kmem_cache *s)
 #endif
 }
 
-#ifdef CONFIG_SMP
-/*
- * Per cpu array for per cpu structures.
- *
- * The per cpu array places all kmem_cache_cpu structures from one processor
- * close together meaning that it becomes possible that multiple per cpu
- * structures are contained in one cacheline. This may be particularly
- * beneficial for the kmalloc caches.
- *
- * A desktop system typically has around 60-80 slabs. With 100 here we are
- * likely able to get per cpu structures for all caches from the array defined
- * here. We must be able to cover all kmalloc caches during bootstrap.
- *
- * If the per cpu array is exhausted then fall back to kmalloc
- * of individual cachelines. No sharing is possible then.
- */
-#define NR_KMEM_CACHE_CPU 100
-
-static DEFINE_PER_CPU(struct kmem_cache_cpu [NR_KMEM_CACHE_CPU],
-                      kmem_cache_cpu);
-
-static DEFINE_PER_CPU(struct kmem_cache_cpu *, kmem_cache_cpu_free);
-static DECLARE_BITMAP(kmem_cach_cpu_free_init_once, CONFIG_NR_CPUS);
-
-static struct kmem_cache_cpu *alloc_kmem_cache_cpu(struct kmem_cache *s,
-                                                        int cpu, gfp_t flags)
-{
-        struct kmem_cache_cpu *c = per_cpu(kmem_cache_cpu_free, cpu);
-
-        if (c)
-                per_cpu(kmem_cache_cpu_free, cpu) =
-                                (void *)c->freelist;
-        else {
-                /* Table overflow: So allocate ourselves */
-                c = kmalloc_node(
-                        ALIGN(sizeof(struct kmem_cache_cpu), cache_line_size()),
-                        flags, cpu_to_node(cpu));
-                if (!c)
-                        return NULL;
-        }
-
-        init_kmem_cache_cpu(s, c);
-        return c;
-}
-
-static void free_kmem_cache_cpu(struct kmem_cache_cpu *c, int cpu)
-{
-        if (c < per_cpu(kmem_cache_cpu, cpu) ||
-                        c >= per_cpu(kmem_cache_cpu, cpu) + NR_KMEM_CACHE_CPU) {
-                kfree(c);
-                return;
-        }
-        c->freelist = (void *)per_cpu(kmem_cache_cpu_free, cpu);
-        per_cpu(kmem_cache_cpu_free, cpu) = c;
-}
-
-static void free_kmem_cache_cpus(struct kmem_cache *s)
-{
-        int cpu;
-
-        for_each_online_cpu(cpu) {
-                struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
-
-                if (c) {
-                        s->cpu_slab[cpu] = NULL;
-                        free_kmem_cache_cpu(c, cpu);
-                }
-        }
-}
-
-static int alloc_kmem_cache_cpus(struct kmem_cache *s, gfp_t flags)
-{
-        int cpu;
-
-        for_each_online_cpu(cpu) {
-                struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
-
-                if (c)
-                        continue;
-
-                c = alloc_kmem_cache_cpu(s, cpu, flags);
-                if (!c) {
-                        free_kmem_cache_cpus(s);
-                        return 0;
-                }
-                s->cpu_slab[cpu] = c;
-        }
-        return 1;
-}
-
-/*
- * Initialize the per cpu array.
- */
-static void init_alloc_cpu_cpu(int cpu)
-{
-        int i;
+static DEFINE_PER_CPU(struct kmem_cache_cpu, kmalloc_percpu[KMALLOC_CACHES]);
 
-        if (cpumask_test_cpu(cpu, to_cpumask(kmem_cach_cpu_free_init_once)))
-                return;
-
-        for (i = NR_KMEM_CACHE_CPU - 1; i >= 0; i--)
-                free_kmem_cache_cpu(&per_cpu(kmem_cache_cpu, cpu)[i], cpu);
-
-        cpumask_set_cpu(cpu, to_cpumask(kmem_cach_cpu_free_init_once));
-}
-
-static void __init init_alloc_cpu(void)
+static inline int alloc_kmem_cache_cpus(struct kmem_cache *s, gfp_t flags)
 {
-        int cpu;
-
-        for_each_online_cpu(cpu)
-                init_alloc_cpu_cpu(cpu);
-  }
+        if (s < kmalloc_caches + KMALLOC_CACHES && s >= kmalloc_caches)
+                /*
+                 * Boot time creation of the kmalloc array. Use static per cpu data
+                 * since the per cpu allocator is not available yet.
+                 */
+                s->cpu_slab = kmalloc_percpu + (s - kmalloc_caches);
+        else
+                s->cpu_slab =  alloc_percpu(struct kmem_cache_cpu);
 
-#else
-static inline void free_kmem_cache_cpus(struct kmem_cache *s) {}
-static inline void init_alloc_cpu(void) {}
+        if (!s->cpu_slab)
+                return 0;
 
-static inline int alloc_kmem_cache_cpus(struct kmem_cache *s, gfp_t flags)
-{
-        init_kmem_cache_cpu(s, &s->cpu_slab);
         return 1;
 }
-#endif
 
 #ifdef CONFIG_NUMA
 /*
@@ -2287,7 +2152,8 @@ static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags)
         int node;
         int local_node;
 
-        if (slab_state >= UP)
+        if (slab_state >= UP && (s < kmalloc_caches ||
+                        s > kmalloc_caches + KMALLOC_CACHES))
                 local_node = page_to_nid(virt_to_page(s));
         else
                 local_node = 0;
@@ -2502,6 +2368,7 @@ static int kmem_cache_open(struct kmem_cache *s, gfp_t gfpflags,
 
         if (alloc_kmem_cache_cpus(s, gfpflags & ~SLUB_DMA))
                 return 1;
+
         free_kmem_cache_nodes(s);
 error:
         if (flags & SLAB_PANIC)
@@ -2609,9 +2476,8 @@ static inline int kmem_cache_close(struct kmem_cache *s)
         int node;
 
         flush_all(s);
-
+        free_percpu(s->cpu_slab);
         /* Attempt to free all objects */
-        free_kmem_cache_cpus(s);
         for_each_node_state(node, N_NORMAL_MEMORY) {
                 struct kmem_cache_node *n = get_node(s, node);
 
@@ -2651,7 +2517,7 @@ EXPORT_SYMBOL(kmem_cache_destroy);
  *              Kmalloc subsystem
  *******************************************************************/
 
-struct kmem_cache kmalloc_caches[SLUB_PAGE_SHIFT] __cacheline_aligned;
+struct kmem_cache kmalloc_caches[KMALLOC_CACHES] __cacheline_aligned;
 EXPORT_SYMBOL(kmalloc_caches);
 
 static int __init setup_slub_min_order(char *str)
@@ -2741,6 +2607,7 @@ static noinline struct kmem_cache *dma_kmalloc_cache(int index, gfp_t flags)
         char *text;
         size_t realsize;
         unsigned long slabflags;
+        int i;
 
         s = kmalloc_caches_dma[index];
         if (s)
@@ -2760,7 +2627,14 @@ static noinline struct kmem_cache *dma_kmalloc_cache(int index, gfp_t flags)
         realsize = kmalloc_caches[index].objsize;
         text = kasprintf(flags & ~SLUB_DMA, "kmalloc_dma-%d",
                          (unsigned int)realsize);
-        s = kmalloc(kmem_size, flags & ~SLUB_DMA);
+
+        s = NULL;
+        for (i = 0; i < KMALLOC_CACHES; i++)
+                if (!kmalloc_caches[i].size)
+                        break;
+
+        BUG_ON(i >= KMALLOC_CACHES);
+        s = kmalloc_caches + i;
 
         /*
          * Must defer sysfs creation to a workqueue because we don't know
@@ -2772,9 +2646,9 @@ static noinline struct kmem_cache *dma_kmalloc_cache(int index, gfp_t flags)
         if (slab_state >= SYSFS)
                 slabflags |= __SYSFS_ADD_DEFERRED;
 
-        if (!s || !text || !kmem_cache_open(s, flags, text,
+        if (!text || !kmem_cache_open(s, flags, text,
                         realsize, ARCH_KMALLOC_MINALIGN, slabflags, NULL)) {
-                kfree(s);
+                s->size = 0;
                 kfree(text);
                 goto unlock_out;
         }
@@ -3176,8 +3050,6 @@ void __init kmem_cache_init(void)
         int i;
         int caches = 0;
 
-        init_alloc_cpu();
-
 #ifdef CONFIG_NUMA
         /*
          * Must first have the slab cache available for the allocations of the
@@ -3261,8 +3133,10 @@ void __init kmem_cache_init(void)
 
 #ifdef CONFIG_SMP
         register_cpu_notifier(&slab_notifier);
-        kmem_size = offsetof(struct kmem_cache, cpu_slab) +
-                                nr_cpu_ids * sizeof(struct kmem_cache_cpu *);
+#endif
+#ifdef CONFIG_NUMA
+        kmem_size = offsetof(struct kmem_cache, node) +
+                                nr_node_ids * sizeof(struct kmem_cache_node *);
 #else
         kmem_size = sizeof(struct kmem_cache);
 #endif
@@ -3351,22 +3225,12 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size,
         down_write(&slub_lock);
         s = find_mergeable(size, align, flags, name, ctor);
         if (s) {
-                int cpu;
-
                 s->refcount++;
                 /*
                  * Adjust the object sizes so that we clear
                  * the complete object on kzalloc.
                  */
                 s->objsize = max(s->objsize, (int)size);
-
-                /*
-                 * And then we need to update the object size in the
-                 * per cpu structures
-                 */
-                for_each_online_cpu(cpu)
-                        get_cpu_slab(s, cpu)->objsize = s->objsize;
-
                 s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *)));
                 up_write(&slub_lock);
 
@@ -3420,29 +3284,15 @@ static int __cpuinit slab_cpuup_callback(struct notifier_block *nfb,
         unsigned long flags;
 
         switch (action) {
-        case CPU_UP_PREPARE:
-        case CPU_UP_PREPARE_FROZEN:
-                init_alloc_cpu_cpu(cpu);
-                down_read(&slub_lock);
-                list_for_each_entry(s, &slab_caches, list)
-                        s->cpu_slab[cpu] = alloc_kmem_cache_cpu(s, cpu,
-                                                        GFP_KERNEL);
-                up_read(&slub_lock);
-                break;
-
         case CPU_UP_CANCELED:
         case CPU_UP_CANCELED_FROZEN:
         case CPU_DEAD:
         case CPU_DEAD_FROZEN:
                 down_read(&slub_lock);
                 list_for_each_entry(s, &slab_caches, list) {
-                        struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
-
                         local_irq_save(flags);
                         __flush_cpu_slab(s, cpu);
                         local_irq_restore(flags);
-                        free_kmem_cache_cpu(c, cpu);
-                        s->cpu_slab[cpu] = NULL;
                 }
                 up_read(&slub_lock);
                 break;
@@ -3928,7 +3778,7 @@ static ssize_t show_slab_objects(struct kmem_cache *s,
                 int cpu;
 
                 for_each_possible_cpu(cpu) {
-                        struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
+                        struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
 
                         if (!c || c->node < 0)
                                 continue;
@@ -4171,6 +4021,23 @@ static ssize_t trace_store(struct kmem_cache *s, const char *buf,
 }
 SLAB_ATTR(trace);
 
+#ifdef CONFIG_FAILSLAB
+static ssize_t failslab_show(struct kmem_cache *s, char *buf)
+{
+        return sprintf(buf, "%d\n", !!(s->flags & SLAB_FAILSLAB));
+}
+
+static ssize_t failslab_store(struct kmem_cache *s, const char *buf,
+                                                        size_t length)
+{
+        s->flags &= ~SLAB_FAILSLAB;
+        if (buf[0] == '1')
+                s->flags |= SLAB_FAILSLAB;
+        return length;
+}
+SLAB_ATTR(failslab);
+#endif
+
 static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf)
 {
         return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT));
@@ -4353,7 +4220,7 @@ static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si)
                 return -ENOMEM;
 
         for_each_online_cpu(cpu) {
-                unsigned x = get_cpu_slab(s, cpu)->stat[si];
+                unsigned x = per_cpu_ptr(s->cpu_slab, cpu)->stat[si];
 
                 data[cpu] = x;
                 sum += x;
@@ -4376,7 +4243,7 @@ static void clear_stat(struct kmem_cache *s, enum stat_item si)
         int cpu;
 
         for_each_online_cpu(cpu)
-                get_cpu_slab(s, cpu)->stat[si] = 0;
+                per_cpu_ptr(s->cpu_slab, cpu)->stat[si] = 0;
 }
 
 #define STAT_ATTR(si, text)                                     \
@@ -4467,6 +4334,10 @@ static struct attribute *slab_attrs[] = {
         &deactivate_remote_frees_attr.attr,
         &order_fallback_attr.attr,
 #endif
+#ifdef CONFIG_FAILSLAB
+        &failslab_attr.attr,
+#endif
+
         NULL
 };