Merge branch 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux

* 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux:
  tools, slub: Fix off-by-one buffer corruption after readlink() call
  slub: Discard slab page when node partial > minimum partial number
  slub: correct comments error for per cpu partial
  mm: restrict access to slab files under procfs and sysfs
  slub: Code optimization in get_partial_node()
  slub: doc: update the slabinfo.c file path
  slub: explicitly document position of inserting slab to partial list
  slub: update slabinfo tools to report per cpu partial list statistics
  slub: per cpu cache for partial pages
  slub: return object pointer from get_partial() / new_slab().
  slub: pass kmem_cache_cpu pointer to get_partial()
  slub: Prepare inuse field in new_slab()
  slub: Remove useless statements in __slab_alloc
  slub: free slabs without holding locks
  slub: use print_hex_dump
  slab: use print_hex_dump

6 files changed, 425 insertions, 182 deletions

diff --git a/Documentation/vm/00-INDEX b/Documentation/vm/00-INDEX
index dca82d7c83d8..5481c8ba3412 100644
--- a/Documentation/vm/00-INDEX
+++ b/Documentation/vm/00-INDEX
@@ -30,8 +30,6 @@ page_migration
         - description of page migration in NUMA systems.
 pagemap.txt
         - pagemap, from the userspace perspective
-slabinfo.c
-        - source code for a tool to get reports about slabs.
 slub.txt
         - a short users guide for SLUB.
 unevictable-lru.txt
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 29971a589ff2..c93d00a6e95d 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -79,9 +79,21 @@ struct page {
         };
 
         /* Third double word block */
-        struct list_head lru;           /* Pageout list, eg. active_list
+        union {
+                struct list_head lru;   /* Pageout list, eg. active_list
                                          * protected by zone->lru_lock !
                                          */
+                struct {                /* slub per cpu partial pages */
+                        struct page *next;      /* Next partial slab */
+#ifdef CONFIG_64BIT
+                        int pages;      /* Nr of partial slabs left */
+                        int pobjects;   /* Approximate # of objects */
+#else
+                        short int pages;
+                        short int pobjects;
+#endif
+                };
+        };
 
         /* Remainder is not double word aligned */
         union {
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index f58d6413d230..a32bcfdc7834 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -36,12 +36,15 @@ enum stat_item {
         ORDER_FALLBACK,         /* Number of times fallback was necessary */
         CMPXCHG_DOUBLE_CPU_FAIL,/* Failure of this_cpu_cmpxchg_double */
         CMPXCHG_DOUBLE_FAIL,    /* Number of times that cmpxchg double did not match */
+        CPU_PARTIAL_ALLOC,      /* Used cpu partial on alloc */
+        CPU_PARTIAL_FREE,       /* USed cpu partial on free */
         NR_SLUB_STAT_ITEMS };
 
 struct kmem_cache_cpu {
         void **freelist;        /* Pointer to next available object */
         unsigned long tid;      /* Globally unique transaction id */
         struct page *page;      /* The slab from which we are allocating */
+        struct page *partial;   /* Partially allocated frozen slabs */
         int node;               /* The node of the page (or -1 for debug) */
 #ifdef CONFIG_SLUB_STATS
         unsigned stat[NR_SLUB_STAT_ITEMS];
@@ -79,6 +82,7 @@ struct kmem_cache {
         int size;               /* The size of an object including meta data */
         int objsize;            /* The size of an object without meta data */
         int offset;             /* Free pointer offset. */
+        int cpu_partial;        /* Number of per cpu partial objects to keep around */
         struct kmem_cache_order_objects oo;
 
         /* Allocation and freeing of slabs */
diff --git a/mm/slab.c b/mm/slab.c
index 6d90a091fdca..708efe886154 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1851,15 +1851,15 @@ static void dump_line(char *data, int offset, int limit)
         unsigned char error = 0;
         int bad_count = 0;
 
-        printk(KERN_ERR "%03x:", offset);
+        printk(KERN_ERR "%03x: ", offset);
         for (i = 0; i < limit; i++) {
                 if (data[offset + i] != POISON_FREE) {
                         error = data[offset + i];
                         bad_count++;
                 }
-                printk(" %02x", (unsigned char)data[offset + i]);
         }
-        printk("\n");
+        print_hex_dump(KERN_CONT, "", 0, 16, 1,
+                        &data[offset], limit, 1);
 
         if (bad_count == 1) {
                 error ^= POISON_FREE;
@@ -3039,14 +3039,9 @@ bad:
                 printk(KERN_ERR "slab: Internal list corruption detected in "
                                 "cache '%s'(%d), slabp %p(%d). Hexdump:\n",
                         cachep->name, cachep->num, slabp, slabp->inuse);
-                for (i = 0;
-                     i < sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t);
-                     i++) {
-                        if (i % 16 == 0)
-                                printk("\n%03x:", i);
-                        printk(" %02x", ((unsigned char *)slabp)[i]);
-                }
-                printk("\n");
+                print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1, slabp,
+                        sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t),
+                        1);
                 BUG();
         }
 }
@@ -4584,7 +4579,7 @@ static const struct file_operations proc_slabstats_operations = {
 
 static int __init slab_proc_init(void)
 {
-        proc_create("slabinfo",S_IWUSR|S_IRUGO,NULL,&proc_slabinfo_operations);
+        proc_create("slabinfo",S_IWUSR|S_IRUSR,NULL,&proc_slabinfo_operations);
 #ifdef CONFIG_DEBUG_SLAB_LEAK
         proc_create("slab_allocators", 0, NULL, &proc_slabstats_operations);
 #endif
diff --git a/mm/slub.c b/mm/slub.c
index 7c54fe83a90c..95215aa6a75e 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -467,34 +467,8 @@ static int disable_higher_order_debug;
  */
 static void print_section(char *text, u8 *addr, unsigned int length)
 {
-        int i, offset;
-        int newline = 1;
-        char ascii[17];
-
-        ascii[16] = 0;
-
-        for (i = 0; i < length; i++) {
-                if (newline) {
-                        printk(KERN_ERR "%8s 0x%p: ", text, addr + i);
-                        newline = 0;
-                }
-                printk(KERN_CONT " %02x", addr[i]);
-                offset = i % 16;
-                ascii[offset] = isgraph(addr[i]) ? addr[i] : '.';
-                if (offset == 15) {
-                        printk(KERN_CONT " %s\n", ascii);
-                        newline = 1;
-                }
-        }
-        if (!newline) {
-                i %= 16;
-                while (i < 16) {
-                        printk(KERN_CONT "   ");
-                        ascii[i] = ' ';
-                        i++;
-                }
-                printk(KERN_CONT " %s\n", ascii);
-        }
+        print_hex_dump(KERN_ERR, text, DUMP_PREFIX_ADDRESS, 16, 1, addr,
+                        length, 1);
 }
 
 static struct track *get_track(struct kmem_cache *s, void *object,
@@ -625,12 +599,12 @@ static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p)
                         p, p - addr, get_freepointer(s, p));
 
         if (p > addr + 16)
-                print_section("Bytes b4", p - 16, 16);
-
-        print_section("Object", p, min_t(unsigned long, s->objsize, PAGE_SIZE));
+                print_section("Bytes b4 ", p - 16, 16);
 
+        print_section("Object ", p, min_t(unsigned long, s->objsize,
+                                PAGE_SIZE));
         if (s->flags & SLAB_RED_ZONE)
-                print_section("Redzone", p + s->objsize,
+                print_section("Redzone ", p + s->objsize,
                         s->inuse - s->objsize);
 
         if (s->offset)
@@ -643,7 +617,7 @@ static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p)
 
         if (off != s->size)
                 /* Beginning of the filler is the free pointer */
-                print_section("Padding", p + off, s->size - off);
+                print_section("Padding ", p + off, s->size - off);
 
         dump_stack();
 }
@@ -838,7 +812,7 @@ static int slab_pad_check(struct kmem_cache *s, struct page *page)
                 end--;
 
         slab_err(s, page, "Padding overwritten. 0x%p-0x%p", fault, end - 1);
-        print_section("Padding", end - remainder, remainder);
+        print_section("Padding ", end - remainder, remainder);
 
         restore_bytes(s, "slab padding", POISON_INUSE, end - remainder, end);
         return 0;
@@ -987,7 +961,7 @@ static void trace(struct kmem_cache *s, struct page *page, void *object,
                         page->freelist);
 
                 if (!alloc)
-                        print_section("Object", (void *)object, s->objsize);
+                        print_section("Object ", (void *)object, s->objsize);
 
                 dump_stack();
         }
@@ -1447,7 +1421,7 @@ static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
         set_freepointer(s, last, NULL);
 
         page->freelist = start;
-        page->inuse = 0;
+        page->inuse = page->objects;
         page->frozen = 1;
 out:
         return page;
@@ -1534,7 +1508,7 @@ static inline void add_partial(struct kmem_cache_node *n,
                                 struct page *page, int tail)
 {
         n->nr_partial++;
-        if (tail)
+        if (tail == DEACTIVATE_TO_TAIL)
                 list_add_tail(&page->lru, &n->partial);
         else
                 list_add(&page->lru, &n->partial);
@@ -1554,10 +1528,13 @@ static inline void remove_partial(struct kmem_cache_node *n,
  * Lock slab, remove from the partial list and put the object into the
  * per cpu freelist.
  *
+ * Returns a list of objects or NULL if it fails.
+ *
  * Must hold list_lock.
  */
-static inline int acquire_slab(struct kmem_cache *s,
-                struct kmem_cache_node *n, struct page *page)
+static inline void *acquire_slab(struct kmem_cache *s,
+                struct kmem_cache_node *n, struct page *page,
+                int mode)
 {
         void *freelist;
         unsigned long counters;
@@ -1572,7 +1549,8 @@ static inline int acquire_slab(struct kmem_cache *s,
                 freelist = page->freelist;
                 counters = page->counters;
                 new.counters = counters;
-                new.inuse = page->objects;
+                if (mode)
+                        new.inuse = page->objects;
 
                 VM_BUG_ON(new.frozen);
                 new.frozen = 1;
@@ -1583,32 +1561,19 @@ static inline int acquire_slab(struct kmem_cache *s,
                         "lock and freeze"));
 
         remove_partial(n, page);
-
-        if (freelist) {
-                /* Populate the per cpu freelist */
-                this_cpu_write(s->cpu_slab->freelist, freelist);
-                this_cpu_write(s->cpu_slab->page, page);
-                this_cpu_write(s->cpu_slab->node, page_to_nid(page));
-                return 1;
-        } else {
-                /*
-                 * Slab page came from the wrong list. No object to allocate
-                 * from. Put it onto the correct list and continue partial
-                 * scan.
-                 */
-                printk(KERN_ERR "SLUB: %s : Page without available objects on"
-                        " partial list\n", s->name);
-                return 0;
-        }
+        return freelist;
 }
 
+static int put_cpu_partial(struct kmem_cache *s, struct page *page, int drain);
+
 /*
  * Try to allocate a partial slab from a specific node.
  */
-static struct page *get_partial_node(struct kmem_cache *s,
-                                        struct kmem_cache_node *n)
+static void *get_partial_node(struct kmem_cache *s,
+                struct kmem_cache_node *n, struct kmem_cache_cpu *c)
 {
-        struct page *page;
+        struct page *page, *page2;
+        void *object = NULL;
 
         /*
          * Racy check. If we mistakenly see no partial slabs then we
@@ -1620,26 +1585,43 @@ static struct page *get_partial_node(struct kmem_cache *s,
                 return NULL;
 
         spin_lock(&n->list_lock);
-        list_for_each_entry(page, &n->partial, lru)
-                if (acquire_slab(s, n, page))
-                        goto out;
-        page = NULL;
-out:
+        list_for_each_entry_safe(page, page2, &n->partial, lru) {
+                void *t = acquire_slab(s, n, page, object == NULL);
+                int available;
+
+                if (!t)
+                        break;
+
+                if (!object) {
+                        c->page = page;
+                        c->node = page_to_nid(page);
+                        stat(s, ALLOC_FROM_PARTIAL);
+                        object = t;
+                        available =  page->objects - page->inuse;
+                } else {
+                        page->freelist = t;
+                        available = put_cpu_partial(s, page, 0);
+                }
+                if (kmem_cache_debug(s) || available > s->cpu_partial / 2)
+                        break;
+
+        }
         spin_unlock(&n->list_lock);
-        return page;
+        return object;
 }
 
 /*
  * Get a page from somewhere. Search in increasing NUMA distances.
  */
-static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags)
+static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags,
+                struct kmem_cache_cpu *c)
 {
 #ifdef CONFIG_NUMA
         struct zonelist *zonelist;
         struct zoneref *z;
         struct zone *zone;
         enum zone_type high_zoneidx = gfp_zone(flags);
-        struct page *page;
+        void *object;
 
         /*
          * The defrag ratio allows a configuration of the tradeoffs between
@@ -1672,10 +1654,10 @@ static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags)
 
                 if (n && cpuset_zone_allowed_hardwall(zone, flags) &&
                                 n->nr_partial > s->min_partial) {
-                        page = get_partial_node(s, n);
-                        if (page) {
+                        object = get_partial_node(s, n, c);
+                        if (object) {
                                 put_mems_allowed();
-                                return page;
+                                return object;
                         }
                 }
         }
@@ -1687,16 +1669,17 @@ static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags)
 /*
  * Get a partial page, lock it and return it.
  */
-static struct page *get_partial(struct kmem_cache *s, gfp_t flags, int node)
+static void *get_partial(struct kmem_cache *s, gfp_t flags, int node,
+                struct kmem_cache_cpu *c)
 {
-        struct page *page;
+        void *object;
         int searchnode = (node == NUMA_NO_NODE) ? numa_node_id() : node;
 
-        page = get_partial_node(s, get_node(s, searchnode));
-        if (page || node != NUMA_NO_NODE)
-                return page;
+        object = get_partial_node(s, get_node(s, searchnode), c);
+        if (object || node != NUMA_NO_NODE)
+                return object;
 
-        return get_any_partial(s, flags);
+        return get_any_partial(s, flags, c);
 }
 
 #ifdef CONFIG_PREEMPT
@@ -1765,9 +1748,6 @@ void init_kmem_cache_cpus(struct kmem_cache *s)
         for_each_possible_cpu(cpu)
                 per_cpu_ptr(s->cpu_slab, cpu)->tid = init_tid(cpu);
 }
-/*
- * Remove the cpu slab
- */
 
 /*
  * Remove the cpu slab
@@ -1781,13 +1761,13 @@ static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
         enum slab_modes l = M_NONE, m = M_NONE;
         void *freelist;
         void *nextfree;
-        int tail = 0;
+        int tail = DEACTIVATE_TO_HEAD;
         struct page new;
         struct page old;
 
         if (page->freelist) {
                 stat(s, DEACTIVATE_REMOTE_FREES);
-                tail = 1;
+                tail = DEACTIVATE_TO_TAIL;
         }
 
         c->tid = next_tid(c->tid);
@@ -1893,7 +1873,7 @@ redo:
                 if (m == M_PARTIAL) {
 
                         add_partial(n, page, tail);
-                        stat(s, tail ? DEACTIVATE_TO_TAIL : DEACTIVATE_TO_HEAD);
+                        stat(s, tail);
 
                 } else if (m == M_FULL) {
 
@@ -1920,6 +1900,123 @@ redo:
         }
 }
 
+/* Unfreeze all the cpu partial slabs */
+static void unfreeze_partials(struct kmem_cache *s)
+{
+        struct kmem_cache_node *n = NULL;
+        struct kmem_cache_cpu *c = this_cpu_ptr(s->cpu_slab);
+        struct page *page;
+
+        while ((page = c->partial)) {
+                enum slab_modes { M_PARTIAL, M_FREE };
+                enum slab_modes l, m;
+                struct page new;
+                struct page old;
+
+                c->partial = page->next;
+                l = M_FREE;
+
+                do {
+
+                        old.freelist = page->freelist;
+                        old.counters = page->counters;
+                        VM_BUG_ON(!old.frozen);
+
+                        new.counters = old.counters;
+                        new.freelist = old.freelist;
+
+                        new.frozen = 0;
+
+                        if (!new.inuse && (!n || n->nr_partial > s->min_partial))
+                                m = M_FREE;
+                        else {
+                                struct kmem_cache_node *n2 = get_node(s,
+                                                        page_to_nid(page));
+
+                                m = M_PARTIAL;
+                                if (n != n2) {
+                                        if (n)
+                                                spin_unlock(&n->list_lock);
+
+                                        n = n2;
+                                        spin_lock(&n->list_lock);
+                                }
+                        }
+
+                        if (l != m) {
+                                if (l == M_PARTIAL)
+                                        remove_partial(n, page);
+                                else
+                                        add_partial(n, page, 1);
+
+                                l = m;
+                        }
+
+                } while (!cmpxchg_double_slab(s, page,
+                                old.freelist, old.counters,
+                                new.freelist, new.counters,
+                                "unfreezing slab"));
+
+                if (m == M_FREE) {
+                        stat(s, DEACTIVATE_EMPTY);
+                        discard_slab(s, page);
+                        stat(s, FREE_SLAB);
+                }
+        }
+
+        if (n)
+                spin_unlock(&n->list_lock);
+}
+
+/*
+ * Put a page that was just frozen (in __slab_free) into a partial page
+ * slot if available. This is done without interrupts disabled and without
+ * preemption disabled. The cmpxchg is racy and may put the partial page
+ * onto a random cpus partial slot.
+ *
+ * If we did not find a slot then simply move all the partials to the
+ * per node partial list.
+ */
+int put_cpu_partial(struct kmem_cache *s, struct page *page, int drain)
+{
+        struct page *oldpage;
+        int pages;
+        int pobjects;
+
+        do {
+                pages = 0;
+                pobjects = 0;
+                oldpage = this_cpu_read(s->cpu_slab->partial);
+
+                if (oldpage) {
+                        pobjects = oldpage->pobjects;
+                        pages = oldpage->pages;
+                        if (drain && pobjects > s->cpu_partial) {
+                                unsigned long flags;
+                                /*
+                                 * partial array is full. Move the existing
+                                 * set to the per node partial list.
+                                 */
+                                local_irq_save(flags);
+                                unfreeze_partials(s);
+                                local_irq_restore(flags);
+                                pobjects = 0;
+                                pages = 0;
+                        }
+                }
+
+                pages++;
+                pobjects += page->objects - page->inuse;
+
+                page->pages = pages;
+                page->pobjects = pobjects;
+                page->next = oldpage;
+
+        } while (this_cpu_cmpxchg(s->cpu_slab->partial, oldpage, page) != oldpage);
+        stat(s, CPU_PARTIAL_FREE);
+        return pobjects;
+}
+
 static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
 {
         stat(s, CPUSLAB_FLUSH);
@@ -1935,8 +2032,12 @@ static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu)
 {
         struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
 
-        if (likely(c && c->page))
-                flush_slab(s, c);
+        if (likely(c)) {
+                if (c->page)
+                        flush_slab(s, c);
+
+                unfreeze_partials(s);
+        }
 }
 
 static void flush_cpu_slab(void *d)
@@ -2027,12 +2128,39 @@ slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid)
         }
 }
 
+static inline void *new_slab_objects(struct kmem_cache *s, gfp_t flags,
+                        int node, struct kmem_cache_cpu **pc)
+{
+        void *object;
+        struct kmem_cache_cpu *c;
+        struct page *page = new_slab(s, flags, node);
+
+        if (page) {
+                c = __this_cpu_ptr(s->cpu_slab);
+                if (c->page)
+                        flush_slab(s, c);
+
+                /*
+                 * No other reference to the page yet so we can
+                 * muck around with it freely without cmpxchg
+                 */
+                object = page->freelist;
+                page->freelist = NULL;
+
+                stat(s, ALLOC_SLAB);
+                c->node = page_to_nid(page);
+                c->page = page;
+                *pc = c;
+        } else
+                object = NULL;
+
+        return object;
+}
+
 /*
  * Slow path. The lockless freelist is empty or we need to perform
  * debugging duties.
  *
- * Interrupts are disabled.
- *
  * Processing is still very fast if new objects have been freed to the
  * regular freelist. In that case we simply take over the regular freelist
  * as the lockless freelist and zap the regular freelist.
@@ -2049,7 +2177,6 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
                           unsigned long addr, struct kmem_cache_cpu *c)
 {
         void **object;
-        struct page *page;
         unsigned long flags;
         struct page new;
         unsigned long counters;
@@ -2064,13 +2191,9 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
         c = this_cpu_ptr(s->cpu_slab);
 #endif
 
-        /* We handle __GFP_ZERO in the caller */
-        gfpflags &= ~__GFP_ZERO;
-
-        page = c->page;
-        if (!page)
+        if (!c->page)
                 goto new_slab;
-
+redo:
         if (unlikely(!node_match(c, node))) {
                 stat(s, ALLOC_NODE_MISMATCH);
                 deactivate_slab(s, c);
@@ -2080,8 +2203,8 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
         stat(s, ALLOC_SLOWPATH);
 
         do {
-                object = page->freelist;
-                counters = page->counters;
+                object = c->page->freelist;
+                counters = c->page->counters;
                 new.counters = counters;
                 VM_BUG_ON(!new.frozen);
 
@@ -2093,17 +2216,17 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
                  *
                  * If there are objects left then we retrieve them
                  * and use them to refill the per cpu queue.
-                */
+                 */
 
-                new.inuse = page->objects;
+                new.inuse = c->page->objects;
                 new.frozen = object != NULL;
 
-        } while (!__cmpxchg_double_slab(s, page,
+        } while (!__cmpxchg_double_slab(s, c->page,
                         object, counters,
                         NULL, new.counters,
                         "__slab_alloc"));
 
-        if (unlikely(!object)) {
+        if (!object) {
                 c->page = NULL;
                 stat(s, DEACTIVATE_BYPASS);
                 goto new_slab;
@@ -2112,58 +2235,47 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
         stat(s, ALLOC_REFILL);
 
 load_freelist:
-        VM_BUG_ON(!page->frozen);
         c->freelist = get_freepointer(s, object);
         c->tid = next_tid(c->tid);
         local_irq_restore(flags);
         return object;
 
 new_slab:
-        page = get_partial(s, gfpflags, node);
-        if (page) {
-                stat(s, ALLOC_FROM_PARTIAL);
-                object = c->freelist;
 
-                if (kmem_cache_debug(s))
-                        goto debug;
-                goto load_freelist;
+        if (c->partial) {
+                c->page = c->partial;
+                c->partial = c->page->next;
+                c->node = page_to_nid(c->page);
+                stat(s, CPU_PARTIAL_ALLOC);
+                c->freelist = NULL;
+                goto redo;
         }
 
-        page = new_slab(s, gfpflags, node);
+        /* Then do expensive stuff like retrieving pages from the partial lists */
+        object = get_partial(s, gfpflags, node, c);
 
-        if (page) {
-                c = __this_cpu_ptr(s->cpu_slab);
-                if (c->page)
-                        flush_slab(s, c);
+        if (unlikely(!object)) {
 
-                /*
-                 * No other reference to the page yet so we can
-                 * muck around with it freely without cmpxchg
-                 */
-                object = page->freelist;
-                page->freelist = NULL;
-                page->inuse = page->objects;
+                object = new_slab_objects(s, gfpflags, node, &c);
 
-                stat(s, ALLOC_SLAB);
-                c->node = page_to_nid(page);
-                c->page = page;
+                if (unlikely(!object)) {
+                        if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
+                                slab_out_of_memory(s, gfpflags, node);
 
-                if (kmem_cache_debug(s))
-                        goto debug;
-                goto load_freelist;
+                        local_irq_restore(flags);
+                        return NULL;
+                }
         }
-        if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
-                slab_out_of_memory(s, gfpflags, node);
-        local_irq_restore(flags);
-        return NULL;
 
-debug:
-        if (!object || !alloc_debug_processing(s, page, object, addr))
-                goto new_slab;
+        if (likely(!kmem_cache_debug(s)))
+                goto load_freelist;
+
+        /* Only entered in the debug case */
+        if (!alloc_debug_processing(s, c->page, object, addr))
+                goto new_slab;  /* Slab failed checks. Next slab needed */
 
         c->freelist = get_freepointer(s, object);
         deactivate_slab(s, c);
-        c->page = NULL;
         c->node = NUMA_NO_NODE;
         local_irq_restore(flags);
         return object;
@@ -2333,16 +2445,29 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
                 was_frozen = new.frozen;
                 new.inuse--;
                 if ((!new.inuse || !prior) && !was_frozen && !n) {
-                        n = get_node(s, page_to_nid(page));
-                        /*
-                         * Speculatively acquire the list_lock.
-                         * If the cmpxchg does not succeed then we may
-                         * drop the list_lock without any processing.
-                         *
-                         * Otherwise the list_lock will synchronize with
-                         * other processors updating the list of slabs.
-                         */
-                        spin_lock_irqsave(&n->list_lock, flags);
+
+                        if (!kmem_cache_debug(s) && !prior)
+
+                                /*
+                                 * Slab was on no list before and will be partially empty
+                                 * We can defer the list move and instead freeze it.
+                                 */
+                                new.frozen = 1;
+
+                        else { /* Needs to be taken off a list */
+
+                                n = get_node(s, page_to_nid(page));
+                                /*
+                                 * Speculatively acquire the list_lock.
+                                 * If the cmpxchg does not succeed then we may
+                                 * drop the list_lock without any processing.
+                                 *
+                                 * Otherwise the list_lock will synchronize with
+                                 * other processors updating the list of slabs.
+                                 */
+                                spin_lock_irqsave(&n->list_lock, flags);
+
+                        }
                 }
                 inuse = new.inuse;
 
@@ -2352,7 +2477,15 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
                 "__slab_free"));
 
         if (likely(!n)) {
-                /*
+
+                /*
+                 * If we just froze the page then put it onto the
+                 * per cpu partial list.
+                 */
+                if (new.frozen && !was_frozen)
+                        put_cpu_partial(s, page, 1);
+
+                /*
                  * The list lock was not taken therefore no list
                  * activity can be necessary.
                  */
@@ -2377,7 +2510,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
                  */
                 if (unlikely(!prior)) {
                         remove_full(s, page);
-                        add_partial(n, page, 1);
+                        add_partial(n, page, DEACTIVATE_TO_TAIL);
                         stat(s, FREE_ADD_PARTIAL);
                 }
         }
@@ -2421,7 +2554,6 @@ static __always_inline void slab_free(struct kmem_cache *s,
         slab_free_hook(s, x);
 
 redo:
-
         /*
          * Determine the currently cpus per cpu slab.
          * The cpu may change afterward. However that does not matter since
@@ -2685,7 +2817,7 @@ static void early_kmem_cache_node_alloc(int node)
         n = page->freelist;
         BUG_ON(!n);
         page->freelist = get_freepointer(kmem_cache_node, n);
-        page->inuse++;
+        page->inuse = 1;
         page->frozen = 0;
         kmem_cache_node->node[node] = n;
 #ifdef CONFIG_SLUB_DEBUG
@@ -2695,7 +2827,7 @@ static void early_kmem_cache_node_alloc(int node)
         init_kmem_cache_node(n, kmem_cache_node);
         inc_slabs_node(kmem_cache_node, node, page->objects);
 
-        add_partial(n, page, 0);
+        add_partial(n, page, DEACTIVATE_TO_HEAD);
 }
 
 static void free_kmem_cache_nodes(struct kmem_cache *s)
@@ -2911,7 +3043,34 @@ static int kmem_cache_open(struct kmem_cache *s,
          * The larger the object size is, the more pages we want on the partial
          * list to avoid pounding the page allocator excessively.
          */
-        set_min_partial(s, ilog2(s->size));
+        set_min_partial(s, ilog2(s->size) / 2);
+
+        /*
+         * cpu_partial determined the maximum number of objects kept in the
+         * per cpu partial lists of a processor.
+         *
+         * Per cpu partial lists mainly contain slabs that just have one
+         * object freed. If they are used for allocation then they can be
+         * filled up again with minimal effort. The slab will never hit the
+         * per node partial lists and therefore no locking will be required.
+         *
+         * This setting also determines
+         *
+         * A) The number of objects from per cpu partial slabs dumped to the
+         *    per node list when we reach the limit.
+         * B) The number of objects in cpu partial slabs to extract from the
+         *    per node list when we run out of per cpu objects. We only fetch 50%
+         *    to keep some capacity around for frees.
+         */
+        if (s->size >= PAGE_SIZE)
+                s->cpu_partial = 2;
+        else if (s->size >= 1024)
+                s->cpu_partial = 6;
+        else if (s->size >= 256)
+                s->cpu_partial = 13;
+        else
+                s->cpu_partial = 30;
+
         s->refcount = 1;
 #ifdef CONFIG_NUMA
         s->remote_node_defrag_ratio = 1000;
@@ -2970,13 +3129,13 @@ static void list_slab_objects(struct kmem_cache *s, struct page *page,
 
 /*
  * Attempt to free all partial slabs on a node.
+ * This is called from kmem_cache_close(). We must be the last thread
+ * using the cache and therefore we do not need to lock anymore.
  */
 static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n)
 {
-        unsigned long flags;
         struct page *page, *h;
 
-        spin_lock_irqsave(&n->list_lock, flags);
         list_for_each_entry_safe(page, h, &n->partial, lru) {
                 if (!page->inuse) {
                         remove_partial(n, page);
@@ -2986,7 +3145,6 @@ static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n)
                                 "Objects remaining on kmem_cache_close()");
                 }
         }
-        spin_unlock_irqrestore(&n->list_lock, flags);
 }
 
 /*
@@ -3020,6 +3178,7 @@ void kmem_cache_destroy(struct kmem_cache *s)
         s->refcount--;
         if (!s->refcount) {
                 list_del(&s->list);
+                up_write(&slub_lock);
                 if (kmem_cache_close(s)) {
                         printk(KERN_ERR "SLUB %s: %s called for cache that "
                                 "still has objects.\n", s->name, __func__);
@@ -3028,8 +3187,8 @@ void kmem_cache_destroy(struct kmem_cache *s)
                 if (s->flags & SLAB_DESTROY_BY_RCU)
                         rcu_barrier();
                 sysfs_slab_remove(s);
-        }
-        up_write(&slub_lock);
+        } else
+                up_write(&slub_lock);
 }
 EXPORT_SYMBOL(kmem_cache_destroy);
 
@@ -3347,23 +3506,23 @@ int kmem_cache_shrink(struct kmem_cache *s)
                  * list_lock. page->inuse here is the upper limit.
                  */
                 list_for_each_entry_safe(page, t, &n->partial, lru) {
-                        if (!page->inuse) {
-                                remove_partial(n, page);
-                                discard_slab(s, page);
-                        } else {
-                                list_move(&page->lru,
-                                slabs_by_inuse + page->inuse);
-                        }
+                        list_move(&page->lru, slabs_by_inuse + page->inuse);
+                        if (!page->inuse)
+                                n->nr_partial--;
                 }
 
                 /*
                  * Rebuild the partial list with the slabs filled up most
                  * first and the least used slabs at the end.
                  */
-                for (i = objects - 1; i >= 0; i--)
+                for (i = objects - 1; i > 0; i--)
                         list_splice(slabs_by_inuse + i, n->partial.prev);
 
                 spin_unlock_irqrestore(&n->list_lock, flags);
+
+                /* Release empty slabs */
+                list_for_each_entry_safe(page, t, slabs_by_inuse, lru)
+                        discard_slab(s, page);
         }
 
         kfree(slabs_by_inuse);
@@ -4319,6 +4478,7 @@ static ssize_t show_slab_objects(struct kmem_cache *s,
 
                 for_each_possible_cpu(cpu) {
                         struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
+                        struct page *page;
 
                         if (!c || c->node < 0)
                                 continue;
@@ -4334,6 +4494,13 @@ static ssize_t show_slab_objects(struct kmem_cache *s,
                                 total += x;
                                 nodes[c->node] += x;
                         }
+                        page = c->partial;
+
+                        if (page) {
+                                x = page->pobjects;
+                                total += x;
+                                nodes[c->node] += x;
+                        }
                         per_cpu[c->node]++;
                 }
         }
@@ -4412,11 +4579,12 @@ struct slab_attribute {
 };
 
 #define SLAB_ATTR_RO(_name) \
-        static struct slab_attribute _name##_attr = __ATTR_RO(_name)
+        static struct slab_attribute _name##_attr = \
+        __ATTR(_name, 0400, _name##_show, NULL)
 
 #define SLAB_ATTR(_name) \
         static struct slab_attribute _name##_attr =  \
-        __ATTR(_name, 0644, _name##_show, _name##_store)
+        __ATTR(_name, 0600, _name##_show, _name##_store)
 
 static ssize_t slab_size_show(struct kmem_cache *s, char *buf)
 {
@@ -4485,6 +4653,27 @@ static ssize_t min_partial_store(struct kmem_cache *s, const char *buf,
 }
 SLAB_ATTR(min_partial);
 
+static ssize_t cpu_partial_show(struct kmem_cache *s, char *buf)
+{
+        return sprintf(buf, "%u\n", s->cpu_partial);
+}
+
+static ssize_t cpu_partial_store(struct kmem_cache *s, const char *buf,
+                                 size_t length)
+{
+        unsigned long objects;
+        int err;
+
+        err = strict_strtoul(buf, 10, &objects);
+        if (err)
+                return err;
+
+        s->cpu_partial = objects;
+        flush_all(s);
+        return length;
+}
+SLAB_ATTR(cpu_partial);
+
 static ssize_t ctor_show(struct kmem_cache *s, char *buf)
 {
         if (!s->ctor)
@@ -4523,6 +4712,37 @@ static ssize_t objects_partial_show(struct kmem_cache *s, char *buf)
 }
 SLAB_ATTR_RO(objects_partial);
 
+static ssize_t slabs_cpu_partial_show(struct kmem_cache *s, char *buf)
+{
+        int objects = 0;
+        int pages = 0;
+        int cpu;
+        int len;
+
+        for_each_online_cpu(cpu) {
+                struct page *page = per_cpu_ptr(s->cpu_slab, cpu)->partial;
+
+                if (page) {
+                        pages += page->pages;
+                        objects += page->pobjects;
+                }
+        }
+
+        len = sprintf(buf, "%d(%d)", objects, pages);
+
+#ifdef CONFIG_SMP
+        for_each_online_cpu(cpu) {
+                struct page *page = per_cpu_ptr(s->cpu_slab, cpu) ->partial;
+
+                if (page && len < PAGE_SIZE - 20)
+                        len += sprintf(buf + len, " C%d=%d(%d)", cpu,
+                                page->pobjects, page->pages);
+        }
+#endif
+        return len + sprintf(buf + len, "\n");
+}
+SLAB_ATTR_RO(slabs_cpu_partial);
+
 static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf)
 {
         return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT));
@@ -4845,6 +5065,8 @@ STAT_ATTR(DEACTIVATE_BYPASS, deactivate_bypass);
 STAT_ATTR(ORDER_FALLBACK, order_fallback);
 STAT_ATTR(CMPXCHG_DOUBLE_CPU_FAIL, cmpxchg_double_cpu_fail);
 STAT_ATTR(CMPXCHG_DOUBLE_FAIL, cmpxchg_double_fail);
+STAT_ATTR(CPU_PARTIAL_ALLOC, cpu_partial_alloc);
+STAT_ATTR(CPU_PARTIAL_FREE, cpu_partial_free);
 #endif
 
 static struct attribute *slab_attrs[] = {
@@ -4853,6 +5075,7 @@ static struct attribute *slab_attrs[] = {
         &objs_per_slab_attr.attr,
         &order_attr.attr,
         &min_partial_attr.attr,
+        &cpu_partial_attr.attr,
         &objects_attr.attr,
         &objects_partial_attr.attr,
         &partial_attr.attr,
@@ -4865,6 +5088,7 @@ static struct attribute *slab_attrs[] = {
         &destroy_by_rcu_attr.attr,
         &shrink_attr.attr,
         &reserved_attr.attr,
+        &slabs_cpu_partial_attr.attr,
 #ifdef CONFIG_SLUB_DEBUG
         &total_objects_attr.attr,
         &slabs_attr.attr,
@@ -4906,6 +5130,8 @@ static struct attribute *slab_attrs[] = {
         &order_fallback_attr.attr,
         &cmpxchg_double_fail_attr.attr,
         &cmpxchg_double_cpu_fail_attr.attr,
+        &cpu_partial_alloc_attr.attr,
+        &cpu_partial_free_attr.attr,
 #endif
 #ifdef CONFIG_FAILSLAB
         &failslab_attr.attr,
@@ -5257,7 +5483,7 @@ static const struct file_operations proc_slabinfo_operations = {
 
 static int __init slab_proc_init(void)
 {
-        proc_create("slabinfo", S_IRUGO, NULL, &proc_slabinfo_operations);
+        proc_create("slabinfo", S_IRUSR, NULL, &proc_slabinfo_operations);
         return 0;
 }
 module_init(slab_proc_init);
diff --git a/tools/slub/slabinfo.c b/tools/slub/slabinfo.c
index 868cc93f7ac2..164cbcf61106 100644
--- a/tools/slub/slabinfo.c
+++ b/tools/slub/slabinfo.c
@@ -42,6 +42,7 @@ struct slabinfo {
         unsigned long deactivate_remote_frees, order_fallback;
         unsigned long cmpxchg_double_cpu_fail, cmpxchg_double_fail;
         unsigned long alloc_node_mismatch, deactivate_bypass;
+        unsigned long cpu_partial_alloc, cpu_partial_free;
         int numa[MAX_NODES];
         int numa_partial[MAX_NODES];
 } slabinfo[MAX_SLABS];
@@ -455,6 +456,11 @@ static void slab_stats(struct slabinfo *s)
                 s->alloc_from_partial * 100 / total_alloc,
                 s->free_remove_partial * 100 / total_free);
 
+        printf("Cpu partial list     %8lu %8lu %3lu %3lu\n",
+                s->cpu_partial_alloc, s->cpu_partial_free,
+                s->cpu_partial_alloc * 100 / total_alloc,
+                s->cpu_partial_free * 100 / total_free);
+
         printf("RemoteObj/SlabFrozen %8lu %8lu %3lu %3lu\n",
                 s->deactivate_remote_frees, s->free_frozen,
                 s->deactivate_remote_frees * 100 / total_alloc,
@@ -1145,7 +1151,7 @@ static void read_slab_dir(void)
                 switch (de->d_type) {
                    case DT_LNK:
                         alias->name = strdup(de->d_name);
-                        count = readlink(de->d_name, buffer, sizeof(buffer));
+                        count = readlink(de->d_name, buffer, sizeof(buffer)-1);
 
                         if (count < 0)
                                 fatal("Cannot read symlink %s\n", de->d_name);
@@ -1209,6 +1215,8 @@ static void read_slab_dir(void)
                         slab->order_fallback = get_obj("order_fallback");
                         slab->cmpxchg_double_cpu_fail = get_obj("cmpxchg_double_cpu_fail");
                         slab->cmpxchg_double_fail = get_obj("cmpxchg_double_fail");
+                        slab->cpu_partial_alloc = get_obj("cpu_partial_alloc");
+                        slab->cpu_partial_free = get_obj("cpu_partial_free");
                         slab->alloc_node_mismatch = get_obj("alloc_node_mismatch");
                         slab->deactivate_bypass = get_obj("deactivate_bypass");
                         chdir("..");