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

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  slub: Deal with hyperthetical case of PAGE_SIZE > 2M
  slub: Remove node check in slab_free
  slub: avoid label inside conditional
  slub: Make CONFIG_DEBUG_PAGE_ALLOC work with new fastpath
  slub: Avoid warning for !CONFIG_SLUB_DEBUG
  slub: Remove CONFIG_CMPXCHG_LOCAL ifdeffery
  slub: Move debug handlign in __slab_free
  slub: Move node determination out of hotpath
  slub: Eliminate repeated use of c->page through a new page variable
  slub: get_map() function to establish map of free objects in a slab
  slub: Use NUMA_NO_NODE in get_partial
  slub: Fix a typo in config name

diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index 45ca123..c8668d1 100644 (file)
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -37,9 +37,7 @@ enum stat_item {
 
 struct kmem_cache_cpu {
        void **freelist;        /* Pointer to next available object */
-#ifdef CONFIG_CMPXCHG_LOCAL
        unsigned long tid;      /* Globally unique transaction id */
-#endif
        struct page *page;      /* The slab from which we are allocating */
        int node;               /* The node of the page (or -1 for debug) */
 #ifdef CONFIG_SLUB_STATS
@@ -179,7 +177,8 @@ static __always_inline int kmalloc_index(size_t size)
        if (size <=   4 * 1024) return 12;
 /*
  * The following is only needed to support architectures with a larger page
- * size than 4k.
+ * size than 4k. We need to support 2 * PAGE_SIZE here. So for a 64k page
+ * size we would have to go up to 128k.
  */
        if (size <=   8 * 1024) return 13;
        if (size <=  16 * 1024) return 14;
@@ -190,7 +189,8 @@ static __always_inline int kmalloc_index(size_t size)
        if (size <= 512 * 1024) return 19;
        if (size <= 1024 * 1024) return 20;
        if (size <=  2 * 1024 * 1024) return 21;
-       return -1;
+       BUG();
+       return -1; /* Will never be reached */
 
 /*
  * What we really wanted to do and cannot do because of compiler issues is:

diff --git a/mm/slub.c b/mm/slub.c
index 9d2e5e4..4ea7f1a 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -261,6 +261,18 @@ static inline void *get_freepointer(struct kmem_cache *s, void *object)
        return *(void **)(object + s->offset);
 }
 
+static inline void *get_freepointer_safe(struct kmem_cache *s, void *object)
+{
+       void *p;
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+       probe_kernel_read(&p, (void **)(object + s->offset), sizeof(p));
+#else
+       p = get_freepointer(s, object);
+#endif
+       return p;
+}
+
 static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
 {
        *(void **)(object + s->offset) = fp;
@@ -271,10 +283,6 @@ static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
        for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\
                        __p += (__s)->size)
 
-/* Scan freelist */
-#define for_each_free_object(__p, __s, __free) \
-       for (__p = (__free); __p; __p = get_freepointer((__s), __p))
-
 /* Determine object index from a given position */
 static inline int slab_index(void *p, struct kmem_cache *s, void *addr)
 {
@@ -331,6 +339,21 @@ static inline int oo_objects(struct kmem_cache_order_objects x)
 }
 
 #ifdef CONFIG_SLUB_DEBUG
+/*
+ * Determine a map of object in use on a page.
+ *
+ * Slab lock or node listlock must be held to guarantee that the page does
+ * not vanish from under us.
+ */
+static void get_map(struct kmem_cache *s, struct page *page, unsigned long *map)
+{
+       void *p;
+       void *addr = page_address(page);
+
+       for (p = page->freelist; p; p = get_freepointer(s, p))
+               set_bit(slab_index(p, s, addr), map);
+}
+
 /*
  * Debug settings:
  */
@@ -1487,7 +1510,7 @@ static struct page *get_partial(struct kmem_cache *s, gfp_t flags, int node)
        int searchnode = (node == NUMA_NO_NODE) ? numa_node_id() : node;
 
        page = get_partial_node(get_node(s, searchnode));
-       if (page || node != -1)
+       if (page || node != NUMA_NO_NODE)
                return page;
 
        return get_any_partial(s, flags);
@@ -1540,7 +1563,6 @@ static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail)
        }
 }
 
-#ifdef CONFIG_CMPXCHG_LOCAL
 #ifdef CONFIG_PREEMPT
 /*
  * Calculate the next globally unique transaction for disambiguiation
@@ -1600,17 +1622,12 @@ static inline void note_cmpxchg_failure(const char *n,
        stat(s, CMPXCHG_DOUBLE_CPU_FAIL);
 }
 
-#endif
-
 void init_kmem_cache_cpus(struct kmem_cache *s)
 {
-#ifdef CONFIG_CMPXCHG_LOCAL
        int cpu;
 
        for_each_possible_cpu(cpu)
                per_cpu_ptr(s->cpu_slab, cpu)->tid = init_tid(cpu);
-#endif
-
 }
 /*
  * Remove the cpu slab
@@ -1643,9 +1660,7 @@ static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
                page->inuse--;
        }
        c->page = NULL;
-#ifdef CONFIG_CMPXCHG_LOCAL
        c->tid = next_tid(c->tid);
-#endif
        unfreeze_slab(s, page, tail);
 }
 
@@ -1779,8 +1794,7 @@ 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 *new;
-#ifdef CONFIG_CMPXCHG_LOCAL
+       struct page *page;
        unsigned long flags;
 
        local_irq_save(flags);
@@ -1791,38 +1805,36 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
         * pointer.
         */
        c = this_cpu_ptr(s->cpu_slab);
-#endif
 #endif
 
        /* We handle __GFP_ZERO in the caller */
        gfpflags &= ~__GFP_ZERO;
 
-       if (!c->page)
+       page = c->page;
+       if (!page)
                goto new_slab;
 
-       slab_lock(c->page);
+       slab_lock(page);
        if (unlikely(!node_match(c, node)))
                goto another_slab;
 
        stat(s, ALLOC_REFILL);
 
 load_freelist:
-       object = c->page->freelist;
+       object = page->freelist;
        if (unlikely(!object))
                goto another_slab;
        if (kmem_cache_debug(s))
                goto debug;
 
        c->freelist = get_freepointer(s, object);
-       c->page->inuse = c->page->objects;
-       c->page->freelist = NULL;
-       c->node = page_to_nid(c->page);
+       page->inuse = page->objects;
+       page->freelist = NULL;
+
 unlock_out:
-       slab_unlock(c->page);
-#ifdef CONFIG_CMPXCHG_LOCAL
+       slab_unlock(page);
        c->tid = next_tid(c->tid);
        local_irq_restore(flags);
-#endif
        stat(s, ALLOC_SLOWPATH);
        return object;
 
@@ -1830,10 +1842,11 @@ another_slab:
        deactivate_slab(s, c);
 
 new_slab:
-       new = get_partial(s, gfpflags, node);
-       if (new) {
-               c->page = new;
+       page = get_partial(s, gfpflags, node);
+       if (page) {
                stat(s, ALLOC_FROM_PARTIAL);
+               c->node = page_to_nid(page);
+               c->page = page;
                goto load_freelist;
        }
 
@@ -1841,33 +1854,35 @@ new_slab:
        if (gfpflags & __GFP_WAIT)
                local_irq_enable();
 
-       new = new_slab(s, gfpflags, node);
+       page = new_slab(s, gfpflags, node);
 
        if (gfpflags & __GFP_WAIT)
                local_irq_disable();
 
-       if (new) {
+       if (page) {
                c = __this_cpu_ptr(s->cpu_slab);
                stat(s, ALLOC_SLAB);
                if (c->page)
                        flush_slab(s, c);
-               slab_lock(new);
-               __SetPageSlubFrozen(new);
-               c->page = new;
+
+               slab_lock(page);
+               __SetPageSlubFrozen(page);
+               c->node = page_to_nid(page);
+               c->page = page;
                goto load_freelist;
        }
        if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
                slab_out_of_memory(s, gfpflags, node);
-#ifdef CONFIG_CMPXCHG_LOCAL
        local_irq_restore(flags);
-#endif
        return NULL;
 debug:
-       if (!alloc_debug_processing(s, c->page, object, addr))
+       if (!alloc_debug_processing(s, page, object, addr))
                goto another_slab;
 
-       c->page->inuse++;
-       c->page->freelist = get_freepointer(s, object);
+       page->inuse++;
+       page->freelist = get_freepointer(s, object);
+       deactivate_slab(s, c);
+       c->page = NULL;
        c->node = NUMA_NO_NODE;
        goto unlock_out;
 }
@@ -1887,20 +1902,12 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
 {
        void **object;
        struct kmem_cache_cpu *c;
-#ifdef CONFIG_CMPXCHG_LOCAL
        unsigned long tid;
-#else
-       unsigned long flags;
-#endif
 
        if (slab_pre_alloc_hook(s, gfpflags))
                return NULL;
 
-#ifndef CONFIG_CMPXCHG_LOCAL
-       local_irq_save(flags);
-#else
 redo:
-#endif
 
        /*
         * Must read kmem_cache cpu data via this cpu ptr. Preemption is
@@ -1910,7 +1917,6 @@ redo:
         */
        c = __this_cpu_ptr(s->cpu_slab);
 
-#ifdef CONFIG_CMPXCHG_LOCAL
        /*
         * The transaction ids are globally unique per cpu and per operation on
         * a per cpu queue. Thus they can be guarantee that the cmpxchg_double
@@ -1919,7 +1925,6 @@ redo:
         */
        tid = c->tid;
        barrier();
-#endif
 
        object = c->freelist;
        if (unlikely(!object || !node_match(c, node)))
@@ -1927,7 +1932,6 @@ redo:
                object = __slab_alloc(s, gfpflags, node, addr, c);
 
        else {
-#ifdef CONFIG_CMPXCHG_LOCAL
                /*
                 * The cmpxchg will only match if there was no additional
                 * operation and if we are on the right processor.
@@ -1943,21 +1947,14 @@ redo:
                if (unlikely(!irqsafe_cpu_cmpxchg_double(
                                s->cpu_slab->freelist, s->cpu_slab->tid,
                                object, tid,
-                               get_freepointer(s, object), next_tid(tid)))) {
+                               get_freepointer_safe(s, object), next_tid(tid)))) {
 
                        note_cmpxchg_failure("slab_alloc", s, tid);
                        goto redo;
                }
-#else
-               c->freelist = get_freepointer(s, object);
-#endif
                stat(s, ALLOC_FASTPATH);
        }
 
-#ifndef CONFIG_CMPXCHG_LOCAL
-       local_irq_restore(flags);
-#endif
-
        if (unlikely(gfpflags & __GFP_ZERO) && object)
                memset(object, 0, s->objsize);
 
@@ -2034,18 +2031,15 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
 {
        void *prior;
        void **object = (void *)x;
-#ifdef CONFIG_CMPXCHG_LOCAL
        unsigned long flags;
 
        local_irq_save(flags);
-#endif
        slab_lock(page);
        stat(s, FREE_SLOWPATH);
 
-       if (kmem_cache_debug(s))
-               goto debug;
+       if (kmem_cache_debug(s) && !free_debug_processing(s, page, x, addr))
+               goto out_unlock;
 
-checks_ok:
        prior = page->freelist;
        set_freepointer(s, object, prior);
        page->freelist = object;
@@ -2070,9 +2064,7 @@ checks_ok:
 
 out_unlock:
        slab_unlock(page);
-#ifdef CONFIG_CMPXCHG_LOCAL
        local_irq_restore(flags);
-#endif
        return;
 
 slab_empty:
@@ -2084,17 +2076,9 @@ slab_empty:
                stat(s, FREE_REMOVE_PARTIAL);
        }
        slab_unlock(page);
-#ifdef CONFIG_CMPXCHG_LOCAL
        local_irq_restore(flags);
-#endif
        stat(s, FREE_SLAB);
        discard_slab(s, page);
-       return;
-
-debug:
-       if (!free_debug_processing(s, page, x, addr))
-               goto out_unlock;
-       goto checks_ok;
 }
 
 /*
@@ -2113,20 +2097,11 @@ static __always_inline void slab_free(struct kmem_cache *s,
 {
        void **object = (void *)x;
        struct kmem_cache_cpu *c;
-#ifdef CONFIG_CMPXCHG_LOCAL
        unsigned long tid;
-#else
-       unsigned long flags;
-#endif
 
        slab_free_hook(s, x);
 
-#ifndef CONFIG_CMPXCHG_LOCAL
-       local_irq_save(flags);
-
-#else
 redo:
-#endif
 
        /*
         * Determine the currently cpus per cpu slab.
@@ -2136,15 +2111,12 @@ redo:
         */
        c = __this_cpu_ptr(s->cpu_slab);
 
-#ifdef CONFIG_CMPXCHG_LOCAL
        tid = c->tid;
        barrier();
-#endif
 
-       if (likely(page == c->page && c->node != NUMA_NO_NODE)) {
+       if (likely(page == c->page)) {
                set_freepointer(s, object, c->freelist);
 
-#ifdef CONFIG_CMPXCHG_LOCAL
                if (unlikely(!irqsafe_cpu_cmpxchg_double(
                                s->cpu_slab->freelist, s->cpu_slab->tid,
                                c->freelist, tid,
@@ -2153,16 +2125,10 @@ redo:
                        note_cmpxchg_failure("slab_free", s, tid);
                        goto redo;
                }
-#else
-               c->freelist = object;
-#endif
                stat(s, FREE_FASTPATH);
        } else
                __slab_free(s, page, x, addr);
 
-#ifndef CONFIG_CMPXCHG_LOCAL
-       local_irq_restore(flags);
-#endif
 }
 
 void kmem_cache_free(struct kmem_cache *s, void *x)
@@ -2673,9 +2639,8 @@ static void list_slab_objects(struct kmem_cache *s, struct page *page,
                return;
        slab_err(s, page, "%s", text);
        slab_lock(page);
-       for_each_free_object(p, s, page->freelist)
-               set_bit(slab_index(p, s, addr), map);
 
+       get_map(s, page, map);
        for_each_object(p, s, addr, page->objects) {
 
                if (!test_bit(slab_index(p, s, addr), map)) {
@@ -3203,7 +3168,7 @@ static void __init kmem_cache_bootstrap_fixup(struct kmem_cache *s)
                        list_for_each_entry(p, &n->partial, lru)
                                p->slab = s;
 
-#ifdef CONFIG_SLAB_DEBUG
+#ifdef CONFIG_SLUB_DEBUG
                        list_for_each_entry(p, &n->full, lru)
                                p->slab = s;
 #endif
@@ -3610,10 +3575,11 @@ static int validate_slab(struct kmem_cache *s, struct page *page,
        /* Now we know that a valid freelist exists */
        bitmap_zero(map, page->objects);
 
-       for_each_free_object(p, s, page->freelist) {
-               set_bit(slab_index(p, s, addr), map);
-               if (!check_object(s, page, p, SLUB_RED_INACTIVE))
-                       return 0;
+       get_map(s, page, map);
+       for_each_object(p, s, addr, page->objects) {
+               if (test_bit(slab_index(p, s, addr), map))
+                       if (!check_object(s, page, p, SLUB_RED_INACTIVE))
+                               return 0;
        }
 
        for_each_object(p, s, addr, page->objects)
@@ -3821,8 +3787,7 @@ static void process_slab(struct loc_track *t, struct kmem_cache *s,
        void *p;
 
        bitmap_zero(map, page->objects);
-       for_each_free_object(p, s, page->freelist)
-               set_bit(slab_index(p, s, addr), map);
+       get_map(s, page, map);
 
        for_each_object(p, s, addr, page->objects)
                if (!test_bit(slab_index(p, s, addr), map))