diff options
Diffstat (limited to 'mm/slub.c')
| -rw-r--r-- | mm/slub.c | 204 |
1 files changed, 89 insertions, 115 deletions
diff --git a/mm/slub.c b/mm/slub.c index 74c65af0a54f..0863fd38a5ce 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -291,32 +291,16 @@ static inline struct kmem_cache_cpu *get_cpu_slab(struct kmem_cache *s, int cpu) #endif } -/* - * The end pointer in a slab is special. It points to the first object in the - * slab but has bit 0 set to mark it. - * - * Note that SLUB relies on page_mapping returning NULL for pages with bit 0 - * in the mapping set. - */ -static inline int is_end(void *addr) -{ - return (unsigned long)addr & PAGE_MAPPING_ANON; -} - -static void *slab_address(struct page *page) -{ - return page->end - PAGE_MAPPING_ANON; -} - +/* 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) { void *base; - if (object == page->end) + if (!object) return 1; - base = slab_address(page); + base = page_address(page); if (object < base || object >= base + s->objects * s->size || (object - base) % s->size) { return 0; @@ -349,8 +333,7 @@ static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp) /* Scan freelist */ #define for_each_free_object(__p, __s, __free) \ - for (__p = (__free); (__p) != page->end; __p = get_freepointer((__s),\ - __p)) + 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) @@ -502,7 +485,7 @@ static void slab_fix(struct kmem_cache *s, char *fmt, ...) static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p) { unsigned int off; /* Offset of last byte */ - u8 *addr = slab_address(page); + u8 *addr = page_address(page); print_tracking(s, p); @@ -637,7 +620,7 @@ static int check_bytes_and_report(struct kmem_cache *s, struct page *page, * A. Free pointer (if we cannot overwrite object on free) * B. Tracking data for SLAB_STORE_USER * C. Padding to reach required alignment boundary or at mininum - * one word if debuggin is on to be able to detect writes + * one word if debugging is on to be able to detect writes * before the word boundary. * * Padding is done using 0x5a (POISON_INUSE) @@ -680,7 +663,7 @@ static int slab_pad_check(struct kmem_cache *s, struct page *page) if (!(s->flags & SLAB_POISON)) return 1; - start = slab_address(page); + start = page_address(page); end = start + (PAGE_SIZE << s->order); length = s->objects * s->size; remainder = end - (start + length); @@ -748,7 +731,7 @@ static int check_object(struct kmem_cache *s, struct page *page, * of the free objects in this slab. May cause * another error because the object count is now wrong. */ - set_freepointer(s, p, page->end); + set_freepointer(s, p, NULL); return 0; } return 1; @@ -782,18 +765,18 @@ static int on_freelist(struct kmem_cache *s, struct page *page, void *search) void *fp = page->freelist; void *object = NULL; - while (fp != page->end && nr <= s->objects) { + while (fp && nr <= s->objects) { if (fp == search) return 1; if (!check_valid_pointer(s, page, fp)) { if (object) { object_err(s, page, object, "Freechain corrupt"); - set_freepointer(s, object, page->end); + set_freepointer(s, object, NULL); break; } else { slab_err(s, page, "Freepointer corrupt"); - page->freelist = page->end; + page->freelist = NULL; page->inuse = s->objects; slab_fix(s, "Freelist cleared"); return 0; @@ -870,7 +853,7 @@ static int alloc_debug_processing(struct kmem_cache *s, struct page *page, if (!check_slab(s, page)) goto bad; - if (object && !on_freelist(s, page, object)) { + if (!on_freelist(s, page, object)) { object_err(s, page, object, "Object already allocated"); goto bad; } @@ -880,7 +863,7 @@ static int alloc_debug_processing(struct kmem_cache *s, struct page *page, goto bad; } - if (object && !check_object(s, page, object, 0)) + if (!check_object(s, page, object, 0)) goto bad; /* Success perform special debug activities for allocs */ @@ -899,7 +882,7 @@ bad: */ slab_fix(s, "Marking all objects used"); page->inuse = s->objects; - page->freelist = page->end; + page->freelist = NULL; } return 0; } @@ -939,7 +922,7 @@ static int free_debug_processing(struct kmem_cache *s, struct page *page, } /* Special debug activities for freeing objects */ - if (!SlabFrozen(page) && page->freelist == page->end) + if (!SlabFrozen(page) && !page->freelist) remove_full(s, page); if (s->flags & SLAB_STORE_USER) set_track(s, object, TRACK_FREE, addr); @@ -1015,30 +998,11 @@ static unsigned long kmem_cache_flags(unsigned long objsize, void (*ctor)(struct kmem_cache *, void *)) { /* - * The page->offset field is only 16 bit wide. This is an offset - * in units of words from the beginning of an object. If the slab - * size is bigger then we cannot move the free pointer behind the - * object anymore. - * - * On 32 bit platforms the limit is 256k. On 64bit platforms - * the limit is 512k. - * - * Debugging or ctor may create a need to move the free - * pointer. Fail if this happens. + * Enable debugging if selected on the kernel commandline. */ - if (objsize >= 65535 * sizeof(void *)) { - BUG_ON(flags & (SLAB_RED_ZONE | SLAB_POISON | - SLAB_STORE_USER | SLAB_DESTROY_BY_RCU)); - BUG_ON(ctor); - } else { - /* - * Enable debugging if selected on the kernel commandline. - */ - if (slub_debug && (!slub_debug_slabs || - strncmp(slub_debug_slabs, name, - strlen(slub_debug_slabs)) == 0)) - flags |= slub_debug; - } + if (slub_debug && (!slub_debug_slabs || + strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs)) == 0)) + flags |= slub_debug; return flags; } @@ -1124,7 +1088,6 @@ static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node) SetSlabDebug(page); start = page_address(page); - page->end = start + 1; if (unlikely(s->flags & SLAB_POISON)) memset(start, POISON_INUSE, PAGE_SIZE << s->order); @@ -1136,7 +1099,7 @@ static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node) last = p; } setup_object(s, page, last); - set_freepointer(s, last, page->end); + set_freepointer(s, last, NULL); page->freelist = start; page->inuse = 0; @@ -1152,7 +1115,7 @@ static void __free_slab(struct kmem_cache *s, struct page *page) void *p; slab_pad_check(s, page); - for_each_object(p, s, slab_address(page)) + for_each_object(p, s, page_address(page)) check_object(s, page, p, 0); ClearSlabDebug(page); } @@ -1162,7 +1125,6 @@ static void __free_slab(struct kmem_cache *s, struct page *page) NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE, -pages); - page->mapping = NULL; __free_pages(page, s->order); } @@ -1307,7 +1269,7 @@ static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags) * may return off node objects because partial slabs are obtained * from other nodes and filled up. * - * If /sys/slab/xx/defrag_ratio is set to 100 (which makes + * If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes * defrag_ratio = 1000) then every (well almost) allocation will * first attempt to defrag slab caches on other nodes. This means * scanning over all nodes to look for partial slabs which may be @@ -1366,7 +1328,7 @@ static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail) ClearSlabFrozen(page); if (page->inuse) { - if (page->freelist != page->end) { + if (page->freelist) { add_partial(n, page, tail); stat(c, tail ? DEACTIVATE_TO_TAIL : DEACTIVATE_TO_HEAD); } else { @@ -1382,9 +1344,11 @@ static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail) * Adding an empty slab to the partial slabs in order * to avoid page allocator overhead. This slab needs * to come after the other slabs with objects in - * order to fill them up. That way the size of the - * partial list stays small. kmem_cache_shrink can - * reclaim empty slabs from the partial list. + * so that the others get filled first. That way the + * size of the partial list stays small. + * + * kmem_cache_shrink can reclaim any empty slabs from the + * partial list. */ add_partial(n, page, 1); slab_unlock(page); @@ -1407,15 +1371,11 @@ static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c) if (c->freelist) stat(c, DEACTIVATE_REMOTE_FREES); /* - * Merge cpu freelist into freelist. Typically we get here + * Merge cpu freelist into slab freelist. Typically we get here * because both freelists are empty. So this is unlikely * to occur. - * - * We need to use _is_end here because deactivate slab may - * be called for a debug slab. Then c->freelist may contain - * a dummy pointer. */ - while (unlikely(!is_end(c->freelist))) { + while (unlikely(c->freelist)) { void **object; tail = 0; /* Hot objects. Put the slab first */ @@ -1442,6 +1402,7 @@ static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c) /* * Flush cpu slab. + * * Called from IPI handler with interrupts disabled. */ static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu) @@ -1500,7 +1461,8 @@ static inline int node_match(struct kmem_cache_cpu *c, int node) * rest of the freelist to the lockless freelist. * * And if we were unable to get a new slab from the partial slab lists then - * we need to allocate a new slab. This is slowest path since we may sleep. + * we need to allocate a new slab. This is the slowest path since it involves + * a call to the page allocator and the setup of a new slab. */ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, void *addr, struct kmem_cache_cpu *c) @@ -1514,18 +1476,19 @@ static void *__slab_alloc(struct kmem_cache *s, slab_lock(c->page); if (unlikely(!node_match(c, node))) goto another_slab; + stat(c, ALLOC_REFILL); + load_freelist: object = c->page->freelist; - if (unlikely(object == c->page->end)) + if (unlikely(!object)) goto another_slab; if (unlikely(SlabDebug(c->page))) goto debug; - object = c->page->freelist; c->freelist = object[c->offset]; c->page->inuse = s->objects; - c->page->freelist = c->page->end; + c->page->freelist = NULL; c->node = page_to_nid(c->page); unlock_out: slab_unlock(c->page); @@ -1578,7 +1541,6 @@ new_slab: return NULL; debug: - object = c->page->freelist; if (!alloc_debug_processing(s, c->page, object, addr)) goto another_slab; @@ -1607,7 +1569,7 @@ static __always_inline void *slab_alloc(struct kmem_cache *s, local_irq_save(flags); c = get_cpu_slab(s, smp_processor_id()); - if (unlikely(is_end(c->freelist) || !node_match(c, node))) + if (unlikely(!c->freelist || !node_match(c, node))) object = __slab_alloc(s, gfpflags, node, addr, c); @@ -1659,6 +1621,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page, if (unlikely(SlabDebug(page))) goto debug; + checks_ok: prior = object[offset] = page->freelist; page->freelist = object; @@ -1673,11 +1636,10 @@ checks_ok: goto slab_empty; /* - * Objects left in the slab. If it - * was not on the partial list before + * Objects left in the slab. If it was not on the partial list before * then add it. */ - if (unlikely(prior == page->end)) { + if (unlikely(!prior)) { add_partial(get_node(s, page_to_nid(page)), page, 1); stat(c, FREE_ADD_PARTIAL); } @@ -1687,7 +1649,7 @@ out_unlock: return; slab_empty: - if (prior != page->end) { + if (prior) { /* * Slab still on the partial list. */ @@ -1724,8 +1686,8 @@ static __always_inline void slab_free(struct kmem_cache *s, unsigned long flags; local_irq_save(flags); - debug_check_no_locks_freed(object, s->objsize); c = get_cpu_slab(s, smp_processor_id()); + debug_check_no_locks_freed(object, c->objsize); if (likely(page == c->page && c->node >= 0)) { object[c->offset] = c->freelist; c->freelist = object; @@ -1888,13 +1850,11 @@ static unsigned long calculate_alignment(unsigned long flags, unsigned long align, unsigned long size) { /* - * If the user wants hardware cache aligned objects then - * follow that suggestion if the object is sufficiently - * large. + * If the user wants hardware cache aligned objects then follow that + * suggestion if the object is sufficiently large. * - * The hardware cache alignment cannot override the - * specified alignment though. If that is greater - * then use it. + * The hardware cache alignment cannot override the specified + * alignment though. If that is greater then use it. */ if ((flags & SLAB_HWCACHE_ALIGN) && size > cache_line_size() / 2) @@ -1910,7 +1870,7 @@ static void init_kmem_cache_cpu(struct kmem_cache *s, struct kmem_cache_cpu *c) { c->page = NULL; - c->freelist = (void *)PAGE_MAPPING_ANON; + c->freelist = NULL; c->node = 0; c->offset = s->offset / sizeof(void *); c->objsize = s->objsize; @@ -2092,6 +2052,7 @@ static struct kmem_cache_node *early_kmem_cache_node_alloc(gfp_t gfpflags, #endif init_kmem_cache_node(n); atomic_long_inc(&n->nr_slabs); + /* * lockdep requires consistent irq usage for each lock * so even though there cannot be a race this early in @@ -2173,6 +2134,14 @@ static int calculate_sizes(struct kmem_cache *s) unsigned long align = s->align; /* + * Round up object size to the next word boundary. We can only + * place the free pointer at word boundaries and this determines + * the possible location of the free pointer. + */ + size = ALIGN(size, sizeof(void *)); + +#ifdef CONFIG_SLUB_DEBUG + /* * Determine if we can poison the object itself. If the user of * the slab may touch the object after free or before allocation * then we should never poison the object itself. @@ -2183,14 +2152,7 @@ static int calculate_sizes(struct kmem_cache *s) else s->flags &= ~__OBJECT_POISON; - /* - * Round up object size to the next word boundary. We can only - * place the free pointer at word boundaries and this determines - * the possible location of the free pointer. - */ - size = ALIGN(size, sizeof(void *)); -#ifdef CONFIG_SLUB_DEBUG /* * If we are Redzoning then check if there is some space between the * end of the object and the free pointer. If not then add an @@ -2343,7 +2305,7 @@ int kmem_ptr_validate(struct kmem_cache *s, const void *object) /* * We could also check if the object is on the slabs freelist. * But this would be too expensive and it seems that the main - * purpose of kmem_ptr_valid is to check if the object belongs + * purpose of kmem_ptr_valid() is to check if the object belongs * to a certain slab. */ return 1; @@ -2630,13 +2592,24 @@ void *__kmalloc(size_t size, gfp_t flags) } EXPORT_SYMBOL(__kmalloc); +static void *kmalloc_large_node(size_t size, gfp_t flags, int node) +{ + struct page *page = alloc_pages_node(node, flags | __GFP_COMP, + get_order(size)); + + if (page) + return page_address(page); + else + return NULL; +} + #ifdef CONFIG_NUMA void *__kmalloc_node(size_t size, gfp_t flags, int node) { struct kmem_cache *s; if (unlikely(size > PAGE_SIZE)) - return kmalloc_large(size, flags); + return kmalloc_large_node(size, flags, node); s = get_slab(size, flags); @@ -2653,19 +2626,17 @@ size_t ksize(const void *object) struct page *page; struct kmem_cache *s; - BUG_ON(!object); if (unlikely(object == ZERO_SIZE_PTR)) return 0; page = virt_to_head_page(object); - BUG_ON(!page); if (unlikely(!PageSlab(page))) return PAGE_SIZE << compound_order(page); s = page->slab; - BUG_ON(!s); +#ifdef CONFIG_SLUB_DEBUG /* * Debugging requires use of the padding between object * and whatever may come after it. @@ -2673,6 +2644,7 @@ size_t ksize(const void *object) if (s->flags & (SLAB_RED_ZONE | SLAB_POISON)) return s->objsize; +#endif /* * If we have the need to store the freelist pointer * back there or track user information then we can @@ -2680,7 +2652,6 @@ size_t ksize(const void *object) */ if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER)) return s->inuse; - /* * Else we can use all the padding etc for the allocation */ @@ -2957,7 +2928,7 @@ void __init kmem_cache_init(void) /* * Patch up the size_index table if we have strange large alignment * requirements for the kmalloc array. This is only the case for - * mips it seems. The standard arches will not generate any code here. + * MIPS it seems. The standard arches will not generate any code here. * * Largest permitted alignment is 256 bytes due to the way we * handle the index determination for the smaller caches. @@ -2986,7 +2957,6 @@ void __init kmem_cache_init(void) kmem_size = sizeof(struct kmem_cache); #endif - printk(KERN_INFO "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d," " CPUs=%d, Nodes=%d\n", @@ -3083,12 +3053,15 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size, */ 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); + if (sysfs_slab_alias(s, name)) goto err; return s; } + s = kmalloc(kmem_size, GFP_KERNEL); if (s) { if (kmem_cache_open(s, GFP_KERNEL, name, @@ -3184,7 +3157,7 @@ void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags, struct kmem_cache *s; if (unlikely(size > PAGE_SIZE)) - return kmalloc_large(size, gfpflags); + return kmalloc_large_node(size, gfpflags, node); s = get_slab(size, gfpflags); @@ -3199,7 +3172,7 @@ static int validate_slab(struct kmem_cache *s, struct page *page, unsigned long *map) { void *p; - void *addr = slab_address(page); + void *addr = page_address(page); if (!check_slab(s, page) || !on_freelist(s, page, NULL)) @@ -3482,7 +3455,7 @@ static int add_location(struct loc_track *t, struct kmem_cache *s, static void process_slab(struct loc_track *t, struct kmem_cache *s, struct page *page, enum track_item alloc) { - void *addr = slab_address(page); + void *addr = page_address(page); DECLARE_BITMAP(map, s->objects); void *p; @@ -3591,8 +3564,8 @@ enum slab_stat_type { #define SO_CPU (1 << SL_CPU) #define SO_OBJECTS (1 << SL_OBJECTS) -static unsigned long slab_objects(struct kmem_cache *s, - char *buf, unsigned long flags) +static ssize_t show_slab_objects(struct kmem_cache *s, + char *buf, unsigned long flags) { unsigned long total = 0; int cpu; @@ -3602,6 +3575,8 @@ static unsigned long slab_objects(struct kmem_cache *s, unsigned long *per_cpu; nodes = kzalloc(2 * sizeof(unsigned long) * nr_node_ids, GFP_KERNEL); + if (!nodes) + return -ENOMEM; per_cpu = nodes + nr_node_ids; for_each_possible_cpu(cpu) { @@ -3754,25 +3729,25 @@ SLAB_ATTR_RO(aliases); static ssize_t slabs_show(struct kmem_cache *s, char *buf) { - return slab_objects(s, buf, SO_FULL|SO_PARTIAL|SO_CPU); + return show_slab_objects(s, buf, SO_FULL|SO_PARTIAL|SO_CPU); } SLAB_ATTR_RO(slabs); static ssize_t partial_show(struct kmem_cache *s, char *buf) { - return slab_objects(s, buf, SO_PARTIAL); + return show_slab_objects(s, buf, SO_PARTIAL); } SLAB_ATTR_RO(partial); static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf) { - return slab_objects(s, buf, SO_CPU); + return show_slab_objects(s, buf, SO_CPU); } SLAB_ATTR_RO(cpu_slabs); static ssize_t objects_show(struct kmem_cache *s, char *buf) { - return slab_objects(s, buf, SO_FULL|SO_PARTIAL|SO_CPU|SO_OBJECTS); + return show_slab_objects(s, buf, SO_FULL|SO_PARTIAL|SO_CPU|SO_OBJECTS); } SLAB_ATTR_RO(objects); @@ -3971,7 +3946,6 @@ SLAB_ATTR(remote_node_defrag_ratio); #endif #ifdef CONFIG_SLUB_STATS - static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si) { unsigned long sum = 0; @@ -4155,8 +4129,8 @@ static struct kset *slab_kset; #define ID_STR_LENGTH 64 /* Create a unique string id for a slab cache: - * format - * :[flags-]size:[memory address of kmemcache] + * + * Format :[flags-]size */ static char *create_unique_id(struct kmem_cache *s) { |