X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=mm%2Fslab.c;h=31ea409b8e6dc66e8ffd4e7278eacf710b04f7dc;hb=a2f44b27303a5353859d77a3e96a1d3f33f56ab7;hp=0d9cf0921d9323d4afba3fe233822550960b8f2a;hpb=567f20a20be06ad546b5962340c4be268462055b;p=linux-2.6.git diff --git a/mm/slab.c b/mm/slab.c index 0d9cf0921..31ea409b8 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -103,12 +103,14 @@ #include #include #include +#include #include #include #include +#include #include +#include -#include #include #include #include @@ -312,8 +314,8 @@ static int drain_freelist(struct kmem_cache *cache, struct kmem_list3 *l3, int tofree); static void free_block(struct kmem_cache *cachep, void **objpp, int len, int node); -static void enable_cpucache(struct kmem_cache *cachep); -static void cache_reap(void *unused); +static int enable_cpucache(struct kmem_cache *cachep); +static void cache_reap(struct work_struct *unused); /* * This function must be completely optimized away if a constant is passed to @@ -385,6 +387,7 @@ struct kmem_cache { unsigned int shared; unsigned int buffer_size; + u32 reciprocal_buffer_size; /* 3) touched by every alloc & free from the backend */ struct kmem_list3 *nodelists[MAX_NUMNODES]; @@ -499,6 +502,8 @@ struct kmem_cache { #define STATS_INC_FREEMISS(x) do { } while (0) #endif +#include "slab_vs.h" + #if DEBUG /* @@ -626,10 +631,17 @@ static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab, return slab->s_mem + cache->buffer_size * idx; } -static inline unsigned int obj_to_index(struct kmem_cache *cache, - struct slab *slab, void *obj) +/* + * We want to avoid an expensive divide : (offset / cache->buffer_size) + * Using the fact that buffer_size is a constant for a particular cache, + * we can replace (offset / cache->buffer_size) by + * reciprocal_divide(offset, cache->reciprocal_buffer_size) + */ +static inline unsigned int obj_to_index(const struct kmem_cache *cache, + const struct slab *slab, void *obj) { - return (unsigned)(obj - slab->s_mem) / cache->buffer_size; + u32 offset = (obj - slab->s_mem); + return reciprocal_divide(offset, cache->reciprocal_buffer_size); } /* @@ -730,17 +742,12 @@ static inline void init_lock_keys(void) } #endif -/* Guard access to the cache-chain. */ -static DEFINE_MUTEX(cache_chain_mutex); -static struct list_head cache_chain; - /* - * vm_enough_memory() looks at this to determine how many slab-allocated pages - * are possibly freeable under pressure - * - * SLAB_RECLAIM_ACCOUNT turns this on per-slab + * 1. Guard access to the cache-chain. + * 2. Protect sanity of cpu_online_map against cpu hotplug events */ -atomic_t slab_reclaim_pages; +static DEFINE_MUTEX(cache_chain_mutex); +static struct list_head cache_chain; /* * chicken and egg problem: delay the per-cpu array allocation @@ -761,7 +768,7 @@ int slab_is_available(void) return g_cpucache_up == FULL; } -static DEFINE_PER_CPU(struct work_struct, reap_work); +static DEFINE_PER_CPU(struct delayed_work, reap_work); static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep) { @@ -793,11 +800,10 @@ static inline struct kmem_cache *__find_general_cachep(size_t size, return csizep->cs_cachep; } -struct kmem_cache *kmem_find_general_cachep(size_t size, gfp_t gfpflags) +static struct kmem_cache *kmem_find_general_cachep(size_t size, gfp_t gfpflags) { return __find_general_cachep(size, gfpflags); } -EXPORT_SYMBOL(kmem_find_general_cachep); static size_t slab_mgmt_size(size_t nr_objs, size_t align) { @@ -875,6 +881,22 @@ static void __slab_error(const char *function, struct kmem_cache *cachep, dump_stack(); } +/* + * By default on NUMA we use alien caches to stage the freeing of + * objects allocated from other nodes. This causes massive memory + * inefficiencies when using fake NUMA setup to split memory into a + * large number of small nodes, so it can be disabled on the command + * line + */ + +static int use_alien_caches __read_mostly = 1; +static int __init noaliencache_setup(char *s) +{ + use_alien_caches = 0; + return 1; +} +__setup("noaliencache", noaliencache_setup); + #ifdef CONFIG_NUMA /* * Special reaping functions for NUMA systems called from cache_reap(). @@ -925,17 +947,18 @@ static void next_reap_node(void) */ static void __devinit start_cpu_timer(int cpu) { - struct work_struct *reap_work = &per_cpu(reap_work, cpu); + struct delayed_work *reap_work = &per_cpu(reap_work, cpu); /* * When this gets called from do_initcalls via cpucache_init(), * init_workqueues() has already run, so keventd will be setup * at that time. */ - if (keventd_up() && reap_work->func == NULL) { + if (keventd_up() && reap_work->work.func == NULL) { init_reap_node(cpu); - INIT_WORK(reap_work, cache_reap, NULL); - schedule_delayed_work_on(cpu, reap_work, HZ + 3 * cpu); + INIT_DELAYED_WORK(reap_work, cache_reap); + schedule_delayed_work_on(cpu, reap_work, + __round_jiffies_relative(HZ, cpu)); } } @@ -980,8 +1003,40 @@ static int transfer_objects(struct array_cache *to, return nr; } -#ifdef CONFIG_NUMA -static void *__cache_alloc_node(struct kmem_cache *, gfp_t, int); +#ifndef CONFIG_NUMA + +#define drain_alien_cache(cachep, alien) do { } while (0) +#define reap_alien(cachep, l3) do { } while (0) + +static inline struct array_cache **alloc_alien_cache(int node, int limit) +{ + return (struct array_cache **)BAD_ALIEN_MAGIC; +} + +static inline void free_alien_cache(struct array_cache **ac_ptr) +{ +} + +static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) +{ + return 0; +} + +static inline void *alternate_node_alloc(struct kmem_cache *cachep, + gfp_t flags) +{ + return NULL; +} + +static inline void *____cache_alloc_node(struct kmem_cache *cachep, + gfp_t flags, int nodeid) +{ + return NULL; +} + +#else /* CONFIG_NUMA */ + +static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int); static void *alternate_node_alloc(struct kmem_cache *, gfp_t); static struct array_cache **alloc_alien_cache(int node, int limit) @@ -1083,15 +1138,18 @@ static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) int nodeid = slabp->nodeid; struct kmem_list3 *l3; struct array_cache *alien = NULL; + int node; + + node = numa_node_id(); /* * Make sure we are not freeing a object from another node to the array * cache on this cpu. */ - if (likely(slabp->nodeid == numa_node_id())) + if (likely(slabp->nodeid == node) || unlikely(!use_alien_caches)) return 0; - l3 = cachep->nodelists[numa_node_id()]; + l3 = cachep->nodelists[node]; STATS_INC_NODEFREES(cachep); if (l3->alien && l3->alien[nodeid]) { alien = l3->alien[nodeid]; @@ -1109,26 +1167,6 @@ static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) } return 1; } - -#else - -#define drain_alien_cache(cachep, alien) do { } while (0) -#define reap_alien(cachep, l3) do { } while (0) - -static inline struct array_cache **alloc_alien_cache(int node, int limit) -{ - return (struct array_cache **)BAD_ALIEN_MAGIC; -} - -static inline void free_alien_cache(struct array_cache **ac_ptr) -{ -} - -static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) -{ - return 0; -} - #endif static int __cpuinit cpuup_callback(struct notifier_block *nfb, @@ -1186,7 +1224,7 @@ static int __cpuinit cpuup_callback(struct notifier_block *nfb, list_for_each_entry(cachep, &cache_chain, next) { struct array_cache *nc; struct array_cache *shared; - struct array_cache **alien; + struct array_cache **alien = NULL; nc = alloc_arraycache(node, cachep->limit, cachep->batchcount); @@ -1198,9 +1236,11 @@ static int __cpuinit cpuup_callback(struct notifier_block *nfb, if (!shared) goto bad; - alien = alloc_alien_cache(node, cachep->limit); - if (!alien) - goto bad; + if (use_alien_caches) { + alien = alloc_alien_cache(node, cachep->limit); + if (!alien) + goto bad; + } cachep->array[cpu] = nc; l3 = cachep->nodelists[node]; BUG_ON(!l3); @@ -1224,12 +1264,18 @@ static int __cpuinit cpuup_callback(struct notifier_block *nfb, kfree(shared); free_alien_cache(alien); } - mutex_unlock(&cache_chain_mutex); break; case CPU_ONLINE: + mutex_unlock(&cache_chain_mutex); start_cpu_timer(cpu); break; #ifdef CONFIG_HOTPLUG_CPU + case CPU_DOWN_PREPARE: + mutex_lock(&cache_chain_mutex); + break; + case CPU_DOWN_FAILED: + mutex_unlock(&cache_chain_mutex); + break; case CPU_DEAD: /* * Even if all the cpus of a node are down, we don't free the @@ -1240,8 +1286,8 @@ static int __cpuinit cpuup_callback(struct notifier_block *nfb, * gets destroyed at kmem_cache_destroy(). */ /* fall thru */ +#endif case CPU_UP_CANCELED: - mutex_lock(&cache_chain_mutex); list_for_each_entry(cachep, &cache_chain, next) { struct array_cache *nc; struct array_cache *shared; @@ -1302,11 +1348,9 @@ free_array_cache: } mutex_unlock(&cache_chain_mutex); break; -#endif } return NOTIFY_OK; bad: - mutex_unlock(&cache_chain_mutex); return NOTIFY_BAD; } @@ -1322,7 +1366,6 @@ static void init_list(struct kmem_cache *cachep, struct kmem_list3 *list, { struct kmem_list3 *ptr; - BUG_ON(cachep->nodelists[nodeid] != list); ptr = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, nodeid); BUG_ON(!ptr); @@ -1349,6 +1392,7 @@ void __init kmem_cache_init(void) struct cache_names *names; int i; int order; + int node; for (i = 0; i < NUM_INIT_LISTS; i++) { kmem_list3_init(&initkmem_list3[i]); @@ -1383,15 +1427,19 @@ void __init kmem_cache_init(void) * 6) Resize the head arrays of the kmalloc caches to their final sizes. */ + node = numa_node_id(); + /* 1) create the cache_cache */ INIT_LIST_HEAD(&cache_chain); list_add(&cache_cache.next, &cache_chain); cache_cache.colour_off = cache_line_size(); cache_cache.array[smp_processor_id()] = &initarray_cache.cache; - cache_cache.nodelists[numa_node_id()] = &initkmem_list3[CACHE_CACHE]; + cache_cache.nodelists[node] = &initkmem_list3[CACHE_CACHE]; cache_cache.buffer_size = ALIGN(cache_cache.buffer_size, cache_line_size()); + cache_cache.reciprocal_buffer_size = + reciprocal_value(cache_cache.buffer_size); for (order = 0; order < MAX_ORDER; order++) { cache_estimate(order, cache_cache.buffer_size, @@ -1493,19 +1541,18 @@ void __init kmem_cache_init(void) } /* 5) Replace the bootstrap kmem_list3's */ { - int node; + int nid; + /* Replace the static kmem_list3 structures for the boot cpu */ - init_list(&cache_cache, &initkmem_list3[CACHE_CACHE], - numa_node_id()); + init_list(&cache_cache, &initkmem_list3[CACHE_CACHE], node); - for_each_online_node(node) { + for_each_online_node(nid) { init_list(malloc_sizes[INDEX_AC].cs_cachep, - &initkmem_list3[SIZE_AC + node], node); + &initkmem_list3[SIZE_AC + nid], nid); if (INDEX_AC != INDEX_L3) { init_list(malloc_sizes[INDEX_L3].cs_cachep, - &initkmem_list3[SIZE_L3 + node], - node); + &initkmem_list3[SIZE_L3 + nid], nid); } } } @@ -1515,7 +1562,8 @@ void __init kmem_cache_init(void) struct kmem_cache *cachep; mutex_lock(&cache_chain_mutex); list_for_each_entry(cachep, &cache_chain, next) - enable_cpucache(cachep); + if (enable_cpucache(cachep)) + BUG(); mutex_unlock(&cache_chain_mutex); } @@ -1571,6 +1619,7 @@ static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid) */ flags |= __GFP_COMP; #endif + flags |= cachep->gfpflags; page = alloc_pages_node(nodeid, flags, cachep->gfporder); @@ -1579,8 +1628,11 @@ static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid) nr_pages = (1 << cachep->gfporder); if (cachep->flags & SLAB_RECLAIM_ACCOUNT) - atomic_add(nr_pages, &slab_reclaim_pages); - add_zone_page_state(page_zone(page), NR_SLAB, nr_pages); + add_zone_page_state(page_zone(page), + NR_SLAB_RECLAIMABLE, nr_pages); + else + add_zone_page_state(page_zone(page), + NR_SLAB_UNRECLAIMABLE, nr_pages); for (i = 0; i < nr_pages; i++) __SetPageSlab(page + i); return page_address(page); @@ -1595,7 +1647,12 @@ static void kmem_freepages(struct kmem_cache *cachep, void *addr) struct page *page = virt_to_page(addr); const unsigned long nr_freed = i; - sub_zone_page_state(page_zone(page), NR_SLAB, nr_freed); + if (cachep->flags & SLAB_RECLAIM_ACCOUNT) + sub_zone_page_state(page_zone(page), + NR_SLAB_RECLAIMABLE, nr_freed); + else + sub_zone_page_state(page_zone(page), + NR_SLAB_UNRECLAIMABLE, nr_freed); while (i--) { BUG_ON(!PageSlab(page)); __ClearPageSlab(page); @@ -1604,8 +1661,6 @@ static void kmem_freepages(struct kmem_cache *cachep, void *addr) if (current->reclaim_state) current->reclaim_state->reclaimed_slab += nr_freed; free_pages((unsigned long)addr, cachep->gfporder); - if (cachep->flags & SLAB_RECLAIM_ACCOUNT) - atomic_sub(1 << cachep->gfporder, &slab_reclaim_pages); } static void kmem_rcu_free(struct rcu_head *head) @@ -1666,11 +1721,13 @@ static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val) static void dump_line(char *data, int offset, int limit) { int i; - unsigned char total = 0, bad_count = 0, errors; + unsigned char error = 0; + int bad_count = 0; + printk(KERN_ERR "%03x:", offset); for (i = 0; i < limit; i++) { if (data[offset + i] != POISON_FREE) { - total += data[offset + i]; + error = data[offset + i]; bad_count++; } printk(" %02x", (unsigned char)data[offset + i]); @@ -1678,11 +1735,13 @@ static void dump_line(char *data, int offset, int limit) printk("\n"); if (bad_count == 1) { - errors = total ^ POISON_FREE; - if (errors && !(errors & (errors-1))) { - printk(KERN_ERR "Single bit error detected. Probably bad RAM.\n"); + error ^= POISON_FREE; + if (!(error & (error - 1))) { + printk(KERN_ERR "Single bit error detected. Probably " + "bad RAM.\n"); #ifdef CONFIG_X86 - printk(KERN_ERR "Run memtest86+ or a similar memory test tool.\n"); + printk(KERN_ERR "Run memtest86+ or a similar memory " + "test tool.\n"); #else printk(KERN_ERR "Run a memory test tool.\n"); #endif @@ -1881,6 +1940,27 @@ static void set_up_list3s(struct kmem_cache *cachep, int index) } } +static void __kmem_cache_destroy(struct kmem_cache *cachep) +{ + int i; + struct kmem_list3 *l3; + + for_each_online_cpu(i) + kfree(cachep->array[i]); + + /* NUMA: free the list3 structures */ + for_each_online_node(i) { + l3 = cachep->nodelists[i]; + if (l3) { + kfree(l3->shared); + free_alien_cache(l3->alien); + kfree(l3); + } + } + kmem_cache_free(&cache_cache, cachep); +} + + /** * calculate_slab_order - calculate size (page order) of slabs * @cachep: pointer to the cache that is being created @@ -1951,12 +2031,11 @@ static size_t calculate_slab_order(struct kmem_cache *cachep, return left_over; } -static void setup_cpu_cache(struct kmem_cache *cachep) +static int setup_cpu_cache(struct kmem_cache *cachep) { - if (g_cpucache_up == FULL) { - enable_cpucache(cachep); - return; - } + if (g_cpucache_up == FULL) + return enable_cpucache(cachep); + if (g_cpucache_up == NONE) { /* * Note: the first kmem_cache_create must create the cache @@ -2003,6 +2082,7 @@ static void setup_cpu_cache(struct kmem_cache *cachep) cpu_cache_get(cachep)->touched = 0; cachep->batchcount = 1; cachep->limit = BOOT_CPUCACHE_ENTRIES; + return 0; } /** @@ -2054,15 +2134,12 @@ kmem_cache_create (const char *name, size_t size, size_t align, } /* - * Prevent CPUs from coming and going. - * lock_cpu_hotplug() nests outside cache_chain_mutex + * We use cache_chain_mutex to ensure a consistent view of + * cpu_online_map as well. Please see cpuup_callback */ - lock_cpu_hotplug(); - mutex_lock(&cache_chain_mutex); list_for_each_entry(pc, &cache_chain, next) { - mm_segment_t old_fs = get_fs(); char tmp; int res; @@ -2071,9 +2148,7 @@ kmem_cache_create (const char *name, size_t size, size_t align, * destroy its slab cache and no-one else reuses the vmalloc * area of the module. Print a warning. */ - set_fs(KERNEL_DS); - res = __get_user(tmp, pc->name); - set_fs(old_fs); + res = probe_kernel_address(pc->name, tmp); if (res) { printk("SLAB: cache with size %d has lost its name\n", pc->buffer_size); @@ -2144,46 +2219,52 @@ kmem_cache_create (const char *name, size_t size, size_t align, } else { ralign = BYTES_PER_WORD; } - /* 2) arch mandated alignment: disables debug if necessary */ + + /* + * Redzoning and user store require word alignment. Note this will be + * overridden by architecture or caller mandated alignment if either + * is greater than BYTES_PER_WORD. + */ + if (flags & SLAB_RED_ZONE || flags & SLAB_STORE_USER) + ralign = BYTES_PER_WORD; + + /* 2) arch mandated alignment */ if (ralign < ARCH_SLAB_MINALIGN) { ralign = ARCH_SLAB_MINALIGN; - if (ralign > BYTES_PER_WORD) - flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); } - /* 3) caller mandated alignment: disables debug if necessary */ + /* 3) caller mandated alignment */ if (ralign < align) { ralign = align; - if (ralign > BYTES_PER_WORD) - flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); } + /* disable debug if necessary */ + if (ralign > BYTES_PER_WORD) + flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); /* - * 4) Store it. Note that the debug code below can reduce - * the alignment to BYTES_PER_WORD. + * 4) Store it. */ align = ralign; /* Get cache's description obj. */ - cachep = kmem_cache_zalloc(&cache_cache, SLAB_KERNEL); + cachep = kmem_cache_zalloc(&cache_cache, GFP_KERNEL); if (!cachep) goto oops; #if DEBUG cachep->obj_size = size; + /* + * Both debugging options require word-alignment which is calculated + * into align above. + */ if (flags & SLAB_RED_ZONE) { - /* redzoning only works with word aligned caches */ - align = BYTES_PER_WORD; - /* add space for red zone words */ cachep->obj_offset += BYTES_PER_WORD; size += 2 * BYTES_PER_WORD; } if (flags & SLAB_STORE_USER) { - /* user store requires word alignment and - * one word storage behind the end of the real - * object. + /* user store requires one word storage behind the end of + * the real object. */ - align = BYTES_PER_WORD; size += BYTES_PER_WORD; } #if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC) @@ -2246,15 +2327,28 @@ kmem_cache_create (const char *name, size_t size, size_t align, if (flags & SLAB_CACHE_DMA) cachep->gfpflags |= GFP_DMA; cachep->buffer_size = size; + cachep->reciprocal_buffer_size = reciprocal_value(size); - if (flags & CFLGS_OFF_SLAB) + if (flags & CFLGS_OFF_SLAB) { cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u); + /* + * This is a possibility for one of the malloc_sizes caches. + * But since we go off slab only for object size greater than + * PAGE_SIZE/8, and malloc_sizes gets created in ascending order, + * this should not happen at all. + * But leave a BUG_ON for some lucky dude. + */ + BUG_ON(!cachep->slabp_cache); + } cachep->ctor = ctor; cachep->dtor = dtor; cachep->name = name; - - setup_cpu_cache(cachep); + if (setup_cpu_cache(cachep)) { + __kmem_cache_destroy(cachep); + cachep = NULL; + goto oops; + } /* cache setup completed, link it into the list */ list_add(&cachep->next, &cache_chain); @@ -2263,7 +2357,6 @@ oops: panic("kmem_cache_create(): failed to create slab `%s'\n", name); mutex_unlock(&cache_chain_mutex); - unlock_cpu_hotplug(); return cachep; } EXPORT_SYMBOL(kmem_cache_create); @@ -2381,6 +2474,7 @@ out: return nr_freed; } +/* Called with cache_chain_mutex held to protect against cpu hotplug */ static int __cache_shrink(struct kmem_cache *cachep) { int ret = 0, i = 0; @@ -2411,9 +2505,13 @@ static int __cache_shrink(struct kmem_cache *cachep) */ int kmem_cache_shrink(struct kmem_cache *cachep) { + int ret; BUG_ON(!cachep || in_interrupt()); - return __cache_shrink(cachep); + mutex_lock(&cache_chain_mutex); + ret = __cache_shrink(cachep); + mutex_unlock(&cache_chain_mutex); + return ret; } EXPORT_SYMBOL(kmem_cache_shrink); @@ -2422,7 +2520,6 @@ EXPORT_SYMBOL(kmem_cache_shrink); * @cachep: the cache to destroy * * Remove a struct kmem_cache object from the slab cache. - * Returns 0 on success. * * It is expected this function will be called by a module when it is * unloaded. This will remove the cache completely, and avoid a duplicate @@ -2434,55 +2531,42 @@ EXPORT_SYMBOL(kmem_cache_shrink); * The caller must guarantee that noone will allocate memory from the cache * during the kmem_cache_destroy(). */ -int kmem_cache_destroy(struct kmem_cache *cachep) +void kmem_cache_destroy(struct kmem_cache *cachep) { - int i; - struct kmem_list3 *l3; - BUG_ON(!cachep || in_interrupt()); - /* Don't let CPUs to come and go */ - lock_cpu_hotplug(); - /* Find the cache in the chain of caches. */ mutex_lock(&cache_chain_mutex); /* * the chain is never empty, cache_cache is never destroyed */ list_del(&cachep->next); - mutex_unlock(&cache_chain_mutex); - if (__cache_shrink(cachep)) { slab_error(cachep, "Can't free all objects"); - mutex_lock(&cache_chain_mutex); list_add(&cachep->next, &cache_chain); mutex_unlock(&cache_chain_mutex); - unlock_cpu_hotplug(); - return 1; + return; } if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) synchronize_rcu(); - for_each_online_cpu(i) - kfree(cachep->array[i]); - - /* NUMA: free the list3 structures */ - for_each_online_node(i) { - l3 = cachep->nodelists[i]; - if (l3) { - kfree(l3->shared); - free_alien_cache(l3->alien); - kfree(l3); - } - } - kmem_cache_free(&cache_cache, cachep); - unlock_cpu_hotplug(); - return 0; + __kmem_cache_destroy(cachep); + mutex_unlock(&cache_chain_mutex); } EXPORT_SYMBOL(kmem_cache_destroy); -/* Get the memory for a slab management obj. */ +/* + * Get the memory for a slab management obj. + * For a slab cache when the slab descriptor is off-slab, slab descriptors + * always come from malloc_sizes caches. The slab descriptor cannot + * come from the same cache which is getting created because, + * when we are searching for an appropriate cache for these + * descriptors in kmem_cache_create, we search through the malloc_sizes array. + * If we are creating a malloc_sizes cache here it would not be visible to + * kmem_find_general_cachep till the initialization is complete. + * Hence we cannot have slabp_cache same as the original cache. + */ static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp, int colour_off, gfp_t local_flags, int nodeid) @@ -2492,7 +2576,7 @@ static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp, if (OFF_SLAB(cachep)) { /* Slab management obj is off-slab. */ slabp = kmem_cache_alloc_node(cachep->slabp_cache, - local_flags, nodeid); + local_flags & ~GFP_THISNODE, nodeid); if (!slabp) return NULL; } else { @@ -2562,7 +2646,7 @@ static void cache_init_objs(struct kmem_cache *cachep, static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags) { - if (flags & SLAB_DMA) + if (flags & GFP_DMA) BUG_ON(!(cachep->gfpflags & GFP_DMA)); else BUG_ON(cachep->gfpflags & GFP_DMA); @@ -2633,10 +2717,10 @@ static void slab_map_pages(struct kmem_cache *cache, struct slab *slab, * Grow (by 1) the number of slabs within a cache. This is called by * kmem_cache_alloc() when there are no active objs left in a cache. */ -static int cache_grow(struct kmem_cache *cachep, gfp_t flags, int nodeid) +static int cache_grow(struct kmem_cache *cachep, + gfp_t flags, int nodeid, void *objp) { struct slab *slabp; - void *objp; size_t offset; gfp_t local_flags; unsigned long ctor_flags; @@ -2646,12 +2730,12 @@ static int cache_grow(struct kmem_cache *cachep, gfp_t flags, int nodeid) * Be lazy and only check for valid flags here, keeping it out of the * critical path in kmem_cache_alloc(). */ - BUG_ON(flags & ~(SLAB_DMA | SLAB_LEVEL_MASK | SLAB_NO_GROW)); - if (flags & SLAB_NO_GROW) + BUG_ON(flags & ~(GFP_DMA | GFP_LEVEL_MASK | __GFP_NO_GROW)); + if (flags & __GFP_NO_GROW) return 0; ctor_flags = SLAB_CTOR_CONSTRUCTOR; - local_flags = (flags & SLAB_LEVEL_MASK); + local_flags = (flags & GFP_LEVEL_MASK); if (!(local_flags & __GFP_WAIT)) /* * Not allowed to sleep. Need to tell a constructor about @@ -2688,12 +2772,14 @@ static int cache_grow(struct kmem_cache *cachep, gfp_t flags, int nodeid) * Get mem for the objs. Attempt to allocate a physical page from * 'nodeid'. */ - objp = kmem_getpages(cachep, flags, nodeid); + if (!objp) + objp = kmem_getpages(cachep, flags, nodeid); if (!objp) goto failed; /* Get slab management. */ - slabp = alloc_slabmgmt(cachep, objp, offset, local_flags, nodeid); + slabp = alloc_slabmgmt(cachep, objp, offset, + local_flags & ~GFP_THISNODE, nodeid); if (!slabp) goto opps1; @@ -2866,6 +2952,9 @@ static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags) int batchcount; struct kmem_list3 *l3; struct array_cache *ac; + int node; + + node = numa_node_id(); check_irq_off(); ac = cpu_cache_get(cachep); @@ -2879,7 +2968,7 @@ retry: */ batchcount = BATCHREFILL_LIMIT; } - l3 = cachep->nodelists[numa_node_id()]; + l3 = cachep->nodelists[node]; BUG_ON(ac->avail > 0 || !l3); spin_lock(&l3->list_lock); @@ -2909,7 +2998,7 @@ retry: STATS_SET_HIGH(cachep); ac->entry[ac->avail++] = slab_get_obj(cachep, slabp, - numa_node_id()); + node); } check_slabp(cachep, slabp); @@ -2928,7 +3017,7 @@ alloc_done: if (unlikely(!ac->avail)) { int x; - x = cache_grow(cachep, flags, numa_node_id()); + x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL); /* cache_grow can reenable interrupts, then ac could change. */ ac = cpu_cache_get(cachep); @@ -3004,26 +3093,101 @@ static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep, cachep->ctor(objp, cachep, ctor_flags); } +#if ARCH_SLAB_MINALIGN + if ((u32)objp & (ARCH_SLAB_MINALIGN-1)) { + printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n", + objp, ARCH_SLAB_MINALIGN); + } +#endif return objp; } #else #define cache_alloc_debugcheck_after(a,b,objp,d) (objp) #endif +#ifdef CONFIG_FAILSLAB + +static struct failslab_attr { + + struct fault_attr attr; + + u32 ignore_gfp_wait; +#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS + struct dentry *ignore_gfp_wait_file; +#endif + +} failslab = { + .attr = FAULT_ATTR_INITIALIZER, + .ignore_gfp_wait = 1, +}; + +static int __init setup_failslab(char *str) +{ + return setup_fault_attr(&failslab.attr, str); +} +__setup("failslab=", setup_failslab); + +static int should_failslab(struct kmem_cache *cachep, gfp_t flags) +{ + if (cachep == &cache_cache) + return 0; + if (flags & __GFP_NOFAIL) + return 0; + if (failslab.ignore_gfp_wait && (flags & __GFP_WAIT)) + return 0; + + return should_fail(&failslab.attr, obj_size(cachep)); +} + +#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS + +static int __init failslab_debugfs(void) +{ + mode_t mode = S_IFREG | S_IRUSR | S_IWUSR; + struct dentry *dir; + int err; + + err = init_fault_attr_dentries(&failslab.attr, "failslab"); + if (err) + return err; + dir = failslab.attr.dentries.dir; + + failslab.ignore_gfp_wait_file = + debugfs_create_bool("ignore-gfp-wait", mode, dir, + &failslab.ignore_gfp_wait); + + if (!failslab.ignore_gfp_wait_file) { + err = -ENOMEM; + debugfs_remove(failslab.ignore_gfp_wait_file); + cleanup_fault_attr_dentries(&failslab.attr); + } + + return err; +} + +late_initcall(failslab_debugfs); + +#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ + +#else /* CONFIG_FAILSLAB */ + +static inline int should_failslab(struct kmem_cache *cachep, gfp_t flags) +{ + return 0; +} + +#endif /* CONFIG_FAILSLAB */ + static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) { void *objp; struct array_cache *ac; -#ifdef CONFIG_NUMA - if (unlikely(current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) { - objp = alternate_node_alloc(cachep, flags); - if (objp != NULL) - return objp; - } -#endif - check_irq_off(); + + if (should_failslab(cachep, flags)) + return NULL; + ac = cpu_cache_get(cachep); if (likely(ac->avail)) { STATS_INC_ALLOCHIT(cachep); @@ -3040,12 +3204,26 @@ static __always_inline void *__cache_alloc(struct kmem_cache *cachep, gfp_t flags, void *caller) { unsigned long save_flags; - void *objp; + void *objp = NULL; cache_alloc_debugcheck_before(cachep, flags); local_irq_save(save_flags); - objp = ____cache_alloc(cachep, flags); + + if (unlikely(NUMA_BUILD && + current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) + objp = alternate_node_alloc(cachep, flags); + + if (!objp) + objp = ____cache_alloc(cachep, flags); + /* + * We may just have run out of memory on the local node. + * ____cache_alloc_node() knows how to locate memory on other nodes + */ + if (NUMA_BUILD && !objp) + objp = ____cache_alloc_node(cachep, flags, numa_node_id()); + + vx_slab_alloc(cachep, flags); local_irq_restore(save_flags); objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller); @@ -3064,7 +3242,7 @@ static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags) { int nid_alloc, nid_here; - if (in_interrupt()) + if (in_interrupt() || (flags & __GFP_THISNODE)) return NULL; nid_alloc = nid_here = numa_node_id(); if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD)) @@ -3072,14 +3250,83 @@ static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags) else if (current->mempolicy) nid_alloc = slab_node(current->mempolicy); if (nid_alloc != nid_here) - return __cache_alloc_node(cachep, flags, nid_alloc); + return ____cache_alloc_node(cachep, flags, nid_alloc); return NULL; } +/* + * Fallback function if there was no memory available and no objects on a + * certain node and fall back is permitted. First we scan all the + * available nodelists for available objects. If that fails then we + * perform an allocation without specifying a node. This allows the page + * allocator to do its reclaim / fallback magic. We then insert the + * slab into the proper nodelist and then allocate from it. + */ +void *fallback_alloc(struct kmem_cache *cache, gfp_t flags) +{ + struct zonelist *zonelist = &NODE_DATA(slab_node(current->mempolicy)) + ->node_zonelists[gfp_zone(flags)]; + struct zone **z; + void *obj = NULL; + int nid; + gfp_t local_flags = (flags & GFP_LEVEL_MASK); + +retry: + /* + * Look through allowed nodes for objects available + * from existing per node queues. + */ + for (z = zonelist->zones; *z && !obj; z++) { + nid = zone_to_nid(*z); + + if (cpuset_zone_allowed_hardwall(*z, flags) && + cache->nodelists[nid] && + cache->nodelists[nid]->free_objects) + obj = ____cache_alloc_node(cache, + flags | GFP_THISNODE, nid); + } + + if (!obj && !(flags & __GFP_NO_GROW)) { + /* + * This allocation will be performed within the constraints + * of the current cpuset / memory policy requirements. + * We may trigger various forms of reclaim on the allowed + * set and go into memory reserves if necessary. + */ + if (local_flags & __GFP_WAIT) + local_irq_enable(); + kmem_flagcheck(cache, flags); + obj = kmem_getpages(cache, flags, -1); + if (local_flags & __GFP_WAIT) + local_irq_disable(); + if (obj) { + /* + * Insert into the appropriate per node queues + */ + nid = page_to_nid(virt_to_page(obj)); + if (cache_grow(cache, flags, nid, obj)) { + obj = ____cache_alloc_node(cache, + flags | GFP_THISNODE, nid); + if (!obj) + /* + * Another processor may allocate the + * objects in the slab since we are + * not holding any locks. + */ + goto retry; + } else { + /* cache_grow already freed obj */ + obj = NULL; + } + } + } + return obj; +} + /* * A interface to enable slab creation on nodeid */ -static void *__cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, +static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid) { struct list_head *entry; @@ -3114,6 +3361,7 @@ retry: obj = slab_get_obj(cachep, slabp, nodeid); check_slabp(cachep, slabp); + vx_slab_alloc(cachep, flags); l3->free_objects--; /* move slabp to correct slabp list: */ list_del(&slabp->list); @@ -3128,12 +3376,16 @@ retry: must_grow: spin_unlock(&l3->list_lock); - x = cache_grow(cachep, flags, nodeid); + x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL); + if (x) + goto retry; - if (!x) - return NULL; + if (!(flags & __GFP_THISNODE)) + /* Unable to grow the cache. Fall back to other nodes. */ + return fallback_alloc(cachep, flags); + + return NULL; - goto retry; done: return obj; } @@ -3166,6 +3418,12 @@ static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects, if (slabp->inuse == 0) { if (l3->free_objects > l3->free_limit) { l3->free_objects -= cachep->num; + /* No need to drop any previously held + * lock here, even if we have a off-slab slab + * descriptor it is guaranteed to come from + * a different cache, refer to comments before + * alloc_slabmgmt. + */ slab_destroy(cachep, slabp); } else { list_add(&slabp->list, &l3->slabs_free); @@ -3241,6 +3499,7 @@ static inline void __cache_free(struct kmem_cache *cachep, void *objp) check_irq_off(); objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0)); + vx_slab_free(cachep); if (cache_free_alien(cachep, objp)) return; @@ -3301,7 +3560,7 @@ EXPORT_SYMBOL(kmem_cache_zalloc); * * Currently only used for dentry validation. */ -int fastcall kmem_ptr_validate(struct kmem_cache *cachep, void *ptr) +int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr) { unsigned long addr = (unsigned long)ptr; unsigned long min_addr = PAGE_OFFSET; @@ -3335,36 +3594,61 @@ out: * @cachep: The cache to allocate from. * @flags: See kmalloc(). * @nodeid: node number of the target node. + * @caller: return address of caller, used for debug information + * + * Identical to kmem_cache_alloc but it will allocate memory on the given + * node, which can improve the performance for cpu bound structures. * - * Identical to kmem_cache_alloc, except that this function is slow - * and can sleep. And it will allocate memory on the given node, which - * can improve the performance for cpu bound structures. - * New and improved: it will now make sure that the object gets - * put on the correct node list so that there is no false sharing. + * Fallback to other node is possible if __GFP_THISNODE is not set. */ -void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid) +static __always_inline void * +__cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, + int nodeid, void *caller) { unsigned long save_flags; - void *ptr; + void *ptr = NULL; cache_alloc_debugcheck_before(cachep, flags); local_irq_save(save_flags); - if (nodeid == -1 || nodeid == numa_node_id() || - !cachep->nodelists[nodeid]) - ptr = ____cache_alloc(cachep, flags); - else - ptr = __cache_alloc_node(cachep, flags, nodeid); - local_irq_restore(save_flags); + if (unlikely(nodeid == -1)) + nodeid = numa_node_id(); + + if (likely(cachep->nodelists[nodeid])) { + if (nodeid == numa_node_id()) { + /* + * Use the locally cached objects if possible. + * However ____cache_alloc does not allow fallback + * to other nodes. It may fail while we still have + * objects on other nodes available. + */ + ptr = ____cache_alloc(cachep, flags); + } + if (!ptr) { + /* ___cache_alloc_node can fall back to other nodes */ + ptr = ____cache_alloc_node(cachep, flags, nodeid); + } + } else { + /* Node not bootstrapped yet */ + if (!(flags & __GFP_THISNODE)) + ptr = fallback_alloc(cachep, flags); + } - ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, - __builtin_return_address(0)); + local_irq_restore(save_flags); + ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller); return ptr; } + +void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid) +{ + return __cache_alloc_node(cachep, flags, nodeid, + __builtin_return_address(0)); +} EXPORT_SYMBOL(kmem_cache_alloc_node); -void *kmalloc_node(size_t size, gfp_t flags, int node) +static __always_inline void * +__do_kmalloc_node(size_t size, gfp_t flags, int node, void *caller) { struct kmem_cache *cachep; @@ -3373,8 +3657,29 @@ void *kmalloc_node(size_t size, gfp_t flags, int node) return NULL; return kmem_cache_alloc_node(cachep, flags, node); } -EXPORT_SYMBOL(kmalloc_node); -#endif + +#ifdef CONFIG_DEBUG_SLAB +void *__kmalloc_node(size_t size, gfp_t flags, int node) +{ + return __do_kmalloc_node(size, flags, node, + __builtin_return_address(0)); +} +EXPORT_SYMBOL(__kmalloc_node); + +void *__kmalloc_node_track_caller(size_t size, gfp_t flags, + int node, void *caller) +{ + return __do_kmalloc_node(size, flags, node, caller); +} +EXPORT_SYMBOL(__kmalloc_node_track_caller); +#else +void *__kmalloc_node(size_t size, gfp_t flags, int node) +{ + return __do_kmalloc_node(size, flags, node, NULL); +} +EXPORT_SYMBOL(__kmalloc_node); +#endif /* CONFIG_DEBUG_SLAB */ +#endif /* CONFIG_NUMA */ /** * __do_kmalloc - allocate memory @@ -3399,71 +3704,25 @@ static __always_inline void *__do_kmalloc(size_t size, gfp_t flags, } +#ifdef CONFIG_DEBUG_SLAB void *__kmalloc(size_t size, gfp_t flags) { -#ifndef CONFIG_DEBUG_SLAB - return __do_kmalloc(size, flags, NULL); -#else return __do_kmalloc(size, flags, __builtin_return_address(0)); -#endif } EXPORT_SYMBOL(__kmalloc); -#ifdef CONFIG_DEBUG_SLAB void *__kmalloc_track_caller(size_t size, gfp_t flags, void *caller) { return __do_kmalloc(size, flags, caller); } EXPORT_SYMBOL(__kmalloc_track_caller); -#endif -#ifdef CONFIG_SMP -/** - * __alloc_percpu - allocate one copy of the object for every present - * cpu in the system, zeroing them. - * Objects should be dereferenced using the per_cpu_ptr macro only. - * - * @size: how many bytes of memory are required. - */ -void *__alloc_percpu(size_t size) +#else +void *__kmalloc(size_t size, gfp_t flags) { - int i; - struct percpu_data *pdata = kmalloc(sizeof(*pdata), GFP_KERNEL); - - if (!pdata) - return NULL; - - /* - * Cannot use for_each_online_cpu since a cpu may come online - * and we have no way of figuring out how to fix the array - * that we have allocated then.... - */ - for_each_possible_cpu(i) { - int node = cpu_to_node(i); - - if (node_online(node)) - pdata->ptrs[i] = kmalloc_node(size, GFP_KERNEL, node); - else - pdata->ptrs[i] = kmalloc(size, GFP_KERNEL); - - if (!pdata->ptrs[i]) - goto unwind_oom; - memset(pdata->ptrs[i], 0, size); - } - - /* Catch derefs w/o wrappers */ - return (void *)(~(unsigned long)pdata); - -unwind_oom: - while (--i >= 0) { - if (!cpu_possible(i)) - continue; - kfree(pdata->ptrs[i]); - } - kfree(pdata); - return NULL; + return __do_kmalloc(size, flags, NULL); } -EXPORT_SYMBOL(__alloc_percpu); +EXPORT_SYMBOL(__kmalloc); #endif /** @@ -3511,29 +3770,6 @@ void kfree(const void *objp) } EXPORT_SYMBOL(kfree); -#ifdef CONFIG_SMP -/** - * free_percpu - free previously allocated percpu memory - * @objp: pointer returned by alloc_percpu. - * - * Don't free memory not originally allocated by alloc_percpu() - * The complemented objp is to check for that. - */ -void free_percpu(const void *objp) -{ - int i; - struct percpu_data *p = (struct percpu_data *)(~(unsigned long)objp); - - /* - * We allocate for all cpus so we cannot use for online cpu here. - */ - for_each_possible_cpu(i) - kfree(p->ptrs[i]); - kfree(p); -} -EXPORT_SYMBOL(free_percpu); -#endif - unsigned int kmem_cache_size(struct kmem_cache *cachep) { return obj_size(cachep); @@ -3554,13 +3790,15 @@ static int alloc_kmemlist(struct kmem_cache *cachep) int node; struct kmem_list3 *l3; struct array_cache *new_shared; - struct array_cache **new_alien; + struct array_cache **new_alien = NULL; for_each_online_node(node) { - new_alien = alloc_alien_cache(node, cachep->limit); - if (!new_alien) - goto fail; + if (use_alien_caches) { + new_alien = alloc_alien_cache(node, cachep->limit); + if (!new_alien) + goto fail; + } new_shared = alloc_arraycache(node, cachep->shared*cachep->batchcount, @@ -3650,22 +3888,26 @@ static void do_ccupdate_local(void *info) static int do_tune_cpucache(struct kmem_cache *cachep, int limit, int batchcount, int shared) { - struct ccupdate_struct new; - int i, err; + struct ccupdate_struct *new; + int i; + + new = kzalloc(sizeof(*new), GFP_KERNEL); + if (!new) + return -ENOMEM; - memset(&new.new, 0, sizeof(new.new)); for_each_online_cpu(i) { - new.new[i] = alloc_arraycache(cpu_to_node(i), limit, + new->new[i] = alloc_arraycache(cpu_to_node(i), limit, batchcount); - if (!new.new[i]) { + if (!new->new[i]) { for (i--; i >= 0; i--) - kfree(new.new[i]); + kfree(new->new[i]); + kfree(new); return -ENOMEM; } } - new.cachep = cachep; + new->cachep = cachep; - on_each_cpu(do_ccupdate_local, (void *)&new, 1, 1); + on_each_cpu(do_ccupdate_local, (void *)new, 1, 1); check_irq_on(); cachep->batchcount = batchcount; @@ -3673,7 +3915,7 @@ static int do_tune_cpucache(struct kmem_cache *cachep, int limit, cachep->shared = shared; for_each_online_cpu(i) { - struct array_cache *ccold = new.new[i]; + struct array_cache *ccold = new->new[i]; if (!ccold) continue; spin_lock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock); @@ -3681,18 +3923,12 @@ static int do_tune_cpucache(struct kmem_cache *cachep, int limit, spin_unlock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock); kfree(ccold); } - - err = alloc_kmemlist(cachep); - if (err) { - printk(KERN_ERR "alloc_kmemlist failed for %s, error %d.\n", - cachep->name, -err); - BUG(); - } - return 0; + kfree(new); + return alloc_kmemlist(cachep); } /* Called with cache_chain_mutex held always */ -static void enable_cpucache(struct kmem_cache *cachep) +static int enable_cpucache(struct kmem_cache *cachep) { int err; int limit, shared; @@ -3744,6 +3980,7 @@ static void enable_cpucache(struct kmem_cache *cachep) if (err) printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n", cachep->name, -err); + return err; } /* @@ -3787,7 +4024,7 @@ void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3, * If we cannot acquire the cache chain mutex then just give up - we'll try * again on the next iteration. */ -static void cache_reap(void *unused) +static void cache_reap(struct work_struct *unused) { struct kmem_cache *searchp; struct kmem_list3 *l3; @@ -3796,7 +4033,7 @@ static void cache_reap(void *unused) if (!mutex_trylock(&cache_chain_mutex)) { /* Give up. Setup the next iteration. */ schedule_delayed_work(&__get_cpu_var(reap_work), - REAPTIMEOUT_CPUC); + round_jiffies_relative(REAPTIMEOUT_CPUC)); return; } @@ -3842,7 +4079,8 @@ next: next_reap_node(); refresh_cpu_vm_stats(smp_processor_id()); /* Set up the next iteration */ - schedule_delayed_work(&__get_cpu_var(reap_work), REAPTIMEOUT_CPUC); + schedule_delayed_work(&__get_cpu_var(reap_work), + round_jiffies_relative(REAPTIMEOUT_CPUC)); } #ifdef CONFIG_PROC_FS @@ -4010,7 +4248,7 @@ static int s_show(struct seq_file *m, void *p) * + further values on SMP and with statistics enabled */ -struct seq_operations slabinfo_op = { +const struct seq_operations slabinfo_op = { .start = s_start, .next = s_next, .stop = s_stop, @@ -4204,10 +4442,11 @@ static int leaks_show(struct seq_file *m, void *p) show_symbol(m, n[2*i+2]); seq_putc(m, '\n'); } + return 0; } -struct seq_operations slabstats_op = { +const struct seq_operations slabstats_op = { .start = leaks_start, .next = s_next, .stop = s_stop,