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Diffstat (limited to 'mm/slab.c')
| -rw-r--r-- | mm/slab.c | 4501 |
1 files changed, 0 insertions, 4501 deletions
diff --git a/mm/slab.c b/mm/slab.c deleted file mode 100644 index 35cb0c861508..000000000000 --- a/mm/slab.c +++ /dev/null @@ -1,4501 +0,0 @@ -/* - * linux/mm/slab.c - * Written by Mark Hemment, 1996/97. - * (markhe@nextd.demon.co.uk) - * - * kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli - * - * Major cleanup, different bufctl logic, per-cpu arrays - * (c) 2000 Manfred Spraul - * - * Cleanup, make the head arrays unconditional, preparation for NUMA - * (c) 2002 Manfred Spraul - * - * An implementation of the Slab Allocator as described in outline in; - * UNIX Internals: The New Frontiers by Uresh Vahalia - * Pub: Prentice Hall ISBN 0-13-101908-2 - * or with a little more detail in; - * The Slab Allocator: An Object-Caching Kernel Memory Allocator - * Jeff Bonwick (Sun Microsystems). - * Presented at: USENIX Summer 1994 Technical Conference - * - * The memory is organized in caches, one cache for each object type. - * (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct) - * Each cache consists out of many slabs (they are small (usually one - * page long) and always contiguous), and each slab contains multiple - * initialized objects. - * - * This means, that your constructor is used only for newly allocated - * slabs and you must pass objects with the same initializations to - * kmem_cache_free. - * - * Each cache can only support one memory type (GFP_DMA, GFP_HIGHMEM, - * normal). If you need a special memory type, then must create a new - * cache for that memory type. - * - * In order to reduce fragmentation, the slabs are sorted in 3 groups: - * full slabs with 0 free objects - * partial slabs - * empty slabs with no allocated objects - * - * If partial slabs exist, then new allocations come from these slabs, - * otherwise from empty slabs or new slabs are allocated. - * - * kmem_cache_destroy() CAN CRASH if you try to allocate from the cache - * during kmem_cache_destroy(). The caller must prevent concurrent allocs. - * - * Each cache has a short per-cpu head array, most allocs - * and frees go into that array, and if that array overflows, then 1/2 - * of the entries in the array are given back into the global cache. - * The head array is strictly LIFO and should improve the cache hit rates. - * On SMP, it additionally reduces the spinlock operations. - * - * The c_cpuarray may not be read with enabled local interrupts - - * it's changed with a smp_call_function(). - * - * SMP synchronization: - * constructors and destructors are called without any locking. - * Several members in struct kmem_cache and struct slab never change, they - * are accessed without any locking. - * The per-cpu arrays are never accessed from the wrong cpu, no locking, - * and local interrupts are disabled so slab code is preempt-safe. - * The non-constant members are protected with a per-cache irq spinlock. - * - * Many thanks to Mark Hemment, who wrote another per-cpu slab patch - * in 2000 - many ideas in the current implementation are derived from - * his patch. - * - * Further notes from the original documentation: - * - * 11 April '97. Started multi-threading - markhe - * The global cache-chain is protected by the mutex 'slab_mutex'. - * The sem is only needed when accessing/extending the cache-chain, which - * can never happen inside an interrupt (kmem_cache_create(), - * kmem_cache_shrink() and kmem_cache_reap()). - * - * At present, each engine can be growing a cache. This should be blocked. - * - * 15 March 2005. NUMA slab allocator. - * Shai Fultheim <shai@scalex86.org>. - * Shobhit Dayal <shobhit@calsoftinc.com> - * Alok N Kataria <alokk@calsoftinc.com> - * Christoph Lameter <christoph@lameter.com> - * - * Modified the slab allocator to be node aware on NUMA systems. - * Each node has its own list of partial, free and full slabs. - * All object allocations for a node occur from node specific slab lists. - */ - -#include <linux/slab.h> -#include <linux/mm.h> -#include <linux/poison.h> -#include <linux/swap.h> -#include <linux/cache.h> -#include <linux/interrupt.h> -#include <linux/init.h> -#include <linux/compiler.h> -#include <linux/cpuset.h> -#include <linux/proc_fs.h> -#include <linux/seq_file.h> -#include <linux/notifier.h> -#include <linux/kallsyms.h> -#include <linux/cpu.h> -#include <linux/sysctl.h> -#include <linux/module.h> -#include <linux/rcupdate.h> -#include <linux/string.h> -#include <linux/uaccess.h> -#include <linux/nodemask.h> -#include <linux/kmemleak.h> -#include <linux/mempolicy.h> -#include <linux/mutex.h> -#include <linux/fault-inject.h> -#include <linux/rtmutex.h> -#include <linux/reciprocal_div.h> -#include <linux/debugobjects.h> -#include <linux/kmemcheck.h> -#include <linux/memory.h> -#include <linux/prefetch.h> - -#include <net/sock.h> - -#include <asm/cacheflush.h> -#include <asm/tlbflush.h> -#include <asm/page.h> - -#include <trace/events/kmem.h> - -#include "internal.h" - -#include "slab.h" - -/* - * DEBUG - 1 for kmem_cache_create() to honour; SLAB_RED_ZONE & SLAB_POISON. - * 0 for faster, smaller code (especially in the critical paths). - * - * STATS - 1 to collect stats for /proc/slabinfo. - * 0 for faster, smaller code (especially in the critical paths). - * - * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible) - */ - -#ifdef CONFIG_DEBUG_SLAB -#define DEBUG 1 -#define STATS 1 -#define FORCED_DEBUG 1 -#else -#define DEBUG 0 -#define STATS 0 -#define FORCED_DEBUG 0 -#endif - -/* Shouldn't this be in a header file somewhere? */ -#define BYTES_PER_WORD sizeof(void *) -#define REDZONE_ALIGN max(BYTES_PER_WORD, __alignof__(unsigned long long)) - -#ifndef ARCH_KMALLOC_FLAGS -#define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN -#endif - -/* - * true if a page was allocated from pfmemalloc reserves for network-based - * swap - */ -static bool pfmemalloc_active __read_mostly; - -/* - * kmem_bufctl_t: - * - * Bufctl's are used for linking objs within a slab - * linked offsets. - * - * This implementation relies on "struct page" for locating the cache & - * slab an object belongs to. - * This allows the bufctl structure to be small (one int), but limits - * the number of objects a slab (not a cache) can contain when off-slab - * bufctls are used. The limit is the size of the largest general cache - * that does not use off-slab slabs. - * For 32bit archs with 4 kB pages, is this 56. - * This is not serious, as it is only for large objects, when it is unwise - * to have too many per slab. - * Note: This limit can be raised by introducing a general cache whose size - * is less than 512 (PAGE_SIZE<<3), but greater than 256. - */ - -typedef unsigned int kmem_bufctl_t; -#define BUFCTL_END (((kmem_bufctl_t)(~0U))-0) -#define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1) -#define BUFCTL_ACTIVE (((kmem_bufctl_t)(~0U))-2) -#define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-3) - -/* - * struct slab_rcu - * - * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to - * arrange for kmem_freepages to be called via RCU. This is useful if - * we need to approach a kernel structure obliquely, from its address - * obtained without the usual locking. We can lock the structure to - * stabilize it and check it's still at the given address, only if we - * can be sure that the memory has not been meanwhile reused for some - * other kind of object (which our subsystem's lock might corrupt). - * - * rcu_read_lock before reading the address, then rcu_read_unlock after - * taking the spinlock within the structure expected at that address. - */ -struct slab_rcu { - struct rcu_head head; - struct kmem_cache *cachep; - void *addr; -}; - -/* - * struct slab - * - * Manages the objs in a slab. Placed either at the beginning of mem allocated - * for a slab, or allocated from an general cache. - * Slabs are chained into three list: fully used, partial, fully free slabs. - */ -struct slab { - union { - struct { - struct list_head list; - unsigned long colouroff; - void *s_mem; /* including colour offset */ - unsigned int inuse; /* num of objs active in slab */ - kmem_bufctl_t free; - unsigned short nodeid; - }; - struct slab_rcu __slab_cover_slab_rcu; - }; -}; - -/* - * struct array_cache - * - * Purpose: - * - LIFO ordering, to hand out cache-warm objects from _alloc - * - reduce the number of linked list operations - * - reduce spinlock operations - * - * The limit is stored in the per-cpu structure to reduce the data cache - * footprint. - * - */ -struct array_cache { - unsigned int avail; - unsigned int limit; - unsigned int batchcount; - unsigned int touched; - spinlock_t lock; - void *entry[]; /* - * Must have this definition in here for the proper - * alignment of array_cache. Also simplifies accessing - * the entries. - * - * Entries should not be directly dereferenced as - * entries belonging to slabs marked pfmemalloc will - * have the lower bits set SLAB_OBJ_PFMEMALLOC - */ -}; - -#define SLAB_OBJ_PFMEMALLOC 1 -static inline bool is_obj_pfmemalloc(void *objp) -{ - return (unsigned long)objp & SLAB_OBJ_PFMEMALLOC; -} - -static inline void set_obj_pfmemalloc(void **objp) -{ - *objp = (void *)((unsigned long)*objp | SLAB_OBJ_PFMEMALLOC); - return; -} - -static inline void clear_obj_pfmemalloc(void **objp) -{ - *objp = (void *)((unsigned long)*objp & ~SLAB_OBJ_PFMEMALLOC); -} - -/* - * bootstrap: The caches do not work without cpuarrays anymore, but the - * cpuarrays are allocated from the generic caches... - */ -#define BOOT_CPUCACHE_ENTRIES 1 -struct arraycache_init { - struct array_cache cache; - void *entries[BOOT_CPUCACHE_ENTRIES]; -}; - -/* - * Need this for bootstrapping a per node allocator. - */ -#define NUM_INIT_LISTS (3 * MAX_NUMNODES) -static struct kmem_cache_node __initdata init_kmem_cache_node[NUM_INIT_LISTS]; -#define CACHE_CACHE 0 -#define SIZE_AC MAX_NUMNODES -#define SIZE_NODE (2 * MAX_NUMNODES) - -static int drain_freelist(struct kmem_cache *cache, - struct kmem_cache_node *n, int tofree); -static void free_block(struct kmem_cache *cachep, void **objpp, int len, - int node); -static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp); -static void cache_reap(struct work_struct *unused); - -static int slab_early_init = 1; - -#define INDEX_AC kmalloc_index(sizeof(struct arraycache_init)) -#define INDEX_NODE kmalloc_index(sizeof(struct kmem_cache_node)) - -static void kmem_cache_node_init(struct kmem_cache_node *parent) -{ - INIT_LIST_HEAD(&parent->slabs_full); - INIT_LIST_HEAD(&parent->slabs_partial); - INIT_LIST_HEAD(&parent->slabs_free); - parent->shared = NULL; - parent->alien = NULL; - parent->colour_next = 0; - spin_lock_init(&parent->list_lock); - parent->free_objects = 0; - parent->free_touched = 0; -} - -#define MAKE_LIST(cachep, listp, slab, nodeid) \ - do { \ - INIT_LIST_HEAD(listp); \ - list_splice(&(cachep->node[nodeid]->slab), listp); \ - } while (0) - -#define MAKE_ALL_LISTS(cachep, ptr, nodeid) \ - do { \ - MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \ - MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \ - MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \ - } while (0) - -#define CFLGS_OFF_SLAB (0x80000000UL) -#define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB) - -#define BATCHREFILL_LIMIT 16 -/* - * Optimization question: fewer reaps means less probability for unnessary - * cpucache drain/refill cycles. - * - * OTOH the cpuarrays can contain lots of objects, - * which could lock up otherwise freeable slabs. - */ -#define REAPTIMEOUT_CPUC (2*HZ) -#define REAPTIMEOUT_LIST3 (4*HZ) - -#if STATS -#define STATS_INC_ACTIVE(x) ((x)->num_active++) -#define STATS_DEC_ACTIVE(x) ((x)->num_active--) -#define STATS_INC_ALLOCED(x) ((x)->num_allocations++) -#define STATS_INC_GROWN(x) ((x)->grown++) -#define STATS_ADD_REAPED(x,y) ((x)->reaped += (y)) -#define STATS_SET_HIGH(x) \ - do { \ - if ((x)->num_active > (x)->high_mark) \ - (x)->high_mark = (x)->num_active; \ - } while (0) -#define STATS_INC_ERR(x) ((x)->errors++) -#define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++) -#define STATS_INC_NODEFREES(x) ((x)->node_frees++) -#define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++) -#define STATS_SET_FREEABLE(x, i) \ - do { \ - if ((x)->max_freeable < i) \ - (x)->max_freeable = i; \ - } while (0) -#define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit) -#define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss) -#define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit) -#define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss) -#else -#define STATS_INC_ACTIVE(x) do { } while (0) -#define STATS_DEC_ACTIVE(x) do { } while (0) -#define STATS_INC_ALLOCED(x) do { } while (0) -#define STATS_INC_GROWN(x) do { } while (0) -#define STATS_ADD_REAPED(x,y) do { (void)(y); } while (0) -#define STATS_SET_HIGH(x) do { } while (0) -#define STATS_INC_ERR(x) do { } while (0) -#define STATS_INC_NODEALLOCS(x) do { } while (0) -#define STATS_INC_NODEFREES(x) do { } while (0) -#define STATS_INC_ACOVERFLOW(x) do { } while (0) -#define STATS_SET_FREEABLE(x, i) do { } while (0) -#define STATS_INC_ALLOCHIT(x) do { } while (0) -#define STATS_INC_ALLOCMISS(x) do { } while (0) -#define STATS_INC_FREEHIT(x) do { } while (0) -#define STATS_INC_FREEMISS(x) do { } while (0) -#endif - -#if DEBUG - -/* - * memory layout of objects: - * 0 : objp - * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that - * the end of an object is aligned with the end of the real - * allocation. Catches writes behind the end of the allocation. - * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1: - * redzone word. - * cachep->obj_offset: The real object. - * cachep->size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long] - * cachep->size - 1* BYTES_PER_WORD: last caller address - * [BYTES_PER_WORD long] - */ -static int obj_offset(struct kmem_cache *cachep) -{ - return cachep->obj_offset; -} - -static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp) -{ - BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); - return (unsigned long long*) (objp + obj_offset(cachep) - - sizeof(unsigned long long)); -} - -static unsigned long long *dbg_redzone2(struct kmem_cache *cachep, void *objp) -{ - BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); - if (cachep->flags & SLAB_STORE_USER) - return (unsigned long long *)(objp + cachep->size - - sizeof(unsigned long long) - - REDZONE_ALIGN); - return (unsigned long long *) (objp + cachep->size - - sizeof(unsigned long long)); -} - -static void **dbg_userword(struct kmem_cache *cachep, void *objp) -{ - BUG_ON(!(cachep->flags & SLAB_STORE_USER)); - return (void **)(objp + cachep->size - BYTES_PER_WORD); -} - -#else - -#define obj_offset(x) 0 -#define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) -#define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) -#define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;}) - -#endif - -/* - * Do not go above this order unless 0 objects fit into the slab or - * overridden on the command line. - */ -#define SLAB_MAX_ORDER_HI 1 -#define SLAB_MAX_ORDER_LO 0 -static int slab_max_order = SLAB_MAX_ORDER_LO; -static bool slab_max_order_set __initdata; - -static inline struct kmem_cache *virt_to_cache(const void *obj) -{ - struct page *page = virt_to_head_page(obj); - return page->slab_cache; -} - -static inline struct slab *virt_to_slab(const void *obj) -{ - struct page *page = virt_to_head_page(obj); - - VM_BUG_ON(!PageSlab(page)); - return page->slab_page; -} - -static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab, - unsigned int idx) -{ - return slab->s_mem + cache->size * idx; -} - -/* - * We want to avoid an expensive divide : (offset / cache->size) - * Using the fact that size is a constant for a particular cache, - * we can replace (offset / cache->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) -{ - u32 offset = (obj - slab->s_mem); - return reciprocal_divide(offset, cache->reciprocal_buffer_size); -} - -static struct arraycache_init initarray_generic = - { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} }; - -/* internal cache of cache description objs */ -static struct kmem_cache kmem_cache_boot = { - .batchcount = 1, - .limit = BOOT_CPUCACHE_ENTRIES, - .shared = 1, - .size = sizeof(struct kmem_cache), - .name = "kmem_cache", -}; - -#define BAD_ALIEN_MAGIC 0x01020304ul - -#ifdef CONFIG_LOCKDEP - -/* - * Slab sometimes uses the kmalloc slabs to store the slab headers - * for other slabs "off slab". - * The locking for this is tricky in that it nests within the locks - * of all other slabs in a few places; to deal with this special - * locking we put on-slab caches into a separate lock-class. - * - * We set lock class for alien array caches which are up during init. - * The lock annotation will be lost if all cpus of a node goes down and - * then comes back up during hotplug - */ -static struct lock_class_key on_slab_l3_key; -static struct lock_class_key on_slab_alc_key; - -static struct lock_class_key debugobj_l3_key; -static struct lock_class_key debugobj_alc_key; - -static void slab_set_lock_classes(struct kmem_cache *cachep, - struct lock_class_key *l3_key, struct lock_class_key *alc_key, - int q) -{ - struct array_cache **alc; - struct kmem_cache_node *n; - int r; - - n = cachep->node[q]; - if (!n) - return; - - lockdep_set_class(&n->list_lock, l3_key); - alc = n->alien; - /* - * FIXME: This check for BAD_ALIEN_MAGIC - * should go away when common slab code is taught to - * work even without alien caches. - * Currently, non NUMA code returns BAD_ALIEN_MAGIC - * for alloc_alien_cache, - */ - if (!alc || (unsigned long)alc == BAD_ALIEN_MAGIC) - return; - for_each_node(r) { - if (alc[r]) - lockdep_set_class(&alc[r]->lock, alc_key); - } -} - -static void slab_set_debugobj_lock_classes_node(struct kmem_cache *cachep, int node) -{ - slab_set_lock_classes(cachep, &debugobj_l3_key, &debugobj_alc_key, node); -} - -static void slab_set_debugobj_lock_classes(struct kmem_cache *cachep) -{ - int node; - - for_each_online_node(node) - slab_set_debugobj_lock_classes_node(cachep, node); -} - -static void init_node_lock_keys(int q) -{ - int i; - - if (slab_state < UP) - return; - - for (i = 1; i <= KMALLOC_SHIFT_HIGH; i++) { - struct kmem_cache_node *n; - struct kmem_cache *cache = kmalloc_caches[i]; - - if (!cache) - continue; - - n = cache->node[q]; - if (!n || OFF_SLAB(cache)) - continue; - - slab_set_lock_classes(cache, &on_slab_l3_key, - &on_slab_alc_key, q); - } -} - -static void on_slab_lock_classes_node(struct kmem_cache *cachep, int q) -{ - if (!cachep->node[q]) - return; - - slab_set_lock_classes(cachep, &on_slab_l3_key, - &on_slab_alc_key, q); -} - -static inline void on_slab_lock_classes(struct kmem_cache *cachep) -{ - int node; - - VM_BUG_ON(OFF_SLAB(cachep)); - for_each_node(node) - on_slab_lock_classes_node(cachep, node); -} - -static inline void init_lock_keys(void) -{ - int node; - - for_each_node(node) - init_node_lock_keys(node); -} -#else -static void init_node_lock_keys(int q) -{ -} - -static inline void init_lock_keys(void) -{ -} - -static inline void on_slab_lock_classes(struct kmem_cache *cachep) -{ -} - -static inline void on_slab_lock_classes_node(struct kmem_cache *cachep, int node) -{ -} - -static void slab_set_debugobj_lock_classes_node(struct kmem_cache *cachep, int node) -{ -} - -static void slab_set_debugobj_lock_classes(struct kmem_cache *cachep) -{ -} -#endif - -static DEFINE_PER_CPU(struct delayed_work, slab_reap_work); - -static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep) -{ - return cachep->array[smp_processor_id()]; -} - -static size_t slab_mgmt_size(size_t nr_objs, size_t align) -{ - return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align); -} - -/* - * Calculate the number of objects and left-over bytes for a given buffer size. - */ -static void cache_estimate(unsigned long gfporder, size_t buffer_size, - size_t align, int flags, size_t *left_over, - unsigned int *num) -{ - int nr_objs; - size_t mgmt_size; - size_t slab_size = PAGE_SIZE << gfporder; - - /* - * The slab management structure can be either off the slab or - * on it. For the latter case, the memory allocated for a - * slab is used for: - * - * - The struct slab - * - One kmem_bufctl_t for each object - * - Padding to respect alignment of @align - * - @buffer_size bytes for each object - * - * If the slab management structure is off the slab, then the - * alignment will already be calculated into the size. Because - * the slabs are all pages aligned, the objects will be at the - * correct alignment when allocated. - */ - if (flags & CFLGS_OFF_SLAB) { - mgmt_size = 0; - nr_objs = slab_size / buffer_size; - - if (nr_objs > SLAB_LIMIT) - nr_objs = SLAB_LIMIT; - } else { - /* - * Ignore padding for the initial guess. The padding - * is at most @align-1 bytes, and @buffer_size is at - * least @align. In the worst case, this result will - * be one greater than the number of objects that fit - * into the memory allocation when taking the padding - * into account. - */ - nr_objs = (slab_size - sizeof(struct slab)) / - (buffer_size + sizeof(kmem_bufctl_t)); - - /* - * This calculated number will be either the right - * amount, or one greater than what we want. - */ - if (slab_mgmt_size(nr_objs, align) + nr_objs*buffer_size - > slab_size) - nr_objs--; - - if (nr_objs > SLAB_LIMIT) - nr_objs = SLAB_LIMIT; - - mgmt_size = slab_mgmt_size(nr_objs, align); - } - *num = nr_objs; - *left_over = slab_size - nr_objs*buffer_size - mgmt_size; -} - -#if DEBUG -#define slab_error(cachep, msg) __slab_error(__func__, cachep, msg) - -static void __slab_error(const char *function, struct kmem_cache *cachep, - char *msg) -{ - printk(KERN_ERR "slab error in %s(): cache `%s': %s\n", - function, cachep->name, msg); - dump_stack(); - add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); -} -#endif - -/* - * 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); - -static int __init slab_max_order_setup(char *str) -{ - get_option(&str, &slab_max_order); - slab_max_order = slab_max_order < 0 ? 0 : - min(slab_max_order, MAX_ORDER - 1); - slab_max_order_set = true; - - return 1; -} -__setup("slab_max_order=", slab_max_order_setup); - -#ifdef CONFIG_NUMA -/* - * Special reaping functions for NUMA systems called from cache_reap(). - * These take care of doing round robin flushing of alien caches (containing - * objects freed on different nodes from which they were allocated) and the - * flushing of remote pcps by calling drain_node_pages. - */ -static DEFINE_PER_CPU(unsigned long, slab_reap_node); - -static void init_reap_node(int cpu) -{ - int node; - - node = next_node(cpu_to_mem(cpu), node_online_map); - if (node == MAX_NUMNODES) - node = first_node(node_online_map); - - per_cpu(slab_reap_node, cpu) = node; -} - -static void next_reap_node(void) -{ - int node = __this_cpu_read(slab_reap_node); - - node = next_node(node, node_online_map); - if (unlikely(node >= MAX_NUMNODES)) - node = first_node(node_online_map); - __this_cpu_write(slab_reap_node, node); -} - -#else -#define init_reap_node(cpu) do { } while (0) -#define next_reap_node(void) do { } while (0) -#endif - -/* - * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz - * via the workqueue/eventd. - * Add the CPU number into the expiration time to minimize the possibility of - * the CPUs getting into lockstep and contending for the global cache chain - * lock. - */ -static void __cpuinit start_cpu_timer(int cpu) -{ - struct delayed_work *reap_work = &per_cpu(slab_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->work.func == NULL) { - init_reap_node(cpu); - INIT_DEFERRABLE_WORK(reap_work, cache_reap); - schedule_delayed_work_on(cpu, reap_work, - __round_jiffies_relative(HZ, cpu)); - } -} - -static struct array_cache *alloc_arraycache(int node, int entries, - int batchcount, gfp_t gfp) -{ - int memsize = sizeof(void *) * entries + sizeof(struct array_cache); - struct array_cache *nc = NULL; - - nc = kmalloc_node(memsize, gfp, node); - /* - * The array_cache structures contain pointers to free object. - * However, when such objects are allocated or transferred to another - * cache the pointers are not cleared and they could be counted as - * valid references during a kmemleak scan. Therefore, kmemleak must - * not scan such objects. - */ - kmemleak_no_scan(nc); - if (nc) { - nc->avail = 0; - nc->limit = entries; - nc->batchcount = batchcount; - nc->touched = 0; - spin_lock_init(&nc->lock); - } - return nc; -} - -static inline bool is_slab_pfmemalloc(struct slab *slabp) -{ - struct page *page = virt_to_page(slabp->s_mem); - - return PageSlabPfmemalloc(page); -} - -/* Clears pfmemalloc_active if no slabs have pfmalloc set */ -static void recheck_pfmemalloc_active(struct kmem_cache *cachep, - struct array_cache *ac) -{ - struct kmem_cache_node *n = cachep->node[numa_mem_id()]; - struct slab *slabp; - unsigned long flags; - - if (!pfmemalloc_active) - return; - - spin_lock_irqsave(&n->list_lock, flags); - list_for_each_entry(slabp, &n->slabs_full, list) - if (is_slab_pfmemalloc(slabp)) - goto out; - - list_for_each_entry(slabp, &n->slabs_partial, list) - if (is_slab_pfmemalloc(slabp)) - goto out; - - list_for_each_entry(slabp, &n->slabs_free, list) - if (is_slab_pfmemalloc(slabp)) - goto out; - - pfmemalloc_active = false; -out: - spin_unlock_irqrestore(&n->list_lock, flags); -} - -static void *__ac_get_obj(struct kmem_cache *cachep, struct array_cache *ac, - gfp_t flags, bool force_refill) -{ - int i; - void *objp = ac->entry[--ac->avail]; - - /* Ensure the caller is allowed to use objects from PFMEMALLOC slab */ - if (unlikely(is_obj_pfmemalloc(objp))) { - struct kmem_cache_node *n; - - if (gfp_pfmemalloc_allowed(flags)) { - clear_obj_pfmemalloc(&objp); - return objp; - } - - /* The caller cannot use PFMEMALLOC objects, find another one */ - for (i = 0; i < ac->avail; i++) { - /* If a !PFMEMALLOC object is found, swap them */ - if (!is_obj_pfmemalloc(ac->entry[i])) { - objp = ac->entry[i]; - ac->entry[i] = ac->entry[ac->avail]; - ac->entry[ac->avail] = objp; - return objp; - } - } - - /* - * If there are empty slabs on the slabs_free list and we are - * being forced to refill the cache, mark this one !pfmemalloc. - */ - n = cachep->node[numa_mem_id()]; - if (!list_empty(&n->slabs_free) && force_refill) { - struct slab *slabp = virt_to_slab(objp); - ClearPageSlabPfmemalloc(virt_to_head_page(slabp->s_mem)); - clear_obj_pfmemalloc(&objp); - recheck_pfmemalloc_active(cachep, ac); - return objp; - } - - /* No !PFMEMALLOC objects available */ - ac->avail++; - objp = NULL; - } - - return objp; -} - -static inline void *ac_get_obj(struct kmem_cache *cachep, - struct array_cache *ac, gfp_t flags, bool force_refill) -{ - void *objp; - - if (unlikely(sk_memalloc_socks())) - objp = __ac_get_obj(cachep, ac, flags, force_refill); - else - objp = ac->entry[--ac->avail]; - - return objp; -} - -static void *__ac_put_obj(struct kmem_cache *cachep, struct array_cache *ac, - void *objp) -{ - if (unlikely(pfmemalloc_active)) { - /* Some pfmemalloc slabs exist, check if this is one */ - struct page *page = virt_to_head_page(objp); - if (PageSlabPfmemalloc(page)) - set_obj_pfmemalloc(&objp); - } - - return objp; -} - -static inline void ac_put_obj(struct kmem_cache *cachep, struct array_cache *ac, - void *objp) -{ - if (unlikely(sk_memalloc_socks())) - objp = __ac_put_obj(cachep, ac, objp); - - ac->entry[ac->avail++] = objp; -} - -/* - * Transfer objects in one arraycache to another. - * Locking must be handled by the caller. - * - * Return the number of entries transferred. - */ -static int transfer_objects(struct array_cache *to, - struct array_cache *from, unsigned int max) -{ - /* Figure out how many entries to transfer */ - int nr = min3(from->avail, max, to->limit - to->avail); - - if (!nr) - return 0; - - memcpy(to->entry + to->avail, from->entry + from->avail -nr, - sizeof(void *) *nr); - - from->avail -= nr; - to->avail += nr; - return nr; -} - -#ifndef CONFIG_NUMA - -#define drain_alien_cache(cachep, alien) do { } while (0) -#define reap_alien(cachep, n) do { } while (0) - -static inline struct array_cache **alloc_alien_cache(int node, int limit, gfp_t gfp) -{ - 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, gfp_t gfp) -{ - struct array_cache **ac_ptr; - int memsize = sizeof(void *) * nr_node_ids; - int i; - - if (limit > 1) - limit = 12; - ac_ptr = kzalloc_node(memsize, gfp, node); - if (ac_ptr) { - for_each_node(i) { - if (i == node || !node_online(i)) - continue; - ac_ptr[i] = alloc_arraycache(node, limit, 0xbaadf00d, gfp); - if (!ac_ptr[i]) { - for (i--; i >= 0; i--) - kfree(ac_ptr[i]); - kfree(ac_ptr); - return NULL; - } - } - } - return ac_ptr; -} - -static void free_alien_cache(struct array_cache **ac_ptr) -{ - int i; - - if (!ac_ptr) - return; - for_each_node(i) - kfree(ac_ptr[i]); - kfree(ac_ptr); -} - -static void __drain_alien_cache(struct kmem_cache *cachep, - struct array_cache *ac, int node) -{ - struct kmem_cache_node *n = cachep->node[node]; - - if (ac->avail) { - spin_lock(&n->list_lock); - /* - * Stuff objects into the remote nodes shared array first. - * That way we could avoid the overhead of putting the objects - * into the free lists and getting them back later. - */ - if (n->shared) - transfer_objects(n->shared, ac, ac->limit); - - free_block(cachep, ac->entry, ac->avail, node); - ac->avail = 0; - spin_unlock(&n->list_lock); - } -} - -/* - * Called from cache_reap() to regularly drain alien caches round robin. - */ -static void reap_alien(struct kmem_cache *cachep, struct kmem_cache_node *n) -{ - int node = __this_cpu_read(slab_reap_node); - - if (n->alien) { - struct array_cache *ac = n->alien[node]; - - if (ac && ac->avail && spin_trylock_irq(&ac->lock)) { - __drain_alien_cache(cachep, ac, node); - spin_unlock_irq(&ac->lock); - } - } -} - -static void drain_alien_cache(struct kmem_cache *cachep, - struct array_cache **alien) -{ - int i = 0; - struct array_cache *ac; - unsigned long flags; - - for_each_online_node(i) { - ac = alien[i]; - if (ac) { - spin_lock_irqsave(&ac->lock, flags); - __drain_alien_cache(cachep, ac, i); - spin_unlock_irqrestore(&ac->lock, flags); - } - } -} - -static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) -{ - struct slab *slabp = virt_to_slab(objp); - int nodeid = slabp->nodeid; - struct kmem_cache_node *n; - struct array_cache *alien = NULL; - int node; - - node = numa_mem_id(); - - /* - * Make sure we are not freeing a object from another node to the array - * cache on this cpu. - */ - if (likely(slabp->nodeid == node)) - return 0; - - n = cachep->node[node]; - STATS_INC_NODEFREES(cachep); - if (n->alien && n->alien[nodeid]) { - alien = n->alien[nodeid]; - spin_lock(&alien->lock); - if (unlikely(alien->avail == alien->limit)) { - STATS_INC_ACOVERFLOW(cachep); - __drain_alien_cache(cachep, alien, nodeid); - } - ac_put_obj(cachep, alien, objp); - spin_unlock(&alien->lock); - } else { - spin_lock(&(cachep->node[nodeid])->list_lock); - free_block(cachep, &objp, 1, nodeid); - spin_unlock(&(cachep->node[nodeid])->list_lock); - } - return 1; -} -#endif - -/* - * Allocates and initializes node for a node on each slab cache, used for - * either memory or cpu hotplug. If memory is being hot-added, the kmem_cache_node - * will be allocated off-node since memory is not yet online for the new node. - * When hotplugging memory or a cpu, existing node are not replaced if - * already in use. - * - * Must hold slab_mutex. - */ -static int init_cache_node_node(int node) -{ - struct kmem_cache *cachep; - struct kmem_cache_node *n; - const int memsize = sizeof(struct kmem_cache_node); - - list_for_each_entry(cachep, &slab_caches, list) { - /* - * Set up the size64 kmemlist for cpu before we can - * begin anything. Make sure some other cpu on this - * node has not already allocated this - */ - if (!cachep->node[node]) { - n = kmalloc_node(memsize, GFP_KERNEL, node); - if (!n) - return -ENOMEM; - kmem_cache_node_init(n); - n->next_reap = jiffies + REAPTIMEOUT_LIST3 + - ((unsigned long)cachep) % REAPTIMEOUT_LIST3; - - /* - * The l3s don't come and go as CPUs come and - * go. slab_mutex is sufficient - * protection here. - */ - cachep->node[node] = n; - } - - spin_lock_irq(&cachep->node[node]->list_lock); - cachep->node[node]->free_limit = - (1 + nr_cpus_node(node)) * - cachep->batchcount + cachep->num; - spin_unlock_irq(&cachep->node[node]->list_lock); - } - return 0; -} - -static inline int slabs_tofree(struct kmem_cache *cachep, - struct kmem_cache_node *n) -{ - return (n->free_objects + cachep->num - 1) / cachep->num; -} - -static void __cpuinit cpuup_canceled(long cpu) -{ - struct kmem_cache *cachep; - struct kmem_cache_node *n = NULL; - int node = cpu_to_mem(cpu); - const struct cpumask *mask = cpumask_of_node(node); - - list_for_each_entry(cachep, &slab_caches, list) { - struct array_cache *nc; - struct array_cache *shared; - struct array_cache **alien; - - /* cpu is dead; no one can alloc from it. */ - nc = cachep->array[cpu]; - cachep->array[cpu] = NULL; - n = cachep->node[node]; - - if (!n) - goto free_array_cache; - - spin_lock_irq(&n->list_lock); - - /* Free limit for this kmem_cache_node */ - n->free_limit -= cachep->batchcount; - if (nc) - free_block(cachep, nc->entry, nc->avail, node); - - if (!cpumask_empty(mask)) { - spin_unlock_irq(&n->list_lock); - goto free_array_cache; - } - - shared = n->shared; - if (shared) { - free_block(cachep, shared->entry, - shared->avail, node); - n->shared = NULL; - } - - alien = n->alien; - n->alien = NULL; - - spin_unlock_irq(&n->list_lock); - - kfree(shared); - if (alien) { - drain_alien_cache(cachep, alien); - free_alien_cache(alien); - } -free_array_cache: - kfree(nc); - } - /* - * In the previous loop, all the objects were freed to - * the respective cache's slabs, now we can go ahead and - * shrink each nodelist to its limit. - */ - list_for_each_entry(cachep, &slab_caches, list) { - n = cachep->node[node]; - if (!n) - continue; - drain_freelist(cachep, n, slabs_tofree(cachep, n)); - } -} - -static int __cpuinit cpuup_prepare(long cpu) -{ - struct kmem_cache *cachep; - struct kmem_cache_node *n = NULL; - int node = cpu_to_mem(cpu); - int err; - - /* - * We need to do this right in the beginning since - * alloc_arraycache's are going to use this list. - * kmalloc_node allows us to add the slab to the right - * kmem_cache_node and not this cpu's kmem_cache_node - */ - err = init_cache_node_node(node); - if (err < 0) - goto bad; - - /* - * Now we can go ahead with allocating the shared arrays and - * array caches - */ - list_for_each_entry(cachep, &slab_caches, list) { - struct array_cache *nc; - struct array_cache *shared = NULL; - struct array_cache **alien = NULL; - - nc = alloc_arraycache(node, cachep->limit, - cachep->batchcount, GFP_KERNEL); - if (!nc) - goto bad; - if (cachep->shared) { - shared = alloc_arraycache(node, - cachep->shared * cachep->batchcount, - 0xbaadf00d, GFP_KERNEL); - if (!shared) { - kfree(nc); - goto bad; - } - } - if (use_alien_caches) { - alien = alloc_alien_cache(node, cachep->limit, GFP_KERNEL); - if (!alien) { - kfree(shared); - kfree(nc); - goto bad; - } - } - cachep->array[cpu] = nc; - n = cachep->node[node]; - BUG_ON(!n); - - spin_lock_irq(&n->list_lock); - if (!n->shared) { - /* - * We are serialised from CPU_DEAD or - * CPU_UP_CANCELLED by the cpucontrol lock - */ - n->shared = shared; - shared = NULL; - } -#ifdef CONFIG_NUMA - if (!n->alien) { - n->alien = alien; - alien = NULL; - } -#endif - spin_unlock_irq(&n->list_lock); - kfree(shared); - free_alien_cache(alien); - if (cachep->flags & SLAB_DEBUG_OBJECTS) - slab_set_debugobj_lock_classes_node(cachep, node); - else if (!OFF_SLAB(cachep) && - !(cachep->flags & SLAB_DESTROY_BY_RCU)) - on_slab_lock_classes_node(cachep, node); - } - init_node_lock_keys(node); - - return 0; -bad: - cpuup_canceled(cpu); - return -ENOMEM; -} - -static int __cpuinit cpuup_callback(struct notifier_block *nfb, - unsigned long action, void *hcpu) -{ - long cpu = (long)hcpu; - int err = 0; - - switch (action) { - case CPU_UP_PREPARE: - case CPU_UP_PREPARE_FROZEN: - mutex_lock(&slab_mutex); - err = cpuup_prepare(cpu); - mutex_unlock(&slab_mutex); - break; - case CPU_ONLINE: - case CPU_ONLINE_FROZEN: - start_cpu_timer(cpu); - break; -#ifdef CONFIG_HOTPLUG_CPU - case CPU_DOWN_PREPARE: - case CPU_DOWN_PREPARE_FROZEN: - /* - * Shutdown cache reaper. Note that the slab_mutex is - * held so that if cache_reap() is invoked it cannot do - * anything expensive but will only modify reap_work - * and reschedule the timer. - */ - cancel_delayed_work_sync(&per_cpu(slab_reap_work, cpu)); - /* Now the cache_reaper is guaranteed to be not running. */ - per_cpu(slab_reap_work, cpu).work.func = NULL; - break; - case CPU_DOWN_FAILED: - case CPU_DOWN_FAILED_FROZEN: - start_cpu_timer(cpu); - break; - case CPU_DEAD: - case CPU_DEAD_FROZEN: - /* - * Even if all the cpus of a node are down, we don't free the - * kmem_cache_node of any cache. This to avoid a race between - * cpu_down, and a kmalloc allocation from another cpu for - * memory from the node of the cpu going down. The node - * structure is usually allocated from kmem_cache_create() and - * gets destroyed at kmem_cache_destroy(). - */ - /* fall through */ -#endif - case CPU_UP_CANCELED: - case CPU_UP_CANCELED_FROZEN: - mutex_lock(&slab_mutex); - cpuup_canceled(cpu); - mutex_unlock(&slab_mutex); - break; - } - return notifier_from_errno(err); -} - -static struct notifier_block __cpuinitdata cpucache_notifier = { - &cpuup_callback, NULL, 0 -}; - -#if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG) -/* - * Drains freelist for a node on each slab cache, used for memory hot-remove. - * Returns -EBUSY if all objects cannot be drained so that the node is not - * removed. - * - * Must hold slab_mutex. - */ -static int __meminit drain_cache_node_node(int node) -{ - struct kmem_cache *cachep; - int ret = 0; - - list_for_each_entry(cachep, &slab_caches, list) { - struct kmem_cache_node *n; - - n = cachep->node[node]; - if (!n) - continue; - - drain_freelist(cachep, n, slabs_tofree(cachep, n)); - - if (!list_empty(&n->slabs_full) || - !list_empty(&n->slabs_partial)) { - ret = -EBUSY; - break; - } - } - return ret; -} - -static int __meminit slab_memory_callback(struct notifier_block *self, - unsigned long action, void *arg) -{ - struct memory_notify *mnb = arg; - int ret = 0; - int nid; - - nid = mnb->status_change_nid; - if (nid < 0) - goto out; - - switch (action) { - case MEM_GOING_ONLINE: - mutex_lock(&slab_mutex); - ret = init_cache_node_node(nid); - mutex_unlock(&slab_mutex); - break; - case MEM_GOING_OFFLINE: - mutex_lock(&slab_mutex); - ret = drain_cache_node_node(nid); - mutex_unlock(&slab_mutex); - break; - case MEM_ONLINE: - case MEM_OFFLINE: - case MEM_CANCEL_ONLINE: - case MEM_CANCEL_OFFLINE: - break; - } -out: - return notifier_from_errno(ret); -} -#endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */ - -/* - * swap the static kmem_cache_node with kmalloced memory - */ -static void __init init_list(struct kmem_cache *cachep, struct kmem_cache_node *list, - int nodeid) -{ - struct kmem_cache_node *ptr; - - ptr = kmalloc_node(sizeof(struct kmem_cache_node), GFP_NOWAIT, nodeid); - BUG_ON(!ptr); - - memcpy(ptr, list, sizeof(struct kmem_cache_node)); - /* - * Do not assume that spinlocks can be initialized via memcpy: - */ - spin_lock_init(&ptr->list_lock); - - MAKE_ALL_LISTS(cachep, ptr, nodeid); - cachep->node[nodeid] = ptr; -} - -/* - * For setting up all the kmem_cache_node for cache whose buffer_size is same as - * size of kmem_cache_node. - */ -static void __init set_up_node(struct kmem_cache *cachep, int index) -{ - int node; - - for_each_online_node(node) { - cachep->node[node] = &init_kmem_cache_node[index + node]; - cachep->node[node]->next_reap = jiffies + - REAPTIMEOUT_LIST3 + - ((unsigned long)cachep) % REAPTIMEOUT_LIST3; - } -} - -/* - * The memory after the last cpu cache pointer is used for the - * the node pointer. - */ -static void setup_node_pointer(struct kmem_cache *cachep) -{ - cachep->node = (struct kmem_cache_node **)&cachep->array[nr_cpu_ids]; -} - -/* - * Initialisation. Called after the page allocator have been initialised and - * before smp_init(). - */ -void __init kmem_cache_init(void) -{ - int i; - - kmem_cache = &kmem_cache_boot; - setup_node_pointer(kmem_cache); - - if (num_possible_nodes() == 1) - use_alien_caches = 0; - - for (i = 0; i < NUM_INIT_LISTS; i++) - kmem_cache_node_init(&init_kmem_cache_node[i]); - - set_up_node(kmem_cache, CACHE_CACHE); - - /* - * Fragmentation resistance on low memory - only use bigger - * page orders on machines with more than 32MB of memory if - * not overridden on the command line. - */ - if (!slab_max_order_set && totalram_pages > (32 << 20) >> PAGE_SHIFT) - slab_max_order = SLAB_MAX_ORDER_HI; - - /* Bootstrap is tricky, because several objects are allocated - * from caches that do not exist yet: - * 1) initialize the kmem_cache cache: it contains the struct - * kmem_cache structures of all caches, except kmem_cache itself: - * kmem_cache is statically allocated. - * Initially an __init data area is used for the head array and the - * kmem_cache_node structures, it's replaced with a kmalloc allocated - * array at the end of the bootstrap. - * 2) Create the first kmalloc cache. - * The struct kmem_cache for the new cache is allocated normally. - * An __init data area is used for the head array. - * 3) Create the remaining kmalloc caches, with minimally sized - * head arrays. - * 4) Replace the __init data head arrays for kmem_cache and the first - * kmalloc cache with kmalloc allocated arrays. - * 5) Replace the __init data for kmem_cache_node for kmem_cache and - * the other cache's with kmalloc allocated memory. - * 6) Resize the head arrays of the kmalloc caches to their final sizes. - */ - - /* 1) create the kmem_cache */ - - /* - * struct kmem_cache size depends on nr_node_ids & nr_cpu_ids - */ - create_boot_cache(kmem_cache, "kmem_cache", - offsetof(struct kmem_cache, array[nr_cpu_ids]) + - nr_node_ids * sizeof(struct kmem_cache_node *), - SLAB_HWCACHE_ALIGN); - list_add(&kmem_cache->list, &slab_caches); - - /* 2+3) create the kmalloc caches */ - - /* - * Initialize the caches that provide memory for the array cache and the - * kmem_cache_node structures first. Without this, further allocations will - * bug. - */ - - kmalloc_caches[INDEX_AC] = create_kmalloc_cache("kmalloc-ac", - kmalloc_size(INDEX_AC), ARCH_KMALLOC_FLAGS); - - if (INDEX_AC != INDEX_NODE) - kmalloc_caches[INDEX_NODE] = - create_kmalloc_cache("kmalloc-node", - kmalloc_size(INDEX_NODE), ARCH_KMALLOC_FLAGS); - - slab_early_init = 0; - - /* 4) Replace the bootstrap head arrays */ - { - struct array_cache *ptr; - - ptr = kmalloc(sizeof(struct arraycache_init), GFP_NOWAIT); - - memcpy(ptr, cpu_cache_get(kmem_cache), - sizeof(struct arraycache_init)); - /* - * Do not assume that spinlocks can be initialized via memcpy: - */ - spin_lock_init(&ptr->lock); - - kmem_cache->array[smp_processor_id()] = ptr; - - ptr = kmalloc(sizeof(struct arraycache_init), GFP_NOWAIT); - - BUG_ON(cpu_cache_get(kmalloc_caches[INDEX_AC]) - != &initarray_generic.cache); - memcpy(ptr, cpu_cache_get(kmalloc_caches[INDEX_AC]), - sizeof(struct arraycache_init)); - /* - * Do not assume that spinlocks can be initialized via memcpy: - */ - spin_lock_init(&ptr->lock); - - kmalloc_caches[INDEX_AC]->array[smp_processor_id()] = ptr; - } - /* 5) Replace the bootstrap kmem_cache_node */ - { - int nid; - - for_each_online_node(nid) { - init_list(kmem_cache, &init_kmem_cache_node[CACHE_CACHE + nid], nid); - - init_list(kmalloc_caches[INDEX_AC], - &init_kmem_cache_node[SIZE_AC + nid], nid); - - if (INDEX_AC != INDEX_NODE) { - init_list(kmalloc_caches[INDEX_NODE], - &init_kmem_cache_node[SIZE_NODE + nid], nid); - } - } - } - - create_kmalloc_caches(ARCH_KMALLOC_FLAGS); -} - -void __init kmem_cache_init_late(void) -{ - struct kmem_cache *cachep; - - slab_state = UP; - - /* 6) resize the head arrays to their final sizes */ - mutex_lock(&slab_mutex); - list_for_each_entry(cachep, &slab_caches, list) - if (enable_cpucache(cachep, GFP_NOWAIT)) - BUG(); - mutex_unlock(&slab_mutex); - - /* Annotate slab for lockdep -- annotate the malloc caches */ - init_lock_keys(); - - /* Done! */ - slab_state = FULL; - - /* - * Register a cpu startup notifier callback that initializes - * cpu_cache_get for all new cpus - */ - register_cpu_notifier(&cpucache_notifier); - -#ifdef CONFIG_NUMA - /* - * Register a memory hotplug callback that initializes and frees - * node. - */ - hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI); -#endif - - /* - * The reap timers are started later, with a module init call: That part - * of the kernel is not yet operational. - */ -} - -static int __init cpucache_init(void) -{ - int cpu; - - /* - * Register the timers that return unneeded pages to the page allocator - */ - for_each_online_cpu(cpu) - start_cpu_timer(cpu); - - /* Done! */ - slab_state = FULL; - return 0; -} -__initcall(cpucache_init); - -static noinline void -slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid) -{ - struct kmem_cache_node *n; - struct slab *slabp; - unsigned long flags; - int node; - - printk(KERN_WARNING - "SLAB: Unable to allocate memory on node %d (gfp=0x%x)\n", - nodeid, gfpflags); - printk(KERN_WARNING " cache: %s, object size: %d, order: %d\n", - cachep->name, cachep->size, cachep->gfporder); - - for_each_online_node(node) { - unsigned long active_objs = 0, num_objs = 0, free_objects = 0; - unsigned long active_slabs = 0, num_slabs = 0; - - n = cachep->node[node]; - if (!n) - continue; - - spin_lock_irqsave(&n->list_lock, flags); - list_for_each_entry(slabp, &n->slabs_full, list) { - active_objs += cachep->num; - active_slabs++; - } - list_for_each_entry(slabp, &n->slabs_partial, list) { - active_objs += slabp->inuse; - active_slabs++; - } - list_for_each_entry(slabp, &n->slabs_free, list) - num_slabs++; - - free_objects += n->free_objects; - spin_unlock_irqrestore(&n->list_lock, flags); - - num_slabs += active_slabs; - num_objs = num_slabs * cachep->num; - printk(KERN_WARNING - " node %d: slabs: %ld/%ld, objs: %ld/%ld, free: %ld\n", - node, active_slabs, num_slabs, active_objs, num_objs, - free_objects); - } -} - -/* - * Interface to system's page allocator. No need to hold the cache-lock. - * - * If we requested dmaable memory, we will get it. Even if we - * did not request dmaable memory, we might get it, but that - * would be relatively rare and ignorable. - */ -static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid) -{ - struct page *page; - int nr_pages; - int i; - -#ifndef CONFIG_MMU - /* - * Nommu uses slab's for process anonymous memory allocations, and thus - * requires __GFP_COMP to properly refcount higher order allocations - */ - flags |= __GFP_COMP; -#endif - - flags |= cachep->allocflags; - if (cachep->flags & SLAB_RECLAIM_ACCOUNT) - flags |= __GFP_RECLAIMABLE; - - page = alloc_pages_exact_node(nodeid, flags | __GFP_NOTRACK, cachep->gfporder); - if (!page) { - if (!(flags & __GFP_NOWARN) && printk_ratelimit()) - slab_out_of_memory(cachep, flags, nodeid); - return NULL; - } - - /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */ - if (unlikely(page->pfmemalloc)) - pfmemalloc_active = true; - - nr_pages = (1 << cachep->gfporder); - if (cachep->flags & SLAB_RECLAIM_ACCOUNT) - 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); - - if (page->pfmemalloc) - SetPageSlabPfmemalloc(page + i); - } - memcg_bind_pages(cachep, cachep->gfporder); - - if (kmemcheck_enabled && !(cachep->flags & SLAB_NOTRACK)) { - kmemcheck_alloc_shadow(page, cachep->gfporder, flags, nodeid); - - if (cachep->ctor) - kmemcheck_mark_uninitialized_pages(page, nr_pages); - else - kmemcheck_mark_unallocated_pages(page, nr_pages); - } - - return page_address(page); -} - -/* - * Interface to system's page release. - */ -static void kmem_freepages(struct kmem_cache *cachep, void *addr) -{ - unsigned long i = (1 << cachep->gfporder); - struct page *page = virt_to_page(addr); - const unsigned long nr_freed = i; - - kmemcheck_free_shadow(page, cachep->gfporder); - - 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)); - __ClearPageSlabPfmemalloc(page); - __ClearPageSlab(page); - page++; - } - - memcg_release_pages(cachep, cachep->gfporder); - if (current->reclaim_state) - current->reclaim_state->reclaimed_slab += nr_freed; - free_memcg_kmem_pages((unsigned long)addr, cachep->gfporder); -} - -static void kmem_rcu_free(struct rcu_head *head) -{ - struct slab_rcu *slab_rcu = (struct slab_rcu *)head; - struct kmem_cache *cachep = slab_rcu->cachep; - - kmem_freepages(cachep, slab_rcu->addr); - if (OFF_SLAB(cachep)) - kmem_cache_free(cachep->slabp_cache, slab_rcu); -} - -#if DEBUG - -#ifdef CONFIG_DEBUG_PAGEALLOC -static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr, - unsigned long caller) -{ - int size = cachep->object_size; - - addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)]; - - if (size < 5 * sizeof(unsigned long)) - return; - - *addr++ = 0x12345678; - *addr++ = caller; - *addr++ = smp_processor_id(); - size -= 3 * sizeof(unsigned long); - { - unsigned long *sptr = &caller; - unsigned long svalue; - - while (!kstack_end(sptr)) { - svalue = *sptr++; - if (kernel_text_address(svalue)) { - *addr++ = svalue; - size -= sizeof(unsigned long); - if (size <= sizeof(unsigned long)) - break; - } - } - - } - *addr++ = 0x87654321; -} -#endif - -static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val) -{ - int size = cachep->object_size; - addr = &((char *)addr)[obj_offset(cachep)]; - - memset(addr, val, size); - *(unsigned char *)(addr + size - 1) = POISON_END; -} - -static void dump_line(char *data, int offset, int limit) -{ - int i; - 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) { - error = data[offset + i]; - bad_count++; - } - } - print_hex_dump(KERN_CONT, "", 0, 16, 1, - &data[offset], limit, 1); - - if (bad_count == 1) { - 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"); -#else - printk(KERN_ERR "Run a memory test tool.\n"); -#endif - } - } -} -#endif - -#if DEBUG - -static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines) -{ - int i, size; - char *realobj; - - if (cachep->flags & SLAB_RED_ZONE) { - printk(KERN_ERR "Redzone: 0x%llx/0x%llx.\n", - *dbg_redzone1(cachep, objp), - *dbg_redzone2(cachep, objp)); - } - - if (cachep->flags & SLAB_STORE_USER) { - printk(KERN_ERR "Last user: [<%p>](%pSR)\n", - *dbg_userword(cachep, objp), - *dbg_userword(cachep, objp)); - } - realobj = (char *)objp + obj_offset(cachep); - size = cachep->object_size; - for (i = 0; i < size && lines; i += 16, lines--) { - int limit; - limit = 16; - if (i + limit > size) - limit = size - i; - dump_line(realobj, i, limit); - } -} - -static void check_poison_obj(struct kmem_cache *cachep, void *objp) -{ - char *realobj; - int size, i; - int lines = 0; - - realobj = (char *)objp + obj_offset(cachep); - size = cachep->object_size; - - for (i = 0; i < size; i++) { - char exp = POISON_FREE; - if (i == size - 1) - exp = POISON_END; - if (realobj[i] != exp) { - int limit; - /* Mismatch ! */ - /* Print header */ - if (lines == 0) { - printk(KERN_ERR - "Slab corruption (%s): %s start=%p, len=%d\n", - print_tainted(), cachep->name, realobj, size); - print_objinfo(cachep, objp, 0); - } - /* Hexdump the affected line */ - i = (i / 16) * 16; - limit = 16; - if (i + limit > size) - limit = size - i; - dump_line(realobj, i, limit); - i += 16; - lines++; - /* Limit to 5 lines */ - if (lines > 5) - break; - } - } - if (lines != 0) { - /* Print some data about the neighboring objects, if they - * exist: - */ - struct slab *slabp = virt_to_slab(objp); - unsigned int objnr; - - objnr = obj_to_index(cachep, slabp, objp); - if (objnr) { - objp = index_to_obj(cachep, slabp, objnr - 1); - realobj = (char *)objp + obj_offset(cachep); - printk(KERN_ERR "Prev obj: start=%p, len=%d\n", - realobj, size); - print_objinfo(cachep, objp, 2); - } - if (objnr + 1 < cachep->num) { - objp = index_to_obj(cachep, slabp, objnr + 1); - realobj = (char *)objp + obj_offset(cachep); - printk(KERN_ERR "Next obj: start=%p, len=%d\n", - realobj, size); - print_objinfo(cachep, objp, 2); - } - } -} -#endif - -#if DEBUG -static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp) -{ - int i; - for (i = 0; i < cachep->num; i++) { - void *objp = index_to_obj(cachep, slabp, i); - - if (cachep->flags & SLAB_POISON) { -#ifdef CONFIG_DEBUG_PAGEALLOC - if (cachep->size % PAGE_SIZE == 0 && - OFF_SLAB(cachep)) - kernel_map_pages(virt_to_page(objp), - cachep->size / PAGE_SIZE, 1); - else - check_poison_obj(cachep, objp); -#else - check_poison_obj(cachep, objp); -#endif - } - if (cachep->flags & SLAB_RED_ZONE) { - if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) - slab_error(cachep, "start of a freed object " - "was overwritten"); - if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) - slab_error(cachep, "end of a freed object " - "was overwritten"); - } - } -} -#else -static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp) -{ -} -#endif - -/** - * slab_destroy - destroy and release all objects in a slab - * @cachep: cache pointer being destroyed - * @slabp: slab pointer being destroyed - * - * Destroy all the objs in a slab, and release the mem back to the system. - * Before calling the slab must have been unlinked from the cache. The - * cache-lock is not held/needed. - */ -static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp) -{ - void *addr = slabp->s_mem - slabp->colouroff; - - slab_destroy_debugcheck(cachep, slabp); - if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) { - struct slab_rcu *slab_rcu; - - slab_rcu = (struct slab_rcu *)slabp; - slab_rcu->cachep = cachep; - slab_rcu->addr = addr; - call_rcu(&slab_rcu->head, kmem_rcu_free); - } else { - kmem_freepages(cachep, addr); - if (OFF_SLAB(cachep)) - kmem_cache_free(cachep->slabp_cache, slabp); - } -} - -/** - * calculate_slab_order - calculate size (page order) of slabs - * @cachep: pointer to the cache that is being created - * @size: size of objects to be created in this cache. - * @align: required alignment for the objects. - * @flags: slab allocation flags - * - * Also calculates the number of objects per slab. - * - * This could be made much more intelligent. For now, try to avoid using - * high order pages for slabs. When the gfp() functions are more friendly - * towards high-order requests, this should be changed. - */ -static size_t calculate_slab_order(struct kmem_cache *cachep, - size_t size, size_t align, unsigned long flags) -{ - unsigned long offslab_limit; - size_t left_over = 0; - int gfporder; - - for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) { - unsigned int num; - size_t remainder; - - cache_estimate(gfporder, size, align, flags, &remainder, &num); - if (!num) - continue; - - if (flags & CFLGS_OFF_SLAB) { - /* - * Max number of objs-per-slab for caches which - * use off-slab slabs. Needed to avoid a possible - * looping condition in cache_grow(). - */ - offslab_limit = size - sizeof(struct slab); - offslab_limit /= sizeof(kmem_bufctl_t); - - if (num > offslab_limit) - break; - } - - /* Found something acceptable - save it away */ - cachep->num = num; - cachep->gfporder = gfporder; - left_over = remainder; - - /* - * A VFS-reclaimable slab tends to have most allocations - * as GFP_NOFS and we really don't want to have to be allocating - * higher-order pages when we are unable to shrink dcache. - */ - if (flags & SLAB_RECLAIM_ACCOUNT) - break; - - /* - * Large number of objects is good, but very large slabs are - * currently bad for the gfp()s. - */ - if (gfporder >= slab_max_order) - break; - - /* - * Acceptable internal fragmentation? - */ - if (left_over * 8 <= (PAGE_SIZE << gfporder)) - break; - } - return left_over; -} - -static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp) -{ - if (slab_state >= FULL) - return enable_cpucache(cachep, gfp); - - if (slab_state == DOWN) { - /* - * Note: Creation of first cache (kmem_cache). - * The setup_node is taken care - * of by the caller of __kmem_cache_create - */ - cachep->array[smp_processor_id()] = &initarray_generic.cache; - slab_state = PARTIAL; - } else if (slab_state == PARTIAL) { - /* - * Note: the second kmem_cache_create must create the cache - * that's used by kmalloc(24), otherwise the creation of - * further caches will BUG(). - */ - cachep->array[smp_processor_id()] = &initarray_generic.cache; - - /* - * If the cache that's used by kmalloc(sizeof(kmem_cache_node)) is - * the second cache, then we need to set up all its node/, - * otherwise the creation of further caches will BUG(). - */ - set_up_node(cachep, SIZE_AC); - if (INDEX_AC == INDEX_NODE) - slab_state = PARTIAL_NODE; - else - slab_state = PARTIAL_ARRAYCACHE; - } else { - /* Remaining boot caches */ - cachep->array[smp_processor_id()] = - kmalloc(sizeof(struct arraycache_init), gfp); - - if (slab_state == PARTIAL_ARRAYCACHE) { - set_up_node(cachep, SIZE_NODE); - slab_state = PARTIAL_NODE; - } else { - int node; - for_each_online_node(node) { - cachep->node[node] = - kmalloc_node(sizeof(struct kmem_cache_node), - gfp, node); - BUG_ON(!cachep->node[node]); - kmem_cache_node_init(cachep->node[node]); - } - } - } - cachep->node[numa_mem_id()]->next_reap = - jiffies + REAPTIMEOUT_LIST3 + - ((unsigned long)cachep) % REAPTIMEOUT_LIST3; - - cpu_cache_get(cachep)->avail = 0; - cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES; - cpu_cache_get(cachep)->batchcount = 1; - cpu_cache_get(cachep)->touched = 0; - cachep->batchcount = 1; - cachep->limit = BOOT_CPUCACHE_ENTRIES; - return 0; -} - -/** - * __kmem_cache_create - Create a cache. - * @cachep: cache management descriptor - * @flags: SLAB flags - * - * Returns a ptr to the cache on success, NULL on failure. - * Cannot be called within a int, but can be interrupted. - * The @ctor is run when new pages are allocated by the cache. - * - * The flags are - * - * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) - * to catch references to uninitialised memory. - * - * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check - * for buffer overruns. - * - * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware - * cacheline. This can be beneficial if you're counting cycles as closely - * as davem. - */ -int -__kmem_cache_create (struct kmem_cache *cachep, unsigned long flags) -{ - size_t left_over, slab_size, ralign; - gfp_t gfp; - int err; - size_t size = cachep->size; - -#if DEBUG -#if FORCED_DEBUG - /* - * Enable redzoning and last user accounting, except for caches with - * large objects, if the increased size would increase the object size - * above the next power of two: caches with object sizes just above a - * power of two have a significant amount of internal fragmentation. - */ - if (size < 4096 || fls(size - 1) == fls(size-1 + REDZONE_ALIGN + - 2 * sizeof(unsigned long long))) - flags |= SLAB_RED_ZONE | SLAB_STORE_USER; - if (!(flags & SLAB_DESTROY_BY_RCU)) - flags |= SLAB_POISON; -#endif - if (flags & SLAB_DESTROY_BY_RCU) - BUG_ON(flags & SLAB_POISON); -#endif - - /* - * Check that size is in terms of words. This is needed to avoid - * unaligned accesses for some archs when redzoning is used, and makes - * sure any on-slab bufctl's are also correctly aligned. - */ - if (size & (BYTES_PER_WORD - 1)) { - size += (BYTES_PER_WORD - 1); - size &= ~(BYTES_PER_WORD - 1); - } - - /* - * Redzoning and user store require word alignment or possibly larger. - * Note this will be overridden by architecture or caller mandated - * alignment if either is greater than BYTES_PER_WORD. - */ - if (flags & SLAB_STORE_USER) - ralign = BYTES_PER_WORD; - - if (flags & SLAB_RED_ZONE) { - ralign = REDZONE_ALIGN; - /* If redzoning, ensure that the second redzone is suitably - * aligned, by adjusting the object size accordingly. */ - size += REDZONE_ALIGN - 1; - size &= ~(REDZONE_ALIGN - 1); - } - - /* 3) caller mandated alignment */ - if (ralign < cachep->align) { - ralign = cachep->align; - } - /* disable debug if necessary */ - if (ralign > __alignof__(unsigned long long)) - flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); - /* - * 4) Store it. - */ - cachep->align = ralign; - - if (slab_is_available()) - gfp = GFP_KERNEL; - else - gfp = GFP_NOWAIT; - - setup_node_pointer(cachep); -#if DEBUG - - /* - * Both debugging options require word-alignment which is calculated - * into align above. - */ - if (flags & SLAB_RED_ZONE) { - /* add space for red zone words */ - cachep->obj_offset += sizeof(unsigned long long); - size += 2 * sizeof(unsigned long long); - } - if (flags & SLAB_STORE_USER) { - /* user store requires one word storage behind the end of - * the real object. But if the second red zone needs to be - * aligned to 64 bits, we must allow that much space. - */ - if (flags & SLAB_RED_ZONE) - size += REDZONE_ALIGN; - else - size += BYTES_PER_WORD; - } -#if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC) - if (size >= kmalloc_size(INDEX_NODE + 1) - && cachep->object_size > cache_line_size() - && ALIGN(size, cachep->align) < PAGE_SIZE) { - cachep->obj_offset += PAGE_SIZE - ALIGN(size, cachep->align); - size = PAGE_SIZE; - } -#endif -#endif - - /* - * Determine if the slab management is 'on' or 'off' slab. - * (bootstrapping cannot cope with offslab caches so don't do - * it too early on. Always use on-slab management when - * SLAB_NOLEAKTRACE to avoid recursive calls into kmemleak) - */ - if ((size >= (PAGE_SIZE >> 3)) && !slab_early_init && - !(flags & SLAB_NOLEAKTRACE)) - /* - * Size is large, assume best to place the slab management obj - * off-slab (should allow better packing of objs). - */ - flags |= CFLGS_OFF_SLAB; - - size = ALIGN(size, cachep->align); - - left_over = calculate_slab_order(cachep, size, cachep->align, flags); - - if (!cachep->num) - return -E2BIG; - - slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t) - + sizeof(struct slab), cachep->align); - - /* - * If the slab has been placed off-slab, and we have enough space then - * move it on-slab. This is at the expense of any extra colouring. - */ - if (flags & CFLGS_OFF_SLAB && left_over >= slab_size) { - flags &= ~CFLGS_OFF_SLAB; - left_over -= slab_size; - } - - if (flags & CFLGS_OFF_SLAB) { - /* really off slab. No need for manual alignment */ - slab_size = - cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab); - -#ifdef CONFIG_PAGE_POISONING - /* If we're going to use the generic kernel_map_pages() - * poisoning, then it's going to smash the contents of - * the redzone and userword anyhow, so switch them off. - */ - if (size % PAGE_SIZE == 0 && flags & SLAB_POISON) - flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); -#endif - } - - cachep->colour_off = cache_line_size(); - /* Offset must be a multiple of the alignment. */ - if (cachep->colour_off < cachep->align) - cachep->colour_off = cachep->align; - cachep->colour = left_over / cachep->colour_off; - cachep->slab_size = slab_size; - cachep->flags = flags; - cachep->allocflags = 0; - if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA)) - cachep->allocflags |= GFP_DMA; - cachep->size = size; - cachep->reciprocal_buffer_size = reciprocal_value(size); - - if (flags & CFLGS_OFF_SLAB) { - cachep->slabp_cache = kmalloc_slab(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(ZERO_OR_NULL_PTR(cachep->slabp_cache)); - } - - err = setup_cpu_cache(cachep, gfp); - if (err) { - __kmem_cache_shutdown(cachep); - return err; - } - - if (flags & SLAB_DEBUG_OBJECTS) { - /* - * Would deadlock through slab_destroy()->call_rcu()-> - * debug_object_activate()->kmem_cache_alloc(). - */ - WARN_ON_ONCE(flags & SLAB_DESTROY_BY_RCU); - - slab_set_debugobj_lock_classes(cachep); - } else if (!OFF_SLAB(cachep) && !(flags & SLAB_DESTROY_BY_RCU)) - on_slab_lock_classes(cachep); - - return 0; -} - -#if DEBUG -static void check_irq_off(void) -{ - BUG_ON(!irqs_disabled()); -} - -static void check_irq_on(void) -{ - BUG_ON(irqs_disabled()); -} - -static void check_spinlock_acquired(struct kmem_cache *cachep) -{ -#ifdef CONFIG_SMP - check_irq_off(); - assert_spin_locked(&cachep->node[numa_mem_id()]->list_lock); -#endif -} - -static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node) -{ -#ifdef CONFIG_SMP - check_irq_off(); - assert_spin_locked(&cachep->node[node]->list_lock); -#endif -} - -#else -#define check_irq_off() do { } while(0) -#define check_irq_on() do { } while(0) -#define check_spinlock_acquired(x) do { } while(0) -#define check_spinlock_acquired_node(x, y) do { } while(0) -#endif - -static void drain_array(struct kmem_cache *cachep, struct kmem_cache_node *n, - struct array_cache *ac, - int force, int node); - -static void do_drain(void *arg) -{ - struct kmem_cache *cachep = arg; - struct array_cache *ac; - int node = numa_mem_id(); - - check_irq_off(); - ac = cpu_cache_get(cachep); - spin_lock(&cachep->node[node]->list_lock); - free_block(cachep, ac->entry, ac->avail, node); - spin_unlock(&cachep->node[node]->list_lock); - ac->avail = 0; -} - -static void drain_cpu_caches(struct kmem_cache *cachep) -{ - struct kmem_cache_node *n; - int node; - - on_each_cpu(do_drain, cachep, 1); - check_irq_on(); - for_each_online_node(node) { - n = cachep->node[node]; - if (n && n->alien) - drain_alien_cache(cachep, n->alien); - } - - for_each_online_node(node) { - n = cachep->node[node]; - if (n) - drain_array(cachep, n, n->shared, 1, node); - } -} - -/* - * Remove slabs from the list of free slabs. - * Specify the number of slabs to drain in tofree. - * - * Returns the actual number of slabs released. - */ -static int drain_freelist(struct kmem_cache *cache, - struct kmem_cache_node *n, int tofree) -{ - struct list_head *p; - int nr_freed; - struct slab *slabp; - - nr_freed = 0; - while (nr_freed < tofree && !list_empty(&n->slabs_free)) { - - spin_lock_irq(&n->list_lock); - p = n->slabs_free.prev; - if (p == &n->slabs_free) { - spin_unlock_irq(&n->list_lock); - goto out; - } - - slabp = list_entry(p, struct slab, list); -#if DEBUG - BUG_ON(slabp->inuse); -#endif - list_del(&slabp->list); - /* - * Safe to drop the lock. The slab is no longer linked - * to the cache. - */ - n->free_objects -= cache->num; - spin_unlock_irq(&n->list_lock); - slab_destroy(cache, slabp); - nr_freed++; - } -out: - return nr_freed; -} - -/* Called with slab_mutex held to protect against cpu hotplug */ -static int __cache_shrink(struct kmem_cache *cachep) -{ - int ret = 0, i = 0; - struct kmem_cache_node *n; - - drain_cpu_caches(cachep); - - check_irq_on(); - for_each_online_node(i) { - n = cachep->node[i]; - if (!n) - continue; - - drain_freelist(cachep, n, slabs_tofree(cachep, n)); - - ret += !list_empty(&n->slabs_full) || - !list_empty(&n->slabs_partial); - } - return (ret ? 1 : 0); -} - -/** - * kmem_cache_shrink - Shrink a cache. - * @cachep: The cache to shrink. - * - * Releases as many slabs as possible for a cache. - * To help debugging, a zero exit status indicates all slabs were released. - */ -int kmem_cache_shrink(struct kmem_cache *cachep) -{ - int ret; - BUG_ON(!cachep || in_interrupt()); - - get_online_cpus(); - mutex_lock(&slab_mutex); - ret = __cache_shrink(cachep); - mutex_unlock(&slab_mutex); - put_online_cpus(); - return ret; -} -EXPORT_SYMBOL(kmem_cache_shrink); - -int __kmem_cache_shutdown(struct kmem_cache *cachep) -{ - int i; - struct kmem_cache_node *n; - int rc = __cache_shrink(cachep); - - if (rc) - return rc; - - for_each_online_cpu(i) - kfree(cachep->array[i]); - - /* NUMA: free the node structures */ - for_each_online_node(i) { - n = cachep->node[i]; - if (n) { - kfree(n->shared); - free_alien_cache(n->alien); - kfree(n); - } - } - return 0; -} - -/* - * 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) -{ - struct slab *slabp; - - if (OFF_SLAB(cachep)) { - /* Slab management obj is off-slab. */ - slabp = kmem_cache_alloc_node(cachep->slabp_cache, - local_flags, nodeid); - /* - * If the first object in the slab is leaked (it's allocated - * but no one has a reference to it), we want to make sure - * kmemleak does not treat the ->s_mem pointer as a reference - * to the object. Otherwise we will not report the leak. - */ - kmemleak_scan_area(&slabp->list, sizeof(struct list_head), - local_flags); - if (!slabp) - return NULL; - } else { - slabp = objp + colour_off; - colour_off += cachep->slab_size; - } - slabp->inuse = 0; - slabp->colouroff = colour_off; - slabp->s_mem = objp + colour_off; - slabp->nodeid = nodeid; - slabp->free = 0; - return slabp; -} - -static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp) -{ - return (kmem_bufctl_t *) (slabp + 1); -} - -static void cache_init_objs(struct kmem_cache *cachep, - struct slab *slabp) -{ - int i; - - for (i = 0; i < cachep->num; i++) { - void *objp = index_to_obj(cachep, slabp, i); -#if DEBUG - /* need to poison the objs? */ - if (cachep->flags & SLAB_POISON) - poison_obj(cachep, objp, POISON_FREE); - if (cachep->flags & SLAB_STORE_USER) - *dbg_userword(cachep, objp) = NULL; - - if (cachep->flags & SLAB_RED_ZONE) { - *dbg_redzone1(cachep, objp) = RED_INACTIVE; - *dbg_redzone2(cachep, objp) = RED_INACTIVE; - } - /* - * Constructors are not allowed to allocate memory from the same - * cache which they are a constructor for. Otherwise, deadlock. - * They must also be threaded. - */ - if (cachep->ctor && !(cachep->flags & SLAB_POISON)) - cachep->ctor(objp + obj_offset(cachep)); - - if (cachep->flags & SLAB_RED_ZONE) { - if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) - slab_error(cachep, "constructor overwrote the" - " end of an object"); - if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) - slab_error(cachep, "constructor overwrote the" - " start of an object"); - } - if ((cachep->size % PAGE_SIZE) == 0 && - OFF_SLAB(cachep) && cachep->flags & SLAB_POISON) - kernel_map_pages(virt_to_page(objp), - cachep->size / PAGE_SIZE, 0); -#else - if (cachep->ctor) - cachep->ctor(objp); -#endif - slab_bufctl(slabp)[i] = i + 1; - } - slab_bufctl(slabp)[i - 1] = BUFCTL_END; -} - -static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags) -{ - if (CONFIG_ZONE_DMA_FLAG) { - if (flags & GFP_DMA) - BUG_ON(!(cachep->allocflags & GFP_DMA)); - else - BUG_ON(cachep->allocflags & GFP_DMA); - } -} - -static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp, - int nodeid) -{ - void *objp = index_to_obj(cachep, slabp, slabp->free); - kmem_bufctl_t next; - - slabp->inuse++; - next = slab_bufctl(slabp)[slabp->free]; -#if DEBUG - slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE; - WARN_ON(slabp->nodeid != nodeid); -#endif - slabp->free = next; - - return objp; -} - -static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp, - void *objp, int nodeid) -{ - unsigned int objnr = obj_to_index(cachep, slabp, objp); - -#if DEBUG - /* Verify that the slab belongs to the intended node */ - WARN_ON(slabp->nodeid != nodeid); - - if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) { - printk(KERN_ERR "slab: double free detected in cache " - "'%s', objp %p\n", cachep->name, objp); - BUG(); - } -#endif - slab_bufctl(slabp)[objnr] = slabp->free; - slabp->free = objnr; - slabp->inuse--; -} - -/* - * Map pages beginning at addr to the given cache and slab. This is required - * for the slab allocator to be able to lookup the cache and slab of a - * virtual address for kfree, ksize, and slab debugging. - */ -static void slab_map_pages(struct kmem_cache *cache, struct slab *slab, - void *addr) -{ - int nr_pages; - struct page *page; - - page = virt_to_page(addr); - - nr_pages = 1; - if (likely(!PageCompound(page))) - nr_pages <<= cache->gfporder; - - do { - page->slab_cache = cache; - page->slab_page = slab; - page++; - } while (--nr_pages); -} - -/* - * 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, void *objp) -{ - struct slab *slabp; - size_t offset; - gfp_t local_flags; - struct kmem_cache_node *n; - - /* - * Be lazy and only check for valid flags here, keeping it out of the - * critical path in kmem_cache_alloc(). - */ - BUG_ON(flags & GFP_SLAB_BUG_MASK); - local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); - - /* Take the node list lock to change the colour_next on this node */ - check_irq_off(); - n = cachep->node[nodeid]; - spin_lock(&n->list_lock); - - /* Get colour for the slab, and cal the next value. */ - offset = n->colour_next; - n->colour_next++; - if (n->colour_next >= cachep->colour) - n->colour_next = 0; - spin_unlock(&n->list_lock); - - offset *= cachep->colour_off; - - if (local_flags & __GFP_WAIT) - local_irq_enable(); - - /* - * The test for missing atomic flag is performed here, rather than - * the more obvious place, simply to reduce the critical path length - * in kmem_cache_alloc(). If a caller is seriously mis-behaving they - * will eventually be caught here (where it matters). - */ - kmem_flagcheck(cachep, flags); - - /* - * Get mem for the objs. Attempt to allocate a physical page from - * 'nodeid'. - */ - if (!objp) - objp = kmem_getpages(cachep, local_flags, nodeid); - if (!objp) - goto failed; - - /* Get slab management. */ - slabp = alloc_slabmgmt(cachep, objp, offset, - local_flags & ~GFP_CONSTRAINT_MASK, nodeid); - if (!slabp) - goto opps1; - - slab_map_pages(cachep, slabp, objp); - - cache_init_objs(cachep, slabp); - - if (local_flags & __GFP_WAIT) - local_irq_disable(); - check_irq_off(); - spin_lock(&n->list_lock); - - /* Make slab active. */ - list_add_tail(&slabp->list, &(n->slabs_free)); - STATS_INC_GROWN(cachep); - n->free_objects += cachep->num; - spin_unlock(&n->list_lock); - return 1; -opps1: - kmem_freepages(cachep, objp); -failed: - if (local_flags & __GFP_WAIT) - local_irq_disable(); - return 0; -} - -#if DEBUG - -/* - * Perform extra freeing checks: - * - detect bad pointers. - * - POISON/RED_ZONE checking - */ -static void kfree_debugcheck(const void *objp) -{ - if (!virt_addr_valid(objp)) { - printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n", - (unsigned long)objp); - BUG(); - } -} - -static inline void verify_redzone_free(struct kmem_cache *cache, void *obj) -{ - unsigned long long redzone1, redzone2; - - redzone1 = *dbg_redzone1(cache, obj); - redzone2 = *dbg_redzone2(cache, obj); - - /* - * Redzone is ok. - */ - if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE) - return; - - if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE) - slab_error(cache, "double free detected"); - else - slab_error(cache, "memory outside object was overwritten"); - - printk(KERN_ERR "%p: redzone 1:0x%llx, redzone 2:0x%llx.\n", - obj, redzone1, redzone2); -} - -static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp, - unsigned long caller) -{ - struct page *page; - unsigned int objnr; - struct slab *slabp; - - BUG_ON(virt_to_cache(objp) != cachep); - - objp -= obj_offset(cachep); - kfree_debugcheck(objp); - page = virt_to_head_page(objp); - - slabp = page->slab_page; - - if (cachep->flags & SLAB_RED_ZONE) { - verify_redzone_free(cachep, objp); - *dbg_redzone1(cachep, objp) = RED_INACTIVE; - *dbg_redzone2(cachep, objp) = RED_INACTIVE; - } - if (cachep->flags & SLAB_STORE_USER) - *dbg_userword(cachep, objp) = (void *)caller; - - objnr = obj_to_index(cachep, slabp, objp); - - BUG_ON(objnr >= cachep->num); - BUG_ON(objp != index_to_obj(cachep, slabp, objnr)); - -#ifdef CONFIG_DEBUG_SLAB_LEAK - slab_bufctl(slabp)[objnr] = BUFCTL_FREE; -#endif - if (cachep->flags & SLAB_POISON) { -#ifdef CONFIG_DEBUG_PAGEALLOC - if ((cachep->size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) { - store_stackinfo(cachep, objp, caller); - kernel_map_pages(virt_to_page(objp), - cachep->size / PAGE_SIZE, 0); - } else { - poison_obj(cachep, objp, POISON_FREE); - } -#else - poison_obj(cachep, objp, POISON_FREE); -#endif - } - return objp; -} - -static void check_slabp(struct kmem_cache *cachep, struct slab *slabp) -{ - kmem_bufctl_t i; - int entries = 0; - - /* Check slab's freelist to see if this obj is there. */ - for (i = slabp->free; i != BUFCTL_END; i = slab_bufctl(slabp)[i]) { - entries++; - if (entries > cachep->num || i >= cachep->num) - goto bad; - } - if (entries != cachep->num - slabp->inuse) { -bad: - printk(KERN_ERR "slab: Internal list corruption detected in " - "cache '%s'(%d), slabp %p(%d). Tainted(%s). Hexdump:\n", - cachep->name, cachep->num, slabp, slabp->inuse, - print_tainted()); - print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1, slabp, - sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t), - 1); - BUG(); - } -} -#else -#define kfree_debugcheck(x) do { } while(0) -#define cache_free_debugcheck(x,objp,z) (objp) -#define check_slabp(x,y) do { } while(0) -#endif - -static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags, - bool force_refill) -{ - int batchcount; - struct kmem_cache_node *n; - struct array_cache *ac; - int node; - - check_irq_off(); - node = numa_mem_id(); - if (unlikely(force_refill)) - goto force_grow; -retry: - ac = cpu_cache_get(cachep); - batchcount = ac->batchcount; - if (!ac->touched && batchcount > BATCHREFILL_LIMIT) { - /* - * If there was little recent activity on this cache, then - * perform only a partial refill. Otherwise we could generate - * refill bouncing. - */ - batchcount = BATCHREFILL_LIMIT; - } - n = cachep->node[node]; - - BUG_ON(ac->avail > 0 || !n); - spin_lock(&n->list_lock); - - /* See if we can refill from the shared array */ - if (n->shared && transfer_objects(ac, n->shared, batchcount)) { - n->shared->touched = 1; - goto alloc_done; - } - - while (batchcount > 0) { - struct list_head *entry; - struct slab *slabp; - /* Get slab alloc is to come from. */ - entry = n->slabs_partial.next; - if (entry == &n->slabs_partial) { - n->free_touched = 1; - entry = n->slabs_free.next; - if (entry == &n->slabs_free) - goto must_grow; - } - - slabp = list_entry(entry, struct slab, list); - check_slabp(cachep, slabp); - check_spinlock_acquired(cachep); - - /* - * The slab was either on partial or free list so - * there must be at least one object available for - * allocation. - */ - BUG_ON(slabp->inuse >= cachep->num); - - while (slabp->inuse < cachep->num && batchcount--) { - STATS_INC_ALLOCED(cachep); - STATS_INC_ACTIVE(cachep); - STATS_SET_HIGH(cachep); - - ac_put_obj(cachep, ac, slab_get_obj(cachep, slabp, - node)); - } - check_slabp(cachep, slabp); - - /* move slabp to correct slabp list: */ - list_del(&slabp->list); - if (slabp->free == BUFCTL_END) - list_add(&slabp->list, &n->slabs_full); - else - list_add(&slabp->list, &n->slabs_partial); - } - -must_grow: - n->free_objects -= ac->avail; -alloc_done: - spin_unlock(&n->list_lock); - - if (unlikely(!ac->avail)) { - int x; -force_grow: - x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL); - - /* cache_grow can reenable interrupts, then ac could change. */ - ac = cpu_cache_get(cachep); - node = numa_mem_id(); - - /* no objects in sight? abort */ - if (!x && (ac->avail == 0 || force_refill)) - return NULL; - - if (!ac->avail) /* objects refilled by interrupt? */ - goto retry; - } - ac->touched = 1; - - return ac_get_obj(cachep, ac, flags, force_refill); -} - -static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep, - gfp_t flags) -{ - might_sleep_if(flags & __GFP_WAIT); -#if DEBUG - kmem_flagcheck(cachep, flags); -#endif -} - -#if DEBUG -static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep, - gfp_t flags, void *objp, unsigned long caller) -{ - if (!objp) - return objp; - if (cachep->flags & SLAB_POISON) { -#ifdef CONFIG_DEBUG_PAGEALLOC - if ((cachep->size % PAGE_SIZE) == 0 && OFF_SLAB(cachep)) - kernel_map_pages(virt_to_page(objp), - cachep->size / PAGE_SIZE, 1); - else - check_poison_obj(cachep, objp); -#else - check_poison_obj(cachep, objp); -#endif - poison_obj(cachep, objp, POISON_INUSE); - } - if (cachep->flags & SLAB_STORE_USER) - *dbg_userword(cachep, objp) = (void *)caller; - - if (cachep->flags & SLAB_RED_ZONE) { - if (*dbg_redzone1(cachep, objp) != RED_INACTIVE || - *dbg_redzone2(cachep, objp) != RED_INACTIVE) { - slab_error(cachep, "double free, or memory outside" - " object was overwritten"); - printk(KERN_ERR - "%p: redzone 1:0x%llx, redzone 2:0x%llx\n", - objp, *dbg_redzone1(cachep, objp), - *dbg_redzone2(cachep, objp)); - } - *dbg_redzone1(cachep, objp) = RED_ACTIVE; - *dbg_redzone2(cachep, objp) = RED_ACTIVE; - } -#ifdef CONFIG_DEBUG_SLAB_LEAK - { - struct slab *slabp; - unsigned objnr; - - slabp = virt_to_head_page(objp)->slab_page; - objnr = (unsigned)(objp - slabp->s_mem) / cachep->size; - slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE; - } -#endif - objp += obj_offset(cachep); - if (cachep->ctor && cachep->flags & SLAB_POISON) - cachep->ctor(objp); - if (ARCH_SLAB_MINALIGN && - ((unsigned long)objp & (ARCH_SLAB_MINALIGN-1))) { - printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n", - objp, (int)ARCH_SLAB_MINALIGN); - } - return objp; -} -#else -#define cache_alloc_debugcheck_after(a,b,objp,d) (objp) -#endif - -static bool slab_should_failslab(struct kmem_cache *cachep, gfp_t flags) -{ - if (cachep == kmem_cache) - return false; - - return should_failslab(cachep->object_size, flags, cachep->flags); -} - -static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) -{ - void *objp; - struct array_cache *ac; - bool force_refill = false; - - check_irq_off(); - - ac = cpu_cache_get(cachep); - if (likely(ac->avail)) { - ac->touched = 1; - objp = ac_get_obj(cachep, ac, flags, false); - - /* - * Allow for the possibility all avail objects are not allowed - * by the current flags - */ - if (objp) { - STATS_INC_ALLOCHIT(cachep); - goto out; - } - force_refill = true; - } - - STATS_INC_ALLOCMISS(cachep); - objp = cache_alloc_refill(cachep, flags, force_refill); - /* - * the 'ac' may be updated by cache_alloc_refill(), - * and kmemleak_erase() requires its correct value. - */ - ac = cpu_cache_get(cachep); - -out: - /* - * To avoid a false negative, if an object that is in one of the - * per-CPU caches is leaked, we need to make sure kmemleak doesn't - * treat the array pointers as a reference to the object. - */ - if (objp) - kmemleak_erase(&ac->entry[ac->avail]); - return objp; -} - -#ifdef CONFIG_NUMA -/* - * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY. - * - * If we are in_interrupt, then process context, including cpusets and - * mempolicy, may not apply and should not be used for allocation policy. - */ -static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags) -{ - int nid_alloc, nid_here; - - if (in_interrupt() || (flags & __GFP_THISNODE)) - return NULL; - nid_alloc = nid_here = numa_mem_id(); - if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD)) - nid_alloc = cpuset_slab_spread_node(); - else if (current->mempolicy) - nid_alloc = slab_node(); - if (nid_alloc != nid_here) - 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 node 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. - */ -static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags) -{ - struct zonelist *zonelist; - gfp_t local_flags; - struct zoneref *z; - struct zone *zone; - enum zone_type high_zoneidx = gfp_zone(flags); - void *obj = NULL; - int nid; - unsigned int cpuset_mems_cookie; - - if (flags & __GFP_THISNODE) - return NULL; - - local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); - -retry_cpuset: - cpuset_mems_cookie = get_mems_allowed(); - zonelist = node_zonelist(slab_node(), flags); - -retry: - /* - * Look through allowed nodes for objects available - * from existing per node queues. - */ - for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { - nid = zone_to_nid(zone); - - if (cpuset_zone_allowed_hardwall(zone, flags) && - cache->node[nid] && - cache->node[nid]->free_objects) { - obj = ____cache_alloc_node(cache, - flags | GFP_THISNODE, nid); - if (obj) - break; - } - } - - if (!obj) { - /* - * 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, local_flags, numa_mem_id()); - 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; - } - } - } - - if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !obj)) - goto retry_cpuset; - return obj; -} - -/* - * A interface to enable slab creation on nodeid - */ -static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, - int nodeid) -{ - struct list_head *entry; - struct slab *slabp; - struct kmem_cache_node *n; - void *obj; - int x; - - VM_BUG_ON(nodeid > num_online_nodes()); - n = cachep->node[nodeid]; - BUG_ON(!n); - -retry: - check_irq_off(); - spin_lock(&n->list_lock); - entry = n->slabs_partial.next; - if (entry == &n->slabs_partial) { - n->free_touched = 1; - entry = n->slabs_free.next; - if (entry == &n->slabs_free) - goto must_grow; - } - - slabp = list_entry(entry, struct slab, list); - check_spinlock_acquired_node(cachep, nodeid); - check_slabp(cachep, slabp); - - STATS_INC_NODEALLOCS(cachep); - STATS_INC_ACTIVE(cachep); - STATS_SET_HIGH(cachep); - - BUG_ON(slabp->inuse == cachep->num); - - obj = slab_get_obj(cachep, slabp, nodeid); - check_slabp(cachep, slabp); - n->free_objects--; - /* move slabp to correct slabp list: */ - list_del(&slabp->list); - - if (slabp->free == BUFCTL_END) - list_add(&slabp->list, &n->slabs_full); - else - list_add(&slabp->list, &n->slabs_partial); - - spin_unlock(&n->list_lock); - goto done; - -must_grow: - spin_unlock(&n->list_lock); - x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL); - if (x) - goto retry; - - return fallback_alloc(cachep, flags); - -done: - return obj; -} - -static __always_inline void * -slab_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid, - unsigned long caller) -{ - unsigned long save_flags; - void *ptr; - int slab_node = numa_mem_id(); - - flags &= gfp_allowed_mask; - - lockdep_trace_alloc(flags); - - if (slab_should_failslab(cachep, flags)) - return NULL; - - cachep = memcg_kmem_get_cache(cachep, flags); - - cache_alloc_debugcheck_before(cachep, flags); - local_irq_save(save_flags); - - if (nodeid == NUMA_NO_NODE) - nodeid = slab_node; - - if (unlikely(!cachep->node[nodeid])) { - /* Node not bootstrapped yet */ - ptr = fallback_alloc(cachep, flags); - goto out; - } - - if (nodeid == slab_node) { - /* - * 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) - goto out; - } - /* ___cache_alloc_node can fall back to other nodes */ - ptr = ____cache_alloc_node(cachep, flags, nodeid); - out: - local_irq_restore(save_flags); - ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller); - kmemleak_alloc_recursive(ptr, cachep->object_size, 1, cachep->flags, - flags); - - if (likely(ptr)) - kmemcheck_slab_alloc(cachep, flags, ptr, cachep->object_size); - - if (unlikely((flags & __GFP_ZERO) && ptr)) - memset(ptr, 0, cachep->object_size); - - return ptr; -} - -static __always_inline void * -__do_cache_alloc(struct kmem_cache *cache, gfp_t flags) -{ - void *objp; - - if (unlikely(current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) { - objp = alternate_node_alloc(cache, flags); - if (objp) - goto out; - } - objp = ____cache_alloc(cache, 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 (!objp) - objp = ____cache_alloc_node(cache, flags, numa_mem_id()); - - out: - return objp; -} -#else - -static __always_inline void * -__do_cache_alloc(struct kmem_cache *cachep, gfp_t flags) -{ - return ____cache_alloc(cachep, flags); -} - -#endif /* CONFIG_NUMA */ - -static __always_inline void * -slab_alloc(struct kmem_cache *cachep, gfp_t flags, unsigned long caller) -{ - unsigned long save_flags; - void *objp; - - flags &= gfp_allowed_mask; - - lockdep_trace_alloc(flags); - - if (slab_should_failslab(cachep, flags)) - return NULL; - - cachep = memcg_kmem_get_cache(cachep, flags); - - cache_alloc_debugcheck_before(cachep, flags); - local_irq_save(save_flags); - objp = __do_cache_alloc(cachep, flags); - local_irq_restore(save_flags); - objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller); - kmemleak_alloc_recursive(objp, cachep->object_size, 1, cachep->flags, - flags); - prefetchw(objp); - - if (likely(objp)) - kmemcheck_slab_alloc(cachep, flags, objp, cachep->object_size); - - if (unlikely((flags & __GFP_ZERO) && objp)) - memset(objp, 0, cachep->object_size); - - return objp; -} - -/* - * Caller needs to acquire correct kmem_list's list_lock - */ -static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects, - int node) -{ - int i; - struct kmem_cache_node *n; - - for (i = 0; i < nr_objects; i++) { - void *objp; - struct slab *slabp; - - clear_obj_pfmemalloc(&objpp[i]); - objp = objpp[i]; - - slabp = virt_to_slab(objp); - n = cachep->node[node]; - list_del(&slabp->list); - check_spinlock_acquired_node(cachep, node); - check_slabp(cachep, slabp); - slab_put_obj(cachep, slabp, objp, node); - STATS_DEC_ACTIVE(cachep); - n->free_objects++; - check_slabp(cachep, slabp); - - /* fixup slab chains */ - if (slabp->inuse == 0) { - if (n->free_objects > n->free_limit) { - n->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, &n->slabs_free); - } - } else { - /* Unconditionally move a slab to the end of the - * partial list on free - maximum time for the - * other objects to be freed, too. - */ - list_add_tail(&slabp->list, &n->slabs_partial); - } - } -} - -static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac) -{ - int batchcount; - struct kmem_cache_node *n; - int node = numa_mem_id(); - - batchcount = ac->batchcount; -#if DEBUG - BUG_ON(!batchcount || batchcount > ac->avail); -#endif - check_irq_off(); - n = cachep->node[node]; - spin_lock(&n->list_lock); - if (n->shared) { - struct array_cache *shared_array = n->shared; - int max = shared_array->limit - shared_array->avail; - if (max) { - if (batchcount > max) - batchcount = max; - memcpy(&(shared_array->entry[shared_array->avail]), - ac->entry, sizeof(void *) * batchcount); - shared_array->avail += batchcount; - goto free_done; - } - } - - free_block(cachep, ac->entry, batchcount, node); -free_done: -#if STATS - { - int i = 0; - struct list_head *p; - - p = n->slabs_free.next; - while (p != &(n->slabs_free)) { - struct slab *slabp; - - slabp = list_entry(p, struct slab, list); - BUG_ON(slabp->inuse); - - i++; - p = p->next; - } - STATS_SET_FREEABLE(cachep, i); - } -#endif - spin_unlock(&n->list_lock); - ac->avail -= batchcount; - memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail); -} - -/* - * Release an obj back to its cache. If the obj has a constructed state, it must - * be in this state _before_ it is released. Called with disabled ints. - */ -static inline void __cache_free(struct kmem_cache *cachep, void *objp, - unsigned long caller) -{ - struct array_cache *ac = cpu_cache_get(cachep); - - check_irq_off(); - kmemleak_free_recursive(objp, cachep->flags); - objp = cache_free_debugcheck(cachep, objp, caller); - - kmemcheck_slab_free(cachep, objp, cachep->object_size); - - /* - * Skip calling cache_free_alien() when the platform is not numa. - * This will avoid cache misses that happen while accessing slabp (which - * is per page memory reference) to get nodeid. Instead use a global - * variable to skip the call, which is mostly likely to be present in - * the cache. - */ - if (nr_online_nodes > 1 && cache_free_alien(cachep, objp)) - return; - - if (likely(ac->avail < ac->limit)) { - STATS_INC_FREEHIT(cachep); - } else { - STATS_INC_FREEMISS(cachep); - cache_flusharray(cachep, ac); - } - - ac_put_obj(cachep, ac, objp); -} - -/** - * kmem_cache_alloc - Allocate an object - * @cachep: The cache to allocate from. - * @flags: See kmalloc(). - * - * Allocate an object from this cache. The flags are only relevant - * if the cache has no available objects. - */ -void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags) -{ - void *ret = slab_alloc(cachep, flags, _RET_IP_); - - trace_kmem_cache_alloc(_RET_IP_, ret, - cachep->object_size, cachep->size, flags); - - return ret; -} -EXPORT_SYMBOL(kmem_cache_alloc); - -#ifdef CONFIG_TRACING -void * -kmem_cache_alloc_trace(struct kmem_cache *cachep, gfp_t flags, size_t size) -{ - void *ret; - - ret = slab_alloc(cachep, flags, _RET_IP_); - - trace_kmalloc(_RET_IP_, ret, - size, cachep->size, flags); - return ret; -} -EXPORT_SYMBOL(kmem_cache_alloc_trace); -#endif - -#ifdef CONFIG_NUMA -/** - * kmem_cache_alloc_node - Allocate an object on the specified node - * @cachep: The cache to allocate from. - * @flags: See kmalloc(). - * @nodeid: node number of the target node. - * - * Identical to kmem_cache_alloc but it will allocate memory on the given - * node, which can improve the performance for cpu bound structures. - * - * 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) -{ - void *ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_); - - trace_kmem_cache_alloc_node(_RET_IP_, ret, - cachep->object_size, cachep->size, - flags, nodeid); - - return ret; -} -EXPORT_SYMBOL(kmem_cache_alloc_node); - -#ifdef CONFIG_TRACING -void *kmem_cache_alloc_node_trace(struct kmem_cache *cachep, - gfp_t flags, - int nodeid, - size_t size) -{ - void *ret; - - ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_); - - trace_kmalloc_node(_RET_IP_, ret, - size, cachep->size, - flags, nodeid); - return ret; -} -EXPORT_SYMBOL(kmem_cache_alloc_node_trace); -#endif - -static __always_inline void * -__do_kmalloc_node(size_t size, gfp_t flags, int node, unsigned long caller) -{ - struct kmem_cache *cachep; - - cachep = kmalloc_slab(size, flags); - if (unlikely(ZERO_OR_NULL_PTR(cachep))) - return cachep; - return kmem_cache_alloc_node_trace(cachep, flags, node, size); -} - -#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_TRACING) -void *__kmalloc_node(size_t size, gfp_t flags, int node) -{ - return __do_kmalloc_node(size, flags, node, _RET_IP_); -} -EXPORT_SYMBOL(__kmalloc_node); - -void *__kmalloc_node_track_caller(size_t size, gfp_t flags, - int node, unsigned long 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, 0); -} -EXPORT_SYMBOL(__kmalloc_node); -#endif /* CONFIG_DEBUG_SLAB || CONFIG_TRACING */ -#endif /* CONFIG_NUMA */ - -/** - * __do_kmalloc - allocate memory - * @size: how many bytes of memory are required. - * @flags: the type of memory to allocate (see kmalloc). - * @caller: function caller for debug tracking of the caller - */ -static __always_inline void *__do_kmalloc(size_t size, gfp_t flags, - unsigned long caller) -{ - struct kmem_cache *cachep; - void *ret; - - /* If you want to save a few bytes .text space: replace - * __ with kmem_. - * Then kmalloc uses the uninlined functions instead of the inline - * functions. - */ - cachep = kmalloc_slab(size, flags); - if (unlikely(ZERO_OR_NULL_PTR(cachep))) - return cachep; - ret = slab_alloc(cachep, flags, caller); - - trace_kmalloc(caller, ret, - size, cachep->size, flags); - - return ret; -} - - -#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_TRACING) -void *__kmalloc(size_t size, gfp_t flags) -{ - return __do_kmalloc(size, flags, _RET_IP_); -} -EXPORT_SYMBOL(__kmalloc); - -void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller) -{ - return __do_kmalloc(size, flags, caller); -} -EXPORT_SYMBOL(__kmalloc_track_caller); - -#else -void *__kmalloc(size_t size, gfp_t flags) -{ - return __do_kmalloc(size, flags, 0); -} -EXPORT_SYMBOL(__kmalloc); -#endif - -/** - * kmem_cache_free - Deallocate an object - * @cachep: The cache the allocation was from. - * @objp: The previously allocated object. - * - * Free an object which was previously allocated from this - * cache. - */ -void kmem_cache_free(struct kmem_cache *cachep, void *objp) -{ - unsigned long flags; - cachep = cache_from_obj(cachep, objp); - if (!cachep) - return; - - local_irq_save(flags); - debug_check_no_locks_freed(objp, cachep->object_size); - if (!(cachep->flags & SLAB_DEBUG_OBJECTS)) - debug_check_no_obj_freed(objp, cachep->object_size); - __cache_free(cachep, objp, _RET_IP_); - local_irq_restore(flags); - - trace_kmem_cache_free(_RET_IP_, objp); -} -EXPORT_SYMBOL(kmem_cache_free); - -/** - * kfree - free previously allocated memory - * @objp: pointer returned by kmalloc. - * - * If @objp is NULL, no operation is performed. - * - * Don't free memory not originally allocated by kmalloc() - * or you will run into trouble. - */ -void kfree(const void *objp) -{ - struct kmem_cache *c; - unsigned long flags; - - trace_kfree(_RET_IP_, objp); - - if (unlikely(ZERO_OR_NULL_PTR(objp))) - return; - local_irq_save(flags); - kfree_debugcheck(objp); - c = virt_to_cache(objp); - debug_check_no_locks_freed(objp, c->object_size); - - debug_check_no_obj_freed(objp, c->object_size); - __cache_free(c, (void *)objp, _RET_IP_); - local_irq_restore(flags); -} -EXPORT_SYMBOL(kfree); - -/* - * This initializes kmem_cache_node or resizes various caches for all nodes. - */ -static int alloc_kmemlist(struct kmem_cache *cachep, gfp_t gfp) -{ - int node; - struct kmem_cache_node *n; - struct array_cache *new_shared; - struct array_cache **new_alien = NULL; - - for_each_online_node(node) { - - if (use_alien_caches) { - new_alien = alloc_alien_cache(node, cachep->limit, gfp); - if (!new_alien) - goto fail; - } - - new_shared = NULL; - if (cachep->shared) { - new_shared = alloc_arraycache(node, - cachep->shared*cachep->batchcount, - 0xbaadf00d, gfp); - if (!new_shared) { - free_alien_cache(new_alien); - goto fail; - } - } - - n = cachep->node[node]; - if (n) { - struct array_cache *shared = n->shared; - - spin_lock_irq(&n->list_lock); - - if (shared) - free_block(cachep, shared->entry, - shared->avail, node); - - n->shared = new_shared; - if (!n->alien) { - n->alien = new_alien; - new_alien = NULL; - } - n->free_limit = (1 + nr_cpus_node(node)) * - cachep->batchcount + cachep->num; - spin_unlock_irq(&n->list_lock); - kfree(shared); - free_alien_cache(new_alien); - continue; - } - n = kmalloc_node(sizeof(struct kmem_cache_node), gfp, node); - if (!n) { - free_alien_cache(new_alien); - kfree(new_shared); - goto fail; - } - - kmem_cache_node_init(n); - n->next_reap = jiffies + REAPTIMEOUT_LIST3 + - ((unsigned long)cachep) % REAPTIMEOUT_LIST3; - n->shared = new_shared; - n->alien = new_alien; - n->free_limit = (1 + nr_cpus_node(node)) * - cachep->batchcount + cachep->num; - cachep->node[node] = n; - } - return 0; - -fail: - if (!cachep->list.next) { - /* Cache is not active yet. Roll back what we did */ - node--; - while (node >= 0) { - if (cachep->node[node]) { - n = cachep->node[node]; - - kfree(n->shared); - free_alien_cache(n->alien); - kfree(n); - cachep->node[node] = NULL; - } - node--; - } - } - return -ENOMEM; -} - -struct ccupdate_struct { - struct kmem_cache *cachep; - struct array_cache *new[0]; -}; - -static void do_ccupdate_local(void *info) -{ - struct ccupdate_struct *new = info; - struct array_cache *old; - - check_irq_off(); - old = cpu_cache_get(new->cachep); - - new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()]; - new->new[smp_processor_id()] = old; -} - -/* Always called with the slab_mutex held */ -static int __do_tune_cpucache(struct kmem_cache *cachep, int limit, - int batchcount, int shared, gfp_t gfp) -{ - struct ccupdate_struct *new; - int i; - - new = kzalloc(sizeof(*new) + nr_cpu_ids * sizeof(struct array_cache *), - gfp); - if (!new) - return -ENOMEM; - - for_each_online_cpu(i) { - new->new[i] = alloc_arraycache(cpu_to_mem(i), limit, - batchcount, gfp); - if (!new->new[i]) { - for (i--; i >= 0; i--) - kfree(new->new[i]); - kfree(new); - return -ENOMEM; - } - } - new->cachep = cachep; - - on_each_cpu(do_ccupdate_local, (void *)new, 1); - - check_irq_on(); - cachep->batchcount = batchcount; - cachep->limit = limit; - cachep->shared = shared; - - for_each_online_cpu(i) { - struct array_cache *ccold = new->new[i]; - if (!ccold) - continue; - spin_lock_irq(&cachep->node[cpu_to_mem(i)]->list_lock); - free_block(cachep, ccold->entry, ccold->avail, cpu_to_mem(i)); - spin_unlock_irq(&cachep->node[cpu_to_mem(i)]->list_lock); - kfree(ccold); - } - kfree(new); - return alloc_kmemlist(cachep, gfp); -} - -static int do_tune_cpucache(struct kmem_cache *cachep, int limit, - int batchcount, int shared, gfp_t gfp) -{ - int ret; - struct kmem_cache *c = NULL; - int i = 0; - - ret = __do_tune_cpucache(cachep, limit, batchcount, shared, gfp); - - if (slab_state < FULL) - return ret; - - if ((ret < 0) || !is_root_cache(cachep)) - return ret; - - VM_BUG_ON(!mutex_is_locked(&slab_mutex)); - for_each_memcg_cache_index(i) { - c = cache_from_memcg(cachep, i); - if (c) - /* return value determined by the parent cache only */ - __do_tune_cpucache(c, limit, batchcount, shared, gfp); - } - - return ret; -} - -/* Called with slab_mutex held always */ -static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp) -{ - int err; - int limit = 0; - int shared = 0; - int batchcount = 0; - - if (!is_root_cache(cachep)) { - struct kmem_cache *root = memcg_root_cache(cachep); - limit = root->limit; - shared = root->shared; - batchcount = root->batchcount; - } - - if (limit && shared && batchcount) - goto skip_setup; - /* - * The head array serves three purposes: - * - create a LIFO ordering, i.e. return objects that are cache-warm - * - reduce the number of spinlock operations. - * - reduce the number of linked list operations on the slab and - * bufctl chains: array operations are cheaper. - * The numbers are guessed, we should auto-tune as described by - * Bonwick. - */ - if (cachep->size > 131072) - limit = 1; - else if (cachep->size > PAGE_SIZE) - limit = 8; - else if (cachep->size > 1024) - limit = 24; - else if (cachep->size > 256) - limit = 54; - else - limit = 120; - - /* - * CPU bound tasks (e.g. network routing) can exhibit cpu bound - * allocation behaviour: Most allocs on one cpu, most free operations - * on another cpu. For these cases, an efficient object passing between - * cpus is necessary. This is provided by a shared array. The array - * replaces Bonwick's magazine layer. - * On uniprocessor, it's functionally equivalent (but less efficient) - * to a larger limit. Thus disabled by default. - */ - shared = 0; - if (cachep->size <= PAGE_SIZE && num_possible_cpus() > 1) - shared = 8; - -#if DEBUG - /* - * With debugging enabled, large batchcount lead to excessively long - * periods with disabled local interrupts. Limit the batchcount - */ - if (limit > 32) - limit = 32; -#endif - batchcount = (limit + 1) / 2; -skip_setup: - err = do_tune_cpucache(cachep, limit, batchcount, shared, gfp); - if (err) - printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n", - cachep->name, -err); - return err; -} - -/* - * Drain an array if it contains any elements taking the node lock only if - * necessary. Note that the node listlock also protects the array_cache - * if drain_array() is used on the shared array. - */ -static void drain_array(struct kmem_cache *cachep, struct kmem_cache_node *n, - struct array_cache *ac, int force, int node) -{ - int tofree; - - if (!ac || !ac->avail) - return; - if (ac->touched && !force) { - ac->touched = 0; - } else { - spin_lock_irq(&n->list_lock); - if (ac->avail) { - tofree = force ? ac->avail : (ac->limit + 4) / 5; - if (tofree > ac->avail) - tofree = (ac->avail + 1) / 2; - free_block(cachep, ac->entry, tofree, node); - ac->avail -= tofree; - memmove(ac->entry, &(ac->entry[tofree]), - sizeof(void *) * ac->avail); - } - spin_unlock_irq(&n->list_lock); - } -} - -/** - * cache_reap - Reclaim memory from caches. - * @w: work descriptor - * - * Called from workqueue/eventd every few seconds. - * Purpose: - * - clear the per-cpu caches for this CPU. - * - return freeable pages to the main free memory pool. - * - * If we cannot acquire the cache chain mutex then just give up - we'll try - * again on the next iteration. - */ -static void cache_reap(struct work_struct *w) -{ - struct kmem_cache *searchp; - struct kmem_cache_node *n; - int node = numa_mem_id(); - struct delayed_work *work = to_delayed_work(w); - - if (!mutex_trylock(&slab_mutex)) - /* Give up. Setup the next iteration. */ - goto out; - - list_for_each_entry(searchp, &slab_caches, list) { - check_irq_on(); - - /* - * We only take the node lock if absolutely necessary and we - * have established with reasonable certainty that - * we can do some work if the lock was obtained. - */ - n = searchp->node[node]; - - reap_alien(searchp, n); - - drain_array(searchp, n, cpu_cache_get(searchp), 0, node); - - /* - * These are racy checks but it does not matter - * if we skip one check or scan twice. - */ - if (time_after(n->next_reap, jiffies)) - goto next; - - n->next_reap = jiffies + REAPTIMEOUT_LIST3; - - drain_array(searchp, n, n->shared, 0, node); - - if (n->free_touched) - n->free_touched = 0; - else { - int freed; - - freed = drain_freelist(searchp, n, (n->free_limit + - 5 * searchp->num - 1) / (5 * searchp->num)); - STATS_ADD_REAPED(searchp, freed); - } -next: - cond_resched(); - } - check_irq_on(); - mutex_unlock(&slab_mutex); - next_reap_node(); -out: - /* Set up the next iteration */ - schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC)); -} - -#ifdef CONFIG_SLABINFO -void get_slabinfo(struct kmem_cache *cachep, struct slabinfo *sinfo) -{ - struct slab *slabp; - unsigned long active_objs; - unsigned long num_objs; - unsigned long active_slabs = 0; - unsigned long num_slabs, free_objects = 0, shared_avail = 0; - const char *name; - char *error = NULL; - int node; - struct kmem_cache_node *n; - - active_objs = 0; - num_slabs = 0; - for_each_online_node(node) { - n = cachep->node[node]; - if (!n) - continue; - - check_irq_on(); - spin_lock_irq(&n->list_lock); - - list_for_each_entry(slabp, &n->slabs_full, list) { - if (slabp->inuse != cachep->num && !error) - error = "slabs_full accounting error"; - active_objs += cachep->num; - active_slabs++; - } - list_for_each_entry(slabp, &n->slabs_partial, list) { - if (slabp->inuse == cachep->num && !error) - error = "slabs_partial inuse accounting error"; - if (!slabp->inuse && !error) - error = "slabs_partial/inuse accounting error"; - active_objs += slabp->inuse; - active_slabs++; - } - list_for_each_entry(slabp, &n->slabs_free, list) { - if (slabp->inuse && !error) - error = "slabs_free/inuse accounting error"; - num_slabs++; - } - free_objects += n->free_objects; - if (n->shared) - shared_avail += n->shared->avail; - - spin_unlock_irq(&n->list_lock); - } - num_slabs += active_slabs; - num_objs = num_slabs * cachep->num; - if (num_objs - active_objs != free_objects && !error) - error = "free_objects accounting error"; - - name = cachep->name; - if (error) - printk(KERN_ERR "slab: cache %s error: %s\n", name, error); - - sinfo->active_objs = active_objs; - sinfo->num_objs = num_objs; - sinfo->active_slabs = active_slabs; - sinfo->num_slabs = num_slabs; - sinfo->shared_avail = shared_avail; - sinfo->limit = cachep->limit; - sinfo->batchcount = cachep->batchcount; - sinfo->shared = cachep->shared; - sinfo->objects_per_slab = cachep->num; - sinfo->cache_order = cachep->gfporder; -} - -void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *cachep) -{ -#if STATS - { /* node stats */ - unsigned long high = cachep->high_mark; - unsigned long allocs = cachep->num_allocations; - unsigned long grown = cachep->grown; - unsigned long reaped = cachep->reaped; - unsigned long errors = cachep->errors; - unsigned long max_freeable = cachep->max_freeable; - unsigned long node_allocs = cachep->node_allocs; - unsigned long node_frees = cachep->node_frees; - unsigned long overflows = cachep->node_overflow; - - seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu " - "%4lu %4lu %4lu %4lu %4lu", - allocs, high, grown, - reaped, errors, max_freeable, node_allocs, - node_frees, overflows); - } - /* cpu stats */ - { - unsigned long allochit = atomic_read(&cachep->allochit); - unsigned long allocmiss = atomic_read(&cachep->allocmiss); - unsigned long freehit = atomic_read(&cachep->freehit); - unsigned long freemiss = atomic_read(&cachep->freemiss); - - seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu", - allochit, allocmiss, freehit, freemiss); - } -#endif -} - -#define MAX_SLABINFO_WRITE 128 -/** - * slabinfo_write - Tuning for the slab allocator - * @file: unused - * @buffer: user buffer - * @count: data length - * @ppos: unused - */ -ssize_t slabinfo_write(struct file *file, const char __user *buffer, - size_t count, loff_t *ppos) -{ - char kbuf[MAX_SLABINFO_WRITE + 1], *tmp; - int limit, batchcount, shared, res; - struct kmem_cache *cachep; - - if (count > MAX_SLABINFO_WRITE) - return -EINVAL; - if (copy_from_user(&kbuf, buffer, count)) - return -EFAULT; - kbuf[MAX_SLABINFO_WRITE] = '\0'; - - tmp = strchr(kbuf, ' '); - if (!tmp) - return -EINVAL; - *tmp = '\0'; - tmp++; - if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3) - return -EINVAL; - - /* Find the cache in the chain of caches. */ - mutex_lock(&slab_mutex); - res = -EINVAL; - list_for_each_entry(cachep, &slab_caches, list) { - if (!strcmp(cachep->name, kbuf)) { - if (limit < 1 || batchcount < 1 || - batchcount > limit || shared < 0) { - res = 0; - } else { - res = do_tune_cpucache(cachep, limit, - batchcount, shared, - GFP_KERNEL); - } - break; - } - } - mutex_unlock(&slab_mutex); - if (res >= 0) - res = count; - return res; -} - -#ifdef CONFIG_DEBUG_SLAB_LEAK - -static void *leaks_start(struct seq_file *m, loff_t *pos) -{ - mutex_lock(&slab_mutex); - return seq_list_start(&slab_caches, *pos); -} - -static inline int add_caller(unsigned long *n, unsigned long v) -{ - unsigned long *p; - int l; - if (!v) - return 1; - l = n[1]; - p = n + 2; - while (l) { - int i = l/2; - unsigned long *q = p + 2 * i; - if (*q == v) { - q[1]++; - return 1; - } - if (*q > v) { - l = i; - } else { - p = q + 2; - l -= i + 1; - } - } - if (++n[1] == n[0]) - return 0; - memmove(p + 2, p, n[1] * 2 * sizeof(unsigned long) - ((void *)p - (void *)n)); - p[0] = v; - p[1] = 1; - return 1; -} - -static void handle_slab(unsigned long *n, struct kmem_cache *c, struct slab *s) -{ - void *p; - int i; - if (n[0] == n[1]) - return; - for (i = 0, p = s->s_mem; i < c->num; i++, p += c->size) { - if (slab_bufctl(s)[i] != BUFCTL_ACTIVE) - continue; - if (!add_caller(n, (unsigned long)*dbg_userword(c, p))) - return; - } -} - -static void show_symbol(struct seq_file *m, unsigned long address) -{ -#ifdef CONFIG_KALLSYMS - unsigned long offset, size; - char modname[MODULE_NAME_LEN], name[KSYM_NAME_LEN]; - - if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) { - seq_printf(m, "%s+%#lx/%#lx", name, offset, size); - if (modname[0]) - seq_printf(m, " [%s]", modname); - return; - } -#endif - seq_printf(m, "%p", (void *)address); -} - -static int leaks_show(struct seq_file *m, void *p) -{ - struct kmem_cache *cachep = list_entry(p, struct kmem_cache, list); - struct slab *slabp; - struct kmem_cache_node *n; - const char *name; - unsigned long *x = m->private; - int node; - int i; - - if (!(cachep->flags & SLAB_STORE_USER)) - return 0; - if (!(cachep->flags & SLAB_RED_ZONE)) - return 0; - - /* OK, we can do it */ - - x[1] = 0; - - for_each_online_node(node) { - n = cachep->node[node]; - if (!n) - continue; - - check_irq_on(); - spin_lock_irq(&n->list_lock); - - list_for_each_entry(slabp, &n->slabs_full, list) - handle_slab(x, cachep, slabp); - list_for_each_entry(slabp, &n->slabs_partial, list) - handle_slab(x, cachep, slabp); - spin_unlock_irq(&n->list_lock); - } - name = cachep->name; - if (x[0] == x[1]) { - /* Increase the buffer size */ - mutex_unlock(&slab_mutex); - m->private = kzalloc(x[0] * 4 * sizeof(unsigned long), GFP_KERNEL); - if (!m->private) { - /* Too bad, we are really out */ - m->private = x; - mutex_lock(&slab_mutex); - return -ENOMEM; - } - *(unsigned long *)m->private = x[0] * 2; - kfree(x); - mutex_lock(&slab_mutex); - /* Now make sure this entry will be retried */ - m->count = m->size; - return 0; - } - for (i = 0; i < x[1]; i++) { - seq_printf(m, "%s: %lu ", name, x[2*i+3]); - show_symbol(m, x[2*i+2]); - seq_putc(m, '\n'); - } - - return 0; -} - -static const struct seq_operations slabstats_op = { - .start = leaks_start, - .next = slab_next, - .stop = slab_stop, - .show = leaks_show, -}; - -static int slabstats_open(struct inode *inode, struct file *file) -{ - unsigned long *n = kzalloc(PAGE_SIZE, GFP_KERNEL); - int ret = -ENOMEM; - if (n) { - ret = seq_open(file, &slabstats_op); - if (!ret) { - struct seq_file *m = file->private_data; - *n = PAGE_SIZE / (2 * sizeof(unsigned long)); - m->private = n; - n = NULL; - } - kfree(n); - } - return ret; -} - -static const struct file_operations proc_slabstats_operations = { - .open = slabstats_open, - .read = seq_read, - .llseek = seq_lseek, - .release = seq_release_private, -}; -#endif - -static int __init slab_proc_init(void) -{ -#ifdef CONFIG_DEBUG_SLAB_LEAK - proc_create("slab_allocators", 0, NULL, &proc_slabstats_operations); -#endif - return 0; -} -module_init(slab_proc_init); -#endif - -/** - * ksize - get the actual amount of memory allocated for a given object - * @objp: Pointer to the object - * - * kmalloc may internally round up allocations and return more memory - * than requested. ksize() can be used to determine the actual amount of - * memory allocated. The caller may use this additional memory, even though - * a smaller amount of memory was initially specified with the kmalloc call. - * The caller must guarantee that objp points to a valid object previously - * allocated with either kmalloc() or kmem_cache_alloc(). The object - * must not be freed during the duration of the call. - */ -size_t ksize(const void *objp) -{ - BUG_ON(!objp); - if (unlikely(objp == ZERO_SIZE_PTR)) - return 0; - - return virt_to_cache(objp)->object_size; -} -EXPORT_SYMBOL(ksize); |