--- /dev/null
+/*
+ * 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
+
+#define FREELIST_BYTE_INDEX (((PAGE_SIZE >> BITS_PER_BYTE) \
+ <= SLAB_OBJ_MIN_SIZE) ? 1 : 0)
+
+#if FREELIST_BYTE_INDEX
+typedef unsigned char freelist_idx_t;
+#else
+typedef unsigned short freelist_idx_t;
+#endif
+
+#define SLAB_OBJ_MAX_NUM ((1 << sizeof(freelist_idx_t) * BITS_PER_BYTE) - 1)
+
+/*
+ * true if a page was allocated from pfmemalloc reserves for network-based
+ * swap
+ */
+static bool pfmemalloc_active __read_mostly;
+
+/*
+ * 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;
+ 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
+ */
+};
+
+struct alien_cache {
+ spinlock_t lock;
+ struct array_cache ac;
+};
+
+#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 (2 * MAX_NUMNODES)
+static struct kmem_cache_node __initdata init_kmem_cache_node[NUM_INIT_LISTS];
+#define CACHE_CACHE 0
+#define SIZE_NODE (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, struct list_head *list);
+static void slabs_destroy(struct kmem_cache *cachep, struct list_head *list);
+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_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(&get_node(cachep, 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_AC (2*HZ)
+#define REAPTIMEOUT_NODE (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
+
+#define OBJECT_FREE (0)
+#define OBJECT_ACTIVE (1)
+
+#ifdef CONFIG_DEBUG_SLAB_LEAK
+
+static void set_obj_status(struct page *page, int idx, int val)
+{
+ int freelist_size;
+ char *status;
+ struct kmem_cache *cachep = page->slab_cache;
+
+ freelist_size = cachep->num * sizeof(freelist_idx_t);
+ status = (char *)page->freelist + freelist_size;
+ status[idx] = val;
+}
+
+static inline unsigned int get_obj_status(struct page *page, int idx)
+{
+ int freelist_size;
+ char *status;
+ struct kmem_cache *cachep = page->slab_cache;
+
+ freelist_size = cachep->num * sizeof(freelist_idx_t);
+ status = (char *)page->freelist + freelist_size;
+
+ return status[idx];
+}
+
+#else
+static inline void set_obj_status(struct page *page, int idx, int val) {}
+
+#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 void *index_to_obj(struct kmem_cache *cache, struct page *page,
+ unsigned int idx)
+{
+ return page->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 page *page, void *obj)
+{
+ u32 offset = (obj - page->s_mem);
+ return reciprocal_divide(offset, cache->reciprocal_buffer_size);
+}
+
+/* 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
+
+static DEFINE_PER_CPU(struct delayed_work, slab_reap_work);
+
+static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
+{
+ return this_cpu_ptr(cachep->cpu_cache);
+}
+
+static size_t calculate_freelist_size(int nr_objs, size_t align)
+{
+ size_t freelist_size;
+
+ freelist_size = nr_objs * sizeof(freelist_idx_t);
+ if (IS_ENABLED(CONFIG_DEBUG_SLAB_LEAK))
+ freelist_size += nr_objs * sizeof(char);
+
+ if (align)
+ freelist_size = ALIGN(freelist_size, align);
+
+ return freelist_size;
+}
+
+static int calculate_nr_objs(size_t slab_size, size_t buffer_size,
+ size_t idx_size, size_t align)
+{
+ int nr_objs;
+ size_t remained_size;
+ size_t freelist_size;
+ int extra_space = 0;
+
+ if (IS_ENABLED(CONFIG_DEBUG_SLAB_LEAK))
+ extra_space = sizeof(char);
+ /*
+ * 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 / (buffer_size + idx_size + extra_space);
+
+ /*
+ * This calculated number will be either the right
+ * amount, or one greater than what we want.
+ */
+ remained_size = slab_size - nr_objs * buffer_size;
+ freelist_size = calculate_freelist_size(nr_objs, align);
+ if (remained_size < freelist_size)
+ nr_objs--;
+
+ return nr_objs;
+}
+
+/*
+ * 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:
+ *
+ * - One unsigned int 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;
+
+ } else {
+ nr_objs = calculate_nr_objs(slab_size, buffer_size,
+ sizeof(freelist_idx_t), align);
+ mgmt_size = calculate_freelist_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 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 void init_arraycache(struct array_cache *ac, int limit, int batch)
+{
+ /*
+ * 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(ac);
+ if (ac) {
+ ac->avail = 0;
+ ac->limit = limit;
+ ac->batchcount = batch;
+ ac->touched = 0;
+ }
+}
+
+static struct array_cache *alloc_arraycache(int node, int entries,
+ int batchcount, gfp_t gfp)
+{
+ size_t memsize = sizeof(void *) * entries + sizeof(struct array_cache);
+ struct array_cache *ac = NULL;
+
+ ac = kmalloc_node(memsize, gfp, node);
+ init_arraycache(ac, entries, batchcount);
+ return ac;
+}
+
+static inline bool is_slab_pfmemalloc(struct page *page)
+{
+ 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 = get_node(cachep, numa_mem_id());
+ struct page *page;
+ unsigned long flags;
+
+ if (!pfmemalloc_active)
+ return;
+
+ spin_lock_irqsave(&n->list_lock, flags);
+ list_for_each_entry(page, &n->slabs_full, lru)
+ if (is_slab_pfmemalloc(page))
+ goto out;
+
+ list_for_each_entry(page, &n->slabs_partial, lru)
+ if (is_slab_pfmemalloc(page))
+ goto out;
+
+ list_for_each_entry(page, &n->slabs_free, lru)
+ if (is_slab_pfmemalloc(page))
+ 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 = get_node(cachep, numa_mem_id());
+ if (!list_empty(&n->slabs_free) && force_refill) {
+ struct page *page = virt_to_head_page(objp);
+ ClearPageSlabPfmemalloc(page);
+ 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 noinline 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 alien_cache **alloc_alien_cache(int node,
+ int limit, gfp_t gfp)
+{
+ return (struct alien_cache **)BAD_ALIEN_MAGIC;
+}
+
+static inline void free_alien_cache(struct alien_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;
+}
+
+static inline gfp_t gfp_exact_node(gfp_t flags)
+{
+ return flags;
+}
+
+#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 alien_cache *__alloc_alien_cache(int node, int entries,
+ int batch, gfp_t gfp)
+{
+ size_t memsize = sizeof(void *) * entries + sizeof(struct alien_cache);
+ struct alien_cache *alc = NULL;
+
+ alc = kmalloc_node(memsize, gfp, node);
+ init_arraycache(&alc->ac, entries, batch);
+ spin_lock_init(&alc->lock);
+ return alc;
+}
+
+static struct alien_cache **alloc_alien_cache(int node, int limit, gfp_t gfp)
+{
+ struct alien_cache **alc_ptr;
+ size_t memsize = sizeof(void *) * nr_node_ids;
+ int i;
+
+ if (limit > 1)
+ limit = 12;
+ alc_ptr = kzalloc_node(memsize, gfp, node);
+ if (!alc_ptr)
+ return NULL;
+
+ for_each_node(i) {
+ if (i == node || !node_online(i))
+ continue;
+ alc_ptr[i] = __alloc_alien_cache(node, limit, 0xbaadf00d, gfp);
+ if (!alc_ptr[i]) {
+ for (i--; i >= 0; i--)
+ kfree(alc_ptr[i]);
+ kfree(alc_ptr);
+ return NULL;
+ }
+ }
+ return alc_ptr;
+}
+
+static void free_alien_cache(struct alien_cache **alc_ptr)
+{
+ int i;
+
+ if (!alc_ptr)
+ return;
+ for_each_node(i)
+ kfree(alc_ptr[i]);
+ kfree(alc_ptr);
+}
+
+static void __drain_alien_cache(struct kmem_cache *cachep,
+ struct array_cache *ac, int node,
+ struct list_head *list)
+{
+ struct kmem_cache_node *n = get_node(cachep, 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, list);
+ 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 alien_cache *alc = n->alien[node];
+ struct array_cache *ac;
+
+ if (alc) {
+ ac = &alc->ac;
+ if (ac->avail && spin_trylock_irq(&alc->lock)) {
+ LIST_HEAD(list);
+
+ __drain_alien_cache(cachep, ac, node, &list);
+ spin_unlock_irq(&alc->lock);
+ slabs_destroy(cachep, &list);
+ }
+ }
+ }
+}
+
+static void drain_alien_cache(struct kmem_cache *cachep,
+ struct alien_cache **alien)
+{
+ int i = 0;
+ struct alien_cache *alc;
+ struct array_cache *ac;
+ unsigned long flags;
+
+ for_each_online_node(i) {
+ alc = alien[i];
+ if (alc) {
+ LIST_HEAD(list);
+
+ ac = &alc->ac;
+ spin_lock_irqsave(&alc->lock, flags);
+ __drain_alien_cache(cachep, ac, i, &list);
+ spin_unlock_irqrestore(&alc->lock, flags);
+ slabs_destroy(cachep, &list);
+ }
+ }
+}
+
+static int __cache_free_alien(struct kmem_cache *cachep, void *objp,
+ int node, int page_node)
+{
+ struct kmem_cache_node *n;
+ struct alien_cache *alien = NULL;
+ struct array_cache *ac;
+ LIST_HEAD(list);
+
+ n = get_node(cachep, node);
+ STATS_INC_NODEFREES(cachep);
+ if (n->alien && n->alien[page_node]) {
+ alien = n->alien[page_node];
+ ac = &alien->ac;
+ spin_lock(&alien->lock);
+ if (unlikely(ac->avail == ac->limit)) {
+ STATS_INC_ACOVERFLOW(cachep);
+ __drain_alien_cache(cachep, ac, page_node, &list);
+ }
+ ac_put_obj(cachep, ac, objp);
+ spin_unlock(&alien->lock);
+ slabs_destroy(cachep, &list);
+ } else {
+ n = get_node(cachep, page_node);
+ spin_lock(&n->list_lock);
+ free_block(cachep, &objp, 1, page_node, &list);
+ spin_unlock(&n->list_lock);
+ slabs_destroy(cachep, &list);
+ }
+ return 1;
+}
+
+static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
+{
+ int page_node = page_to_nid(virt_to_page(objp));
+ int node = numa_mem_id();
+ /*
+ * Make sure we are not freeing a object from another node to the array
+ * cache on this cpu.
+ */
+ if (likely(node == page_node))
+ return 0;
+
+ return __cache_free_alien(cachep, objp, node, page_node);
+}
+
+/*
+ * Construct gfp mask to allocate from a specific node but do not invoke reclaim
+ * or warn about failures.
+ */
+static inline gfp_t gfp_exact_node(gfp_t flags)
+{
+ return (flags | __GFP_THISNODE | __GFP_NOWARN) & ~__GFP_WAIT;
+}
+#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 size_t memsize = sizeof(struct kmem_cache_node);
+
+ list_for_each_entry(cachep, &slab_caches, list) {
+ /*
+ * Set up the kmem_cache_node for cpu before we can
+ * begin anything. Make sure some other cpu on this
+ * node has not already allocated this
+ */
+ n = get_node(cachep, node);
+ if (!n) {
+ n = kmalloc_node(memsize, GFP_KERNEL, node);
+ if (!n)
+ return -ENOMEM;
+ kmem_cache_node_init(n);
+ n->next_reap = jiffies + REAPTIMEOUT_NODE +
+ ((unsigned long)cachep) % REAPTIMEOUT_NODE;
+
+ /*
+ * The kmem_cache_nodes don't come and go as CPUs
+ * come and go. slab_mutex is sufficient
+ * protection here.
+ */
+ cachep->node[node] = n;
+ }
+
+ spin_lock_irq(&n->list_lock);
+ n->free_limit =
+ (1 + nr_cpus_node(node)) *
+ cachep->batchcount + cachep->num;
+ spin_unlock_irq(&n->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 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 alien_cache **alien;
+ LIST_HEAD(list);
+
+ n = get_node(cachep, node);
+ if (!n)
+ continue;
+
+ spin_lock_irq(&n->list_lock);
+
+ /* Free limit for this kmem_cache_node */
+ n->free_limit -= cachep->batchcount;
+
+ /* cpu is dead; no one can alloc from it. */
+ nc = per_cpu_ptr(cachep->cpu_cache, cpu);
+ if (nc) {
+ free_block(cachep, nc->entry, nc->avail, node, &list);
+ nc->avail = 0;
+ }
+
+ if (!cpumask_empty(mask)) {
+ spin_unlock_irq(&n->list_lock);
+ goto free_slab;
+ }
+
+ shared = n->shared;
+ if (shared) {
+ free_block(cachep, shared->entry,
+ shared->avail, node, &list);
+ 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_slab:
+ slabs_destroy(cachep, &list);
+ }
+ /*
+ * 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 = get_node(cachep, node);
+ if (!n)
+ continue;
+ drain_freelist(cachep, n, slabs_tofree(cachep, n));
+ }
+}
+
+static int 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 *shared = NULL;
+ struct alien_cache **alien = NULL;
+
+ if (cachep->shared) {
+ shared = alloc_arraycache(node,
+ cachep->shared * cachep->batchcount,
+ 0xbaadf00d, GFP_KERNEL);
+ if (!shared)
+ goto bad;
+ }
+ if (use_alien_caches) {
+ alien = alloc_alien_cache(node, cachep->limit, GFP_KERNEL);
+ if (!alien) {
+ kfree(shared);
+ goto bad;
+ }
+ }
+ n = get_node(cachep, 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);
+ }
+
+ return 0;
+bad:
+ cpuup_canceled(cpu);
+ return -ENOMEM;
+}
+
+static int 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 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 = get_node(cachep, 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_NODE +
+ ((unsigned long)cachep) % REAPTIMEOUT_NODE;
+ }
+}
+
+/*
+ * Initialisation. Called after the page allocator have been initialised and
+ * before smp_init().
+ */
+void __init kmem_cache_init(void)
+{
+ int i;
+
+ BUILD_BUG_ON(sizeof(((struct page *)NULL)->lru) <
+ sizeof(struct rcu_head));
+ kmem_cache = &kmem_cache_boot;
+
+ 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]);
+
+ /*
+ * 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, node) +
+ nr_node_ids * sizeof(struct kmem_cache_node *),
+ SLAB_HWCACHE_ALIGN);
+ list_add(&kmem_cache->list, &slab_caches);
+ slab_state = PARTIAL;
+
+ /*
+ * Initialize the caches that provide memory for the kmem_cache_node
+ * structures first. Without this, further allocations will bug.
+ */
+ kmalloc_caches[INDEX_NODE] = create_kmalloc_cache("kmalloc-node",
+ kmalloc_size(INDEX_NODE), ARCH_KMALLOC_FLAGS);
+ slab_state = PARTIAL_NODE;
+
+ slab_early_init = 0;
+
+ /* 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_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);
+
+ /* 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)
+{
+#if DEBUG
+ struct kmem_cache_node *n;
+ struct page *page;
+ unsigned long flags;
+ int node;
+ static DEFINE_RATELIMIT_STATE(slab_oom_rs, DEFAULT_RATELIMIT_INTERVAL,
+ DEFAULT_RATELIMIT_BURST);
+
+ if ((gfpflags & __GFP_NOWARN) || !__ratelimit(&slab_oom_rs))
+ return;
+
+ 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_kmem_cache_node(cachep, node, n) {
+ unsigned long active_objs = 0, num_objs = 0, free_objects = 0;
+ unsigned long active_slabs = 0, num_slabs = 0;
+
+ spin_lock_irqsave(&n->list_lock, flags);
+ list_for_each_entry(page, &n->slabs_full, lru) {
+ active_objs += cachep->num;
+ active_slabs++;
+ }
+ list_for_each_entry(page, &n->slabs_partial, lru) {
+ active_objs += page->active;
+ active_slabs++;
+ }
+ list_for_each_entry(page, &n->slabs_free, lru)
+ 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);
+ }
+#endif
+}
+
+/*
+ * Interface to system's page allocator. No need to hold the
+ * kmem_cache_node ->list_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 struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
+ int nodeid)
+{
+ struct page *page;
+ int nr_pages;
+
+ flags |= cachep->allocflags;
+ if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
+ flags |= __GFP_RECLAIMABLE;
+
+ if (memcg_charge_slab(cachep, flags, cachep->gfporder))
+ return NULL;
+
+ page = alloc_pages_exact_node(nodeid, flags | __GFP_NOTRACK, cachep->gfporder);
+ if (!page) {
+ memcg_uncharge_slab(cachep, cachep->gfporder);
+ 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);
+ __SetPageSlab(page);
+ if (page->pfmemalloc)
+ SetPageSlabPfmemalloc(page);
+
+ 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;
+}
+
+/*
+ * Interface to system's page release.
+ */
+static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
+{
+ const unsigned long nr_freed = (1 << cachep->gfporder);
+
+ 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);
+
+ BUG_ON(!PageSlab(page));
+ __ClearPageSlabPfmemalloc(page);
+ __ClearPageSlab(page);
+ page_mapcount_reset(page);
+ page->mapping = NULL;
+
+ if (current->reclaim_state)
+ current->reclaim_state->reclaimed_slab += nr_freed;
+ __free_pages(page, cachep->gfporder);
+ memcg_uncharge_slab(cachep, cachep->gfporder);
+}
+
+static void kmem_rcu_free(struct rcu_head *head)
+{
+ struct kmem_cache *cachep;
+ struct page *page;
+
+ page = container_of(head, struct page, rcu_head);
+ cachep = page->slab_cache;
+
+ kmem_freepages(cachep, page);
+}
+
+#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 page *page = virt_to_head_page(objp);
+ unsigned int objnr;
+
+ objnr = obj_to_index(cachep, page, objp);
+ if (objnr) {
+ objp = index_to_obj(cachep, page, 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, page, 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 page *page)
+{
+ int i;
+ for (i = 0; i < cachep->num; i++) {
+ void *objp = index_to_obj(cachep, page, 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 page *page)
+{
+}
+#endif
+
+/**
+ * slab_destroy - destroy and release all objects in a slab
+ * @cachep: cache pointer being destroyed
+ * @page: page pointer being destroyed
+ *
+ * Destroy all the objs in a slab page, and release the mem back to the system.
+ * Before calling the slab page must have been unlinked from the cache. The
+ * kmem_cache_node ->list_lock is not held/needed.
+ */
+static void slab_destroy(struct kmem_cache *cachep, struct page *page)
+{
+ void *freelist;
+
+ freelist = page->freelist;
+ slab_destroy_debugcheck(cachep, page);
+ if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
+ struct rcu_head *head;
+
+ /*
+ * RCU free overloads the RCU head over the LRU.
+ * slab_page has been overloeaded over the LRU,
+ * however it is not used from now on so that
+ * we can use it safely.
+ */
+ head = (void *)&page->rcu_head;
+ call_rcu(head, kmem_rcu_free);
+
+ } else {
+ kmem_freepages(cachep, page);
+ }
+
+ /*
+ * From now on, we don't use freelist
+ * although actual page can be freed in rcu context
+ */
+ if (OFF_SLAB(cachep))
+ kmem_cache_free(cachep->freelist_cache, freelist);
+}
+
+static void slabs_destroy(struct kmem_cache *cachep, struct list_head *list)
+{
+ struct page *page, *n;
+
+ list_for_each_entry_safe(page, n, list, lru) {
+ list_del(&page->lru);
+ slab_destroy(cachep, page);
+ }
+}
+
+/**
+ * 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;
+
+ /* Can't handle number of objects more than SLAB_OBJ_MAX_NUM */
+ if (num > SLAB_OBJ_MAX_NUM)
+ break;
+
+ if (flags & CFLGS_OFF_SLAB) {
+ size_t freelist_size_per_obj = sizeof(freelist_idx_t);
+ /*
+ * Max number of objs-per-slab for caches which
+ * use off-slab slabs. Needed to avoid a possible
+ * looping condition in cache_grow().
+ */
+ if (IS_ENABLED(CONFIG_DEBUG_SLAB_LEAK))
+ freelist_size_per_obj += sizeof(char);
+ offslab_limit = size;
+ offslab_limit /= freelist_size_per_obj;
+
+ 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 struct array_cache __percpu *alloc_kmem_cache_cpus(
+ struct kmem_cache *cachep, int entries, int batchcount)
+{
+ int cpu;
+ size_t size;
+ struct array_cache __percpu *cpu_cache;
+
+ size = sizeof(void *) * entries + sizeof(struct array_cache);
+ cpu_cache = __alloc_percpu(size, sizeof(void *));
+
+ if (!cpu_cache)
+ return NULL;
+
+ for_each_possible_cpu(cpu) {
+ init_arraycache(per_cpu_ptr(cpu_cache, cpu),
+ entries, batchcount);
+ }
+
+ return cpu_cache;
+}
+
+static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp)
+{
+ if (slab_state >= FULL)
+ return enable_cpucache(cachep, gfp);
+
+ cachep->cpu_cache = alloc_kmem_cache_cpus(cachep, 1, 1);
+ if (!cachep->cpu_cache)
+ return 1;
+
+ if (slab_state == DOWN) {
+ /* Creation of first cache (kmem_cache). */
+ set_up_node(kmem_cache, CACHE_CACHE);
+ } else if (slab_state == PARTIAL) {
+ /* For kmem_cache_node */
+ set_up_node(cachep, SIZE_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_NODE +
+ ((unsigned long)cachep) % REAPTIMEOUT_NODE;
+
+ 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;
+}
+
+unsigned long kmem_cache_flags(unsigned long object_size,
+ unsigned long flags, const char *name,
+ void (*ctor)(void *))
+{
+ return flags;
+}
+
+struct kmem_cache *
+__kmem_cache_alias(const char *name, size_t size, size_t align,
+ unsigned long flags, void (*ctor)(void *))
+{
+ struct kmem_cache *cachep;
+
+ cachep = find_mergeable(size, align, flags, name, ctor);
+ if (cachep) {
+ cachep->refcount++;
+
+ /*
+ * Adjust the object sizes so that we clear
+ * the complete object on kzalloc.
+ */
+ cachep->object_size = max_t(int, cachep->object_size, size);
+ }
+ return cachep;
+}
+
+/**
+ * __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, freelist_size;
+ size_t ralign = BYTES_PER_WORD;
+ 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);
+ }
+
+ 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;
+
+#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 >> 5)) && !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);
+ /*
+ * We should restrict the number of objects in a slab to implement
+ * byte sized index. Refer comment on SLAB_OBJ_MIN_SIZE definition.
+ */
+ if (FREELIST_BYTE_INDEX && size < SLAB_OBJ_MIN_SIZE)
+ size = ALIGN(SLAB_OBJ_MIN_SIZE, cachep->align);
+
+ left_over = calculate_slab_order(cachep, size, cachep->align, flags);
+
+ if (!cachep->num)
+ return -E2BIG;
+
+ freelist_size = calculate_freelist_size(cachep->num, 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 >= freelist_size) {
+ flags &= ~CFLGS_OFF_SLAB;
+ left_over -= freelist_size;
+ }
+
+ if (flags & CFLGS_OFF_SLAB) {
+ /* really off slab. No need for manual alignment */
+ freelist_size = calculate_freelist_size(cachep->num, 0);
+
+#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->freelist_size = freelist_size;
+ cachep->flags = flags;
+ cachep->allocflags = __GFP_COMP;
+ 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->freelist_cache = kmalloc_slab(freelist_size, 0u);
+ /*
+ * This is a possibility for one of the kmalloc_{dma,}_caches.
+ * But since we go off slab only for object size greater than
+ * PAGE_SIZE/8, and kmalloc_{dma,}_caches get 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->freelist_cache));
+ }
+
+ err = setup_cpu_cache(cachep, gfp);
+ if (err) {
+ __kmem_cache_shutdown(cachep);
+ return err;
+ }
+
+ 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(&get_node(cachep, 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(&get_node(cachep, 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();
+ struct kmem_cache_node *n;
+ LIST_HEAD(list);
+
+ check_irq_off();
+ ac = cpu_cache_get(cachep);
+ n = get_node(cachep, node);
+ spin_lock(&n->list_lock);
+ free_block(cachep, ac->entry, ac->avail, node, &list);
+ spin_unlock(&n->list_lock);
+ slabs_destroy(cachep, &list);
+ 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_kmem_cache_node(cachep, node, n)
+ if (n->alien)
+ drain_alien_cache(cachep, n->alien);
+
+ for_each_kmem_cache_node(cachep, node, 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 page *page;
+
+ 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;
+ }
+
+ page = list_entry(p, struct page, lru);
+#if DEBUG
+ BUG_ON(page->active);
+#endif
+ list_del(&page->lru);
+ /*
+ * 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, page);
+ nr_freed++;
+ }
+out:
+ return nr_freed;
+}
+
+int __kmem_cache_shrink(struct kmem_cache *cachep, bool deactivate)
+{
+ int ret = 0;
+ int node;
+ struct kmem_cache_node *n;
+
+ drain_cpu_caches(cachep);
+
+ check_irq_on();
+ for_each_kmem_cache_node(cachep, node, n) {
+ drain_freelist(cachep, n, slabs_tofree(cachep, n));
+
+ ret += !list_empty(&n->slabs_full) ||
+ !list_empty(&n->slabs_partial);
+ }
+ return (ret ? 1 : 0);
+}
+
+int __kmem_cache_shutdown(struct kmem_cache *cachep)
+{
+ int i;
+ struct kmem_cache_node *n;
+ int rc = __kmem_cache_shrink(cachep, false);
+
+ if (rc)
+ return rc;
+
+ free_percpu(cachep->cpu_cache);
+
+ /* NUMA: free the node structures */
+ for_each_kmem_cache_node(cachep, i, n) {
+ kfree(n->shared);
+ free_alien_cache(n->alien);
+ kfree(n);
+ cachep->node[i] = NULL;
+ }
+ return 0;
+}
+
+/*
+ * Get the memory for a slab management obj.
+ *
+ * For a slab cache when the slab descriptor is off-slab, the
+ * slab descriptor can't come from the same cache which is being created,
+ * Because if it is the case, that means we defer the creation of
+ * the kmalloc_{dma,}_cache of size sizeof(slab descriptor) to this point.
+ * And we eventually call down to __kmem_cache_create(), which
+ * in turn looks up in the kmalloc_{dma,}_caches for the disired-size one.
+ * This is a "chicken-and-egg" problem.
+ *
+ * So the off-slab slab descriptor shall come from the kmalloc_{dma,}_caches,
+ * which are all initialized during kmem_cache_init().
+ */
+static void *alloc_slabmgmt(struct kmem_cache *cachep,
+ struct page *page, int colour_off,
+ gfp_t local_flags, int nodeid)
+{
+ void *freelist;
+ void *addr = page_address(page);
+
+ if (OFF_SLAB(cachep)) {
+ /* Slab management obj is off-slab. */
+ freelist = kmem_cache_alloc_node(cachep->freelist_cache,
+ local_flags, nodeid);
+ if (!freelist)
+ return NULL;
+ } else {
+ freelist = addr + colour_off;
+ colour_off += cachep->freelist_size;
+ }
+ page->active = 0;
+ page->s_mem = addr + colour_off;
+ return freelist;
+}
+
+static inline freelist_idx_t get_free_obj(struct page *page, unsigned int idx)
+{
+ return ((freelist_idx_t *)page->freelist)[idx];
+}
+
+static inline void set_free_obj(struct page *page,
+ unsigned int idx, freelist_idx_t val)
+{
+ ((freelist_idx_t *)(page->freelist))[idx] = val;
+}
+
+static void cache_init_objs(struct kmem_cache *cachep,
+ struct page *page)
+{
+ int i;
+
+ for (i = 0; i < cachep->num; i++) {
+ void *objp = index_to_obj(cachep, page, 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
+ set_obj_status(page, i, OBJECT_FREE);
+ set_free_obj(page, i, i);
+ }
+}
+
+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 page *page,
+ int nodeid)
+{
+ void *objp;
+
+ objp = index_to_obj(cachep, page, get_free_obj(page, page->active));
+ page->active++;
+#if DEBUG
+ WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid);
+#endif
+
+ return objp;
+}
+
+static void slab_put_obj(struct kmem_cache *cachep, struct page *page,
+ void *objp, int nodeid)
+{
+ unsigned int objnr = obj_to_index(cachep, page, objp);
+#if DEBUG
+ unsigned int i;
+
+ /* Verify that the slab belongs to the intended node */
+ WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid);
+
+ /* Verify double free bug */
+ for (i = page->active; i < cachep->num; i++) {
+ if (get_free_obj(page, i) == objnr) {
+ printk(KERN_ERR "slab: double free detected in cache "
+ "'%s', objp %p\n", cachep->name, objp);
+ BUG();
+ }
+ }
+#endif
+ page->active--;
+ set_free_obj(page, page->active, objnr);
+}
+
+/*
+ * 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 page *page,
+ void *freelist)
+{
+ page->slab_cache = cache;
+ page->freelist = freelist;
+}
+
+/*
+ * 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, struct page *page)
+{
+ void *freelist;
+ 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().
+ */
+ if (unlikely(flags & GFP_SLAB_BUG_MASK)) {
+ pr_emerg("gfp: %u\n", flags & GFP_SLAB_BUG_MASK);
+ BUG();
+ }
+ 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 = get_node(cachep, 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 (!page)
+ page = kmem_getpages(cachep, local_flags, nodeid);
+ if (!page)
+ goto failed;
+
+ /* Get slab management. */
+ freelist = alloc_slabmgmt(cachep, page, offset,
+ local_flags & ~GFP_CONSTRAINT_MASK, nodeid);
+ if (!freelist)
+ goto opps1;
+
+ slab_map_pages(cachep, page, freelist);
+
+ cache_init_objs(cachep, page);
+
+ if (local_flags & __GFP_WAIT)
+ local_irq_disable();
+ check_irq_off();
+ spin_lock(&n->list_lock);
+
+ /* Make slab active. */
+ list_add_tail(&page->lru, &(n->slabs_free));
+ STATS_INC_GROWN(cachep);
+ n->free_objects += cachep->num;
+ spin_unlock(&n->list_lock);
+ return 1;
+opps1:
+ kmem_freepages(cachep, page);
+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)
+{
+ unsigned int objnr;
+ struct page *page;
+
+ BUG_ON(virt_to_cache(objp) != cachep);
+
+ objp -= obj_offset(cachep);
+ kfree_debugcheck(objp);
+ page = virt_to_head_page(objp);
+
+ 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, page, objp);
+
+ BUG_ON(objnr >= cachep->num);
+ BUG_ON(objp != index_to_obj(cachep, page, objnr));
+
+ set_obj_status(page, objnr, OBJECT_FREE);
+ 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;
+}
+
+#else
+#define kfree_debugcheck(x) do { } while(0)
+#define cache_free_debugcheck(x,objp,z) (objp)
+#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 = get_node(cachep, 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 page *page;
+ /* 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;
+ }
+
+ page = list_entry(entry, struct page, lru);
+ 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(page->active >= cachep->num);
+
+ while (page->active < cachep->num && batchcount--) {
+ STATS_INC_ALLOCED(cachep);
+ STATS_INC_ACTIVE(cachep);
+ STATS_SET_HIGH(cachep);
+
+ ac_put_obj(cachep, ac, slab_get_obj(cachep, page,
+ node));
+ }
+
+ /* move slabp to correct slabp list: */
+ list_del(&page->lru);
+ if (page->active == cachep->num)
+ list_add(&page->lru, &n->slabs_full);
+ else
+ list_add(&page->lru, &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, gfp_exact_node(flags), 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)
+{
+ struct page *page;
+
+ 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;
+ }
+
+ page = virt_to_head_page(objp);
+ set_obj_status(page, obj_to_index(cachep, page, objp), OBJECT_ACTIVE);
+ 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 (unlikely(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 PFA_SPREAD_SLAB is a mempolicy is set.
+ *
+ * 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 = mempolicy_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 = read_mems_allowed_begin();
+ zonelist = node_zonelist(mempolicy_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(zone, flags) &&
+ get_node(cache, nid) &&
+ get_node(cache, nid)->free_objects) {
+ obj = ____cache_alloc_node(cache,
+ gfp_exact_node(flags), 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.
+ */
+ struct page *page;
+
+ if (local_flags & __GFP_WAIT)
+ local_irq_enable();
+ kmem_flagcheck(cache, flags);
+ page = kmem_getpages(cache, local_flags, numa_mem_id());
+ if (local_flags & __GFP_WAIT)
+ local_irq_disable();
+ if (page) {
+ /*
+ * Insert into the appropriate per node queues
+ */
+ nid = page_to_nid(page);
+ if (cache_grow(cache, flags, nid, page)) {
+ obj = ____cache_alloc_node(cache,
+ gfp_exact_node(flags), 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(!obj && read_mems_allowed_retry(cpuset_mems_cookie)))
+ 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 page *page;
+ struct kmem_cache_node *n;
+ void *obj;
+ int x;
+
+ VM_BUG_ON(nodeid < 0 || nodeid >= MAX_NUMNODES);
+ n = get_node(cachep, 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;
+ }
+
+ page = list_entry(entry, struct page, lru);
+ check_spinlock_acquired_node(cachep, nodeid);
+
+ STATS_INC_NODEALLOCS(cachep);
+ STATS_INC_ACTIVE(cachep);
+ STATS_SET_HIGH(cachep);
+
+ BUG_ON(page->active == cachep->num);
+
+ obj = slab_get_obj(cachep, page, nodeid);
+ n->free_objects--;
+ /* move slabp to correct slabp list: */
+ list_del(&page->lru);
+
+ if (page->active == cachep->num)
+ list_add(&page->lru, &n->slabs_full);
+ else
+ list_add(&page->lru, &n->slabs_partial);
+
+ spin_unlock(&n->list_lock);
+ goto done;
+
+must_grow:
+ spin_unlock(&n->list_lock);
+ x = cache_grow(cachep, gfp_exact_node(flags), 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(!get_node(cachep, 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))
+ memset(ptr, 0, cachep->object_size);
+ }
+
+ memcg_kmem_put_cache(cachep);
+ return ptr;
+}
+
+static __always_inline void *
+__do_cache_alloc(struct kmem_cache *cache, gfp_t flags)
+{
+ void *objp;
+
+ if (current->mempolicy || cpuset_do_slab_mem_spread()) {
+ 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))
+ memset(objp, 0, cachep->object_size);
+ }
+
+ memcg_kmem_put_cache(cachep);
+ return objp;
+}
+
+/*
+ * Caller needs to acquire correct kmem_cache_node's list_lock
+ * @list: List of detached free slabs should be freed by caller
+ */
+static void free_block(struct kmem_cache *cachep, void **objpp,
+ int nr_objects, int node, struct list_head *list)
+{
+ int i;
+ struct kmem_cache_node *n = get_node(cachep, node);
+
+ for (i = 0; i < nr_objects; i++) {
+ void *objp;
+ struct page *page;
+
+ clear_obj_pfmemalloc(&objpp[i]);
+ objp = objpp[i];
+
+ page = virt_to_head_page(objp);
+ list_del(&page->lru);
+ check_spinlock_acquired_node(cachep, node);
+ slab_put_obj(cachep, page, objp, node);
+ STATS_DEC_ACTIVE(cachep);
+ n->free_objects++;
+
+ /* fixup slab chains */
+ if (page->active == 0) {
+ if (n->free_objects > n->free_limit) {
+ n->free_objects -= cachep->num;
+ list_add_tail(&page->lru, list);
+ } else {
+ list_add(&page->lru, &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(&page->lru, &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();
+ LIST_HEAD(list);
+
+ batchcount = ac->batchcount;
+#if DEBUG
+ BUG_ON(!batchcount || batchcount > ac->avail);
+#endif
+ check_irq_off();
+ n = get_node(cachep, 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, &list);
+free_done:
+#if STATS
+ {
+ int i = 0;
+ struct list_head *p;
+
+ p = n->slabs_free.next;
+ while (p != &(n->slabs_free)) {
+ struct page *page;
+
+ page = list_entry(p, struct page, lru);
+ BUG_ON(page->active);
+
+ i++;
+ p = p->next;
+ }
+ STATS_SET_FREEABLE(cachep, i);
+ }
+#endif
+ spin_unlock(&n->list_lock);
+ slabs_destroy(cachep, &list);
+ 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 (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);
+}
+
+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);
+#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;
+
+ 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;
+}
+
+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);
+
+/**
+ * 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_kmem_cache_node(struct kmem_cache *cachep, gfp_t gfp)
+{
+ int node;
+ struct kmem_cache_node *n;
+ struct array_cache *new_shared;
+ struct alien_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 = get_node(cachep, node);
+ if (n) {
+ struct array_cache *shared = n->shared;
+ LIST_HEAD(list);
+
+ spin_lock_irq(&n->list_lock);
+
+ if (shared)
+ free_block(cachep, shared->entry,
+ shared->avail, node, &list);
+
+ 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);
+ slabs_destroy(cachep, &list);
+ 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_NODE +
+ ((unsigned long)cachep) % REAPTIMEOUT_NODE;
+ 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) {
+ n = get_node(cachep, node);
+ if (n) {
+ kfree(n->shared);
+ free_alien_cache(n->alien);
+ kfree(n);
+ cachep->node[node] = NULL;
+ }
+ node--;
+ }
+ }
+ return -ENOMEM;
+}
+
+/* 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 array_cache __percpu *cpu_cache, *prev;
+ int cpu;
+
+ cpu_cache = alloc_kmem_cache_cpus(cachep, limit, batchcount);
+ if (!cpu_cache)
+ return -ENOMEM;
+
+ prev = cachep->cpu_cache;
+ cachep->cpu_cache = cpu_cache;
+ kick_all_cpus_sync();
+
+ check_irq_on();
+ cachep->batchcount = batchcount;
+ cachep->limit = limit;
+ cachep->shared = shared;
+
+ if (!prev)
+ goto alloc_node;
+
+ for_each_online_cpu(cpu) {
+ LIST_HEAD(list);
+ int node;
+ struct kmem_cache_node *n;
+ struct array_cache *ac = per_cpu_ptr(prev, cpu);
+
+ node = cpu_to_mem(cpu);
+ n = get_node(cachep, node);
+ spin_lock_irq(&n->list_lock);
+ free_block(cachep, ac->entry, ac->avail, node, &list);
+ spin_unlock_irq(&n->list_lock);
+ slabs_destroy(cachep, &list);
+ }
+ free_percpu(prev);
+
+alloc_node:
+ return alloc_kmem_cache_node(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;
+
+ ret = __do_tune_cpucache(cachep, limit, batchcount, shared, gfp);
+
+ if (slab_state < FULL)
+ return ret;
+
+ if ((ret < 0) || !is_root_cache(cachep))
+ return ret;
+
+ lockdep_assert_held(&slab_mutex);
+ for_each_memcg_cache(c, cachep) {
+ /* return value determined by the root 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)
+{
+ LIST_HEAD(list);
+ 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, &list);
+ ac->avail -= tofree;
+ memmove(ac->entry, &(ac->entry[tofree]),
+ sizeof(void *) * ac->avail);
+ }
+ spin_unlock_irq(&n->list_lock);
+ slabs_destroy(cachep, &list);
+ }
+}
+
+/**
+ * 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 = get_node(searchp, 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_NODE;
+
+ 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_AC));
+}
+
+#ifdef CONFIG_SLABINFO
+void get_slabinfo(struct kmem_cache *cachep, struct slabinfo *sinfo)
+{
+ struct page *page;
+ 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_kmem_cache_node(cachep, node, n) {
+
+ check_irq_on();
+ spin_lock_irq(&n->list_lock);
+
+ list_for_each_entry(page, &n->slabs_full, lru) {
+ if (page->active != cachep->num && !error)
+ error = "slabs_full accounting error";
+ active_objs += cachep->num;
+ active_slabs++;
+ }
+ list_for_each_entry(page, &n->slabs_partial, lru) {
+ if (page->active == cachep->num && !error)
+ error = "slabs_partial accounting error";
+ if (!page->active && !error)
+ error = "slabs_partial accounting error";
+ active_objs += page->active;
+ active_slabs++;
+ }
+ list_for_each_entry(page, &n->slabs_free, lru) {
+ if (page->active && !error)
+ error = "slabs_free 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 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 page *page)
+{
+ void *p;
+ int i;
+
+ if (n[0] == n[1])
+ return;
+ for (i = 0, p = page->s_mem; i < c->num; i++, p += c->size) {
+ if (get_obj_status(page, i) != OBJECT_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 page *page;
+ 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_kmem_cache_node(cachep, node, n) {
+
+ check_irq_on();
+ spin_lock_irq(&n->list_lock);
+
+ list_for_each_entry(page, &n->slabs_full, lru)
+ handle_slab(x, cachep, page);
+ list_for_each_entry(page, &n->slabs_partial, lru)
+ handle_slab(x, cachep, page);
+ 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 = slab_start,
+ .next = slab_next,
+ .stop = slab_stop,
+ .show = leaks_show,
+};
+
+static int slabstats_open(struct inode *inode, struct file *file)
+{
+ unsigned long *n;
+
+ n = __seq_open_private(file, &slabstats_op, PAGE_SIZE);
+ if (!n)
+ return -ENOMEM;
+
+ *n = PAGE_SIZE / (2 * sizeof(unsigned long));
+
+ return 0;
+}
+
+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);
Code Review / kvmfornfv.git / blobdiff