diff options
Diffstat (limited to 'mm/slub.c')
| -rw-r--r-- | mm/slub.c | 4515 |
1 files changed, 4515 insertions, 0 deletions
diff --git a/mm/slub.c b/mm/slub.c new file mode 100644 index 0000000..a2cd47d --- /dev/null +++ b/mm/slub.c @@ -0,0 +1,4515 @@ +/* + * SLUB: A slab allocator that limits cache line use instead of queuing + * objects in per cpu and per node lists. + * + * The allocator synchronizes using per slab locks and only + * uses a centralized lock to manage a pool of partial slabs. + * + * (C) 2007 SGI, Christoph Lameter + */ + +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/bit_spinlock.h> +#include <linux/interrupt.h> +#include <linux/bitops.h> +#include <linux/slab.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/cpu.h> +#include <linux/cpuset.h> +#include <linux/mempolicy.h> +#include <linux/ctype.h> +#include <linux/debugobjects.h> +#include <linux/kallsyms.h> +#include <linux/memory.h> +#include <linux/math64.h> + +/* + * Lock order: + * 1. slab_lock(page) + * 2. slab->list_lock + * + * The slab_lock protects operations on the object of a particular + * slab and its metadata in the page struct. If the slab lock + * has been taken then no allocations nor frees can be performed + * on the objects in the slab nor can the slab be added or removed + * from the partial or full lists since this would mean modifying + * the page_struct of the slab. + * + * The list_lock protects the partial and full list on each node and + * the partial slab counter. If taken then no new slabs may be added or + * removed from the lists nor make the number of partial slabs be modified. + * (Note that the total number of slabs is an atomic value that may be + * modified without taking the list lock). + * + * The list_lock is a centralized lock and thus we avoid taking it as + * much as possible. As long as SLUB does not have to handle partial + * slabs, operations can continue without any centralized lock. F.e. + * allocating a long series of objects that fill up slabs does not require + * the list lock. + * + * The lock order is sometimes inverted when we are trying to get a slab + * off a list. We take the list_lock and then look for a page on the list + * to use. While we do that objects in the slabs may be freed. We can + * only operate on the slab if we have also taken the slab_lock. So we use + * a slab_trylock() on the slab. If trylock was successful then no frees + * can occur anymore and we can use the slab for allocations etc. If the + * slab_trylock() does not succeed then frees are in progress in the slab and + * we must stay away from it for a while since we may cause a bouncing + * cacheline if we try to acquire the lock. So go onto the next slab. + * If all pages are busy then we may allocate a new slab instead of reusing + * a partial slab. A new slab has noone operating on it and thus there is + * no danger of cacheline contention. + * + * Interrupts are disabled during allocation and deallocation in order to + * make the slab allocator safe to use in the context of an irq. In addition + * interrupts are disabled to ensure that the processor does not change + * while handling per_cpu slabs, due to kernel preemption. + * + * SLUB assigns one slab for allocation to each processor. + * Allocations only occur from these slabs called cpu slabs. + * + * Slabs with free elements are kept on a partial list and during regular + * operations no list for full slabs is used. If an object in a full slab is + * freed then the slab will show up again on the partial lists. + * We track full slabs for debugging purposes though because otherwise we + * cannot scan all objects. + * + * Slabs are freed when they become empty. Teardown and setup is + * minimal so we rely on the page allocators per cpu caches for + * fast frees and allocs. + * + * Overloading of page flags that are otherwise used for LRU management. + * + * PageActive The slab is frozen and exempt from list processing. + * This means that the slab is dedicated to a purpose + * such as satisfying allocations for a specific + * processor. Objects may be freed in the slab while + * it is frozen but slab_free will then skip the usual + * list operations. It is up to the processor holding + * the slab to integrate the slab into the slab lists + * when the slab is no longer needed. + * + * One use of this flag is to mark slabs that are + * used for allocations. Then such a slab becomes a cpu + * slab. The cpu slab may be equipped with an additional + * freelist that allows lockless access to + * free objects in addition to the regular freelist + * that requires the slab lock. + * + * PageError Slab requires special handling due to debug + * options set. This moves slab handling out of + * the fast path and disables lockless freelists. + */ + +#ifdef CONFIG_SLUB_DEBUG +#define SLABDEBUG 1 +#else +#define SLABDEBUG 0 +#endif + +/* + * Issues still to be resolved: + * + * - Support PAGE_ALLOC_DEBUG. Should be easy to do. + * + * - Variable sizing of the per node arrays + */ + +/* Enable to test recovery from slab corruption on boot */ +#undef SLUB_RESILIENCY_TEST + +/* + * Mininum number of partial slabs. These will be left on the partial + * lists even if they are empty. kmem_cache_shrink may reclaim them. + */ +#define MIN_PARTIAL 5 + +/* + * Maximum number of desirable partial slabs. + * The existence of more partial slabs makes kmem_cache_shrink + * sort the partial list by the number of objects in the. + */ +#define MAX_PARTIAL 10 + +#define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \ + SLAB_POISON | SLAB_STORE_USER) + +/* + * Set of flags that will prevent slab merging + */ +#define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ + SLAB_TRACE | SLAB_DESTROY_BY_RCU) + +#define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \ + SLAB_CACHE_DMA) + +#ifndef ARCH_KMALLOC_MINALIGN +#define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) +#endif + +#ifndef ARCH_SLAB_MINALIGN +#define ARCH_SLAB_MINALIGN __alignof__(unsigned long long) +#endif + +/* Internal SLUB flags */ +#define __OBJECT_POISON 0x80000000 /* Poison object */ +#define __SYSFS_ADD_DEFERRED 0x40000000 /* Not yet visible via sysfs */ + +static int kmem_size = sizeof(struct kmem_cache); + +#ifdef CONFIG_SMP +static struct notifier_block slab_notifier; +#endif + +static enum { + DOWN, /* No slab functionality available */ + PARTIAL, /* kmem_cache_open() works but kmalloc does not */ + UP, /* Everything works but does not show up in sysfs */ + SYSFS /* Sysfs up */ +} slab_state = DOWN; + +/* A list of all slab caches on the system */ +static DECLARE_RWSEM(slub_lock); +static LIST_HEAD(slab_caches); + +/* + * Tracking user of a slab. + */ +struct track { + void *addr; /* Called from address */ + int cpu; /* Was running on cpu */ + int pid; /* Pid context */ + unsigned long when; /* When did the operation occur */ +}; + +enum track_item { TRACK_ALLOC, TRACK_FREE }; + +#ifdef CONFIG_SLUB_DEBUG +static int sysfs_slab_add(struct kmem_cache *); +static int sysfs_slab_alias(struct kmem_cache *, const char *); +static void sysfs_slab_remove(struct kmem_cache *); + +#else +static inline int sysfs_slab_add(struct kmem_cache *s) { return 0; } +static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p) + { return 0; } +static inline void sysfs_slab_remove(struct kmem_cache *s) +{ + kfree(s); +} + +#endif + +static inline void stat(struct kmem_cache_cpu *c, enum stat_item si) +{ +#ifdef CONFIG_SLUB_STATS + c->stat[si]++; +#endif +} + +/******************************************************************** + * Core slab cache functions + *******************************************************************/ + +int slab_is_available(void) +{ + return slab_state >= UP; +} + +static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node) +{ +#ifdef CONFIG_NUMA + return s->node[node]; +#else + return &s->local_node; +#endif +} + +static inline struct kmem_cache_cpu *get_cpu_slab(struct kmem_cache *s, int cpu) +{ +#ifdef CONFIG_SMP + return s->cpu_slab[cpu]; +#else + return &s->cpu_slab; +#endif +} + +/* Verify that a pointer has an address that is valid within a slab page */ +static inline int check_valid_pointer(struct kmem_cache *s, + struct page *page, const void *object) +{ + void *base; + + if (!object) + return 1; + + base = page_address(page); + if (object < base || object >= base + page->objects * s->size || + (object - base) % s->size) { + return 0; + } + + return 1; +} + +/* + * Slow version of get and set free pointer. + * + * This version requires touching the cache lines of kmem_cache which + * we avoid to do in the fast alloc free paths. There we obtain the offset + * from the page struct. + */ +static inline void *get_freepointer(struct kmem_cache *s, void *object) +{ + return *(void **)(object + s->offset); +} + +static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp) +{ + *(void **)(object + s->offset) = fp; +} + +/* Loop over all objects in a slab */ +#define for_each_object(__p, __s, __addr, __objects) \ + for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\ + __p += (__s)->size) + +/* Scan freelist */ +#define for_each_free_object(__p, __s, __free) \ + for (__p = (__free); __p; __p = get_freepointer((__s), __p)) + +/* Determine object index from a given position */ +static inline int slab_index(void *p, struct kmem_cache *s, void *addr) +{ + return (p - addr) / s->size; +} + +static inline struct kmem_cache_order_objects oo_make(int order, + unsigned long size) +{ + struct kmem_cache_order_objects x = { + (order << 16) + (PAGE_SIZE << order) / size + }; + + return x; +} + +static inline int oo_order(struct kmem_cache_order_objects x) +{ + return x.x >> 16; +} + +static inline int oo_objects(struct kmem_cache_order_objects x) +{ + return x.x & ((1 << 16) - 1); +} + +#ifdef CONFIG_SLUB_DEBUG +/* + * Debug settings: + */ +#ifdef CONFIG_SLUB_DEBUG_ON +static int slub_debug = DEBUG_DEFAULT_FLAGS; +#else +static int slub_debug; +#endif + +static char *slub_debug_slabs; + +/* + * Object debugging + */ +static void print_section(char *text, u8 *addr, unsigned int length) +{ + int i, offset; + int newline = 1; + char ascii[17]; + + ascii[16] = 0; + + for (i = 0; i < length; i++) { + if (newline) { + printk(KERN_ERR "%8s 0x%p: ", text, addr + i); + newline = 0; + } + printk(KERN_CONT " %02x", addr[i]); + offset = i % 16; + ascii[offset] = isgraph(addr[i]) ? addr[i] : '.'; + if (offset == 15) { + printk(KERN_CONT " %s\n", ascii); + newline = 1; + } + } + if (!newline) { + i %= 16; + while (i < 16) { + printk(KERN_CONT " "); + ascii[i] = ' '; + i++; + } + printk(KERN_CONT " %s\n", ascii); + } +} + +static struct track *get_track(struct kmem_cache *s, void *object, + enum track_item alloc) +{ + struct track *p; + + if (s->offset) + p = object + s->offset + sizeof(void *); + else + p = object + s->inuse; + + return p + alloc; +} + +static void set_track(struct kmem_cache *s, void *object, + enum track_item alloc, void *addr) +{ + struct track *p; + + if (s->offset) + p = object + s->offset + sizeof(void *); + else + p = object + s->inuse; + + p += alloc; + if (addr) { + p->addr = addr; + p->cpu = smp_processor_id(); + p->pid = current->pid; + p->when = jiffies; + } else + memset(p, 0, sizeof(struct track)); +} + +static void init_tracking(struct kmem_cache *s, void *object) +{ + if (!(s->flags & SLAB_STORE_USER)) + return; + + set_track(s, object, TRACK_FREE, NULL); + set_track(s, object, TRACK_ALLOC, NULL); +} + +static void print_track(const char *s, struct track *t) +{ + if (!t->addr) + return; + + printk(KERN_ERR "INFO: %s in %pS age=%lu cpu=%u pid=%d\n", + s, t->addr, jiffies - t->when, t->cpu, t->pid); +} + +static void print_tracking(struct kmem_cache *s, void *object) +{ + if (!(s->flags & SLAB_STORE_USER)) + return; + + print_track("Allocated", get_track(s, object, TRACK_ALLOC)); + print_track("Freed", get_track(s, object, TRACK_FREE)); +} + +static void print_page_info(struct page *page) +{ + printk(KERN_ERR "INFO: Slab 0x%p objects=%u used=%u fp=0x%p flags=0x%04lx\n", + page, page->objects, page->inuse, page->freelist, page->flags); + +} + +static void slab_bug(struct kmem_cache *s, char *fmt, ...) +{ + va_list args; + char buf[100]; + + va_start(args, fmt); + vsnprintf(buf, sizeof(buf), fmt, args); + va_end(args); + printk(KERN_ERR "========================================" + "=====================================\n"); + printk(KERN_ERR "BUG %s: %s\n", s->name, buf); + printk(KERN_ERR "----------------------------------------" + "-------------------------------------\n\n"); +} + +static void slab_fix(struct kmem_cache *s, char *fmt, ...) +{ + va_list args; + char buf[100]; + + va_start(args, fmt); + vsnprintf(buf, sizeof(buf), fmt, args); + va_end(args); + printk(KERN_ERR "FIX %s: %s\n", s->name, buf); +} + +static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p) +{ + unsigned int off; /* Offset of last byte */ + u8 *addr = page_address(page); + + print_tracking(s, p); + + print_page_info(page); + + printk(KERN_ERR "INFO: Object 0x%p @offset=%tu fp=0x%p\n\n", + p, p - addr, get_freepointer(s, p)); + + if (p > addr + 16) + print_section("Bytes b4", p - 16, 16); + + print_section("Object", p, min_t(unsigned long, s->objsize, PAGE_SIZE)); + + if (s->flags & SLAB_RED_ZONE) + print_section("Redzone", p + s->objsize, + s->inuse - s->objsize); + + if (s->offset) + off = s->offset + sizeof(void *); + else + off = s->inuse; + + if (s->flags & SLAB_STORE_USER) + off += 2 * sizeof(struct track); + + if (off != s->size) + /* Beginning of the filler is the free pointer */ + print_section("Padding", p + off, s->size - off); + + dump_stack(); +} + +static void object_err(struct kmem_cache *s, struct page *page, + u8 *object, char *reason) +{ + slab_bug(s, "%s", reason); + print_trailer(s, page, object); +} + +static void slab_err(struct kmem_cache *s, struct page *page, char *fmt, ...) +{ + va_list args; + char buf[100]; + + va_start(args, fmt); + vsnprintf(buf, sizeof(buf), fmt, args); + va_end(args); + slab_bug(s, "%s", buf); + print_page_info(page); + dump_stack(); +} + +static void init_object(struct kmem_cache *s, void *object, int active) +{ + u8 *p = object; + + if (s->flags & __OBJECT_POISON) { + memset(p, POISON_FREE, s->objsize - 1); + p[s->objsize - 1] = POISON_END; + } + + if (s->flags & SLAB_RED_ZONE) + memset(p + s->objsize, + active ? SLUB_RED_ACTIVE : SLUB_RED_INACTIVE, + s->inuse - s->objsize); +} + +static u8 *check_bytes(u8 *start, unsigned int value, unsigned int bytes) +{ + while (bytes) { + if (*start != (u8)value) + return start; + start++; + bytes--; + } + return NULL; +} + +static void restore_bytes(struct kmem_cache *s, char *message, u8 data, + void *from, void *to) +{ + slab_fix(s, "Restoring 0x%p-0x%p=0x%x\n", from, to - 1, data); + memset(from, data, to - from); +} + +static int check_bytes_and_report(struct kmem_cache *s, struct page *page, + u8 *object, char *what, + u8 *start, unsigned int value, unsigned int bytes) +{ + u8 *fault; + u8 *end; + + fault = check_bytes(start, value, bytes); + if (!fault) + return 1; + + end = start + bytes; + while (end > fault && end[-1] == value) + end--; + + slab_bug(s, "%s overwritten", what); + printk(KERN_ERR "INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n", + fault, end - 1, fault[0], value); + print_trailer(s, page, object); + + restore_bytes(s, what, value, fault, end); + return 0; +} + +/* + * Object layout: + * + * object address + * Bytes of the object to be managed. + * If the freepointer may overlay the object then the free + * pointer is the first word of the object. + * + * Poisoning uses 0x6b (POISON_FREE) and the last byte is + * 0xa5 (POISON_END) + * + * object + s->objsize + * Padding to reach word boundary. This is also used for Redzoning. + * Padding is extended by another word if Redzoning is enabled and + * objsize == inuse. + * + * We fill with 0xbb (RED_INACTIVE) for inactive objects and with + * 0xcc (RED_ACTIVE) for objects in use. + * + * object + s->inuse + * Meta data starts here. + * + * A. Free pointer (if we cannot overwrite object on free) + * B. Tracking data for SLAB_STORE_USER + * C. Padding to reach required alignment boundary or at mininum + * one word if debugging is on to be able to detect writes + * before the word boundary. + * + * Padding is done using 0x5a (POISON_INUSE) + * + * object + s->size + * Nothing is used beyond s->size. + * + * If slabcaches are merged then the objsize and inuse boundaries are mostly + * ignored. And therefore no slab options that rely on these boundaries + * may be used with merged slabcaches. + */ + +static int check_pad_bytes(struct kmem_cache *s, struct page *page, u8 *p) +{ + unsigned long off = s->inuse; /* The end of info */ + + if (s->offset) + /* Freepointer is placed after the object. */ + off += sizeof(void *); + + if (s->flags & SLAB_STORE_USER) + /* We also have user information there */ + off += 2 * sizeof(struct track); + + if (s->size == off) + return 1; + + return check_bytes_and_report(s, page, p, "Object padding", + p + off, POISON_INUSE, s->size - off); +} + +/* Check the pad bytes at the end of a slab page */ +static int slab_pad_check(struct kmem_cache *s, struct page *page) +{ + u8 *start; + u8 *fault; + u8 *end; + int length; + int remainder; + + if (!(s->flags & SLAB_POISON)) + return 1; + + start = page_address(page); + length = (PAGE_SIZE << compound_order(page)); + end = start + length; + remainder = length % s->size; + if (!remainder) + return 1; + + fault = check_bytes(end - remainder, POISON_INUSE, remainder); + if (!fault) + return 1; + while (end > fault && end[-1] == POISON_INUSE) + end--; + + slab_err(s, page, "Padding overwritten. 0x%p-0x%p", fault, end - 1); + print_section("Padding", end - remainder, remainder); + + restore_bytes(s, "slab padding", POISON_INUSE, start, end); + return 0; +} + +static int check_object(struct kmem_cache *s, struct page *page, + void *object, int active) +{ + u8 *p = object; + u8 *endobject = object + s->objsize; + + if (s->flags & SLAB_RED_ZONE) { + unsigned int red = + active ? SLUB_RED_ACTIVE : SLUB_RED_INACTIVE; + + if (!check_bytes_and_report(s, page, object, "Redzone", + endobject, red, s->inuse - s->objsize)) + return 0; + } else { + if ((s->flags & SLAB_POISON) && s->objsize < s->inuse) { + check_bytes_and_report(s, page, p, "Alignment padding", + endobject, POISON_INUSE, s->inuse - s->objsize); + } + } + + if (s->flags & SLAB_POISON) { + if (!active && (s->flags & __OBJECT_POISON) && + (!check_bytes_and_report(s, page, p, "Poison", p, + POISON_FREE, s->objsize - 1) || + !check_bytes_and_report(s, page, p, "Poison", + p + s->objsize - 1, POISON_END, 1))) + return 0; + /* + * check_pad_bytes cleans up on its own. + */ + check_pad_bytes(s, page, p); + } + + if (!s->offset && active) + /* + * Object and freepointer overlap. Cannot check + * freepointer while object is allocated. + */ + return 1; + + /* Check free pointer validity */ + if (!check_valid_pointer(s, page, get_freepointer(s, p))) { + object_err(s, page, p, "Freepointer corrupt"); + /* + * No choice but to zap it and thus loose the remainder + * of the free objects in this slab. May cause + * another error because the object count is now wrong. + */ + set_freepointer(s, p, NULL); + return 0; + } + return 1; +} + +static int check_slab(struct kmem_cache *s, struct page *page) +{ + int maxobj; + + VM_BUG_ON(!irqs_disabled()); + + if (!PageSlab(page)) { + slab_err(s, page, "Not a valid slab page"); + return 0; + } + + maxobj = (PAGE_SIZE << compound_order(page)) / s->size; + if (page->objects > maxobj) { + slab_err(s, page, "objects %u > max %u", + s->name, page->objects, maxobj); + return 0; + } + if (page->inuse > page->objects) { + slab_err(s, page, "inuse %u > max %u", + s->name, page->inuse, page->objects); + return 0; + } + /* Slab_pad_check fixes things up after itself */ + slab_pad_check(s, page); + return 1; +} + +/* + * Determine if a certain object on a page is on the freelist. Must hold the + * slab lock to guarantee that the chains are in a consistent state. + */ +static int on_freelist(struct kmem_cache *s, struct page *page, void *search) +{ + int nr = 0; + void *fp = page->freelist; + void *object = NULL; + unsigned long max_objects; + + while (fp && nr <= page->objects) { + if (fp == search) + return 1; + if (!check_valid_pointer(s, page, fp)) { + if (object) { + object_err(s, page, object, + "Freechain corrupt"); + set_freepointer(s, object, NULL); + break; + } else { + slab_err(s, page, "Freepointer corrupt"); + page->freelist = NULL; + page->inuse = page->objects; + slab_fix(s, "Freelist cleared"); + return 0; + } + break; + } + object = fp; + fp = get_freepointer(s, object); + nr++; + } + + max_objects = (PAGE_SIZE << compound_order(page)) / s->size; + if (max_objects > 65535) + max_objects = 65535; + + if (page->objects != max_objects) { + slab_err(s, page, "Wrong number of objects. Found %d but " + "should be %d", page->objects, max_objects); + page->objects = max_objects; + slab_fix(s, "Number of objects adjusted."); + } + if (page->inuse != page->objects - nr) { + slab_err(s, page, "Wrong object count. Counter is %d but " + "counted were %d", page->inuse, page->objects - nr); + page->inuse = page->objects - nr; + slab_fix(s, "Object count adjusted."); + } + return search == NULL; +} + +static void trace(struct kmem_cache *s, struct page *page, void *object, + int alloc) +{ + if (s->flags & SLAB_TRACE) { + printk(KERN_INFO "TRACE %s %s 0x%p inuse=%d fp=0x%p\n", + s->name, + alloc ? "alloc" : "free", + object, page->inuse, + page->freelist); + + if (!alloc) + print_section("Object", (void *)object, s->objsize); + + dump_stack(); + } +} + +/* + * Tracking of fully allocated slabs for debugging purposes. + */ +static void add_full(struct kmem_cache_node *n, struct page *page) +{ + spin_lock(&n->list_lock); + list_add(&page->lru, &n->full); + spin_unlock(&n->list_lock); +} + +static void remove_full(struct kmem_cache *s, struct page *page) +{ + struct kmem_cache_node *n; + + if (!(s->flags & SLAB_STORE_USER)) + return; + + n = get_node(s, page_to_nid(page)); + + spin_lock(&n->list_lock); + list_del(&page->lru); + spin_unlock(&n->list_lock); +} + +/* Tracking of the number of slabs for debugging purposes */ +static inline unsigned long slabs_node(struct kmem_cache *s, int node) +{ + struct kmem_cache_node *n = get_node(s, node); + + return atomic_long_read(&n->nr_slabs); +} + +static inline void inc_slabs_node(struct kmem_cache *s, int node, int objects) +{ + struct kmem_cache_node *n = get_node(s, node); + + /* + * May be called early in order to allocate a slab for the + * kmem_cache_node structure. Solve the chicken-egg + * dilemma by deferring the increment of the count during + * bootstrap (see early_kmem_cache_node_alloc). + */ + if (!NUMA_BUILD || n) { + atomic_long_inc(&n->nr_slabs); + atomic_long_add(objects, &n->total_objects); + } +} +static inline void dec_slabs_node(struct kmem_cache *s, int node, int objects) +{ + struct kmem_cache_node *n = get_node(s, node); + + atomic_long_dec(&n->nr_slabs); + atomic_long_sub(objects, &n->total_objects); +} + +/* Object debug checks for alloc/free paths */ +static void setup_object_debug(struct kmem_cache *s, struct page *page, + void *object) +{ + if (!(s->flags & (SLAB_STORE_USER|SLAB_RED_ZONE|__OBJECT_POISON))) + return; + + init_object(s, object, 0); + init_tracking(s, object); +} + +static int alloc_debug_processing(struct kmem_cache *s, struct page *page, + void *object, void *addr) +{ + if (!check_slab(s, page)) + goto bad; + + if (!on_freelist(s, page, object)) { + object_err(s, page, object, "Object already allocated"); + goto bad; + } + + if (!check_valid_pointer(s, page, object)) { + object_err(s, page, object, "Freelist Pointer check fails"); + goto bad; + } + + if (!check_object(s, page, object, 0)) + goto bad; + + /* Success perform special debug activities for allocs */ + if (s->flags & SLAB_STORE_USER) + set_track(s, object, TRACK_ALLOC, addr); + trace(s, page, object, 1); + init_object(s, object, 1); + return 1; + +bad: + if (PageSlab(page)) { + /* + * If this is a slab page then lets do the best we can + * to avoid issues in the future. Marking all objects + * as used avoids touching the remaining objects. + */ + slab_fix(s, "Marking all objects used"); + page->inuse = page->objects; + page->freelist = NULL; + } + return 0; +} + +static int free_debug_processing(struct kmem_cache *s, struct page *page, + void *object, void *addr) +{ + if (!check_slab(s, page)) + goto fail; + + if (!check_valid_pointer(s, page, object)) { + slab_err(s, page, "Invalid object pointer 0x%p", object); + goto fail; + } + + if (on_freelist(s, page, object)) { + object_err(s, page, object, "Object already free"); + goto fail; + } + + if (!check_object(s, page, object, 1)) + return 0; + + if (unlikely(s != page->slab)) { + if (!PageSlab(page)) { + slab_err(s, page, "Attempt to free object(0x%p) " + "outside of slab", object); + } else if (!page->slab) { + printk(KERN_ERR + "SLUB <none>: no slab for object 0x%p.\n", + object); + dump_stack(); + } else + object_err(s, page, object, + "page slab pointer corrupt."); + goto fail; + } + + /* Special debug activities for freeing objects */ + if (!PageSlubFrozen(page) && !page->freelist) + remove_full(s, page); + if (s->flags & SLAB_STORE_USER) + set_track(s, object, TRACK_FREE, addr); + trace(s, page, object, 0); + init_object(s, object, 0); + return 1; + +fail: + slab_fix(s, "Object at 0x%p not freed", object); + return 0; +} + +static int __init setup_slub_debug(char *str) +{ + slub_debug = DEBUG_DEFAULT_FLAGS; + if (*str++ != '=' || !*str) + /* + * No options specified. Switch on full debugging. + */ + goto out; + + if (*str == ',') + /* + * No options but restriction on slabs. This means full + * debugging for slabs matching a pattern. + */ + goto check_slabs; + + slub_debug = 0; + if (*str == '-') + /* + * Switch off all debugging measures. + */ + goto out; + + /* + * Determine which debug features should be switched on + */ + for (; *str && *str != ','; str++) { + switch (tolower(*str)) { + case 'f': + slub_debug |= SLAB_DEBUG_FREE; + break; + case 'z': + slub_debug |= SLAB_RED_ZONE; + break; + case 'p': + slub_debug |= SLAB_POISON; + break; + case 'u': + slub_debug |= SLAB_STORE_USER; + break; + case 't': + slub_debug |= SLAB_TRACE; + break; + default: + printk(KERN_ERR "slub_debug option '%c' " + "unknown. skipped\n", *str); + } + } + +check_slabs: + if (*str == ',') + slub_debug_slabs = str + 1; +out: + return 1; +} + +__setup("slub_debug", setup_slub_debug); + +static unsigned long kmem_cache_flags(unsigned long objsize, + unsigned long flags, const char *name, + void (*ctor)(void *)) +{ + /* + * Enable debugging if selected on the kernel commandline. + */ + if (slub_debug && (!slub_debug_slabs || + strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs)) == 0)) + flags |= slub_debug; + + return flags; +} +#else +static inline void setup_object_debug(struct kmem_cache *s, + struct page *page, void *object) {} + +static inline int alloc_debug_processing(struct kmem_cache *s, + struct page *page, void *object, void *addr) { return 0; } + +static inline int free_debug_processing(struct kmem_cache *s, + struct page *page, void *object, void *addr) { return 0; } + +static inline int slab_pad_check(struct kmem_cache *s, struct page *page) + { return 1; } +static inline int check_object(struct kmem_cache *s, struct page *page, + void *object, int active) { return 1; } +static inline void add_full(struct kmem_cache_node *n, struct page *page) {} +static inline unsigned long kmem_cache_flags(unsigned long objsize, + unsigned long flags, const char *name, + void (*ctor)(void *)) +{ + return flags; +} +#define slub_debug 0 + +static inline unsigned long slabs_node(struct kmem_cache *s, int node) + { return 0; } +static inline void inc_slabs_node(struct kmem_cache *s, int node, + int objects) {} +static inline void dec_slabs_node(struct kmem_cache *s, int node, + int objects) {} +#endif + +/* + * Slab allocation and freeing + */ +static inline struct page *alloc_slab_page(gfp_t flags, int node, + struct kmem_cache_order_objects oo) +{ + int order = oo_order(oo); + + if (node == -1) + return alloc_pages(flags, order); + else + return alloc_pages_node(node, flags, order); +} + +static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) +{ + struct page *page; + struct kmem_cache_order_objects oo = s->oo; + + flags |= s->allocflags; + + page = alloc_slab_page(flags | __GFP_NOWARN | __GFP_NORETRY, node, + oo); + if (unlikely(!page)) { + oo = s->min; + /* + * Allocation may have failed due to fragmentation. + * Try a lower order alloc if possible + */ + page = alloc_slab_page(flags, node, oo); + if (!page) + return NULL; + + stat(get_cpu_slab(s, raw_smp_processor_id()), ORDER_FALLBACK); + } + page->objects = oo_objects(oo); + mod_zone_page_state(page_zone(page), + (s->flags & SLAB_RECLAIM_ACCOUNT) ? + NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE, + 1 << oo_order(oo)); + + return page; +} + +static void setup_object(struct kmem_cache *s, struct page *page, + void *object) +{ + setup_object_debug(s, page, object); + if (unlikely(s->ctor)) + s->ctor(object); +} + +static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node) +{ + struct page *page; + void *start; + void *last; + void *p; + + BUG_ON(flags & GFP_SLAB_BUG_MASK); + + page = allocate_slab(s, + flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node); + if (!page) + goto out; + + inc_slabs_node(s, page_to_nid(page), page->objects); + page->slab = s; + page->flags |= 1 << PG_slab; + if (s->flags & (SLAB_DEBUG_FREE | SLAB_RED_ZONE | SLAB_POISON | + SLAB_STORE_USER | SLAB_TRACE)) + __SetPageSlubDebug(page); + + start = page_address(page); + + if (unlikely(s->flags & SLAB_POISON)) + memset(start, POISON_INUSE, PAGE_SIZE << compound_order(page)); + + last = start; + for_each_object(p, s, start, page->objects) { + setup_object(s, page, last); + set_freepointer(s, last, p); + last = p; + } + setup_object(s, page, last); + set_freepointer(s, last, NULL); + + page->freelist = start; + page->inuse = 0; +out: + return page; +} + +static void __free_slab(struct kmem_cache *s, struct page *page) +{ + int order = compound_order(page); + int pages = 1 << order; + + if (unlikely(SLABDEBUG && PageSlubDebug(page))) { + void *p; + + slab_pad_check(s, page); + for_each_object(p, s, page_address(page), + page->objects) + check_object(s, page, p, 0); + __ClearPageSlubDebug(page); + } + + mod_zone_page_state(page_zone(page), + (s->flags & SLAB_RECLAIM_ACCOUNT) ? + NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE, + -pages); + + __ClearPageSlab(page); + reset_page_mapcount(page); + __free_pages(page, order); +} + +static void rcu_free_slab(struct rcu_head *h) +{ + struct page *page; + + page = container_of((struct list_head *)h, struct page, lru); + __free_slab(page->slab, page); +} + +static void free_slab(struct kmem_cache *s, struct page *page) +{ + if (unlikely(s->flags & SLAB_DESTROY_BY_RCU)) { + /* + * RCU free overloads the RCU head over the LRU + */ + struct rcu_head *head = (void *)&page->lru; + + call_rcu(head, rcu_free_slab); + } else + __free_slab(s, page); +} + +static void discard_slab(struct kmem_cache *s, struct page *page) +{ + dec_slabs_node(s, page_to_nid(page), page->objects); + free_slab(s, page); +} + +/* + * Per slab locking using the pagelock + */ +static __always_inline void slab_lock(struct page *page) +{ + bit_spin_lock(PG_locked, &page->flags); +} + +static __always_inline void slab_unlock(struct page *page) +{ + __bit_spin_unlock(PG_locked, &page->flags); +} + +static __always_inline int slab_trylock(struct page *page) +{ + int rc = 1; + + rc = bit_spin_trylock(PG_locked, &page->flags); + return rc; +} + +/* + * Management of partially allocated slabs + */ +static void add_partial(struct kmem_cache_node *n, + struct page *page, int tail) +{ + spin_lock(&n->list_lock); + n->nr_partial++; + if (tail) + list_add_tail(&page->lru, &n->partial); + else + list_add(&page->lru, &n->partial); + spin_unlock(&n->list_lock); +} + +static void remove_partial(struct kmem_cache *s, struct page *page) +{ + struct kmem_cache_node *n = get_node(s, page_to_nid(page)); + + spin_lock(&n->list_lock); + list_del(&page->lru); + n->nr_partial--; + spin_unlock(&n->list_lock); +} + +/* + * Lock slab and remove from the partial list. + * + * Must hold list_lock. + */ +static inline int lock_and_freeze_slab(struct kmem_cache_node *n, + struct page *page) +{ + if (slab_trylock(page)) { + list_del(&page->lru); + n->nr_partial--; + __SetPageSlubFrozen(page); + return 1; + } + return 0; +} + +/* + * Try to allocate a partial slab from a specific node. + */ +static struct page *get_partial_node(struct kmem_cache_node *n) +{ + struct page *page; + + /* + * Racy check. If we mistakenly see no partial slabs then we + * just allocate an empty slab. If we mistakenly try to get a + * partial slab and there is none available then get_partials() + * will return NULL. + */ + if (!n || !n->nr_partial) + return NULL; + + spin_lock(&n->list_lock); + list_for_each_entry(page, &n->partial, lru) + if (lock_and_freeze_slab(n, page)) + goto out; + page = NULL; +out: + spin_unlock(&n->list_lock); + return page; +} + +/* + * Get a page from somewhere. Search in increasing NUMA distances. + */ +static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags) +{ +#ifdef CONFIG_NUMA + struct zonelist *zonelist; + struct zoneref *z; + struct zone *zone; + enum zone_type high_zoneidx = gfp_zone(flags); + struct page *page; + + /* + * The defrag ratio allows a configuration of the tradeoffs between + * inter node defragmentation and node local allocations. A lower + * defrag_ratio increases the tendency to do local allocations + * instead of attempting to obtain partial slabs from other nodes. + * + * If the defrag_ratio is set to 0 then kmalloc() always + * returns node local objects. If the ratio is higher then kmalloc() + * may return off node objects because partial slabs are obtained + * from other nodes and filled up. + * + * If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes + * defrag_ratio = 1000) then every (well almost) allocation will + * first attempt to defrag slab caches on other nodes. This means + * scanning over all nodes to look for partial slabs which may be + * expensive if we do it every time we are trying to find a slab + * with available objects. + */ + if (!s->remote_node_defrag_ratio || + get_cycles() % 1024 > s->remote_node_defrag_ratio) + return NULL; + + zonelist = node_zonelist(slab_node(current->mempolicy), flags); + for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { + struct kmem_cache_node *n; + + n = get_node(s, zone_to_nid(zone)); + + if (n && cpuset_zone_allowed_hardwall(zone, flags) && + n->nr_partial > n->min_partial) { + page = get_partial_node(n); + if (page) + return page; + } + } +#endif + return NULL; +} + +/* + * Get a partial page, lock it and return it. + */ +static struct page *get_partial(struct kmem_cache *s, gfp_t flags, int node) +{ + struct page *page; + int searchnode = (node == -1) ? numa_node_id() : node; + + page = get_partial_node(get_node(s, searchnode)); + if (page || (flags & __GFP_THISNODE)) + return page; + + return get_any_partial(s, flags); +} + +/* + * Move a page back to the lists. + * + * Must be called with the slab lock held. + * + * On exit the slab lock will have been dropped. + */ +static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail) +{ + struct kmem_cache_node *n = get_node(s, page_to_nid(page)); + struct kmem_cache_cpu *c = get_cpu_slab(s, smp_processor_id()); + + __ClearPageSlubFrozen(page); + if (page->inuse) { + + if (page->freelist) { + add_partial(n, page, tail); + stat(c, tail ? DEACTIVATE_TO_TAIL : DEACTIVATE_TO_HEAD); + } else { + stat(c, DEACTIVATE_FULL); + if (SLABDEBUG && PageSlubDebug(page) && + (s->flags & SLAB_STORE_USER)) + add_full(n, page); + } + slab_unlock(page); + } else { + stat(c, DEACTIVATE_EMPTY); + if (n->nr_partial < n->min_partial) { + /* + * Adding an empty slab to the partial slabs in order + * to avoid page allocator overhead. This slab needs + * to come after the other slabs with objects in + * so that the others get filled first. That way the + * size of the partial list stays small. + * + * kmem_cache_shrink can reclaim any empty slabs from + * the partial list. + */ + add_partial(n, page, 1); + slab_unlock(page); + } else { + slab_unlock(page); + stat(get_cpu_slab(s, raw_smp_processor_id()), FREE_SLAB); + discard_slab(s, page); + } + } +} + +/* + * Remove the cpu slab + */ +static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c) +{ + struct page *page = c->page; + int tail = 1; + + if (page->freelist) + stat(c, DEACTIVATE_REMOTE_FREES); + /* + * Merge cpu freelist into slab freelist. Typically we get here + * because both freelists are empty. So this is unlikely + * to occur. + */ + while (unlikely(c->freelist)) { + void **object; + + tail = 0; /* Hot objects. Put the slab first */ + + /* Retrieve object from cpu_freelist */ + object = c->freelist; + c->freelist = c->freelist[c->offset]; + + /* And put onto the regular freelist */ + object[c->offset] = page->freelist; + page->freelist = object; + page->inuse--; + } + c->page = NULL; + unfreeze_slab(s, page, tail); +} + +static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c) +{ + stat(c, CPUSLAB_FLUSH); + slab_lock(c->page); + deactivate_slab(s, c); +} + +/* + * Flush cpu slab. + * + * Called from IPI handler with interrupts disabled. + */ +static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu) +{ + struct kmem_cache_cpu *c = get_cpu_slab(s, cpu); + + if (likely(c && c->page)) + flush_slab(s, c); +} + +static void flush_cpu_slab(void *d) +{ + struct kmem_cache *s = d; + + __flush_cpu_slab(s, smp_processor_id()); +} + +static void flush_all(struct kmem_cache *s) +{ + on_each_cpu(flush_cpu_slab, s, 1); +} + +/* + * Check if the objects in a per cpu structure fit numa + * locality expectations. + */ +static inline int node_match(struct kmem_cache_cpu *c, int node) +{ +#ifdef CONFIG_NUMA + if (node != -1 && c->node != node) + return 0; +#endif + return 1; +} + +/* + * Slow path. The lockless freelist is empty or we need to perform + * debugging duties. + * + * Interrupts are disabled. + * + * Processing is still very fast if new objects have been freed to the + * regular freelist. In that case we simply take over the regular freelist + * as the lockless freelist and zap the regular freelist. + * + * If that is not working then we fall back to the partial lists. We take the + * first element of the freelist as the object to allocate now and move the + * rest of the freelist to the lockless freelist. + * + * And if we were unable to get a new slab from the partial slab lists then + * we need to allocate a new slab. This is the slowest path since it involves + * a call to the page allocator and the setup of a new slab. + */ +static void *__slab_alloc(struct kmem_cache *s, + gfp_t gfpflags, int node, void *addr, struct kmem_cache_cpu *c) +{ + void **object; + struct page *new; + + /* We handle __GFP_ZERO in the caller */ + gfpflags &= ~__GFP_ZERO; + + if (!c->page) + goto new_slab; + + slab_lock(c->page); + if (unlikely(!node_match(c, node))) + goto another_slab; + + stat(c, ALLOC_REFILL); + +load_freelist: + object = c->page->freelist; + if (unlikely(!object)) + goto another_slab; + if (unlikely(SLABDEBUG && PageSlubDebug(c->page))) + goto debug; + + c->freelist = object[c->offset]; + c->page->inuse = c->page->objects; + c->page->freelist = NULL; + c->node = page_to_nid(c->page); +unlock_out: + slab_unlock(c->page); + stat(c, ALLOC_SLOWPATH); + return object; + +another_slab: + deactivate_slab(s, c); + +new_slab: + new = get_partial(s, gfpflags, node); + if (new) { + c->page = new; + stat(c, ALLOC_FROM_PARTIAL); + goto load_freelist; + } + + if (gfpflags & __GFP_WAIT) + local_irq_enable(); + + new = new_slab(s, gfpflags, node); + + if (gfpflags & __GFP_WAIT) + local_irq_disable(); + + if (new) { + c = get_cpu_slab(s, smp_processor_id()); + stat(c, ALLOC_SLAB); + if (c->page) + flush_slab(s, c); + slab_lock(new); + __SetPageSlubFrozen(new); + c->page = new; + goto load_freelist; + } + return NULL; +debug: + if (!alloc_debug_processing(s, c->page, object, addr)) + goto another_slab; + + c->page->inuse++; + c->page->freelist = object[c->offset]; + c->node = -1; + goto unlock_out; +} + +/* + * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc) + * have the fastpath folded into their functions. So no function call + * overhead for requests that can be satisfied on the fastpath. + * + * The fastpath works by first checking if the lockless freelist can be used. + * If not then __slab_alloc is called for slow processing. + * + * Otherwise we can simply pick the next object from the lockless free list. + */ +static __always_inline void *slab_alloc(struct kmem_cache *s, + gfp_t gfpflags, int node, void *addr) +{ + void **object; + struct kmem_cache_cpu *c; + unsigned long flags; + unsigned int objsize; + + local_irq_save(flags); + c = get_cpu_slab(s, smp_processor_id()); + objsize = c->objsize; + if (unlikely(!c->freelist || !node_match(c, node))) + + object = __slab_alloc(s, gfpflags, node, addr, c); + + else { + object = c->freelist; + c->freelist = object[c->offset]; + stat(c, ALLOC_FASTPATH); + } + local_irq_restore(flags); + + if (unlikely((gfpflags & __GFP_ZERO) && object)) + memset(object, 0, objsize); + + return object; +} + +void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags) +{ + return slab_alloc(s, gfpflags, -1, __builtin_return_address(0)); +} +EXPORT_SYMBOL(kmem_cache_alloc); + +#ifdef CONFIG_NUMA +void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, int node) +{ + return slab_alloc(s, gfpflags, node, __builtin_return_address(0)); +} +EXPORT_SYMBOL(kmem_cache_alloc_node); +#endif + +/* + * Slow patch handling. This may still be called frequently since objects + * have a longer lifetime than the cpu slabs in most processing loads. + * + * So we still attempt to reduce cache line usage. Just take the slab + * lock and free the item. If there is no additional partial page + * handling required then we can return immediately. + */ +static void __slab_free(struct kmem_cache *s, struct page *page, + void *x, void *addr, unsigned int offset) +{ + void *prior; + void **object = (void *)x; + struct kmem_cache_cpu *c; + + c = get_cpu_slab(s, raw_smp_processor_id()); + stat(c, FREE_SLOWPATH); + slab_lock(page); + + if (unlikely(SLABDEBUG && PageSlubDebug(page))) + goto debug; + +checks_ok: + prior = object[offset] = page->freelist; + page->freelist = object; + page->inuse--; + + if (unlikely(PageSlubFrozen(page))) { + stat(c, FREE_FROZEN); + goto out_unlock; + } + + if (unlikely(!page->inuse)) + goto slab_empty; + + /* + * Objects left in the slab. If it was not on the partial list before + * then add it. + */ + if (unlikely(!prior)) { + add_partial(get_node(s, page_to_nid(page)), page, 1); + stat(c, FREE_ADD_PARTIAL); + } + +out_unlock: + slab_unlock(page); + return; + +slab_empty: + if (prior) { + /* + * Slab still on the partial list. + */ + remove_partial(s, page); + stat(c, FREE_REMOVE_PARTIAL); + } + slab_unlock(page); + stat(c, FREE_SLAB); + discard_slab(s, page); + return; + +debug: + if (!free_debug_processing(s, page, x, addr)) + goto out_unlock; + goto checks_ok; +} + +/* + * Fastpath with forced inlining to produce a kfree and kmem_cache_free that + * can perform fastpath freeing without additional function calls. + * + * The fastpath is only possible if we are freeing to the current cpu slab + * of this processor. This typically the case if we have just allocated + * the item before. + * + * If fastpath is not possible then fall back to __slab_free where we deal + * with all sorts of special processing. + */ +static __always_inline void slab_free(struct kmem_cache *s, + struct page *page, void *x, void *addr) +{ + void **object = (void *)x; + struct kmem_cache_cpu *c; + unsigned long flags; + + local_irq_save(flags); + c = get_cpu_slab(s, smp_processor_id()); + debug_check_no_locks_freed(object, c->objsize); + if (!(s->flags & SLAB_DEBUG_OBJECTS)) + debug_check_no_obj_freed(object, s->objsize); + if (likely(page == c->page && c->node >= 0)) { + object[c->offset] = c->freelist; + c->freelist = object; + stat(c, FREE_FASTPATH); + } else + __slab_free(s, page, x, addr, c->offset); + + local_irq_restore(flags); +} + +void kmem_cache_free(struct kmem_cache *s, void *x) +{ + struct page *page; + + page = virt_to_head_page(x); + + slab_free(s, page, x, __builtin_return_address(0)); +} +EXPORT_SYMBOL(kmem_cache_free); + +/* Figure out on which slab object the object resides */ +static struct page *get_object_page(const void *x) +{ + struct page *page = virt_to_head_page(x); + + if (!PageSlab(page)) + return NULL; + + return page; +} + +/* + * Object placement in a slab is made very easy because we always start at + * offset 0. If we tune the size of the object to the alignment then we can + * get the required alignment by putting one properly sized object after + * another. + * + * Notice that the allocation order determines the sizes of the per cpu + * caches. Each processor has always one slab available for allocations. + * Increasing the allocation order reduces the number of times that slabs + * must be moved on and off the partial lists and is therefore a factor in + * locking overhead. + */ + +/* + * Mininum / Maximum order of slab pages. This influences locking overhead + * and slab fragmentation. A higher order reduces the number of partial slabs + * and increases the number of allocations possible without having to + * take the list_lock. + */ +static int slub_min_order; +static int slub_max_order = PAGE_ALLOC_COSTLY_ORDER; +static int slub_min_objects; + +/* + * Merge control. If this is set then no merging of slab caches will occur. + * (Could be removed. This was introduced to pacify the merge skeptics.) + */ +static int slub_nomerge; + +/* + * Calculate the order of allocation given an slab object size. + * + * The order of allocation has significant impact on performance and other + * system components. Generally order 0 allocations should be preferred since + * order 0 does not cause fragmentation in the page allocator. Larger objects + * be problematic to put into order 0 slabs because there may be too much + * unused space left. We go to a higher order if more than 1/16th of the slab + * would be wasted. + * + * In order to reach satisfactory performance we must ensure that a minimum + * number of objects is in one slab. Otherwise we may generate too much + * activity on the partial lists which requires taking the list_lock. This is + * less a concern for large slabs though which are rarely used. + * + * slub_max_order specifies the order where we begin to stop considering the + * number of objects in a slab as critical. If we reach slub_max_order then + * we try to keep the page order as low as possible. So we accept more waste + * of space in favor of a small page order. + * + * Higher order allocations also allow the placement of more objects in a + * slab and thereby reduce object handling overhead. If the user has + * requested a higher mininum order then we start with that one instead of + * the smallest order which will fit the object. + */ +static inline int slab_order(int size, int min_objects, + int max_order, int fract_leftover) +{ + int order; + int rem; + int min_order = slub_min_order; + + if ((PAGE_SIZE << min_order) / size > 65535) + return get_order(size * 65535) - 1; + + for (order = max(min_order, + fls(min_objects * size - 1) - PAGE_SHIFT); + order <= max_order; order++) { + + unsigned long slab_size = PAGE_SIZE << order; + + if (slab_size < min_objects * size) + continue; + + rem = slab_size % size; + + if (rem <= slab_size / fract_leftover) + break; + + } + + return order; +} + +static inline int calculate_order(int size) +{ + int order; + int min_objects; + int fraction; + + /* + * Attempt to find best configuration for a slab. This + * works by first attempting to generate a layout with + * the best configuration and backing off gradually. + * + * First we reduce the acceptable waste in a slab. Then + * we reduce the minimum objects required in a slab. + */ + min_objects = slub_min_objects; + if (!min_objects) + min_objects = 4 * (fls(nr_cpu_ids) + 1); + while (min_objects > 1) { + fraction = 16; + while (fraction >= 4) { + order = slab_order(size, min_objects, + slub_max_order, fraction); + if (order <= slub_max_order) + return order; + fraction /= 2; + } + min_objects /= 2; + } + + /* + * We were unable to place multiple objects in a slab. Now + * lets see if we can place a single object there. + */ + order = slab_order(size, 1, slub_max_order, 1); + if (order <= slub_max_order) + return order; + + /* + * Doh this slab cannot be placed using slub_max_order. + */ + order = slab_order(size, 1, MAX_ORDER, 1); + if (order <= MAX_ORDER) + return order; + return -ENOSYS; +} + +/* + * Figure out what the alignment of the objects will be. + */ +static unsigned long calculate_alignment(unsigned long flags, + unsigned long align, unsigned long size) +{ + /* + * If the user wants hardware cache aligned objects then follow that + * suggestion if the object is sufficiently large. + * + * The hardware cache alignment cannot override the specified + * alignment though. If that is greater then use it. + */ + if (flags & SLAB_HWCACHE_ALIGN) { + unsigned long ralign = cache_line_size(); + while (size <= ralign / 2) + ralign /= 2; + align = max(align, ralign); + } + + if (align < ARCH_SLAB_MINALIGN) + align = ARCH_SLAB_MINALIGN; + + return ALIGN(align, sizeof(void *)); +} + +static void init_kmem_cache_cpu(struct kmem_cache *s, + struct kmem_cache_cpu *c) +{ + c->page = NULL; + c->freelist = NULL; + c->node = 0; + c->offset = s->offset / sizeof(void *); + c->objsize = s->objsize; +#ifdef CONFIG_SLUB_STATS + memset(c->stat, 0, NR_SLUB_STAT_ITEMS * sizeof(unsigned)); +#endif +} + +static void +init_kmem_cache_node(struct kmem_cache_node *n, struct kmem_cache *s) +{ + n->nr_partial = 0; + + /* + * The larger the object size is, the more pages we want on the partial + * list to avoid pounding the page allocator excessively. + */ + n->min_partial = ilog2(s->size); + if (n->min_partial < MIN_PARTIAL) + n->min_partial = MIN_PARTIAL; + else if (n->min_partial > MAX_PARTIAL) + n->min_partial = MAX_PARTIAL; + + spin_lock_init(&n->list_lock); + INIT_LIST_HEAD(&n->partial); +#ifdef CONFIG_SLUB_DEBUG + atomic_long_set(&n->nr_slabs, 0); + atomic_long_set(&n->total_objects, 0); + INIT_LIST_HEAD(&n->full); +#endif +} + +#ifdef CONFIG_SMP +/* + * Per cpu array for per cpu structures. + * + * The per cpu array places all kmem_cache_cpu structures from one processor + * close together meaning that it becomes possible that multiple per cpu + * structures are contained in one cacheline. This may be particularly + * beneficial for the kmalloc caches. + * + * A desktop system typically has around 60-80 slabs. With 100 here we are + * likely able to get per cpu structures for all caches from the array defined + * here. We must be able to cover all kmalloc caches during bootstrap. + * + * If the per cpu array is exhausted then fall back to kmalloc + * of individual cachelines. No sharing is possible then. + */ +#define NR_KMEM_CACHE_CPU 100 + +static DEFINE_PER_CPU(struct kmem_cache_cpu, + kmem_cache_cpu)[NR_KMEM_CACHE_CPU]; + +static DEFINE_PER_CPU(struct kmem_cache_cpu *, kmem_cache_cpu_free); +static cpumask_t kmem_cach_cpu_free_init_once = CPU_MASK_NONE; + +static struct kmem_cache_cpu *alloc_kmem_cache_cpu(struct kmem_cache *s, + int cpu, gfp_t flags) +{ + struct kmem_cache_cpu *c = per_cpu(kmem_cache_cpu_free, cpu); + + if (c) + per_cpu(kmem_cache_cpu_free, cpu) = + (void *)c->freelist; + else { + /* Table overflow: So allocate ourselves */ + c = kmalloc_node( + ALIGN(sizeof(struct kmem_cache_cpu), cache_line_size()), + flags, cpu_to_node(cpu)); + if (!c) + return NULL; + } + + init_kmem_cache_cpu(s, c); + return c; +} + +static void free_kmem_cache_cpu(struct kmem_cache_cpu *c, int cpu) +{ + if (c < per_cpu(kmem_cache_cpu, cpu) || + c > per_cpu(kmem_cache_cpu, cpu) + NR_KMEM_CACHE_CPU) { + kfree(c); + return; + } + c->freelist = (void *)per_cpu(kmem_cache_cpu_free, cpu); + per_cpu(kmem_cache_cpu_free, cpu) = c; +} + +static void free_kmem_cache_cpus(struct kmem_cache *s) +{ + int cpu; + + for_each_online_cpu(cpu) { + struct kmem_cache_cpu *c = get_cpu_slab(s, cpu); + + if (c) { + s->cpu_slab[cpu] = NULL; + free_kmem_cache_cpu(c, cpu); + } + } +} + +static int alloc_kmem_cache_cpus(struct kmem_cache *s, gfp_t flags) +{ + int cpu; + + for_each_online_cpu(cpu) { + struct kmem_cache_cpu *c = get_cpu_slab(s, cpu); + + if (c) + continue; + + c = alloc_kmem_cache_cpu(s, cpu, flags); + if (!c) { + free_kmem_cache_cpus(s); + return 0; + } + s->cpu_slab[cpu] = c; + } + return 1; +} + +/* + * Initialize the per cpu array. + */ +static void init_alloc_cpu_cpu(int cpu) +{ + int i; + + if (cpu_isset(cpu, kmem_cach_cpu_free_init_once)) + return; + + for (i = NR_KMEM_CACHE_CPU - 1; i >= 0; i--) + free_kmem_cache_cpu(&per_cpu(kmem_cache_cpu, cpu)[i], cpu); + + cpu_set(cpu, kmem_cach_cpu_free_init_once); +} + +static void __init init_alloc_cpu(void) +{ + int cpu; + + for_each_online_cpu(cpu) + init_alloc_cpu_cpu(cpu); + } + +#else +static inline void free_kmem_cache_cpus(struct kmem_cache *s) {} +static inline void init_alloc_cpu(void) {} + +static inline int alloc_kmem_cache_cpus(struct kmem_cache *s, gfp_t flags) +{ + init_kmem_cache_cpu(s, &s->cpu_slab); + return 1; +} +#endif + +#ifdef CONFIG_NUMA +/* + * No kmalloc_node yet so do it by hand. We know that this is the first + * slab on the node for this slabcache. There are no concurrent accesses + * possible. + * + * Note that this function only works on the kmalloc_node_cache + * when allocating for the kmalloc_node_cache. This is used for bootstrapping + * memory on a fresh node that has no slab structures yet. + */ +static struct kmem_cache_node *early_kmem_cache_node_alloc(gfp_t gfpflags, + int node) +{ + struct page *page; + struct kmem_cache_node *n; + unsigned long flags; + + BUG_ON(kmalloc_caches->size < sizeof(struct kmem_cache_node)); + + page = new_slab(kmalloc_caches, gfpflags, node); + + BUG_ON(!page); + if (page_to_nid(page) != node) { + printk(KERN_ERR "SLUB: Unable to allocate memory from " + "node %d\n", node); + printk(KERN_ERR "SLUB: Allocating a useless per node structure " + "in order to be able to continue\n"); + } + + n = page->freelist; + BUG_ON(!n); + page->freelist = get_freepointer(kmalloc_caches, n); + page->inuse++; + kmalloc_caches->node[node] = n; +#ifdef CONFIG_SLUB_DEBUG + init_object(kmalloc_caches, n, 1); + init_tracking(kmalloc_caches, n); +#endif + init_kmem_cache_node(n, kmalloc_caches); + inc_slabs_node(kmalloc_caches, node, page->objects); + + /* + * lockdep requires consistent irq usage for each lock + * so even though there cannot be a race this early in + * the boot sequence, we still disable irqs. + */ + local_irq_save(flags); + add_partial(n, page, 0); + local_irq_restore(flags); + return n; +} + +static void free_kmem_cache_nodes(struct kmem_cache *s) +{ + int node; + + for_each_node_state(node, N_NORMAL_MEMORY) { + struct kmem_cache_node *n = s->node[node]; + if (n && n != &s->local_node) + kmem_cache_free(kmalloc_caches, n); + s->node[node] = NULL; + } +} + +static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags) +{ + int node; + int local_node; + + if (slab_state >= UP) + local_node = page_to_nid(virt_to_page(s)); + else + local_node = 0; + + for_each_node_state(node, N_NORMAL_MEMORY) { + struct kmem_cache_node *n; + + if (local_node == node) + n = &s->local_node; + else { + if (slab_state == DOWN) { + n = early_kmem_cache_node_alloc(gfpflags, + node); + continue; + } + n = kmem_cache_alloc_node(kmalloc_caches, + gfpflags, node); + + if (!n) { + free_kmem_cache_nodes(s); + return 0; + } + + } + s->node[node] = n; + init_kmem_cache_node(n, s); + } + return 1; +} +#else +static void free_kmem_cache_nodes(struct kmem_cache *s) +{ +} + +static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags) +{ + init_kmem_cache_node(&s->local_node, s); + return 1; +} +#endif + +/* + * calculate_sizes() determines the order and the distribution of data within + * a slab object. + */ +static int calculate_sizes(struct kmem_cache *s, int forced_order) +{ + unsigned long flags = s->flags; + unsigned long size = s->objsize; + unsigned long align = s->align; + int order; + + /* + * Round up object size to the next word boundary. We can only + * place the free pointer at word boundaries and this determines + * the possible location of the free pointer. + */ + size = ALIGN(size, sizeof(void *)); + +#ifdef CONFIG_SLUB_DEBUG + /* + * Determine if we can poison the object itself. If the user of + * the slab may touch the object after free or before allocation + * then we should never poison the object itself. + */ + if ((flags & SLAB_POISON) && !(flags & SLAB_DESTROY_BY_RCU) && + !s->ctor) + s->flags |= __OBJECT_POISON; + else + s->flags &= ~__OBJECT_POISON; + + + /* + * If we are Redzoning then check if there is some space between the + * end of the object and the free pointer. If not then add an + * additional word to have some bytes to store Redzone information. + */ + if ((flags & SLAB_RED_ZONE) && size == s->objsize) + size += sizeof(void *); +#endif + + /* + * With that we have determined the number of bytes in actual use + * by the object. This is the potential offset to the free pointer. + */ + s->inuse = size; + + if (((flags & (SLAB_DESTROY_BY_RCU | SLAB_POISON)) || + s->ctor)) { + /* + * Relocate free pointer after the object if it is not + * permitted to overwrite the first word of the object on + * kmem_cache_free. + * + * This is the case if we do RCU, have a constructor or + * destructor or are poisoning the objects. + */ + s->offset = size; + size += sizeof(void *); + } + +#ifdef CONFIG_SLUB_DEBUG + if (flags & SLAB_STORE_USER) + /* + * Need to store information about allocs and frees after + * the object. + */ + size += 2 * sizeof(struct track); + + if (flags & SLAB_RED_ZONE) + /* + * Add some empty padding so that we can catch + * overwrites from earlier objects rather than let + * tracking information or the free pointer be + * corrupted if an user writes before the start + * of the object. + */ + size += sizeof(void *); +#endif + + /* + * Determine the alignment based on various parameters that the + * user specified and the dynamic determination of cache line size + * on bootup. + */ + align = calculate_alignment(flags, align, s->objsize); + + /* + * SLUB stores one object immediately after another beginning from + * offset 0. In order to align the objects we have to simply size + * each object to conform to the alignment. + */ + size = ALIGN(size, align); + s->size = size; + if (forced_order >= 0) + order = forced_order; + else + order = calculate_order(size); + + if (order < 0) + return 0; + + s->allocflags = 0; + if (order) + s->allocflags |= __GFP_COMP; + + if (s->flags & SLAB_CACHE_DMA) + s->allocflags |= SLUB_DMA; + + if (s->flags & SLAB_RECLAIM_ACCOUNT) + s->allocflags |= __GFP_RECLAIMABLE; + + /* + * Determine the number of objects per slab + */ + s->oo = oo_make(order, size); + s->min = oo_make(get_order(size), size); + if (oo_objects(s->oo) > oo_objects(s->max)) + s->max = s->oo; + + return !!oo_objects(s->oo); + +} + +static int kmem_cache_open(struct kmem_cache *s, gfp_t gfpflags, + const char *name, size_t size, + size_t align, unsigned long flags, + void (*ctor)(void *)) +{ + memset(s, 0, kmem_size); + s->name = name; + s->ctor = ctor; + s->objsize = size; + s->align = align; + s->flags = kmem_cache_flags(size, flags, name, ctor); + + if (!calculate_sizes(s, -1)) + goto error; + + s->refcount = 1; +#ifdef CONFIG_NUMA + s->remote_node_defrag_ratio = 1000; +#endif + if (!init_kmem_cache_nodes(s, gfpflags & ~SLUB_DMA)) + goto error; + + if (alloc_kmem_cache_cpus(s, gfpflags & ~SLUB_DMA)) + return 1; + free_kmem_cache_nodes(s); +error: + if (flags & SLAB_PANIC) + panic("Cannot create slab %s size=%lu realsize=%u " + "order=%u offset=%u flags=%lx\n", + s->name, (unsigned long)size, s->size, oo_order(s->oo), + s->offset, flags); + return 0; +} + +/* + * Check if a given pointer is valid + */ +int kmem_ptr_validate(struct kmem_cache *s, const void *object) +{ + struct page *page; + + page = get_object_page(object); + + if (!page || s != page->slab) + /* No slab or wrong slab */ + return 0; + + if (!check_valid_pointer(s, page, object)) + return 0; + + /* + * We could also check if the object is on the slabs freelist. + * But this would be too expensive and it seems that the main + * purpose of kmem_ptr_valid() is to check if the object belongs + * to a certain slab. + */ + return 1; +} +EXPORT_SYMBOL(kmem_ptr_validate); + +/* + * Determine the size of a slab object + */ +unsigned int kmem_cache_size(struct kmem_cache *s) +{ + return s->objsize; +} +EXPORT_SYMBOL(kmem_cache_size); + +const char *kmem_cache_name(struct kmem_cache *s) +{ + return s->name; +} +EXPORT_SYMBOL(kmem_cache_name); + +static void list_slab_objects(struct kmem_cache *s, struct page *page, + const char *text) +{ +#ifdef CONFIG_SLUB_DEBUG + void *addr = page_address(page); + void *p; + DECLARE_BITMAP(map, page->objects); + + bitmap_zero(map, page->objects); + slab_err(s, page, "%s", text); + slab_lock(page); + for_each_free_object(p, s, page->freelist) + set_bit(slab_index(p, s, addr), map); + + for_each_object(p, s, addr, page->objects) { + + if (!test_bit(slab_index(p, s, addr), map)) { + printk(KERN_ERR "INFO: Object 0x%p @offset=%tu\n", + p, p - addr); + print_tracking(s, p); + } + } + slab_unlock(page); +#endif +} + +/* + * Attempt to free all partial slabs on a node. + */ +static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n) +{ + unsigned long flags; + struct page *page, *h; + + spin_lock_irqsave(&n->list_lock, flags); + list_for_each_entry_safe(page, h, &n->partial, lru) { + if (!page->inuse) { + list_del(&page->lru); + discard_slab(s, page); + n->nr_partial--; + } else { + list_slab_objects(s, page, + "Objects remaining on kmem_cache_close()"); + } + } + spin_unlock_irqrestore(&n->list_lock, flags); +} + +/* + * Release all resources used by a slab cache. + */ +static inline int kmem_cache_close(struct kmem_cache *s) +{ + int node; + + flush_all(s); + + /* Attempt to free all objects */ + free_kmem_cache_cpus(s); + for_each_node_state(node, N_NORMAL_MEMORY) { + struct kmem_cache_node *n = get_node(s, node); + + free_partial(s, n); + if (n->nr_partial || slabs_node(s, node)) + return 1; + } + free_kmem_cache_nodes(s); + return 0; +} + +/* + * Close a cache and release the kmem_cache structure + * (must be used for caches created using kmem_cache_create) + */ +void kmem_cache_destroy(struct kmem_cache *s) +{ + down_write(&slub_lock); + s->refcount--; + if (!s->refcount) { + list_del(&s->list); + up_write(&slub_lock); + if (kmem_cache_close(s)) { + printk(KERN_ERR "SLUB %s: %s called for cache that " + "still has objects.\n", s->name, __func__); + dump_stack(); + } + sysfs_slab_remove(s); + } else + up_write(&slub_lock); +} +EXPORT_SYMBOL(kmem_cache_destroy); + +/******************************************************************** + * Kmalloc subsystem + *******************************************************************/ + +struct kmem_cache kmalloc_caches[PAGE_SHIFT + 1] __cacheline_aligned; +EXPORT_SYMBOL(kmalloc_caches); + +static int __init setup_slub_min_order(char *str) +{ + get_option(&str, &slub_min_order); + + return 1; +} + +__setup("slub_min_order=", setup_slub_min_order); + +static int __init setup_slub_max_order(char *str) +{ + get_option(&str, &slub_max_order); + + return 1; +} + +__setup("slub_max_order=", setup_slub_max_order); + +static int __init setup_slub_min_objects(char *str) +{ + get_option(&str, &slub_min_objects); + + return 1; +} + +__setup("slub_min_objects=", setup_slub_min_objects); + +static int __init setup_slub_nomerge(char *str) +{ + slub_nomerge = 1; + return 1; +} + +__setup("slub_nomerge", setup_slub_nomerge); + +static struct kmem_cache *create_kmalloc_cache(struct kmem_cache *s, + const char *name, int size, gfp_t gfp_flags) +{ + unsigned int flags = 0; + + if (gfp_flags & SLUB_DMA) + flags = SLAB_CACHE_DMA; + + down_write(&slub_lock); + if (!kmem_cache_open(s, gfp_flags, name, size, ARCH_KMALLOC_MINALIGN, + flags, NULL)) + goto panic; + + list_add(&s->list, &slab_caches); + up_write(&slub_lock); + if (sysfs_slab_add(s)) + goto panic; + return s; + +panic: + panic("Creation of kmalloc slab %s size=%d failed.\n", name, size); +} + +#ifdef CONFIG_ZONE_DMA +static struct kmem_cache *kmalloc_caches_dma[PAGE_SHIFT + 1]; + +static void sysfs_add_func(struct work_struct *w) +{ + struct kmem_cache *s; + + down_write(&slub_lock); + list_for_each_entry(s, &slab_caches, list) { + if (s->flags & __SYSFS_ADD_DEFERRED) { + s->flags &= ~__SYSFS_ADD_DEFERRED; + sysfs_slab_add(s); + } + } + up_write(&slub_lock); +} + +static DECLARE_WORK(sysfs_add_work, sysfs_add_func); + +static noinline struct kmem_cache *dma_kmalloc_cache(int index, gfp_t flags) +{ + struct kmem_cache *s; + char *text; + size_t realsize; + + s = kmalloc_caches_dma[index]; + if (s) + return s; + + /* Dynamically create dma cache */ + if (flags & __GFP_WAIT) + down_write(&slub_lock); + else { + if (!down_write_trylock(&slub_lock)) + goto out; + } + + if (kmalloc_caches_dma[index]) + goto unlock_out; + + realsize = kmalloc_caches[index].objsize; + text = kasprintf(flags & ~SLUB_DMA, "kmalloc_dma-%d", + (unsigned int)realsize); + s = kmalloc(kmem_size, flags & ~SLUB_DMA); + + if (!s || !text || !kmem_cache_open(s, flags, text, + realsize, ARCH_KMALLOC_MINALIGN, + SLAB_CACHE_DMA|__SYSFS_ADD_DEFERRED, NULL)) { + kfree(s); + kfree(text); + goto unlock_out; + } + + list_add(&s->list, &slab_caches); + kmalloc_caches_dma[index] = s; + + schedule_work(&sysfs_add_work); + +unlock_out: + up_write(&slub_lock); +out: + return kmalloc_caches_dma[index]; +} +#endif + +/* + * Conversion table for small slabs sizes / 8 to the index in the + * kmalloc array. This is necessary for slabs < 192 since we have non power + * of two cache sizes there. The size of larger slabs can be determined using + * fls. + */ +static s8 size_index[24] = { + 3, /* 8 */ + 4, /* 16 */ + 5, /* 24 */ + 5, /* 32 */ + 6, /* 40 */ + 6, /* 48 */ + 6, /* 56 */ + 6, /* 64 */ + 1, /* 72 */ + 1, /* 80 */ + 1, /* 88 */ + 1, /* 96 */ + 7, /* 104 */ + 7, /* 112 */ + 7, /* 120 */ + 7, /* 128 */ + 2, /* 136 */ + 2, /* 144 */ + 2, /* 152 */ + 2, /* 160 */ + 2, /* 168 */ + 2, /* 176 */ + 2, /* 184 */ + 2 /* 192 */ +}; + +static struct kmem_cache *get_slab(size_t size, gfp_t flags) +{ + int index; + + if (size <= 192) { + if (!size) + return ZERO_SIZE_PTR; + + index = size_index[(size - 1) / 8]; + } else + index = fls(size - 1); + +#ifdef CONFIG_ZONE_DMA + if (unlikely((flags & SLUB_DMA))) + return dma_kmalloc_cache(index, flags); + +#endif + return &kmalloc_caches[index]; +} + +void *__kmalloc(size_t size, gfp_t flags) +{ + struct kmem_cache *s; + + if (unlikely(size > PAGE_SIZE)) + return kmalloc_large(size, flags); + + s = get_slab(size, flags); + + if (unlikely(ZERO_OR_NULL_PTR(s))) + return s; + + return slab_alloc(s, flags, -1, __builtin_return_address(0)); +} +EXPORT_SYMBOL(__kmalloc); + +static void *kmalloc_large_node(size_t size, gfp_t flags, int node) +{ + struct page *page = alloc_pages_node(node, flags | __GFP_COMP, + get_order(size)); + + if (page) + return page_address(page); + else + return NULL; +} + +#ifdef CONFIG_NUMA +void *__kmalloc_node(size_t size, gfp_t flags, int node) +{ + struct kmem_cache *s; + + if (unlikely(size > PAGE_SIZE)) + return kmalloc_large_node(size, flags, node); + + s = get_slab(size, flags); + + if (unlikely(ZERO_OR_NULL_PTR(s))) + return s; + + return slab_alloc(s, flags, node, __builtin_return_address(0)); +} +EXPORT_SYMBOL(__kmalloc_node); +#endif + +size_t ksize(const void *object) +{ + struct page *page; + struct kmem_cache *s; + + if (unlikely(object == ZERO_SIZE_PTR)) + return 0; + + page = virt_to_head_page(object); + + if (unlikely(!PageSlab(page))) { + WARN_ON(!PageCompound(page)); + return PAGE_SIZE << compound_order(page); + } + s = page->slab; + +#ifdef CONFIG_SLUB_DEBUG + /* + * Debugging requires use of the padding between object + * and whatever may come after it. + */ + if (s->flags & (SLAB_RED_ZONE | SLAB_POISON)) + return s->objsize; + +#endif + /* + * If we have the need to store the freelist pointer + * back there or track user information then we can + * only use the space before that information. + */ + if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER)) + return s->inuse; + /* + * Else we can use all the padding etc for the allocation + */ + return s->size; +} + +void kfree(const void *x) +{ + struct page *page; + void *object = (void *)x; + + if (unlikely(ZERO_OR_NULL_PTR(x))) + return; + + page = virt_to_head_page(x); + if (unlikely(!PageSlab(page))) { + BUG_ON(!PageCompound(page)); + put_page(page); + return; + } + slab_free(page->slab, page, object, __builtin_return_address(0)); +} +EXPORT_SYMBOL(kfree); + +/* + * kmem_cache_shrink removes empty slabs from the partial lists and sorts + * the remaining slabs by the number of items in use. The slabs with the + * most items in use come first. New allocations will then fill those up + * and thus they can be removed from the partial lists. + * + * The slabs with the least items are placed last. This results in them + * being allocated from last increasing the chance that the last objects + * are freed in them. + */ +int kmem_cache_shrink(struct kmem_cache *s) +{ + int node; + int i; + struct kmem_cache_node *n; + struct page *page; + struct page *t; + int objects = oo_objects(s->max); + struct list_head *slabs_by_inuse = + kmalloc(sizeof(struct list_head) * objects, GFP_KERNEL); + unsigned long flags; + + if (!slabs_by_inuse) + return -ENOMEM; + + flush_all(s); + for_each_node_state(node, N_NORMAL_MEMORY) { + n = get_node(s, node); + + if (!n->nr_partial) + continue; + + for (i = 0; i < objects; i++) + INIT_LIST_HEAD(slabs_by_inuse + i); + + spin_lock_irqsave(&n->list_lock, flags); + + /* + * Build lists indexed by the items in use in each slab. + * + * Note that concurrent frees may occur while we hold the + * list_lock. page->inuse here is the upper limit. + */ + list_for_each_entry_safe(page, t, &n->partial, lru) { + if (!page->inuse && slab_trylock(page)) { + /* + * Must hold slab lock here because slab_free + * may have freed the last object and be + * waiting to release the slab. + */ + list_del(&page->lru); + n->nr_partial--; + slab_unlock(page); + discard_slab(s, page); + } else { + list_move(&page->lru, + slabs_by_inuse + page->inuse); + } + } + + /* + * Rebuild the partial list with the slabs filled up most + * first and the least used slabs at the end. + */ + for (i = objects - 1; i >= 0; i--) + list_splice(slabs_by_inuse + i, n->partial.prev); + + spin_unlock_irqrestore(&n->list_lock, flags); + } + + kfree(slabs_by_inuse); + return 0; +} +EXPORT_SYMBOL(kmem_cache_shrink); + +#if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG) +static int slab_mem_going_offline_callback(void *arg) +{ + struct kmem_cache *s; + + down_read(&slub_lock); + list_for_each_entry(s, &slab_caches, list) + kmem_cache_shrink(s); + up_read(&slub_lock); + + return 0; +} + +static void slab_mem_offline_callback(void *arg) +{ + struct kmem_cache_node *n; + struct kmem_cache *s; + struct memory_notify *marg = arg; + int offline_node; + + offline_node = marg->status_change_nid; + + /* + * If the node still has available memory. we need kmem_cache_node + * for it yet. + */ + if (offline_node < 0) + return; + + down_read(&slub_lock); + list_for_each_entry(s, &slab_caches, list) { + n = get_node(s, offline_node); + if (n) { + /* + * if n->nr_slabs > 0, slabs still exist on the node + * that is going down. We were unable to free them, + * and offline_pages() function shoudn't call this + * callback. So, we must fail. + */ + BUG_ON(slabs_node(s, offline_node)); + + s->node[offline_node] = NULL; + kmem_cache_free(kmalloc_caches, n); + } + } + up_read(&slub_lock); +} + +static int slab_mem_going_online_callback(void *arg) +{ + struct kmem_cache_node *n; + struct kmem_cache *s; + struct memory_notify *marg = arg; + int nid = marg->status_change_nid; + int ret = 0; + + /* + * If the node's memory is already available, then kmem_cache_node is + * already created. Nothing to do. + */ + if (nid < 0) + return 0; + + /* + * We are bringing a node online. No memory is available yet. We must + * allocate a kmem_cache_node structure in order to bring the node + * online. + */ + down_read(&slub_lock); + list_for_each_entry(s, &slab_caches, list) { + /* + * XXX: kmem_cache_alloc_node will fallback to other nodes + * since memory is not yet available from the node that + * is brought up. + */ + n = kmem_cache_alloc(kmalloc_caches, GFP_KERNEL); + if (!n) { + ret = -ENOMEM; + goto out; + } + init_kmem_cache_node(n, s); + s->node[nid] = n; + } +out: + up_read(&slub_lock); + return ret; +} + +static int slab_memory_callback(struct notifier_block *self, + unsigned long action, void *arg) +{ + int ret = 0; + + switch (action) { + case MEM_GOING_ONLINE: + ret = slab_mem_going_online_callback(arg); + break; + case MEM_GOING_OFFLINE: + ret = slab_mem_going_offline_callback(arg); + break; + case MEM_OFFLINE: + case MEM_CANCEL_ONLINE: + slab_mem_offline_callback(arg); + break; + case MEM_ONLINE: + case MEM_CANCEL_OFFLINE: + break; + } + if (ret) + ret = notifier_from_errno(ret); + else + ret = NOTIFY_OK; + return ret; +} + +#endif /* CONFIG_MEMORY_HOTPLUG */ + +/******************************************************************** + * Basic setup of slabs + *******************************************************************/ + +void __init kmem_cache_init(void) +{ + int i; + int caches = 0; + + init_alloc_cpu(); + +#ifdef CONFIG_NUMA + /* + * Must first have the slab cache available for the allocations of the + * struct kmem_cache_node's. There is special bootstrap code in + * kmem_cache_open for slab_state == DOWN. + */ + create_kmalloc_cache(&kmalloc_caches[0], "kmem_cache_node", + sizeof(struct kmem_cache_node), GFP_KERNEL); + kmalloc_caches[0].refcount = -1; + caches++; + + hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI); +#endif + + /* Able to allocate the per node structures */ + slab_state = PARTIAL; + + /* Caches that are not of the two-to-the-power-of size */ + if (KMALLOC_MIN_SIZE <= 64) { + create_kmalloc_cache(&kmalloc_caches[1], + "kmalloc-96", 96, GFP_KERNEL); + caches++; + create_kmalloc_cache(&kmalloc_caches[2], + "kmalloc-192", 192, GFP_KERNEL); + caches++; + } + + for (i = KMALLOC_SHIFT_LOW; i <= PAGE_SHIFT; i++) { + create_kmalloc_cache(&kmalloc_caches[i], + "kmalloc", 1 << i, GFP_KERNEL); + caches++; + } + + + /* + * Patch up the size_index table if we have strange large alignment + * requirements for the kmalloc array. This is only the case for + * MIPS it seems. The standard arches will not generate any code here. + * + * Largest permitted alignment is 256 bytes due to the way we + * handle the index determination for the smaller caches. + * + * Make sure that nothing crazy happens if someone starts tinkering + * around with ARCH_KMALLOC_MINALIGN + */ + BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 || + (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1))); + + for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) + size_index[(i - 1) / 8] = KMALLOC_SHIFT_LOW; + + if (KMALLOC_MIN_SIZE == 128) { + /* + * The 192 byte sized cache is not used if the alignment + * is 128 byte. Redirect kmalloc to use the 256 byte cache + * instead. + */ + for (i = 128 + 8; i <= 192; i += 8) + size_index[(i - 1) / 8] = 8; + } + + slab_state = UP; + + /* Provide the correct kmalloc names now that the caches are up */ + for (i = KMALLOC_SHIFT_LOW; i <= PAGE_SHIFT; i++) + kmalloc_caches[i]. name = + kasprintf(GFP_KERNEL, "kmalloc-%d", 1 << i); + +#ifdef CONFIG_SMP + register_cpu_notifier(&slab_notifier); + kmem_size = offsetof(struct kmem_cache, cpu_slab) + + nr_cpu_ids * sizeof(struct kmem_cache_cpu *); +#else + kmem_size = sizeof(struct kmem_cache); +#endif + + printk(KERN_INFO + "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d," + " CPUs=%d, Nodes=%d\n", + caches, cache_line_size(), + slub_min_order, slub_max_order, slub_min_objects, + nr_cpu_ids, nr_node_ids); +} + +/* + * Find a mergeable slab cache + */ +static int slab_unmergeable(struct kmem_cache *s) +{ + if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE)) + return 1; + + if (s->ctor) + return 1; + + /* + * We may have set a slab to be unmergeable during bootstrap. + */ + if (s->refcount < 0) + return 1; + + return 0; +} + +static struct kmem_cache *find_mergeable(size_t size, + size_t align, unsigned long flags, const char *name, + void (*ctor)(void *)) +{ + struct kmem_cache *s; + + if (slub_nomerge || (flags & SLUB_NEVER_MERGE)) + return NULL; + + if (ctor) + return NULL; + + size = ALIGN(size, sizeof(void *)); + align = calculate_alignment(flags, align, size); + size = ALIGN(size, align); + flags = kmem_cache_flags(size, flags, name, NULL); + + list_for_each_entry(s, &slab_caches, list) { + if (slab_unmergeable(s)) + continue; + + if (size > s->size) + continue; + + if ((flags & SLUB_MERGE_SAME) != (s->flags & SLUB_MERGE_SAME)) + continue; + /* + * Check if alignment is compatible. + * Courtesy of Adrian Drzewiecki + */ + if ((s->size & ~(align - 1)) != s->size) + continue; + + if (s->size - size >= sizeof(void *)) + continue; + + return s; + } + return NULL; +} + +struct kmem_cache *kmem_cache_create(const char *name, size_t size, + size_t align, unsigned long flags, void (*ctor)(void *)) +{ + struct kmem_cache *s; + + down_write(&slub_lock); + s = find_mergeable(size, align, flags, name, ctor); + if (s) { + int cpu; + + s->refcount++; + /* + * Adjust the object sizes so that we clear + * the complete object on kzalloc. + */ + s->objsize = max(s->objsize, (int)size); + + /* + * And then we need to update the object size in the + * per cpu structures + */ + for_each_online_cpu(cpu) + get_cpu_slab(s, cpu)->objsize = s->objsize; + + s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *))); + up_write(&slub_lock); + + if (sysfs_slab_alias(s, name)) + goto err; + return s; + } + + s = kmalloc(kmem_size, GFP_KERNEL); + if (s) { + if (kmem_cache_open(s, GFP_KERNEL, name, + size, align, flags, ctor)) { + list_add(&s->list, &slab_caches); + up_write(&slub_lock); + if (sysfs_slab_add(s)) + goto err; + return s; + } + kfree(s); + } + up_write(&slub_lock); + +err: + if (flags & SLAB_PANIC) + panic("Cannot create slabcache %s\n", name); + else + s = NULL; + return s; +} +EXPORT_SYMBOL(kmem_cache_create); + +#ifdef CONFIG_SMP +/* + * Use the cpu notifier to insure that the cpu slabs are flushed when + * necessary. + */ +static int __cpuinit slab_cpuup_callback(struct notifier_block *nfb, + unsigned long action, void *hcpu) +{ + long cpu = (long)hcpu; + struct kmem_cache *s; + unsigned long flags; + + switch (action) { + case CPU_UP_PREPARE: + case CPU_UP_PREPARE_FROZEN: + init_alloc_cpu_cpu(cpu); + down_read(&slub_lock); + list_for_each_entry(s, &slab_caches, list) + s->cpu_slab[cpu] = alloc_kmem_cache_cpu(s, cpu, + GFP_KERNEL); + up_read(&slub_lock); + break; + + case CPU_UP_CANCELED: + case CPU_UP_CANCELED_FROZEN: + case CPU_DEAD: + case CPU_DEAD_FROZEN: + down_read(&slub_lock); + list_for_each_entry(s, &slab_caches, list) { + struct kmem_cache_cpu *c = get_cpu_slab(s, cpu); + + local_irq_save(flags); + __flush_cpu_slab(s, cpu); + local_irq_restore(flags); + free_kmem_cache_cpu(c, cpu); + s->cpu_slab[cpu] = NULL; + } + up_read(&slub_lock); + break; + default: + break; + } + return NOTIFY_OK; +} + +static struct notifier_block __cpuinitdata slab_notifier = { + .notifier_call = slab_cpuup_callback +}; + +#endif + +void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, void *caller) +{ + struct kmem_cache *s; + + if (unlikely(size > PAGE_SIZE)) + return kmalloc_large(size, gfpflags); + + s = get_slab(size, gfpflags); + + if (unlikely(ZERO_OR_NULL_PTR(s))) + return s; + + return slab_alloc(s, gfpflags, -1, caller); +} + +void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags, + int node, void *caller) +{ + struct kmem_cache *s; + + if (unlikely(size > PAGE_SIZE)) + return kmalloc_large_node(size, gfpflags, node); + + s = get_slab(size, gfpflags); + + if (unlikely(ZERO_OR_NULL_PTR(s))) + return s; + + return slab_alloc(s, gfpflags, node, caller); +} + +#ifdef CONFIG_SLUB_DEBUG +static unsigned long count_partial(struct kmem_cache_node *n, + int (*get_count)(struct page *)) +{ + unsigned long flags; + unsigned long x = 0; + struct page *page; + + spin_lock_irqsave(&n->list_lock, flags); + list_for_each_entry(page, &n->partial, lru) + x += get_count(page); + spin_unlock_irqrestore(&n->list_lock, flags); + return x; +} + +static int count_inuse(struct page *page) +{ + return page->inuse; +} + +static int count_total(struct page *page) +{ + return page->objects; +} + +static int count_free(struct page *page) +{ + return page->objects - page->inuse; +} + +static int validate_slab(struct kmem_cache *s, struct page *page, + unsigned long *map) +{ + void *p; + void *addr = page_address(page); + + if (!check_slab(s, page) || + !on_freelist(s, page, NULL)) + return 0; + + /* Now we know that a valid freelist exists */ + bitmap_zero(map, page->objects); + + for_each_free_object(p, s, page->freelist) { + set_bit(slab_index(p, s, addr), map); + if (!check_object(s, page, p, 0)) + return 0; + } + + for_each_object(p, s, addr, page->objects) + if (!test_bit(slab_index(p, s, addr), map)) + if (!check_object(s, page, p, 1)) + return 0; + return 1; +} + +static void validate_slab_slab(struct kmem_cache *s, struct page *page, + unsigned long *map) +{ + if (slab_trylock(page)) { + validate_slab(s, page, map); + slab_unlock(page); + } else + printk(KERN_INFO "SLUB %s: Skipped busy slab 0x%p\n", + s->name, page); + + if (s->flags & DEBUG_DEFAULT_FLAGS) { + if (!PageSlubDebug(page)) + printk(KERN_ERR "SLUB %s: SlubDebug not set " + "on slab 0x%p\n", s->name, page); + } else { + if (PageSlubDebug(page)) + printk(KERN_ERR "SLUB %s: SlubDebug set on " + "slab 0x%p\n", s->name, page); + } +} + +static int validate_slab_node(struct kmem_cache *s, + struct kmem_cache_node *n, unsigned long *map) +{ + unsigned long count = 0; + struct page *page; + unsigned long flags; + + spin_lock_irqsave(&n->list_lock, flags); + + list_for_each_entry(page, &n->partial, lru) { + validate_slab_slab(s, page, map); + count++; + } + if (count != n->nr_partial) + printk(KERN_ERR "SLUB %s: %ld partial slabs counted but " + "counter=%ld\n", s->name, count, n->nr_partial); + + if (!(s->flags & SLAB_STORE_USER)) + goto out; + + list_for_each_entry(page, &n->full, lru) { + validate_slab_slab(s, page, map); + count++; + } + if (count != atomic_long_read(&n->nr_slabs)) + printk(KERN_ERR "SLUB: %s %ld slabs counted but " + "counter=%ld\n", s->name, count, + atomic_long_read(&n->nr_slabs)); + +out: + spin_unlock_irqrestore(&n->list_lock, flags); + return count; +} + +static long validate_slab_cache(struct kmem_cache *s) +{ + int node; + unsigned long count = 0; + unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) * + sizeof(unsigned long), GFP_KERNEL); + + if (!map) + return -ENOMEM; + + flush_all(s); + for_each_node_state(node, N_NORMAL_MEMORY) { + struct kmem_cache_node *n = get_node(s, node); + + count += validate_slab_node(s, n, map); + } + kfree(map); + return count; +} + +#ifdef SLUB_RESILIENCY_TEST +static void resiliency_test(void) +{ + u8 *p; + + printk(KERN_ERR "SLUB resiliency testing\n"); + printk(KERN_ERR "-----------------------\n"); + printk(KERN_ERR "A. Corruption after allocation\n"); + + p = kzalloc(16, GFP_KERNEL); + p[16] = 0x12; + printk(KERN_ERR "\n1. kmalloc-16: Clobber Redzone/next pointer" + " 0x12->0x%p\n\n", p + 16); + + validate_slab_cache(kmalloc_caches + 4); + + /* Hmmm... The next two are dangerous */ + p = kzalloc(32, GFP_KERNEL); + p[32 + sizeof(void *)] = 0x34; + printk(KERN_ERR "\n2. kmalloc-32: Clobber next pointer/next slab" + " 0x34 -> -0x%p\n", p); + printk(KERN_ERR + "If allocated object is overwritten then not detectable\n\n"); + + validate_slab_cache(kmalloc_caches + 5); + p = kzalloc(64, GFP_KERNEL); + p += 64 + (get_cycles() & 0xff) * sizeof(void *); + *p = 0x56; + printk(KERN_ERR "\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n", + p); + printk(KERN_ERR + "If allocated object is overwritten then not detectable\n\n"); + validate_slab_cache(kmalloc_caches + 6); + + printk(KERN_ERR "\nB. Corruption after free\n"); + p = kzalloc(128, GFP_KERNEL); + kfree(p); + *p = 0x78; + printk(KERN_ERR "1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p); + validate_slab_cache(kmalloc_caches + 7); + + p = kzalloc(256, GFP_KERNEL); + kfree(p); + p[50] = 0x9a; + printk(KERN_ERR "\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n", + p); + validate_slab_cache(kmalloc_caches + 8); + + p = kzalloc(512, GFP_KERNEL); + kfree(p); + p[512] = 0xab; + printk(KERN_ERR "\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p); + validate_slab_cache(kmalloc_caches + 9); +} +#else +static void resiliency_test(void) {}; +#endif + +/* + * Generate lists of code addresses where slabcache objects are allocated + * and freed. + */ + +struct location { + unsigned long count; + void *addr; + long long sum_time; + long min_time; + long max_time; + long min_pid; + long max_pid; + cpumask_t cpus; + nodemask_t nodes; +}; + +struct loc_track { + unsigned long max; + unsigned long count; + struct location *loc; +}; + +static void free_loc_track(struct loc_track *t) +{ + if (t->max) + free_pages((unsigned long)t->loc, + get_order(sizeof(struct location) * t->max)); +} + +static int alloc_loc_track(struct loc_track *t, unsigned long max, gfp_t flags) +{ + struct location *l; + int order; + + order = get_order(sizeof(struct location) * max); + + l = (void *)__get_free_pages(flags, order); + if (!l) + return 0; + + if (t->count) { + memcpy(l, t->loc, sizeof(struct location) * t->count); + free_loc_track(t); + } + t->max = max; + t->loc = l; + return 1; +} + +static int add_location(struct loc_track *t, struct kmem_cache *s, + const struct track *track) +{ + long start, end, pos; + struct location *l; + void *caddr; + unsigned long age = jiffies - track->when; + + start = -1; + end = t->count; + + for ( ; ; ) { + pos = start + (end - start + 1) / 2; + + /* + * There is nothing at "end". If we end up there + * we need to add something to before end. + */ + if (pos == end) + break; + + caddr = t->loc[pos].addr; + if (track->addr == caddr) { + + l = &t->loc[pos]; + l->count++; + if (track->when) { + l->sum_time += age; + if (age < l->min_time) + l->min_time = age; + if (age > l->max_time) + l->max_time = age; + + if (track->pid < l->min_pid) + l->min_pid = track->pid; + if (track->pid > l->max_pid) + l->max_pid = track->pid; + + cpu_set(track->cpu, l->cpus); + } + node_set(page_to_nid(virt_to_page(track)), l->nodes); + return 1; + } + + if (track->addr < caddr) + end = pos; + else + start = pos; + } + + /* + * Not found. Insert new tracking element. + */ + if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max, GFP_ATOMIC)) + return 0; + + l = t->loc + pos; + if (pos < t->count) + memmove(l + 1, l, + (t->count - pos) * sizeof(struct location)); + t->count++; + l->count = 1; + l->addr = track->addr; + l->sum_time = age; + l->min_time = age; + l->max_time = age; + l->min_pid = track->pid; + l->max_pid = track->pid; + cpus_clear(l->cpus); + cpu_set(track->cpu, l->cpus); + nodes_clear(l->nodes); + node_set(page_to_nid(virt_to_page(track)), l->nodes); + return 1; +} + +static void process_slab(struct loc_track *t, struct kmem_cache *s, + struct page *page, enum track_item alloc) +{ + void *addr = page_address(page); + DECLARE_BITMAP(map, page->objects); + void *p; + + bitmap_zero(map, page->objects); + for_each_free_object(p, s, page->freelist) + set_bit(slab_index(p, s, addr), map); + + for_each_object(p, s, addr, page->objects) + if (!test_bit(slab_index(p, s, addr), map)) + add_location(t, s, get_track(s, p, alloc)); +} + +static int list_locations(struct kmem_cache *s, char *buf, + enum track_item alloc) +{ + int len = 0; + unsigned long i; + struct loc_track t = { 0, 0, NULL }; + int node; + + if (!alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location), + GFP_TEMPORARY)) + return sprintf(buf, "Out of memory\n"); + + /* Push back cpu slabs */ + flush_all(s); + + for_each_node_state(node, N_NORMAL_MEMORY) { + struct kmem_cache_node *n = get_node(s, node); + unsigned long flags; + struct page *page; + + if (!atomic_long_read(&n->nr_slabs)) + continue; + + spin_lock_irqsave(&n->list_lock, flags); + list_for_each_entry(page, &n->partial, lru) + process_slab(&t, s, page, alloc); + list_for_each_entry(page, &n->full, lru) + process_slab(&t, s, page, alloc); + spin_unlock_irqrestore(&n->list_lock, flags); + } + + for (i = 0; i < t.count; i++) { + struct location *l = &t.loc[i]; + + if (len > PAGE_SIZE - KSYM_SYMBOL_LEN - 100) + break; + len += sprintf(buf + len, "%7ld ", l->count); + + if (l->addr) + len += sprint_symbol(buf + len, (unsigned long)l->addr); + else + len += sprintf(buf + len, "<not-available>"); + + if (l->sum_time != l->min_time) { + len += sprintf(buf + len, " age=%ld/%ld/%ld", + l->min_time, + (long)div_u64(l->sum_time, l->count), + l->max_time); + } else + len += sprintf(buf + len, " age=%ld", + l->min_time); + + if (l->min_pid != l->max_pid) + len += sprintf(buf + len, " pid=%ld-%ld", + l->min_pid, l->max_pid); + else + len += sprintf(buf + len, " pid=%ld", + l->min_pid); + + if (num_online_cpus() > 1 && !cpus_empty(l->cpus) && + len < PAGE_SIZE - 60) { + len += sprintf(buf + len, " cpus="); + len += cpulist_scnprintf(buf + len, PAGE_SIZE - len - 50, + l->cpus); + } + + if (num_online_nodes() > 1 && !nodes_empty(l->nodes) && + len < PAGE_SIZE - 60) { + len += sprintf(buf + len, " nodes="); + len += nodelist_scnprintf(buf + len, PAGE_SIZE - len - 50, + l->nodes); + } + + len += sprintf(buf + len, "\n"); + } + + free_loc_track(&t); + if (!t.count) + len += sprintf(buf, "No data\n"); + return len; +} + +enum slab_stat_type { + SL_ALL, /* All slabs */ + SL_PARTIAL, /* Only partially allocated slabs */ + SL_CPU, /* Only slabs used for cpu caches */ + SL_OBJECTS, /* Determine allocated objects not slabs */ + SL_TOTAL /* Determine object capacity not slabs */ +}; + +#define SO_ALL (1 << SL_ALL) +#define SO_PARTIAL (1 << SL_PARTIAL) +#define SO_CPU (1 << SL_CPU) +#define SO_OBJECTS (1 << SL_OBJECTS) +#define SO_TOTAL (1 << SL_TOTAL) + +static ssize_t show_slab_objects(struct kmem_cache *s, + char *buf, unsigned long flags) +{ + unsigned long total = 0; + int node; + int x; + unsigned long *nodes; + unsigned long *per_cpu; + + nodes = kzalloc(2 * sizeof(unsigned long) * nr_node_ids, GFP_KERNEL); + if (!nodes) + return -ENOMEM; + per_cpu = nodes + nr_node_ids; + + if (flags & SO_CPU) { + int cpu; + + for_each_possible_cpu(cpu) { + struct kmem_cache_cpu *c = get_cpu_slab(s, cpu); + + if (!c || c->node < 0) + continue; + + if (c->page) { + if (flags & SO_TOTAL) + x = c->page->objects; + else if (flags & SO_OBJECTS) + x = c->page->inuse; + else + x = 1; + + total += x; + nodes[c->node] += x; + } + per_cpu[c->node]++; + } + } + + if (flags & SO_ALL) { + for_each_node_state(node, N_NORMAL_MEMORY) { + struct kmem_cache_node *n = get_node(s, node); + + if (flags & SO_TOTAL) + x = atomic_long_read(&n->total_objects); + else if (flags & SO_OBJECTS) + x = atomic_long_read(&n->total_objects) - + count_partial(n, count_free); + + else + x = atomic_long_read(&n->nr_slabs); + total += x; + nodes[node] += x; + } + + } else if (flags & SO_PARTIAL) { + for_each_node_state(node, N_NORMAL_MEMORY) { + struct kmem_cache_node *n = get_node(s, node); + + if (flags & SO_TOTAL) + x = count_partial(n, count_total); + else if (flags & SO_OBJECTS) + x = count_partial(n, count_inuse); + else + x = n->nr_partial; + total += x; + nodes[node] += x; + } + } + x = sprintf(buf, "%lu", total); +#ifdef CONFIG_NUMA + for_each_node_state(node, N_NORMAL_MEMORY) + if (nodes[node]) + x += sprintf(buf + x, " N%d=%lu", + node, nodes[node]); +#endif + kfree(nodes); + return x + sprintf(buf + x, "\n"); +} + +static int any_slab_objects(struct kmem_cache *s) +{ + int node; + + for_each_online_node(node) { + struct kmem_cache_node *n = get_node(s, node); + + if (!n) + continue; + + if (atomic_long_read(&n->total_objects)) + return 1; + } + return 0; +} + +#define to_slab_attr(n) container_of(n, struct slab_attribute, attr) +#define to_slab(n) container_of(n, struct kmem_cache, kobj); + +struct slab_attribute { + struct attribute attr; + ssize_t (*show)(struct kmem_cache *s, char *buf); + ssize_t (*store)(struct kmem_cache *s, const char *x, size_t count); +}; + +#define SLAB_ATTR_RO(_name) \ + static struct slab_attribute _name##_attr = __ATTR_RO(_name) + +#define SLAB_ATTR(_name) \ + static struct slab_attribute _name##_attr = \ + __ATTR(_name, 0644, _name##_show, _name##_store) + +static ssize_t slab_size_show(struct kmem_cache *s, char *buf) +{ + return sprintf(buf, "%d\n", s->size); +} +SLAB_ATTR_RO(slab_size); + +static ssize_t align_show(struct kmem_cache *s, char *buf) +{ + return sprintf(buf, "%d\n", s->align); +} +SLAB_ATTR_RO(align); + +static ssize_t object_size_show(struct kmem_cache *s, char *buf) +{ + return sprintf(buf, "%d\n", s->objsize); +} +SLAB_ATTR_RO(object_size); + +static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf) +{ + return sprintf(buf, "%d\n", oo_objects(s->oo)); +} +SLAB_ATTR_RO(objs_per_slab); + +static ssize_t order_store(struct kmem_cache *s, + const char *buf, size_t length) +{ + unsigned long order; + int err; + + err = strict_strtoul(buf, 10, &order); + if (err) + return err; + + if (order > slub_max_order || order < slub_min_order) + return -EINVAL; + + calculate_sizes(s, order); + return length; +} + +static ssize_t order_show(struct kmem_cache *s, char *buf) +{ + return sprintf(buf, "%d\n", oo_order(s->oo)); +} +SLAB_ATTR(order); + +static ssize_t ctor_show(struct kmem_cache *s, char *buf) +{ + if (s->ctor) { + int n = sprint_symbol(buf, (unsigned long)s->ctor); + + return n + sprintf(buf + n, "\n"); + } + return 0; +} +SLAB_ATTR_RO(ctor); + +static ssize_t aliases_show(struct kmem_cache *s, char *buf) +{ + return sprintf(buf, "%d\n", s->refcount - 1); +} +SLAB_ATTR_RO(aliases); + +static ssize_t slabs_show(struct kmem_cache *s, char *buf) +{ + return show_slab_objects(s, buf, SO_ALL); +} +SLAB_ATTR_RO(slabs); + +static ssize_t partial_show(struct kmem_cache *s, char *buf) +{ + return show_slab_objects(s, buf, SO_PARTIAL); +} +SLAB_ATTR_RO(partial); + +static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf) +{ + return show_slab_objects(s, buf, SO_CPU); +} +SLAB_ATTR_RO(cpu_slabs); + +static ssize_t objects_show(struct kmem_cache *s, char *buf) +{ + return show_slab_objects(s, buf, SO_ALL|SO_OBJECTS); +} +SLAB_ATTR_RO(objects); + +static ssize_t objects_partial_show(struct kmem_cache *s, char *buf) +{ + return show_slab_objects(s, buf, SO_PARTIAL|SO_OBJECTS); +} +SLAB_ATTR_RO(objects_partial); + +static ssize_t total_objects_show(struct kmem_cache *s, char *buf) +{ + return show_slab_objects(s, buf, SO_ALL|SO_TOTAL); +} +SLAB_ATTR_RO(total_objects); + +static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf) +{ + return sprintf(buf, "%d\n", !!(s->flags & SLAB_DEBUG_FREE)); +} + +static ssize_t sanity_checks_store(struct kmem_cache *s, + const char *buf, size_t length) +{ + s->flags &= ~SLAB_DEBUG_FREE; + if (buf[0] == '1') + s->flags |= SLAB_DEBUG_FREE; + return length; +} +SLAB_ATTR(sanity_checks); + +static ssize_t trace_show(struct kmem_cache *s, char *buf) +{ + return sprintf(buf, "%d\n", !!(s->flags & SLAB_TRACE)); +} + +static ssize_t trace_store(struct kmem_cache *s, const char *buf, + size_t length) +{ + s->flags &= ~SLAB_TRACE; + if (buf[0] == '1') + s->flags |= SLAB_TRACE; + return length; +} +SLAB_ATTR(trace); + +static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf) +{ + return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT)); +} + +static ssize_t reclaim_account_store(struct kmem_cache *s, + const char *buf, size_t length) +{ + s->flags &= ~SLAB_RECLAIM_ACCOUNT; + if (buf[0] == '1') + s->flags |= SLAB_RECLAIM_ACCOUNT; + return length; +} +SLAB_ATTR(reclaim_account); + +static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf) +{ + return sprintf(buf, "%d\n", !!(s->flags & SLAB_HWCACHE_ALIGN)); +} +SLAB_ATTR_RO(hwcache_align); + +#ifdef CONFIG_ZONE_DMA +static ssize_t cache_dma_show(struct kmem_cache *s, char *buf) +{ + return sprintf(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA)); +} +SLAB_ATTR_RO(cache_dma); +#endif + +static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf) +{ + return sprintf(buf, "%d\n", !!(s->flags & SLAB_DESTROY_BY_RCU)); +} +SLAB_ATTR_RO(destroy_by_rcu); + +static ssize_t red_zone_show(struct kmem_cache *s, char *buf) +{ + return sprintf(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE)); +} + +static ssize_t red_zone_store(struct kmem_cache *s, + const char *buf, size_t length) +{ + if (any_slab_objects(s)) + return -EBUSY; + + s->flags &= ~SLAB_RED_ZONE; + if (buf[0] == '1') + s->flags |= SLAB_RED_ZONE; + calculate_sizes(s, -1); + return length; +} +SLAB_ATTR(red_zone); + +static ssize_t poison_show(struct kmem_cache *s, char *buf) +{ + return sprintf(buf, "%d\n", !!(s->flags & SLAB_POISON)); +} + +static ssize_t poison_store(struct kmem_cache *s, + const char *buf, size_t length) +{ + if (any_slab_objects(s)) + return -EBUSY; + + s->flags &= ~SLAB_POISON; + if (buf[0] == '1') + s->flags |= SLAB_POISON; + calculate_sizes(s, -1); + return length; +} +SLAB_ATTR(poison); + +static ssize_t store_user_show(struct kmem_cache *s, char *buf) +{ + return sprintf(buf, "%d\n", !!(s->flags & SLAB_STORE_USER)); +} + +static ssize_t store_user_store(struct kmem_cache *s, + const char *buf, size_t length) +{ + if (any_slab_objects(s)) + return -EBUSY; + + s->flags &= ~SLAB_STORE_USER; + if (buf[0] == '1') + s->flags |= SLAB_STORE_USER; + calculate_sizes(s, -1); + return length; +} +SLAB_ATTR(store_user); + +static ssize_t validate_show(struct kmem_cache *s, char *buf) +{ + return 0; +} + +static ssize_t validate_store(struct kmem_cache *s, + const char *buf, size_t length) +{ + int ret = -EINVAL; + + if (buf[0] == '1') { + ret = validate_slab_cache(s); + if (ret >= 0) + ret = length; + } + return ret; +} +SLAB_ATTR(validate); + +static ssize_t shrink_show(struct kmem_cache *s, char *buf) +{ + return 0; +} + +static ssize_t shrink_store(struct kmem_cache *s, + const char *buf, size_t length) +{ + if (buf[0] == '1') { + int rc = kmem_cache_shrink(s); + + if (rc) + return rc; + } else + return -EINVAL; + return length; +} +SLAB_ATTR(shrink); + +static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf) +{ + if (!(s->flags & SLAB_STORE_USER)) + return -ENOSYS; + return list_locations(s, buf, TRACK_ALLOC); +} +SLAB_ATTR_RO(alloc_calls); + +static ssize_t free_calls_show(struct kmem_cache *s, char *buf) +{ + if (!(s->flags & SLAB_STORE_USER)) + return -ENOSYS; + return list_locations(s, buf, TRACK_FREE); +} +SLAB_ATTR_RO(free_calls); + +#ifdef CONFIG_NUMA +static ssize_t remote_node_defrag_ratio_show(struct kmem_cache *s, char *buf) +{ + return sprintf(buf, "%d\n", s->remote_node_defrag_ratio / 10); +} + +static ssize_t remote_node_defrag_ratio_store(struct kmem_cache *s, + const char *buf, size_t length) +{ + unsigned long ratio; + int err; + + err = strict_strtoul(buf, 10, &ratio); + if (err) + return err; + + if (ratio <= 100) + s->remote_node_defrag_ratio = ratio * 10; + + return length; +} +SLAB_ATTR(remote_node_defrag_ratio); +#endif + +#ifdef CONFIG_SLUB_STATS +static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si) +{ + unsigned long sum = 0; + int cpu; + int len; + int *data = kmalloc(nr_cpu_ids * sizeof(int), GFP_KERNEL); + + if (!data) + return -ENOMEM; + + for_each_online_cpu(cpu) { + unsigned x = get_cpu_slab(s, cpu)->stat[si]; + + data[cpu] = x; + sum += x; + } + + len = sprintf(buf, "%lu", sum); + +#ifdef CONFIG_SMP + for_each_online_cpu(cpu) { + if (data[cpu] && len < PAGE_SIZE - 20) + len += sprintf(buf + len, " C%d=%u", cpu, data[cpu]); + } +#endif + kfree(data); + return len + sprintf(buf + len, "\n"); +} + +#define STAT_ATTR(si, text) \ +static ssize_t text##_show(struct kmem_cache *s, char *buf) \ +{ \ + return show_stat(s, buf, si); \ +} \ +SLAB_ATTR_RO(text); \ + +STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath); +STAT_ATTR(ALLOC_SLOWPATH, alloc_slowpath); +STAT_ATTR(FREE_FASTPATH, free_fastpath); +STAT_ATTR(FREE_SLOWPATH, free_slowpath); +STAT_ATTR(FREE_FROZEN, free_frozen); +STAT_ATTR(FREE_ADD_PARTIAL, free_add_partial); +STAT_ATTR(FREE_REMOVE_PARTIAL, free_remove_partial); +STAT_ATTR(ALLOC_FROM_PARTIAL, alloc_from_partial); +STAT_ATTR(ALLOC_SLAB, alloc_slab); +STAT_ATTR(ALLOC_REFILL, alloc_refill); +STAT_ATTR(FREE_SLAB, free_slab); +STAT_ATTR(CPUSLAB_FLUSH, cpuslab_flush); +STAT_ATTR(DEACTIVATE_FULL, deactivate_full); +STAT_ATTR(DEACTIVATE_EMPTY, deactivate_empty); +STAT_ATTR(DEACTIVATE_TO_HEAD, deactivate_to_head); +STAT_ATTR(DEACTIVATE_TO_TAIL, deactivate_to_tail); +STAT_ATTR(DEACTIVATE_REMOTE_FREES, deactivate_remote_frees); +STAT_ATTR(ORDER_FALLBACK, order_fallback); +#endif + +static struct attribute *slab_attrs[] = { + &slab_size_attr.attr, + &object_size_attr.attr, + &objs_per_slab_attr.attr, + &order_attr.attr, + &objects_attr.attr, + &objects_partial_attr.attr, + &total_objects_attr.attr, + &slabs_attr.attr, + &partial_attr.attr, + &cpu_slabs_attr.attr, + &ctor_attr.attr, + &aliases_attr.attr, + &align_attr.attr, + &sanity_checks_attr.attr, + &trace_attr.attr, + &hwcache_align_attr.attr, + &reclaim_account_attr.attr, + &destroy_by_rcu_attr.attr, + &red_zone_attr.attr, + &poison_attr.attr, + &store_user_attr.attr, + &validate_attr.attr, + &shrink_attr.attr, + &alloc_calls_attr.attr, + &free_calls_attr.attr, +#ifdef CONFIG_ZONE_DMA + &cache_dma_attr.attr, +#endif +#ifdef CONFIG_NUMA + &remote_node_defrag_ratio_attr.attr, +#endif +#ifdef CONFIG_SLUB_STATS + &alloc_fastpath_attr.attr, + &alloc_slowpath_attr.attr, + &free_fastpath_attr.attr, + &free_slowpath_attr.attr, + &free_frozen_attr.attr, + &free_add_partial_attr.attr, + &free_remove_partial_attr.attr, + &alloc_from_partial_attr.attr, + &alloc_slab_attr.attr, + &alloc_refill_attr.attr, + &free_slab_attr.attr, + &cpuslab_flush_attr.attr, + &deactivate_full_attr.attr, + &deactivate_empty_attr.attr, + &deactivate_to_head_attr.attr, + &deactivate_to_tail_attr.attr, + &deactivate_remote_frees_attr.attr, + &order_fallback_attr.attr, +#endif + NULL +}; + +static struct attribute_group slab_attr_group = { + .attrs = slab_attrs, +}; + +static ssize_t slab_attr_show(struct kobject *kobj, + struct attribute *attr, + char *buf) +{ + struct slab_attribute *attribute; + struct kmem_cache *s; + int err; + + attribute = to_slab_attr(attr); + s = to_slab(kobj); + + if (!attribute->show) + return -EIO; + + err = attribute->show(s, buf); + + return err; +} + +static ssize_t slab_attr_store(struct kobject *kobj, + struct attribute *attr, + const char *buf, size_t len) +{ + struct slab_attribute *attribute; + struct kmem_cache *s; + int err; + + attribute = to_slab_attr(attr); + s = to_slab(kobj); + + if (!attribute->store) + return -EIO; + + err = attribute->store(s, buf, len); + + return err; +} + +static void kmem_cache_release(struct kobject *kobj) +{ + struct kmem_cache *s = to_slab(kobj); + + kfree(s); +} + +static struct sysfs_ops slab_sysfs_ops = { + .show = slab_attr_show, + .store = slab_attr_store, +}; + +static struct kobj_type slab_ktype = { + .sysfs_ops = &slab_sysfs_ops, + .release = kmem_cache_release +}; + +static int uevent_filter(struct kset *kset, struct kobject *kobj) +{ + struct kobj_type *ktype = get_ktype(kobj); + + if (ktype == &slab_ktype) + return 1; + return 0; +} + +static struct kset_uevent_ops slab_uevent_ops = { + .filter = uevent_filter, +}; + +static struct kset *slab_kset; + +#define ID_STR_LENGTH 64 + +/* Create a unique string id for a slab cache: + * + * Format :[flags-]size + */ +static char *create_unique_id(struct kmem_cache *s) +{ + char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL); + char *p = name; + + BUG_ON(!name); + + *p++ = ':'; + /* + * First flags affecting slabcache operations. We will only + * get here for aliasable slabs so we do not need to support + * too many flags. The flags here must cover all flags that + * are matched during merging to guarantee that the id is + * unique. + */ + if (s->flags & SLAB_CACHE_DMA) + *p++ = 'd'; + if (s->flags & SLAB_RECLAIM_ACCOUNT) + *p++ = 'a'; + if (s->flags & SLAB_DEBUG_FREE) + *p++ = 'F'; + if (p != name + 1) + *p++ = '-'; + p += sprintf(p, "%07d", s->size); + BUG_ON(p > name + ID_STR_LENGTH - 1); + return name; +} + +static int sysfs_slab_add(struct kmem_cache *s) +{ + int err; + const char *name; + int unmergeable; + + if (slab_state < SYSFS) + /* Defer until later */ + return 0; + + unmergeable = slab_unmergeable(s); + if (unmergeable) { + /* + * Slabcache can never be merged so we can use the name proper. + * This is typically the case for debug situations. In that + * case we can catch duplicate names easily. + */ + sysfs_remove_link(&slab_kset->kobj, s->name); + name = s->name; + } else { + /* + * Create a unique name for the slab as a target + * for the symlinks. + */ + name = create_unique_id(s); + } + + s->kobj.kset = slab_kset; + err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, name); + if (err) { + kobject_put(&s->kobj); + return err; + } + + err = sysfs_create_group(&s->kobj, &slab_attr_group); + if (err) + return err; + kobject_uevent(&s->kobj, KOBJ_ADD); + if (!unmergeable) { + /* Setup first alias */ + sysfs_slab_alias(s, s->name); + kfree(name); + } + return 0; +} + +static void sysfs_slab_remove(struct kmem_cache *s) +{ + kobject_uevent(&s->kobj, KOBJ_REMOVE); + kobject_del(&s->kobj); + kobject_put(&s->kobj); +} + +/* + * Need to buffer aliases during bootup until sysfs becomes + * available lest we loose that information. + */ +struct saved_alias { + struct kmem_cache *s; + const char *name; + struct saved_alias *next; +}; + +static struct saved_alias *alias_list; + +static int sysfs_slab_alias(struct kmem_cache *s, const char *name) +{ + struct saved_alias *al; + + if (slab_state == SYSFS) { + /* + * If we have a leftover link then remove it. + */ + sysfs_remove_link(&slab_kset->kobj, name); + return sysfs_create_link(&slab_kset->kobj, &s->kobj, name); + } + + al = kmalloc(sizeof(struct saved_alias), GFP_KERNEL); + if (!al) + return -ENOMEM; + + al->s = s; + al->name = name; + al->next = alias_list; + alias_list = al; + return 0; +} + +static int __init slab_sysfs_init(void) +{ + struct kmem_cache *s; + int err; + + slab_kset = kset_create_and_add("slab", &slab_uevent_ops, kernel_kobj); + if (!slab_kset) { + printk(KERN_ERR "Cannot register slab subsystem.\n"); + return -ENOSYS; + } + + slab_state = SYSFS; + + list_for_each_entry(s, &slab_caches, list) { + err = sysfs_slab_add(s); + if (err) + printk(KERN_ERR "SLUB: Unable to add boot slab %s" + " to sysfs\n", s->name); + } + + while (alias_list) { + struct saved_alias *al = alias_list; + + alias_list = alias_list->next; + err = sysfs_slab_alias(al->s, al->name); + if (err) + printk(KERN_ERR "SLUB: Unable to add boot slab alias" + " %s to sysfs\n", s->name); + kfree(al); + } + + resiliency_test(); + return 0; +} + +__initcall(slab_sysfs_init); +#endif + +/* + * The /proc/slabinfo ABI + */ +#ifdef CONFIG_SLABINFO +static void print_slabinfo_header(struct seq_file *m) +{ + seq_puts(m, "slabinfo - version: 2.1\n"); + seq_puts(m, "# name <active_objs> <num_objs> <objsize> " + "<objperslab> <pagesperslab>"); + seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>"); + seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>"); + seq_putc(m, '\n'); +} + +static void *s_start(struct seq_file *m, loff_t *pos) +{ + loff_t n = *pos; + + down_read(&slub_lock); + if (!n) + print_slabinfo_header(m); + + return seq_list_start(&slab_caches, *pos); +} + +static void *s_next(struct seq_file *m, void *p, loff_t *pos) +{ + return seq_list_next(p, &slab_caches, pos); +} + +static void s_stop(struct seq_file *m, void *p) +{ + up_read(&slub_lock); +} + +static int s_show(struct seq_file *m, void *p) +{ + unsigned long nr_partials = 0; + unsigned long nr_slabs = 0; + unsigned long nr_inuse = 0; + unsigned long nr_objs = 0; + unsigned long nr_free = 0; + struct kmem_cache *s; + int node; + + s = list_entry(p, struct kmem_cache, list); + + for_each_online_node(node) { + struct kmem_cache_node *n = get_node(s, node); + + if (!n) + continue; + + nr_partials += n->nr_partial; + nr_slabs += atomic_long_read(&n->nr_slabs); + nr_objs += atomic_long_read(&n->total_objects); + nr_free += count_partial(n, count_free); + } + + nr_inuse = nr_objs - nr_free; + + seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", s->name, nr_inuse, + nr_objs, s->size, oo_objects(s->oo), + (1 << oo_order(s->oo))); + seq_printf(m, " : tunables %4u %4u %4u", 0, 0, 0); + seq_printf(m, " : slabdata %6lu %6lu %6lu", nr_slabs, nr_slabs, + 0UL); + seq_putc(m, '\n'); + return 0; +} + +static const struct seq_operations slabinfo_op = { + .start = s_start, + .next = s_next, + .stop = s_stop, + .show = s_show, +}; + +static int slabinfo_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &slabinfo_op); +} + +static const struct file_operations proc_slabinfo_operations = { + .open = slabinfo_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +static int __init slab_proc_init(void) +{ + proc_create("slabinfo",S_IWUSR|S_IRUGO,NULL,&proc_slabinfo_operations); + return 0; +} +module_init(slab_proc_init); +#endif /* CONFIG_SLABINFO */ |
