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Christoph Lameter81819f02007-05-06 14:49:36 -07001/*
2 * SLUB: A slab allocator that limits cache line use instead of queuing
3 * objects in per cpu and per node lists.
4 *
5 * The allocator synchronizes using per slab locks and only
6 * uses a centralized lock to manage a pool of partial slabs.
7 *
Christoph Lametercde53532008-07-04 09:59:22 -07008 * (C) 2007 SGI, Christoph Lameter
Christoph Lameter81819f02007-05-06 14:49:36 -07009 */
10
11#include <linux/mm.h>
12#include <linux/module.h>
13#include <linux/bit_spinlock.h>
14#include <linux/interrupt.h>
15#include <linux/bitops.h>
16#include <linux/slab.h>
17#include <linux/seq_file.h>
18#include <linux/cpu.h>
19#include <linux/cpuset.h>
20#include <linux/mempolicy.h>
21#include <linux/ctype.h>
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -070022#include <linux/debugobjects.h>
Christoph Lameter81819f02007-05-06 14:49:36 -070023#include <linux/kallsyms.h>
Yasunori Gotob9049e22007-10-21 16:41:37 -070024#include <linux/memory.h>
Roman Zippelf8bd2252008-05-01 04:34:31 -070025#include <linux/math64.h>
Christoph Lameter81819f02007-05-06 14:49:36 -070026
27/*
28 * Lock order:
29 * 1. slab_lock(page)
30 * 2. slab->list_lock
31 *
32 * The slab_lock protects operations on the object of a particular
33 * slab and its metadata in the page struct. If the slab lock
34 * has been taken then no allocations nor frees can be performed
35 * on the objects in the slab nor can the slab be added or removed
36 * from the partial or full lists since this would mean modifying
37 * the page_struct of the slab.
38 *
39 * The list_lock protects the partial and full list on each node and
40 * the partial slab counter. If taken then no new slabs may be added or
41 * removed from the lists nor make the number of partial slabs be modified.
42 * (Note that the total number of slabs is an atomic value that may be
43 * modified without taking the list lock).
44 *
45 * The list_lock is a centralized lock and thus we avoid taking it as
46 * much as possible. As long as SLUB does not have to handle partial
47 * slabs, operations can continue without any centralized lock. F.e.
48 * allocating a long series of objects that fill up slabs does not require
49 * the list lock.
50 *
51 * The lock order is sometimes inverted when we are trying to get a slab
52 * off a list. We take the list_lock and then look for a page on the list
53 * to use. While we do that objects in the slabs may be freed. We can
54 * only operate on the slab if we have also taken the slab_lock. So we use
55 * a slab_trylock() on the slab. If trylock was successful then no frees
56 * can occur anymore and we can use the slab for allocations etc. If the
57 * slab_trylock() does not succeed then frees are in progress in the slab and
58 * we must stay away from it for a while since we may cause a bouncing
59 * cacheline if we try to acquire the lock. So go onto the next slab.
60 * If all pages are busy then we may allocate a new slab instead of reusing
61 * a partial slab. A new slab has noone operating on it and thus there is
62 * no danger of cacheline contention.
63 *
64 * Interrupts are disabled during allocation and deallocation in order to
65 * make the slab allocator safe to use in the context of an irq. In addition
66 * interrupts are disabled to ensure that the processor does not change
67 * while handling per_cpu slabs, due to kernel preemption.
68 *
69 * SLUB assigns one slab for allocation to each processor.
70 * Allocations only occur from these slabs called cpu slabs.
71 *
Christoph Lameter672bba32007-05-09 02:32:39 -070072 * Slabs with free elements are kept on a partial list and during regular
73 * operations no list for full slabs is used. If an object in a full slab is
Christoph Lameter81819f02007-05-06 14:49:36 -070074 * freed then the slab will show up again on the partial lists.
Christoph Lameter672bba32007-05-09 02:32:39 -070075 * We track full slabs for debugging purposes though because otherwise we
76 * cannot scan all objects.
Christoph Lameter81819f02007-05-06 14:49:36 -070077 *
78 * Slabs are freed when they become empty. Teardown and setup is
79 * minimal so we rely on the page allocators per cpu caches for
80 * fast frees and allocs.
81 *
82 * Overloading of page flags that are otherwise used for LRU management.
83 *
Christoph Lameter4b6f0752007-05-16 22:10:53 -070084 * PageActive The slab is frozen and exempt from list processing.
85 * This means that the slab is dedicated to a purpose
86 * such as satisfying allocations for a specific
87 * processor. Objects may be freed in the slab while
88 * it is frozen but slab_free will then skip the usual
89 * list operations. It is up to the processor holding
90 * the slab to integrate the slab into the slab lists
91 * when the slab is no longer needed.
92 *
93 * One use of this flag is to mark slabs that are
94 * used for allocations. Then such a slab becomes a cpu
95 * slab. The cpu slab may be equipped with an additional
Christoph Lameterdfb4f092007-10-16 01:26:05 -070096 * freelist that allows lockless access to
Christoph Lameter894b8782007-05-10 03:15:16 -070097 * free objects in addition to the regular freelist
98 * that requires the slab lock.
Christoph Lameter81819f02007-05-06 14:49:36 -070099 *
100 * PageError Slab requires special handling due to debug
101 * options set. This moves slab handling out of
Christoph Lameter894b8782007-05-10 03:15:16 -0700102 * the fast path and disables lockless freelists.
Christoph Lameter81819f02007-05-06 14:49:36 -0700103 */
104
Christoph Lameter5577bd82007-05-16 22:10:56 -0700105#ifdef CONFIG_SLUB_DEBUG
Andy Whitcroft8a380822008-07-23 21:27:18 -0700106#define SLABDEBUG 1
Christoph Lameter5577bd82007-05-16 22:10:56 -0700107#else
108#define SLABDEBUG 0
109#endif
110
Christoph Lameter81819f02007-05-06 14:49:36 -0700111/*
112 * Issues still to be resolved:
113 *
Christoph Lameter81819f02007-05-06 14:49:36 -0700114 * - Support PAGE_ALLOC_DEBUG. Should be easy to do.
115 *
Christoph Lameter81819f02007-05-06 14:49:36 -0700116 * - Variable sizing of the per node arrays
117 */
118
119/* Enable to test recovery from slab corruption on boot */
120#undef SLUB_RESILIENCY_TEST
121
Christoph Lameter81819f02007-05-06 14:49:36 -0700122/*
Christoph Lameter2086d262007-05-06 14:49:46 -0700123 * Mininum number of partial slabs. These will be left on the partial
124 * lists even if they are empty. kmem_cache_shrink may reclaim them.
125 */
Christoph Lameter76be8952007-12-21 14:37:37 -0800126#define MIN_PARTIAL 5
Christoph Lametere95eed52007-05-06 14:49:44 -0700127
Christoph Lameter2086d262007-05-06 14:49:46 -0700128/*
129 * Maximum number of desirable partial slabs.
130 * The existence of more partial slabs makes kmem_cache_shrink
131 * sort the partial list by the number of objects in the.
132 */
133#define MAX_PARTIAL 10
134
Christoph Lameter81819f02007-05-06 14:49:36 -0700135#define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \
136 SLAB_POISON | SLAB_STORE_USER)
Christoph Lameter672bba32007-05-09 02:32:39 -0700137
Christoph Lameter81819f02007-05-06 14:49:36 -0700138/*
139 * Set of flags that will prevent slab merging
140 */
141#define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
142 SLAB_TRACE | SLAB_DESTROY_BY_RCU)
143
144#define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \
145 SLAB_CACHE_DMA)
146
147#ifndef ARCH_KMALLOC_MINALIGN
Christoph Lameter47bfdc02007-05-06 14:49:37 -0700148#define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
Christoph Lameter81819f02007-05-06 14:49:36 -0700149#endif
150
151#ifndef ARCH_SLAB_MINALIGN
Christoph Lameter47bfdc02007-05-06 14:49:37 -0700152#define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
Christoph Lameter81819f02007-05-06 14:49:36 -0700153#endif
154
155/* Internal SLUB flags */
Christoph Lameter1ceef402007-08-07 15:11:48 -0700156#define __OBJECT_POISON 0x80000000 /* Poison object */
157#define __SYSFS_ADD_DEFERRED 0x40000000 /* Not yet visible via sysfs */
Christoph Lameter81819f02007-05-06 14:49:36 -0700158
159static int kmem_size = sizeof(struct kmem_cache);
160
161#ifdef CONFIG_SMP
162static struct notifier_block slab_notifier;
163#endif
164
165static enum {
166 DOWN, /* No slab functionality available */
167 PARTIAL, /* kmem_cache_open() works but kmalloc does not */
Christoph Lameter672bba32007-05-09 02:32:39 -0700168 UP, /* Everything works but does not show up in sysfs */
Christoph Lameter81819f02007-05-06 14:49:36 -0700169 SYSFS /* Sysfs up */
170} slab_state = DOWN;
171
172/* A list of all slab caches on the system */
173static DECLARE_RWSEM(slub_lock);
Adrian Bunk5af328a2007-07-17 04:03:27 -0700174static LIST_HEAD(slab_caches);
Christoph Lameter81819f02007-05-06 14:49:36 -0700175
Christoph Lameter02cbc872007-05-09 02:32:43 -0700176/*
177 * Tracking user of a slab.
178 */
179struct track {
180 void *addr; /* Called from address */
181 int cpu; /* Was running on cpu */
182 int pid; /* Pid context */
183 unsigned long when; /* When did the operation occur */
184};
185
186enum track_item { TRACK_ALLOC, TRACK_FREE };
187
Christoph Lameterf6acb632008-04-29 16:16:06 -0700188#ifdef CONFIG_SLUB_DEBUG
Christoph Lameter81819f02007-05-06 14:49:36 -0700189static int sysfs_slab_add(struct kmem_cache *);
190static int sysfs_slab_alias(struct kmem_cache *, const char *);
191static void sysfs_slab_remove(struct kmem_cache *);
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800192
Christoph Lameter81819f02007-05-06 14:49:36 -0700193#else
Christoph Lameter0c710012007-07-17 04:03:24 -0700194static inline int sysfs_slab_add(struct kmem_cache *s) { return 0; }
195static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p)
196 { return 0; }
Christoph Lameter151c6022008-01-07 22:29:05 -0800197static inline void sysfs_slab_remove(struct kmem_cache *s)
198{
199 kfree(s);
200}
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800201
Christoph Lameter81819f02007-05-06 14:49:36 -0700202#endif
203
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800204static inline void stat(struct kmem_cache_cpu *c, enum stat_item si)
205{
206#ifdef CONFIG_SLUB_STATS
207 c->stat[si]++;
208#endif
209}
210
Christoph Lameter81819f02007-05-06 14:49:36 -0700211/********************************************************************
212 * Core slab cache functions
213 *******************************************************************/
214
215int slab_is_available(void)
216{
217 return slab_state >= UP;
218}
219
220static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
221{
222#ifdef CONFIG_NUMA
223 return s->node[node];
224#else
225 return &s->local_node;
226#endif
227}
228
Christoph Lameterdfb4f092007-10-16 01:26:05 -0700229static inline struct kmem_cache_cpu *get_cpu_slab(struct kmem_cache *s, int cpu)
230{
Christoph Lameter4c93c3552007-10-16 01:26:08 -0700231#ifdef CONFIG_SMP
232 return s->cpu_slab[cpu];
233#else
234 return &s->cpu_slab;
235#endif
Christoph Lameterdfb4f092007-10-16 01:26:05 -0700236}
237
Christoph Lameter6446faa2008-02-15 23:45:26 -0800238/* Verify that a pointer has an address that is valid within a slab page */
Christoph Lameter02cbc872007-05-09 02:32:43 -0700239static inline int check_valid_pointer(struct kmem_cache *s,
240 struct page *page, const void *object)
241{
242 void *base;
243
Christoph Lametera973e9d2008-03-01 13:40:44 -0800244 if (!object)
Christoph Lameter02cbc872007-05-09 02:32:43 -0700245 return 1;
246
Christoph Lametera973e9d2008-03-01 13:40:44 -0800247 base = page_address(page);
Christoph Lameter39b26462008-04-14 19:11:30 +0300248 if (object < base || object >= base + page->objects * s->size ||
Christoph Lameter02cbc872007-05-09 02:32:43 -0700249 (object - base) % s->size) {
250 return 0;
251 }
252
253 return 1;
254}
255
Christoph Lameter81819f02007-05-06 14:49:36 -0700256/*
Christoph Lameter7656c722007-05-09 02:32:40 -0700257 * Slow version of get and set free pointer.
258 *
259 * This version requires touching the cache lines of kmem_cache which
260 * we avoid to do in the fast alloc free paths. There we obtain the offset
261 * from the page struct.
262 */
263static inline void *get_freepointer(struct kmem_cache *s, void *object)
264{
265 return *(void **)(object + s->offset);
266}
267
268static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
269{
270 *(void **)(object + s->offset) = fp;
271}
272
273/* Loop over all objects in a slab */
Christoph Lameter224a88b2008-04-14 19:11:31 +0300274#define for_each_object(__p, __s, __addr, __objects) \
275 for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\
Christoph Lameter7656c722007-05-09 02:32:40 -0700276 __p += (__s)->size)
277
278/* Scan freelist */
279#define for_each_free_object(__p, __s, __free) \
Christoph Lametera973e9d2008-03-01 13:40:44 -0800280 for (__p = (__free); __p; __p = get_freepointer((__s), __p))
Christoph Lameter7656c722007-05-09 02:32:40 -0700281
282/* Determine object index from a given position */
283static inline int slab_index(void *p, struct kmem_cache *s, void *addr)
284{
285 return (p - addr) / s->size;
286}
287
Christoph Lameter834f3d12008-04-14 19:11:31 +0300288static inline struct kmem_cache_order_objects oo_make(int order,
289 unsigned long size)
290{
291 struct kmem_cache_order_objects x = {
292 (order << 16) + (PAGE_SIZE << order) / size
293 };
294
295 return x;
296}
297
298static inline int oo_order(struct kmem_cache_order_objects x)
299{
300 return x.x >> 16;
301}
302
303static inline int oo_objects(struct kmem_cache_order_objects x)
304{
305 return x.x & ((1 << 16) - 1);
306}
307
Christoph Lameter41ecc552007-05-09 02:32:44 -0700308#ifdef CONFIG_SLUB_DEBUG
309/*
310 * Debug settings:
311 */
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700312#ifdef CONFIG_SLUB_DEBUG_ON
313static int slub_debug = DEBUG_DEFAULT_FLAGS;
314#else
Christoph Lameter41ecc552007-05-09 02:32:44 -0700315static int slub_debug;
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700316#endif
Christoph Lameter41ecc552007-05-09 02:32:44 -0700317
318static char *slub_debug_slabs;
319
Christoph Lameter7656c722007-05-09 02:32:40 -0700320/*
Christoph Lameter81819f02007-05-06 14:49:36 -0700321 * Object debugging
322 */
323static void print_section(char *text, u8 *addr, unsigned int length)
324{
325 int i, offset;
326 int newline = 1;
327 char ascii[17];
328
329 ascii[16] = 0;
330
331 for (i = 0; i < length; i++) {
332 if (newline) {
Christoph Lameter24922682007-07-17 04:03:18 -0700333 printk(KERN_ERR "%8s 0x%p: ", text, addr + i);
Christoph Lameter81819f02007-05-06 14:49:36 -0700334 newline = 0;
335 }
Pekka Enberg06428782008-01-07 23:20:27 -0800336 printk(KERN_CONT " %02x", addr[i]);
Christoph Lameter81819f02007-05-06 14:49:36 -0700337 offset = i % 16;
338 ascii[offset] = isgraph(addr[i]) ? addr[i] : '.';
339 if (offset == 15) {
Pekka Enberg06428782008-01-07 23:20:27 -0800340 printk(KERN_CONT " %s\n", ascii);
Christoph Lameter81819f02007-05-06 14:49:36 -0700341 newline = 1;
342 }
343 }
344 if (!newline) {
345 i %= 16;
346 while (i < 16) {
Pekka Enberg06428782008-01-07 23:20:27 -0800347 printk(KERN_CONT " ");
Christoph Lameter81819f02007-05-06 14:49:36 -0700348 ascii[i] = ' ';
349 i++;
350 }
Pekka Enberg06428782008-01-07 23:20:27 -0800351 printk(KERN_CONT " %s\n", ascii);
Christoph Lameter81819f02007-05-06 14:49:36 -0700352 }
353}
354
Christoph Lameter81819f02007-05-06 14:49:36 -0700355static struct track *get_track(struct kmem_cache *s, void *object,
356 enum track_item alloc)
357{
358 struct track *p;
359
360 if (s->offset)
361 p = object + s->offset + sizeof(void *);
362 else
363 p = object + s->inuse;
364
365 return p + alloc;
366}
367
368static void set_track(struct kmem_cache *s, void *object,
369 enum track_item alloc, void *addr)
370{
371 struct track *p;
372
373 if (s->offset)
374 p = object + s->offset + sizeof(void *);
375 else
376 p = object + s->inuse;
377
378 p += alloc;
379 if (addr) {
380 p->addr = addr;
381 p->cpu = smp_processor_id();
Alexey Dobriyan88e4ccf2008-06-23 02:58:37 +0400382 p->pid = current->pid;
Christoph Lameter81819f02007-05-06 14:49:36 -0700383 p->when = jiffies;
384 } else
385 memset(p, 0, sizeof(struct track));
386}
387
Christoph Lameter81819f02007-05-06 14:49:36 -0700388static void init_tracking(struct kmem_cache *s, void *object)
389{
Christoph Lameter24922682007-07-17 04:03:18 -0700390 if (!(s->flags & SLAB_STORE_USER))
391 return;
392
393 set_track(s, object, TRACK_FREE, NULL);
394 set_track(s, object, TRACK_ALLOC, NULL);
Christoph Lameter81819f02007-05-06 14:49:36 -0700395}
396
397static void print_track(const char *s, struct track *t)
398{
399 if (!t->addr)
400 return;
401
Linus Torvalds7daf7052008-07-14 12:12:53 -0700402 printk(KERN_ERR "INFO: %s in %pS age=%lu cpu=%u pid=%d\n",
403 s, t->addr, jiffies - t->when, t->cpu, t->pid);
Christoph Lameter81819f02007-05-06 14:49:36 -0700404}
405
Christoph Lameter24922682007-07-17 04:03:18 -0700406static void print_tracking(struct kmem_cache *s, void *object)
407{
408 if (!(s->flags & SLAB_STORE_USER))
409 return;
410
411 print_track("Allocated", get_track(s, object, TRACK_ALLOC));
412 print_track("Freed", get_track(s, object, TRACK_FREE));
413}
414
415static void print_page_info(struct page *page)
416{
Christoph Lameter39b26462008-04-14 19:11:30 +0300417 printk(KERN_ERR "INFO: Slab 0x%p objects=%u used=%u fp=0x%p flags=0x%04lx\n",
418 page, page->objects, page->inuse, page->freelist, page->flags);
Christoph Lameter24922682007-07-17 04:03:18 -0700419
420}
421
422static void slab_bug(struct kmem_cache *s, char *fmt, ...)
423{
424 va_list args;
425 char buf[100];
426
427 va_start(args, fmt);
428 vsnprintf(buf, sizeof(buf), fmt, args);
429 va_end(args);
430 printk(KERN_ERR "========================================"
431 "=====================================\n");
432 printk(KERN_ERR "BUG %s: %s\n", s->name, buf);
433 printk(KERN_ERR "----------------------------------------"
434 "-------------------------------------\n\n");
435}
436
437static void slab_fix(struct kmem_cache *s, char *fmt, ...)
438{
439 va_list args;
440 char buf[100];
441
442 va_start(args, fmt);
443 vsnprintf(buf, sizeof(buf), fmt, args);
444 va_end(args);
445 printk(KERN_ERR "FIX %s: %s\n", s->name, buf);
446}
447
448static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p)
Christoph Lameter81819f02007-05-06 14:49:36 -0700449{
450 unsigned int off; /* Offset of last byte */
Christoph Lametera973e9d2008-03-01 13:40:44 -0800451 u8 *addr = page_address(page);
Christoph Lameter24922682007-07-17 04:03:18 -0700452
453 print_tracking(s, p);
454
455 print_page_info(page);
456
457 printk(KERN_ERR "INFO: Object 0x%p @offset=%tu fp=0x%p\n\n",
458 p, p - addr, get_freepointer(s, p));
459
460 if (p > addr + 16)
461 print_section("Bytes b4", p - 16, 16);
462
Pekka Enberg0ebd6522008-07-19 14:17:22 +0300463 print_section("Object", p, min_t(unsigned long, s->objsize, PAGE_SIZE));
Christoph Lameter81819f02007-05-06 14:49:36 -0700464
465 if (s->flags & SLAB_RED_ZONE)
466 print_section("Redzone", p + s->objsize,
467 s->inuse - s->objsize);
468
Christoph Lameter81819f02007-05-06 14:49:36 -0700469 if (s->offset)
470 off = s->offset + sizeof(void *);
471 else
472 off = s->inuse;
473
Christoph Lameter24922682007-07-17 04:03:18 -0700474 if (s->flags & SLAB_STORE_USER)
Christoph Lameter81819f02007-05-06 14:49:36 -0700475 off += 2 * sizeof(struct track);
Christoph Lameter81819f02007-05-06 14:49:36 -0700476
477 if (off != s->size)
478 /* Beginning of the filler is the free pointer */
Christoph Lameter24922682007-07-17 04:03:18 -0700479 print_section("Padding", p + off, s->size - off);
480
481 dump_stack();
Christoph Lameter81819f02007-05-06 14:49:36 -0700482}
483
484static void object_err(struct kmem_cache *s, struct page *page,
485 u8 *object, char *reason)
486{
Christoph Lameter3dc50632008-04-23 12:28:01 -0700487 slab_bug(s, "%s", reason);
Christoph Lameter24922682007-07-17 04:03:18 -0700488 print_trailer(s, page, object);
Christoph Lameter81819f02007-05-06 14:49:36 -0700489}
490
Christoph Lameter24922682007-07-17 04:03:18 -0700491static void slab_err(struct kmem_cache *s, struct page *page, char *fmt, ...)
Christoph Lameter81819f02007-05-06 14:49:36 -0700492{
493 va_list args;
494 char buf[100];
495
Christoph Lameter24922682007-07-17 04:03:18 -0700496 va_start(args, fmt);
497 vsnprintf(buf, sizeof(buf), fmt, args);
Christoph Lameter81819f02007-05-06 14:49:36 -0700498 va_end(args);
Christoph Lameter3dc50632008-04-23 12:28:01 -0700499 slab_bug(s, "%s", buf);
Christoph Lameter24922682007-07-17 04:03:18 -0700500 print_page_info(page);
Christoph Lameter81819f02007-05-06 14:49:36 -0700501 dump_stack();
502}
503
504static void init_object(struct kmem_cache *s, void *object, int active)
505{
506 u8 *p = object;
507
508 if (s->flags & __OBJECT_POISON) {
509 memset(p, POISON_FREE, s->objsize - 1);
Pekka Enberg06428782008-01-07 23:20:27 -0800510 p[s->objsize - 1] = POISON_END;
Christoph Lameter81819f02007-05-06 14:49:36 -0700511 }
512
513 if (s->flags & SLAB_RED_ZONE)
514 memset(p + s->objsize,
515 active ? SLUB_RED_ACTIVE : SLUB_RED_INACTIVE,
516 s->inuse - s->objsize);
517}
518
Christoph Lameter24922682007-07-17 04:03:18 -0700519static u8 *check_bytes(u8 *start, unsigned int value, unsigned int bytes)
Christoph Lameter81819f02007-05-06 14:49:36 -0700520{
521 while (bytes) {
522 if (*start != (u8)value)
Christoph Lameter24922682007-07-17 04:03:18 -0700523 return start;
Christoph Lameter81819f02007-05-06 14:49:36 -0700524 start++;
525 bytes--;
526 }
Christoph Lameter24922682007-07-17 04:03:18 -0700527 return NULL;
528}
529
530static void restore_bytes(struct kmem_cache *s, char *message, u8 data,
531 void *from, void *to)
532{
533 slab_fix(s, "Restoring 0x%p-0x%p=0x%x\n", from, to - 1, data);
534 memset(from, data, to - from);
535}
536
537static int check_bytes_and_report(struct kmem_cache *s, struct page *page,
538 u8 *object, char *what,
Pekka Enberg06428782008-01-07 23:20:27 -0800539 u8 *start, unsigned int value, unsigned int bytes)
Christoph Lameter24922682007-07-17 04:03:18 -0700540{
541 u8 *fault;
542 u8 *end;
543
544 fault = check_bytes(start, value, bytes);
545 if (!fault)
546 return 1;
547
548 end = start + bytes;
549 while (end > fault && end[-1] == value)
550 end--;
551
552 slab_bug(s, "%s overwritten", what);
553 printk(KERN_ERR "INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n",
554 fault, end - 1, fault[0], value);
555 print_trailer(s, page, object);
556
557 restore_bytes(s, what, value, fault, end);
558 return 0;
Christoph Lameter81819f02007-05-06 14:49:36 -0700559}
560
Christoph Lameter81819f02007-05-06 14:49:36 -0700561/*
562 * Object layout:
563 *
564 * object address
565 * Bytes of the object to be managed.
566 * If the freepointer may overlay the object then the free
567 * pointer is the first word of the object.
Christoph Lameter672bba32007-05-09 02:32:39 -0700568 *
Christoph Lameter81819f02007-05-06 14:49:36 -0700569 * Poisoning uses 0x6b (POISON_FREE) and the last byte is
570 * 0xa5 (POISON_END)
571 *
572 * object + s->objsize
573 * Padding to reach word boundary. This is also used for Redzoning.
Christoph Lameter672bba32007-05-09 02:32:39 -0700574 * Padding is extended by another word if Redzoning is enabled and
575 * objsize == inuse.
576 *
Christoph Lameter81819f02007-05-06 14:49:36 -0700577 * We fill with 0xbb (RED_INACTIVE) for inactive objects and with
578 * 0xcc (RED_ACTIVE) for objects in use.
579 *
580 * object + s->inuse
Christoph Lameter672bba32007-05-09 02:32:39 -0700581 * Meta data starts here.
582 *
Christoph Lameter81819f02007-05-06 14:49:36 -0700583 * A. Free pointer (if we cannot overwrite object on free)
584 * B. Tracking data for SLAB_STORE_USER
Christoph Lameter672bba32007-05-09 02:32:39 -0700585 * C. Padding to reach required alignment boundary or at mininum
Christoph Lameter6446faa2008-02-15 23:45:26 -0800586 * one word if debugging is on to be able to detect writes
Christoph Lameter672bba32007-05-09 02:32:39 -0700587 * before the word boundary.
588 *
589 * Padding is done using 0x5a (POISON_INUSE)
Christoph Lameter81819f02007-05-06 14:49:36 -0700590 *
591 * object + s->size
Christoph Lameter672bba32007-05-09 02:32:39 -0700592 * Nothing is used beyond s->size.
Christoph Lameter81819f02007-05-06 14:49:36 -0700593 *
Christoph Lameter672bba32007-05-09 02:32:39 -0700594 * If slabcaches are merged then the objsize and inuse boundaries are mostly
595 * ignored. And therefore no slab options that rely on these boundaries
Christoph Lameter81819f02007-05-06 14:49:36 -0700596 * may be used with merged slabcaches.
597 */
598
Christoph Lameter81819f02007-05-06 14:49:36 -0700599static int check_pad_bytes(struct kmem_cache *s, struct page *page, u8 *p)
600{
601 unsigned long off = s->inuse; /* The end of info */
602
603 if (s->offset)
604 /* Freepointer is placed after the object. */
605 off += sizeof(void *);
606
607 if (s->flags & SLAB_STORE_USER)
608 /* We also have user information there */
609 off += 2 * sizeof(struct track);
610
611 if (s->size == off)
612 return 1;
613
Christoph Lameter24922682007-07-17 04:03:18 -0700614 return check_bytes_and_report(s, page, p, "Object padding",
615 p + off, POISON_INUSE, s->size - off);
Christoph Lameter81819f02007-05-06 14:49:36 -0700616}
617
Christoph Lameter39b26462008-04-14 19:11:30 +0300618/* Check the pad bytes at the end of a slab page */
Christoph Lameter81819f02007-05-06 14:49:36 -0700619static int slab_pad_check(struct kmem_cache *s, struct page *page)
620{
Christoph Lameter24922682007-07-17 04:03:18 -0700621 u8 *start;
622 u8 *fault;
623 u8 *end;
624 int length;
625 int remainder;
Christoph Lameter81819f02007-05-06 14:49:36 -0700626
627 if (!(s->flags & SLAB_POISON))
628 return 1;
629
Christoph Lametera973e9d2008-03-01 13:40:44 -0800630 start = page_address(page);
Christoph Lameter834f3d12008-04-14 19:11:31 +0300631 length = (PAGE_SIZE << compound_order(page));
Christoph Lameter39b26462008-04-14 19:11:30 +0300632 end = start + length;
633 remainder = length % s->size;
Christoph Lameter81819f02007-05-06 14:49:36 -0700634 if (!remainder)
635 return 1;
636
Christoph Lameter39b26462008-04-14 19:11:30 +0300637 fault = check_bytes(end - remainder, POISON_INUSE, remainder);
Christoph Lameter24922682007-07-17 04:03:18 -0700638 if (!fault)
639 return 1;
640 while (end > fault && end[-1] == POISON_INUSE)
641 end--;
642
643 slab_err(s, page, "Padding overwritten. 0x%p-0x%p", fault, end - 1);
Christoph Lameter39b26462008-04-14 19:11:30 +0300644 print_section("Padding", end - remainder, remainder);
Christoph Lameter24922682007-07-17 04:03:18 -0700645
646 restore_bytes(s, "slab padding", POISON_INUSE, start, end);
647 return 0;
Christoph Lameter81819f02007-05-06 14:49:36 -0700648}
649
650static int check_object(struct kmem_cache *s, struct page *page,
651 void *object, int active)
652{
653 u8 *p = object;
654 u8 *endobject = object + s->objsize;
655
656 if (s->flags & SLAB_RED_ZONE) {
657 unsigned int red =
658 active ? SLUB_RED_ACTIVE : SLUB_RED_INACTIVE;
659
Christoph Lameter24922682007-07-17 04:03:18 -0700660 if (!check_bytes_and_report(s, page, object, "Redzone",
661 endobject, red, s->inuse - s->objsize))
Christoph Lameter81819f02007-05-06 14:49:36 -0700662 return 0;
Christoph Lameter81819f02007-05-06 14:49:36 -0700663 } else {
Ingo Molnar3adbefe2008-02-05 17:57:39 -0800664 if ((s->flags & SLAB_POISON) && s->objsize < s->inuse) {
665 check_bytes_and_report(s, page, p, "Alignment padding",
666 endobject, POISON_INUSE, s->inuse - s->objsize);
667 }
Christoph Lameter81819f02007-05-06 14:49:36 -0700668 }
669
670 if (s->flags & SLAB_POISON) {
671 if (!active && (s->flags & __OBJECT_POISON) &&
Christoph Lameter24922682007-07-17 04:03:18 -0700672 (!check_bytes_and_report(s, page, p, "Poison", p,
673 POISON_FREE, s->objsize - 1) ||
674 !check_bytes_and_report(s, page, p, "Poison",
Pekka Enberg06428782008-01-07 23:20:27 -0800675 p + s->objsize - 1, POISON_END, 1)))
Christoph Lameter81819f02007-05-06 14:49:36 -0700676 return 0;
Christoph Lameter81819f02007-05-06 14:49:36 -0700677 /*
678 * check_pad_bytes cleans up on its own.
679 */
680 check_pad_bytes(s, page, p);
681 }
682
683 if (!s->offset && active)
684 /*
685 * Object and freepointer overlap. Cannot check
686 * freepointer while object is allocated.
687 */
688 return 1;
689
690 /* Check free pointer validity */
691 if (!check_valid_pointer(s, page, get_freepointer(s, p))) {
692 object_err(s, page, p, "Freepointer corrupt");
693 /*
694 * No choice but to zap it and thus loose the remainder
695 * of the free objects in this slab. May cause
Christoph Lameter672bba32007-05-09 02:32:39 -0700696 * another error because the object count is now wrong.
Christoph Lameter81819f02007-05-06 14:49:36 -0700697 */
Christoph Lametera973e9d2008-03-01 13:40:44 -0800698 set_freepointer(s, p, NULL);
Christoph Lameter81819f02007-05-06 14:49:36 -0700699 return 0;
700 }
701 return 1;
702}
703
704static int check_slab(struct kmem_cache *s, struct page *page)
705{
Christoph Lameter39b26462008-04-14 19:11:30 +0300706 int maxobj;
707
Christoph Lameter81819f02007-05-06 14:49:36 -0700708 VM_BUG_ON(!irqs_disabled());
709
710 if (!PageSlab(page)) {
Christoph Lameter24922682007-07-17 04:03:18 -0700711 slab_err(s, page, "Not a valid slab page");
Christoph Lameter81819f02007-05-06 14:49:36 -0700712 return 0;
713 }
Christoph Lameter39b26462008-04-14 19:11:30 +0300714
715 maxobj = (PAGE_SIZE << compound_order(page)) / s->size;
716 if (page->objects > maxobj) {
717 slab_err(s, page, "objects %u > max %u",
718 s->name, page->objects, maxobj);
719 return 0;
720 }
721 if (page->inuse > page->objects) {
Christoph Lameter24922682007-07-17 04:03:18 -0700722 slab_err(s, page, "inuse %u > max %u",
Christoph Lameter39b26462008-04-14 19:11:30 +0300723 s->name, page->inuse, page->objects);
Christoph Lameter81819f02007-05-06 14:49:36 -0700724 return 0;
725 }
726 /* Slab_pad_check fixes things up after itself */
727 slab_pad_check(s, page);
728 return 1;
729}
730
731/*
Christoph Lameter672bba32007-05-09 02:32:39 -0700732 * Determine if a certain object on a page is on the freelist. Must hold the
733 * slab lock to guarantee that the chains are in a consistent state.
Christoph Lameter81819f02007-05-06 14:49:36 -0700734 */
735static int on_freelist(struct kmem_cache *s, struct page *page, void *search)
736{
737 int nr = 0;
738 void *fp = page->freelist;
739 void *object = NULL;
Christoph Lameter224a88b2008-04-14 19:11:31 +0300740 unsigned long max_objects;
Christoph Lameter81819f02007-05-06 14:49:36 -0700741
Christoph Lameter39b26462008-04-14 19:11:30 +0300742 while (fp && nr <= page->objects) {
Christoph Lameter81819f02007-05-06 14:49:36 -0700743 if (fp == search)
744 return 1;
745 if (!check_valid_pointer(s, page, fp)) {
746 if (object) {
747 object_err(s, page, object,
748 "Freechain corrupt");
Christoph Lametera973e9d2008-03-01 13:40:44 -0800749 set_freepointer(s, object, NULL);
Christoph Lameter81819f02007-05-06 14:49:36 -0700750 break;
751 } else {
Christoph Lameter24922682007-07-17 04:03:18 -0700752 slab_err(s, page, "Freepointer corrupt");
Christoph Lametera973e9d2008-03-01 13:40:44 -0800753 page->freelist = NULL;
Christoph Lameter39b26462008-04-14 19:11:30 +0300754 page->inuse = page->objects;
Christoph Lameter24922682007-07-17 04:03:18 -0700755 slab_fix(s, "Freelist cleared");
Christoph Lameter81819f02007-05-06 14:49:36 -0700756 return 0;
757 }
758 break;
759 }
760 object = fp;
761 fp = get_freepointer(s, object);
762 nr++;
763 }
764
Christoph Lameter224a88b2008-04-14 19:11:31 +0300765 max_objects = (PAGE_SIZE << compound_order(page)) / s->size;
766 if (max_objects > 65535)
767 max_objects = 65535;
768
769 if (page->objects != max_objects) {
770 slab_err(s, page, "Wrong number of objects. Found %d but "
771 "should be %d", page->objects, max_objects);
772 page->objects = max_objects;
773 slab_fix(s, "Number of objects adjusted.");
774 }
Christoph Lameter39b26462008-04-14 19:11:30 +0300775 if (page->inuse != page->objects - nr) {
Christoph Lameter70d71222007-05-06 14:49:47 -0700776 slab_err(s, page, "Wrong object count. Counter is %d but "
Christoph Lameter39b26462008-04-14 19:11:30 +0300777 "counted were %d", page->inuse, page->objects - nr);
778 page->inuse = page->objects - nr;
Christoph Lameter24922682007-07-17 04:03:18 -0700779 slab_fix(s, "Object count adjusted.");
Christoph Lameter81819f02007-05-06 14:49:36 -0700780 }
781 return search == NULL;
782}
783
Christoph Lameter0121c6192008-04-29 16:11:12 -0700784static void trace(struct kmem_cache *s, struct page *page, void *object,
785 int alloc)
Christoph Lameter3ec09742007-05-16 22:11:00 -0700786{
787 if (s->flags & SLAB_TRACE) {
788 printk(KERN_INFO "TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
789 s->name,
790 alloc ? "alloc" : "free",
791 object, page->inuse,
792 page->freelist);
793
794 if (!alloc)
795 print_section("Object", (void *)object, s->objsize);
796
797 dump_stack();
798 }
799}
800
Christoph Lameter643b1132007-05-06 14:49:42 -0700801/*
Christoph Lameter672bba32007-05-09 02:32:39 -0700802 * Tracking of fully allocated slabs for debugging purposes.
Christoph Lameter643b1132007-05-06 14:49:42 -0700803 */
Christoph Lametere95eed52007-05-06 14:49:44 -0700804static void add_full(struct kmem_cache_node *n, struct page *page)
Christoph Lameter643b1132007-05-06 14:49:42 -0700805{
Christoph Lameter643b1132007-05-06 14:49:42 -0700806 spin_lock(&n->list_lock);
807 list_add(&page->lru, &n->full);
808 spin_unlock(&n->list_lock);
809}
810
811static void remove_full(struct kmem_cache *s, struct page *page)
812{
813 struct kmem_cache_node *n;
814
815 if (!(s->flags & SLAB_STORE_USER))
816 return;
817
818 n = get_node(s, page_to_nid(page));
819
820 spin_lock(&n->list_lock);
821 list_del(&page->lru);
822 spin_unlock(&n->list_lock);
823}
824
Christoph Lameter0f389ec2008-04-14 18:53:02 +0300825/* Tracking of the number of slabs for debugging purposes */
826static inline unsigned long slabs_node(struct kmem_cache *s, int node)
827{
828 struct kmem_cache_node *n = get_node(s, node);
829
830 return atomic_long_read(&n->nr_slabs);
831}
832
Christoph Lameter205ab992008-04-14 19:11:40 +0300833static inline void inc_slabs_node(struct kmem_cache *s, int node, int objects)
Christoph Lameter0f389ec2008-04-14 18:53:02 +0300834{
835 struct kmem_cache_node *n = get_node(s, node);
836
837 /*
838 * May be called early in order to allocate a slab for the
839 * kmem_cache_node structure. Solve the chicken-egg
840 * dilemma by deferring the increment of the count during
841 * bootstrap (see early_kmem_cache_node_alloc).
842 */
Christoph Lameter205ab992008-04-14 19:11:40 +0300843 if (!NUMA_BUILD || n) {
Christoph Lameter0f389ec2008-04-14 18:53:02 +0300844 atomic_long_inc(&n->nr_slabs);
Christoph Lameter205ab992008-04-14 19:11:40 +0300845 atomic_long_add(objects, &n->total_objects);
846 }
Christoph Lameter0f389ec2008-04-14 18:53:02 +0300847}
Christoph Lameter205ab992008-04-14 19:11:40 +0300848static inline void dec_slabs_node(struct kmem_cache *s, int node, int objects)
Christoph Lameter0f389ec2008-04-14 18:53:02 +0300849{
850 struct kmem_cache_node *n = get_node(s, node);
851
852 atomic_long_dec(&n->nr_slabs);
Christoph Lameter205ab992008-04-14 19:11:40 +0300853 atomic_long_sub(objects, &n->total_objects);
Christoph Lameter0f389ec2008-04-14 18:53:02 +0300854}
855
856/* Object debug checks for alloc/free paths */
Christoph Lameter3ec09742007-05-16 22:11:00 -0700857static void setup_object_debug(struct kmem_cache *s, struct page *page,
858 void *object)
859{
860 if (!(s->flags & (SLAB_STORE_USER|SLAB_RED_ZONE|__OBJECT_POISON)))
861 return;
862
863 init_object(s, object, 0);
864 init_tracking(s, object);
865}
866
867static int alloc_debug_processing(struct kmem_cache *s, struct page *page,
868 void *object, void *addr)
Christoph Lameter81819f02007-05-06 14:49:36 -0700869{
870 if (!check_slab(s, page))
871 goto bad;
872
Christoph Lameterd692ef62008-02-15 23:45:24 -0800873 if (!on_freelist(s, page, object)) {
Christoph Lameter24922682007-07-17 04:03:18 -0700874 object_err(s, page, object, "Object already allocated");
Christoph Lameter70d71222007-05-06 14:49:47 -0700875 goto bad;
Christoph Lameter81819f02007-05-06 14:49:36 -0700876 }
877
878 if (!check_valid_pointer(s, page, object)) {
879 object_err(s, page, object, "Freelist Pointer check fails");
Christoph Lameter70d71222007-05-06 14:49:47 -0700880 goto bad;
Christoph Lameter81819f02007-05-06 14:49:36 -0700881 }
882
Christoph Lameterd692ef62008-02-15 23:45:24 -0800883 if (!check_object(s, page, object, 0))
Christoph Lameter81819f02007-05-06 14:49:36 -0700884 goto bad;
Christoph Lameter81819f02007-05-06 14:49:36 -0700885
Christoph Lameter3ec09742007-05-16 22:11:00 -0700886 /* Success perform special debug activities for allocs */
887 if (s->flags & SLAB_STORE_USER)
888 set_track(s, object, TRACK_ALLOC, addr);
889 trace(s, page, object, 1);
890 init_object(s, object, 1);
Christoph Lameter81819f02007-05-06 14:49:36 -0700891 return 1;
Christoph Lameter3ec09742007-05-16 22:11:00 -0700892
Christoph Lameter81819f02007-05-06 14:49:36 -0700893bad:
894 if (PageSlab(page)) {
895 /*
896 * If this is a slab page then lets do the best we can
897 * to avoid issues in the future. Marking all objects
Christoph Lameter672bba32007-05-09 02:32:39 -0700898 * as used avoids touching the remaining objects.
Christoph Lameter81819f02007-05-06 14:49:36 -0700899 */
Christoph Lameter24922682007-07-17 04:03:18 -0700900 slab_fix(s, "Marking all objects used");
Christoph Lameter39b26462008-04-14 19:11:30 +0300901 page->inuse = page->objects;
Christoph Lametera973e9d2008-03-01 13:40:44 -0800902 page->freelist = NULL;
Christoph Lameter81819f02007-05-06 14:49:36 -0700903 }
904 return 0;
905}
906
Christoph Lameter3ec09742007-05-16 22:11:00 -0700907static int free_debug_processing(struct kmem_cache *s, struct page *page,
908 void *object, void *addr)
Christoph Lameter81819f02007-05-06 14:49:36 -0700909{
910 if (!check_slab(s, page))
911 goto fail;
912
913 if (!check_valid_pointer(s, page, object)) {
Christoph Lameter70d71222007-05-06 14:49:47 -0700914 slab_err(s, page, "Invalid object pointer 0x%p", object);
Christoph Lameter81819f02007-05-06 14:49:36 -0700915 goto fail;
916 }
917
918 if (on_freelist(s, page, object)) {
Christoph Lameter24922682007-07-17 04:03:18 -0700919 object_err(s, page, object, "Object already free");
Christoph Lameter81819f02007-05-06 14:49:36 -0700920 goto fail;
921 }
922
923 if (!check_object(s, page, object, 1))
924 return 0;
925
926 if (unlikely(s != page->slab)) {
Ingo Molnar3adbefe2008-02-05 17:57:39 -0800927 if (!PageSlab(page)) {
Christoph Lameter70d71222007-05-06 14:49:47 -0700928 slab_err(s, page, "Attempt to free object(0x%p) "
929 "outside of slab", object);
Ingo Molnar3adbefe2008-02-05 17:57:39 -0800930 } else if (!page->slab) {
Christoph Lameter81819f02007-05-06 14:49:36 -0700931 printk(KERN_ERR
Christoph Lameter70d71222007-05-06 14:49:47 -0700932 "SLUB <none>: no slab for object 0x%p.\n",
Christoph Lameter81819f02007-05-06 14:49:36 -0700933 object);
Christoph Lameter70d71222007-05-06 14:49:47 -0700934 dump_stack();
Pekka Enberg06428782008-01-07 23:20:27 -0800935 } else
Christoph Lameter24922682007-07-17 04:03:18 -0700936 object_err(s, page, object,
937 "page slab pointer corrupt.");
Christoph Lameter81819f02007-05-06 14:49:36 -0700938 goto fail;
939 }
Christoph Lameter3ec09742007-05-16 22:11:00 -0700940
941 /* Special debug activities for freeing objects */
Andy Whitcroft8a380822008-07-23 21:27:18 -0700942 if (!PageSlubFrozen(page) && !page->freelist)
Christoph Lameter3ec09742007-05-16 22:11:00 -0700943 remove_full(s, page);
944 if (s->flags & SLAB_STORE_USER)
945 set_track(s, object, TRACK_FREE, addr);
946 trace(s, page, object, 0);
947 init_object(s, object, 0);
Christoph Lameter81819f02007-05-06 14:49:36 -0700948 return 1;
Christoph Lameter3ec09742007-05-16 22:11:00 -0700949
Christoph Lameter81819f02007-05-06 14:49:36 -0700950fail:
Christoph Lameter24922682007-07-17 04:03:18 -0700951 slab_fix(s, "Object at 0x%p not freed", object);
Christoph Lameter81819f02007-05-06 14:49:36 -0700952 return 0;
953}
954
Christoph Lameter41ecc552007-05-09 02:32:44 -0700955static int __init setup_slub_debug(char *str)
956{
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700957 slub_debug = DEBUG_DEFAULT_FLAGS;
958 if (*str++ != '=' || !*str)
959 /*
960 * No options specified. Switch on full debugging.
961 */
962 goto out;
Christoph Lameter41ecc552007-05-09 02:32:44 -0700963
964 if (*str == ',')
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700965 /*
966 * No options but restriction on slabs. This means full
967 * debugging for slabs matching a pattern.
968 */
969 goto check_slabs;
970
971 slub_debug = 0;
972 if (*str == '-')
973 /*
974 * Switch off all debugging measures.
975 */
976 goto out;
977
978 /*
979 * Determine which debug features should be switched on
980 */
Pekka Enberg06428782008-01-07 23:20:27 -0800981 for (; *str && *str != ','; str++) {
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700982 switch (tolower(*str)) {
983 case 'f':
984 slub_debug |= SLAB_DEBUG_FREE;
985 break;
986 case 'z':
987 slub_debug |= SLAB_RED_ZONE;
988 break;
989 case 'p':
990 slub_debug |= SLAB_POISON;
991 break;
992 case 'u':
993 slub_debug |= SLAB_STORE_USER;
994 break;
995 case 't':
996 slub_debug |= SLAB_TRACE;
997 break;
998 default:
999 printk(KERN_ERR "slub_debug option '%c' "
Pekka Enberg06428782008-01-07 23:20:27 -08001000 "unknown. skipped\n", *str);
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001001 }
1002 }
1003
1004check_slabs:
1005 if (*str == ',')
Christoph Lameter41ecc552007-05-09 02:32:44 -07001006 slub_debug_slabs = str + 1;
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001007out:
Christoph Lameter41ecc552007-05-09 02:32:44 -07001008 return 1;
1009}
1010
1011__setup("slub_debug", setup_slub_debug);
1012
Christoph Lameterba0268a2007-09-11 15:24:11 -07001013static unsigned long kmem_cache_flags(unsigned long objsize,
1014 unsigned long flags, const char *name,
Alexey Dobriyan51cc5062008-07-25 19:45:34 -07001015 void (*ctor)(void *))
Christoph Lameter41ecc552007-05-09 02:32:44 -07001016{
1017 /*
Christoph Lametere1533622008-02-15 23:45:24 -08001018 * Enable debugging if selected on the kernel commandline.
Christoph Lameter41ecc552007-05-09 02:32:44 -07001019 */
Christoph Lametere1533622008-02-15 23:45:24 -08001020 if (slub_debug && (!slub_debug_slabs ||
1021 strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs)) == 0))
1022 flags |= slub_debug;
Christoph Lameterba0268a2007-09-11 15:24:11 -07001023
1024 return flags;
Christoph Lameter41ecc552007-05-09 02:32:44 -07001025}
1026#else
Christoph Lameter3ec09742007-05-16 22:11:00 -07001027static inline void setup_object_debug(struct kmem_cache *s,
1028 struct page *page, void *object) {}
Christoph Lameter41ecc552007-05-09 02:32:44 -07001029
Christoph Lameter3ec09742007-05-16 22:11:00 -07001030static inline int alloc_debug_processing(struct kmem_cache *s,
1031 struct page *page, void *object, void *addr) { return 0; }
Christoph Lameter41ecc552007-05-09 02:32:44 -07001032
Christoph Lameter3ec09742007-05-16 22:11:00 -07001033static inline int free_debug_processing(struct kmem_cache *s,
1034 struct page *page, void *object, void *addr) { return 0; }
Christoph Lameter41ecc552007-05-09 02:32:44 -07001035
Christoph Lameter41ecc552007-05-09 02:32:44 -07001036static inline int slab_pad_check(struct kmem_cache *s, struct page *page)
1037 { return 1; }
1038static inline int check_object(struct kmem_cache *s, struct page *page,
1039 void *object, int active) { return 1; }
Christoph Lameter3ec09742007-05-16 22:11:00 -07001040static inline void add_full(struct kmem_cache_node *n, struct page *page) {}
Christoph Lameterba0268a2007-09-11 15:24:11 -07001041static inline unsigned long kmem_cache_flags(unsigned long objsize,
1042 unsigned long flags, const char *name,
Alexey Dobriyan51cc5062008-07-25 19:45:34 -07001043 void (*ctor)(void *))
Christoph Lameterba0268a2007-09-11 15:24:11 -07001044{
1045 return flags;
1046}
Christoph Lameter41ecc552007-05-09 02:32:44 -07001047#define slub_debug 0
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001048
1049static inline unsigned long slabs_node(struct kmem_cache *s, int node)
1050 { return 0; }
Christoph Lameter205ab992008-04-14 19:11:40 +03001051static inline void inc_slabs_node(struct kmem_cache *s, int node,
1052 int objects) {}
1053static inline void dec_slabs_node(struct kmem_cache *s, int node,
1054 int objects) {}
Christoph Lameter41ecc552007-05-09 02:32:44 -07001055#endif
Christoph Lameter205ab992008-04-14 19:11:40 +03001056
Christoph Lameter81819f02007-05-06 14:49:36 -07001057/*
1058 * Slab allocation and freeing
1059 */
Christoph Lameter65c33762008-04-14 19:11:40 +03001060static inline struct page *alloc_slab_page(gfp_t flags, int node,
1061 struct kmem_cache_order_objects oo)
1062{
1063 int order = oo_order(oo);
1064
1065 if (node == -1)
1066 return alloc_pages(flags, order);
1067 else
1068 return alloc_pages_node(node, flags, order);
1069}
1070
Christoph Lameter81819f02007-05-06 14:49:36 -07001071static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
1072{
Pekka Enberg06428782008-01-07 23:20:27 -08001073 struct page *page;
Christoph Lameter834f3d12008-04-14 19:11:31 +03001074 struct kmem_cache_order_objects oo = s->oo;
Christoph Lameter81819f02007-05-06 14:49:36 -07001075
Christoph Lameterb7a49f02008-02-14 14:21:32 -08001076 flags |= s->allocflags;
Mel Gormane12ba742007-10-16 01:25:52 -07001077
Christoph Lameter65c33762008-04-14 19:11:40 +03001078 page = alloc_slab_page(flags | __GFP_NOWARN | __GFP_NORETRY, node,
1079 oo);
1080 if (unlikely(!page)) {
1081 oo = s->min;
1082 /*
1083 * Allocation may have failed due to fragmentation.
1084 * Try a lower order alloc if possible
1085 */
1086 page = alloc_slab_page(flags, node, oo);
1087 if (!page)
1088 return NULL;
Christoph Lameter81819f02007-05-06 14:49:36 -07001089
Christoph Lameter65c33762008-04-14 19:11:40 +03001090 stat(get_cpu_slab(s, raw_smp_processor_id()), ORDER_FALLBACK);
1091 }
Christoph Lameter834f3d12008-04-14 19:11:31 +03001092 page->objects = oo_objects(oo);
Christoph Lameter81819f02007-05-06 14:49:36 -07001093 mod_zone_page_state(page_zone(page),
1094 (s->flags & SLAB_RECLAIM_ACCOUNT) ?
1095 NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
Christoph Lameter65c33762008-04-14 19:11:40 +03001096 1 << oo_order(oo));
Christoph Lameter81819f02007-05-06 14:49:36 -07001097
1098 return page;
1099}
1100
1101static void setup_object(struct kmem_cache *s, struct page *page,
1102 void *object)
1103{
Christoph Lameter3ec09742007-05-16 22:11:00 -07001104 setup_object_debug(s, page, object);
Christoph Lameter4f104932007-05-06 14:50:17 -07001105 if (unlikely(s->ctor))
Alexey Dobriyan51cc5062008-07-25 19:45:34 -07001106 s->ctor(object);
Christoph Lameter81819f02007-05-06 14:49:36 -07001107}
1108
1109static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
1110{
1111 struct page *page;
Christoph Lameter81819f02007-05-06 14:49:36 -07001112 void *start;
Christoph Lameter81819f02007-05-06 14:49:36 -07001113 void *last;
1114 void *p;
1115
Christoph Lameter6cb06222007-10-16 01:25:41 -07001116 BUG_ON(flags & GFP_SLAB_BUG_MASK);
Christoph Lameter81819f02007-05-06 14:49:36 -07001117
Christoph Lameter6cb06222007-10-16 01:25:41 -07001118 page = allocate_slab(s,
1119 flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node);
Christoph Lameter81819f02007-05-06 14:49:36 -07001120 if (!page)
1121 goto out;
1122
Christoph Lameter205ab992008-04-14 19:11:40 +03001123 inc_slabs_node(s, page_to_nid(page), page->objects);
Christoph Lameter81819f02007-05-06 14:49:36 -07001124 page->slab = s;
1125 page->flags |= 1 << PG_slab;
1126 if (s->flags & (SLAB_DEBUG_FREE | SLAB_RED_ZONE | SLAB_POISON |
1127 SLAB_STORE_USER | SLAB_TRACE))
Andy Whitcroft8a380822008-07-23 21:27:18 -07001128 __SetPageSlubDebug(page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001129
1130 start = page_address(page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001131
1132 if (unlikely(s->flags & SLAB_POISON))
Christoph Lameter834f3d12008-04-14 19:11:31 +03001133 memset(start, POISON_INUSE, PAGE_SIZE << compound_order(page));
Christoph Lameter81819f02007-05-06 14:49:36 -07001134
1135 last = start;
Christoph Lameter224a88b2008-04-14 19:11:31 +03001136 for_each_object(p, s, start, page->objects) {
Christoph Lameter81819f02007-05-06 14:49:36 -07001137 setup_object(s, page, last);
1138 set_freepointer(s, last, p);
1139 last = p;
1140 }
1141 setup_object(s, page, last);
Christoph Lametera973e9d2008-03-01 13:40:44 -08001142 set_freepointer(s, last, NULL);
Christoph Lameter81819f02007-05-06 14:49:36 -07001143
1144 page->freelist = start;
1145 page->inuse = 0;
1146out:
Christoph Lameter81819f02007-05-06 14:49:36 -07001147 return page;
1148}
1149
1150static void __free_slab(struct kmem_cache *s, struct page *page)
1151{
Christoph Lameter834f3d12008-04-14 19:11:31 +03001152 int order = compound_order(page);
1153 int pages = 1 << order;
Christoph Lameter81819f02007-05-06 14:49:36 -07001154
Andy Whitcroft8a380822008-07-23 21:27:18 -07001155 if (unlikely(SLABDEBUG && PageSlubDebug(page))) {
Christoph Lameter81819f02007-05-06 14:49:36 -07001156 void *p;
1157
1158 slab_pad_check(s, page);
Christoph Lameter224a88b2008-04-14 19:11:31 +03001159 for_each_object(p, s, page_address(page),
1160 page->objects)
Christoph Lameter81819f02007-05-06 14:49:36 -07001161 check_object(s, page, p, 0);
Andy Whitcroft8a380822008-07-23 21:27:18 -07001162 __ClearPageSlubDebug(page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001163 }
1164
1165 mod_zone_page_state(page_zone(page),
1166 (s->flags & SLAB_RECLAIM_ACCOUNT) ?
1167 NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
Pekka Enberg06428782008-01-07 23:20:27 -08001168 -pages);
Christoph Lameter81819f02007-05-06 14:49:36 -07001169
Christoph Lameter49bd5222008-04-14 18:52:18 +03001170 __ClearPageSlab(page);
1171 reset_page_mapcount(page);
Christoph Lameter834f3d12008-04-14 19:11:31 +03001172 __free_pages(page, order);
Christoph Lameter81819f02007-05-06 14:49:36 -07001173}
1174
1175static void rcu_free_slab(struct rcu_head *h)
1176{
1177 struct page *page;
1178
1179 page = container_of((struct list_head *)h, struct page, lru);
1180 __free_slab(page->slab, page);
1181}
1182
1183static void free_slab(struct kmem_cache *s, struct page *page)
1184{
1185 if (unlikely(s->flags & SLAB_DESTROY_BY_RCU)) {
1186 /*
1187 * RCU free overloads the RCU head over the LRU
1188 */
1189 struct rcu_head *head = (void *)&page->lru;
1190
1191 call_rcu(head, rcu_free_slab);
1192 } else
1193 __free_slab(s, page);
1194}
1195
1196static void discard_slab(struct kmem_cache *s, struct page *page)
1197{
Christoph Lameter205ab992008-04-14 19:11:40 +03001198 dec_slabs_node(s, page_to_nid(page), page->objects);
Christoph Lameter81819f02007-05-06 14:49:36 -07001199 free_slab(s, page);
1200}
1201
1202/*
1203 * Per slab locking using the pagelock
1204 */
1205static __always_inline void slab_lock(struct page *page)
1206{
1207 bit_spin_lock(PG_locked, &page->flags);
1208}
1209
1210static __always_inline void slab_unlock(struct page *page)
1211{
Nick Piggina76d3542008-01-07 23:20:27 -08001212 __bit_spin_unlock(PG_locked, &page->flags);
Christoph Lameter81819f02007-05-06 14:49:36 -07001213}
1214
1215static __always_inline int slab_trylock(struct page *page)
1216{
1217 int rc = 1;
1218
1219 rc = bit_spin_trylock(PG_locked, &page->flags);
1220 return rc;
1221}
1222
1223/*
1224 * Management of partially allocated slabs
1225 */
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001226static void add_partial(struct kmem_cache_node *n,
1227 struct page *page, int tail)
Christoph Lameter81819f02007-05-06 14:49:36 -07001228{
Christoph Lametere95eed52007-05-06 14:49:44 -07001229 spin_lock(&n->list_lock);
1230 n->nr_partial++;
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001231 if (tail)
1232 list_add_tail(&page->lru, &n->partial);
1233 else
1234 list_add(&page->lru, &n->partial);
Christoph Lameter81819f02007-05-06 14:49:36 -07001235 spin_unlock(&n->list_lock);
1236}
1237
Christoph Lameter0121c6192008-04-29 16:11:12 -07001238static void remove_partial(struct kmem_cache *s, struct page *page)
Christoph Lameter81819f02007-05-06 14:49:36 -07001239{
1240 struct kmem_cache_node *n = get_node(s, page_to_nid(page));
1241
1242 spin_lock(&n->list_lock);
1243 list_del(&page->lru);
1244 n->nr_partial--;
1245 spin_unlock(&n->list_lock);
1246}
1247
1248/*
Christoph Lameter672bba32007-05-09 02:32:39 -07001249 * Lock slab and remove from the partial list.
Christoph Lameter81819f02007-05-06 14:49:36 -07001250 *
Christoph Lameter672bba32007-05-09 02:32:39 -07001251 * Must hold list_lock.
Christoph Lameter81819f02007-05-06 14:49:36 -07001252 */
Christoph Lameter0121c6192008-04-29 16:11:12 -07001253static inline int lock_and_freeze_slab(struct kmem_cache_node *n,
1254 struct page *page)
Christoph Lameter81819f02007-05-06 14:49:36 -07001255{
1256 if (slab_trylock(page)) {
1257 list_del(&page->lru);
1258 n->nr_partial--;
Andy Whitcroft8a380822008-07-23 21:27:18 -07001259 __SetPageSlubFrozen(page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001260 return 1;
1261 }
1262 return 0;
1263}
1264
1265/*
Christoph Lameter672bba32007-05-09 02:32:39 -07001266 * Try to allocate a partial slab from a specific node.
Christoph Lameter81819f02007-05-06 14:49:36 -07001267 */
1268static struct page *get_partial_node(struct kmem_cache_node *n)
1269{
1270 struct page *page;
1271
1272 /*
1273 * Racy check. If we mistakenly see no partial slabs then we
1274 * just allocate an empty slab. If we mistakenly try to get a
Christoph Lameter672bba32007-05-09 02:32:39 -07001275 * partial slab and there is none available then get_partials()
1276 * will return NULL.
Christoph Lameter81819f02007-05-06 14:49:36 -07001277 */
1278 if (!n || !n->nr_partial)
1279 return NULL;
1280
1281 spin_lock(&n->list_lock);
1282 list_for_each_entry(page, &n->partial, lru)
Christoph Lameter4b6f0752007-05-16 22:10:53 -07001283 if (lock_and_freeze_slab(n, page))
Christoph Lameter81819f02007-05-06 14:49:36 -07001284 goto out;
1285 page = NULL;
1286out:
1287 spin_unlock(&n->list_lock);
1288 return page;
1289}
1290
1291/*
Christoph Lameter672bba32007-05-09 02:32:39 -07001292 * Get a page from somewhere. Search in increasing NUMA distances.
Christoph Lameter81819f02007-05-06 14:49:36 -07001293 */
1294static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags)
1295{
1296#ifdef CONFIG_NUMA
1297 struct zonelist *zonelist;
Mel Gormandd1a2392008-04-28 02:12:17 -07001298 struct zoneref *z;
Mel Gorman54a6eb52008-04-28 02:12:16 -07001299 struct zone *zone;
1300 enum zone_type high_zoneidx = gfp_zone(flags);
Christoph Lameter81819f02007-05-06 14:49:36 -07001301 struct page *page;
1302
1303 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07001304 * The defrag ratio allows a configuration of the tradeoffs between
1305 * inter node defragmentation and node local allocations. A lower
1306 * defrag_ratio increases the tendency to do local allocations
1307 * instead of attempting to obtain partial slabs from other nodes.
Christoph Lameter81819f02007-05-06 14:49:36 -07001308 *
Christoph Lameter672bba32007-05-09 02:32:39 -07001309 * If the defrag_ratio is set to 0 then kmalloc() always
1310 * returns node local objects. If the ratio is higher then kmalloc()
1311 * may return off node objects because partial slabs are obtained
1312 * from other nodes and filled up.
Christoph Lameter81819f02007-05-06 14:49:36 -07001313 *
Christoph Lameter6446faa2008-02-15 23:45:26 -08001314 * If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes
Christoph Lameter672bba32007-05-09 02:32:39 -07001315 * defrag_ratio = 1000) then every (well almost) allocation will
1316 * first attempt to defrag slab caches on other nodes. This means
1317 * scanning over all nodes to look for partial slabs which may be
1318 * expensive if we do it every time we are trying to find a slab
1319 * with available objects.
Christoph Lameter81819f02007-05-06 14:49:36 -07001320 */
Christoph Lameter98246012008-01-07 23:20:26 -08001321 if (!s->remote_node_defrag_ratio ||
1322 get_cycles() % 1024 > s->remote_node_defrag_ratio)
Christoph Lameter81819f02007-05-06 14:49:36 -07001323 return NULL;
1324
Mel Gorman0e884602008-04-28 02:12:14 -07001325 zonelist = node_zonelist(slab_node(current->mempolicy), flags);
Mel Gorman54a6eb52008-04-28 02:12:16 -07001326 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
Christoph Lameter81819f02007-05-06 14:49:36 -07001327 struct kmem_cache_node *n;
1328
Mel Gorman54a6eb52008-04-28 02:12:16 -07001329 n = get_node(s, zone_to_nid(zone));
Christoph Lameter81819f02007-05-06 14:49:36 -07001330
Mel Gorman54a6eb52008-04-28 02:12:16 -07001331 if (n && cpuset_zone_allowed_hardwall(zone, flags) &&
Pekka Enberg5595cff2008-08-05 09:28:47 +03001332 n->nr_partial > n->min_partial) {
Christoph Lameter81819f02007-05-06 14:49:36 -07001333 page = get_partial_node(n);
1334 if (page)
1335 return page;
1336 }
1337 }
1338#endif
1339 return NULL;
1340}
1341
1342/*
1343 * Get a partial page, lock it and return it.
1344 */
1345static struct page *get_partial(struct kmem_cache *s, gfp_t flags, int node)
1346{
1347 struct page *page;
1348 int searchnode = (node == -1) ? numa_node_id() : node;
1349
1350 page = get_partial_node(get_node(s, searchnode));
1351 if (page || (flags & __GFP_THISNODE))
1352 return page;
1353
1354 return get_any_partial(s, flags);
1355}
1356
1357/*
1358 * Move a page back to the lists.
1359 *
1360 * Must be called with the slab lock held.
1361 *
1362 * On exit the slab lock will have been dropped.
1363 */
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001364static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail)
Christoph Lameter81819f02007-05-06 14:49:36 -07001365{
Christoph Lametere95eed52007-05-06 14:49:44 -07001366 struct kmem_cache_node *n = get_node(s, page_to_nid(page));
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001367 struct kmem_cache_cpu *c = get_cpu_slab(s, smp_processor_id());
Christoph Lametere95eed52007-05-06 14:49:44 -07001368
Andy Whitcroft8a380822008-07-23 21:27:18 -07001369 __ClearPageSlubFrozen(page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001370 if (page->inuse) {
Christoph Lametere95eed52007-05-06 14:49:44 -07001371
Christoph Lametera973e9d2008-03-01 13:40:44 -08001372 if (page->freelist) {
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001373 add_partial(n, page, tail);
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001374 stat(c, tail ? DEACTIVATE_TO_TAIL : DEACTIVATE_TO_HEAD);
1375 } else {
1376 stat(c, DEACTIVATE_FULL);
Andy Whitcroft8a380822008-07-23 21:27:18 -07001377 if (SLABDEBUG && PageSlubDebug(page) &&
1378 (s->flags & SLAB_STORE_USER))
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001379 add_full(n, page);
1380 }
Christoph Lameter81819f02007-05-06 14:49:36 -07001381 slab_unlock(page);
1382 } else {
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001383 stat(c, DEACTIVATE_EMPTY);
Pekka Enberg5595cff2008-08-05 09:28:47 +03001384 if (n->nr_partial < n->min_partial) {
Christoph Lametere95eed52007-05-06 14:49:44 -07001385 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07001386 * Adding an empty slab to the partial slabs in order
1387 * to avoid page allocator overhead. This slab needs
1388 * to come after the other slabs with objects in
Christoph Lameter6446faa2008-02-15 23:45:26 -08001389 * so that the others get filled first. That way the
1390 * size of the partial list stays small.
1391 *
Christoph Lameter0121c6192008-04-29 16:11:12 -07001392 * kmem_cache_shrink can reclaim any empty slabs from
1393 * the partial list.
Christoph Lametere95eed52007-05-06 14:49:44 -07001394 */
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001395 add_partial(n, page, 1);
Christoph Lametere95eed52007-05-06 14:49:44 -07001396 slab_unlock(page);
1397 } else {
1398 slab_unlock(page);
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001399 stat(get_cpu_slab(s, raw_smp_processor_id()), FREE_SLAB);
Christoph Lametere95eed52007-05-06 14:49:44 -07001400 discard_slab(s, page);
1401 }
Christoph Lameter81819f02007-05-06 14:49:36 -07001402 }
1403}
1404
1405/*
1406 * Remove the cpu slab
1407 */
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001408static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
Christoph Lameter81819f02007-05-06 14:49:36 -07001409{
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001410 struct page *page = c->page;
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001411 int tail = 1;
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001412
Christoph Lameterb773ad72008-03-04 11:10:17 -08001413 if (page->freelist)
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001414 stat(c, DEACTIVATE_REMOTE_FREES);
Christoph Lameter894b8782007-05-10 03:15:16 -07001415 /*
Christoph Lameter6446faa2008-02-15 23:45:26 -08001416 * Merge cpu freelist into slab freelist. Typically we get here
Christoph Lameter894b8782007-05-10 03:15:16 -07001417 * because both freelists are empty. So this is unlikely
1418 * to occur.
1419 */
Christoph Lametera973e9d2008-03-01 13:40:44 -08001420 while (unlikely(c->freelist)) {
Christoph Lameter894b8782007-05-10 03:15:16 -07001421 void **object;
1422
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001423 tail = 0; /* Hot objects. Put the slab first */
1424
Christoph Lameter894b8782007-05-10 03:15:16 -07001425 /* Retrieve object from cpu_freelist */
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001426 object = c->freelist;
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001427 c->freelist = c->freelist[c->offset];
Christoph Lameter894b8782007-05-10 03:15:16 -07001428
1429 /* And put onto the regular freelist */
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001430 object[c->offset] = page->freelist;
Christoph Lameter894b8782007-05-10 03:15:16 -07001431 page->freelist = object;
1432 page->inuse--;
1433 }
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001434 c->page = NULL;
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001435 unfreeze_slab(s, page, tail);
Christoph Lameter81819f02007-05-06 14:49:36 -07001436}
1437
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001438static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
Christoph Lameter81819f02007-05-06 14:49:36 -07001439{
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001440 stat(c, CPUSLAB_FLUSH);
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001441 slab_lock(c->page);
1442 deactivate_slab(s, c);
Christoph Lameter81819f02007-05-06 14:49:36 -07001443}
1444
1445/*
1446 * Flush cpu slab.
Christoph Lameter6446faa2008-02-15 23:45:26 -08001447 *
Christoph Lameter81819f02007-05-06 14:49:36 -07001448 * Called from IPI handler with interrupts disabled.
1449 */
Christoph Lameter0c710012007-07-17 04:03:24 -07001450static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu)
Christoph Lameter81819f02007-05-06 14:49:36 -07001451{
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001452 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
Christoph Lameter81819f02007-05-06 14:49:36 -07001453
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001454 if (likely(c && c->page))
1455 flush_slab(s, c);
Christoph Lameter81819f02007-05-06 14:49:36 -07001456}
1457
1458static void flush_cpu_slab(void *d)
1459{
1460 struct kmem_cache *s = d;
Christoph Lameter81819f02007-05-06 14:49:36 -07001461
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001462 __flush_cpu_slab(s, smp_processor_id());
Christoph Lameter81819f02007-05-06 14:49:36 -07001463}
1464
1465static void flush_all(struct kmem_cache *s)
1466{
Jens Axboe15c8b6c2008-05-09 09:39:44 +02001467 on_each_cpu(flush_cpu_slab, s, 1);
Christoph Lameter81819f02007-05-06 14:49:36 -07001468}
1469
1470/*
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001471 * Check if the objects in a per cpu structure fit numa
1472 * locality expectations.
1473 */
1474static inline int node_match(struct kmem_cache_cpu *c, int node)
1475{
1476#ifdef CONFIG_NUMA
1477 if (node != -1 && c->node != node)
1478 return 0;
1479#endif
1480 return 1;
1481}
1482
1483/*
Christoph Lameter894b8782007-05-10 03:15:16 -07001484 * Slow path. The lockless freelist is empty or we need to perform
1485 * debugging duties.
Christoph Lameter81819f02007-05-06 14:49:36 -07001486 *
Christoph Lameter894b8782007-05-10 03:15:16 -07001487 * Interrupts are disabled.
Christoph Lameter81819f02007-05-06 14:49:36 -07001488 *
Christoph Lameter894b8782007-05-10 03:15:16 -07001489 * Processing is still very fast if new objects have been freed to the
1490 * regular freelist. In that case we simply take over the regular freelist
1491 * as the lockless freelist and zap the regular freelist.
Christoph Lameter81819f02007-05-06 14:49:36 -07001492 *
Christoph Lameter894b8782007-05-10 03:15:16 -07001493 * If that is not working then we fall back to the partial lists. We take the
1494 * first element of the freelist as the object to allocate now and move the
1495 * rest of the freelist to the lockless freelist.
1496 *
1497 * And if we were unable to get a new slab from the partial slab lists then
Christoph Lameter6446faa2008-02-15 23:45:26 -08001498 * we need to allocate a new slab. This is the slowest path since it involves
1499 * a call to the page allocator and the setup of a new slab.
Christoph Lameter81819f02007-05-06 14:49:36 -07001500 */
Christoph Lameter894b8782007-05-10 03:15:16 -07001501static void *__slab_alloc(struct kmem_cache *s,
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001502 gfp_t gfpflags, int node, void *addr, struct kmem_cache_cpu *c)
Christoph Lameter81819f02007-05-06 14:49:36 -07001503{
Christoph Lameter81819f02007-05-06 14:49:36 -07001504 void **object;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001505 struct page *new;
Christoph Lameter81819f02007-05-06 14:49:36 -07001506
Linus Torvaldse72e9c22008-03-27 20:56:33 -07001507 /* We handle __GFP_ZERO in the caller */
1508 gfpflags &= ~__GFP_ZERO;
1509
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001510 if (!c->page)
Christoph Lameter81819f02007-05-06 14:49:36 -07001511 goto new_slab;
1512
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001513 slab_lock(c->page);
1514 if (unlikely(!node_match(c, node)))
Christoph Lameter81819f02007-05-06 14:49:36 -07001515 goto another_slab;
Christoph Lameter6446faa2008-02-15 23:45:26 -08001516
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001517 stat(c, ALLOC_REFILL);
Christoph Lameter6446faa2008-02-15 23:45:26 -08001518
Christoph Lameter894b8782007-05-10 03:15:16 -07001519load_freelist:
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001520 object = c->page->freelist;
Christoph Lametera973e9d2008-03-01 13:40:44 -08001521 if (unlikely(!object))
Christoph Lameter81819f02007-05-06 14:49:36 -07001522 goto another_slab;
Andy Whitcroft8a380822008-07-23 21:27:18 -07001523 if (unlikely(SLABDEBUG && PageSlubDebug(c->page)))
Christoph Lameter81819f02007-05-06 14:49:36 -07001524 goto debug;
1525
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001526 c->freelist = object[c->offset];
Christoph Lameter39b26462008-04-14 19:11:30 +03001527 c->page->inuse = c->page->objects;
Christoph Lametera973e9d2008-03-01 13:40:44 -08001528 c->page->freelist = NULL;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001529 c->node = page_to_nid(c->page);
Christoph Lameter1f842602008-01-07 23:20:30 -08001530unlock_out:
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001531 slab_unlock(c->page);
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001532 stat(c, ALLOC_SLOWPATH);
Christoph Lameter81819f02007-05-06 14:49:36 -07001533 return object;
1534
1535another_slab:
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001536 deactivate_slab(s, c);
Christoph Lameter81819f02007-05-06 14:49:36 -07001537
1538new_slab:
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001539 new = get_partial(s, gfpflags, node);
1540 if (new) {
1541 c->page = new;
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001542 stat(c, ALLOC_FROM_PARTIAL);
Christoph Lameter894b8782007-05-10 03:15:16 -07001543 goto load_freelist;
Christoph Lameter81819f02007-05-06 14:49:36 -07001544 }
1545
Christoph Lameterb811c202007-10-16 23:25:51 -07001546 if (gfpflags & __GFP_WAIT)
1547 local_irq_enable();
1548
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001549 new = new_slab(s, gfpflags, node);
Christoph Lameterb811c202007-10-16 23:25:51 -07001550
1551 if (gfpflags & __GFP_WAIT)
1552 local_irq_disable();
1553
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001554 if (new) {
1555 c = get_cpu_slab(s, smp_processor_id());
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001556 stat(c, ALLOC_SLAB);
Christoph Lameter05aa3452007-11-05 11:31:58 -08001557 if (c->page)
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001558 flush_slab(s, c);
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001559 slab_lock(new);
Andy Whitcroft8a380822008-07-23 21:27:18 -07001560 __SetPageSlubFrozen(new);
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001561 c->page = new;
Christoph Lameter4b6f0752007-05-16 22:10:53 -07001562 goto load_freelist;
Christoph Lameter81819f02007-05-06 14:49:36 -07001563 }
Christoph Lameter71c7a062008-02-14 14:28:01 -08001564 return NULL;
Christoph Lameter81819f02007-05-06 14:49:36 -07001565debug:
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001566 if (!alloc_debug_processing(s, c->page, object, addr))
Christoph Lameter81819f02007-05-06 14:49:36 -07001567 goto another_slab;
Christoph Lameter894b8782007-05-10 03:15:16 -07001568
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001569 c->page->inuse++;
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001570 c->page->freelist = object[c->offset];
Christoph Lameteree3c72a2007-10-16 01:26:07 -07001571 c->node = -1;
Christoph Lameter1f842602008-01-07 23:20:30 -08001572 goto unlock_out;
Christoph Lameter894b8782007-05-10 03:15:16 -07001573}
1574
1575/*
1576 * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
1577 * have the fastpath folded into their functions. So no function call
1578 * overhead for requests that can be satisfied on the fastpath.
1579 *
1580 * The fastpath works by first checking if the lockless freelist can be used.
1581 * If not then __slab_alloc is called for slow processing.
1582 *
1583 * Otherwise we can simply pick the next object from the lockless free list.
1584 */
Pekka Enberg06428782008-01-07 23:20:27 -08001585static __always_inline void *slab_alloc(struct kmem_cache *s,
Christoph Lameterce15fea2007-07-17 04:03:28 -07001586 gfp_t gfpflags, int node, void *addr)
Christoph Lameter894b8782007-05-10 03:15:16 -07001587{
Christoph Lameter894b8782007-05-10 03:15:16 -07001588 void **object;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001589 struct kmem_cache_cpu *c;
Christoph Lameter1f842602008-01-07 23:20:30 -08001590 unsigned long flags;
Dmitry Adamushkobdb21922008-07-10 22:21:58 +02001591 unsigned int objsize;
Christoph Lameter1f842602008-01-07 23:20:30 -08001592
Christoph Lameter894b8782007-05-10 03:15:16 -07001593 local_irq_save(flags);
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001594 c = get_cpu_slab(s, smp_processor_id());
Dmitry Adamushkobdb21922008-07-10 22:21:58 +02001595 objsize = c->objsize;
Christoph Lametera973e9d2008-03-01 13:40:44 -08001596 if (unlikely(!c->freelist || !node_match(c, node)))
Christoph Lameter894b8782007-05-10 03:15:16 -07001597
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001598 object = __slab_alloc(s, gfpflags, node, addr, c);
Christoph Lameter894b8782007-05-10 03:15:16 -07001599
1600 else {
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001601 object = c->freelist;
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001602 c->freelist = object[c->offset];
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001603 stat(c, ALLOC_FASTPATH);
Christoph Lameter894b8782007-05-10 03:15:16 -07001604 }
1605 local_irq_restore(flags);
Christoph Lameterd07dbea2007-07-17 04:03:23 -07001606
1607 if (unlikely((gfpflags & __GFP_ZERO) && object))
Dmitry Adamushkobdb21922008-07-10 22:21:58 +02001608 memset(object, 0, objsize);
Christoph Lameterd07dbea2007-07-17 04:03:23 -07001609
Christoph Lameter894b8782007-05-10 03:15:16 -07001610 return object;
Christoph Lameter81819f02007-05-06 14:49:36 -07001611}
1612
1613void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags)
1614{
Christoph Lameterce15fea2007-07-17 04:03:28 -07001615 return slab_alloc(s, gfpflags, -1, __builtin_return_address(0));
Christoph Lameter81819f02007-05-06 14:49:36 -07001616}
1617EXPORT_SYMBOL(kmem_cache_alloc);
1618
1619#ifdef CONFIG_NUMA
1620void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, int node)
1621{
Christoph Lameterce15fea2007-07-17 04:03:28 -07001622 return slab_alloc(s, gfpflags, node, __builtin_return_address(0));
Christoph Lameter81819f02007-05-06 14:49:36 -07001623}
1624EXPORT_SYMBOL(kmem_cache_alloc_node);
1625#endif
1626
1627/*
Christoph Lameter894b8782007-05-10 03:15:16 -07001628 * Slow patch handling. This may still be called frequently since objects
1629 * have a longer lifetime than the cpu slabs in most processing loads.
Christoph Lameter81819f02007-05-06 14:49:36 -07001630 *
Christoph Lameter894b8782007-05-10 03:15:16 -07001631 * So we still attempt to reduce cache line usage. Just take the slab
1632 * lock and free the item. If there is no additional partial page
1633 * handling required then we can return immediately.
Christoph Lameter81819f02007-05-06 14:49:36 -07001634 */
Christoph Lameter894b8782007-05-10 03:15:16 -07001635static void __slab_free(struct kmem_cache *s, struct page *page,
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001636 void *x, void *addr, unsigned int offset)
Christoph Lameter81819f02007-05-06 14:49:36 -07001637{
1638 void *prior;
1639 void **object = (void *)x;
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001640 struct kmem_cache_cpu *c;
Christoph Lameter81819f02007-05-06 14:49:36 -07001641
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001642 c = get_cpu_slab(s, raw_smp_processor_id());
1643 stat(c, FREE_SLOWPATH);
Christoph Lameter81819f02007-05-06 14:49:36 -07001644 slab_lock(page);
1645
Andy Whitcroft8a380822008-07-23 21:27:18 -07001646 if (unlikely(SLABDEBUG && PageSlubDebug(page)))
Christoph Lameter81819f02007-05-06 14:49:36 -07001647 goto debug;
Christoph Lameter6446faa2008-02-15 23:45:26 -08001648
Christoph Lameter81819f02007-05-06 14:49:36 -07001649checks_ok:
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001650 prior = object[offset] = page->freelist;
Christoph Lameter81819f02007-05-06 14:49:36 -07001651 page->freelist = object;
1652 page->inuse--;
1653
Andy Whitcroft8a380822008-07-23 21:27:18 -07001654 if (unlikely(PageSlubFrozen(page))) {
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001655 stat(c, FREE_FROZEN);
Christoph Lameter81819f02007-05-06 14:49:36 -07001656 goto out_unlock;
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001657 }
Christoph Lameter81819f02007-05-06 14:49:36 -07001658
1659 if (unlikely(!page->inuse))
1660 goto slab_empty;
1661
1662 /*
Christoph Lameter6446faa2008-02-15 23:45:26 -08001663 * Objects left in the slab. If it was not on the partial list before
Christoph Lameter81819f02007-05-06 14:49:36 -07001664 * then add it.
1665 */
Christoph Lametera973e9d2008-03-01 13:40:44 -08001666 if (unlikely(!prior)) {
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001667 add_partial(get_node(s, page_to_nid(page)), page, 1);
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001668 stat(c, FREE_ADD_PARTIAL);
1669 }
Christoph Lameter81819f02007-05-06 14:49:36 -07001670
1671out_unlock:
1672 slab_unlock(page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001673 return;
1674
1675slab_empty:
Christoph Lametera973e9d2008-03-01 13:40:44 -08001676 if (prior) {
Christoph Lameter81819f02007-05-06 14:49:36 -07001677 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07001678 * Slab still on the partial list.
Christoph Lameter81819f02007-05-06 14:49:36 -07001679 */
1680 remove_partial(s, page);
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001681 stat(c, FREE_REMOVE_PARTIAL);
1682 }
Christoph Lameter81819f02007-05-06 14:49:36 -07001683 slab_unlock(page);
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001684 stat(c, FREE_SLAB);
Christoph Lameter81819f02007-05-06 14:49:36 -07001685 discard_slab(s, page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001686 return;
1687
1688debug:
Christoph Lameter3ec09742007-05-16 22:11:00 -07001689 if (!free_debug_processing(s, page, x, addr))
Christoph Lameter77c5e2d2007-05-06 14:49:42 -07001690 goto out_unlock;
Christoph Lameter77c5e2d2007-05-06 14:49:42 -07001691 goto checks_ok;
Christoph Lameter81819f02007-05-06 14:49:36 -07001692}
1693
Christoph Lameter894b8782007-05-10 03:15:16 -07001694/*
1695 * Fastpath with forced inlining to produce a kfree and kmem_cache_free that
1696 * can perform fastpath freeing without additional function calls.
1697 *
1698 * The fastpath is only possible if we are freeing to the current cpu slab
1699 * of this processor. This typically the case if we have just allocated
1700 * the item before.
1701 *
1702 * If fastpath is not possible then fall back to __slab_free where we deal
1703 * with all sorts of special processing.
1704 */
Pekka Enberg06428782008-01-07 23:20:27 -08001705static __always_inline void slab_free(struct kmem_cache *s,
Christoph Lameter894b8782007-05-10 03:15:16 -07001706 struct page *page, void *x, void *addr)
1707{
1708 void **object = (void *)x;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001709 struct kmem_cache_cpu *c;
Christoph Lameter1f842602008-01-07 23:20:30 -08001710 unsigned long flags;
1711
Christoph Lameter894b8782007-05-10 03:15:16 -07001712 local_irq_save(flags);
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001713 c = get_cpu_slab(s, smp_processor_id());
Christoph Lameter27d9e4e2008-02-15 23:45:25 -08001714 debug_check_no_locks_freed(object, c->objsize);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -07001715 if (!(s->flags & SLAB_DEBUG_OBJECTS))
1716 debug_check_no_obj_freed(object, s->objsize);
Christoph Lameteree3c72a2007-10-16 01:26:07 -07001717 if (likely(page == c->page && c->node >= 0)) {
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001718 object[c->offset] = c->freelist;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001719 c->freelist = object;
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001720 stat(c, FREE_FASTPATH);
Christoph Lameter894b8782007-05-10 03:15:16 -07001721 } else
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001722 __slab_free(s, page, x, addr, c->offset);
Christoph Lameter894b8782007-05-10 03:15:16 -07001723
1724 local_irq_restore(flags);
1725}
1726
Christoph Lameter81819f02007-05-06 14:49:36 -07001727void kmem_cache_free(struct kmem_cache *s, void *x)
1728{
Christoph Lameter77c5e2d2007-05-06 14:49:42 -07001729 struct page *page;
Christoph Lameter81819f02007-05-06 14:49:36 -07001730
Christoph Lameterb49af682007-05-06 14:49:41 -07001731 page = virt_to_head_page(x);
Christoph Lameter81819f02007-05-06 14:49:36 -07001732
Christoph Lameter77c5e2d2007-05-06 14:49:42 -07001733 slab_free(s, page, x, __builtin_return_address(0));
Christoph Lameter81819f02007-05-06 14:49:36 -07001734}
1735EXPORT_SYMBOL(kmem_cache_free);
1736
1737/* Figure out on which slab object the object resides */
1738static struct page *get_object_page(const void *x)
1739{
Christoph Lameterb49af682007-05-06 14:49:41 -07001740 struct page *page = virt_to_head_page(x);
Christoph Lameter81819f02007-05-06 14:49:36 -07001741
1742 if (!PageSlab(page))
1743 return NULL;
1744
1745 return page;
1746}
1747
1748/*
Christoph Lameter672bba32007-05-09 02:32:39 -07001749 * Object placement in a slab is made very easy because we always start at
1750 * offset 0. If we tune the size of the object to the alignment then we can
1751 * get the required alignment by putting one properly sized object after
1752 * another.
Christoph Lameter81819f02007-05-06 14:49:36 -07001753 *
1754 * Notice that the allocation order determines the sizes of the per cpu
1755 * caches. Each processor has always one slab available for allocations.
1756 * Increasing the allocation order reduces the number of times that slabs
Christoph Lameter672bba32007-05-09 02:32:39 -07001757 * must be moved on and off the partial lists and is therefore a factor in
Christoph Lameter81819f02007-05-06 14:49:36 -07001758 * locking overhead.
Christoph Lameter81819f02007-05-06 14:49:36 -07001759 */
1760
1761/*
1762 * Mininum / Maximum order of slab pages. This influences locking overhead
1763 * and slab fragmentation. A higher order reduces the number of partial slabs
1764 * and increases the number of allocations possible without having to
1765 * take the list_lock.
1766 */
1767static int slub_min_order;
Christoph Lameter114e9e82008-04-14 19:11:41 +03001768static int slub_max_order = PAGE_ALLOC_COSTLY_ORDER;
Christoph Lameter9b2cd502008-04-14 19:11:41 +03001769static int slub_min_objects;
Christoph Lameter81819f02007-05-06 14:49:36 -07001770
1771/*
1772 * Merge control. If this is set then no merging of slab caches will occur.
Christoph Lameter672bba32007-05-09 02:32:39 -07001773 * (Could be removed. This was introduced to pacify the merge skeptics.)
Christoph Lameter81819f02007-05-06 14:49:36 -07001774 */
1775static int slub_nomerge;
1776
1777/*
Christoph Lameter81819f02007-05-06 14:49:36 -07001778 * Calculate the order of allocation given an slab object size.
1779 *
Christoph Lameter672bba32007-05-09 02:32:39 -07001780 * The order of allocation has significant impact on performance and other
1781 * system components. Generally order 0 allocations should be preferred since
1782 * order 0 does not cause fragmentation in the page allocator. Larger objects
1783 * be problematic to put into order 0 slabs because there may be too much
Christoph Lameterc124f5b2008-04-14 19:13:29 +03001784 * unused space left. We go to a higher order if more than 1/16th of the slab
Christoph Lameter672bba32007-05-09 02:32:39 -07001785 * would be wasted.
Christoph Lameter81819f02007-05-06 14:49:36 -07001786 *
Christoph Lameter672bba32007-05-09 02:32:39 -07001787 * In order to reach satisfactory performance we must ensure that a minimum
1788 * number of objects is in one slab. Otherwise we may generate too much
1789 * activity on the partial lists which requires taking the list_lock. This is
1790 * less a concern for large slabs though which are rarely used.
Christoph Lameter81819f02007-05-06 14:49:36 -07001791 *
Christoph Lameter672bba32007-05-09 02:32:39 -07001792 * slub_max_order specifies the order where we begin to stop considering the
1793 * number of objects in a slab as critical. If we reach slub_max_order then
1794 * we try to keep the page order as low as possible. So we accept more waste
1795 * of space in favor of a small page order.
1796 *
1797 * Higher order allocations also allow the placement of more objects in a
1798 * slab and thereby reduce object handling overhead. If the user has
1799 * requested a higher mininum order then we start with that one instead of
1800 * the smallest order which will fit the object.
Christoph Lameter81819f02007-05-06 14:49:36 -07001801 */
Christoph Lameter5e6d4442007-05-09 02:32:46 -07001802static inline int slab_order(int size, int min_objects,
1803 int max_order, int fract_leftover)
Christoph Lameter81819f02007-05-06 14:49:36 -07001804{
1805 int order;
1806 int rem;
Christoph Lameter6300ea72007-07-17 04:03:20 -07001807 int min_order = slub_min_order;
Christoph Lameter81819f02007-05-06 14:49:36 -07001808
Christoph Lameter39b26462008-04-14 19:11:30 +03001809 if ((PAGE_SIZE << min_order) / size > 65535)
1810 return get_order(size * 65535) - 1;
1811
Christoph Lameter6300ea72007-07-17 04:03:20 -07001812 for (order = max(min_order,
Christoph Lameter5e6d4442007-05-09 02:32:46 -07001813 fls(min_objects * size - 1) - PAGE_SHIFT);
1814 order <= max_order; order++) {
1815
Christoph Lameter81819f02007-05-06 14:49:36 -07001816 unsigned long slab_size = PAGE_SIZE << order;
1817
Christoph Lameter5e6d4442007-05-09 02:32:46 -07001818 if (slab_size < min_objects * size)
Christoph Lameter81819f02007-05-06 14:49:36 -07001819 continue;
1820
Christoph Lameter81819f02007-05-06 14:49:36 -07001821 rem = slab_size % size;
1822
Christoph Lameter5e6d4442007-05-09 02:32:46 -07001823 if (rem <= slab_size / fract_leftover)
Christoph Lameter81819f02007-05-06 14:49:36 -07001824 break;
1825
1826 }
Christoph Lameter672bba32007-05-09 02:32:39 -07001827
Christoph Lameter81819f02007-05-06 14:49:36 -07001828 return order;
1829}
1830
Christoph Lameter5e6d4442007-05-09 02:32:46 -07001831static inline int calculate_order(int size)
1832{
1833 int order;
1834 int min_objects;
1835 int fraction;
1836
1837 /*
1838 * Attempt to find best configuration for a slab. This
1839 * works by first attempting to generate a layout with
1840 * the best configuration and backing off gradually.
1841 *
1842 * First we reduce the acceptable waste in a slab. Then
1843 * we reduce the minimum objects required in a slab.
1844 */
1845 min_objects = slub_min_objects;
Christoph Lameter9b2cd502008-04-14 19:11:41 +03001846 if (!min_objects)
1847 min_objects = 4 * (fls(nr_cpu_ids) + 1);
Christoph Lameter5e6d4442007-05-09 02:32:46 -07001848 while (min_objects > 1) {
Christoph Lameterc124f5b2008-04-14 19:13:29 +03001849 fraction = 16;
Christoph Lameter5e6d4442007-05-09 02:32:46 -07001850 while (fraction >= 4) {
1851 order = slab_order(size, min_objects,
1852 slub_max_order, fraction);
1853 if (order <= slub_max_order)
1854 return order;
1855 fraction /= 2;
1856 }
1857 min_objects /= 2;
1858 }
1859
1860 /*
1861 * We were unable to place multiple objects in a slab. Now
1862 * lets see if we can place a single object there.
1863 */
1864 order = slab_order(size, 1, slub_max_order, 1);
1865 if (order <= slub_max_order)
1866 return order;
1867
1868 /*
1869 * Doh this slab cannot be placed using slub_max_order.
1870 */
1871 order = slab_order(size, 1, MAX_ORDER, 1);
1872 if (order <= MAX_ORDER)
1873 return order;
1874 return -ENOSYS;
1875}
1876
Christoph Lameter81819f02007-05-06 14:49:36 -07001877/*
Christoph Lameter672bba32007-05-09 02:32:39 -07001878 * Figure out what the alignment of the objects will be.
Christoph Lameter81819f02007-05-06 14:49:36 -07001879 */
1880static unsigned long calculate_alignment(unsigned long flags,
1881 unsigned long align, unsigned long size)
1882{
1883 /*
Christoph Lameter6446faa2008-02-15 23:45:26 -08001884 * If the user wants hardware cache aligned objects then follow that
1885 * suggestion if the object is sufficiently large.
Christoph Lameter81819f02007-05-06 14:49:36 -07001886 *
Christoph Lameter6446faa2008-02-15 23:45:26 -08001887 * The hardware cache alignment cannot override the specified
1888 * alignment though. If that is greater then use it.
Christoph Lameter81819f02007-05-06 14:49:36 -07001889 */
Nick Pigginb6210382008-03-05 14:05:56 -08001890 if (flags & SLAB_HWCACHE_ALIGN) {
1891 unsigned long ralign = cache_line_size();
1892 while (size <= ralign / 2)
1893 ralign /= 2;
1894 align = max(align, ralign);
1895 }
Christoph Lameter81819f02007-05-06 14:49:36 -07001896
1897 if (align < ARCH_SLAB_MINALIGN)
Nick Pigginb6210382008-03-05 14:05:56 -08001898 align = ARCH_SLAB_MINALIGN;
Christoph Lameter81819f02007-05-06 14:49:36 -07001899
1900 return ALIGN(align, sizeof(void *));
1901}
1902
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001903static void init_kmem_cache_cpu(struct kmem_cache *s,
1904 struct kmem_cache_cpu *c)
1905{
1906 c->page = NULL;
Christoph Lametera973e9d2008-03-01 13:40:44 -08001907 c->freelist = NULL;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001908 c->node = 0;
Christoph Lameter42a9fdb2007-10-16 01:26:09 -07001909 c->offset = s->offset / sizeof(void *);
1910 c->objsize = s->objsize;
Pekka Enberg62f75532008-04-14 18:50:44 +03001911#ifdef CONFIG_SLUB_STATS
1912 memset(c->stat, 0, NR_SLUB_STAT_ITEMS * sizeof(unsigned));
1913#endif
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001914}
1915
Pekka Enberg5595cff2008-08-05 09:28:47 +03001916static void
1917init_kmem_cache_node(struct kmem_cache_node *n, struct kmem_cache *s)
Christoph Lameter81819f02007-05-06 14:49:36 -07001918{
1919 n->nr_partial = 0;
Pekka Enberg5595cff2008-08-05 09:28:47 +03001920
1921 /*
1922 * The larger the object size is, the more pages we want on the partial
1923 * list to avoid pounding the page allocator excessively.
1924 */
1925 n->min_partial = ilog2(s->size);
1926 if (n->min_partial < MIN_PARTIAL)
1927 n->min_partial = MIN_PARTIAL;
1928 else if (n->min_partial > MAX_PARTIAL)
1929 n->min_partial = MAX_PARTIAL;
1930
Christoph Lameter81819f02007-05-06 14:49:36 -07001931 spin_lock_init(&n->list_lock);
1932 INIT_LIST_HEAD(&n->partial);
Christoph Lameter8ab13722007-07-17 04:03:32 -07001933#ifdef CONFIG_SLUB_DEBUG
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001934 atomic_long_set(&n->nr_slabs, 0);
Salman Qazi02b71b72008-09-11 12:25:41 -07001935 atomic_long_set(&n->total_objects, 0);
Christoph Lameter643b1132007-05-06 14:49:42 -07001936 INIT_LIST_HEAD(&n->full);
Christoph Lameter8ab13722007-07-17 04:03:32 -07001937#endif
Christoph Lameter81819f02007-05-06 14:49:36 -07001938}
1939
Christoph Lameter4c93c3552007-10-16 01:26:08 -07001940#ifdef CONFIG_SMP
1941/*
1942 * Per cpu array for per cpu structures.
1943 *
1944 * The per cpu array places all kmem_cache_cpu structures from one processor
1945 * close together meaning that it becomes possible that multiple per cpu
1946 * structures are contained in one cacheline. This may be particularly
1947 * beneficial for the kmalloc caches.
1948 *
1949 * A desktop system typically has around 60-80 slabs. With 100 here we are
1950 * likely able to get per cpu structures for all caches from the array defined
1951 * here. We must be able to cover all kmalloc caches during bootstrap.
1952 *
1953 * If the per cpu array is exhausted then fall back to kmalloc
1954 * of individual cachelines. No sharing is possible then.
1955 */
1956#define NR_KMEM_CACHE_CPU 100
1957
1958static DEFINE_PER_CPU(struct kmem_cache_cpu,
1959 kmem_cache_cpu)[NR_KMEM_CACHE_CPU];
1960
1961static DEFINE_PER_CPU(struct kmem_cache_cpu *, kmem_cache_cpu_free);
1962static cpumask_t kmem_cach_cpu_free_init_once = CPU_MASK_NONE;
1963
1964static struct kmem_cache_cpu *alloc_kmem_cache_cpu(struct kmem_cache *s,
1965 int cpu, gfp_t flags)
1966{
1967 struct kmem_cache_cpu *c = per_cpu(kmem_cache_cpu_free, cpu);
1968
1969 if (c)
1970 per_cpu(kmem_cache_cpu_free, cpu) =
1971 (void *)c->freelist;
1972 else {
1973 /* Table overflow: So allocate ourselves */
1974 c = kmalloc_node(
1975 ALIGN(sizeof(struct kmem_cache_cpu), cache_line_size()),
1976 flags, cpu_to_node(cpu));
1977 if (!c)
1978 return NULL;
1979 }
1980
1981 init_kmem_cache_cpu(s, c);
1982 return c;
1983}
1984
1985static void free_kmem_cache_cpu(struct kmem_cache_cpu *c, int cpu)
1986{
1987 if (c < per_cpu(kmem_cache_cpu, cpu) ||
1988 c > per_cpu(kmem_cache_cpu, cpu) + NR_KMEM_CACHE_CPU) {
1989 kfree(c);
1990 return;
1991 }
1992 c->freelist = (void *)per_cpu(kmem_cache_cpu_free, cpu);
1993 per_cpu(kmem_cache_cpu_free, cpu) = c;
1994}
1995
1996static void free_kmem_cache_cpus(struct kmem_cache *s)
1997{
1998 int cpu;
1999
2000 for_each_online_cpu(cpu) {
2001 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
2002
2003 if (c) {
2004 s->cpu_slab[cpu] = NULL;
2005 free_kmem_cache_cpu(c, cpu);
2006 }
2007 }
2008}
2009
2010static int alloc_kmem_cache_cpus(struct kmem_cache *s, gfp_t flags)
2011{
2012 int cpu;
2013
2014 for_each_online_cpu(cpu) {
2015 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
2016
2017 if (c)
2018 continue;
2019
2020 c = alloc_kmem_cache_cpu(s, cpu, flags);
2021 if (!c) {
2022 free_kmem_cache_cpus(s);
2023 return 0;
2024 }
2025 s->cpu_slab[cpu] = c;
2026 }
2027 return 1;
2028}
2029
2030/*
2031 * Initialize the per cpu array.
2032 */
2033static void init_alloc_cpu_cpu(int cpu)
2034{
2035 int i;
2036
2037 if (cpu_isset(cpu, kmem_cach_cpu_free_init_once))
2038 return;
2039
2040 for (i = NR_KMEM_CACHE_CPU - 1; i >= 0; i--)
2041 free_kmem_cache_cpu(&per_cpu(kmem_cache_cpu, cpu)[i], cpu);
2042
2043 cpu_set(cpu, kmem_cach_cpu_free_init_once);
2044}
2045
2046static void __init init_alloc_cpu(void)
2047{
2048 int cpu;
2049
2050 for_each_online_cpu(cpu)
2051 init_alloc_cpu_cpu(cpu);
2052 }
2053
2054#else
2055static inline void free_kmem_cache_cpus(struct kmem_cache *s) {}
2056static inline void init_alloc_cpu(void) {}
2057
2058static inline int alloc_kmem_cache_cpus(struct kmem_cache *s, gfp_t flags)
2059{
2060 init_kmem_cache_cpu(s, &s->cpu_slab);
2061 return 1;
2062}
2063#endif
2064
Christoph Lameter81819f02007-05-06 14:49:36 -07002065#ifdef CONFIG_NUMA
2066/*
2067 * No kmalloc_node yet so do it by hand. We know that this is the first
2068 * slab on the node for this slabcache. There are no concurrent accesses
2069 * possible.
2070 *
2071 * Note that this function only works on the kmalloc_node_cache
Christoph Lameter4c93c3552007-10-16 01:26:08 -07002072 * when allocating for the kmalloc_node_cache. This is used for bootstrapping
2073 * memory on a fresh node that has no slab structures yet.
Christoph Lameter81819f02007-05-06 14:49:36 -07002074 */
Adrian Bunk1cd7daa2007-10-16 01:24:18 -07002075static struct kmem_cache_node *early_kmem_cache_node_alloc(gfp_t gfpflags,
2076 int node)
Christoph Lameter81819f02007-05-06 14:49:36 -07002077{
2078 struct page *page;
2079 struct kmem_cache_node *n;
rootba84c732008-01-07 23:20:28 -08002080 unsigned long flags;
Christoph Lameter81819f02007-05-06 14:49:36 -07002081
2082 BUG_ON(kmalloc_caches->size < sizeof(struct kmem_cache_node));
2083
Christoph Lametera2f92ee2007-08-22 14:01:57 -07002084 page = new_slab(kmalloc_caches, gfpflags, node);
Christoph Lameter81819f02007-05-06 14:49:36 -07002085
2086 BUG_ON(!page);
Christoph Lametera2f92ee2007-08-22 14:01:57 -07002087 if (page_to_nid(page) != node) {
2088 printk(KERN_ERR "SLUB: Unable to allocate memory from "
2089 "node %d\n", node);
2090 printk(KERN_ERR "SLUB: Allocating a useless per node structure "
2091 "in order to be able to continue\n");
2092 }
2093
Christoph Lameter81819f02007-05-06 14:49:36 -07002094 n = page->freelist;
2095 BUG_ON(!n);
2096 page->freelist = get_freepointer(kmalloc_caches, n);
2097 page->inuse++;
2098 kmalloc_caches->node[node] = n;
Christoph Lameter8ab13722007-07-17 04:03:32 -07002099#ifdef CONFIG_SLUB_DEBUG
Christoph Lameterd45f39c2007-07-17 04:03:21 -07002100 init_object(kmalloc_caches, n, 1);
2101 init_tracking(kmalloc_caches, n);
Christoph Lameter8ab13722007-07-17 04:03:32 -07002102#endif
Pekka Enberg5595cff2008-08-05 09:28:47 +03002103 init_kmem_cache_node(n, kmalloc_caches);
Christoph Lameter205ab992008-04-14 19:11:40 +03002104 inc_slabs_node(kmalloc_caches, node, page->objects);
Christoph Lameter6446faa2008-02-15 23:45:26 -08002105
rootba84c732008-01-07 23:20:28 -08002106 /*
2107 * lockdep requires consistent irq usage for each lock
2108 * so even though there cannot be a race this early in
2109 * the boot sequence, we still disable irqs.
2110 */
2111 local_irq_save(flags);
Christoph Lameter7c2e1322008-01-07 23:20:27 -08002112 add_partial(n, page, 0);
rootba84c732008-01-07 23:20:28 -08002113 local_irq_restore(flags);
Christoph Lameter81819f02007-05-06 14:49:36 -07002114 return n;
2115}
2116
2117static void free_kmem_cache_nodes(struct kmem_cache *s)
2118{
2119 int node;
2120
Christoph Lameterf64dc582007-10-16 01:25:33 -07002121 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002122 struct kmem_cache_node *n = s->node[node];
2123 if (n && n != &s->local_node)
2124 kmem_cache_free(kmalloc_caches, n);
2125 s->node[node] = NULL;
2126 }
2127}
2128
2129static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags)
2130{
2131 int node;
2132 int local_node;
2133
2134 if (slab_state >= UP)
2135 local_node = page_to_nid(virt_to_page(s));
2136 else
2137 local_node = 0;
2138
Christoph Lameterf64dc582007-10-16 01:25:33 -07002139 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002140 struct kmem_cache_node *n;
2141
2142 if (local_node == node)
2143 n = &s->local_node;
2144 else {
2145 if (slab_state == DOWN) {
2146 n = early_kmem_cache_node_alloc(gfpflags,
2147 node);
2148 continue;
2149 }
2150 n = kmem_cache_alloc_node(kmalloc_caches,
2151 gfpflags, node);
2152
2153 if (!n) {
2154 free_kmem_cache_nodes(s);
2155 return 0;
2156 }
2157
2158 }
2159 s->node[node] = n;
Pekka Enberg5595cff2008-08-05 09:28:47 +03002160 init_kmem_cache_node(n, s);
Christoph Lameter81819f02007-05-06 14:49:36 -07002161 }
2162 return 1;
2163}
2164#else
2165static void free_kmem_cache_nodes(struct kmem_cache *s)
2166{
2167}
2168
2169static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags)
2170{
Pekka Enberg5595cff2008-08-05 09:28:47 +03002171 init_kmem_cache_node(&s->local_node, s);
Christoph Lameter81819f02007-05-06 14:49:36 -07002172 return 1;
2173}
2174#endif
2175
2176/*
2177 * calculate_sizes() determines the order and the distribution of data within
2178 * a slab object.
2179 */
Christoph Lameter06b285d2008-04-14 19:11:41 +03002180static int calculate_sizes(struct kmem_cache *s, int forced_order)
Christoph Lameter81819f02007-05-06 14:49:36 -07002181{
2182 unsigned long flags = s->flags;
2183 unsigned long size = s->objsize;
2184 unsigned long align = s->align;
Christoph Lameter834f3d12008-04-14 19:11:31 +03002185 int order;
Christoph Lameter81819f02007-05-06 14:49:36 -07002186
2187 /*
Christoph Lameterd8b42bf2008-02-15 23:45:25 -08002188 * Round up object size to the next word boundary. We can only
2189 * place the free pointer at word boundaries and this determines
2190 * the possible location of the free pointer.
2191 */
2192 size = ALIGN(size, sizeof(void *));
2193
2194#ifdef CONFIG_SLUB_DEBUG
2195 /*
Christoph Lameter81819f02007-05-06 14:49:36 -07002196 * Determine if we can poison the object itself. If the user of
2197 * the slab may touch the object after free or before allocation
2198 * then we should never poison the object itself.
2199 */
2200 if ((flags & SLAB_POISON) && !(flags & SLAB_DESTROY_BY_RCU) &&
Christoph Lameterc59def9f2007-05-16 22:10:50 -07002201 !s->ctor)
Christoph Lameter81819f02007-05-06 14:49:36 -07002202 s->flags |= __OBJECT_POISON;
2203 else
2204 s->flags &= ~__OBJECT_POISON;
2205
Christoph Lameter81819f02007-05-06 14:49:36 -07002206
2207 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07002208 * If we are Redzoning then check if there is some space between the
Christoph Lameter81819f02007-05-06 14:49:36 -07002209 * end of the object and the free pointer. If not then add an
Christoph Lameter672bba32007-05-09 02:32:39 -07002210 * additional word to have some bytes to store Redzone information.
Christoph Lameter81819f02007-05-06 14:49:36 -07002211 */
2212 if ((flags & SLAB_RED_ZONE) && size == s->objsize)
2213 size += sizeof(void *);
Christoph Lameter41ecc552007-05-09 02:32:44 -07002214#endif
Christoph Lameter81819f02007-05-06 14:49:36 -07002215
2216 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07002217 * With that we have determined the number of bytes in actual use
2218 * by the object. This is the potential offset to the free pointer.
Christoph Lameter81819f02007-05-06 14:49:36 -07002219 */
2220 s->inuse = size;
2221
2222 if (((flags & (SLAB_DESTROY_BY_RCU | SLAB_POISON)) ||
Christoph Lameterc59def9f2007-05-16 22:10:50 -07002223 s->ctor)) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002224 /*
2225 * Relocate free pointer after the object if it is not
2226 * permitted to overwrite the first word of the object on
2227 * kmem_cache_free.
2228 *
2229 * This is the case if we do RCU, have a constructor or
2230 * destructor or are poisoning the objects.
2231 */
2232 s->offset = size;
2233 size += sizeof(void *);
2234 }
2235
Christoph Lameterc12b3c62007-05-23 13:57:31 -07002236#ifdef CONFIG_SLUB_DEBUG
Christoph Lameter81819f02007-05-06 14:49:36 -07002237 if (flags & SLAB_STORE_USER)
2238 /*
2239 * Need to store information about allocs and frees after
2240 * the object.
2241 */
2242 size += 2 * sizeof(struct track);
2243
Christoph Lameterbe7b3fb2007-05-09 02:32:36 -07002244 if (flags & SLAB_RED_ZONE)
Christoph Lameter81819f02007-05-06 14:49:36 -07002245 /*
2246 * Add some empty padding so that we can catch
2247 * overwrites from earlier objects rather than let
2248 * tracking information or the free pointer be
2249 * corrupted if an user writes before the start
2250 * of the object.
2251 */
2252 size += sizeof(void *);
Christoph Lameter41ecc552007-05-09 02:32:44 -07002253#endif
Christoph Lameter672bba32007-05-09 02:32:39 -07002254
Christoph Lameter81819f02007-05-06 14:49:36 -07002255 /*
2256 * Determine the alignment based on various parameters that the
Christoph Lameter65c02d42007-05-09 02:32:35 -07002257 * user specified and the dynamic determination of cache line size
2258 * on bootup.
Christoph Lameter81819f02007-05-06 14:49:36 -07002259 */
2260 align = calculate_alignment(flags, align, s->objsize);
2261
2262 /*
2263 * SLUB stores one object immediately after another beginning from
2264 * offset 0. In order to align the objects we have to simply size
2265 * each object to conform to the alignment.
2266 */
2267 size = ALIGN(size, align);
2268 s->size = size;
Christoph Lameter06b285d2008-04-14 19:11:41 +03002269 if (forced_order >= 0)
2270 order = forced_order;
2271 else
2272 order = calculate_order(size);
Christoph Lameter81819f02007-05-06 14:49:36 -07002273
Christoph Lameter834f3d12008-04-14 19:11:31 +03002274 if (order < 0)
Christoph Lameter81819f02007-05-06 14:49:36 -07002275 return 0;
2276
Christoph Lameterb7a49f02008-02-14 14:21:32 -08002277 s->allocflags = 0;
Christoph Lameter834f3d12008-04-14 19:11:31 +03002278 if (order)
Christoph Lameterb7a49f02008-02-14 14:21:32 -08002279 s->allocflags |= __GFP_COMP;
2280
2281 if (s->flags & SLAB_CACHE_DMA)
2282 s->allocflags |= SLUB_DMA;
2283
2284 if (s->flags & SLAB_RECLAIM_ACCOUNT)
2285 s->allocflags |= __GFP_RECLAIMABLE;
2286
Christoph Lameter81819f02007-05-06 14:49:36 -07002287 /*
2288 * Determine the number of objects per slab
2289 */
Christoph Lameter834f3d12008-04-14 19:11:31 +03002290 s->oo = oo_make(order, size);
Christoph Lameter65c33762008-04-14 19:11:40 +03002291 s->min = oo_make(get_order(size), size);
Christoph Lameter205ab992008-04-14 19:11:40 +03002292 if (oo_objects(s->oo) > oo_objects(s->max))
2293 s->max = s->oo;
Christoph Lameter81819f02007-05-06 14:49:36 -07002294
Christoph Lameter834f3d12008-04-14 19:11:31 +03002295 return !!oo_objects(s->oo);
Christoph Lameter81819f02007-05-06 14:49:36 -07002296
2297}
2298
Christoph Lameter81819f02007-05-06 14:49:36 -07002299static int kmem_cache_open(struct kmem_cache *s, gfp_t gfpflags,
2300 const char *name, size_t size,
2301 size_t align, unsigned long flags,
Alexey Dobriyan51cc5062008-07-25 19:45:34 -07002302 void (*ctor)(void *))
Christoph Lameter81819f02007-05-06 14:49:36 -07002303{
2304 memset(s, 0, kmem_size);
2305 s->name = name;
2306 s->ctor = ctor;
Christoph Lameter81819f02007-05-06 14:49:36 -07002307 s->objsize = size;
Christoph Lameter81819f02007-05-06 14:49:36 -07002308 s->align = align;
Christoph Lameterba0268a2007-09-11 15:24:11 -07002309 s->flags = kmem_cache_flags(size, flags, name, ctor);
Christoph Lameter81819f02007-05-06 14:49:36 -07002310
Christoph Lameter06b285d2008-04-14 19:11:41 +03002311 if (!calculate_sizes(s, -1))
Christoph Lameter81819f02007-05-06 14:49:36 -07002312 goto error;
2313
2314 s->refcount = 1;
2315#ifdef CONFIG_NUMA
Christoph Lametere2cb96b2008-08-19 08:51:22 -05002316 s->remote_node_defrag_ratio = 1000;
Christoph Lameter81819f02007-05-06 14:49:36 -07002317#endif
Christoph Lameterdfb4f092007-10-16 01:26:05 -07002318 if (!init_kmem_cache_nodes(s, gfpflags & ~SLUB_DMA))
2319 goto error;
Christoph Lameter81819f02007-05-06 14:49:36 -07002320
Christoph Lameterdfb4f092007-10-16 01:26:05 -07002321 if (alloc_kmem_cache_cpus(s, gfpflags & ~SLUB_DMA))
Christoph Lameter81819f02007-05-06 14:49:36 -07002322 return 1;
Christoph Lameter4c93c3552007-10-16 01:26:08 -07002323 free_kmem_cache_nodes(s);
Christoph Lameter81819f02007-05-06 14:49:36 -07002324error:
2325 if (flags & SLAB_PANIC)
2326 panic("Cannot create slab %s size=%lu realsize=%u "
2327 "order=%u offset=%u flags=%lx\n",
Christoph Lameter834f3d12008-04-14 19:11:31 +03002328 s->name, (unsigned long)size, s->size, oo_order(s->oo),
Christoph Lameter81819f02007-05-06 14:49:36 -07002329 s->offset, flags);
2330 return 0;
2331}
Christoph Lameter81819f02007-05-06 14:49:36 -07002332
2333/*
2334 * Check if a given pointer is valid
2335 */
2336int kmem_ptr_validate(struct kmem_cache *s, const void *object)
2337{
Pekka Enberg06428782008-01-07 23:20:27 -08002338 struct page *page;
Christoph Lameter81819f02007-05-06 14:49:36 -07002339
2340 page = get_object_page(object);
2341
2342 if (!page || s != page->slab)
2343 /* No slab or wrong slab */
2344 return 0;
2345
Christoph Lameterabcd08a2007-05-09 02:32:37 -07002346 if (!check_valid_pointer(s, page, object))
Christoph Lameter81819f02007-05-06 14:49:36 -07002347 return 0;
2348
2349 /*
2350 * We could also check if the object is on the slabs freelist.
2351 * But this would be too expensive and it seems that the main
Christoph Lameter6446faa2008-02-15 23:45:26 -08002352 * purpose of kmem_ptr_valid() is to check if the object belongs
Christoph Lameter81819f02007-05-06 14:49:36 -07002353 * to a certain slab.
2354 */
2355 return 1;
2356}
2357EXPORT_SYMBOL(kmem_ptr_validate);
2358
2359/*
2360 * Determine the size of a slab object
2361 */
2362unsigned int kmem_cache_size(struct kmem_cache *s)
2363{
2364 return s->objsize;
2365}
2366EXPORT_SYMBOL(kmem_cache_size);
2367
2368const char *kmem_cache_name(struct kmem_cache *s)
2369{
2370 return s->name;
2371}
2372EXPORT_SYMBOL(kmem_cache_name);
2373
Christoph Lameter33b12c32008-04-25 12:22:43 -07002374static void list_slab_objects(struct kmem_cache *s, struct page *page,
2375 const char *text)
Christoph Lameter81819f02007-05-06 14:49:36 -07002376{
Christoph Lameter33b12c32008-04-25 12:22:43 -07002377#ifdef CONFIG_SLUB_DEBUG
2378 void *addr = page_address(page);
2379 void *p;
2380 DECLARE_BITMAP(map, page->objects);
2381
2382 bitmap_zero(map, page->objects);
2383 slab_err(s, page, "%s", text);
2384 slab_lock(page);
2385 for_each_free_object(p, s, page->freelist)
2386 set_bit(slab_index(p, s, addr), map);
2387
2388 for_each_object(p, s, addr, page->objects) {
2389
2390 if (!test_bit(slab_index(p, s, addr), map)) {
2391 printk(KERN_ERR "INFO: Object 0x%p @offset=%tu\n",
2392 p, p - addr);
2393 print_tracking(s, p);
2394 }
2395 }
2396 slab_unlock(page);
2397#endif
2398}
2399
Christoph Lameter81819f02007-05-06 14:49:36 -07002400/*
Christoph Lameter599870b2008-04-23 12:36:52 -07002401 * Attempt to free all partial slabs on a node.
Christoph Lameter81819f02007-05-06 14:49:36 -07002402 */
Christoph Lameter599870b2008-04-23 12:36:52 -07002403static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n)
Christoph Lameter81819f02007-05-06 14:49:36 -07002404{
Christoph Lameter81819f02007-05-06 14:49:36 -07002405 unsigned long flags;
2406 struct page *page, *h;
2407
2408 spin_lock_irqsave(&n->list_lock, flags);
Christoph Lameter33b12c32008-04-25 12:22:43 -07002409 list_for_each_entry_safe(page, h, &n->partial, lru) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002410 if (!page->inuse) {
2411 list_del(&page->lru);
2412 discard_slab(s, page);
Christoph Lameter599870b2008-04-23 12:36:52 -07002413 n->nr_partial--;
Christoph Lameter33b12c32008-04-25 12:22:43 -07002414 } else {
2415 list_slab_objects(s, page,
2416 "Objects remaining on kmem_cache_close()");
Christoph Lameter599870b2008-04-23 12:36:52 -07002417 }
Christoph Lameter33b12c32008-04-25 12:22:43 -07002418 }
Christoph Lameter81819f02007-05-06 14:49:36 -07002419 spin_unlock_irqrestore(&n->list_lock, flags);
Christoph Lameter81819f02007-05-06 14:49:36 -07002420}
2421
2422/*
Christoph Lameter672bba32007-05-09 02:32:39 -07002423 * Release all resources used by a slab cache.
Christoph Lameter81819f02007-05-06 14:49:36 -07002424 */
Christoph Lameter0c710012007-07-17 04:03:24 -07002425static inline int kmem_cache_close(struct kmem_cache *s)
Christoph Lameter81819f02007-05-06 14:49:36 -07002426{
2427 int node;
2428
2429 flush_all(s);
2430
2431 /* Attempt to free all objects */
Christoph Lameter4c93c3552007-10-16 01:26:08 -07002432 free_kmem_cache_cpus(s);
Christoph Lameterf64dc582007-10-16 01:25:33 -07002433 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002434 struct kmem_cache_node *n = get_node(s, node);
2435
Christoph Lameter599870b2008-04-23 12:36:52 -07002436 free_partial(s, n);
2437 if (n->nr_partial || slabs_node(s, node))
Christoph Lameter81819f02007-05-06 14:49:36 -07002438 return 1;
2439 }
2440 free_kmem_cache_nodes(s);
2441 return 0;
2442}
2443
2444/*
2445 * Close a cache and release the kmem_cache structure
2446 * (must be used for caches created using kmem_cache_create)
2447 */
2448void kmem_cache_destroy(struct kmem_cache *s)
2449{
2450 down_write(&slub_lock);
2451 s->refcount--;
2452 if (!s->refcount) {
2453 list_del(&s->list);
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07002454 up_write(&slub_lock);
Pekka Enbergd629d812008-04-23 22:31:08 +03002455 if (kmem_cache_close(s)) {
2456 printk(KERN_ERR "SLUB %s: %s called for cache that "
2457 "still has objects.\n", s->name, __func__);
2458 dump_stack();
2459 }
Christoph Lameter81819f02007-05-06 14:49:36 -07002460 sysfs_slab_remove(s);
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07002461 } else
2462 up_write(&slub_lock);
Christoph Lameter81819f02007-05-06 14:49:36 -07002463}
2464EXPORT_SYMBOL(kmem_cache_destroy);
2465
2466/********************************************************************
2467 * Kmalloc subsystem
2468 *******************************************************************/
2469
Christoph Lameter331dc552008-02-14 14:28:09 -08002470struct kmem_cache kmalloc_caches[PAGE_SHIFT + 1] __cacheline_aligned;
Christoph Lameter81819f02007-05-06 14:49:36 -07002471EXPORT_SYMBOL(kmalloc_caches);
2472
Christoph Lameter81819f02007-05-06 14:49:36 -07002473static int __init setup_slub_min_order(char *str)
2474{
Pekka Enberg06428782008-01-07 23:20:27 -08002475 get_option(&str, &slub_min_order);
Christoph Lameter81819f02007-05-06 14:49:36 -07002476
2477 return 1;
2478}
2479
2480__setup("slub_min_order=", setup_slub_min_order);
2481
2482static int __init setup_slub_max_order(char *str)
2483{
Pekka Enberg06428782008-01-07 23:20:27 -08002484 get_option(&str, &slub_max_order);
Christoph Lameter81819f02007-05-06 14:49:36 -07002485
2486 return 1;
2487}
2488
2489__setup("slub_max_order=", setup_slub_max_order);
2490
2491static int __init setup_slub_min_objects(char *str)
2492{
Pekka Enberg06428782008-01-07 23:20:27 -08002493 get_option(&str, &slub_min_objects);
Christoph Lameter81819f02007-05-06 14:49:36 -07002494
2495 return 1;
2496}
2497
2498__setup("slub_min_objects=", setup_slub_min_objects);
2499
2500static int __init setup_slub_nomerge(char *str)
2501{
2502 slub_nomerge = 1;
2503 return 1;
2504}
2505
2506__setup("slub_nomerge", setup_slub_nomerge);
2507
Christoph Lameter81819f02007-05-06 14:49:36 -07002508static struct kmem_cache *create_kmalloc_cache(struct kmem_cache *s,
2509 const char *name, int size, gfp_t gfp_flags)
2510{
2511 unsigned int flags = 0;
2512
2513 if (gfp_flags & SLUB_DMA)
2514 flags = SLAB_CACHE_DMA;
2515
2516 down_write(&slub_lock);
2517 if (!kmem_cache_open(s, gfp_flags, name, size, ARCH_KMALLOC_MINALIGN,
Christoph Lameter319d1e22008-04-14 19:11:41 +03002518 flags, NULL))
Christoph Lameter81819f02007-05-06 14:49:36 -07002519 goto panic;
2520
2521 list_add(&s->list, &slab_caches);
2522 up_write(&slub_lock);
2523 if (sysfs_slab_add(s))
2524 goto panic;
2525 return s;
2526
2527panic:
2528 panic("Creation of kmalloc slab %s size=%d failed.\n", name, size);
2529}
2530
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002531#ifdef CONFIG_ZONE_DMA
Christoph Lameter4097d602008-04-14 18:51:18 +03002532static struct kmem_cache *kmalloc_caches_dma[PAGE_SHIFT + 1];
Christoph Lameter1ceef402007-08-07 15:11:48 -07002533
2534static void sysfs_add_func(struct work_struct *w)
2535{
2536 struct kmem_cache *s;
2537
2538 down_write(&slub_lock);
2539 list_for_each_entry(s, &slab_caches, list) {
2540 if (s->flags & __SYSFS_ADD_DEFERRED) {
2541 s->flags &= ~__SYSFS_ADD_DEFERRED;
2542 sysfs_slab_add(s);
2543 }
2544 }
2545 up_write(&slub_lock);
2546}
2547
2548static DECLARE_WORK(sysfs_add_work, sysfs_add_func);
2549
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002550static noinline struct kmem_cache *dma_kmalloc_cache(int index, gfp_t flags)
2551{
2552 struct kmem_cache *s;
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002553 char *text;
2554 size_t realsize;
2555
2556 s = kmalloc_caches_dma[index];
2557 if (s)
2558 return s;
2559
2560 /* Dynamically create dma cache */
Christoph Lameter1ceef402007-08-07 15:11:48 -07002561 if (flags & __GFP_WAIT)
2562 down_write(&slub_lock);
2563 else {
2564 if (!down_write_trylock(&slub_lock))
2565 goto out;
2566 }
2567
2568 if (kmalloc_caches_dma[index])
2569 goto unlock_out;
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002570
Christoph Lameter7b55f622007-07-17 04:03:27 -07002571 realsize = kmalloc_caches[index].objsize;
Ingo Molnar3adbefe2008-02-05 17:57:39 -08002572 text = kasprintf(flags & ~SLUB_DMA, "kmalloc_dma-%d",
2573 (unsigned int)realsize);
Christoph Lameter1ceef402007-08-07 15:11:48 -07002574 s = kmalloc(kmem_size, flags & ~SLUB_DMA);
2575
2576 if (!s || !text || !kmem_cache_open(s, flags, text,
2577 realsize, ARCH_KMALLOC_MINALIGN,
2578 SLAB_CACHE_DMA|__SYSFS_ADD_DEFERRED, NULL)) {
2579 kfree(s);
2580 kfree(text);
2581 goto unlock_out;
Christoph Lameterdfce8642007-07-17 04:03:25 -07002582 }
Christoph Lameter1ceef402007-08-07 15:11:48 -07002583
2584 list_add(&s->list, &slab_caches);
2585 kmalloc_caches_dma[index] = s;
2586
2587 schedule_work(&sysfs_add_work);
2588
2589unlock_out:
Christoph Lameterdfce8642007-07-17 04:03:25 -07002590 up_write(&slub_lock);
Christoph Lameter1ceef402007-08-07 15:11:48 -07002591out:
Christoph Lameterdfce8642007-07-17 04:03:25 -07002592 return kmalloc_caches_dma[index];
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002593}
2594#endif
2595
Christoph Lameterf1b26332007-07-17 04:03:26 -07002596/*
2597 * Conversion table for small slabs sizes / 8 to the index in the
2598 * kmalloc array. This is necessary for slabs < 192 since we have non power
2599 * of two cache sizes there. The size of larger slabs can be determined using
2600 * fls.
2601 */
2602static s8 size_index[24] = {
2603 3, /* 8 */
2604 4, /* 16 */
2605 5, /* 24 */
2606 5, /* 32 */
2607 6, /* 40 */
2608 6, /* 48 */
2609 6, /* 56 */
2610 6, /* 64 */
2611 1, /* 72 */
2612 1, /* 80 */
2613 1, /* 88 */
2614 1, /* 96 */
2615 7, /* 104 */
2616 7, /* 112 */
2617 7, /* 120 */
2618 7, /* 128 */
2619 2, /* 136 */
2620 2, /* 144 */
2621 2, /* 152 */
2622 2, /* 160 */
2623 2, /* 168 */
2624 2, /* 176 */
2625 2, /* 184 */
2626 2 /* 192 */
2627};
2628
Christoph Lameter81819f02007-05-06 14:49:36 -07002629static struct kmem_cache *get_slab(size_t size, gfp_t flags)
2630{
Christoph Lameterf1b26332007-07-17 04:03:26 -07002631 int index;
Christoph Lameter81819f02007-05-06 14:49:36 -07002632
Christoph Lameterf1b26332007-07-17 04:03:26 -07002633 if (size <= 192) {
2634 if (!size)
2635 return ZERO_SIZE_PTR;
Christoph Lameter81819f02007-05-06 14:49:36 -07002636
Christoph Lameterf1b26332007-07-17 04:03:26 -07002637 index = size_index[(size - 1) / 8];
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002638 } else
Christoph Lameterf1b26332007-07-17 04:03:26 -07002639 index = fls(size - 1);
Christoph Lameter81819f02007-05-06 14:49:36 -07002640
2641#ifdef CONFIG_ZONE_DMA
Christoph Lameterf1b26332007-07-17 04:03:26 -07002642 if (unlikely((flags & SLUB_DMA)))
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002643 return dma_kmalloc_cache(index, flags);
Christoph Lameterf1b26332007-07-17 04:03:26 -07002644
Christoph Lameter81819f02007-05-06 14:49:36 -07002645#endif
2646 return &kmalloc_caches[index];
2647}
2648
2649void *__kmalloc(size_t size, gfp_t flags)
2650{
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002651 struct kmem_cache *s;
Christoph Lameter81819f02007-05-06 14:49:36 -07002652
Christoph Lameter331dc552008-02-14 14:28:09 -08002653 if (unlikely(size > PAGE_SIZE))
Pekka Enbergeada35e2008-02-11 22:47:46 +02002654 return kmalloc_large(size, flags);
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002655
2656 s = get_slab(size, flags);
2657
2658 if (unlikely(ZERO_OR_NULL_PTR(s)))
Christoph Lameter6cb8f912007-07-17 04:03:22 -07002659 return s;
2660
Christoph Lameterce15fea2007-07-17 04:03:28 -07002661 return slab_alloc(s, flags, -1, __builtin_return_address(0));
Christoph Lameter81819f02007-05-06 14:49:36 -07002662}
2663EXPORT_SYMBOL(__kmalloc);
2664
Christoph Lameterf619cfe2008-03-01 13:56:40 -08002665static void *kmalloc_large_node(size_t size, gfp_t flags, int node)
2666{
2667 struct page *page = alloc_pages_node(node, flags | __GFP_COMP,
2668 get_order(size));
2669
2670 if (page)
2671 return page_address(page);
2672 else
2673 return NULL;
2674}
2675
Christoph Lameter81819f02007-05-06 14:49:36 -07002676#ifdef CONFIG_NUMA
2677void *__kmalloc_node(size_t size, gfp_t flags, int node)
2678{
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002679 struct kmem_cache *s;
Christoph Lameter81819f02007-05-06 14:49:36 -07002680
Christoph Lameter331dc552008-02-14 14:28:09 -08002681 if (unlikely(size > PAGE_SIZE))
Christoph Lameterf619cfe2008-03-01 13:56:40 -08002682 return kmalloc_large_node(size, flags, node);
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002683
2684 s = get_slab(size, flags);
2685
2686 if (unlikely(ZERO_OR_NULL_PTR(s)))
Christoph Lameter6cb8f912007-07-17 04:03:22 -07002687 return s;
2688
Christoph Lameterce15fea2007-07-17 04:03:28 -07002689 return slab_alloc(s, flags, node, __builtin_return_address(0));
Christoph Lameter81819f02007-05-06 14:49:36 -07002690}
2691EXPORT_SYMBOL(__kmalloc_node);
2692#endif
2693
2694size_t ksize(const void *object)
2695{
Christoph Lameter272c1d22007-06-08 13:46:49 -07002696 struct page *page;
Christoph Lameter81819f02007-05-06 14:49:36 -07002697 struct kmem_cache *s;
2698
Christoph Lameteref8b4522007-10-16 01:24:46 -07002699 if (unlikely(object == ZERO_SIZE_PTR))
Christoph Lameter272c1d22007-06-08 13:46:49 -07002700 return 0;
2701
Vegard Nossum294a80a2007-12-04 23:45:30 -08002702 page = virt_to_head_page(object);
Vegard Nossum294a80a2007-12-04 23:45:30 -08002703
Pekka Enberg76994412008-05-22 19:22:25 +03002704 if (unlikely(!PageSlab(page))) {
2705 WARN_ON(!PageCompound(page));
Vegard Nossum294a80a2007-12-04 23:45:30 -08002706 return PAGE_SIZE << compound_order(page);
Pekka Enberg76994412008-05-22 19:22:25 +03002707 }
Christoph Lameter81819f02007-05-06 14:49:36 -07002708 s = page->slab;
Christoph Lameter81819f02007-05-06 14:49:36 -07002709
Christoph Lameterae20bfd2008-02-15 23:45:25 -08002710#ifdef CONFIG_SLUB_DEBUG
Christoph Lameter81819f02007-05-06 14:49:36 -07002711 /*
2712 * Debugging requires use of the padding between object
2713 * and whatever may come after it.
2714 */
2715 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
2716 return s->objsize;
2717
Christoph Lameterae20bfd2008-02-15 23:45:25 -08002718#endif
Christoph Lameter81819f02007-05-06 14:49:36 -07002719 /*
2720 * If we have the need to store the freelist pointer
2721 * back there or track user information then we can
2722 * only use the space before that information.
2723 */
2724 if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER))
2725 return s->inuse;
Christoph Lameter81819f02007-05-06 14:49:36 -07002726 /*
2727 * Else we can use all the padding etc for the allocation
2728 */
2729 return s->size;
2730}
Christoph Lameter81819f02007-05-06 14:49:36 -07002731
2732void kfree(const void *x)
2733{
Christoph Lameter81819f02007-05-06 14:49:36 -07002734 struct page *page;
Christoph Lameter5bb983b2008-02-07 17:47:41 -08002735 void *object = (void *)x;
Christoph Lameter81819f02007-05-06 14:49:36 -07002736
Satyam Sharma2408c552007-10-16 01:24:44 -07002737 if (unlikely(ZERO_OR_NULL_PTR(x)))
Christoph Lameter81819f02007-05-06 14:49:36 -07002738 return;
2739
Christoph Lameterb49af682007-05-06 14:49:41 -07002740 page = virt_to_head_page(x);
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002741 if (unlikely(!PageSlab(page))) {
Christoph Lameter09375022008-05-28 10:32:22 -07002742 BUG_ON(!PageCompound(page));
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002743 put_page(page);
2744 return;
2745 }
Christoph Lameter5bb983b2008-02-07 17:47:41 -08002746 slab_free(page->slab, page, object, __builtin_return_address(0));
Christoph Lameter81819f02007-05-06 14:49:36 -07002747}
2748EXPORT_SYMBOL(kfree);
2749
Christoph Lameter2086d262007-05-06 14:49:46 -07002750/*
Christoph Lameter672bba32007-05-09 02:32:39 -07002751 * kmem_cache_shrink removes empty slabs from the partial lists and sorts
2752 * the remaining slabs by the number of items in use. The slabs with the
2753 * most items in use come first. New allocations will then fill those up
2754 * and thus they can be removed from the partial lists.
2755 *
2756 * The slabs with the least items are placed last. This results in them
2757 * being allocated from last increasing the chance that the last objects
2758 * are freed in them.
Christoph Lameter2086d262007-05-06 14:49:46 -07002759 */
2760int kmem_cache_shrink(struct kmem_cache *s)
2761{
2762 int node;
2763 int i;
2764 struct kmem_cache_node *n;
2765 struct page *page;
2766 struct page *t;
Christoph Lameter205ab992008-04-14 19:11:40 +03002767 int objects = oo_objects(s->max);
Christoph Lameter2086d262007-05-06 14:49:46 -07002768 struct list_head *slabs_by_inuse =
Christoph Lameter834f3d12008-04-14 19:11:31 +03002769 kmalloc(sizeof(struct list_head) * objects, GFP_KERNEL);
Christoph Lameter2086d262007-05-06 14:49:46 -07002770 unsigned long flags;
2771
2772 if (!slabs_by_inuse)
2773 return -ENOMEM;
2774
2775 flush_all(s);
Christoph Lameterf64dc582007-10-16 01:25:33 -07002776 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter2086d262007-05-06 14:49:46 -07002777 n = get_node(s, node);
2778
2779 if (!n->nr_partial)
2780 continue;
2781
Christoph Lameter834f3d12008-04-14 19:11:31 +03002782 for (i = 0; i < objects; i++)
Christoph Lameter2086d262007-05-06 14:49:46 -07002783 INIT_LIST_HEAD(slabs_by_inuse + i);
2784
2785 spin_lock_irqsave(&n->list_lock, flags);
2786
2787 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07002788 * Build lists indexed by the items in use in each slab.
Christoph Lameter2086d262007-05-06 14:49:46 -07002789 *
Christoph Lameter672bba32007-05-09 02:32:39 -07002790 * Note that concurrent frees may occur while we hold the
2791 * list_lock. page->inuse here is the upper limit.
Christoph Lameter2086d262007-05-06 14:49:46 -07002792 */
2793 list_for_each_entry_safe(page, t, &n->partial, lru) {
2794 if (!page->inuse && slab_trylock(page)) {
2795 /*
2796 * Must hold slab lock here because slab_free
2797 * may have freed the last object and be
2798 * waiting to release the slab.
2799 */
2800 list_del(&page->lru);
2801 n->nr_partial--;
2802 slab_unlock(page);
2803 discard_slab(s, page);
2804 } else {
Christoph Lameterfcda3d82007-07-30 13:06:46 -07002805 list_move(&page->lru,
2806 slabs_by_inuse + page->inuse);
Christoph Lameter2086d262007-05-06 14:49:46 -07002807 }
2808 }
2809
Christoph Lameter2086d262007-05-06 14:49:46 -07002810 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07002811 * Rebuild the partial list with the slabs filled up most
2812 * first and the least used slabs at the end.
Christoph Lameter2086d262007-05-06 14:49:46 -07002813 */
Christoph Lameter834f3d12008-04-14 19:11:31 +03002814 for (i = objects - 1; i >= 0; i--)
Christoph Lameter2086d262007-05-06 14:49:46 -07002815 list_splice(slabs_by_inuse + i, n->partial.prev);
2816
Christoph Lameter2086d262007-05-06 14:49:46 -07002817 spin_unlock_irqrestore(&n->list_lock, flags);
2818 }
2819
2820 kfree(slabs_by_inuse);
2821 return 0;
2822}
2823EXPORT_SYMBOL(kmem_cache_shrink);
2824
Yasunori Gotob9049e22007-10-21 16:41:37 -07002825#if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)
2826static int slab_mem_going_offline_callback(void *arg)
2827{
2828 struct kmem_cache *s;
2829
2830 down_read(&slub_lock);
2831 list_for_each_entry(s, &slab_caches, list)
2832 kmem_cache_shrink(s);
2833 up_read(&slub_lock);
2834
2835 return 0;
2836}
2837
2838static void slab_mem_offline_callback(void *arg)
2839{
2840 struct kmem_cache_node *n;
2841 struct kmem_cache *s;
2842 struct memory_notify *marg = arg;
2843 int offline_node;
2844
2845 offline_node = marg->status_change_nid;
2846
2847 /*
2848 * If the node still has available memory. we need kmem_cache_node
2849 * for it yet.
2850 */
2851 if (offline_node < 0)
2852 return;
2853
2854 down_read(&slub_lock);
2855 list_for_each_entry(s, &slab_caches, list) {
2856 n = get_node(s, offline_node);
2857 if (n) {
2858 /*
2859 * if n->nr_slabs > 0, slabs still exist on the node
2860 * that is going down. We were unable to free them,
2861 * and offline_pages() function shoudn't call this
2862 * callback. So, we must fail.
2863 */
Christoph Lameter0f389ec2008-04-14 18:53:02 +03002864 BUG_ON(slabs_node(s, offline_node));
Yasunori Gotob9049e22007-10-21 16:41:37 -07002865
2866 s->node[offline_node] = NULL;
2867 kmem_cache_free(kmalloc_caches, n);
2868 }
2869 }
2870 up_read(&slub_lock);
2871}
2872
2873static int slab_mem_going_online_callback(void *arg)
2874{
2875 struct kmem_cache_node *n;
2876 struct kmem_cache *s;
2877 struct memory_notify *marg = arg;
2878 int nid = marg->status_change_nid;
2879 int ret = 0;
2880
2881 /*
2882 * If the node's memory is already available, then kmem_cache_node is
2883 * already created. Nothing to do.
2884 */
2885 if (nid < 0)
2886 return 0;
2887
2888 /*
Christoph Lameter0121c6192008-04-29 16:11:12 -07002889 * We are bringing a node online. No memory is available yet. We must
Yasunori Gotob9049e22007-10-21 16:41:37 -07002890 * allocate a kmem_cache_node structure in order to bring the node
2891 * online.
2892 */
2893 down_read(&slub_lock);
2894 list_for_each_entry(s, &slab_caches, list) {
2895 /*
2896 * XXX: kmem_cache_alloc_node will fallback to other nodes
2897 * since memory is not yet available from the node that
2898 * is brought up.
2899 */
2900 n = kmem_cache_alloc(kmalloc_caches, GFP_KERNEL);
2901 if (!n) {
2902 ret = -ENOMEM;
2903 goto out;
2904 }
Pekka Enberg5595cff2008-08-05 09:28:47 +03002905 init_kmem_cache_node(n, s);
Yasunori Gotob9049e22007-10-21 16:41:37 -07002906 s->node[nid] = n;
2907 }
2908out:
2909 up_read(&slub_lock);
2910 return ret;
2911}
2912
2913static int slab_memory_callback(struct notifier_block *self,
2914 unsigned long action, void *arg)
2915{
2916 int ret = 0;
2917
2918 switch (action) {
2919 case MEM_GOING_ONLINE:
2920 ret = slab_mem_going_online_callback(arg);
2921 break;
2922 case MEM_GOING_OFFLINE:
2923 ret = slab_mem_going_offline_callback(arg);
2924 break;
2925 case MEM_OFFLINE:
2926 case MEM_CANCEL_ONLINE:
2927 slab_mem_offline_callback(arg);
2928 break;
2929 case MEM_ONLINE:
2930 case MEM_CANCEL_OFFLINE:
2931 break;
2932 }
2933
2934 ret = notifier_from_errno(ret);
2935 return ret;
2936}
2937
2938#endif /* CONFIG_MEMORY_HOTPLUG */
2939
Christoph Lameter81819f02007-05-06 14:49:36 -07002940/********************************************************************
2941 * Basic setup of slabs
2942 *******************************************************************/
2943
2944void __init kmem_cache_init(void)
2945{
2946 int i;
Christoph Lameter4b356be2007-06-16 10:16:13 -07002947 int caches = 0;
Christoph Lameter81819f02007-05-06 14:49:36 -07002948
Christoph Lameter4c93c3552007-10-16 01:26:08 -07002949 init_alloc_cpu();
2950
Christoph Lameter81819f02007-05-06 14:49:36 -07002951#ifdef CONFIG_NUMA
2952 /*
2953 * Must first have the slab cache available for the allocations of the
Christoph Lameter672bba32007-05-09 02:32:39 -07002954 * struct kmem_cache_node's. There is special bootstrap code in
Christoph Lameter81819f02007-05-06 14:49:36 -07002955 * kmem_cache_open for slab_state == DOWN.
2956 */
2957 create_kmalloc_cache(&kmalloc_caches[0], "kmem_cache_node",
2958 sizeof(struct kmem_cache_node), GFP_KERNEL);
Christoph Lameter8ffa6872007-05-31 00:40:51 -07002959 kmalloc_caches[0].refcount = -1;
Christoph Lameter4b356be2007-06-16 10:16:13 -07002960 caches++;
Yasunori Gotob9049e22007-10-21 16:41:37 -07002961
Nadia Derbey0c40ba42008-04-29 01:00:41 -07002962 hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI);
Christoph Lameter81819f02007-05-06 14:49:36 -07002963#endif
2964
2965 /* Able to allocate the per node structures */
2966 slab_state = PARTIAL;
2967
2968 /* Caches that are not of the two-to-the-power-of size */
Christoph Lameter4b356be2007-06-16 10:16:13 -07002969 if (KMALLOC_MIN_SIZE <= 64) {
2970 create_kmalloc_cache(&kmalloc_caches[1],
Christoph Lameter81819f02007-05-06 14:49:36 -07002971 "kmalloc-96", 96, GFP_KERNEL);
Christoph Lameter4b356be2007-06-16 10:16:13 -07002972 caches++;
Christoph Lameter4b356be2007-06-16 10:16:13 -07002973 create_kmalloc_cache(&kmalloc_caches[2],
Christoph Lameter81819f02007-05-06 14:49:36 -07002974 "kmalloc-192", 192, GFP_KERNEL);
Christoph Lameter4b356be2007-06-16 10:16:13 -07002975 caches++;
2976 }
Christoph Lameter81819f02007-05-06 14:49:36 -07002977
Christoph Lameter331dc552008-02-14 14:28:09 -08002978 for (i = KMALLOC_SHIFT_LOW; i <= PAGE_SHIFT; i++) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002979 create_kmalloc_cache(&kmalloc_caches[i],
2980 "kmalloc", 1 << i, GFP_KERNEL);
Christoph Lameter4b356be2007-06-16 10:16:13 -07002981 caches++;
2982 }
Christoph Lameter81819f02007-05-06 14:49:36 -07002983
Christoph Lameterf1b26332007-07-17 04:03:26 -07002984
2985 /*
2986 * Patch up the size_index table if we have strange large alignment
2987 * requirements for the kmalloc array. This is only the case for
Christoph Lameter6446faa2008-02-15 23:45:26 -08002988 * MIPS it seems. The standard arches will not generate any code here.
Christoph Lameterf1b26332007-07-17 04:03:26 -07002989 *
2990 * Largest permitted alignment is 256 bytes due to the way we
2991 * handle the index determination for the smaller caches.
2992 *
2993 * Make sure that nothing crazy happens if someone starts tinkering
2994 * around with ARCH_KMALLOC_MINALIGN
2995 */
2996 BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
2997 (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
2998
Christoph Lameter12ad6842007-07-17 04:03:28 -07002999 for (i = 8; i < KMALLOC_MIN_SIZE; i += 8)
Christoph Lameterf1b26332007-07-17 04:03:26 -07003000 size_index[(i - 1) / 8] = KMALLOC_SHIFT_LOW;
3001
Christoph Lameter41d54d32008-07-03 09:14:26 -05003002 if (KMALLOC_MIN_SIZE == 128) {
3003 /*
3004 * The 192 byte sized cache is not used if the alignment
3005 * is 128 byte. Redirect kmalloc to use the 256 byte cache
3006 * instead.
3007 */
3008 for (i = 128 + 8; i <= 192; i += 8)
3009 size_index[(i - 1) / 8] = 8;
3010 }
3011
Christoph Lameter81819f02007-05-06 14:49:36 -07003012 slab_state = UP;
3013
3014 /* Provide the correct kmalloc names now that the caches are up */
Christoph Lameter331dc552008-02-14 14:28:09 -08003015 for (i = KMALLOC_SHIFT_LOW; i <= PAGE_SHIFT; i++)
Christoph Lameter81819f02007-05-06 14:49:36 -07003016 kmalloc_caches[i]. name =
3017 kasprintf(GFP_KERNEL, "kmalloc-%d", 1 << i);
3018
3019#ifdef CONFIG_SMP
3020 register_cpu_notifier(&slab_notifier);
Christoph Lameter4c93c3552007-10-16 01:26:08 -07003021 kmem_size = offsetof(struct kmem_cache, cpu_slab) +
3022 nr_cpu_ids * sizeof(struct kmem_cache_cpu *);
3023#else
3024 kmem_size = sizeof(struct kmem_cache);
Christoph Lameter81819f02007-05-06 14:49:36 -07003025#endif
3026
Ingo Molnar3adbefe2008-02-05 17:57:39 -08003027 printk(KERN_INFO
3028 "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d,"
Christoph Lameter4b356be2007-06-16 10:16:13 -07003029 " CPUs=%d, Nodes=%d\n",
3030 caches, cache_line_size(),
Christoph Lameter81819f02007-05-06 14:49:36 -07003031 slub_min_order, slub_max_order, slub_min_objects,
3032 nr_cpu_ids, nr_node_ids);
3033}
3034
3035/*
3036 * Find a mergeable slab cache
3037 */
3038static int slab_unmergeable(struct kmem_cache *s)
3039{
3040 if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE))
3041 return 1;
3042
Christoph Lameterc59def9f2007-05-16 22:10:50 -07003043 if (s->ctor)
Christoph Lameter81819f02007-05-06 14:49:36 -07003044 return 1;
3045
Christoph Lameter8ffa6872007-05-31 00:40:51 -07003046 /*
3047 * We may have set a slab to be unmergeable during bootstrap.
3048 */
3049 if (s->refcount < 0)
3050 return 1;
3051
Christoph Lameter81819f02007-05-06 14:49:36 -07003052 return 0;
3053}
3054
3055static struct kmem_cache *find_mergeable(size_t size,
Christoph Lameterba0268a2007-09-11 15:24:11 -07003056 size_t align, unsigned long flags, const char *name,
Alexey Dobriyan51cc5062008-07-25 19:45:34 -07003057 void (*ctor)(void *))
Christoph Lameter81819f02007-05-06 14:49:36 -07003058{
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07003059 struct kmem_cache *s;
Christoph Lameter81819f02007-05-06 14:49:36 -07003060
3061 if (slub_nomerge || (flags & SLUB_NEVER_MERGE))
3062 return NULL;
3063
Christoph Lameterc59def9f2007-05-16 22:10:50 -07003064 if (ctor)
Christoph Lameter81819f02007-05-06 14:49:36 -07003065 return NULL;
3066
3067 size = ALIGN(size, sizeof(void *));
3068 align = calculate_alignment(flags, align, size);
3069 size = ALIGN(size, align);
Christoph Lameterba0268a2007-09-11 15:24:11 -07003070 flags = kmem_cache_flags(size, flags, name, NULL);
Christoph Lameter81819f02007-05-06 14:49:36 -07003071
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07003072 list_for_each_entry(s, &slab_caches, list) {
Christoph Lameter81819f02007-05-06 14:49:36 -07003073 if (slab_unmergeable(s))
3074 continue;
3075
3076 if (size > s->size)
3077 continue;
3078
Christoph Lameterba0268a2007-09-11 15:24:11 -07003079 if ((flags & SLUB_MERGE_SAME) != (s->flags & SLUB_MERGE_SAME))
Christoph Lameter81819f02007-05-06 14:49:36 -07003080 continue;
3081 /*
3082 * Check if alignment is compatible.
3083 * Courtesy of Adrian Drzewiecki
3084 */
Pekka Enberg06428782008-01-07 23:20:27 -08003085 if ((s->size & ~(align - 1)) != s->size)
Christoph Lameter81819f02007-05-06 14:49:36 -07003086 continue;
3087
3088 if (s->size - size >= sizeof(void *))
3089 continue;
3090
3091 return s;
3092 }
3093 return NULL;
3094}
3095
3096struct kmem_cache *kmem_cache_create(const char *name, size_t size,
Alexey Dobriyan51cc5062008-07-25 19:45:34 -07003097 size_t align, unsigned long flags, void (*ctor)(void *))
Christoph Lameter81819f02007-05-06 14:49:36 -07003098{
3099 struct kmem_cache *s;
3100
3101 down_write(&slub_lock);
Christoph Lameterba0268a2007-09-11 15:24:11 -07003102 s = find_mergeable(size, align, flags, name, ctor);
Christoph Lameter81819f02007-05-06 14:49:36 -07003103 if (s) {
Christoph Lameter42a9fdb2007-10-16 01:26:09 -07003104 int cpu;
3105
Christoph Lameter81819f02007-05-06 14:49:36 -07003106 s->refcount++;
3107 /*
3108 * Adjust the object sizes so that we clear
3109 * the complete object on kzalloc.
3110 */
3111 s->objsize = max(s->objsize, (int)size);
Christoph Lameter42a9fdb2007-10-16 01:26:09 -07003112
3113 /*
3114 * And then we need to update the object size in the
3115 * per cpu structures
3116 */
3117 for_each_online_cpu(cpu)
3118 get_cpu_slab(s, cpu)->objsize = s->objsize;
Christoph Lameter6446faa2008-02-15 23:45:26 -08003119
Christoph Lameter81819f02007-05-06 14:49:36 -07003120 s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *)));
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07003121 up_write(&slub_lock);
Christoph Lameter6446faa2008-02-15 23:45:26 -08003122
Christoph Lameter81819f02007-05-06 14:49:36 -07003123 if (sysfs_slab_alias(s, name))
3124 goto err;
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07003125 return s;
3126 }
Christoph Lameter6446faa2008-02-15 23:45:26 -08003127
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07003128 s = kmalloc(kmem_size, GFP_KERNEL);
3129 if (s) {
3130 if (kmem_cache_open(s, GFP_KERNEL, name,
Christoph Lameterc59def9f2007-05-16 22:10:50 -07003131 size, align, flags, ctor)) {
Christoph Lameter81819f02007-05-06 14:49:36 -07003132 list_add(&s->list, &slab_caches);
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07003133 up_write(&slub_lock);
3134 if (sysfs_slab_add(s))
3135 goto err;
3136 return s;
3137 }
3138 kfree(s);
Christoph Lameter81819f02007-05-06 14:49:36 -07003139 }
3140 up_write(&slub_lock);
Christoph Lameter81819f02007-05-06 14:49:36 -07003141
3142err:
Christoph Lameter81819f02007-05-06 14:49:36 -07003143 if (flags & SLAB_PANIC)
3144 panic("Cannot create slabcache %s\n", name);
3145 else
3146 s = NULL;
3147 return s;
3148}
3149EXPORT_SYMBOL(kmem_cache_create);
3150
Christoph Lameter81819f02007-05-06 14:49:36 -07003151#ifdef CONFIG_SMP
Christoph Lameter27390bc2007-06-01 00:47:09 -07003152/*
Christoph Lameter672bba32007-05-09 02:32:39 -07003153 * Use the cpu notifier to insure that the cpu slabs are flushed when
3154 * necessary.
Christoph Lameter81819f02007-05-06 14:49:36 -07003155 */
3156static int __cpuinit slab_cpuup_callback(struct notifier_block *nfb,
3157 unsigned long action, void *hcpu)
3158{
3159 long cpu = (long)hcpu;
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07003160 struct kmem_cache *s;
3161 unsigned long flags;
Christoph Lameter81819f02007-05-06 14:49:36 -07003162
3163 switch (action) {
Christoph Lameter4c93c3552007-10-16 01:26:08 -07003164 case CPU_UP_PREPARE:
3165 case CPU_UP_PREPARE_FROZEN:
3166 init_alloc_cpu_cpu(cpu);
3167 down_read(&slub_lock);
3168 list_for_each_entry(s, &slab_caches, list)
3169 s->cpu_slab[cpu] = alloc_kmem_cache_cpu(s, cpu,
3170 GFP_KERNEL);
3171 up_read(&slub_lock);
3172 break;
3173
Christoph Lameter81819f02007-05-06 14:49:36 -07003174 case CPU_UP_CANCELED:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07003175 case CPU_UP_CANCELED_FROZEN:
Christoph Lameter81819f02007-05-06 14:49:36 -07003176 case CPU_DEAD:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07003177 case CPU_DEAD_FROZEN:
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07003178 down_read(&slub_lock);
3179 list_for_each_entry(s, &slab_caches, list) {
Christoph Lameter4c93c3552007-10-16 01:26:08 -07003180 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
3181
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07003182 local_irq_save(flags);
3183 __flush_cpu_slab(s, cpu);
3184 local_irq_restore(flags);
Christoph Lameter4c93c3552007-10-16 01:26:08 -07003185 free_kmem_cache_cpu(c, cpu);
3186 s->cpu_slab[cpu] = NULL;
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07003187 }
3188 up_read(&slub_lock);
Christoph Lameter81819f02007-05-06 14:49:36 -07003189 break;
3190 default:
3191 break;
3192 }
3193 return NOTIFY_OK;
3194}
3195
Pekka Enberg06428782008-01-07 23:20:27 -08003196static struct notifier_block __cpuinitdata slab_notifier = {
Ingo Molnar3adbefe2008-02-05 17:57:39 -08003197 .notifier_call = slab_cpuup_callback
Pekka Enberg06428782008-01-07 23:20:27 -08003198};
Christoph Lameter81819f02007-05-06 14:49:36 -07003199
3200#endif
3201
Christoph Lameter81819f02007-05-06 14:49:36 -07003202void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, void *caller)
3203{
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07003204 struct kmem_cache *s;
3205
Christoph Lameter331dc552008-02-14 14:28:09 -08003206 if (unlikely(size > PAGE_SIZE))
Pekka Enbergeada35e2008-02-11 22:47:46 +02003207 return kmalloc_large(size, gfpflags);
3208
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07003209 s = get_slab(size, gfpflags);
Christoph Lameter81819f02007-05-06 14:49:36 -07003210
Satyam Sharma2408c552007-10-16 01:24:44 -07003211 if (unlikely(ZERO_OR_NULL_PTR(s)))
Christoph Lameter6cb8f912007-07-17 04:03:22 -07003212 return s;
Christoph Lameter81819f02007-05-06 14:49:36 -07003213
Christoph Lameterce15fea2007-07-17 04:03:28 -07003214 return slab_alloc(s, gfpflags, -1, caller);
Christoph Lameter81819f02007-05-06 14:49:36 -07003215}
3216
3217void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
3218 int node, void *caller)
3219{
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07003220 struct kmem_cache *s;
3221
Christoph Lameter331dc552008-02-14 14:28:09 -08003222 if (unlikely(size > PAGE_SIZE))
Christoph Lameterf619cfe2008-03-01 13:56:40 -08003223 return kmalloc_large_node(size, gfpflags, node);
Pekka Enbergeada35e2008-02-11 22:47:46 +02003224
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07003225 s = get_slab(size, gfpflags);
Christoph Lameter81819f02007-05-06 14:49:36 -07003226
Satyam Sharma2408c552007-10-16 01:24:44 -07003227 if (unlikely(ZERO_OR_NULL_PTR(s)))
Christoph Lameter6cb8f912007-07-17 04:03:22 -07003228 return s;
Christoph Lameter81819f02007-05-06 14:49:36 -07003229
Christoph Lameterce15fea2007-07-17 04:03:28 -07003230 return slab_alloc(s, gfpflags, node, caller);
Christoph Lameter81819f02007-05-06 14:49:36 -07003231}
3232
Christoph Lameterf6acb632008-04-29 16:16:06 -07003233#ifdef CONFIG_SLUB_DEBUG
Christoph Lameter205ab992008-04-14 19:11:40 +03003234static unsigned long count_partial(struct kmem_cache_node *n,
3235 int (*get_count)(struct page *))
Christoph Lameter5b06c8532008-04-14 18:51:34 +03003236{
3237 unsigned long flags;
3238 unsigned long x = 0;
3239 struct page *page;
3240
3241 spin_lock_irqsave(&n->list_lock, flags);
3242 list_for_each_entry(page, &n->partial, lru)
Christoph Lameter205ab992008-04-14 19:11:40 +03003243 x += get_count(page);
Christoph Lameter5b06c8532008-04-14 18:51:34 +03003244 spin_unlock_irqrestore(&n->list_lock, flags);
3245 return x;
3246}
Christoph Lameter205ab992008-04-14 19:11:40 +03003247
3248static int count_inuse(struct page *page)
3249{
3250 return page->inuse;
3251}
3252
3253static int count_total(struct page *page)
3254{
3255 return page->objects;
3256}
3257
3258static int count_free(struct page *page)
3259{
3260 return page->objects - page->inuse;
3261}
Christoph Lameter5b06c8532008-04-14 18:51:34 +03003262
Christoph Lameter434e2452007-07-17 04:03:30 -07003263static int validate_slab(struct kmem_cache *s, struct page *page,
3264 unsigned long *map)
Christoph Lameter53e15af2007-05-06 14:49:43 -07003265{
3266 void *p;
Christoph Lametera973e9d2008-03-01 13:40:44 -08003267 void *addr = page_address(page);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003268
3269 if (!check_slab(s, page) ||
3270 !on_freelist(s, page, NULL))
3271 return 0;
3272
3273 /* Now we know that a valid freelist exists */
Christoph Lameter39b26462008-04-14 19:11:30 +03003274 bitmap_zero(map, page->objects);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003275
Christoph Lameter7656c722007-05-09 02:32:40 -07003276 for_each_free_object(p, s, page->freelist) {
3277 set_bit(slab_index(p, s, addr), map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003278 if (!check_object(s, page, p, 0))
3279 return 0;
3280 }
3281
Christoph Lameter224a88b2008-04-14 19:11:31 +03003282 for_each_object(p, s, addr, page->objects)
Christoph Lameter7656c722007-05-09 02:32:40 -07003283 if (!test_bit(slab_index(p, s, addr), map))
Christoph Lameter53e15af2007-05-06 14:49:43 -07003284 if (!check_object(s, page, p, 1))
3285 return 0;
3286 return 1;
3287}
3288
Christoph Lameter434e2452007-07-17 04:03:30 -07003289static void validate_slab_slab(struct kmem_cache *s, struct page *page,
3290 unsigned long *map)
Christoph Lameter53e15af2007-05-06 14:49:43 -07003291{
3292 if (slab_trylock(page)) {
Christoph Lameter434e2452007-07-17 04:03:30 -07003293 validate_slab(s, page, map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003294 slab_unlock(page);
3295 } else
3296 printk(KERN_INFO "SLUB %s: Skipped busy slab 0x%p\n",
3297 s->name, page);
3298
3299 if (s->flags & DEBUG_DEFAULT_FLAGS) {
Andy Whitcroft8a380822008-07-23 21:27:18 -07003300 if (!PageSlubDebug(page))
3301 printk(KERN_ERR "SLUB %s: SlubDebug not set "
Christoph Lameter53e15af2007-05-06 14:49:43 -07003302 "on slab 0x%p\n", s->name, page);
3303 } else {
Andy Whitcroft8a380822008-07-23 21:27:18 -07003304 if (PageSlubDebug(page))
3305 printk(KERN_ERR "SLUB %s: SlubDebug set on "
Christoph Lameter53e15af2007-05-06 14:49:43 -07003306 "slab 0x%p\n", s->name, page);
3307 }
3308}
3309
Christoph Lameter434e2452007-07-17 04:03:30 -07003310static int validate_slab_node(struct kmem_cache *s,
3311 struct kmem_cache_node *n, unsigned long *map)
Christoph Lameter53e15af2007-05-06 14:49:43 -07003312{
3313 unsigned long count = 0;
3314 struct page *page;
3315 unsigned long flags;
3316
3317 spin_lock_irqsave(&n->list_lock, flags);
3318
3319 list_for_each_entry(page, &n->partial, lru) {
Christoph Lameter434e2452007-07-17 04:03:30 -07003320 validate_slab_slab(s, page, map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003321 count++;
3322 }
3323 if (count != n->nr_partial)
3324 printk(KERN_ERR "SLUB %s: %ld partial slabs counted but "
3325 "counter=%ld\n", s->name, count, n->nr_partial);
3326
3327 if (!(s->flags & SLAB_STORE_USER))
3328 goto out;
3329
3330 list_for_each_entry(page, &n->full, lru) {
Christoph Lameter434e2452007-07-17 04:03:30 -07003331 validate_slab_slab(s, page, map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003332 count++;
3333 }
3334 if (count != atomic_long_read(&n->nr_slabs))
3335 printk(KERN_ERR "SLUB: %s %ld slabs counted but "
3336 "counter=%ld\n", s->name, count,
3337 atomic_long_read(&n->nr_slabs));
3338
3339out:
3340 spin_unlock_irqrestore(&n->list_lock, flags);
3341 return count;
3342}
3343
Christoph Lameter434e2452007-07-17 04:03:30 -07003344static long validate_slab_cache(struct kmem_cache *s)
Christoph Lameter53e15af2007-05-06 14:49:43 -07003345{
3346 int node;
3347 unsigned long count = 0;
Christoph Lameter205ab992008-04-14 19:11:40 +03003348 unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) *
Christoph Lameter434e2452007-07-17 04:03:30 -07003349 sizeof(unsigned long), GFP_KERNEL);
3350
3351 if (!map)
3352 return -ENOMEM;
Christoph Lameter53e15af2007-05-06 14:49:43 -07003353
3354 flush_all(s);
Christoph Lameterf64dc582007-10-16 01:25:33 -07003355 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter53e15af2007-05-06 14:49:43 -07003356 struct kmem_cache_node *n = get_node(s, node);
3357
Christoph Lameter434e2452007-07-17 04:03:30 -07003358 count += validate_slab_node(s, n, map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003359 }
Christoph Lameter434e2452007-07-17 04:03:30 -07003360 kfree(map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003361 return count;
3362}
3363
Christoph Lameterb3459702007-05-09 02:32:41 -07003364#ifdef SLUB_RESILIENCY_TEST
3365static void resiliency_test(void)
3366{
3367 u8 *p;
3368
3369 printk(KERN_ERR "SLUB resiliency testing\n");
3370 printk(KERN_ERR "-----------------------\n");
3371 printk(KERN_ERR "A. Corruption after allocation\n");
3372
3373 p = kzalloc(16, GFP_KERNEL);
3374 p[16] = 0x12;
3375 printk(KERN_ERR "\n1. kmalloc-16: Clobber Redzone/next pointer"
3376 " 0x12->0x%p\n\n", p + 16);
3377
3378 validate_slab_cache(kmalloc_caches + 4);
3379
3380 /* Hmmm... The next two are dangerous */
3381 p = kzalloc(32, GFP_KERNEL);
3382 p[32 + sizeof(void *)] = 0x34;
3383 printk(KERN_ERR "\n2. kmalloc-32: Clobber next pointer/next slab"
Ingo Molnar3adbefe2008-02-05 17:57:39 -08003384 " 0x34 -> -0x%p\n", p);
3385 printk(KERN_ERR
3386 "If allocated object is overwritten then not detectable\n\n");
Christoph Lameterb3459702007-05-09 02:32:41 -07003387
3388 validate_slab_cache(kmalloc_caches + 5);
3389 p = kzalloc(64, GFP_KERNEL);
3390 p += 64 + (get_cycles() & 0xff) * sizeof(void *);
3391 *p = 0x56;
3392 printk(KERN_ERR "\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n",
3393 p);
Ingo Molnar3adbefe2008-02-05 17:57:39 -08003394 printk(KERN_ERR
3395 "If allocated object is overwritten then not detectable\n\n");
Christoph Lameterb3459702007-05-09 02:32:41 -07003396 validate_slab_cache(kmalloc_caches + 6);
3397
3398 printk(KERN_ERR "\nB. Corruption after free\n");
3399 p = kzalloc(128, GFP_KERNEL);
3400 kfree(p);
3401 *p = 0x78;
3402 printk(KERN_ERR "1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p);
3403 validate_slab_cache(kmalloc_caches + 7);
3404
3405 p = kzalloc(256, GFP_KERNEL);
3406 kfree(p);
3407 p[50] = 0x9a;
Ingo Molnar3adbefe2008-02-05 17:57:39 -08003408 printk(KERN_ERR "\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n",
3409 p);
Christoph Lameterb3459702007-05-09 02:32:41 -07003410 validate_slab_cache(kmalloc_caches + 8);
3411
3412 p = kzalloc(512, GFP_KERNEL);
3413 kfree(p);
3414 p[512] = 0xab;
3415 printk(KERN_ERR "\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p);
3416 validate_slab_cache(kmalloc_caches + 9);
3417}
3418#else
3419static void resiliency_test(void) {};
3420#endif
3421
Christoph Lameter88a420e2007-05-06 14:49:45 -07003422/*
Christoph Lameter672bba32007-05-09 02:32:39 -07003423 * Generate lists of code addresses where slabcache objects are allocated
Christoph Lameter88a420e2007-05-06 14:49:45 -07003424 * and freed.
3425 */
3426
3427struct location {
3428 unsigned long count;
3429 void *addr;
Christoph Lameter45edfa52007-05-09 02:32:45 -07003430 long long sum_time;
3431 long min_time;
3432 long max_time;
3433 long min_pid;
3434 long max_pid;
3435 cpumask_t cpus;
3436 nodemask_t nodes;
Christoph Lameter88a420e2007-05-06 14:49:45 -07003437};
3438
3439struct loc_track {
3440 unsigned long max;
3441 unsigned long count;
3442 struct location *loc;
3443};
3444
3445static void free_loc_track(struct loc_track *t)
3446{
3447 if (t->max)
3448 free_pages((unsigned long)t->loc,
3449 get_order(sizeof(struct location) * t->max));
3450}
3451
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003452static int alloc_loc_track(struct loc_track *t, unsigned long max, gfp_t flags)
Christoph Lameter88a420e2007-05-06 14:49:45 -07003453{
3454 struct location *l;
3455 int order;
3456
Christoph Lameter88a420e2007-05-06 14:49:45 -07003457 order = get_order(sizeof(struct location) * max);
3458
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003459 l = (void *)__get_free_pages(flags, order);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003460 if (!l)
3461 return 0;
3462
3463 if (t->count) {
3464 memcpy(l, t->loc, sizeof(struct location) * t->count);
3465 free_loc_track(t);
3466 }
3467 t->max = max;
3468 t->loc = l;
3469 return 1;
3470}
3471
3472static int add_location(struct loc_track *t, struct kmem_cache *s,
Christoph Lameter45edfa52007-05-09 02:32:45 -07003473 const struct track *track)
Christoph Lameter88a420e2007-05-06 14:49:45 -07003474{
3475 long start, end, pos;
3476 struct location *l;
3477 void *caddr;
Christoph Lameter45edfa52007-05-09 02:32:45 -07003478 unsigned long age = jiffies - track->when;
Christoph Lameter88a420e2007-05-06 14:49:45 -07003479
3480 start = -1;
3481 end = t->count;
3482
3483 for ( ; ; ) {
3484 pos = start + (end - start + 1) / 2;
3485
3486 /*
3487 * There is nothing at "end". If we end up there
3488 * we need to add something to before end.
3489 */
3490 if (pos == end)
3491 break;
3492
3493 caddr = t->loc[pos].addr;
Christoph Lameter45edfa52007-05-09 02:32:45 -07003494 if (track->addr == caddr) {
3495
3496 l = &t->loc[pos];
3497 l->count++;
3498 if (track->when) {
3499 l->sum_time += age;
3500 if (age < l->min_time)
3501 l->min_time = age;
3502 if (age > l->max_time)
3503 l->max_time = age;
3504
3505 if (track->pid < l->min_pid)
3506 l->min_pid = track->pid;
3507 if (track->pid > l->max_pid)
3508 l->max_pid = track->pid;
3509
3510 cpu_set(track->cpu, l->cpus);
3511 }
3512 node_set(page_to_nid(virt_to_page(track)), l->nodes);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003513 return 1;
3514 }
3515
Christoph Lameter45edfa52007-05-09 02:32:45 -07003516 if (track->addr < caddr)
Christoph Lameter88a420e2007-05-06 14:49:45 -07003517 end = pos;
3518 else
3519 start = pos;
3520 }
3521
3522 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07003523 * Not found. Insert new tracking element.
Christoph Lameter88a420e2007-05-06 14:49:45 -07003524 */
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003525 if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max, GFP_ATOMIC))
Christoph Lameter88a420e2007-05-06 14:49:45 -07003526 return 0;
3527
3528 l = t->loc + pos;
3529 if (pos < t->count)
3530 memmove(l + 1, l,
3531 (t->count - pos) * sizeof(struct location));
3532 t->count++;
3533 l->count = 1;
Christoph Lameter45edfa52007-05-09 02:32:45 -07003534 l->addr = track->addr;
3535 l->sum_time = age;
3536 l->min_time = age;
3537 l->max_time = age;
3538 l->min_pid = track->pid;
3539 l->max_pid = track->pid;
3540 cpus_clear(l->cpus);
3541 cpu_set(track->cpu, l->cpus);
3542 nodes_clear(l->nodes);
3543 node_set(page_to_nid(virt_to_page(track)), l->nodes);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003544 return 1;
3545}
3546
3547static void process_slab(struct loc_track *t, struct kmem_cache *s,
3548 struct page *page, enum track_item alloc)
3549{
Christoph Lametera973e9d2008-03-01 13:40:44 -08003550 void *addr = page_address(page);
Christoph Lameter39b26462008-04-14 19:11:30 +03003551 DECLARE_BITMAP(map, page->objects);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003552 void *p;
3553
Christoph Lameter39b26462008-04-14 19:11:30 +03003554 bitmap_zero(map, page->objects);
Christoph Lameter7656c722007-05-09 02:32:40 -07003555 for_each_free_object(p, s, page->freelist)
3556 set_bit(slab_index(p, s, addr), map);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003557
Christoph Lameter224a88b2008-04-14 19:11:31 +03003558 for_each_object(p, s, addr, page->objects)
Christoph Lameter45edfa52007-05-09 02:32:45 -07003559 if (!test_bit(slab_index(p, s, addr), map))
3560 add_location(t, s, get_track(s, p, alloc));
Christoph Lameter88a420e2007-05-06 14:49:45 -07003561}
3562
3563static int list_locations(struct kmem_cache *s, char *buf,
3564 enum track_item alloc)
3565{
Harvey Harrisone374d482008-01-31 15:20:50 -08003566 int len = 0;
Christoph Lameter88a420e2007-05-06 14:49:45 -07003567 unsigned long i;
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003568 struct loc_track t = { 0, 0, NULL };
Christoph Lameter88a420e2007-05-06 14:49:45 -07003569 int node;
3570
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003571 if (!alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location),
Andrew Mortonea3061d2007-10-16 01:26:09 -07003572 GFP_TEMPORARY))
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003573 return sprintf(buf, "Out of memory\n");
Christoph Lameter88a420e2007-05-06 14:49:45 -07003574
3575 /* Push back cpu slabs */
3576 flush_all(s);
3577
Christoph Lameterf64dc582007-10-16 01:25:33 -07003578 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter88a420e2007-05-06 14:49:45 -07003579 struct kmem_cache_node *n = get_node(s, node);
3580 unsigned long flags;
3581 struct page *page;
3582
Christoph Lameter9e869432007-08-22 14:01:56 -07003583 if (!atomic_long_read(&n->nr_slabs))
Christoph Lameter88a420e2007-05-06 14:49:45 -07003584 continue;
3585
3586 spin_lock_irqsave(&n->list_lock, flags);
3587 list_for_each_entry(page, &n->partial, lru)
3588 process_slab(&t, s, page, alloc);
3589 list_for_each_entry(page, &n->full, lru)
3590 process_slab(&t, s, page, alloc);
3591 spin_unlock_irqrestore(&n->list_lock, flags);
3592 }
3593
3594 for (i = 0; i < t.count; i++) {
Christoph Lameter45edfa52007-05-09 02:32:45 -07003595 struct location *l = &t.loc[i];
Christoph Lameter88a420e2007-05-06 14:49:45 -07003596
Harvey Harrisone374d482008-01-31 15:20:50 -08003597 if (len > PAGE_SIZE - 100)
Christoph Lameter88a420e2007-05-06 14:49:45 -07003598 break;
Harvey Harrisone374d482008-01-31 15:20:50 -08003599 len += sprintf(buf + len, "%7ld ", l->count);
Christoph Lameter45edfa52007-05-09 02:32:45 -07003600
3601 if (l->addr)
Harvey Harrisone374d482008-01-31 15:20:50 -08003602 len += sprint_symbol(buf + len, (unsigned long)l->addr);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003603 else
Harvey Harrisone374d482008-01-31 15:20:50 -08003604 len += sprintf(buf + len, "<not-available>");
Christoph Lameter45edfa52007-05-09 02:32:45 -07003605
3606 if (l->sum_time != l->min_time) {
Harvey Harrisone374d482008-01-31 15:20:50 -08003607 len += sprintf(buf + len, " age=%ld/%ld/%ld",
Roman Zippelf8bd2252008-05-01 04:34:31 -07003608 l->min_time,
3609 (long)div_u64(l->sum_time, l->count),
3610 l->max_time);
Christoph Lameter45edfa52007-05-09 02:32:45 -07003611 } else
Harvey Harrisone374d482008-01-31 15:20:50 -08003612 len += sprintf(buf + len, " age=%ld",
Christoph Lameter45edfa52007-05-09 02:32:45 -07003613 l->min_time);
3614
3615 if (l->min_pid != l->max_pid)
Harvey Harrisone374d482008-01-31 15:20:50 -08003616 len += sprintf(buf + len, " pid=%ld-%ld",
Christoph Lameter45edfa52007-05-09 02:32:45 -07003617 l->min_pid, l->max_pid);
3618 else
Harvey Harrisone374d482008-01-31 15:20:50 -08003619 len += sprintf(buf + len, " pid=%ld",
Christoph Lameter45edfa52007-05-09 02:32:45 -07003620 l->min_pid);
3621
Christoph Lameter84966342007-06-23 17:16:32 -07003622 if (num_online_cpus() > 1 && !cpus_empty(l->cpus) &&
Harvey Harrisone374d482008-01-31 15:20:50 -08003623 len < PAGE_SIZE - 60) {
3624 len += sprintf(buf + len, " cpus=");
3625 len += cpulist_scnprintf(buf + len, PAGE_SIZE - len - 50,
Christoph Lameter45edfa52007-05-09 02:32:45 -07003626 l->cpus);
3627 }
3628
Christoph Lameter84966342007-06-23 17:16:32 -07003629 if (num_online_nodes() > 1 && !nodes_empty(l->nodes) &&
Harvey Harrisone374d482008-01-31 15:20:50 -08003630 len < PAGE_SIZE - 60) {
3631 len += sprintf(buf + len, " nodes=");
3632 len += nodelist_scnprintf(buf + len, PAGE_SIZE - len - 50,
Christoph Lameter45edfa52007-05-09 02:32:45 -07003633 l->nodes);
3634 }
3635
Harvey Harrisone374d482008-01-31 15:20:50 -08003636 len += sprintf(buf + len, "\n");
Christoph Lameter88a420e2007-05-06 14:49:45 -07003637 }
3638
3639 free_loc_track(&t);
3640 if (!t.count)
Harvey Harrisone374d482008-01-31 15:20:50 -08003641 len += sprintf(buf, "No data\n");
3642 return len;
Christoph Lameter88a420e2007-05-06 14:49:45 -07003643}
3644
Christoph Lameter81819f02007-05-06 14:49:36 -07003645enum slab_stat_type {
Christoph Lameter205ab992008-04-14 19:11:40 +03003646 SL_ALL, /* All slabs */
3647 SL_PARTIAL, /* Only partially allocated slabs */
3648 SL_CPU, /* Only slabs used for cpu caches */
3649 SL_OBJECTS, /* Determine allocated objects not slabs */
3650 SL_TOTAL /* Determine object capacity not slabs */
Christoph Lameter81819f02007-05-06 14:49:36 -07003651};
3652
Christoph Lameter205ab992008-04-14 19:11:40 +03003653#define SO_ALL (1 << SL_ALL)
Christoph Lameter81819f02007-05-06 14:49:36 -07003654#define SO_PARTIAL (1 << SL_PARTIAL)
3655#define SO_CPU (1 << SL_CPU)
3656#define SO_OBJECTS (1 << SL_OBJECTS)
Christoph Lameter205ab992008-04-14 19:11:40 +03003657#define SO_TOTAL (1 << SL_TOTAL)
Christoph Lameter81819f02007-05-06 14:49:36 -07003658
Cyrill Gorcunov62e5c4b2008-03-02 23:28:24 +03003659static ssize_t show_slab_objects(struct kmem_cache *s,
3660 char *buf, unsigned long flags)
Christoph Lameter81819f02007-05-06 14:49:36 -07003661{
3662 unsigned long total = 0;
Christoph Lameter81819f02007-05-06 14:49:36 -07003663 int node;
3664 int x;
3665 unsigned long *nodes;
3666 unsigned long *per_cpu;
3667
3668 nodes = kzalloc(2 * sizeof(unsigned long) * nr_node_ids, GFP_KERNEL);
Cyrill Gorcunov62e5c4b2008-03-02 23:28:24 +03003669 if (!nodes)
3670 return -ENOMEM;
Christoph Lameter81819f02007-05-06 14:49:36 -07003671 per_cpu = nodes + nr_node_ids;
3672
Christoph Lameter205ab992008-04-14 19:11:40 +03003673 if (flags & SO_CPU) {
3674 int cpu;
Christoph Lameter81819f02007-05-06 14:49:36 -07003675
Christoph Lameter205ab992008-04-14 19:11:40 +03003676 for_each_possible_cpu(cpu) {
3677 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
Christoph Lameterdfb4f092007-10-16 01:26:05 -07003678
Christoph Lameter205ab992008-04-14 19:11:40 +03003679 if (!c || c->node < 0)
3680 continue;
3681
3682 if (c->page) {
3683 if (flags & SO_TOTAL)
3684 x = c->page->objects;
3685 else if (flags & SO_OBJECTS)
3686 x = c->page->inuse;
Christoph Lameter81819f02007-05-06 14:49:36 -07003687 else
3688 x = 1;
Christoph Lameter205ab992008-04-14 19:11:40 +03003689
Christoph Lameter81819f02007-05-06 14:49:36 -07003690 total += x;
Christoph Lameter205ab992008-04-14 19:11:40 +03003691 nodes[c->node] += x;
Christoph Lameter81819f02007-05-06 14:49:36 -07003692 }
Christoph Lameter205ab992008-04-14 19:11:40 +03003693 per_cpu[c->node]++;
Christoph Lameter81819f02007-05-06 14:49:36 -07003694 }
3695 }
3696
Christoph Lameter205ab992008-04-14 19:11:40 +03003697 if (flags & SO_ALL) {
3698 for_each_node_state(node, N_NORMAL_MEMORY) {
3699 struct kmem_cache_node *n = get_node(s, node);
Christoph Lameter81819f02007-05-06 14:49:36 -07003700
Christoph Lameter205ab992008-04-14 19:11:40 +03003701 if (flags & SO_TOTAL)
3702 x = atomic_long_read(&n->total_objects);
3703 else if (flags & SO_OBJECTS)
3704 x = atomic_long_read(&n->total_objects) -
3705 count_partial(n, count_free);
3706
3707 else
3708 x = atomic_long_read(&n->nr_slabs);
3709 total += x;
3710 nodes[node] += x;
3711 }
3712
3713 } else if (flags & SO_PARTIAL) {
3714 for_each_node_state(node, N_NORMAL_MEMORY) {
3715 struct kmem_cache_node *n = get_node(s, node);
3716
3717 if (flags & SO_TOTAL)
3718 x = count_partial(n, count_total);
3719 else if (flags & SO_OBJECTS)
3720 x = count_partial(n, count_inuse);
Christoph Lameter81819f02007-05-06 14:49:36 -07003721 else
3722 x = n->nr_partial;
3723 total += x;
3724 nodes[node] += x;
3725 }
Christoph Lameter81819f02007-05-06 14:49:36 -07003726 }
Christoph Lameter81819f02007-05-06 14:49:36 -07003727 x = sprintf(buf, "%lu", total);
3728#ifdef CONFIG_NUMA
Christoph Lameterf64dc582007-10-16 01:25:33 -07003729 for_each_node_state(node, N_NORMAL_MEMORY)
Christoph Lameter81819f02007-05-06 14:49:36 -07003730 if (nodes[node])
3731 x += sprintf(buf + x, " N%d=%lu",
3732 node, nodes[node]);
3733#endif
3734 kfree(nodes);
3735 return x + sprintf(buf + x, "\n");
3736}
3737
3738static int any_slab_objects(struct kmem_cache *s)
3739{
3740 int node;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07003741
3742 for_each_online_node(node) {
Christoph Lameter81819f02007-05-06 14:49:36 -07003743 struct kmem_cache_node *n = get_node(s, node);
3744
Christoph Lameterdfb4f092007-10-16 01:26:05 -07003745 if (!n)
3746 continue;
3747
Benjamin Herrenschmidt4ea33e22008-05-06 20:42:39 -07003748 if (atomic_long_read(&n->total_objects))
Christoph Lameter81819f02007-05-06 14:49:36 -07003749 return 1;
3750 }
3751 return 0;
3752}
3753
3754#define to_slab_attr(n) container_of(n, struct slab_attribute, attr)
3755#define to_slab(n) container_of(n, struct kmem_cache, kobj);
3756
3757struct slab_attribute {
3758 struct attribute attr;
3759 ssize_t (*show)(struct kmem_cache *s, char *buf);
3760 ssize_t (*store)(struct kmem_cache *s, const char *x, size_t count);
3761};
3762
3763#define SLAB_ATTR_RO(_name) \
3764 static struct slab_attribute _name##_attr = __ATTR_RO(_name)
3765
3766#define SLAB_ATTR(_name) \
3767 static struct slab_attribute _name##_attr = \
3768 __ATTR(_name, 0644, _name##_show, _name##_store)
3769
Christoph Lameter81819f02007-05-06 14:49:36 -07003770static ssize_t slab_size_show(struct kmem_cache *s, char *buf)
3771{
3772 return sprintf(buf, "%d\n", s->size);
3773}
3774SLAB_ATTR_RO(slab_size);
3775
3776static ssize_t align_show(struct kmem_cache *s, char *buf)
3777{
3778 return sprintf(buf, "%d\n", s->align);
3779}
3780SLAB_ATTR_RO(align);
3781
3782static ssize_t object_size_show(struct kmem_cache *s, char *buf)
3783{
3784 return sprintf(buf, "%d\n", s->objsize);
3785}
3786SLAB_ATTR_RO(object_size);
3787
3788static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf)
3789{
Christoph Lameter834f3d12008-04-14 19:11:31 +03003790 return sprintf(buf, "%d\n", oo_objects(s->oo));
Christoph Lameter81819f02007-05-06 14:49:36 -07003791}
3792SLAB_ATTR_RO(objs_per_slab);
3793
Christoph Lameter06b285d2008-04-14 19:11:41 +03003794static ssize_t order_store(struct kmem_cache *s,
3795 const char *buf, size_t length)
3796{
Christoph Lameter0121c6192008-04-29 16:11:12 -07003797 unsigned long order;
3798 int err;
3799
3800 err = strict_strtoul(buf, 10, &order);
3801 if (err)
3802 return err;
Christoph Lameter06b285d2008-04-14 19:11:41 +03003803
3804 if (order > slub_max_order || order < slub_min_order)
3805 return -EINVAL;
3806
3807 calculate_sizes(s, order);
3808 return length;
3809}
3810
Christoph Lameter81819f02007-05-06 14:49:36 -07003811static ssize_t order_show(struct kmem_cache *s, char *buf)
3812{
Christoph Lameter834f3d12008-04-14 19:11:31 +03003813 return sprintf(buf, "%d\n", oo_order(s->oo));
Christoph Lameter81819f02007-05-06 14:49:36 -07003814}
Christoph Lameter06b285d2008-04-14 19:11:41 +03003815SLAB_ATTR(order);
Christoph Lameter81819f02007-05-06 14:49:36 -07003816
3817static ssize_t ctor_show(struct kmem_cache *s, char *buf)
3818{
3819 if (s->ctor) {
3820 int n = sprint_symbol(buf, (unsigned long)s->ctor);
3821
3822 return n + sprintf(buf + n, "\n");
3823 }
3824 return 0;
3825}
3826SLAB_ATTR_RO(ctor);
3827
Christoph Lameter81819f02007-05-06 14:49:36 -07003828static ssize_t aliases_show(struct kmem_cache *s, char *buf)
3829{
3830 return sprintf(buf, "%d\n", s->refcount - 1);
3831}
3832SLAB_ATTR_RO(aliases);
3833
3834static ssize_t slabs_show(struct kmem_cache *s, char *buf)
3835{
Christoph Lameter205ab992008-04-14 19:11:40 +03003836 return show_slab_objects(s, buf, SO_ALL);
Christoph Lameter81819f02007-05-06 14:49:36 -07003837}
3838SLAB_ATTR_RO(slabs);
3839
3840static ssize_t partial_show(struct kmem_cache *s, char *buf)
3841{
Christoph Lameterd9acf4b2008-02-15 15:22:21 -08003842 return show_slab_objects(s, buf, SO_PARTIAL);
Christoph Lameter81819f02007-05-06 14:49:36 -07003843}
3844SLAB_ATTR_RO(partial);
3845
3846static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf)
3847{
Christoph Lameterd9acf4b2008-02-15 15:22:21 -08003848 return show_slab_objects(s, buf, SO_CPU);
Christoph Lameter81819f02007-05-06 14:49:36 -07003849}
3850SLAB_ATTR_RO(cpu_slabs);
3851
3852static ssize_t objects_show(struct kmem_cache *s, char *buf)
3853{
Christoph Lameter205ab992008-04-14 19:11:40 +03003854 return show_slab_objects(s, buf, SO_ALL|SO_OBJECTS);
Christoph Lameter81819f02007-05-06 14:49:36 -07003855}
3856SLAB_ATTR_RO(objects);
3857
Christoph Lameter205ab992008-04-14 19:11:40 +03003858static ssize_t objects_partial_show(struct kmem_cache *s, char *buf)
3859{
3860 return show_slab_objects(s, buf, SO_PARTIAL|SO_OBJECTS);
3861}
3862SLAB_ATTR_RO(objects_partial);
3863
3864static ssize_t total_objects_show(struct kmem_cache *s, char *buf)
3865{
3866 return show_slab_objects(s, buf, SO_ALL|SO_TOTAL);
3867}
3868SLAB_ATTR_RO(total_objects);
3869
Christoph Lameter81819f02007-05-06 14:49:36 -07003870static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf)
3871{
3872 return sprintf(buf, "%d\n", !!(s->flags & SLAB_DEBUG_FREE));
3873}
3874
3875static ssize_t sanity_checks_store(struct kmem_cache *s,
3876 const char *buf, size_t length)
3877{
3878 s->flags &= ~SLAB_DEBUG_FREE;
3879 if (buf[0] == '1')
3880 s->flags |= SLAB_DEBUG_FREE;
3881 return length;
3882}
3883SLAB_ATTR(sanity_checks);
3884
3885static ssize_t trace_show(struct kmem_cache *s, char *buf)
3886{
3887 return sprintf(buf, "%d\n", !!(s->flags & SLAB_TRACE));
3888}
3889
3890static ssize_t trace_store(struct kmem_cache *s, const char *buf,
3891 size_t length)
3892{
3893 s->flags &= ~SLAB_TRACE;
3894 if (buf[0] == '1')
3895 s->flags |= SLAB_TRACE;
3896 return length;
3897}
3898SLAB_ATTR(trace);
3899
3900static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf)
3901{
3902 return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT));
3903}
3904
3905static ssize_t reclaim_account_store(struct kmem_cache *s,
3906 const char *buf, size_t length)
3907{
3908 s->flags &= ~SLAB_RECLAIM_ACCOUNT;
3909 if (buf[0] == '1')
3910 s->flags |= SLAB_RECLAIM_ACCOUNT;
3911 return length;
3912}
3913SLAB_ATTR(reclaim_account);
3914
3915static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf)
3916{
Christoph Lameter5af60832007-05-06 14:49:56 -07003917 return sprintf(buf, "%d\n", !!(s->flags & SLAB_HWCACHE_ALIGN));
Christoph Lameter81819f02007-05-06 14:49:36 -07003918}
3919SLAB_ATTR_RO(hwcache_align);
3920
3921#ifdef CONFIG_ZONE_DMA
3922static ssize_t cache_dma_show(struct kmem_cache *s, char *buf)
3923{
3924 return sprintf(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA));
3925}
3926SLAB_ATTR_RO(cache_dma);
3927#endif
3928
3929static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf)
3930{
3931 return sprintf(buf, "%d\n", !!(s->flags & SLAB_DESTROY_BY_RCU));
3932}
3933SLAB_ATTR_RO(destroy_by_rcu);
3934
3935static ssize_t red_zone_show(struct kmem_cache *s, char *buf)
3936{
3937 return sprintf(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE));
3938}
3939
3940static ssize_t red_zone_store(struct kmem_cache *s,
3941 const char *buf, size_t length)
3942{
3943 if (any_slab_objects(s))
3944 return -EBUSY;
3945
3946 s->flags &= ~SLAB_RED_ZONE;
3947 if (buf[0] == '1')
3948 s->flags |= SLAB_RED_ZONE;
Christoph Lameter06b285d2008-04-14 19:11:41 +03003949 calculate_sizes(s, -1);
Christoph Lameter81819f02007-05-06 14:49:36 -07003950 return length;
3951}
3952SLAB_ATTR(red_zone);
3953
3954static ssize_t poison_show(struct kmem_cache *s, char *buf)
3955{
3956 return sprintf(buf, "%d\n", !!(s->flags & SLAB_POISON));
3957}
3958
3959static ssize_t poison_store(struct kmem_cache *s,
3960 const char *buf, size_t length)
3961{
3962 if (any_slab_objects(s))
3963 return -EBUSY;
3964
3965 s->flags &= ~SLAB_POISON;
3966 if (buf[0] == '1')
3967 s->flags |= SLAB_POISON;
Christoph Lameter06b285d2008-04-14 19:11:41 +03003968 calculate_sizes(s, -1);
Christoph Lameter81819f02007-05-06 14:49:36 -07003969 return length;
3970}
3971SLAB_ATTR(poison);
3972
3973static ssize_t store_user_show(struct kmem_cache *s, char *buf)
3974{
3975 return sprintf(buf, "%d\n", !!(s->flags & SLAB_STORE_USER));
3976}
3977
3978static ssize_t store_user_store(struct kmem_cache *s,
3979 const char *buf, size_t length)
3980{
3981 if (any_slab_objects(s))
3982 return -EBUSY;
3983
3984 s->flags &= ~SLAB_STORE_USER;
3985 if (buf[0] == '1')
3986 s->flags |= SLAB_STORE_USER;
Christoph Lameter06b285d2008-04-14 19:11:41 +03003987 calculate_sizes(s, -1);
Christoph Lameter81819f02007-05-06 14:49:36 -07003988 return length;
3989}
3990SLAB_ATTR(store_user);
3991
Christoph Lameter53e15af2007-05-06 14:49:43 -07003992static ssize_t validate_show(struct kmem_cache *s, char *buf)
3993{
3994 return 0;
3995}
3996
3997static ssize_t validate_store(struct kmem_cache *s,
3998 const char *buf, size_t length)
3999{
Christoph Lameter434e2452007-07-17 04:03:30 -07004000 int ret = -EINVAL;
4001
4002 if (buf[0] == '1') {
4003 ret = validate_slab_cache(s);
4004 if (ret >= 0)
4005 ret = length;
4006 }
4007 return ret;
Christoph Lameter53e15af2007-05-06 14:49:43 -07004008}
4009SLAB_ATTR(validate);
4010
Christoph Lameter2086d262007-05-06 14:49:46 -07004011static ssize_t shrink_show(struct kmem_cache *s, char *buf)
4012{
4013 return 0;
4014}
4015
4016static ssize_t shrink_store(struct kmem_cache *s,
4017 const char *buf, size_t length)
4018{
4019 if (buf[0] == '1') {
4020 int rc = kmem_cache_shrink(s);
4021
4022 if (rc)
4023 return rc;
4024 } else
4025 return -EINVAL;
4026 return length;
4027}
4028SLAB_ATTR(shrink);
4029
Christoph Lameter88a420e2007-05-06 14:49:45 -07004030static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf)
4031{
4032 if (!(s->flags & SLAB_STORE_USER))
4033 return -ENOSYS;
4034 return list_locations(s, buf, TRACK_ALLOC);
4035}
4036SLAB_ATTR_RO(alloc_calls);
4037
4038static ssize_t free_calls_show(struct kmem_cache *s, char *buf)
4039{
4040 if (!(s->flags & SLAB_STORE_USER))
4041 return -ENOSYS;
4042 return list_locations(s, buf, TRACK_FREE);
4043}
4044SLAB_ATTR_RO(free_calls);
4045
Christoph Lameter81819f02007-05-06 14:49:36 -07004046#ifdef CONFIG_NUMA
Christoph Lameter98246012008-01-07 23:20:26 -08004047static ssize_t remote_node_defrag_ratio_show(struct kmem_cache *s, char *buf)
Christoph Lameter81819f02007-05-06 14:49:36 -07004048{
Christoph Lameter98246012008-01-07 23:20:26 -08004049 return sprintf(buf, "%d\n", s->remote_node_defrag_ratio / 10);
Christoph Lameter81819f02007-05-06 14:49:36 -07004050}
4051
Christoph Lameter98246012008-01-07 23:20:26 -08004052static ssize_t remote_node_defrag_ratio_store(struct kmem_cache *s,
Christoph Lameter81819f02007-05-06 14:49:36 -07004053 const char *buf, size_t length)
4054{
Christoph Lameter0121c6192008-04-29 16:11:12 -07004055 unsigned long ratio;
4056 int err;
Christoph Lameter81819f02007-05-06 14:49:36 -07004057
Christoph Lameter0121c6192008-04-29 16:11:12 -07004058 err = strict_strtoul(buf, 10, &ratio);
4059 if (err)
4060 return err;
4061
Christoph Lametere2cb96b2008-08-19 08:51:22 -05004062 if (ratio <= 100)
Christoph Lameter0121c6192008-04-29 16:11:12 -07004063 s->remote_node_defrag_ratio = ratio * 10;
4064
Christoph Lameter81819f02007-05-06 14:49:36 -07004065 return length;
4066}
Christoph Lameter98246012008-01-07 23:20:26 -08004067SLAB_ATTR(remote_node_defrag_ratio);
Christoph Lameter81819f02007-05-06 14:49:36 -07004068#endif
4069
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004070#ifdef CONFIG_SLUB_STATS
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004071static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si)
4072{
4073 unsigned long sum = 0;
4074 int cpu;
4075 int len;
4076 int *data = kmalloc(nr_cpu_ids * sizeof(int), GFP_KERNEL);
4077
4078 if (!data)
4079 return -ENOMEM;
4080
4081 for_each_online_cpu(cpu) {
4082 unsigned x = get_cpu_slab(s, cpu)->stat[si];
4083
4084 data[cpu] = x;
4085 sum += x;
4086 }
4087
4088 len = sprintf(buf, "%lu", sum);
4089
Christoph Lameter50ef37b2008-04-14 18:52:05 +03004090#ifdef CONFIG_SMP
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004091 for_each_online_cpu(cpu) {
4092 if (data[cpu] && len < PAGE_SIZE - 20)
Christoph Lameter50ef37b2008-04-14 18:52:05 +03004093 len += sprintf(buf + len, " C%d=%u", cpu, data[cpu]);
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004094 }
Christoph Lameter50ef37b2008-04-14 18:52:05 +03004095#endif
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004096 kfree(data);
4097 return len + sprintf(buf + len, "\n");
4098}
4099
4100#define STAT_ATTR(si, text) \
4101static ssize_t text##_show(struct kmem_cache *s, char *buf) \
4102{ \
4103 return show_stat(s, buf, si); \
4104} \
4105SLAB_ATTR_RO(text); \
4106
4107STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath);
4108STAT_ATTR(ALLOC_SLOWPATH, alloc_slowpath);
4109STAT_ATTR(FREE_FASTPATH, free_fastpath);
4110STAT_ATTR(FREE_SLOWPATH, free_slowpath);
4111STAT_ATTR(FREE_FROZEN, free_frozen);
4112STAT_ATTR(FREE_ADD_PARTIAL, free_add_partial);
4113STAT_ATTR(FREE_REMOVE_PARTIAL, free_remove_partial);
4114STAT_ATTR(ALLOC_FROM_PARTIAL, alloc_from_partial);
4115STAT_ATTR(ALLOC_SLAB, alloc_slab);
4116STAT_ATTR(ALLOC_REFILL, alloc_refill);
4117STAT_ATTR(FREE_SLAB, free_slab);
4118STAT_ATTR(CPUSLAB_FLUSH, cpuslab_flush);
4119STAT_ATTR(DEACTIVATE_FULL, deactivate_full);
4120STAT_ATTR(DEACTIVATE_EMPTY, deactivate_empty);
4121STAT_ATTR(DEACTIVATE_TO_HEAD, deactivate_to_head);
4122STAT_ATTR(DEACTIVATE_TO_TAIL, deactivate_to_tail);
4123STAT_ATTR(DEACTIVATE_REMOTE_FREES, deactivate_remote_frees);
Christoph Lameter65c33762008-04-14 19:11:40 +03004124STAT_ATTR(ORDER_FALLBACK, order_fallback);
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004125#endif
4126
Pekka Enberg06428782008-01-07 23:20:27 -08004127static struct attribute *slab_attrs[] = {
Christoph Lameter81819f02007-05-06 14:49:36 -07004128 &slab_size_attr.attr,
4129 &object_size_attr.attr,
4130 &objs_per_slab_attr.attr,
4131 &order_attr.attr,
4132 &objects_attr.attr,
Christoph Lameter205ab992008-04-14 19:11:40 +03004133 &objects_partial_attr.attr,
4134 &total_objects_attr.attr,
Christoph Lameter81819f02007-05-06 14:49:36 -07004135 &slabs_attr.attr,
4136 &partial_attr.attr,
4137 &cpu_slabs_attr.attr,
4138 &ctor_attr.attr,
Christoph Lameter81819f02007-05-06 14:49:36 -07004139 &aliases_attr.attr,
4140 &align_attr.attr,
4141 &sanity_checks_attr.attr,
4142 &trace_attr.attr,
4143 &hwcache_align_attr.attr,
4144 &reclaim_account_attr.attr,
4145 &destroy_by_rcu_attr.attr,
4146 &red_zone_attr.attr,
4147 &poison_attr.attr,
4148 &store_user_attr.attr,
Christoph Lameter53e15af2007-05-06 14:49:43 -07004149 &validate_attr.attr,
Christoph Lameter2086d262007-05-06 14:49:46 -07004150 &shrink_attr.attr,
Christoph Lameter88a420e2007-05-06 14:49:45 -07004151 &alloc_calls_attr.attr,
4152 &free_calls_attr.attr,
Christoph Lameter81819f02007-05-06 14:49:36 -07004153#ifdef CONFIG_ZONE_DMA
4154 &cache_dma_attr.attr,
4155#endif
4156#ifdef CONFIG_NUMA
Christoph Lameter98246012008-01-07 23:20:26 -08004157 &remote_node_defrag_ratio_attr.attr,
Christoph Lameter81819f02007-05-06 14:49:36 -07004158#endif
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004159#ifdef CONFIG_SLUB_STATS
4160 &alloc_fastpath_attr.attr,
4161 &alloc_slowpath_attr.attr,
4162 &free_fastpath_attr.attr,
4163 &free_slowpath_attr.attr,
4164 &free_frozen_attr.attr,
4165 &free_add_partial_attr.attr,
4166 &free_remove_partial_attr.attr,
4167 &alloc_from_partial_attr.attr,
4168 &alloc_slab_attr.attr,
4169 &alloc_refill_attr.attr,
4170 &free_slab_attr.attr,
4171 &cpuslab_flush_attr.attr,
4172 &deactivate_full_attr.attr,
4173 &deactivate_empty_attr.attr,
4174 &deactivate_to_head_attr.attr,
4175 &deactivate_to_tail_attr.attr,
4176 &deactivate_remote_frees_attr.attr,
Christoph Lameter65c33762008-04-14 19:11:40 +03004177 &order_fallback_attr.attr,
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004178#endif
Christoph Lameter81819f02007-05-06 14:49:36 -07004179 NULL
4180};
4181
4182static struct attribute_group slab_attr_group = {
4183 .attrs = slab_attrs,
4184};
4185
4186static ssize_t slab_attr_show(struct kobject *kobj,
4187 struct attribute *attr,
4188 char *buf)
4189{
4190 struct slab_attribute *attribute;
4191 struct kmem_cache *s;
4192 int err;
4193
4194 attribute = to_slab_attr(attr);
4195 s = to_slab(kobj);
4196
4197 if (!attribute->show)
4198 return -EIO;
4199
4200 err = attribute->show(s, buf);
4201
4202 return err;
4203}
4204
4205static ssize_t slab_attr_store(struct kobject *kobj,
4206 struct attribute *attr,
4207 const char *buf, size_t len)
4208{
4209 struct slab_attribute *attribute;
4210 struct kmem_cache *s;
4211 int err;
4212
4213 attribute = to_slab_attr(attr);
4214 s = to_slab(kobj);
4215
4216 if (!attribute->store)
4217 return -EIO;
4218
4219 err = attribute->store(s, buf, len);
4220
4221 return err;
4222}
4223
Christoph Lameter151c6022008-01-07 22:29:05 -08004224static void kmem_cache_release(struct kobject *kobj)
4225{
4226 struct kmem_cache *s = to_slab(kobj);
4227
4228 kfree(s);
4229}
4230
Christoph Lameter81819f02007-05-06 14:49:36 -07004231static struct sysfs_ops slab_sysfs_ops = {
4232 .show = slab_attr_show,
4233 .store = slab_attr_store,
4234};
4235
4236static struct kobj_type slab_ktype = {
4237 .sysfs_ops = &slab_sysfs_ops,
Christoph Lameter151c6022008-01-07 22:29:05 -08004238 .release = kmem_cache_release
Christoph Lameter81819f02007-05-06 14:49:36 -07004239};
4240
4241static int uevent_filter(struct kset *kset, struct kobject *kobj)
4242{
4243 struct kobj_type *ktype = get_ktype(kobj);
4244
4245 if (ktype == &slab_ktype)
4246 return 1;
4247 return 0;
4248}
4249
4250static struct kset_uevent_ops slab_uevent_ops = {
4251 .filter = uevent_filter,
4252};
4253
Greg Kroah-Hartman27c3a312007-11-01 09:29:06 -06004254static struct kset *slab_kset;
Christoph Lameter81819f02007-05-06 14:49:36 -07004255
4256#define ID_STR_LENGTH 64
4257
4258/* Create a unique string id for a slab cache:
Christoph Lameter6446faa2008-02-15 23:45:26 -08004259 *
4260 * Format :[flags-]size
Christoph Lameter81819f02007-05-06 14:49:36 -07004261 */
4262static char *create_unique_id(struct kmem_cache *s)
4263{
4264 char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL);
4265 char *p = name;
4266
4267 BUG_ON(!name);
4268
4269 *p++ = ':';
4270 /*
4271 * First flags affecting slabcache operations. We will only
4272 * get here for aliasable slabs so we do not need to support
4273 * too many flags. The flags here must cover all flags that
4274 * are matched during merging to guarantee that the id is
4275 * unique.
4276 */
4277 if (s->flags & SLAB_CACHE_DMA)
4278 *p++ = 'd';
4279 if (s->flags & SLAB_RECLAIM_ACCOUNT)
4280 *p++ = 'a';
4281 if (s->flags & SLAB_DEBUG_FREE)
4282 *p++ = 'F';
4283 if (p != name + 1)
4284 *p++ = '-';
4285 p += sprintf(p, "%07d", s->size);
4286 BUG_ON(p > name + ID_STR_LENGTH - 1);
4287 return name;
4288}
4289
4290static int sysfs_slab_add(struct kmem_cache *s)
4291{
4292 int err;
4293 const char *name;
4294 int unmergeable;
4295
4296 if (slab_state < SYSFS)
4297 /* Defer until later */
4298 return 0;
4299
4300 unmergeable = slab_unmergeable(s);
4301 if (unmergeable) {
4302 /*
4303 * Slabcache can never be merged so we can use the name proper.
4304 * This is typically the case for debug situations. In that
4305 * case we can catch duplicate names easily.
4306 */
Greg Kroah-Hartman27c3a312007-11-01 09:29:06 -06004307 sysfs_remove_link(&slab_kset->kobj, s->name);
Christoph Lameter81819f02007-05-06 14:49:36 -07004308 name = s->name;
4309 } else {
4310 /*
4311 * Create a unique name for the slab as a target
4312 * for the symlinks.
4313 */
4314 name = create_unique_id(s);
4315 }
4316
Greg Kroah-Hartman27c3a312007-11-01 09:29:06 -06004317 s->kobj.kset = slab_kset;
Greg Kroah-Hartman1eada112007-12-17 23:05:35 -07004318 err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, name);
4319 if (err) {
4320 kobject_put(&s->kobj);
Christoph Lameter81819f02007-05-06 14:49:36 -07004321 return err;
Greg Kroah-Hartman1eada112007-12-17 23:05:35 -07004322 }
Christoph Lameter81819f02007-05-06 14:49:36 -07004323
4324 err = sysfs_create_group(&s->kobj, &slab_attr_group);
4325 if (err)
4326 return err;
4327 kobject_uevent(&s->kobj, KOBJ_ADD);
4328 if (!unmergeable) {
4329 /* Setup first alias */
4330 sysfs_slab_alias(s, s->name);
4331 kfree(name);
4332 }
4333 return 0;
4334}
4335
4336static void sysfs_slab_remove(struct kmem_cache *s)
4337{
4338 kobject_uevent(&s->kobj, KOBJ_REMOVE);
4339 kobject_del(&s->kobj);
Christoph Lameter151c6022008-01-07 22:29:05 -08004340 kobject_put(&s->kobj);
Christoph Lameter81819f02007-05-06 14:49:36 -07004341}
4342
4343/*
4344 * Need to buffer aliases during bootup until sysfs becomes
4345 * available lest we loose that information.
4346 */
4347struct saved_alias {
4348 struct kmem_cache *s;
4349 const char *name;
4350 struct saved_alias *next;
4351};
4352
Adrian Bunk5af328a2007-07-17 04:03:27 -07004353static struct saved_alias *alias_list;
Christoph Lameter81819f02007-05-06 14:49:36 -07004354
4355static int sysfs_slab_alias(struct kmem_cache *s, const char *name)
4356{
4357 struct saved_alias *al;
4358
4359 if (slab_state == SYSFS) {
4360 /*
4361 * If we have a leftover link then remove it.
4362 */
Greg Kroah-Hartman27c3a312007-11-01 09:29:06 -06004363 sysfs_remove_link(&slab_kset->kobj, name);
4364 return sysfs_create_link(&slab_kset->kobj, &s->kobj, name);
Christoph Lameter81819f02007-05-06 14:49:36 -07004365 }
4366
4367 al = kmalloc(sizeof(struct saved_alias), GFP_KERNEL);
4368 if (!al)
4369 return -ENOMEM;
4370
4371 al->s = s;
4372 al->name = name;
4373 al->next = alias_list;
4374 alias_list = al;
4375 return 0;
4376}
4377
4378static int __init slab_sysfs_init(void)
4379{
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07004380 struct kmem_cache *s;
Christoph Lameter81819f02007-05-06 14:49:36 -07004381 int err;
4382
Greg Kroah-Hartman0ff21e42007-11-06 10:36:58 -08004383 slab_kset = kset_create_and_add("slab", &slab_uevent_ops, kernel_kobj);
Greg Kroah-Hartman27c3a312007-11-01 09:29:06 -06004384 if (!slab_kset) {
Christoph Lameter81819f02007-05-06 14:49:36 -07004385 printk(KERN_ERR "Cannot register slab subsystem.\n");
4386 return -ENOSYS;
4387 }
4388
Christoph Lameter26a7bd02007-05-09 02:32:39 -07004389 slab_state = SYSFS;
4390
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07004391 list_for_each_entry(s, &slab_caches, list) {
Christoph Lameter26a7bd02007-05-09 02:32:39 -07004392 err = sysfs_slab_add(s);
Christoph Lameter5d540fb2007-08-30 23:56:26 -07004393 if (err)
4394 printk(KERN_ERR "SLUB: Unable to add boot slab %s"
4395 " to sysfs\n", s->name);
Christoph Lameter26a7bd02007-05-09 02:32:39 -07004396 }
Christoph Lameter81819f02007-05-06 14:49:36 -07004397
4398 while (alias_list) {
4399 struct saved_alias *al = alias_list;
4400
4401 alias_list = alias_list->next;
4402 err = sysfs_slab_alias(al->s, al->name);
Christoph Lameter5d540fb2007-08-30 23:56:26 -07004403 if (err)
4404 printk(KERN_ERR "SLUB: Unable to add boot slab alias"
4405 " %s to sysfs\n", s->name);
Christoph Lameter81819f02007-05-06 14:49:36 -07004406 kfree(al);
4407 }
4408
4409 resiliency_test();
4410 return 0;
4411}
4412
4413__initcall(slab_sysfs_init);
Christoph Lameter81819f02007-05-06 14:49:36 -07004414#endif
Pekka J Enberg57ed3ed2008-01-01 17:23:28 +01004415
4416/*
4417 * The /proc/slabinfo ABI
4418 */
Linus Torvalds158a9622008-01-02 13:04:48 -08004419#ifdef CONFIG_SLABINFO
4420
Christoph Lameter0121c6192008-04-29 16:11:12 -07004421ssize_t slabinfo_write(struct file *file, const char __user *buffer,
4422 size_t count, loff_t *ppos)
Linus Torvalds158a9622008-01-02 13:04:48 -08004423{
4424 return -EINVAL;
4425}
4426
Pekka J Enberg57ed3ed2008-01-01 17:23:28 +01004427
4428static void print_slabinfo_header(struct seq_file *m)
4429{
4430 seq_puts(m, "slabinfo - version: 2.1\n");
4431 seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
4432 "<objperslab> <pagesperslab>");
4433 seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
4434 seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
4435 seq_putc(m, '\n');
4436}
4437
4438static void *s_start(struct seq_file *m, loff_t *pos)
4439{
4440 loff_t n = *pos;
4441
4442 down_read(&slub_lock);
4443 if (!n)
4444 print_slabinfo_header(m);
4445
4446 return seq_list_start(&slab_caches, *pos);
4447}
4448
4449static void *s_next(struct seq_file *m, void *p, loff_t *pos)
4450{
4451 return seq_list_next(p, &slab_caches, pos);
4452}
4453
4454static void s_stop(struct seq_file *m, void *p)
4455{
4456 up_read(&slub_lock);
4457}
4458
4459static int s_show(struct seq_file *m, void *p)
4460{
4461 unsigned long nr_partials = 0;
4462 unsigned long nr_slabs = 0;
4463 unsigned long nr_inuse = 0;
Christoph Lameter205ab992008-04-14 19:11:40 +03004464 unsigned long nr_objs = 0;
4465 unsigned long nr_free = 0;
Pekka J Enberg57ed3ed2008-01-01 17:23:28 +01004466 struct kmem_cache *s;
4467 int node;
4468
4469 s = list_entry(p, struct kmem_cache, list);
4470
4471 for_each_online_node(node) {
4472 struct kmem_cache_node *n = get_node(s, node);
4473
4474 if (!n)
4475 continue;
4476
4477 nr_partials += n->nr_partial;
4478 nr_slabs += atomic_long_read(&n->nr_slabs);
Christoph Lameter205ab992008-04-14 19:11:40 +03004479 nr_objs += atomic_long_read(&n->total_objects);
4480 nr_free += count_partial(n, count_free);
Pekka J Enberg57ed3ed2008-01-01 17:23:28 +01004481 }
4482
Christoph Lameter205ab992008-04-14 19:11:40 +03004483 nr_inuse = nr_objs - nr_free;
Pekka J Enberg57ed3ed2008-01-01 17:23:28 +01004484
4485 seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", s->name, nr_inuse,
Christoph Lameter834f3d12008-04-14 19:11:31 +03004486 nr_objs, s->size, oo_objects(s->oo),
4487 (1 << oo_order(s->oo)));
Pekka J Enberg57ed3ed2008-01-01 17:23:28 +01004488 seq_printf(m, " : tunables %4u %4u %4u", 0, 0, 0);
4489 seq_printf(m, " : slabdata %6lu %6lu %6lu", nr_slabs, nr_slabs,
4490 0UL);
4491 seq_putc(m, '\n');
4492 return 0;
4493}
4494
4495const struct seq_operations slabinfo_op = {
4496 .start = s_start,
4497 .next = s_next,
4498 .stop = s_stop,
4499 .show = s_show,
4500};
4501
Linus Torvalds158a9622008-01-02 13:04:48 -08004502#endif /* CONFIG_SLABINFO */