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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);
Christoph Lameter643b1132007-05-06 14:49:42 -07001935 INIT_LIST_HEAD(&n->full);
Christoph Lameter8ab13722007-07-17 04:03:32 -07001936#endif
Christoph Lameter81819f02007-05-06 14:49:36 -07001937}
1938
Christoph Lameter4c93c3552007-10-16 01:26:08 -07001939#ifdef CONFIG_SMP
1940/*
1941 * Per cpu array for per cpu structures.
1942 *
1943 * The per cpu array places all kmem_cache_cpu structures from one processor
1944 * close together meaning that it becomes possible that multiple per cpu
1945 * structures are contained in one cacheline. This may be particularly
1946 * beneficial for the kmalloc caches.
1947 *
1948 * A desktop system typically has around 60-80 slabs. With 100 here we are
1949 * likely able to get per cpu structures for all caches from the array defined
1950 * here. We must be able to cover all kmalloc caches during bootstrap.
1951 *
1952 * If the per cpu array is exhausted then fall back to kmalloc
1953 * of individual cachelines. No sharing is possible then.
1954 */
1955#define NR_KMEM_CACHE_CPU 100
1956
1957static DEFINE_PER_CPU(struct kmem_cache_cpu,
1958 kmem_cache_cpu)[NR_KMEM_CACHE_CPU];
1959
1960static DEFINE_PER_CPU(struct kmem_cache_cpu *, kmem_cache_cpu_free);
1961static cpumask_t kmem_cach_cpu_free_init_once = CPU_MASK_NONE;
1962
1963static struct kmem_cache_cpu *alloc_kmem_cache_cpu(struct kmem_cache *s,
1964 int cpu, gfp_t flags)
1965{
1966 struct kmem_cache_cpu *c = per_cpu(kmem_cache_cpu_free, cpu);
1967
1968 if (c)
1969 per_cpu(kmem_cache_cpu_free, cpu) =
1970 (void *)c->freelist;
1971 else {
1972 /* Table overflow: So allocate ourselves */
1973 c = kmalloc_node(
1974 ALIGN(sizeof(struct kmem_cache_cpu), cache_line_size()),
1975 flags, cpu_to_node(cpu));
1976 if (!c)
1977 return NULL;
1978 }
1979
1980 init_kmem_cache_cpu(s, c);
1981 return c;
1982}
1983
1984static void free_kmem_cache_cpu(struct kmem_cache_cpu *c, int cpu)
1985{
1986 if (c < per_cpu(kmem_cache_cpu, cpu) ||
1987 c > per_cpu(kmem_cache_cpu, cpu) + NR_KMEM_CACHE_CPU) {
1988 kfree(c);
1989 return;
1990 }
1991 c->freelist = (void *)per_cpu(kmem_cache_cpu_free, cpu);
1992 per_cpu(kmem_cache_cpu_free, cpu) = c;
1993}
1994
1995static void free_kmem_cache_cpus(struct kmem_cache *s)
1996{
1997 int cpu;
1998
1999 for_each_online_cpu(cpu) {
2000 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
2001
2002 if (c) {
2003 s->cpu_slab[cpu] = NULL;
2004 free_kmem_cache_cpu(c, cpu);
2005 }
2006 }
2007}
2008
2009static int alloc_kmem_cache_cpus(struct kmem_cache *s, gfp_t flags)
2010{
2011 int cpu;
2012
2013 for_each_online_cpu(cpu) {
2014 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
2015
2016 if (c)
2017 continue;
2018
2019 c = alloc_kmem_cache_cpu(s, cpu, flags);
2020 if (!c) {
2021 free_kmem_cache_cpus(s);
2022 return 0;
2023 }
2024 s->cpu_slab[cpu] = c;
2025 }
2026 return 1;
2027}
2028
2029/*
2030 * Initialize the per cpu array.
2031 */
2032static void init_alloc_cpu_cpu(int cpu)
2033{
2034 int i;
2035
2036 if (cpu_isset(cpu, kmem_cach_cpu_free_init_once))
2037 return;
2038
2039 for (i = NR_KMEM_CACHE_CPU - 1; i >= 0; i--)
2040 free_kmem_cache_cpu(&per_cpu(kmem_cache_cpu, cpu)[i], cpu);
2041
2042 cpu_set(cpu, kmem_cach_cpu_free_init_once);
2043}
2044
2045static void __init init_alloc_cpu(void)
2046{
2047 int cpu;
2048
2049 for_each_online_cpu(cpu)
2050 init_alloc_cpu_cpu(cpu);
2051 }
2052
2053#else
2054static inline void free_kmem_cache_cpus(struct kmem_cache *s) {}
2055static inline void init_alloc_cpu(void) {}
2056
2057static inline int alloc_kmem_cache_cpus(struct kmem_cache *s, gfp_t flags)
2058{
2059 init_kmem_cache_cpu(s, &s->cpu_slab);
2060 return 1;
2061}
2062#endif
2063
Christoph Lameter81819f02007-05-06 14:49:36 -07002064#ifdef CONFIG_NUMA
2065/*
2066 * No kmalloc_node yet so do it by hand. We know that this is the first
2067 * slab on the node for this slabcache. There are no concurrent accesses
2068 * possible.
2069 *
2070 * Note that this function only works on the kmalloc_node_cache
Christoph Lameter4c93c3552007-10-16 01:26:08 -07002071 * when allocating for the kmalloc_node_cache. This is used for bootstrapping
2072 * memory on a fresh node that has no slab structures yet.
Christoph Lameter81819f02007-05-06 14:49:36 -07002073 */
Adrian Bunk1cd7daa2007-10-16 01:24:18 -07002074static struct kmem_cache_node *early_kmem_cache_node_alloc(gfp_t gfpflags,
2075 int node)
Christoph Lameter81819f02007-05-06 14:49:36 -07002076{
2077 struct page *page;
2078 struct kmem_cache_node *n;
rootba84c732008-01-07 23:20:28 -08002079 unsigned long flags;
Christoph Lameter81819f02007-05-06 14:49:36 -07002080
2081 BUG_ON(kmalloc_caches->size < sizeof(struct kmem_cache_node));
2082
Christoph Lametera2f92ee2007-08-22 14:01:57 -07002083 page = new_slab(kmalloc_caches, gfpflags, node);
Christoph Lameter81819f02007-05-06 14:49:36 -07002084
2085 BUG_ON(!page);
Christoph Lametera2f92ee2007-08-22 14:01:57 -07002086 if (page_to_nid(page) != node) {
2087 printk(KERN_ERR "SLUB: Unable to allocate memory from "
2088 "node %d\n", node);
2089 printk(KERN_ERR "SLUB: Allocating a useless per node structure "
2090 "in order to be able to continue\n");
2091 }
2092
Christoph Lameter81819f02007-05-06 14:49:36 -07002093 n = page->freelist;
2094 BUG_ON(!n);
2095 page->freelist = get_freepointer(kmalloc_caches, n);
2096 page->inuse++;
2097 kmalloc_caches->node[node] = n;
Christoph Lameter8ab13722007-07-17 04:03:32 -07002098#ifdef CONFIG_SLUB_DEBUG
Christoph Lameterd45f39c2007-07-17 04:03:21 -07002099 init_object(kmalloc_caches, n, 1);
2100 init_tracking(kmalloc_caches, n);
Christoph Lameter8ab13722007-07-17 04:03:32 -07002101#endif
Pekka Enberg5595cff2008-08-05 09:28:47 +03002102 init_kmem_cache_node(n, kmalloc_caches);
Christoph Lameter205ab992008-04-14 19:11:40 +03002103 inc_slabs_node(kmalloc_caches, node, page->objects);
Christoph Lameter6446faa2008-02-15 23:45:26 -08002104
rootba84c732008-01-07 23:20:28 -08002105 /*
2106 * lockdep requires consistent irq usage for each lock
2107 * so even though there cannot be a race this early in
2108 * the boot sequence, we still disable irqs.
2109 */
2110 local_irq_save(flags);
Christoph Lameter7c2e1322008-01-07 23:20:27 -08002111 add_partial(n, page, 0);
rootba84c732008-01-07 23:20:28 -08002112 local_irq_restore(flags);
Christoph Lameter81819f02007-05-06 14:49:36 -07002113 return n;
2114}
2115
2116static void free_kmem_cache_nodes(struct kmem_cache *s)
2117{
2118 int node;
2119
Christoph Lameterf64dc582007-10-16 01:25:33 -07002120 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002121 struct kmem_cache_node *n = s->node[node];
2122 if (n && n != &s->local_node)
2123 kmem_cache_free(kmalloc_caches, n);
2124 s->node[node] = NULL;
2125 }
2126}
2127
2128static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags)
2129{
2130 int node;
2131 int local_node;
2132
2133 if (slab_state >= UP)
2134 local_node = page_to_nid(virt_to_page(s));
2135 else
2136 local_node = 0;
2137
Christoph Lameterf64dc582007-10-16 01:25:33 -07002138 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002139 struct kmem_cache_node *n;
2140
2141 if (local_node == node)
2142 n = &s->local_node;
2143 else {
2144 if (slab_state == DOWN) {
2145 n = early_kmem_cache_node_alloc(gfpflags,
2146 node);
2147 continue;
2148 }
2149 n = kmem_cache_alloc_node(kmalloc_caches,
2150 gfpflags, node);
2151
2152 if (!n) {
2153 free_kmem_cache_nodes(s);
2154 return 0;
2155 }
2156
2157 }
2158 s->node[node] = n;
Pekka Enberg5595cff2008-08-05 09:28:47 +03002159 init_kmem_cache_node(n, s);
Christoph Lameter81819f02007-05-06 14:49:36 -07002160 }
2161 return 1;
2162}
2163#else
2164static void free_kmem_cache_nodes(struct kmem_cache *s)
2165{
2166}
2167
2168static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags)
2169{
Pekka Enberg5595cff2008-08-05 09:28:47 +03002170 init_kmem_cache_node(&s->local_node, s);
Christoph Lameter81819f02007-05-06 14:49:36 -07002171 return 1;
2172}
2173#endif
2174
2175/*
2176 * calculate_sizes() determines the order and the distribution of data within
2177 * a slab object.
2178 */
Christoph Lameter06b285d2008-04-14 19:11:41 +03002179static int calculate_sizes(struct kmem_cache *s, int forced_order)
Christoph Lameter81819f02007-05-06 14:49:36 -07002180{
2181 unsigned long flags = s->flags;
2182 unsigned long size = s->objsize;
2183 unsigned long align = s->align;
Christoph Lameter834f3d12008-04-14 19:11:31 +03002184 int order;
Christoph Lameter81819f02007-05-06 14:49:36 -07002185
2186 /*
Christoph Lameterd8b42bf2008-02-15 23:45:25 -08002187 * Round up object size to the next word boundary. We can only
2188 * place the free pointer at word boundaries and this determines
2189 * the possible location of the free pointer.
2190 */
2191 size = ALIGN(size, sizeof(void *));
2192
2193#ifdef CONFIG_SLUB_DEBUG
2194 /*
Christoph Lameter81819f02007-05-06 14:49:36 -07002195 * Determine if we can poison the object itself. If the user of
2196 * the slab may touch the object after free or before allocation
2197 * then we should never poison the object itself.
2198 */
2199 if ((flags & SLAB_POISON) && !(flags & SLAB_DESTROY_BY_RCU) &&
Christoph Lameterc59def9f2007-05-16 22:10:50 -07002200 !s->ctor)
Christoph Lameter81819f02007-05-06 14:49:36 -07002201 s->flags |= __OBJECT_POISON;
2202 else
2203 s->flags &= ~__OBJECT_POISON;
2204
Christoph Lameter81819f02007-05-06 14:49:36 -07002205
2206 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07002207 * If we are Redzoning then check if there is some space between the
Christoph Lameter81819f02007-05-06 14:49:36 -07002208 * end of the object and the free pointer. If not then add an
Christoph Lameter672bba32007-05-09 02:32:39 -07002209 * additional word to have some bytes to store Redzone information.
Christoph Lameter81819f02007-05-06 14:49:36 -07002210 */
2211 if ((flags & SLAB_RED_ZONE) && size == s->objsize)
2212 size += sizeof(void *);
Christoph Lameter41ecc552007-05-09 02:32:44 -07002213#endif
Christoph Lameter81819f02007-05-06 14:49:36 -07002214
2215 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07002216 * With that we have determined the number of bytes in actual use
2217 * by the object. This is the potential offset to the free pointer.
Christoph Lameter81819f02007-05-06 14:49:36 -07002218 */
2219 s->inuse = size;
2220
2221 if (((flags & (SLAB_DESTROY_BY_RCU | SLAB_POISON)) ||
Christoph Lameterc59def9f2007-05-16 22:10:50 -07002222 s->ctor)) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002223 /*
2224 * Relocate free pointer after the object if it is not
2225 * permitted to overwrite the first word of the object on
2226 * kmem_cache_free.
2227 *
2228 * This is the case if we do RCU, have a constructor or
2229 * destructor or are poisoning the objects.
2230 */
2231 s->offset = size;
2232 size += sizeof(void *);
2233 }
2234
Christoph Lameterc12b3c62007-05-23 13:57:31 -07002235#ifdef CONFIG_SLUB_DEBUG
Christoph Lameter81819f02007-05-06 14:49:36 -07002236 if (flags & SLAB_STORE_USER)
2237 /*
2238 * Need to store information about allocs and frees after
2239 * the object.
2240 */
2241 size += 2 * sizeof(struct track);
2242
Christoph Lameterbe7b3fb2007-05-09 02:32:36 -07002243 if (flags & SLAB_RED_ZONE)
Christoph Lameter81819f02007-05-06 14:49:36 -07002244 /*
2245 * Add some empty padding so that we can catch
2246 * overwrites from earlier objects rather than let
2247 * tracking information or the free pointer be
2248 * corrupted if an user writes before the start
2249 * of the object.
2250 */
2251 size += sizeof(void *);
Christoph Lameter41ecc552007-05-09 02:32:44 -07002252#endif
Christoph Lameter672bba32007-05-09 02:32:39 -07002253
Christoph Lameter81819f02007-05-06 14:49:36 -07002254 /*
2255 * Determine the alignment based on various parameters that the
Christoph Lameter65c02d42007-05-09 02:32:35 -07002256 * user specified and the dynamic determination of cache line size
2257 * on bootup.
Christoph Lameter81819f02007-05-06 14:49:36 -07002258 */
2259 align = calculate_alignment(flags, align, s->objsize);
2260
2261 /*
2262 * SLUB stores one object immediately after another beginning from
2263 * offset 0. In order to align the objects we have to simply size
2264 * each object to conform to the alignment.
2265 */
2266 size = ALIGN(size, align);
2267 s->size = size;
Christoph Lameter06b285d2008-04-14 19:11:41 +03002268 if (forced_order >= 0)
2269 order = forced_order;
2270 else
2271 order = calculate_order(size);
Christoph Lameter81819f02007-05-06 14:49:36 -07002272
Christoph Lameter834f3d12008-04-14 19:11:31 +03002273 if (order < 0)
Christoph Lameter81819f02007-05-06 14:49:36 -07002274 return 0;
2275
Christoph Lameterb7a49f02008-02-14 14:21:32 -08002276 s->allocflags = 0;
Christoph Lameter834f3d12008-04-14 19:11:31 +03002277 if (order)
Christoph Lameterb7a49f02008-02-14 14:21:32 -08002278 s->allocflags |= __GFP_COMP;
2279
2280 if (s->flags & SLAB_CACHE_DMA)
2281 s->allocflags |= SLUB_DMA;
2282
2283 if (s->flags & SLAB_RECLAIM_ACCOUNT)
2284 s->allocflags |= __GFP_RECLAIMABLE;
2285
Christoph Lameter81819f02007-05-06 14:49:36 -07002286 /*
2287 * Determine the number of objects per slab
2288 */
Christoph Lameter834f3d12008-04-14 19:11:31 +03002289 s->oo = oo_make(order, size);
Christoph Lameter65c33762008-04-14 19:11:40 +03002290 s->min = oo_make(get_order(size), size);
Christoph Lameter205ab992008-04-14 19:11:40 +03002291 if (oo_objects(s->oo) > oo_objects(s->max))
2292 s->max = s->oo;
Christoph Lameter81819f02007-05-06 14:49:36 -07002293
Christoph Lameter834f3d12008-04-14 19:11:31 +03002294 return !!oo_objects(s->oo);
Christoph Lameter81819f02007-05-06 14:49:36 -07002295
2296}
2297
Christoph Lameter81819f02007-05-06 14:49:36 -07002298static int kmem_cache_open(struct kmem_cache *s, gfp_t gfpflags,
2299 const char *name, size_t size,
2300 size_t align, unsigned long flags,
Alexey Dobriyan51cc5062008-07-25 19:45:34 -07002301 void (*ctor)(void *))
Christoph Lameter81819f02007-05-06 14:49:36 -07002302{
2303 memset(s, 0, kmem_size);
2304 s->name = name;
2305 s->ctor = ctor;
Christoph Lameter81819f02007-05-06 14:49:36 -07002306 s->objsize = size;
Christoph Lameter81819f02007-05-06 14:49:36 -07002307 s->align = align;
Christoph Lameterba0268a2007-09-11 15:24:11 -07002308 s->flags = kmem_cache_flags(size, flags, name, ctor);
Christoph Lameter81819f02007-05-06 14:49:36 -07002309
Christoph Lameter06b285d2008-04-14 19:11:41 +03002310 if (!calculate_sizes(s, -1))
Christoph Lameter81819f02007-05-06 14:49:36 -07002311 goto error;
2312
2313 s->refcount = 1;
2314#ifdef CONFIG_NUMA
Christoph Lameter98246012008-01-07 23:20:26 -08002315 s->remote_node_defrag_ratio = 100;
Christoph Lameter81819f02007-05-06 14:49:36 -07002316#endif
Christoph Lameterdfb4f092007-10-16 01:26:05 -07002317 if (!init_kmem_cache_nodes(s, gfpflags & ~SLUB_DMA))
2318 goto error;
Christoph Lameter81819f02007-05-06 14:49:36 -07002319
Christoph Lameterdfb4f092007-10-16 01:26:05 -07002320 if (alloc_kmem_cache_cpus(s, gfpflags & ~SLUB_DMA))
Christoph Lameter81819f02007-05-06 14:49:36 -07002321 return 1;
Christoph Lameter4c93c3552007-10-16 01:26:08 -07002322 free_kmem_cache_nodes(s);
Christoph Lameter81819f02007-05-06 14:49:36 -07002323error:
2324 if (flags & SLAB_PANIC)
2325 panic("Cannot create slab %s size=%lu realsize=%u "
2326 "order=%u offset=%u flags=%lx\n",
Christoph Lameter834f3d12008-04-14 19:11:31 +03002327 s->name, (unsigned long)size, s->size, oo_order(s->oo),
Christoph Lameter81819f02007-05-06 14:49:36 -07002328 s->offset, flags);
2329 return 0;
2330}
Christoph Lameter81819f02007-05-06 14:49:36 -07002331
2332/*
2333 * Check if a given pointer is valid
2334 */
2335int kmem_ptr_validate(struct kmem_cache *s, const void *object)
2336{
Pekka Enberg06428782008-01-07 23:20:27 -08002337 struct page *page;
Christoph Lameter81819f02007-05-06 14:49:36 -07002338
2339 page = get_object_page(object);
2340
2341 if (!page || s != page->slab)
2342 /* No slab or wrong slab */
2343 return 0;
2344
Christoph Lameterabcd08a2007-05-09 02:32:37 -07002345 if (!check_valid_pointer(s, page, object))
Christoph Lameter81819f02007-05-06 14:49:36 -07002346 return 0;
2347
2348 /*
2349 * We could also check if the object is on the slabs freelist.
2350 * But this would be too expensive and it seems that the main
Christoph Lameter6446faa2008-02-15 23:45:26 -08002351 * purpose of kmem_ptr_valid() is to check if the object belongs
Christoph Lameter81819f02007-05-06 14:49:36 -07002352 * to a certain slab.
2353 */
2354 return 1;
2355}
2356EXPORT_SYMBOL(kmem_ptr_validate);
2357
2358/*
2359 * Determine the size of a slab object
2360 */
2361unsigned int kmem_cache_size(struct kmem_cache *s)
2362{
2363 return s->objsize;
2364}
2365EXPORT_SYMBOL(kmem_cache_size);
2366
2367const char *kmem_cache_name(struct kmem_cache *s)
2368{
2369 return s->name;
2370}
2371EXPORT_SYMBOL(kmem_cache_name);
2372
Christoph Lameter33b12c32008-04-25 12:22:43 -07002373static void list_slab_objects(struct kmem_cache *s, struct page *page,
2374 const char *text)
Christoph Lameter81819f02007-05-06 14:49:36 -07002375{
Christoph Lameter33b12c32008-04-25 12:22:43 -07002376#ifdef CONFIG_SLUB_DEBUG
2377 void *addr = page_address(page);
2378 void *p;
2379 DECLARE_BITMAP(map, page->objects);
2380
2381 bitmap_zero(map, page->objects);
2382 slab_err(s, page, "%s", text);
2383 slab_lock(page);
2384 for_each_free_object(p, s, page->freelist)
2385 set_bit(slab_index(p, s, addr), map);
2386
2387 for_each_object(p, s, addr, page->objects) {
2388
2389 if (!test_bit(slab_index(p, s, addr), map)) {
2390 printk(KERN_ERR "INFO: Object 0x%p @offset=%tu\n",
2391 p, p - addr);
2392 print_tracking(s, p);
2393 }
2394 }
2395 slab_unlock(page);
2396#endif
2397}
2398
Christoph Lameter81819f02007-05-06 14:49:36 -07002399/*
Christoph Lameter599870b2008-04-23 12:36:52 -07002400 * Attempt to free all partial slabs on a node.
Christoph Lameter81819f02007-05-06 14:49:36 -07002401 */
Christoph Lameter599870b2008-04-23 12:36:52 -07002402static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n)
Christoph Lameter81819f02007-05-06 14:49:36 -07002403{
Christoph Lameter81819f02007-05-06 14:49:36 -07002404 unsigned long flags;
2405 struct page *page, *h;
2406
2407 spin_lock_irqsave(&n->list_lock, flags);
Christoph Lameter33b12c32008-04-25 12:22:43 -07002408 list_for_each_entry_safe(page, h, &n->partial, lru) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002409 if (!page->inuse) {
2410 list_del(&page->lru);
2411 discard_slab(s, page);
Christoph Lameter599870b2008-04-23 12:36:52 -07002412 n->nr_partial--;
Christoph Lameter33b12c32008-04-25 12:22:43 -07002413 } else {
2414 list_slab_objects(s, page,
2415 "Objects remaining on kmem_cache_close()");
Christoph Lameter599870b2008-04-23 12:36:52 -07002416 }
Christoph Lameter33b12c32008-04-25 12:22:43 -07002417 }
Christoph Lameter81819f02007-05-06 14:49:36 -07002418 spin_unlock_irqrestore(&n->list_lock, flags);
Christoph Lameter81819f02007-05-06 14:49:36 -07002419}
2420
2421/*
Christoph Lameter672bba32007-05-09 02:32:39 -07002422 * Release all resources used by a slab cache.
Christoph Lameter81819f02007-05-06 14:49:36 -07002423 */
Christoph Lameter0c710012007-07-17 04:03:24 -07002424static inline int kmem_cache_close(struct kmem_cache *s)
Christoph Lameter81819f02007-05-06 14:49:36 -07002425{
2426 int node;
2427
2428 flush_all(s);
2429
2430 /* Attempt to free all objects */
Christoph Lameter4c93c3552007-10-16 01:26:08 -07002431 free_kmem_cache_cpus(s);
Christoph Lameterf64dc582007-10-16 01:25:33 -07002432 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002433 struct kmem_cache_node *n = get_node(s, node);
2434
Christoph Lameter599870b2008-04-23 12:36:52 -07002435 free_partial(s, n);
2436 if (n->nr_partial || slabs_node(s, node))
Christoph Lameter81819f02007-05-06 14:49:36 -07002437 return 1;
2438 }
2439 free_kmem_cache_nodes(s);
2440 return 0;
2441}
2442
2443/*
2444 * Close a cache and release the kmem_cache structure
2445 * (must be used for caches created using kmem_cache_create)
2446 */
2447void kmem_cache_destroy(struct kmem_cache *s)
2448{
2449 down_write(&slub_lock);
2450 s->refcount--;
2451 if (!s->refcount) {
2452 list_del(&s->list);
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07002453 up_write(&slub_lock);
Pekka Enbergd629d812008-04-23 22:31:08 +03002454 if (kmem_cache_close(s)) {
2455 printk(KERN_ERR "SLUB %s: %s called for cache that "
2456 "still has objects.\n", s->name, __func__);
2457 dump_stack();
2458 }
Christoph Lameter81819f02007-05-06 14:49:36 -07002459 sysfs_slab_remove(s);
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07002460 } else
2461 up_write(&slub_lock);
Christoph Lameter81819f02007-05-06 14:49:36 -07002462}
2463EXPORT_SYMBOL(kmem_cache_destroy);
2464
2465/********************************************************************
2466 * Kmalloc subsystem
2467 *******************************************************************/
2468
Christoph Lameter331dc552008-02-14 14:28:09 -08002469struct kmem_cache kmalloc_caches[PAGE_SHIFT + 1] __cacheline_aligned;
Christoph Lameter81819f02007-05-06 14:49:36 -07002470EXPORT_SYMBOL(kmalloc_caches);
2471
Christoph Lameter81819f02007-05-06 14:49:36 -07002472static int __init setup_slub_min_order(char *str)
2473{
Pekka Enberg06428782008-01-07 23:20:27 -08002474 get_option(&str, &slub_min_order);
Christoph Lameter81819f02007-05-06 14:49:36 -07002475
2476 return 1;
2477}
2478
2479__setup("slub_min_order=", setup_slub_min_order);
2480
2481static int __init setup_slub_max_order(char *str)
2482{
Pekka Enberg06428782008-01-07 23:20:27 -08002483 get_option(&str, &slub_max_order);
Christoph Lameter81819f02007-05-06 14:49:36 -07002484
2485 return 1;
2486}
2487
2488__setup("slub_max_order=", setup_slub_max_order);
2489
2490static int __init setup_slub_min_objects(char *str)
2491{
Pekka Enberg06428782008-01-07 23:20:27 -08002492 get_option(&str, &slub_min_objects);
Christoph Lameter81819f02007-05-06 14:49:36 -07002493
2494 return 1;
2495}
2496
2497__setup("slub_min_objects=", setup_slub_min_objects);
2498
2499static int __init setup_slub_nomerge(char *str)
2500{
2501 slub_nomerge = 1;
2502 return 1;
2503}
2504
2505__setup("slub_nomerge", setup_slub_nomerge);
2506
Christoph Lameter81819f02007-05-06 14:49:36 -07002507static struct kmem_cache *create_kmalloc_cache(struct kmem_cache *s,
2508 const char *name, int size, gfp_t gfp_flags)
2509{
2510 unsigned int flags = 0;
2511
2512 if (gfp_flags & SLUB_DMA)
2513 flags = SLAB_CACHE_DMA;
2514
2515 down_write(&slub_lock);
2516 if (!kmem_cache_open(s, gfp_flags, name, size, ARCH_KMALLOC_MINALIGN,
Christoph Lameter319d1e22008-04-14 19:11:41 +03002517 flags, NULL))
Christoph Lameter81819f02007-05-06 14:49:36 -07002518 goto panic;
2519
2520 list_add(&s->list, &slab_caches);
2521 up_write(&slub_lock);
2522 if (sysfs_slab_add(s))
2523 goto panic;
2524 return s;
2525
2526panic:
2527 panic("Creation of kmalloc slab %s size=%d failed.\n", name, size);
2528}
2529
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002530#ifdef CONFIG_ZONE_DMA
Christoph Lameter4097d602008-04-14 18:51:18 +03002531static struct kmem_cache *kmalloc_caches_dma[PAGE_SHIFT + 1];
Christoph Lameter1ceef402007-08-07 15:11:48 -07002532
2533static void sysfs_add_func(struct work_struct *w)
2534{
2535 struct kmem_cache *s;
2536
2537 down_write(&slub_lock);
2538 list_for_each_entry(s, &slab_caches, list) {
2539 if (s->flags & __SYSFS_ADD_DEFERRED) {
2540 s->flags &= ~__SYSFS_ADD_DEFERRED;
2541 sysfs_slab_add(s);
2542 }
2543 }
2544 up_write(&slub_lock);
2545}
2546
2547static DECLARE_WORK(sysfs_add_work, sysfs_add_func);
2548
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002549static noinline struct kmem_cache *dma_kmalloc_cache(int index, gfp_t flags)
2550{
2551 struct kmem_cache *s;
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002552 char *text;
2553 size_t realsize;
2554
2555 s = kmalloc_caches_dma[index];
2556 if (s)
2557 return s;
2558
2559 /* Dynamically create dma cache */
Christoph Lameter1ceef402007-08-07 15:11:48 -07002560 if (flags & __GFP_WAIT)
2561 down_write(&slub_lock);
2562 else {
2563 if (!down_write_trylock(&slub_lock))
2564 goto out;
2565 }
2566
2567 if (kmalloc_caches_dma[index])
2568 goto unlock_out;
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002569
Christoph Lameter7b55f622007-07-17 04:03:27 -07002570 realsize = kmalloc_caches[index].objsize;
Ingo Molnar3adbefe2008-02-05 17:57:39 -08002571 text = kasprintf(flags & ~SLUB_DMA, "kmalloc_dma-%d",
2572 (unsigned int)realsize);
Christoph Lameter1ceef402007-08-07 15:11:48 -07002573 s = kmalloc(kmem_size, flags & ~SLUB_DMA);
2574
2575 if (!s || !text || !kmem_cache_open(s, flags, text,
2576 realsize, ARCH_KMALLOC_MINALIGN,
2577 SLAB_CACHE_DMA|__SYSFS_ADD_DEFERRED, NULL)) {
2578 kfree(s);
2579 kfree(text);
2580 goto unlock_out;
Christoph Lameterdfce8642007-07-17 04:03:25 -07002581 }
Christoph Lameter1ceef402007-08-07 15:11:48 -07002582
2583 list_add(&s->list, &slab_caches);
2584 kmalloc_caches_dma[index] = s;
2585
2586 schedule_work(&sysfs_add_work);
2587
2588unlock_out:
Christoph Lameterdfce8642007-07-17 04:03:25 -07002589 up_write(&slub_lock);
Christoph Lameter1ceef402007-08-07 15:11:48 -07002590out:
Christoph Lameterdfce8642007-07-17 04:03:25 -07002591 return kmalloc_caches_dma[index];
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002592}
2593#endif
2594
Christoph Lameterf1b26332007-07-17 04:03:26 -07002595/*
2596 * Conversion table for small slabs sizes / 8 to the index in the
2597 * kmalloc array. This is necessary for slabs < 192 since we have non power
2598 * of two cache sizes there. The size of larger slabs can be determined using
2599 * fls.
2600 */
2601static s8 size_index[24] = {
2602 3, /* 8 */
2603 4, /* 16 */
2604 5, /* 24 */
2605 5, /* 32 */
2606 6, /* 40 */
2607 6, /* 48 */
2608 6, /* 56 */
2609 6, /* 64 */
2610 1, /* 72 */
2611 1, /* 80 */
2612 1, /* 88 */
2613 1, /* 96 */
2614 7, /* 104 */
2615 7, /* 112 */
2616 7, /* 120 */
2617 7, /* 128 */
2618 2, /* 136 */
2619 2, /* 144 */
2620 2, /* 152 */
2621 2, /* 160 */
2622 2, /* 168 */
2623 2, /* 176 */
2624 2, /* 184 */
2625 2 /* 192 */
2626};
2627
Christoph Lameter81819f02007-05-06 14:49:36 -07002628static struct kmem_cache *get_slab(size_t size, gfp_t flags)
2629{
Christoph Lameterf1b26332007-07-17 04:03:26 -07002630 int index;
Christoph Lameter81819f02007-05-06 14:49:36 -07002631
Christoph Lameterf1b26332007-07-17 04:03:26 -07002632 if (size <= 192) {
2633 if (!size)
2634 return ZERO_SIZE_PTR;
Christoph Lameter81819f02007-05-06 14:49:36 -07002635
Christoph Lameterf1b26332007-07-17 04:03:26 -07002636 index = size_index[(size - 1) / 8];
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002637 } else
Christoph Lameterf1b26332007-07-17 04:03:26 -07002638 index = fls(size - 1);
Christoph Lameter81819f02007-05-06 14:49:36 -07002639
2640#ifdef CONFIG_ZONE_DMA
Christoph Lameterf1b26332007-07-17 04:03:26 -07002641 if (unlikely((flags & SLUB_DMA)))
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002642 return dma_kmalloc_cache(index, flags);
Christoph Lameterf1b26332007-07-17 04:03:26 -07002643
Christoph Lameter81819f02007-05-06 14:49:36 -07002644#endif
2645 return &kmalloc_caches[index];
2646}
2647
2648void *__kmalloc(size_t size, gfp_t flags)
2649{
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002650 struct kmem_cache *s;
Christoph Lameter81819f02007-05-06 14:49:36 -07002651
Christoph Lameter331dc552008-02-14 14:28:09 -08002652 if (unlikely(size > PAGE_SIZE))
Pekka Enbergeada35e2008-02-11 22:47:46 +02002653 return kmalloc_large(size, flags);
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002654
2655 s = get_slab(size, flags);
2656
2657 if (unlikely(ZERO_OR_NULL_PTR(s)))
Christoph Lameter6cb8f912007-07-17 04:03:22 -07002658 return s;
2659
Christoph Lameterce15fea2007-07-17 04:03:28 -07002660 return slab_alloc(s, flags, -1, __builtin_return_address(0));
Christoph Lameter81819f02007-05-06 14:49:36 -07002661}
2662EXPORT_SYMBOL(__kmalloc);
2663
Christoph Lameterf619cfe2008-03-01 13:56:40 -08002664static void *kmalloc_large_node(size_t size, gfp_t flags, int node)
2665{
2666 struct page *page = alloc_pages_node(node, flags | __GFP_COMP,
2667 get_order(size));
2668
2669 if (page)
2670 return page_address(page);
2671 else
2672 return NULL;
2673}
2674
Christoph Lameter81819f02007-05-06 14:49:36 -07002675#ifdef CONFIG_NUMA
2676void *__kmalloc_node(size_t size, gfp_t flags, int node)
2677{
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002678 struct kmem_cache *s;
Christoph Lameter81819f02007-05-06 14:49:36 -07002679
Christoph Lameter331dc552008-02-14 14:28:09 -08002680 if (unlikely(size > PAGE_SIZE))
Christoph Lameterf619cfe2008-03-01 13:56:40 -08002681 return kmalloc_large_node(size, flags, node);
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002682
2683 s = get_slab(size, flags);
2684
2685 if (unlikely(ZERO_OR_NULL_PTR(s)))
Christoph Lameter6cb8f912007-07-17 04:03:22 -07002686 return s;
2687
Christoph Lameterce15fea2007-07-17 04:03:28 -07002688 return slab_alloc(s, flags, node, __builtin_return_address(0));
Christoph Lameter81819f02007-05-06 14:49:36 -07002689}
2690EXPORT_SYMBOL(__kmalloc_node);
2691#endif
2692
2693size_t ksize(const void *object)
2694{
Christoph Lameter272c1d22007-06-08 13:46:49 -07002695 struct page *page;
Christoph Lameter81819f02007-05-06 14:49:36 -07002696 struct kmem_cache *s;
2697
Christoph Lameteref8b4522007-10-16 01:24:46 -07002698 if (unlikely(object == ZERO_SIZE_PTR))
Christoph Lameter272c1d22007-06-08 13:46:49 -07002699 return 0;
2700
Vegard Nossum294a80a2007-12-04 23:45:30 -08002701 page = virt_to_head_page(object);
Vegard Nossum294a80a2007-12-04 23:45:30 -08002702
Pekka Enberg76994412008-05-22 19:22:25 +03002703 if (unlikely(!PageSlab(page))) {
2704 WARN_ON(!PageCompound(page));
Vegard Nossum294a80a2007-12-04 23:45:30 -08002705 return PAGE_SIZE << compound_order(page);
Pekka Enberg76994412008-05-22 19:22:25 +03002706 }
Christoph Lameter81819f02007-05-06 14:49:36 -07002707 s = page->slab;
Christoph Lameter81819f02007-05-06 14:49:36 -07002708
Christoph Lameterae20bfd2008-02-15 23:45:25 -08002709#ifdef CONFIG_SLUB_DEBUG
Christoph Lameter81819f02007-05-06 14:49:36 -07002710 /*
2711 * Debugging requires use of the padding between object
2712 * and whatever may come after it.
2713 */
2714 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
2715 return s->objsize;
2716
Christoph Lameterae20bfd2008-02-15 23:45:25 -08002717#endif
Christoph Lameter81819f02007-05-06 14:49:36 -07002718 /*
2719 * If we have the need to store the freelist pointer
2720 * back there or track user information then we can
2721 * only use the space before that information.
2722 */
2723 if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER))
2724 return s->inuse;
Christoph Lameter81819f02007-05-06 14:49:36 -07002725 /*
2726 * Else we can use all the padding etc for the allocation
2727 */
2728 return s->size;
2729}
Christoph Lameter81819f02007-05-06 14:49:36 -07002730
2731void kfree(const void *x)
2732{
Christoph Lameter81819f02007-05-06 14:49:36 -07002733 struct page *page;
Christoph Lameter5bb983b2008-02-07 17:47:41 -08002734 void *object = (void *)x;
Christoph Lameter81819f02007-05-06 14:49:36 -07002735
Satyam Sharma2408c552007-10-16 01:24:44 -07002736 if (unlikely(ZERO_OR_NULL_PTR(x)))
Christoph Lameter81819f02007-05-06 14:49:36 -07002737 return;
2738
Christoph Lameterb49af682007-05-06 14:49:41 -07002739 page = virt_to_head_page(x);
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002740 if (unlikely(!PageSlab(page))) {
Christoph Lameter09375022008-05-28 10:32:22 -07002741 BUG_ON(!PageCompound(page));
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002742 put_page(page);
2743 return;
2744 }
Christoph Lameter5bb983b2008-02-07 17:47:41 -08002745 slab_free(page->slab, page, object, __builtin_return_address(0));
Christoph Lameter81819f02007-05-06 14:49:36 -07002746}
2747EXPORT_SYMBOL(kfree);
2748
Christoph Lameter2086d262007-05-06 14:49:46 -07002749/*
Christoph Lameter672bba32007-05-09 02:32:39 -07002750 * kmem_cache_shrink removes empty slabs from the partial lists and sorts
2751 * the remaining slabs by the number of items in use. The slabs with the
2752 * most items in use come first. New allocations will then fill those up
2753 * and thus they can be removed from the partial lists.
2754 *
2755 * The slabs with the least items are placed last. This results in them
2756 * being allocated from last increasing the chance that the last objects
2757 * are freed in them.
Christoph Lameter2086d262007-05-06 14:49:46 -07002758 */
2759int kmem_cache_shrink(struct kmem_cache *s)
2760{
2761 int node;
2762 int i;
2763 struct kmem_cache_node *n;
2764 struct page *page;
2765 struct page *t;
Christoph Lameter205ab992008-04-14 19:11:40 +03002766 int objects = oo_objects(s->max);
Christoph Lameter2086d262007-05-06 14:49:46 -07002767 struct list_head *slabs_by_inuse =
Christoph Lameter834f3d12008-04-14 19:11:31 +03002768 kmalloc(sizeof(struct list_head) * objects, GFP_KERNEL);
Christoph Lameter2086d262007-05-06 14:49:46 -07002769 unsigned long flags;
2770
2771 if (!slabs_by_inuse)
2772 return -ENOMEM;
2773
2774 flush_all(s);
Christoph Lameterf64dc582007-10-16 01:25:33 -07002775 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter2086d262007-05-06 14:49:46 -07002776 n = get_node(s, node);
2777
2778 if (!n->nr_partial)
2779 continue;
2780
Christoph Lameter834f3d12008-04-14 19:11:31 +03002781 for (i = 0; i < objects; i++)
Christoph Lameter2086d262007-05-06 14:49:46 -07002782 INIT_LIST_HEAD(slabs_by_inuse + i);
2783
2784 spin_lock_irqsave(&n->list_lock, flags);
2785
2786 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07002787 * Build lists indexed by the items in use in each slab.
Christoph Lameter2086d262007-05-06 14:49:46 -07002788 *
Christoph Lameter672bba32007-05-09 02:32:39 -07002789 * Note that concurrent frees may occur while we hold the
2790 * list_lock. page->inuse here is the upper limit.
Christoph Lameter2086d262007-05-06 14:49:46 -07002791 */
2792 list_for_each_entry_safe(page, t, &n->partial, lru) {
2793 if (!page->inuse && slab_trylock(page)) {
2794 /*
2795 * Must hold slab lock here because slab_free
2796 * may have freed the last object and be
2797 * waiting to release the slab.
2798 */
2799 list_del(&page->lru);
2800 n->nr_partial--;
2801 slab_unlock(page);
2802 discard_slab(s, page);
2803 } else {
Christoph Lameterfcda3d82007-07-30 13:06:46 -07002804 list_move(&page->lru,
2805 slabs_by_inuse + page->inuse);
Christoph Lameter2086d262007-05-06 14:49:46 -07002806 }
2807 }
2808
Christoph Lameter2086d262007-05-06 14:49:46 -07002809 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07002810 * Rebuild the partial list with the slabs filled up most
2811 * first and the least used slabs at the end.
Christoph Lameter2086d262007-05-06 14:49:46 -07002812 */
Christoph Lameter834f3d12008-04-14 19:11:31 +03002813 for (i = objects - 1; i >= 0; i--)
Christoph Lameter2086d262007-05-06 14:49:46 -07002814 list_splice(slabs_by_inuse + i, n->partial.prev);
2815
Christoph Lameter2086d262007-05-06 14:49:46 -07002816 spin_unlock_irqrestore(&n->list_lock, flags);
2817 }
2818
2819 kfree(slabs_by_inuse);
2820 return 0;
2821}
2822EXPORT_SYMBOL(kmem_cache_shrink);
2823
Yasunori Gotob9049e22007-10-21 16:41:37 -07002824#if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)
2825static int slab_mem_going_offline_callback(void *arg)
2826{
2827 struct kmem_cache *s;
2828
2829 down_read(&slub_lock);
2830 list_for_each_entry(s, &slab_caches, list)
2831 kmem_cache_shrink(s);
2832 up_read(&slub_lock);
2833
2834 return 0;
2835}
2836
2837static void slab_mem_offline_callback(void *arg)
2838{
2839 struct kmem_cache_node *n;
2840 struct kmem_cache *s;
2841 struct memory_notify *marg = arg;
2842 int offline_node;
2843
2844 offline_node = marg->status_change_nid;
2845
2846 /*
2847 * If the node still has available memory. we need kmem_cache_node
2848 * for it yet.
2849 */
2850 if (offline_node < 0)
2851 return;
2852
2853 down_read(&slub_lock);
2854 list_for_each_entry(s, &slab_caches, list) {
2855 n = get_node(s, offline_node);
2856 if (n) {
2857 /*
2858 * if n->nr_slabs > 0, slabs still exist on the node
2859 * that is going down. We were unable to free them,
2860 * and offline_pages() function shoudn't call this
2861 * callback. So, we must fail.
2862 */
Christoph Lameter0f389ec2008-04-14 18:53:02 +03002863 BUG_ON(slabs_node(s, offline_node));
Yasunori Gotob9049e22007-10-21 16:41:37 -07002864
2865 s->node[offline_node] = NULL;
2866 kmem_cache_free(kmalloc_caches, n);
2867 }
2868 }
2869 up_read(&slub_lock);
2870}
2871
2872static int slab_mem_going_online_callback(void *arg)
2873{
2874 struct kmem_cache_node *n;
2875 struct kmem_cache *s;
2876 struct memory_notify *marg = arg;
2877 int nid = marg->status_change_nid;
2878 int ret = 0;
2879
2880 /*
2881 * If the node's memory is already available, then kmem_cache_node is
2882 * already created. Nothing to do.
2883 */
2884 if (nid < 0)
2885 return 0;
2886
2887 /*
Christoph Lameter0121c6192008-04-29 16:11:12 -07002888 * We are bringing a node online. No memory is available yet. We must
Yasunori Gotob9049e22007-10-21 16:41:37 -07002889 * allocate a kmem_cache_node structure in order to bring the node
2890 * online.
2891 */
2892 down_read(&slub_lock);
2893 list_for_each_entry(s, &slab_caches, list) {
2894 /*
2895 * XXX: kmem_cache_alloc_node will fallback to other nodes
2896 * since memory is not yet available from the node that
2897 * is brought up.
2898 */
2899 n = kmem_cache_alloc(kmalloc_caches, GFP_KERNEL);
2900 if (!n) {
2901 ret = -ENOMEM;
2902 goto out;
2903 }
Pekka Enberg5595cff2008-08-05 09:28:47 +03002904 init_kmem_cache_node(n, s);
Yasunori Gotob9049e22007-10-21 16:41:37 -07002905 s->node[nid] = n;
2906 }
2907out:
2908 up_read(&slub_lock);
2909 return ret;
2910}
2911
2912static int slab_memory_callback(struct notifier_block *self,
2913 unsigned long action, void *arg)
2914{
2915 int ret = 0;
2916
2917 switch (action) {
2918 case MEM_GOING_ONLINE:
2919 ret = slab_mem_going_online_callback(arg);
2920 break;
2921 case MEM_GOING_OFFLINE:
2922 ret = slab_mem_going_offline_callback(arg);
2923 break;
2924 case MEM_OFFLINE:
2925 case MEM_CANCEL_ONLINE:
2926 slab_mem_offline_callback(arg);
2927 break;
2928 case MEM_ONLINE:
2929 case MEM_CANCEL_OFFLINE:
2930 break;
2931 }
2932
2933 ret = notifier_from_errno(ret);
2934 return ret;
2935}
2936
2937#endif /* CONFIG_MEMORY_HOTPLUG */
2938
Christoph Lameter81819f02007-05-06 14:49:36 -07002939/********************************************************************
2940 * Basic setup of slabs
2941 *******************************************************************/
2942
2943void __init kmem_cache_init(void)
2944{
2945 int i;
Christoph Lameter4b356be2007-06-16 10:16:13 -07002946 int caches = 0;
Christoph Lameter81819f02007-05-06 14:49:36 -07002947
Christoph Lameter4c93c3552007-10-16 01:26:08 -07002948 init_alloc_cpu();
2949
Christoph Lameter81819f02007-05-06 14:49:36 -07002950#ifdef CONFIG_NUMA
2951 /*
2952 * Must first have the slab cache available for the allocations of the
Christoph Lameter672bba32007-05-09 02:32:39 -07002953 * struct kmem_cache_node's. There is special bootstrap code in
Christoph Lameter81819f02007-05-06 14:49:36 -07002954 * kmem_cache_open for slab_state == DOWN.
2955 */
2956 create_kmalloc_cache(&kmalloc_caches[0], "kmem_cache_node",
2957 sizeof(struct kmem_cache_node), GFP_KERNEL);
Christoph Lameter8ffa6872007-05-31 00:40:51 -07002958 kmalloc_caches[0].refcount = -1;
Christoph Lameter4b356be2007-06-16 10:16:13 -07002959 caches++;
Yasunori Gotob9049e22007-10-21 16:41:37 -07002960
Nadia Derbey0c40ba42008-04-29 01:00:41 -07002961 hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI);
Christoph Lameter81819f02007-05-06 14:49:36 -07002962#endif
2963
2964 /* Able to allocate the per node structures */
2965 slab_state = PARTIAL;
2966
2967 /* Caches that are not of the two-to-the-power-of size */
Christoph Lameter4b356be2007-06-16 10:16:13 -07002968 if (KMALLOC_MIN_SIZE <= 64) {
2969 create_kmalloc_cache(&kmalloc_caches[1],
Christoph Lameter81819f02007-05-06 14:49:36 -07002970 "kmalloc-96", 96, GFP_KERNEL);
Christoph Lameter4b356be2007-06-16 10:16:13 -07002971 caches++;
Christoph Lameter4b356be2007-06-16 10:16:13 -07002972 create_kmalloc_cache(&kmalloc_caches[2],
Christoph Lameter81819f02007-05-06 14:49:36 -07002973 "kmalloc-192", 192, GFP_KERNEL);
Christoph Lameter4b356be2007-06-16 10:16:13 -07002974 caches++;
2975 }
Christoph Lameter81819f02007-05-06 14:49:36 -07002976
Christoph Lameter331dc552008-02-14 14:28:09 -08002977 for (i = KMALLOC_SHIFT_LOW; i <= PAGE_SHIFT; i++) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002978 create_kmalloc_cache(&kmalloc_caches[i],
2979 "kmalloc", 1 << i, GFP_KERNEL);
Christoph Lameter4b356be2007-06-16 10:16:13 -07002980 caches++;
2981 }
Christoph Lameter81819f02007-05-06 14:49:36 -07002982
Christoph Lameterf1b26332007-07-17 04:03:26 -07002983
2984 /*
2985 * Patch up the size_index table if we have strange large alignment
2986 * requirements for the kmalloc array. This is only the case for
Christoph Lameter6446faa2008-02-15 23:45:26 -08002987 * MIPS it seems. The standard arches will not generate any code here.
Christoph Lameterf1b26332007-07-17 04:03:26 -07002988 *
2989 * Largest permitted alignment is 256 bytes due to the way we
2990 * handle the index determination for the smaller caches.
2991 *
2992 * Make sure that nothing crazy happens if someone starts tinkering
2993 * around with ARCH_KMALLOC_MINALIGN
2994 */
2995 BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
2996 (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
2997
Christoph Lameter12ad6842007-07-17 04:03:28 -07002998 for (i = 8; i < KMALLOC_MIN_SIZE; i += 8)
Christoph Lameterf1b26332007-07-17 04:03:26 -07002999 size_index[(i - 1) / 8] = KMALLOC_SHIFT_LOW;
3000
Christoph Lameter41d54d32008-07-03 09:14:26 -05003001 if (KMALLOC_MIN_SIZE == 128) {
3002 /*
3003 * The 192 byte sized cache is not used if the alignment
3004 * is 128 byte. Redirect kmalloc to use the 256 byte cache
3005 * instead.
3006 */
3007 for (i = 128 + 8; i <= 192; i += 8)
3008 size_index[(i - 1) / 8] = 8;
3009 }
3010
Christoph Lameter81819f02007-05-06 14:49:36 -07003011 slab_state = UP;
3012
3013 /* Provide the correct kmalloc names now that the caches are up */
Christoph Lameter331dc552008-02-14 14:28:09 -08003014 for (i = KMALLOC_SHIFT_LOW; i <= PAGE_SHIFT; i++)
Christoph Lameter81819f02007-05-06 14:49:36 -07003015 kmalloc_caches[i]. name =
3016 kasprintf(GFP_KERNEL, "kmalloc-%d", 1 << i);
3017
3018#ifdef CONFIG_SMP
3019 register_cpu_notifier(&slab_notifier);
Christoph Lameter4c93c3552007-10-16 01:26:08 -07003020 kmem_size = offsetof(struct kmem_cache, cpu_slab) +
3021 nr_cpu_ids * sizeof(struct kmem_cache_cpu *);
3022#else
3023 kmem_size = sizeof(struct kmem_cache);
Christoph Lameter81819f02007-05-06 14:49:36 -07003024#endif
3025
Ingo Molnar3adbefe2008-02-05 17:57:39 -08003026 printk(KERN_INFO
3027 "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d,"
Christoph Lameter4b356be2007-06-16 10:16:13 -07003028 " CPUs=%d, Nodes=%d\n",
3029 caches, cache_line_size(),
Christoph Lameter81819f02007-05-06 14:49:36 -07003030 slub_min_order, slub_max_order, slub_min_objects,
3031 nr_cpu_ids, nr_node_ids);
3032}
3033
3034/*
3035 * Find a mergeable slab cache
3036 */
3037static int slab_unmergeable(struct kmem_cache *s)
3038{
3039 if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE))
3040 return 1;
3041
Christoph Lameterc59def9f2007-05-16 22:10:50 -07003042 if (s->ctor)
Christoph Lameter81819f02007-05-06 14:49:36 -07003043 return 1;
3044
Christoph Lameter8ffa6872007-05-31 00:40:51 -07003045 /*
3046 * We may have set a slab to be unmergeable during bootstrap.
3047 */
3048 if (s->refcount < 0)
3049 return 1;
3050
Christoph Lameter81819f02007-05-06 14:49:36 -07003051 return 0;
3052}
3053
3054static struct kmem_cache *find_mergeable(size_t size,
Christoph Lameterba0268a2007-09-11 15:24:11 -07003055 size_t align, unsigned long flags, const char *name,
Alexey Dobriyan51cc5062008-07-25 19:45:34 -07003056 void (*ctor)(void *))
Christoph Lameter81819f02007-05-06 14:49:36 -07003057{
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07003058 struct kmem_cache *s;
Christoph Lameter81819f02007-05-06 14:49:36 -07003059
3060 if (slub_nomerge || (flags & SLUB_NEVER_MERGE))
3061 return NULL;
3062
Christoph Lameterc59def9f2007-05-16 22:10:50 -07003063 if (ctor)
Christoph Lameter81819f02007-05-06 14:49:36 -07003064 return NULL;
3065
3066 size = ALIGN(size, sizeof(void *));
3067 align = calculate_alignment(flags, align, size);
3068 size = ALIGN(size, align);
Christoph Lameterba0268a2007-09-11 15:24:11 -07003069 flags = kmem_cache_flags(size, flags, name, NULL);
Christoph Lameter81819f02007-05-06 14:49:36 -07003070
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07003071 list_for_each_entry(s, &slab_caches, list) {
Christoph Lameter81819f02007-05-06 14:49:36 -07003072 if (slab_unmergeable(s))
3073 continue;
3074
3075 if (size > s->size)
3076 continue;
3077
Christoph Lameterba0268a2007-09-11 15:24:11 -07003078 if ((flags & SLUB_MERGE_SAME) != (s->flags & SLUB_MERGE_SAME))
Christoph Lameter81819f02007-05-06 14:49:36 -07003079 continue;
3080 /*
3081 * Check if alignment is compatible.
3082 * Courtesy of Adrian Drzewiecki
3083 */
Pekka Enberg06428782008-01-07 23:20:27 -08003084 if ((s->size & ~(align - 1)) != s->size)
Christoph Lameter81819f02007-05-06 14:49:36 -07003085 continue;
3086
3087 if (s->size - size >= sizeof(void *))
3088 continue;
3089
3090 return s;
3091 }
3092 return NULL;
3093}
3094
3095struct kmem_cache *kmem_cache_create(const char *name, size_t size,
Alexey Dobriyan51cc5062008-07-25 19:45:34 -07003096 size_t align, unsigned long flags, void (*ctor)(void *))
Christoph Lameter81819f02007-05-06 14:49:36 -07003097{
3098 struct kmem_cache *s;
3099
3100 down_write(&slub_lock);
Christoph Lameterba0268a2007-09-11 15:24:11 -07003101 s = find_mergeable(size, align, flags, name, ctor);
Christoph Lameter81819f02007-05-06 14:49:36 -07003102 if (s) {
Christoph Lameter42a9fdb2007-10-16 01:26:09 -07003103 int cpu;
3104
Christoph Lameter81819f02007-05-06 14:49:36 -07003105 s->refcount++;
3106 /*
3107 * Adjust the object sizes so that we clear
3108 * the complete object on kzalloc.
3109 */
3110 s->objsize = max(s->objsize, (int)size);
Christoph Lameter42a9fdb2007-10-16 01:26:09 -07003111
3112 /*
3113 * And then we need to update the object size in the
3114 * per cpu structures
3115 */
3116 for_each_online_cpu(cpu)
3117 get_cpu_slab(s, cpu)->objsize = s->objsize;
Christoph Lameter6446faa2008-02-15 23:45:26 -08003118
Christoph Lameter81819f02007-05-06 14:49:36 -07003119 s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *)));
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07003120 up_write(&slub_lock);
Christoph Lameter6446faa2008-02-15 23:45:26 -08003121
Christoph Lameter81819f02007-05-06 14:49:36 -07003122 if (sysfs_slab_alias(s, name))
3123 goto err;
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07003124 return s;
3125 }
Christoph Lameter6446faa2008-02-15 23:45:26 -08003126
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07003127 s = kmalloc(kmem_size, GFP_KERNEL);
3128 if (s) {
3129 if (kmem_cache_open(s, GFP_KERNEL, name,
Christoph Lameterc59def9f2007-05-16 22:10:50 -07003130 size, align, flags, ctor)) {
Christoph Lameter81819f02007-05-06 14:49:36 -07003131 list_add(&s->list, &slab_caches);
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07003132 up_write(&slub_lock);
3133 if (sysfs_slab_add(s))
3134 goto err;
3135 return s;
3136 }
3137 kfree(s);
Christoph Lameter81819f02007-05-06 14:49:36 -07003138 }
3139 up_write(&slub_lock);
Christoph Lameter81819f02007-05-06 14:49:36 -07003140
3141err:
Christoph Lameter81819f02007-05-06 14:49:36 -07003142 if (flags & SLAB_PANIC)
3143 panic("Cannot create slabcache %s\n", name);
3144 else
3145 s = NULL;
3146 return s;
3147}
3148EXPORT_SYMBOL(kmem_cache_create);
3149
Christoph Lameter81819f02007-05-06 14:49:36 -07003150#ifdef CONFIG_SMP
Christoph Lameter27390bc2007-06-01 00:47:09 -07003151/*
Christoph Lameter672bba32007-05-09 02:32:39 -07003152 * Use the cpu notifier to insure that the cpu slabs are flushed when
3153 * necessary.
Christoph Lameter81819f02007-05-06 14:49:36 -07003154 */
3155static int __cpuinit slab_cpuup_callback(struct notifier_block *nfb,
3156 unsigned long action, void *hcpu)
3157{
3158 long cpu = (long)hcpu;
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07003159 struct kmem_cache *s;
3160 unsigned long flags;
Christoph Lameter81819f02007-05-06 14:49:36 -07003161
3162 switch (action) {
Christoph Lameter4c93c3552007-10-16 01:26:08 -07003163 case CPU_UP_PREPARE:
3164 case CPU_UP_PREPARE_FROZEN:
3165 init_alloc_cpu_cpu(cpu);
3166 down_read(&slub_lock);
3167 list_for_each_entry(s, &slab_caches, list)
3168 s->cpu_slab[cpu] = alloc_kmem_cache_cpu(s, cpu,
3169 GFP_KERNEL);
3170 up_read(&slub_lock);
3171 break;
3172
Christoph Lameter81819f02007-05-06 14:49:36 -07003173 case CPU_UP_CANCELED:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07003174 case CPU_UP_CANCELED_FROZEN:
Christoph Lameter81819f02007-05-06 14:49:36 -07003175 case CPU_DEAD:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07003176 case CPU_DEAD_FROZEN:
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07003177 down_read(&slub_lock);
3178 list_for_each_entry(s, &slab_caches, list) {
Christoph Lameter4c93c3552007-10-16 01:26:08 -07003179 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
3180
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07003181 local_irq_save(flags);
3182 __flush_cpu_slab(s, cpu);
3183 local_irq_restore(flags);
Christoph Lameter4c93c3552007-10-16 01:26:08 -07003184 free_kmem_cache_cpu(c, cpu);
3185 s->cpu_slab[cpu] = NULL;
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07003186 }
3187 up_read(&slub_lock);
Christoph Lameter81819f02007-05-06 14:49:36 -07003188 break;
3189 default:
3190 break;
3191 }
3192 return NOTIFY_OK;
3193}
3194
Pekka Enberg06428782008-01-07 23:20:27 -08003195static struct notifier_block __cpuinitdata slab_notifier = {
Ingo Molnar3adbefe2008-02-05 17:57:39 -08003196 .notifier_call = slab_cpuup_callback
Pekka Enberg06428782008-01-07 23:20:27 -08003197};
Christoph Lameter81819f02007-05-06 14:49:36 -07003198
3199#endif
3200
Christoph Lameter81819f02007-05-06 14:49:36 -07003201void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, void *caller)
3202{
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07003203 struct kmem_cache *s;
3204
Christoph Lameter331dc552008-02-14 14:28:09 -08003205 if (unlikely(size > PAGE_SIZE))
Pekka Enbergeada35e2008-02-11 22:47:46 +02003206 return kmalloc_large(size, gfpflags);
3207
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07003208 s = get_slab(size, gfpflags);
Christoph Lameter81819f02007-05-06 14:49:36 -07003209
Satyam Sharma2408c552007-10-16 01:24:44 -07003210 if (unlikely(ZERO_OR_NULL_PTR(s)))
Christoph Lameter6cb8f912007-07-17 04:03:22 -07003211 return s;
Christoph Lameter81819f02007-05-06 14:49:36 -07003212
Christoph Lameterce15fea2007-07-17 04:03:28 -07003213 return slab_alloc(s, gfpflags, -1, caller);
Christoph Lameter81819f02007-05-06 14:49:36 -07003214}
3215
3216void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
3217 int node, void *caller)
3218{
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07003219 struct kmem_cache *s;
3220
Christoph Lameter331dc552008-02-14 14:28:09 -08003221 if (unlikely(size > PAGE_SIZE))
Christoph Lameterf619cfe2008-03-01 13:56:40 -08003222 return kmalloc_large_node(size, gfpflags, node);
Pekka Enbergeada35e2008-02-11 22:47:46 +02003223
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07003224 s = get_slab(size, gfpflags);
Christoph Lameter81819f02007-05-06 14:49:36 -07003225
Satyam Sharma2408c552007-10-16 01:24:44 -07003226 if (unlikely(ZERO_OR_NULL_PTR(s)))
Christoph Lameter6cb8f912007-07-17 04:03:22 -07003227 return s;
Christoph Lameter81819f02007-05-06 14:49:36 -07003228
Christoph Lameterce15fea2007-07-17 04:03:28 -07003229 return slab_alloc(s, gfpflags, node, caller);
Christoph Lameter81819f02007-05-06 14:49:36 -07003230}
3231
Christoph Lameterf6acb632008-04-29 16:16:06 -07003232#ifdef CONFIG_SLUB_DEBUG
Christoph Lameter205ab992008-04-14 19:11:40 +03003233static unsigned long count_partial(struct kmem_cache_node *n,
3234 int (*get_count)(struct page *))
Christoph Lameter5b06c8532008-04-14 18:51:34 +03003235{
3236 unsigned long flags;
3237 unsigned long x = 0;
3238 struct page *page;
3239
3240 spin_lock_irqsave(&n->list_lock, flags);
3241 list_for_each_entry(page, &n->partial, lru)
Christoph Lameter205ab992008-04-14 19:11:40 +03003242 x += get_count(page);
Christoph Lameter5b06c8532008-04-14 18:51:34 +03003243 spin_unlock_irqrestore(&n->list_lock, flags);
3244 return x;
3245}
Christoph Lameter205ab992008-04-14 19:11:40 +03003246
3247static int count_inuse(struct page *page)
3248{
3249 return page->inuse;
3250}
3251
3252static int count_total(struct page *page)
3253{
3254 return page->objects;
3255}
3256
3257static int count_free(struct page *page)
3258{
3259 return page->objects - page->inuse;
3260}
Christoph Lameter5b06c8532008-04-14 18:51:34 +03003261
Christoph Lameter434e2452007-07-17 04:03:30 -07003262static int validate_slab(struct kmem_cache *s, struct page *page,
3263 unsigned long *map)
Christoph Lameter53e15af2007-05-06 14:49:43 -07003264{
3265 void *p;
Christoph Lametera973e9d2008-03-01 13:40:44 -08003266 void *addr = page_address(page);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003267
3268 if (!check_slab(s, page) ||
3269 !on_freelist(s, page, NULL))
3270 return 0;
3271
3272 /* Now we know that a valid freelist exists */
Christoph Lameter39b26462008-04-14 19:11:30 +03003273 bitmap_zero(map, page->objects);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003274
Christoph Lameter7656c722007-05-09 02:32:40 -07003275 for_each_free_object(p, s, page->freelist) {
3276 set_bit(slab_index(p, s, addr), map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003277 if (!check_object(s, page, p, 0))
3278 return 0;
3279 }
3280
Christoph Lameter224a88b2008-04-14 19:11:31 +03003281 for_each_object(p, s, addr, page->objects)
Christoph Lameter7656c722007-05-09 02:32:40 -07003282 if (!test_bit(slab_index(p, s, addr), map))
Christoph Lameter53e15af2007-05-06 14:49:43 -07003283 if (!check_object(s, page, p, 1))
3284 return 0;
3285 return 1;
3286}
3287
Christoph Lameter434e2452007-07-17 04:03:30 -07003288static void validate_slab_slab(struct kmem_cache *s, struct page *page,
3289 unsigned long *map)
Christoph Lameter53e15af2007-05-06 14:49:43 -07003290{
3291 if (slab_trylock(page)) {
Christoph Lameter434e2452007-07-17 04:03:30 -07003292 validate_slab(s, page, map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003293 slab_unlock(page);
3294 } else
3295 printk(KERN_INFO "SLUB %s: Skipped busy slab 0x%p\n",
3296 s->name, page);
3297
3298 if (s->flags & DEBUG_DEFAULT_FLAGS) {
Andy Whitcroft8a380822008-07-23 21:27:18 -07003299 if (!PageSlubDebug(page))
3300 printk(KERN_ERR "SLUB %s: SlubDebug not set "
Christoph Lameter53e15af2007-05-06 14:49:43 -07003301 "on slab 0x%p\n", s->name, page);
3302 } else {
Andy Whitcroft8a380822008-07-23 21:27:18 -07003303 if (PageSlubDebug(page))
3304 printk(KERN_ERR "SLUB %s: SlubDebug set on "
Christoph Lameter53e15af2007-05-06 14:49:43 -07003305 "slab 0x%p\n", s->name, page);
3306 }
3307}
3308
Christoph Lameter434e2452007-07-17 04:03:30 -07003309static int validate_slab_node(struct kmem_cache *s,
3310 struct kmem_cache_node *n, unsigned long *map)
Christoph Lameter53e15af2007-05-06 14:49:43 -07003311{
3312 unsigned long count = 0;
3313 struct page *page;
3314 unsigned long flags;
3315
3316 spin_lock_irqsave(&n->list_lock, flags);
3317
3318 list_for_each_entry(page, &n->partial, lru) {
Christoph Lameter434e2452007-07-17 04:03:30 -07003319 validate_slab_slab(s, page, map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003320 count++;
3321 }
3322 if (count != n->nr_partial)
3323 printk(KERN_ERR "SLUB %s: %ld partial slabs counted but "
3324 "counter=%ld\n", s->name, count, n->nr_partial);
3325
3326 if (!(s->flags & SLAB_STORE_USER))
3327 goto out;
3328
3329 list_for_each_entry(page, &n->full, lru) {
Christoph Lameter434e2452007-07-17 04:03:30 -07003330 validate_slab_slab(s, page, map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003331 count++;
3332 }
3333 if (count != atomic_long_read(&n->nr_slabs))
3334 printk(KERN_ERR "SLUB: %s %ld slabs counted but "
3335 "counter=%ld\n", s->name, count,
3336 atomic_long_read(&n->nr_slabs));
3337
3338out:
3339 spin_unlock_irqrestore(&n->list_lock, flags);
3340 return count;
3341}
3342
Christoph Lameter434e2452007-07-17 04:03:30 -07003343static long validate_slab_cache(struct kmem_cache *s)
Christoph Lameter53e15af2007-05-06 14:49:43 -07003344{
3345 int node;
3346 unsigned long count = 0;
Christoph Lameter205ab992008-04-14 19:11:40 +03003347 unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) *
Christoph Lameter434e2452007-07-17 04:03:30 -07003348 sizeof(unsigned long), GFP_KERNEL);
3349
3350 if (!map)
3351 return -ENOMEM;
Christoph Lameter53e15af2007-05-06 14:49:43 -07003352
3353 flush_all(s);
Christoph Lameterf64dc582007-10-16 01:25:33 -07003354 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter53e15af2007-05-06 14:49:43 -07003355 struct kmem_cache_node *n = get_node(s, node);
3356
Christoph Lameter434e2452007-07-17 04:03:30 -07003357 count += validate_slab_node(s, n, map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003358 }
Christoph Lameter434e2452007-07-17 04:03:30 -07003359 kfree(map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003360 return count;
3361}
3362
Christoph Lameterb3459702007-05-09 02:32:41 -07003363#ifdef SLUB_RESILIENCY_TEST
3364static void resiliency_test(void)
3365{
3366 u8 *p;
3367
3368 printk(KERN_ERR "SLUB resiliency testing\n");
3369 printk(KERN_ERR "-----------------------\n");
3370 printk(KERN_ERR "A. Corruption after allocation\n");
3371
3372 p = kzalloc(16, GFP_KERNEL);
3373 p[16] = 0x12;
3374 printk(KERN_ERR "\n1. kmalloc-16: Clobber Redzone/next pointer"
3375 " 0x12->0x%p\n\n", p + 16);
3376
3377 validate_slab_cache(kmalloc_caches + 4);
3378
3379 /* Hmmm... The next two are dangerous */
3380 p = kzalloc(32, GFP_KERNEL);
3381 p[32 + sizeof(void *)] = 0x34;
3382 printk(KERN_ERR "\n2. kmalloc-32: Clobber next pointer/next slab"
Ingo Molnar3adbefe2008-02-05 17:57:39 -08003383 " 0x34 -> -0x%p\n", p);
3384 printk(KERN_ERR
3385 "If allocated object is overwritten then not detectable\n\n");
Christoph Lameterb3459702007-05-09 02:32:41 -07003386
3387 validate_slab_cache(kmalloc_caches + 5);
3388 p = kzalloc(64, GFP_KERNEL);
3389 p += 64 + (get_cycles() & 0xff) * sizeof(void *);
3390 *p = 0x56;
3391 printk(KERN_ERR "\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n",
3392 p);
Ingo Molnar3adbefe2008-02-05 17:57:39 -08003393 printk(KERN_ERR
3394 "If allocated object is overwritten then not detectable\n\n");
Christoph Lameterb3459702007-05-09 02:32:41 -07003395 validate_slab_cache(kmalloc_caches + 6);
3396
3397 printk(KERN_ERR "\nB. Corruption after free\n");
3398 p = kzalloc(128, GFP_KERNEL);
3399 kfree(p);
3400 *p = 0x78;
3401 printk(KERN_ERR "1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p);
3402 validate_slab_cache(kmalloc_caches + 7);
3403
3404 p = kzalloc(256, GFP_KERNEL);
3405 kfree(p);
3406 p[50] = 0x9a;
Ingo Molnar3adbefe2008-02-05 17:57:39 -08003407 printk(KERN_ERR "\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n",
3408 p);
Christoph Lameterb3459702007-05-09 02:32:41 -07003409 validate_slab_cache(kmalloc_caches + 8);
3410
3411 p = kzalloc(512, GFP_KERNEL);
3412 kfree(p);
3413 p[512] = 0xab;
3414 printk(KERN_ERR "\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p);
3415 validate_slab_cache(kmalloc_caches + 9);
3416}
3417#else
3418static void resiliency_test(void) {};
3419#endif
3420
Christoph Lameter88a420e2007-05-06 14:49:45 -07003421/*
Christoph Lameter672bba32007-05-09 02:32:39 -07003422 * Generate lists of code addresses where slabcache objects are allocated
Christoph Lameter88a420e2007-05-06 14:49:45 -07003423 * and freed.
3424 */
3425
3426struct location {
3427 unsigned long count;
3428 void *addr;
Christoph Lameter45edfa52007-05-09 02:32:45 -07003429 long long sum_time;
3430 long min_time;
3431 long max_time;
3432 long min_pid;
3433 long max_pid;
3434 cpumask_t cpus;
3435 nodemask_t nodes;
Christoph Lameter88a420e2007-05-06 14:49:45 -07003436};
3437
3438struct loc_track {
3439 unsigned long max;
3440 unsigned long count;
3441 struct location *loc;
3442};
3443
3444static void free_loc_track(struct loc_track *t)
3445{
3446 if (t->max)
3447 free_pages((unsigned long)t->loc,
3448 get_order(sizeof(struct location) * t->max));
3449}
3450
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003451static int alloc_loc_track(struct loc_track *t, unsigned long max, gfp_t flags)
Christoph Lameter88a420e2007-05-06 14:49:45 -07003452{
3453 struct location *l;
3454 int order;
3455
Christoph Lameter88a420e2007-05-06 14:49:45 -07003456 order = get_order(sizeof(struct location) * max);
3457
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003458 l = (void *)__get_free_pages(flags, order);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003459 if (!l)
3460 return 0;
3461
3462 if (t->count) {
3463 memcpy(l, t->loc, sizeof(struct location) * t->count);
3464 free_loc_track(t);
3465 }
3466 t->max = max;
3467 t->loc = l;
3468 return 1;
3469}
3470
3471static int add_location(struct loc_track *t, struct kmem_cache *s,
Christoph Lameter45edfa52007-05-09 02:32:45 -07003472 const struct track *track)
Christoph Lameter88a420e2007-05-06 14:49:45 -07003473{
3474 long start, end, pos;
3475 struct location *l;
3476 void *caddr;
Christoph Lameter45edfa52007-05-09 02:32:45 -07003477 unsigned long age = jiffies - track->when;
Christoph Lameter88a420e2007-05-06 14:49:45 -07003478
3479 start = -1;
3480 end = t->count;
3481
3482 for ( ; ; ) {
3483 pos = start + (end - start + 1) / 2;
3484
3485 /*
3486 * There is nothing at "end". If we end up there
3487 * we need to add something to before end.
3488 */
3489 if (pos == end)
3490 break;
3491
3492 caddr = t->loc[pos].addr;
Christoph Lameter45edfa52007-05-09 02:32:45 -07003493 if (track->addr == caddr) {
3494
3495 l = &t->loc[pos];
3496 l->count++;
3497 if (track->when) {
3498 l->sum_time += age;
3499 if (age < l->min_time)
3500 l->min_time = age;
3501 if (age > l->max_time)
3502 l->max_time = age;
3503
3504 if (track->pid < l->min_pid)
3505 l->min_pid = track->pid;
3506 if (track->pid > l->max_pid)
3507 l->max_pid = track->pid;
3508
3509 cpu_set(track->cpu, l->cpus);
3510 }
3511 node_set(page_to_nid(virt_to_page(track)), l->nodes);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003512 return 1;
3513 }
3514
Christoph Lameter45edfa52007-05-09 02:32:45 -07003515 if (track->addr < caddr)
Christoph Lameter88a420e2007-05-06 14:49:45 -07003516 end = pos;
3517 else
3518 start = pos;
3519 }
3520
3521 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07003522 * Not found. Insert new tracking element.
Christoph Lameter88a420e2007-05-06 14:49:45 -07003523 */
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003524 if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max, GFP_ATOMIC))
Christoph Lameter88a420e2007-05-06 14:49:45 -07003525 return 0;
3526
3527 l = t->loc + pos;
3528 if (pos < t->count)
3529 memmove(l + 1, l,
3530 (t->count - pos) * sizeof(struct location));
3531 t->count++;
3532 l->count = 1;
Christoph Lameter45edfa52007-05-09 02:32:45 -07003533 l->addr = track->addr;
3534 l->sum_time = age;
3535 l->min_time = age;
3536 l->max_time = age;
3537 l->min_pid = track->pid;
3538 l->max_pid = track->pid;
3539 cpus_clear(l->cpus);
3540 cpu_set(track->cpu, l->cpus);
3541 nodes_clear(l->nodes);
3542 node_set(page_to_nid(virt_to_page(track)), l->nodes);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003543 return 1;
3544}
3545
3546static void process_slab(struct loc_track *t, struct kmem_cache *s,
3547 struct page *page, enum track_item alloc)
3548{
Christoph Lametera973e9d2008-03-01 13:40:44 -08003549 void *addr = page_address(page);
Christoph Lameter39b26462008-04-14 19:11:30 +03003550 DECLARE_BITMAP(map, page->objects);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003551 void *p;
3552
Christoph Lameter39b26462008-04-14 19:11:30 +03003553 bitmap_zero(map, page->objects);
Christoph Lameter7656c722007-05-09 02:32:40 -07003554 for_each_free_object(p, s, page->freelist)
3555 set_bit(slab_index(p, s, addr), map);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003556
Christoph Lameter224a88b2008-04-14 19:11:31 +03003557 for_each_object(p, s, addr, page->objects)
Christoph Lameter45edfa52007-05-09 02:32:45 -07003558 if (!test_bit(slab_index(p, s, addr), map))
3559 add_location(t, s, get_track(s, p, alloc));
Christoph Lameter88a420e2007-05-06 14:49:45 -07003560}
3561
3562static int list_locations(struct kmem_cache *s, char *buf,
3563 enum track_item alloc)
3564{
Harvey Harrisone374d482008-01-31 15:20:50 -08003565 int len = 0;
Christoph Lameter88a420e2007-05-06 14:49:45 -07003566 unsigned long i;
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003567 struct loc_track t = { 0, 0, NULL };
Christoph Lameter88a420e2007-05-06 14:49:45 -07003568 int node;
3569
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003570 if (!alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location),
Andrew Mortonea3061d2007-10-16 01:26:09 -07003571 GFP_TEMPORARY))
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003572 return sprintf(buf, "Out of memory\n");
Christoph Lameter88a420e2007-05-06 14:49:45 -07003573
3574 /* Push back cpu slabs */
3575 flush_all(s);
3576
Christoph Lameterf64dc582007-10-16 01:25:33 -07003577 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter88a420e2007-05-06 14:49:45 -07003578 struct kmem_cache_node *n = get_node(s, node);
3579 unsigned long flags;
3580 struct page *page;
3581
Christoph Lameter9e869432007-08-22 14:01:56 -07003582 if (!atomic_long_read(&n->nr_slabs))
Christoph Lameter88a420e2007-05-06 14:49:45 -07003583 continue;
3584
3585 spin_lock_irqsave(&n->list_lock, flags);
3586 list_for_each_entry(page, &n->partial, lru)
3587 process_slab(&t, s, page, alloc);
3588 list_for_each_entry(page, &n->full, lru)
3589 process_slab(&t, s, page, alloc);
3590 spin_unlock_irqrestore(&n->list_lock, flags);
3591 }
3592
3593 for (i = 0; i < t.count; i++) {
Christoph Lameter45edfa52007-05-09 02:32:45 -07003594 struct location *l = &t.loc[i];
Christoph Lameter88a420e2007-05-06 14:49:45 -07003595
Harvey Harrisone374d482008-01-31 15:20:50 -08003596 if (len > PAGE_SIZE - 100)
Christoph Lameter88a420e2007-05-06 14:49:45 -07003597 break;
Harvey Harrisone374d482008-01-31 15:20:50 -08003598 len += sprintf(buf + len, "%7ld ", l->count);
Christoph Lameter45edfa52007-05-09 02:32:45 -07003599
3600 if (l->addr)
Harvey Harrisone374d482008-01-31 15:20:50 -08003601 len += sprint_symbol(buf + len, (unsigned long)l->addr);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003602 else
Harvey Harrisone374d482008-01-31 15:20:50 -08003603 len += sprintf(buf + len, "<not-available>");
Christoph Lameter45edfa52007-05-09 02:32:45 -07003604
3605 if (l->sum_time != l->min_time) {
Harvey Harrisone374d482008-01-31 15:20:50 -08003606 len += sprintf(buf + len, " age=%ld/%ld/%ld",
Roman Zippelf8bd2252008-05-01 04:34:31 -07003607 l->min_time,
3608 (long)div_u64(l->sum_time, l->count),
3609 l->max_time);
Christoph Lameter45edfa52007-05-09 02:32:45 -07003610 } else
Harvey Harrisone374d482008-01-31 15:20:50 -08003611 len += sprintf(buf + len, " age=%ld",
Christoph Lameter45edfa52007-05-09 02:32:45 -07003612 l->min_time);
3613
3614 if (l->min_pid != l->max_pid)
Harvey Harrisone374d482008-01-31 15:20:50 -08003615 len += sprintf(buf + len, " pid=%ld-%ld",
Christoph Lameter45edfa52007-05-09 02:32:45 -07003616 l->min_pid, l->max_pid);
3617 else
Harvey Harrisone374d482008-01-31 15:20:50 -08003618 len += sprintf(buf + len, " pid=%ld",
Christoph Lameter45edfa52007-05-09 02:32:45 -07003619 l->min_pid);
3620
Christoph Lameter84966342007-06-23 17:16:32 -07003621 if (num_online_cpus() > 1 && !cpus_empty(l->cpus) &&
Harvey Harrisone374d482008-01-31 15:20:50 -08003622 len < PAGE_SIZE - 60) {
3623 len += sprintf(buf + len, " cpus=");
3624 len += cpulist_scnprintf(buf + len, PAGE_SIZE - len - 50,
Christoph Lameter45edfa52007-05-09 02:32:45 -07003625 l->cpus);
3626 }
3627
Christoph Lameter84966342007-06-23 17:16:32 -07003628 if (num_online_nodes() > 1 && !nodes_empty(l->nodes) &&
Harvey Harrisone374d482008-01-31 15:20:50 -08003629 len < PAGE_SIZE - 60) {
3630 len += sprintf(buf + len, " nodes=");
3631 len += nodelist_scnprintf(buf + len, PAGE_SIZE - len - 50,
Christoph Lameter45edfa52007-05-09 02:32:45 -07003632 l->nodes);
3633 }
3634
Harvey Harrisone374d482008-01-31 15:20:50 -08003635 len += sprintf(buf + len, "\n");
Christoph Lameter88a420e2007-05-06 14:49:45 -07003636 }
3637
3638 free_loc_track(&t);
3639 if (!t.count)
Harvey Harrisone374d482008-01-31 15:20:50 -08003640 len += sprintf(buf, "No data\n");
3641 return len;
Christoph Lameter88a420e2007-05-06 14:49:45 -07003642}
3643
Christoph Lameter81819f02007-05-06 14:49:36 -07003644enum slab_stat_type {
Christoph Lameter205ab992008-04-14 19:11:40 +03003645 SL_ALL, /* All slabs */
3646 SL_PARTIAL, /* Only partially allocated slabs */
3647 SL_CPU, /* Only slabs used for cpu caches */
3648 SL_OBJECTS, /* Determine allocated objects not slabs */
3649 SL_TOTAL /* Determine object capacity not slabs */
Christoph Lameter81819f02007-05-06 14:49:36 -07003650};
3651
Christoph Lameter205ab992008-04-14 19:11:40 +03003652#define SO_ALL (1 << SL_ALL)
Christoph Lameter81819f02007-05-06 14:49:36 -07003653#define SO_PARTIAL (1 << SL_PARTIAL)
3654#define SO_CPU (1 << SL_CPU)
3655#define SO_OBJECTS (1 << SL_OBJECTS)
Christoph Lameter205ab992008-04-14 19:11:40 +03003656#define SO_TOTAL (1 << SL_TOTAL)
Christoph Lameter81819f02007-05-06 14:49:36 -07003657
Cyrill Gorcunov62e5c4b2008-03-02 23:28:24 +03003658static ssize_t show_slab_objects(struct kmem_cache *s,
3659 char *buf, unsigned long flags)
Christoph Lameter81819f02007-05-06 14:49:36 -07003660{
3661 unsigned long total = 0;
Christoph Lameter81819f02007-05-06 14:49:36 -07003662 int node;
3663 int x;
3664 unsigned long *nodes;
3665 unsigned long *per_cpu;
3666
3667 nodes = kzalloc(2 * sizeof(unsigned long) * nr_node_ids, GFP_KERNEL);
Cyrill Gorcunov62e5c4b2008-03-02 23:28:24 +03003668 if (!nodes)
3669 return -ENOMEM;
Christoph Lameter81819f02007-05-06 14:49:36 -07003670 per_cpu = nodes + nr_node_ids;
3671
Christoph Lameter205ab992008-04-14 19:11:40 +03003672 if (flags & SO_CPU) {
3673 int cpu;
Christoph Lameter81819f02007-05-06 14:49:36 -07003674
Christoph Lameter205ab992008-04-14 19:11:40 +03003675 for_each_possible_cpu(cpu) {
3676 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
Christoph Lameterdfb4f092007-10-16 01:26:05 -07003677
Christoph Lameter205ab992008-04-14 19:11:40 +03003678 if (!c || c->node < 0)
3679 continue;
3680
3681 if (c->page) {
3682 if (flags & SO_TOTAL)
3683 x = c->page->objects;
3684 else if (flags & SO_OBJECTS)
3685 x = c->page->inuse;
Christoph Lameter81819f02007-05-06 14:49:36 -07003686 else
3687 x = 1;
Christoph Lameter205ab992008-04-14 19:11:40 +03003688
Christoph Lameter81819f02007-05-06 14:49:36 -07003689 total += x;
Christoph Lameter205ab992008-04-14 19:11:40 +03003690 nodes[c->node] += x;
Christoph Lameter81819f02007-05-06 14:49:36 -07003691 }
Christoph Lameter205ab992008-04-14 19:11:40 +03003692 per_cpu[c->node]++;
Christoph Lameter81819f02007-05-06 14:49:36 -07003693 }
3694 }
3695
Christoph Lameter205ab992008-04-14 19:11:40 +03003696 if (flags & SO_ALL) {
3697 for_each_node_state(node, N_NORMAL_MEMORY) {
3698 struct kmem_cache_node *n = get_node(s, node);
Christoph Lameter81819f02007-05-06 14:49:36 -07003699
Christoph Lameter205ab992008-04-14 19:11:40 +03003700 if (flags & SO_TOTAL)
3701 x = atomic_long_read(&n->total_objects);
3702 else if (flags & SO_OBJECTS)
3703 x = atomic_long_read(&n->total_objects) -
3704 count_partial(n, count_free);
3705
3706 else
3707 x = atomic_long_read(&n->nr_slabs);
3708 total += x;
3709 nodes[node] += x;
3710 }
3711
3712 } else if (flags & SO_PARTIAL) {
3713 for_each_node_state(node, N_NORMAL_MEMORY) {
3714 struct kmem_cache_node *n = get_node(s, node);
3715
3716 if (flags & SO_TOTAL)
3717 x = count_partial(n, count_total);
3718 else if (flags & SO_OBJECTS)
3719 x = count_partial(n, count_inuse);
Christoph Lameter81819f02007-05-06 14:49:36 -07003720 else
3721 x = n->nr_partial;
3722 total += x;
3723 nodes[node] += x;
3724 }
Christoph Lameter81819f02007-05-06 14:49:36 -07003725 }
Christoph Lameter81819f02007-05-06 14:49:36 -07003726 x = sprintf(buf, "%lu", total);
3727#ifdef CONFIG_NUMA
Christoph Lameterf64dc582007-10-16 01:25:33 -07003728 for_each_node_state(node, N_NORMAL_MEMORY)
Christoph Lameter81819f02007-05-06 14:49:36 -07003729 if (nodes[node])
3730 x += sprintf(buf + x, " N%d=%lu",
3731 node, nodes[node]);
3732#endif
3733 kfree(nodes);
3734 return x + sprintf(buf + x, "\n");
3735}
3736
3737static int any_slab_objects(struct kmem_cache *s)
3738{
3739 int node;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07003740
3741 for_each_online_node(node) {
Christoph Lameter81819f02007-05-06 14:49:36 -07003742 struct kmem_cache_node *n = get_node(s, node);
3743
Christoph Lameterdfb4f092007-10-16 01:26:05 -07003744 if (!n)
3745 continue;
3746
Benjamin Herrenschmidt4ea33e22008-05-06 20:42:39 -07003747 if (atomic_long_read(&n->total_objects))
Christoph Lameter81819f02007-05-06 14:49:36 -07003748 return 1;
3749 }
3750 return 0;
3751}
3752
3753#define to_slab_attr(n) container_of(n, struct slab_attribute, attr)
3754#define to_slab(n) container_of(n, struct kmem_cache, kobj);
3755
3756struct slab_attribute {
3757 struct attribute attr;
3758 ssize_t (*show)(struct kmem_cache *s, char *buf);
3759 ssize_t (*store)(struct kmem_cache *s, const char *x, size_t count);
3760};
3761
3762#define SLAB_ATTR_RO(_name) \
3763 static struct slab_attribute _name##_attr = __ATTR_RO(_name)
3764
3765#define SLAB_ATTR(_name) \
3766 static struct slab_attribute _name##_attr = \
3767 __ATTR(_name, 0644, _name##_show, _name##_store)
3768
Christoph Lameter81819f02007-05-06 14:49:36 -07003769static ssize_t slab_size_show(struct kmem_cache *s, char *buf)
3770{
3771 return sprintf(buf, "%d\n", s->size);
3772}
3773SLAB_ATTR_RO(slab_size);
3774
3775static ssize_t align_show(struct kmem_cache *s, char *buf)
3776{
3777 return sprintf(buf, "%d\n", s->align);
3778}
3779SLAB_ATTR_RO(align);
3780
3781static ssize_t object_size_show(struct kmem_cache *s, char *buf)
3782{
3783 return sprintf(buf, "%d\n", s->objsize);
3784}
3785SLAB_ATTR_RO(object_size);
3786
3787static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf)
3788{
Christoph Lameter834f3d12008-04-14 19:11:31 +03003789 return sprintf(buf, "%d\n", oo_objects(s->oo));
Christoph Lameter81819f02007-05-06 14:49:36 -07003790}
3791SLAB_ATTR_RO(objs_per_slab);
3792
Christoph Lameter06b285d2008-04-14 19:11:41 +03003793static ssize_t order_store(struct kmem_cache *s,
3794 const char *buf, size_t length)
3795{
Christoph Lameter0121c6192008-04-29 16:11:12 -07003796 unsigned long order;
3797 int err;
3798
3799 err = strict_strtoul(buf, 10, &order);
3800 if (err)
3801 return err;
Christoph Lameter06b285d2008-04-14 19:11:41 +03003802
3803 if (order > slub_max_order || order < slub_min_order)
3804 return -EINVAL;
3805
3806 calculate_sizes(s, order);
3807 return length;
3808}
3809
Christoph Lameter81819f02007-05-06 14:49:36 -07003810static ssize_t order_show(struct kmem_cache *s, char *buf)
3811{
Christoph Lameter834f3d12008-04-14 19:11:31 +03003812 return sprintf(buf, "%d\n", oo_order(s->oo));
Christoph Lameter81819f02007-05-06 14:49:36 -07003813}
Christoph Lameter06b285d2008-04-14 19:11:41 +03003814SLAB_ATTR(order);
Christoph Lameter81819f02007-05-06 14:49:36 -07003815
3816static ssize_t ctor_show(struct kmem_cache *s, char *buf)
3817{
3818 if (s->ctor) {
3819 int n = sprint_symbol(buf, (unsigned long)s->ctor);
3820
3821 return n + sprintf(buf + n, "\n");
3822 }
3823 return 0;
3824}
3825SLAB_ATTR_RO(ctor);
3826
Christoph Lameter81819f02007-05-06 14:49:36 -07003827static ssize_t aliases_show(struct kmem_cache *s, char *buf)
3828{
3829 return sprintf(buf, "%d\n", s->refcount - 1);
3830}
3831SLAB_ATTR_RO(aliases);
3832
3833static ssize_t slabs_show(struct kmem_cache *s, char *buf)
3834{
Christoph Lameter205ab992008-04-14 19:11:40 +03003835 return show_slab_objects(s, buf, SO_ALL);
Christoph Lameter81819f02007-05-06 14:49:36 -07003836}
3837SLAB_ATTR_RO(slabs);
3838
3839static ssize_t partial_show(struct kmem_cache *s, char *buf)
3840{
Christoph Lameterd9acf4b2008-02-15 15:22:21 -08003841 return show_slab_objects(s, buf, SO_PARTIAL);
Christoph Lameter81819f02007-05-06 14:49:36 -07003842}
3843SLAB_ATTR_RO(partial);
3844
3845static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf)
3846{
Christoph Lameterd9acf4b2008-02-15 15:22:21 -08003847 return show_slab_objects(s, buf, SO_CPU);
Christoph Lameter81819f02007-05-06 14:49:36 -07003848}
3849SLAB_ATTR_RO(cpu_slabs);
3850
3851static ssize_t objects_show(struct kmem_cache *s, char *buf)
3852{
Christoph Lameter205ab992008-04-14 19:11:40 +03003853 return show_slab_objects(s, buf, SO_ALL|SO_OBJECTS);
Christoph Lameter81819f02007-05-06 14:49:36 -07003854}
3855SLAB_ATTR_RO(objects);
3856
Christoph Lameter205ab992008-04-14 19:11:40 +03003857static ssize_t objects_partial_show(struct kmem_cache *s, char *buf)
3858{
3859 return show_slab_objects(s, buf, SO_PARTIAL|SO_OBJECTS);
3860}
3861SLAB_ATTR_RO(objects_partial);
3862
3863static ssize_t total_objects_show(struct kmem_cache *s, char *buf)
3864{
3865 return show_slab_objects(s, buf, SO_ALL|SO_TOTAL);
3866}
3867SLAB_ATTR_RO(total_objects);
3868
Christoph Lameter81819f02007-05-06 14:49:36 -07003869static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf)
3870{
3871 return sprintf(buf, "%d\n", !!(s->flags & SLAB_DEBUG_FREE));
3872}
3873
3874static ssize_t sanity_checks_store(struct kmem_cache *s,
3875 const char *buf, size_t length)
3876{
3877 s->flags &= ~SLAB_DEBUG_FREE;
3878 if (buf[0] == '1')
3879 s->flags |= SLAB_DEBUG_FREE;
3880 return length;
3881}
3882SLAB_ATTR(sanity_checks);
3883
3884static ssize_t trace_show(struct kmem_cache *s, char *buf)
3885{
3886 return sprintf(buf, "%d\n", !!(s->flags & SLAB_TRACE));
3887}
3888
3889static ssize_t trace_store(struct kmem_cache *s, const char *buf,
3890 size_t length)
3891{
3892 s->flags &= ~SLAB_TRACE;
3893 if (buf[0] == '1')
3894 s->flags |= SLAB_TRACE;
3895 return length;
3896}
3897SLAB_ATTR(trace);
3898
3899static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf)
3900{
3901 return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT));
3902}
3903
3904static ssize_t reclaim_account_store(struct kmem_cache *s,
3905 const char *buf, size_t length)
3906{
3907 s->flags &= ~SLAB_RECLAIM_ACCOUNT;
3908 if (buf[0] == '1')
3909 s->flags |= SLAB_RECLAIM_ACCOUNT;
3910 return length;
3911}
3912SLAB_ATTR(reclaim_account);
3913
3914static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf)
3915{
Christoph Lameter5af60832007-05-06 14:49:56 -07003916 return sprintf(buf, "%d\n", !!(s->flags & SLAB_HWCACHE_ALIGN));
Christoph Lameter81819f02007-05-06 14:49:36 -07003917}
3918SLAB_ATTR_RO(hwcache_align);
3919
3920#ifdef CONFIG_ZONE_DMA
3921static ssize_t cache_dma_show(struct kmem_cache *s, char *buf)
3922{
3923 return sprintf(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA));
3924}
3925SLAB_ATTR_RO(cache_dma);
3926#endif
3927
3928static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf)
3929{
3930 return sprintf(buf, "%d\n", !!(s->flags & SLAB_DESTROY_BY_RCU));
3931}
3932SLAB_ATTR_RO(destroy_by_rcu);
3933
3934static ssize_t red_zone_show(struct kmem_cache *s, char *buf)
3935{
3936 return sprintf(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE));
3937}
3938
3939static ssize_t red_zone_store(struct kmem_cache *s,
3940 const char *buf, size_t length)
3941{
3942 if (any_slab_objects(s))
3943 return -EBUSY;
3944
3945 s->flags &= ~SLAB_RED_ZONE;
3946 if (buf[0] == '1')
3947 s->flags |= SLAB_RED_ZONE;
Christoph Lameter06b285d2008-04-14 19:11:41 +03003948 calculate_sizes(s, -1);
Christoph Lameter81819f02007-05-06 14:49:36 -07003949 return length;
3950}
3951SLAB_ATTR(red_zone);
3952
3953static ssize_t poison_show(struct kmem_cache *s, char *buf)
3954{
3955 return sprintf(buf, "%d\n", !!(s->flags & SLAB_POISON));
3956}
3957
3958static ssize_t poison_store(struct kmem_cache *s,
3959 const char *buf, size_t length)
3960{
3961 if (any_slab_objects(s))
3962 return -EBUSY;
3963
3964 s->flags &= ~SLAB_POISON;
3965 if (buf[0] == '1')
3966 s->flags |= SLAB_POISON;
Christoph Lameter06b285d2008-04-14 19:11:41 +03003967 calculate_sizes(s, -1);
Christoph Lameter81819f02007-05-06 14:49:36 -07003968 return length;
3969}
3970SLAB_ATTR(poison);
3971
3972static ssize_t store_user_show(struct kmem_cache *s, char *buf)
3973{
3974 return sprintf(buf, "%d\n", !!(s->flags & SLAB_STORE_USER));
3975}
3976
3977static ssize_t store_user_store(struct kmem_cache *s,
3978 const char *buf, size_t length)
3979{
3980 if (any_slab_objects(s))
3981 return -EBUSY;
3982
3983 s->flags &= ~SLAB_STORE_USER;
3984 if (buf[0] == '1')
3985 s->flags |= SLAB_STORE_USER;
Christoph Lameter06b285d2008-04-14 19:11:41 +03003986 calculate_sizes(s, -1);
Christoph Lameter81819f02007-05-06 14:49:36 -07003987 return length;
3988}
3989SLAB_ATTR(store_user);
3990
Christoph Lameter53e15af2007-05-06 14:49:43 -07003991static ssize_t validate_show(struct kmem_cache *s, char *buf)
3992{
3993 return 0;
3994}
3995
3996static ssize_t validate_store(struct kmem_cache *s,
3997 const char *buf, size_t length)
3998{
Christoph Lameter434e2452007-07-17 04:03:30 -07003999 int ret = -EINVAL;
4000
4001 if (buf[0] == '1') {
4002 ret = validate_slab_cache(s);
4003 if (ret >= 0)
4004 ret = length;
4005 }
4006 return ret;
Christoph Lameter53e15af2007-05-06 14:49:43 -07004007}
4008SLAB_ATTR(validate);
4009
Christoph Lameter2086d262007-05-06 14:49:46 -07004010static ssize_t shrink_show(struct kmem_cache *s, char *buf)
4011{
4012 return 0;
4013}
4014
4015static ssize_t shrink_store(struct kmem_cache *s,
4016 const char *buf, size_t length)
4017{
4018 if (buf[0] == '1') {
4019 int rc = kmem_cache_shrink(s);
4020
4021 if (rc)
4022 return rc;
4023 } else
4024 return -EINVAL;
4025 return length;
4026}
4027SLAB_ATTR(shrink);
4028
Christoph Lameter88a420e2007-05-06 14:49:45 -07004029static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf)
4030{
4031 if (!(s->flags & SLAB_STORE_USER))
4032 return -ENOSYS;
4033 return list_locations(s, buf, TRACK_ALLOC);
4034}
4035SLAB_ATTR_RO(alloc_calls);
4036
4037static ssize_t free_calls_show(struct kmem_cache *s, char *buf)
4038{
4039 if (!(s->flags & SLAB_STORE_USER))
4040 return -ENOSYS;
4041 return list_locations(s, buf, TRACK_FREE);
4042}
4043SLAB_ATTR_RO(free_calls);
4044
Christoph Lameter81819f02007-05-06 14:49:36 -07004045#ifdef CONFIG_NUMA
Christoph Lameter98246012008-01-07 23:20:26 -08004046static ssize_t remote_node_defrag_ratio_show(struct kmem_cache *s, char *buf)
Christoph Lameter81819f02007-05-06 14:49:36 -07004047{
Christoph Lameter98246012008-01-07 23:20:26 -08004048 return sprintf(buf, "%d\n", s->remote_node_defrag_ratio / 10);
Christoph Lameter81819f02007-05-06 14:49:36 -07004049}
4050
Christoph Lameter98246012008-01-07 23:20:26 -08004051static ssize_t remote_node_defrag_ratio_store(struct kmem_cache *s,
Christoph Lameter81819f02007-05-06 14:49:36 -07004052 const char *buf, size_t length)
4053{
Christoph Lameter0121c6192008-04-29 16:11:12 -07004054 unsigned long ratio;
4055 int err;
Christoph Lameter81819f02007-05-06 14:49:36 -07004056
Christoph Lameter0121c6192008-04-29 16:11:12 -07004057 err = strict_strtoul(buf, 10, &ratio);
4058 if (err)
4059 return err;
4060
4061 if (ratio < 100)
4062 s->remote_node_defrag_ratio = ratio * 10;
4063
Christoph Lameter81819f02007-05-06 14:49:36 -07004064 return length;
4065}
Christoph Lameter98246012008-01-07 23:20:26 -08004066SLAB_ATTR(remote_node_defrag_ratio);
Christoph Lameter81819f02007-05-06 14:49:36 -07004067#endif
4068
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004069#ifdef CONFIG_SLUB_STATS
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004070static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si)
4071{
4072 unsigned long sum = 0;
4073 int cpu;
4074 int len;
4075 int *data = kmalloc(nr_cpu_ids * sizeof(int), GFP_KERNEL);
4076
4077 if (!data)
4078 return -ENOMEM;
4079
4080 for_each_online_cpu(cpu) {
4081 unsigned x = get_cpu_slab(s, cpu)->stat[si];
4082
4083 data[cpu] = x;
4084 sum += x;
4085 }
4086
4087 len = sprintf(buf, "%lu", sum);
4088
Christoph Lameter50ef37b2008-04-14 18:52:05 +03004089#ifdef CONFIG_SMP
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004090 for_each_online_cpu(cpu) {
4091 if (data[cpu] && len < PAGE_SIZE - 20)
Christoph Lameter50ef37b2008-04-14 18:52:05 +03004092 len += sprintf(buf + len, " C%d=%u", cpu, data[cpu]);
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004093 }
Christoph Lameter50ef37b2008-04-14 18:52:05 +03004094#endif
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004095 kfree(data);
4096 return len + sprintf(buf + len, "\n");
4097}
4098
4099#define STAT_ATTR(si, text) \
4100static ssize_t text##_show(struct kmem_cache *s, char *buf) \
4101{ \
4102 return show_stat(s, buf, si); \
4103} \
4104SLAB_ATTR_RO(text); \
4105
4106STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath);
4107STAT_ATTR(ALLOC_SLOWPATH, alloc_slowpath);
4108STAT_ATTR(FREE_FASTPATH, free_fastpath);
4109STAT_ATTR(FREE_SLOWPATH, free_slowpath);
4110STAT_ATTR(FREE_FROZEN, free_frozen);
4111STAT_ATTR(FREE_ADD_PARTIAL, free_add_partial);
4112STAT_ATTR(FREE_REMOVE_PARTIAL, free_remove_partial);
4113STAT_ATTR(ALLOC_FROM_PARTIAL, alloc_from_partial);
4114STAT_ATTR(ALLOC_SLAB, alloc_slab);
4115STAT_ATTR(ALLOC_REFILL, alloc_refill);
4116STAT_ATTR(FREE_SLAB, free_slab);
4117STAT_ATTR(CPUSLAB_FLUSH, cpuslab_flush);
4118STAT_ATTR(DEACTIVATE_FULL, deactivate_full);
4119STAT_ATTR(DEACTIVATE_EMPTY, deactivate_empty);
4120STAT_ATTR(DEACTIVATE_TO_HEAD, deactivate_to_head);
4121STAT_ATTR(DEACTIVATE_TO_TAIL, deactivate_to_tail);
4122STAT_ATTR(DEACTIVATE_REMOTE_FREES, deactivate_remote_frees);
Christoph Lameter65c33762008-04-14 19:11:40 +03004123STAT_ATTR(ORDER_FALLBACK, order_fallback);
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004124#endif
4125
Pekka Enberg06428782008-01-07 23:20:27 -08004126static struct attribute *slab_attrs[] = {
Christoph Lameter81819f02007-05-06 14:49:36 -07004127 &slab_size_attr.attr,
4128 &object_size_attr.attr,
4129 &objs_per_slab_attr.attr,
4130 &order_attr.attr,
4131 &objects_attr.attr,
Christoph Lameter205ab992008-04-14 19:11:40 +03004132 &objects_partial_attr.attr,
4133 &total_objects_attr.attr,
Christoph Lameter81819f02007-05-06 14:49:36 -07004134 &slabs_attr.attr,
4135 &partial_attr.attr,
4136 &cpu_slabs_attr.attr,
4137 &ctor_attr.attr,
Christoph Lameter81819f02007-05-06 14:49:36 -07004138 &aliases_attr.attr,
4139 &align_attr.attr,
4140 &sanity_checks_attr.attr,
4141 &trace_attr.attr,
4142 &hwcache_align_attr.attr,
4143 &reclaim_account_attr.attr,
4144 &destroy_by_rcu_attr.attr,
4145 &red_zone_attr.attr,
4146 &poison_attr.attr,
4147 &store_user_attr.attr,
Christoph Lameter53e15af2007-05-06 14:49:43 -07004148 &validate_attr.attr,
Christoph Lameter2086d262007-05-06 14:49:46 -07004149 &shrink_attr.attr,
Christoph Lameter88a420e2007-05-06 14:49:45 -07004150 &alloc_calls_attr.attr,
4151 &free_calls_attr.attr,
Christoph Lameter81819f02007-05-06 14:49:36 -07004152#ifdef CONFIG_ZONE_DMA
4153 &cache_dma_attr.attr,
4154#endif
4155#ifdef CONFIG_NUMA
Christoph Lameter98246012008-01-07 23:20:26 -08004156 &remote_node_defrag_ratio_attr.attr,
Christoph Lameter81819f02007-05-06 14:49:36 -07004157#endif
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004158#ifdef CONFIG_SLUB_STATS
4159 &alloc_fastpath_attr.attr,
4160 &alloc_slowpath_attr.attr,
4161 &free_fastpath_attr.attr,
4162 &free_slowpath_attr.attr,
4163 &free_frozen_attr.attr,
4164 &free_add_partial_attr.attr,
4165 &free_remove_partial_attr.attr,
4166 &alloc_from_partial_attr.attr,
4167 &alloc_slab_attr.attr,
4168 &alloc_refill_attr.attr,
4169 &free_slab_attr.attr,
4170 &cpuslab_flush_attr.attr,
4171 &deactivate_full_attr.attr,
4172 &deactivate_empty_attr.attr,
4173 &deactivate_to_head_attr.attr,
4174 &deactivate_to_tail_attr.attr,
4175 &deactivate_remote_frees_attr.attr,
Christoph Lameter65c33762008-04-14 19:11:40 +03004176 &order_fallback_attr.attr,
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004177#endif
Christoph Lameter81819f02007-05-06 14:49:36 -07004178 NULL
4179};
4180
4181static struct attribute_group slab_attr_group = {
4182 .attrs = slab_attrs,
4183};
4184
4185static ssize_t slab_attr_show(struct kobject *kobj,
4186 struct attribute *attr,
4187 char *buf)
4188{
4189 struct slab_attribute *attribute;
4190 struct kmem_cache *s;
4191 int err;
4192
4193 attribute = to_slab_attr(attr);
4194 s = to_slab(kobj);
4195
4196 if (!attribute->show)
4197 return -EIO;
4198
4199 err = attribute->show(s, buf);
4200
4201 return err;
4202}
4203
4204static ssize_t slab_attr_store(struct kobject *kobj,
4205 struct attribute *attr,
4206 const char *buf, size_t len)
4207{
4208 struct slab_attribute *attribute;
4209 struct kmem_cache *s;
4210 int err;
4211
4212 attribute = to_slab_attr(attr);
4213 s = to_slab(kobj);
4214
4215 if (!attribute->store)
4216 return -EIO;
4217
4218 err = attribute->store(s, buf, len);
4219
4220 return err;
4221}
4222
Christoph Lameter151c6022008-01-07 22:29:05 -08004223static void kmem_cache_release(struct kobject *kobj)
4224{
4225 struct kmem_cache *s = to_slab(kobj);
4226
4227 kfree(s);
4228}
4229
Christoph Lameter81819f02007-05-06 14:49:36 -07004230static struct sysfs_ops slab_sysfs_ops = {
4231 .show = slab_attr_show,
4232 .store = slab_attr_store,
4233};
4234
4235static struct kobj_type slab_ktype = {
4236 .sysfs_ops = &slab_sysfs_ops,
Christoph Lameter151c6022008-01-07 22:29:05 -08004237 .release = kmem_cache_release
Christoph Lameter81819f02007-05-06 14:49:36 -07004238};
4239
4240static int uevent_filter(struct kset *kset, struct kobject *kobj)
4241{
4242 struct kobj_type *ktype = get_ktype(kobj);
4243
4244 if (ktype == &slab_ktype)
4245 return 1;
4246 return 0;
4247}
4248
4249static struct kset_uevent_ops slab_uevent_ops = {
4250 .filter = uevent_filter,
4251};
4252
Greg Kroah-Hartman27c3a312007-11-01 09:29:06 -06004253static struct kset *slab_kset;
Christoph Lameter81819f02007-05-06 14:49:36 -07004254
4255#define ID_STR_LENGTH 64
4256
4257/* Create a unique string id for a slab cache:
Christoph Lameter6446faa2008-02-15 23:45:26 -08004258 *
4259 * Format :[flags-]size
Christoph Lameter81819f02007-05-06 14:49:36 -07004260 */
4261static char *create_unique_id(struct kmem_cache *s)
4262{
4263 char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL);
4264 char *p = name;
4265
4266 BUG_ON(!name);
4267
4268 *p++ = ':';
4269 /*
4270 * First flags affecting slabcache operations. We will only
4271 * get here for aliasable slabs so we do not need to support
4272 * too many flags. The flags here must cover all flags that
4273 * are matched during merging to guarantee that the id is
4274 * unique.
4275 */
4276 if (s->flags & SLAB_CACHE_DMA)
4277 *p++ = 'd';
4278 if (s->flags & SLAB_RECLAIM_ACCOUNT)
4279 *p++ = 'a';
4280 if (s->flags & SLAB_DEBUG_FREE)
4281 *p++ = 'F';
4282 if (p != name + 1)
4283 *p++ = '-';
4284 p += sprintf(p, "%07d", s->size);
4285 BUG_ON(p > name + ID_STR_LENGTH - 1);
4286 return name;
4287}
4288
4289static int sysfs_slab_add(struct kmem_cache *s)
4290{
4291 int err;
4292 const char *name;
4293 int unmergeable;
4294
4295 if (slab_state < SYSFS)
4296 /* Defer until later */
4297 return 0;
4298
4299 unmergeable = slab_unmergeable(s);
4300 if (unmergeable) {
4301 /*
4302 * Slabcache can never be merged so we can use the name proper.
4303 * This is typically the case for debug situations. In that
4304 * case we can catch duplicate names easily.
4305 */
Greg Kroah-Hartman27c3a312007-11-01 09:29:06 -06004306 sysfs_remove_link(&slab_kset->kobj, s->name);
Christoph Lameter81819f02007-05-06 14:49:36 -07004307 name = s->name;
4308 } else {
4309 /*
4310 * Create a unique name for the slab as a target
4311 * for the symlinks.
4312 */
4313 name = create_unique_id(s);
4314 }
4315
Greg Kroah-Hartman27c3a312007-11-01 09:29:06 -06004316 s->kobj.kset = slab_kset;
Greg Kroah-Hartman1eada112007-12-17 23:05:35 -07004317 err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, name);
4318 if (err) {
4319 kobject_put(&s->kobj);
Christoph Lameter81819f02007-05-06 14:49:36 -07004320 return err;
Greg Kroah-Hartman1eada112007-12-17 23:05:35 -07004321 }
Christoph Lameter81819f02007-05-06 14:49:36 -07004322
4323 err = sysfs_create_group(&s->kobj, &slab_attr_group);
4324 if (err)
4325 return err;
4326 kobject_uevent(&s->kobj, KOBJ_ADD);
4327 if (!unmergeable) {
4328 /* Setup first alias */
4329 sysfs_slab_alias(s, s->name);
4330 kfree(name);
4331 }
4332 return 0;
4333}
4334
4335static void sysfs_slab_remove(struct kmem_cache *s)
4336{
4337 kobject_uevent(&s->kobj, KOBJ_REMOVE);
4338 kobject_del(&s->kobj);
Christoph Lameter151c6022008-01-07 22:29:05 -08004339 kobject_put(&s->kobj);
Christoph Lameter81819f02007-05-06 14:49:36 -07004340}
4341
4342/*
4343 * Need to buffer aliases during bootup until sysfs becomes
4344 * available lest we loose that information.
4345 */
4346struct saved_alias {
4347 struct kmem_cache *s;
4348 const char *name;
4349 struct saved_alias *next;
4350};
4351
Adrian Bunk5af328a2007-07-17 04:03:27 -07004352static struct saved_alias *alias_list;
Christoph Lameter81819f02007-05-06 14:49:36 -07004353
4354static int sysfs_slab_alias(struct kmem_cache *s, const char *name)
4355{
4356 struct saved_alias *al;
4357
4358 if (slab_state == SYSFS) {
4359 /*
4360 * If we have a leftover link then remove it.
4361 */
Greg Kroah-Hartman27c3a312007-11-01 09:29:06 -06004362 sysfs_remove_link(&slab_kset->kobj, name);
4363 return sysfs_create_link(&slab_kset->kobj, &s->kobj, name);
Christoph Lameter81819f02007-05-06 14:49:36 -07004364 }
4365
4366 al = kmalloc(sizeof(struct saved_alias), GFP_KERNEL);
4367 if (!al)
4368 return -ENOMEM;
4369
4370 al->s = s;
4371 al->name = name;
4372 al->next = alias_list;
4373 alias_list = al;
4374 return 0;
4375}
4376
4377static int __init slab_sysfs_init(void)
4378{
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07004379 struct kmem_cache *s;
Christoph Lameter81819f02007-05-06 14:49:36 -07004380 int err;
4381
Greg Kroah-Hartman0ff21e42007-11-06 10:36:58 -08004382 slab_kset = kset_create_and_add("slab", &slab_uevent_ops, kernel_kobj);
Greg Kroah-Hartman27c3a312007-11-01 09:29:06 -06004383 if (!slab_kset) {
Christoph Lameter81819f02007-05-06 14:49:36 -07004384 printk(KERN_ERR "Cannot register slab subsystem.\n");
4385 return -ENOSYS;
4386 }
4387
Christoph Lameter26a7bd02007-05-09 02:32:39 -07004388 slab_state = SYSFS;
4389
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07004390 list_for_each_entry(s, &slab_caches, list) {
Christoph Lameter26a7bd02007-05-09 02:32:39 -07004391 err = sysfs_slab_add(s);
Christoph Lameter5d540fb2007-08-30 23:56:26 -07004392 if (err)
4393 printk(KERN_ERR "SLUB: Unable to add boot slab %s"
4394 " to sysfs\n", s->name);
Christoph Lameter26a7bd02007-05-09 02:32:39 -07004395 }
Christoph Lameter81819f02007-05-06 14:49:36 -07004396
4397 while (alias_list) {
4398 struct saved_alias *al = alias_list;
4399
4400 alias_list = alias_list->next;
4401 err = sysfs_slab_alias(al->s, al->name);
Christoph Lameter5d540fb2007-08-30 23:56:26 -07004402 if (err)
4403 printk(KERN_ERR "SLUB: Unable to add boot slab alias"
4404 " %s to sysfs\n", s->name);
Christoph Lameter81819f02007-05-06 14:49:36 -07004405 kfree(al);
4406 }
4407
4408 resiliency_test();
4409 return 0;
4410}
4411
4412__initcall(slab_sysfs_init);
Christoph Lameter81819f02007-05-06 14:49:36 -07004413#endif
Pekka J Enberg57ed3ed2008-01-01 17:23:28 +01004414
4415/*
4416 * The /proc/slabinfo ABI
4417 */
Linus Torvalds158a9622008-01-02 13:04:48 -08004418#ifdef CONFIG_SLABINFO
4419
Christoph Lameter0121c6192008-04-29 16:11:12 -07004420ssize_t slabinfo_write(struct file *file, const char __user *buffer,
4421 size_t count, loff_t *ppos)
Linus Torvalds158a9622008-01-02 13:04:48 -08004422{
4423 return -EINVAL;
4424}
4425
Pekka J Enberg57ed3ed2008-01-01 17:23:28 +01004426
4427static void print_slabinfo_header(struct seq_file *m)
4428{
4429 seq_puts(m, "slabinfo - version: 2.1\n");
4430 seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
4431 "<objperslab> <pagesperslab>");
4432 seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
4433 seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
4434 seq_putc(m, '\n');
4435}
4436
4437static void *s_start(struct seq_file *m, loff_t *pos)
4438{
4439 loff_t n = *pos;
4440
4441 down_read(&slub_lock);
4442 if (!n)
4443 print_slabinfo_header(m);
4444
4445 return seq_list_start(&slab_caches, *pos);
4446}
4447
4448static void *s_next(struct seq_file *m, void *p, loff_t *pos)
4449{
4450 return seq_list_next(p, &slab_caches, pos);
4451}
4452
4453static void s_stop(struct seq_file *m, void *p)
4454{
4455 up_read(&slub_lock);
4456}
4457
4458static int s_show(struct seq_file *m, void *p)
4459{
4460 unsigned long nr_partials = 0;
4461 unsigned long nr_slabs = 0;
4462 unsigned long nr_inuse = 0;
Christoph Lameter205ab992008-04-14 19:11:40 +03004463 unsigned long nr_objs = 0;
4464 unsigned long nr_free = 0;
Pekka J Enberg57ed3ed2008-01-01 17:23:28 +01004465 struct kmem_cache *s;
4466 int node;
4467
4468 s = list_entry(p, struct kmem_cache, list);
4469
4470 for_each_online_node(node) {
4471 struct kmem_cache_node *n = get_node(s, node);
4472
4473 if (!n)
4474 continue;
4475
4476 nr_partials += n->nr_partial;
4477 nr_slabs += atomic_long_read(&n->nr_slabs);
Christoph Lameter205ab992008-04-14 19:11:40 +03004478 nr_objs += atomic_long_read(&n->total_objects);
4479 nr_free += count_partial(n, count_free);
Pekka J Enberg57ed3ed2008-01-01 17:23:28 +01004480 }
4481
Christoph Lameter205ab992008-04-14 19:11:40 +03004482 nr_inuse = nr_objs - nr_free;
Pekka J Enberg57ed3ed2008-01-01 17:23:28 +01004483
4484 seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", s->name, nr_inuse,
Christoph Lameter834f3d12008-04-14 19:11:31 +03004485 nr_objs, s->size, oo_objects(s->oo),
4486 (1 << oo_order(s->oo)));
Pekka J Enberg57ed3ed2008-01-01 17:23:28 +01004487 seq_printf(m, " : tunables %4u %4u %4u", 0, 0, 0);
4488 seq_printf(m, " : slabdata %6lu %6lu %6lu", nr_slabs, nr_slabs,
4489 0UL);
4490 seq_putc(m, '\n');
4491 return 0;
4492}
4493
4494const struct seq_operations slabinfo_op = {
4495 .start = s_start,
4496 .next = s_next,
4497 .stop = s_stop,
4498 .show = s_show,
4499};
4500
Linus Torvalds158a9622008-01-02 13:04:48 -08004501#endif /* CONFIG_SLABINFO */