blob: 0987d1cd943cc88d626a7d1b1097ba1f83243591 [file] [log] [blame]
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 *
8 * (C) 2007 SGI, Christoph Lameter <clameter@sgi.com>
9 */
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#define FROZEN (1 << PG_active)
106
107#ifdef CONFIG_SLUB_DEBUG
108#define SLABDEBUG (1 << PG_error)
109#else
110#define SLABDEBUG 0
111#endif
112
Christoph Lameter4b6f0752007-05-16 22:10:53 -0700113static inline int SlabFrozen(struct page *page)
114{
Christoph Lameter5577bd82007-05-16 22:10:56 -0700115 return page->flags & FROZEN;
Christoph Lameter4b6f0752007-05-16 22:10:53 -0700116}
117
118static inline void SetSlabFrozen(struct page *page)
119{
Christoph Lameter5577bd82007-05-16 22:10:56 -0700120 page->flags |= FROZEN;
Christoph Lameter4b6f0752007-05-16 22:10:53 -0700121}
122
123static inline void ClearSlabFrozen(struct page *page)
124{
Christoph Lameter5577bd82007-05-16 22:10:56 -0700125 page->flags &= ~FROZEN;
Christoph Lameter4b6f0752007-05-16 22:10:53 -0700126}
127
Christoph Lameter35e5d7e2007-05-09 02:32:42 -0700128static inline int SlabDebug(struct page *page)
129{
Christoph Lameter5577bd82007-05-16 22:10:56 -0700130 return page->flags & SLABDEBUG;
Christoph Lameter35e5d7e2007-05-09 02:32:42 -0700131}
132
133static inline void SetSlabDebug(struct page *page)
134{
Christoph Lameter5577bd82007-05-16 22:10:56 -0700135 page->flags |= SLABDEBUG;
Christoph Lameter35e5d7e2007-05-09 02:32:42 -0700136}
137
138static inline void ClearSlabDebug(struct page *page)
139{
Christoph Lameter5577bd82007-05-16 22:10:56 -0700140 page->flags &= ~SLABDEBUG;
Christoph Lameter35e5d7e2007-05-09 02:32:42 -0700141}
142
Christoph Lameter81819f02007-05-06 14:49:36 -0700143/*
144 * Issues still to be resolved:
145 *
Christoph Lameter81819f02007-05-06 14:49:36 -0700146 * - Support PAGE_ALLOC_DEBUG. Should be easy to do.
147 *
Christoph Lameter81819f02007-05-06 14:49:36 -0700148 * - Variable sizing of the per node arrays
149 */
150
151/* Enable to test recovery from slab corruption on boot */
152#undef SLUB_RESILIENCY_TEST
153
Christoph Lameter81819f02007-05-06 14:49:36 -0700154/*
Christoph Lameter2086d262007-05-06 14:49:46 -0700155 * Mininum number of partial slabs. These will be left on the partial
156 * lists even if they are empty. kmem_cache_shrink may reclaim them.
157 */
Christoph Lameter76be8952007-12-21 14:37:37 -0800158#define MIN_PARTIAL 5
Christoph Lametere95eed52007-05-06 14:49:44 -0700159
Christoph Lameter2086d262007-05-06 14:49:46 -0700160/*
161 * Maximum number of desirable partial slabs.
162 * The existence of more partial slabs makes kmem_cache_shrink
163 * sort the partial list by the number of objects in the.
164 */
165#define MAX_PARTIAL 10
166
Christoph Lameter81819f02007-05-06 14:49:36 -0700167#define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \
168 SLAB_POISON | SLAB_STORE_USER)
Christoph Lameter672bba32007-05-09 02:32:39 -0700169
Christoph Lameter81819f02007-05-06 14:49:36 -0700170/*
171 * Set of flags that will prevent slab merging
172 */
173#define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
174 SLAB_TRACE | SLAB_DESTROY_BY_RCU)
175
176#define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \
177 SLAB_CACHE_DMA)
178
179#ifndef ARCH_KMALLOC_MINALIGN
Christoph Lameter47bfdc02007-05-06 14:49:37 -0700180#define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
Christoph Lameter81819f02007-05-06 14:49:36 -0700181#endif
182
183#ifndef ARCH_SLAB_MINALIGN
Christoph Lameter47bfdc02007-05-06 14:49:37 -0700184#define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
Christoph Lameter81819f02007-05-06 14:49:36 -0700185#endif
186
187/* Internal SLUB flags */
Christoph Lameter1ceef402007-08-07 15:11:48 -0700188#define __OBJECT_POISON 0x80000000 /* Poison object */
189#define __SYSFS_ADD_DEFERRED 0x40000000 /* Not yet visible via sysfs */
Christoph Lameter81819f02007-05-06 14:49:36 -0700190
191static int kmem_size = sizeof(struct kmem_cache);
192
193#ifdef CONFIG_SMP
194static struct notifier_block slab_notifier;
195#endif
196
197static enum {
198 DOWN, /* No slab functionality available */
199 PARTIAL, /* kmem_cache_open() works but kmalloc does not */
Christoph Lameter672bba32007-05-09 02:32:39 -0700200 UP, /* Everything works but does not show up in sysfs */
Christoph Lameter81819f02007-05-06 14:49:36 -0700201 SYSFS /* Sysfs up */
202} slab_state = DOWN;
203
204/* A list of all slab caches on the system */
205static DECLARE_RWSEM(slub_lock);
Adrian Bunk5af328a2007-07-17 04:03:27 -0700206static LIST_HEAD(slab_caches);
Christoph Lameter81819f02007-05-06 14:49:36 -0700207
Christoph Lameter02cbc872007-05-09 02:32:43 -0700208/*
209 * Tracking user of a slab.
210 */
211struct track {
212 void *addr; /* Called from address */
213 int cpu; /* Was running on cpu */
214 int pid; /* Pid context */
215 unsigned long when; /* When did the operation occur */
216};
217
218enum track_item { TRACK_ALLOC, TRACK_FREE };
219
Christoph Lameterf6acb632008-04-29 16:16:06 -0700220#ifdef CONFIG_SLUB_DEBUG
Christoph Lameter81819f02007-05-06 14:49:36 -0700221static int sysfs_slab_add(struct kmem_cache *);
222static int sysfs_slab_alias(struct kmem_cache *, const char *);
223static void sysfs_slab_remove(struct kmem_cache *);
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800224
Christoph Lameter81819f02007-05-06 14:49:36 -0700225#else
Christoph Lameter0c710012007-07-17 04:03:24 -0700226static inline int sysfs_slab_add(struct kmem_cache *s) { return 0; }
227static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p)
228 { return 0; }
Christoph Lameter151c6022008-01-07 22:29:05 -0800229static inline void sysfs_slab_remove(struct kmem_cache *s)
230{
231 kfree(s);
232}
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800233
Christoph Lameter81819f02007-05-06 14:49:36 -0700234#endif
235
Christoph Lameter8ff12cf2008-02-07 17:47:41 -0800236static inline void stat(struct kmem_cache_cpu *c, enum stat_item si)
237{
238#ifdef CONFIG_SLUB_STATS
239 c->stat[si]++;
240#endif
241}
242
Christoph Lameter81819f02007-05-06 14:49:36 -0700243/********************************************************************
244 * Core slab cache functions
245 *******************************************************************/
246
247int slab_is_available(void)
248{
249 return slab_state >= UP;
250}
251
252static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
253{
254#ifdef CONFIG_NUMA
255 return s->node[node];
256#else
257 return &s->local_node;
258#endif
259}
260
Christoph Lameterdfb4f092007-10-16 01:26:05 -0700261static inline struct kmem_cache_cpu *get_cpu_slab(struct kmem_cache *s, int cpu)
262{
Christoph Lameter4c93c3552007-10-16 01:26:08 -0700263#ifdef CONFIG_SMP
264 return s->cpu_slab[cpu];
265#else
266 return &s->cpu_slab;
267#endif
Christoph Lameterdfb4f092007-10-16 01:26:05 -0700268}
269
Christoph Lameter6446faa2008-02-15 23:45:26 -0800270/* Verify that a pointer has an address that is valid within a slab page */
Christoph Lameter02cbc872007-05-09 02:32:43 -0700271static inline int check_valid_pointer(struct kmem_cache *s,
272 struct page *page, const void *object)
273{
274 void *base;
275
Christoph Lametera973e9d2008-03-01 13:40:44 -0800276 if (!object)
Christoph Lameter02cbc872007-05-09 02:32:43 -0700277 return 1;
278
Christoph Lametera973e9d2008-03-01 13:40:44 -0800279 base = page_address(page);
Christoph Lameter39b26462008-04-14 19:11:30 +0300280 if (object < base || object >= base + page->objects * s->size ||
Christoph Lameter02cbc872007-05-09 02:32:43 -0700281 (object - base) % s->size) {
282 return 0;
283 }
284
285 return 1;
286}
287
Christoph Lameter81819f02007-05-06 14:49:36 -0700288/*
Christoph Lameter7656c722007-05-09 02:32:40 -0700289 * Slow version of get and set free pointer.
290 *
291 * This version requires touching the cache lines of kmem_cache which
292 * we avoid to do in the fast alloc free paths. There we obtain the offset
293 * from the page struct.
294 */
295static inline void *get_freepointer(struct kmem_cache *s, void *object)
296{
297 return *(void **)(object + s->offset);
298}
299
300static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
301{
302 *(void **)(object + s->offset) = fp;
303}
304
305/* Loop over all objects in a slab */
Christoph Lameter224a88b2008-04-14 19:11:31 +0300306#define for_each_object(__p, __s, __addr, __objects) \
307 for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\
Christoph Lameter7656c722007-05-09 02:32:40 -0700308 __p += (__s)->size)
309
310/* Scan freelist */
311#define for_each_free_object(__p, __s, __free) \
Christoph Lametera973e9d2008-03-01 13:40:44 -0800312 for (__p = (__free); __p; __p = get_freepointer((__s), __p))
Christoph Lameter7656c722007-05-09 02:32:40 -0700313
314/* Determine object index from a given position */
315static inline int slab_index(void *p, struct kmem_cache *s, void *addr)
316{
317 return (p - addr) / s->size;
318}
319
Christoph Lameter834f3d12008-04-14 19:11:31 +0300320static inline struct kmem_cache_order_objects oo_make(int order,
321 unsigned long size)
322{
323 struct kmem_cache_order_objects x = {
324 (order << 16) + (PAGE_SIZE << order) / size
325 };
326
327 return x;
328}
329
330static inline int oo_order(struct kmem_cache_order_objects x)
331{
332 return x.x >> 16;
333}
334
335static inline int oo_objects(struct kmem_cache_order_objects x)
336{
337 return x.x & ((1 << 16) - 1);
338}
339
Christoph Lameter41ecc552007-05-09 02:32:44 -0700340#ifdef CONFIG_SLUB_DEBUG
341/*
342 * Debug settings:
343 */
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700344#ifdef CONFIG_SLUB_DEBUG_ON
345static int slub_debug = DEBUG_DEFAULT_FLAGS;
346#else
Christoph Lameter41ecc552007-05-09 02:32:44 -0700347static int slub_debug;
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700348#endif
Christoph Lameter41ecc552007-05-09 02:32:44 -0700349
350static char *slub_debug_slabs;
351
Christoph Lameter7656c722007-05-09 02:32:40 -0700352/*
Christoph Lameter81819f02007-05-06 14:49:36 -0700353 * Object debugging
354 */
355static void print_section(char *text, u8 *addr, unsigned int length)
356{
357 int i, offset;
358 int newline = 1;
359 char ascii[17];
360
361 ascii[16] = 0;
362
363 for (i = 0; i < length; i++) {
364 if (newline) {
Christoph Lameter24922682007-07-17 04:03:18 -0700365 printk(KERN_ERR "%8s 0x%p: ", text, addr + i);
Christoph Lameter81819f02007-05-06 14:49:36 -0700366 newline = 0;
367 }
Pekka Enberg06428782008-01-07 23:20:27 -0800368 printk(KERN_CONT " %02x", addr[i]);
Christoph Lameter81819f02007-05-06 14:49:36 -0700369 offset = i % 16;
370 ascii[offset] = isgraph(addr[i]) ? addr[i] : '.';
371 if (offset == 15) {
Pekka Enberg06428782008-01-07 23:20:27 -0800372 printk(KERN_CONT " %s\n", ascii);
Christoph Lameter81819f02007-05-06 14:49:36 -0700373 newline = 1;
374 }
375 }
376 if (!newline) {
377 i %= 16;
378 while (i < 16) {
Pekka Enberg06428782008-01-07 23:20:27 -0800379 printk(KERN_CONT " ");
Christoph Lameter81819f02007-05-06 14:49:36 -0700380 ascii[i] = ' ';
381 i++;
382 }
Pekka Enberg06428782008-01-07 23:20:27 -0800383 printk(KERN_CONT " %s\n", ascii);
Christoph Lameter81819f02007-05-06 14:49:36 -0700384 }
385}
386
Christoph Lameter81819f02007-05-06 14:49:36 -0700387static struct track *get_track(struct kmem_cache *s, void *object,
388 enum track_item alloc)
389{
390 struct track *p;
391
392 if (s->offset)
393 p = object + s->offset + sizeof(void *);
394 else
395 p = object + s->inuse;
396
397 return p + alloc;
398}
399
400static void set_track(struct kmem_cache *s, void *object,
401 enum track_item alloc, void *addr)
402{
403 struct track *p;
404
405 if (s->offset)
406 p = object + s->offset + sizeof(void *);
407 else
408 p = object + s->inuse;
409
410 p += alloc;
411 if (addr) {
412 p->addr = addr;
413 p->cpu = smp_processor_id();
414 p->pid = current ? current->pid : -1;
415 p->when = jiffies;
416 } else
417 memset(p, 0, sizeof(struct track));
418}
419
Christoph Lameter81819f02007-05-06 14:49:36 -0700420static void init_tracking(struct kmem_cache *s, void *object)
421{
Christoph Lameter24922682007-07-17 04:03:18 -0700422 if (!(s->flags & SLAB_STORE_USER))
423 return;
424
425 set_track(s, object, TRACK_FREE, NULL);
426 set_track(s, object, TRACK_ALLOC, NULL);
Christoph Lameter81819f02007-05-06 14:49:36 -0700427}
428
429static void print_track(const char *s, struct track *t)
430{
431 if (!t->addr)
432 return;
433
Christoph Lameter24922682007-07-17 04:03:18 -0700434 printk(KERN_ERR "INFO: %s in ", s);
Christoph Lameter81819f02007-05-06 14:49:36 -0700435 __print_symbol("%s", (unsigned long)t->addr);
Christoph Lameter24922682007-07-17 04:03:18 -0700436 printk(" age=%lu cpu=%u pid=%d\n", jiffies - t->when, t->cpu, t->pid);
Christoph Lameter81819f02007-05-06 14:49:36 -0700437}
438
Christoph Lameter24922682007-07-17 04:03:18 -0700439static void print_tracking(struct kmem_cache *s, void *object)
440{
441 if (!(s->flags & SLAB_STORE_USER))
442 return;
443
444 print_track("Allocated", get_track(s, object, TRACK_ALLOC));
445 print_track("Freed", get_track(s, object, TRACK_FREE));
446}
447
448static void print_page_info(struct page *page)
449{
Christoph Lameter39b26462008-04-14 19:11:30 +0300450 printk(KERN_ERR "INFO: Slab 0x%p objects=%u used=%u fp=0x%p flags=0x%04lx\n",
451 page, page->objects, page->inuse, page->freelist, page->flags);
Christoph Lameter24922682007-07-17 04:03:18 -0700452
453}
454
455static void slab_bug(struct kmem_cache *s, char *fmt, ...)
456{
457 va_list args;
458 char buf[100];
459
460 va_start(args, fmt);
461 vsnprintf(buf, sizeof(buf), fmt, args);
462 va_end(args);
463 printk(KERN_ERR "========================================"
464 "=====================================\n");
465 printk(KERN_ERR "BUG %s: %s\n", s->name, buf);
466 printk(KERN_ERR "----------------------------------------"
467 "-------------------------------------\n\n");
468}
469
470static void slab_fix(struct kmem_cache *s, char *fmt, ...)
471{
472 va_list args;
473 char buf[100];
474
475 va_start(args, fmt);
476 vsnprintf(buf, sizeof(buf), fmt, args);
477 va_end(args);
478 printk(KERN_ERR "FIX %s: %s\n", s->name, buf);
479}
480
481static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p)
Christoph Lameter81819f02007-05-06 14:49:36 -0700482{
483 unsigned int off; /* Offset of last byte */
Christoph Lametera973e9d2008-03-01 13:40:44 -0800484 u8 *addr = page_address(page);
Christoph Lameter24922682007-07-17 04:03:18 -0700485
486 print_tracking(s, p);
487
488 print_page_info(page);
489
490 printk(KERN_ERR "INFO: Object 0x%p @offset=%tu fp=0x%p\n\n",
491 p, p - addr, get_freepointer(s, p));
492
493 if (p > addr + 16)
494 print_section("Bytes b4", p - 16, 16);
495
496 print_section("Object", p, min(s->objsize, 128));
Christoph Lameter81819f02007-05-06 14:49:36 -0700497
498 if (s->flags & SLAB_RED_ZONE)
499 print_section("Redzone", p + s->objsize,
500 s->inuse - s->objsize);
501
Christoph Lameter81819f02007-05-06 14:49:36 -0700502 if (s->offset)
503 off = s->offset + sizeof(void *);
504 else
505 off = s->inuse;
506
Christoph Lameter24922682007-07-17 04:03:18 -0700507 if (s->flags & SLAB_STORE_USER)
Christoph Lameter81819f02007-05-06 14:49:36 -0700508 off += 2 * sizeof(struct track);
Christoph Lameter81819f02007-05-06 14:49:36 -0700509
510 if (off != s->size)
511 /* Beginning of the filler is the free pointer */
Christoph Lameter24922682007-07-17 04:03:18 -0700512 print_section("Padding", p + off, s->size - off);
513
514 dump_stack();
Christoph Lameter81819f02007-05-06 14:49:36 -0700515}
516
517static void object_err(struct kmem_cache *s, struct page *page,
518 u8 *object, char *reason)
519{
Christoph Lameter3dc50632008-04-23 12:28:01 -0700520 slab_bug(s, "%s", reason);
Christoph Lameter24922682007-07-17 04:03:18 -0700521 print_trailer(s, page, object);
Christoph Lameter81819f02007-05-06 14:49:36 -0700522}
523
Christoph Lameter24922682007-07-17 04:03:18 -0700524static void slab_err(struct kmem_cache *s, struct page *page, char *fmt, ...)
Christoph Lameter81819f02007-05-06 14:49:36 -0700525{
526 va_list args;
527 char buf[100];
528
Christoph Lameter24922682007-07-17 04:03:18 -0700529 va_start(args, fmt);
530 vsnprintf(buf, sizeof(buf), fmt, args);
Christoph Lameter81819f02007-05-06 14:49:36 -0700531 va_end(args);
Christoph Lameter3dc50632008-04-23 12:28:01 -0700532 slab_bug(s, "%s", buf);
Christoph Lameter24922682007-07-17 04:03:18 -0700533 print_page_info(page);
Christoph Lameter81819f02007-05-06 14:49:36 -0700534 dump_stack();
535}
536
537static void init_object(struct kmem_cache *s, void *object, int active)
538{
539 u8 *p = object;
540
541 if (s->flags & __OBJECT_POISON) {
542 memset(p, POISON_FREE, s->objsize - 1);
Pekka Enberg06428782008-01-07 23:20:27 -0800543 p[s->objsize - 1] = POISON_END;
Christoph Lameter81819f02007-05-06 14:49:36 -0700544 }
545
546 if (s->flags & SLAB_RED_ZONE)
547 memset(p + s->objsize,
548 active ? SLUB_RED_ACTIVE : SLUB_RED_INACTIVE,
549 s->inuse - s->objsize);
550}
551
Christoph Lameter24922682007-07-17 04:03:18 -0700552static u8 *check_bytes(u8 *start, unsigned int value, unsigned int bytes)
Christoph Lameter81819f02007-05-06 14:49:36 -0700553{
554 while (bytes) {
555 if (*start != (u8)value)
Christoph Lameter24922682007-07-17 04:03:18 -0700556 return start;
Christoph Lameter81819f02007-05-06 14:49:36 -0700557 start++;
558 bytes--;
559 }
Christoph Lameter24922682007-07-17 04:03:18 -0700560 return NULL;
561}
562
563static void restore_bytes(struct kmem_cache *s, char *message, u8 data,
564 void *from, void *to)
565{
566 slab_fix(s, "Restoring 0x%p-0x%p=0x%x\n", from, to - 1, data);
567 memset(from, data, to - from);
568}
569
570static int check_bytes_and_report(struct kmem_cache *s, struct page *page,
571 u8 *object, char *what,
Pekka Enberg06428782008-01-07 23:20:27 -0800572 u8 *start, unsigned int value, unsigned int bytes)
Christoph Lameter24922682007-07-17 04:03:18 -0700573{
574 u8 *fault;
575 u8 *end;
576
577 fault = check_bytes(start, value, bytes);
578 if (!fault)
579 return 1;
580
581 end = start + bytes;
582 while (end > fault && end[-1] == value)
583 end--;
584
585 slab_bug(s, "%s overwritten", what);
586 printk(KERN_ERR "INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n",
587 fault, end - 1, fault[0], value);
588 print_trailer(s, page, object);
589
590 restore_bytes(s, what, value, fault, end);
591 return 0;
Christoph Lameter81819f02007-05-06 14:49:36 -0700592}
593
Christoph Lameter81819f02007-05-06 14:49:36 -0700594/*
595 * Object layout:
596 *
597 * object address
598 * Bytes of the object to be managed.
599 * If the freepointer may overlay the object then the free
600 * pointer is the first word of the object.
Christoph Lameter672bba32007-05-09 02:32:39 -0700601 *
Christoph Lameter81819f02007-05-06 14:49:36 -0700602 * Poisoning uses 0x6b (POISON_FREE) and the last byte is
603 * 0xa5 (POISON_END)
604 *
605 * object + s->objsize
606 * Padding to reach word boundary. This is also used for Redzoning.
Christoph Lameter672bba32007-05-09 02:32:39 -0700607 * Padding is extended by another word if Redzoning is enabled and
608 * objsize == inuse.
609 *
Christoph Lameter81819f02007-05-06 14:49:36 -0700610 * We fill with 0xbb (RED_INACTIVE) for inactive objects and with
611 * 0xcc (RED_ACTIVE) for objects in use.
612 *
613 * object + s->inuse
Christoph Lameter672bba32007-05-09 02:32:39 -0700614 * Meta data starts here.
615 *
Christoph Lameter81819f02007-05-06 14:49:36 -0700616 * A. Free pointer (if we cannot overwrite object on free)
617 * B. Tracking data for SLAB_STORE_USER
Christoph Lameter672bba32007-05-09 02:32:39 -0700618 * C. Padding to reach required alignment boundary or at mininum
Christoph Lameter6446faa2008-02-15 23:45:26 -0800619 * one word if debugging is on to be able to detect writes
Christoph Lameter672bba32007-05-09 02:32:39 -0700620 * before the word boundary.
621 *
622 * Padding is done using 0x5a (POISON_INUSE)
Christoph Lameter81819f02007-05-06 14:49:36 -0700623 *
624 * object + s->size
Christoph Lameter672bba32007-05-09 02:32:39 -0700625 * Nothing is used beyond s->size.
Christoph Lameter81819f02007-05-06 14:49:36 -0700626 *
Christoph Lameter672bba32007-05-09 02:32:39 -0700627 * If slabcaches are merged then the objsize and inuse boundaries are mostly
628 * ignored. And therefore no slab options that rely on these boundaries
Christoph Lameter81819f02007-05-06 14:49:36 -0700629 * may be used with merged slabcaches.
630 */
631
Christoph Lameter81819f02007-05-06 14:49:36 -0700632static int check_pad_bytes(struct kmem_cache *s, struct page *page, u8 *p)
633{
634 unsigned long off = s->inuse; /* The end of info */
635
636 if (s->offset)
637 /* Freepointer is placed after the object. */
638 off += sizeof(void *);
639
640 if (s->flags & SLAB_STORE_USER)
641 /* We also have user information there */
642 off += 2 * sizeof(struct track);
643
644 if (s->size == off)
645 return 1;
646
Christoph Lameter24922682007-07-17 04:03:18 -0700647 return check_bytes_and_report(s, page, p, "Object padding",
648 p + off, POISON_INUSE, s->size - off);
Christoph Lameter81819f02007-05-06 14:49:36 -0700649}
650
Christoph Lameter39b26462008-04-14 19:11:30 +0300651/* Check the pad bytes at the end of a slab page */
Christoph Lameter81819f02007-05-06 14:49:36 -0700652static int slab_pad_check(struct kmem_cache *s, struct page *page)
653{
Christoph Lameter24922682007-07-17 04:03:18 -0700654 u8 *start;
655 u8 *fault;
656 u8 *end;
657 int length;
658 int remainder;
Christoph Lameter81819f02007-05-06 14:49:36 -0700659
660 if (!(s->flags & SLAB_POISON))
661 return 1;
662
Christoph Lametera973e9d2008-03-01 13:40:44 -0800663 start = page_address(page);
Christoph Lameter834f3d12008-04-14 19:11:31 +0300664 length = (PAGE_SIZE << compound_order(page));
Christoph Lameter39b26462008-04-14 19:11:30 +0300665 end = start + length;
666 remainder = length % s->size;
Christoph Lameter81819f02007-05-06 14:49:36 -0700667 if (!remainder)
668 return 1;
669
Christoph Lameter39b26462008-04-14 19:11:30 +0300670 fault = check_bytes(end - remainder, POISON_INUSE, remainder);
Christoph Lameter24922682007-07-17 04:03:18 -0700671 if (!fault)
672 return 1;
673 while (end > fault && end[-1] == POISON_INUSE)
674 end--;
675
676 slab_err(s, page, "Padding overwritten. 0x%p-0x%p", fault, end - 1);
Christoph Lameter39b26462008-04-14 19:11:30 +0300677 print_section("Padding", end - remainder, remainder);
Christoph Lameter24922682007-07-17 04:03:18 -0700678
679 restore_bytes(s, "slab padding", POISON_INUSE, start, end);
680 return 0;
Christoph Lameter81819f02007-05-06 14:49:36 -0700681}
682
683static int check_object(struct kmem_cache *s, struct page *page,
684 void *object, int active)
685{
686 u8 *p = object;
687 u8 *endobject = object + s->objsize;
688
689 if (s->flags & SLAB_RED_ZONE) {
690 unsigned int red =
691 active ? SLUB_RED_ACTIVE : SLUB_RED_INACTIVE;
692
Christoph Lameter24922682007-07-17 04:03:18 -0700693 if (!check_bytes_and_report(s, page, object, "Redzone",
694 endobject, red, s->inuse - s->objsize))
Christoph Lameter81819f02007-05-06 14:49:36 -0700695 return 0;
Christoph Lameter81819f02007-05-06 14:49:36 -0700696 } else {
Ingo Molnar3adbefe2008-02-05 17:57:39 -0800697 if ((s->flags & SLAB_POISON) && s->objsize < s->inuse) {
698 check_bytes_and_report(s, page, p, "Alignment padding",
699 endobject, POISON_INUSE, s->inuse - s->objsize);
700 }
Christoph Lameter81819f02007-05-06 14:49:36 -0700701 }
702
703 if (s->flags & SLAB_POISON) {
704 if (!active && (s->flags & __OBJECT_POISON) &&
Christoph Lameter24922682007-07-17 04:03:18 -0700705 (!check_bytes_and_report(s, page, p, "Poison", p,
706 POISON_FREE, s->objsize - 1) ||
707 !check_bytes_and_report(s, page, p, "Poison",
Pekka Enberg06428782008-01-07 23:20:27 -0800708 p + s->objsize - 1, POISON_END, 1)))
Christoph Lameter81819f02007-05-06 14:49:36 -0700709 return 0;
Christoph Lameter81819f02007-05-06 14:49:36 -0700710 /*
711 * check_pad_bytes cleans up on its own.
712 */
713 check_pad_bytes(s, page, p);
714 }
715
716 if (!s->offset && active)
717 /*
718 * Object and freepointer overlap. Cannot check
719 * freepointer while object is allocated.
720 */
721 return 1;
722
723 /* Check free pointer validity */
724 if (!check_valid_pointer(s, page, get_freepointer(s, p))) {
725 object_err(s, page, p, "Freepointer corrupt");
726 /*
727 * No choice but to zap it and thus loose the remainder
728 * of the free objects in this slab. May cause
Christoph Lameter672bba32007-05-09 02:32:39 -0700729 * another error because the object count is now wrong.
Christoph Lameter81819f02007-05-06 14:49:36 -0700730 */
Christoph Lametera973e9d2008-03-01 13:40:44 -0800731 set_freepointer(s, p, NULL);
Christoph Lameter81819f02007-05-06 14:49:36 -0700732 return 0;
733 }
734 return 1;
735}
736
737static int check_slab(struct kmem_cache *s, struct page *page)
738{
Christoph Lameter39b26462008-04-14 19:11:30 +0300739 int maxobj;
740
Christoph Lameter81819f02007-05-06 14:49:36 -0700741 VM_BUG_ON(!irqs_disabled());
742
743 if (!PageSlab(page)) {
Christoph Lameter24922682007-07-17 04:03:18 -0700744 slab_err(s, page, "Not a valid slab page");
Christoph Lameter81819f02007-05-06 14:49:36 -0700745 return 0;
746 }
Christoph Lameter39b26462008-04-14 19:11:30 +0300747
748 maxobj = (PAGE_SIZE << compound_order(page)) / s->size;
749 if (page->objects > maxobj) {
750 slab_err(s, page, "objects %u > max %u",
751 s->name, page->objects, maxobj);
752 return 0;
753 }
754 if (page->inuse > page->objects) {
Christoph Lameter24922682007-07-17 04:03:18 -0700755 slab_err(s, page, "inuse %u > max %u",
Christoph Lameter39b26462008-04-14 19:11:30 +0300756 s->name, page->inuse, page->objects);
Christoph Lameter81819f02007-05-06 14:49:36 -0700757 return 0;
758 }
759 /* Slab_pad_check fixes things up after itself */
760 slab_pad_check(s, page);
761 return 1;
762}
763
764/*
Christoph Lameter672bba32007-05-09 02:32:39 -0700765 * Determine if a certain object on a page is on the freelist. Must hold the
766 * slab lock to guarantee that the chains are in a consistent state.
Christoph Lameter81819f02007-05-06 14:49:36 -0700767 */
768static int on_freelist(struct kmem_cache *s, struct page *page, void *search)
769{
770 int nr = 0;
771 void *fp = page->freelist;
772 void *object = NULL;
Christoph Lameter224a88b2008-04-14 19:11:31 +0300773 unsigned long max_objects;
Christoph Lameter81819f02007-05-06 14:49:36 -0700774
Christoph Lameter39b26462008-04-14 19:11:30 +0300775 while (fp && nr <= page->objects) {
Christoph Lameter81819f02007-05-06 14:49:36 -0700776 if (fp == search)
777 return 1;
778 if (!check_valid_pointer(s, page, fp)) {
779 if (object) {
780 object_err(s, page, object,
781 "Freechain corrupt");
Christoph Lametera973e9d2008-03-01 13:40:44 -0800782 set_freepointer(s, object, NULL);
Christoph Lameter81819f02007-05-06 14:49:36 -0700783 break;
784 } else {
Christoph Lameter24922682007-07-17 04:03:18 -0700785 slab_err(s, page, "Freepointer corrupt");
Christoph Lametera973e9d2008-03-01 13:40:44 -0800786 page->freelist = NULL;
Christoph Lameter39b26462008-04-14 19:11:30 +0300787 page->inuse = page->objects;
Christoph Lameter24922682007-07-17 04:03:18 -0700788 slab_fix(s, "Freelist cleared");
Christoph Lameter81819f02007-05-06 14:49:36 -0700789 return 0;
790 }
791 break;
792 }
793 object = fp;
794 fp = get_freepointer(s, object);
795 nr++;
796 }
797
Christoph Lameter224a88b2008-04-14 19:11:31 +0300798 max_objects = (PAGE_SIZE << compound_order(page)) / s->size;
799 if (max_objects > 65535)
800 max_objects = 65535;
801
802 if (page->objects != max_objects) {
803 slab_err(s, page, "Wrong number of objects. Found %d but "
804 "should be %d", page->objects, max_objects);
805 page->objects = max_objects;
806 slab_fix(s, "Number of objects adjusted.");
807 }
Christoph Lameter39b26462008-04-14 19:11:30 +0300808 if (page->inuse != page->objects - nr) {
Christoph Lameter70d71222007-05-06 14:49:47 -0700809 slab_err(s, page, "Wrong object count. Counter is %d but "
Christoph Lameter39b26462008-04-14 19:11:30 +0300810 "counted were %d", page->inuse, page->objects - nr);
811 page->inuse = page->objects - nr;
Christoph Lameter24922682007-07-17 04:03:18 -0700812 slab_fix(s, "Object count adjusted.");
Christoph Lameter81819f02007-05-06 14:49:36 -0700813 }
814 return search == NULL;
815}
816
Christoph Lameter0121c6192008-04-29 16:11:12 -0700817static void trace(struct kmem_cache *s, struct page *page, void *object,
818 int alloc)
Christoph Lameter3ec09742007-05-16 22:11:00 -0700819{
820 if (s->flags & SLAB_TRACE) {
821 printk(KERN_INFO "TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
822 s->name,
823 alloc ? "alloc" : "free",
824 object, page->inuse,
825 page->freelist);
826
827 if (!alloc)
828 print_section("Object", (void *)object, s->objsize);
829
830 dump_stack();
831 }
832}
833
Christoph Lameter643b1132007-05-06 14:49:42 -0700834/*
Christoph Lameter672bba32007-05-09 02:32:39 -0700835 * Tracking of fully allocated slabs for debugging purposes.
Christoph Lameter643b1132007-05-06 14:49:42 -0700836 */
Christoph Lametere95eed52007-05-06 14:49:44 -0700837static void add_full(struct kmem_cache_node *n, struct page *page)
Christoph Lameter643b1132007-05-06 14:49:42 -0700838{
Christoph Lameter643b1132007-05-06 14:49:42 -0700839 spin_lock(&n->list_lock);
840 list_add(&page->lru, &n->full);
841 spin_unlock(&n->list_lock);
842}
843
844static void remove_full(struct kmem_cache *s, struct page *page)
845{
846 struct kmem_cache_node *n;
847
848 if (!(s->flags & SLAB_STORE_USER))
849 return;
850
851 n = get_node(s, page_to_nid(page));
852
853 spin_lock(&n->list_lock);
854 list_del(&page->lru);
855 spin_unlock(&n->list_lock);
856}
857
Christoph Lameter0f389ec2008-04-14 18:53:02 +0300858/* Tracking of the number of slabs for debugging purposes */
859static inline unsigned long slabs_node(struct kmem_cache *s, int node)
860{
861 struct kmem_cache_node *n = get_node(s, node);
862
863 return atomic_long_read(&n->nr_slabs);
864}
865
Christoph Lameter205ab992008-04-14 19:11:40 +0300866static inline void inc_slabs_node(struct kmem_cache *s, int node, int objects)
Christoph Lameter0f389ec2008-04-14 18:53:02 +0300867{
868 struct kmem_cache_node *n = get_node(s, node);
869
870 /*
871 * May be called early in order to allocate a slab for the
872 * kmem_cache_node structure. Solve the chicken-egg
873 * dilemma by deferring the increment of the count during
874 * bootstrap (see early_kmem_cache_node_alloc).
875 */
Christoph Lameter205ab992008-04-14 19:11:40 +0300876 if (!NUMA_BUILD || n) {
Christoph Lameter0f389ec2008-04-14 18:53:02 +0300877 atomic_long_inc(&n->nr_slabs);
Christoph Lameter205ab992008-04-14 19:11:40 +0300878 atomic_long_add(objects, &n->total_objects);
879 }
Christoph Lameter0f389ec2008-04-14 18:53:02 +0300880}
Christoph Lameter205ab992008-04-14 19:11:40 +0300881static inline void dec_slabs_node(struct kmem_cache *s, int node, int objects)
Christoph Lameter0f389ec2008-04-14 18:53:02 +0300882{
883 struct kmem_cache_node *n = get_node(s, node);
884
885 atomic_long_dec(&n->nr_slabs);
Christoph Lameter205ab992008-04-14 19:11:40 +0300886 atomic_long_sub(objects, &n->total_objects);
Christoph Lameter0f389ec2008-04-14 18:53:02 +0300887}
888
889/* Object debug checks for alloc/free paths */
Christoph Lameter3ec09742007-05-16 22:11:00 -0700890static void setup_object_debug(struct kmem_cache *s, struct page *page,
891 void *object)
892{
893 if (!(s->flags & (SLAB_STORE_USER|SLAB_RED_ZONE|__OBJECT_POISON)))
894 return;
895
896 init_object(s, object, 0);
897 init_tracking(s, object);
898}
899
900static int alloc_debug_processing(struct kmem_cache *s, struct page *page,
901 void *object, void *addr)
Christoph Lameter81819f02007-05-06 14:49:36 -0700902{
903 if (!check_slab(s, page))
904 goto bad;
905
Christoph Lameterd692ef62008-02-15 23:45:24 -0800906 if (!on_freelist(s, page, object)) {
Christoph Lameter24922682007-07-17 04:03:18 -0700907 object_err(s, page, object, "Object already allocated");
Christoph Lameter70d71222007-05-06 14:49:47 -0700908 goto bad;
Christoph Lameter81819f02007-05-06 14:49:36 -0700909 }
910
911 if (!check_valid_pointer(s, page, object)) {
912 object_err(s, page, object, "Freelist Pointer check fails");
Christoph Lameter70d71222007-05-06 14:49:47 -0700913 goto bad;
Christoph Lameter81819f02007-05-06 14:49:36 -0700914 }
915
Christoph Lameterd692ef62008-02-15 23:45:24 -0800916 if (!check_object(s, page, object, 0))
Christoph Lameter81819f02007-05-06 14:49:36 -0700917 goto bad;
Christoph Lameter81819f02007-05-06 14:49:36 -0700918
Christoph Lameter3ec09742007-05-16 22:11:00 -0700919 /* Success perform special debug activities for allocs */
920 if (s->flags & SLAB_STORE_USER)
921 set_track(s, object, TRACK_ALLOC, addr);
922 trace(s, page, object, 1);
923 init_object(s, object, 1);
Christoph Lameter81819f02007-05-06 14:49:36 -0700924 return 1;
Christoph Lameter3ec09742007-05-16 22:11:00 -0700925
Christoph Lameter81819f02007-05-06 14:49:36 -0700926bad:
927 if (PageSlab(page)) {
928 /*
929 * If this is a slab page then lets do the best we can
930 * to avoid issues in the future. Marking all objects
Christoph Lameter672bba32007-05-09 02:32:39 -0700931 * as used avoids touching the remaining objects.
Christoph Lameter81819f02007-05-06 14:49:36 -0700932 */
Christoph Lameter24922682007-07-17 04:03:18 -0700933 slab_fix(s, "Marking all objects used");
Christoph Lameter39b26462008-04-14 19:11:30 +0300934 page->inuse = page->objects;
Christoph Lametera973e9d2008-03-01 13:40:44 -0800935 page->freelist = NULL;
Christoph Lameter81819f02007-05-06 14:49:36 -0700936 }
937 return 0;
938}
939
Christoph Lameter3ec09742007-05-16 22:11:00 -0700940static int free_debug_processing(struct kmem_cache *s, struct page *page,
941 void *object, void *addr)
Christoph Lameter81819f02007-05-06 14:49:36 -0700942{
943 if (!check_slab(s, page))
944 goto fail;
945
946 if (!check_valid_pointer(s, page, object)) {
Christoph Lameter70d71222007-05-06 14:49:47 -0700947 slab_err(s, page, "Invalid object pointer 0x%p", object);
Christoph Lameter81819f02007-05-06 14:49:36 -0700948 goto fail;
949 }
950
951 if (on_freelist(s, page, object)) {
Christoph Lameter24922682007-07-17 04:03:18 -0700952 object_err(s, page, object, "Object already free");
Christoph Lameter81819f02007-05-06 14:49:36 -0700953 goto fail;
954 }
955
956 if (!check_object(s, page, object, 1))
957 return 0;
958
959 if (unlikely(s != page->slab)) {
Ingo Molnar3adbefe2008-02-05 17:57:39 -0800960 if (!PageSlab(page)) {
Christoph Lameter70d71222007-05-06 14:49:47 -0700961 slab_err(s, page, "Attempt to free object(0x%p) "
962 "outside of slab", object);
Ingo Molnar3adbefe2008-02-05 17:57:39 -0800963 } else if (!page->slab) {
Christoph Lameter81819f02007-05-06 14:49:36 -0700964 printk(KERN_ERR
Christoph Lameter70d71222007-05-06 14:49:47 -0700965 "SLUB <none>: no slab for object 0x%p.\n",
Christoph Lameter81819f02007-05-06 14:49:36 -0700966 object);
Christoph Lameter70d71222007-05-06 14:49:47 -0700967 dump_stack();
Pekka Enberg06428782008-01-07 23:20:27 -0800968 } else
Christoph Lameter24922682007-07-17 04:03:18 -0700969 object_err(s, page, object,
970 "page slab pointer corrupt.");
Christoph Lameter81819f02007-05-06 14:49:36 -0700971 goto fail;
972 }
Christoph Lameter3ec09742007-05-16 22:11:00 -0700973
974 /* Special debug activities for freeing objects */
Christoph Lametera973e9d2008-03-01 13:40:44 -0800975 if (!SlabFrozen(page) && !page->freelist)
Christoph Lameter3ec09742007-05-16 22:11:00 -0700976 remove_full(s, page);
977 if (s->flags & SLAB_STORE_USER)
978 set_track(s, object, TRACK_FREE, addr);
979 trace(s, page, object, 0);
980 init_object(s, object, 0);
Christoph Lameter81819f02007-05-06 14:49:36 -0700981 return 1;
Christoph Lameter3ec09742007-05-16 22:11:00 -0700982
Christoph Lameter81819f02007-05-06 14:49:36 -0700983fail:
Christoph Lameter24922682007-07-17 04:03:18 -0700984 slab_fix(s, "Object at 0x%p not freed", object);
Christoph Lameter81819f02007-05-06 14:49:36 -0700985 return 0;
986}
987
Christoph Lameter41ecc552007-05-09 02:32:44 -0700988static int __init setup_slub_debug(char *str)
989{
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700990 slub_debug = DEBUG_DEFAULT_FLAGS;
991 if (*str++ != '=' || !*str)
992 /*
993 * No options specified. Switch on full debugging.
994 */
995 goto out;
Christoph Lameter41ecc552007-05-09 02:32:44 -0700996
997 if (*str == ',')
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700998 /*
999 * No options but restriction on slabs. This means full
1000 * debugging for slabs matching a pattern.
1001 */
1002 goto check_slabs;
1003
1004 slub_debug = 0;
1005 if (*str == '-')
1006 /*
1007 * Switch off all debugging measures.
1008 */
1009 goto out;
1010
1011 /*
1012 * Determine which debug features should be switched on
1013 */
Pekka Enberg06428782008-01-07 23:20:27 -08001014 for (; *str && *str != ','; str++) {
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001015 switch (tolower(*str)) {
1016 case 'f':
1017 slub_debug |= SLAB_DEBUG_FREE;
1018 break;
1019 case 'z':
1020 slub_debug |= SLAB_RED_ZONE;
1021 break;
1022 case 'p':
1023 slub_debug |= SLAB_POISON;
1024 break;
1025 case 'u':
1026 slub_debug |= SLAB_STORE_USER;
1027 break;
1028 case 't':
1029 slub_debug |= SLAB_TRACE;
1030 break;
1031 default:
1032 printk(KERN_ERR "slub_debug option '%c' "
Pekka Enberg06428782008-01-07 23:20:27 -08001033 "unknown. skipped\n", *str);
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001034 }
1035 }
1036
1037check_slabs:
1038 if (*str == ',')
Christoph Lameter41ecc552007-05-09 02:32:44 -07001039 slub_debug_slabs = str + 1;
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001040out:
Christoph Lameter41ecc552007-05-09 02:32:44 -07001041 return 1;
1042}
1043
1044__setup("slub_debug", setup_slub_debug);
1045
Christoph Lameterba0268a2007-09-11 15:24:11 -07001046static unsigned long kmem_cache_flags(unsigned long objsize,
1047 unsigned long flags, const char *name,
Christoph Lameter4ba9b9d2007-10-16 23:25:51 -07001048 void (*ctor)(struct kmem_cache *, void *))
Christoph Lameter41ecc552007-05-09 02:32:44 -07001049{
1050 /*
Christoph Lametere1533622008-02-15 23:45:24 -08001051 * Enable debugging if selected on the kernel commandline.
Christoph Lameter41ecc552007-05-09 02:32:44 -07001052 */
Christoph Lametere1533622008-02-15 23:45:24 -08001053 if (slub_debug && (!slub_debug_slabs ||
1054 strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs)) == 0))
1055 flags |= slub_debug;
Christoph Lameterba0268a2007-09-11 15:24:11 -07001056
1057 return flags;
Christoph Lameter41ecc552007-05-09 02:32:44 -07001058}
1059#else
Christoph Lameter3ec09742007-05-16 22:11:00 -07001060static inline void setup_object_debug(struct kmem_cache *s,
1061 struct page *page, void *object) {}
Christoph Lameter41ecc552007-05-09 02:32:44 -07001062
Christoph Lameter3ec09742007-05-16 22:11:00 -07001063static inline int alloc_debug_processing(struct kmem_cache *s,
1064 struct page *page, void *object, void *addr) { return 0; }
Christoph Lameter41ecc552007-05-09 02:32:44 -07001065
Christoph Lameter3ec09742007-05-16 22:11:00 -07001066static inline int free_debug_processing(struct kmem_cache *s,
1067 struct page *page, void *object, void *addr) { return 0; }
Christoph Lameter41ecc552007-05-09 02:32:44 -07001068
Christoph Lameter41ecc552007-05-09 02:32:44 -07001069static inline int slab_pad_check(struct kmem_cache *s, struct page *page)
1070 { return 1; }
1071static inline int check_object(struct kmem_cache *s, struct page *page,
1072 void *object, int active) { return 1; }
Christoph Lameter3ec09742007-05-16 22:11:00 -07001073static inline void add_full(struct kmem_cache_node *n, struct page *page) {}
Christoph Lameterba0268a2007-09-11 15:24:11 -07001074static inline unsigned long kmem_cache_flags(unsigned long objsize,
1075 unsigned long flags, const char *name,
Christoph Lameter4ba9b9d2007-10-16 23:25:51 -07001076 void (*ctor)(struct kmem_cache *, void *))
Christoph Lameterba0268a2007-09-11 15:24:11 -07001077{
1078 return flags;
1079}
Christoph Lameter41ecc552007-05-09 02:32:44 -07001080#define slub_debug 0
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001081
1082static inline unsigned long slabs_node(struct kmem_cache *s, int node)
1083 { return 0; }
Christoph Lameter205ab992008-04-14 19:11:40 +03001084static inline void inc_slabs_node(struct kmem_cache *s, int node,
1085 int objects) {}
1086static inline void dec_slabs_node(struct kmem_cache *s, int node,
1087 int objects) {}
Christoph Lameter41ecc552007-05-09 02:32:44 -07001088#endif
Christoph Lameter205ab992008-04-14 19:11:40 +03001089
Christoph Lameter81819f02007-05-06 14:49:36 -07001090/*
1091 * Slab allocation and freeing
1092 */
Christoph Lameter65c33762008-04-14 19:11:40 +03001093static inline struct page *alloc_slab_page(gfp_t flags, int node,
1094 struct kmem_cache_order_objects oo)
1095{
1096 int order = oo_order(oo);
1097
1098 if (node == -1)
1099 return alloc_pages(flags, order);
1100 else
1101 return alloc_pages_node(node, flags, order);
1102}
1103
Christoph Lameter81819f02007-05-06 14:49:36 -07001104static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
1105{
Pekka Enberg06428782008-01-07 23:20:27 -08001106 struct page *page;
Christoph Lameter834f3d12008-04-14 19:11:31 +03001107 struct kmem_cache_order_objects oo = s->oo;
Christoph Lameter81819f02007-05-06 14:49:36 -07001108
Christoph Lameterb7a49f02008-02-14 14:21:32 -08001109 flags |= s->allocflags;
Mel Gormane12ba742007-10-16 01:25:52 -07001110
Christoph Lameter65c33762008-04-14 19:11:40 +03001111 page = alloc_slab_page(flags | __GFP_NOWARN | __GFP_NORETRY, node,
1112 oo);
1113 if (unlikely(!page)) {
1114 oo = s->min;
1115 /*
1116 * Allocation may have failed due to fragmentation.
1117 * Try a lower order alloc if possible
1118 */
1119 page = alloc_slab_page(flags, node, oo);
1120 if (!page)
1121 return NULL;
Christoph Lameter81819f02007-05-06 14:49:36 -07001122
Christoph Lameter65c33762008-04-14 19:11:40 +03001123 stat(get_cpu_slab(s, raw_smp_processor_id()), ORDER_FALLBACK);
1124 }
Christoph Lameter834f3d12008-04-14 19:11:31 +03001125 page->objects = oo_objects(oo);
Christoph Lameter81819f02007-05-06 14:49:36 -07001126 mod_zone_page_state(page_zone(page),
1127 (s->flags & SLAB_RECLAIM_ACCOUNT) ?
1128 NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
Christoph Lameter65c33762008-04-14 19:11:40 +03001129 1 << oo_order(oo));
Christoph Lameter81819f02007-05-06 14:49:36 -07001130
1131 return page;
1132}
1133
1134static void setup_object(struct kmem_cache *s, struct page *page,
1135 void *object)
1136{
Christoph Lameter3ec09742007-05-16 22:11:00 -07001137 setup_object_debug(s, page, object);
Christoph Lameter4f104932007-05-06 14:50:17 -07001138 if (unlikely(s->ctor))
Christoph Lameter4ba9b9d2007-10-16 23:25:51 -07001139 s->ctor(s, object);
Christoph Lameter81819f02007-05-06 14:49:36 -07001140}
1141
1142static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
1143{
1144 struct page *page;
Christoph Lameter81819f02007-05-06 14:49:36 -07001145 void *start;
Christoph Lameter81819f02007-05-06 14:49:36 -07001146 void *last;
1147 void *p;
1148
Christoph Lameter6cb06222007-10-16 01:25:41 -07001149 BUG_ON(flags & GFP_SLAB_BUG_MASK);
Christoph Lameter81819f02007-05-06 14:49:36 -07001150
Christoph Lameter6cb06222007-10-16 01:25:41 -07001151 page = allocate_slab(s,
1152 flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node);
Christoph Lameter81819f02007-05-06 14:49:36 -07001153 if (!page)
1154 goto out;
1155
Christoph Lameter205ab992008-04-14 19:11:40 +03001156 inc_slabs_node(s, page_to_nid(page), page->objects);
Christoph Lameter81819f02007-05-06 14:49:36 -07001157 page->slab = s;
1158 page->flags |= 1 << PG_slab;
1159 if (s->flags & (SLAB_DEBUG_FREE | SLAB_RED_ZONE | SLAB_POISON |
1160 SLAB_STORE_USER | SLAB_TRACE))
Christoph Lameter35e5d7e2007-05-09 02:32:42 -07001161 SetSlabDebug(page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001162
1163 start = page_address(page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001164
1165 if (unlikely(s->flags & SLAB_POISON))
Christoph Lameter834f3d12008-04-14 19:11:31 +03001166 memset(start, POISON_INUSE, PAGE_SIZE << compound_order(page));
Christoph Lameter81819f02007-05-06 14:49:36 -07001167
1168 last = start;
Christoph Lameter224a88b2008-04-14 19:11:31 +03001169 for_each_object(p, s, start, page->objects) {
Christoph Lameter81819f02007-05-06 14:49:36 -07001170 setup_object(s, page, last);
1171 set_freepointer(s, last, p);
1172 last = p;
1173 }
1174 setup_object(s, page, last);
Christoph Lametera973e9d2008-03-01 13:40:44 -08001175 set_freepointer(s, last, NULL);
Christoph Lameter81819f02007-05-06 14:49:36 -07001176
1177 page->freelist = start;
1178 page->inuse = 0;
1179out:
Christoph Lameter81819f02007-05-06 14:49:36 -07001180 return page;
1181}
1182
1183static void __free_slab(struct kmem_cache *s, struct page *page)
1184{
Christoph Lameter834f3d12008-04-14 19:11:31 +03001185 int order = compound_order(page);
1186 int pages = 1 << order;
Christoph Lameter81819f02007-05-06 14:49:36 -07001187
Christoph Lameterc59def9f2007-05-16 22:10:50 -07001188 if (unlikely(SlabDebug(page))) {
Christoph Lameter81819f02007-05-06 14:49:36 -07001189 void *p;
1190
1191 slab_pad_check(s, page);
Christoph Lameter224a88b2008-04-14 19:11:31 +03001192 for_each_object(p, s, page_address(page),
1193 page->objects)
Christoph Lameter81819f02007-05-06 14:49:36 -07001194 check_object(s, page, p, 0);
Peter Zijlstra2208b762007-07-26 20:54:34 +02001195 ClearSlabDebug(page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001196 }
1197
1198 mod_zone_page_state(page_zone(page),
1199 (s->flags & SLAB_RECLAIM_ACCOUNT) ?
1200 NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
Pekka Enberg06428782008-01-07 23:20:27 -08001201 -pages);
Christoph Lameter81819f02007-05-06 14:49:36 -07001202
Christoph Lameter49bd5222008-04-14 18:52:18 +03001203 __ClearPageSlab(page);
1204 reset_page_mapcount(page);
Christoph Lameter834f3d12008-04-14 19:11:31 +03001205 __free_pages(page, order);
Christoph Lameter81819f02007-05-06 14:49:36 -07001206}
1207
1208static void rcu_free_slab(struct rcu_head *h)
1209{
1210 struct page *page;
1211
1212 page = container_of((struct list_head *)h, struct page, lru);
1213 __free_slab(page->slab, page);
1214}
1215
1216static void free_slab(struct kmem_cache *s, struct page *page)
1217{
1218 if (unlikely(s->flags & SLAB_DESTROY_BY_RCU)) {
1219 /*
1220 * RCU free overloads the RCU head over the LRU
1221 */
1222 struct rcu_head *head = (void *)&page->lru;
1223
1224 call_rcu(head, rcu_free_slab);
1225 } else
1226 __free_slab(s, page);
1227}
1228
1229static void discard_slab(struct kmem_cache *s, struct page *page)
1230{
Christoph Lameter205ab992008-04-14 19:11:40 +03001231 dec_slabs_node(s, page_to_nid(page), page->objects);
Christoph Lameter81819f02007-05-06 14:49:36 -07001232 free_slab(s, page);
1233}
1234
1235/*
1236 * Per slab locking using the pagelock
1237 */
1238static __always_inline void slab_lock(struct page *page)
1239{
1240 bit_spin_lock(PG_locked, &page->flags);
1241}
1242
1243static __always_inline void slab_unlock(struct page *page)
1244{
Nick Piggina76d3542008-01-07 23:20:27 -08001245 __bit_spin_unlock(PG_locked, &page->flags);
Christoph Lameter81819f02007-05-06 14:49:36 -07001246}
1247
1248static __always_inline int slab_trylock(struct page *page)
1249{
1250 int rc = 1;
1251
1252 rc = bit_spin_trylock(PG_locked, &page->flags);
1253 return rc;
1254}
1255
1256/*
1257 * Management of partially allocated slabs
1258 */
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001259static void add_partial(struct kmem_cache_node *n,
1260 struct page *page, int tail)
Christoph Lameter81819f02007-05-06 14:49:36 -07001261{
Christoph Lametere95eed52007-05-06 14:49:44 -07001262 spin_lock(&n->list_lock);
1263 n->nr_partial++;
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001264 if (tail)
1265 list_add_tail(&page->lru, &n->partial);
1266 else
1267 list_add(&page->lru, &n->partial);
Christoph Lameter81819f02007-05-06 14:49:36 -07001268 spin_unlock(&n->list_lock);
1269}
1270
Christoph Lameter0121c6192008-04-29 16:11:12 -07001271static void remove_partial(struct kmem_cache *s, struct page *page)
Christoph Lameter81819f02007-05-06 14:49:36 -07001272{
1273 struct kmem_cache_node *n = get_node(s, page_to_nid(page));
1274
1275 spin_lock(&n->list_lock);
1276 list_del(&page->lru);
1277 n->nr_partial--;
1278 spin_unlock(&n->list_lock);
1279}
1280
1281/*
Christoph Lameter672bba32007-05-09 02:32:39 -07001282 * Lock slab and remove from the partial list.
Christoph Lameter81819f02007-05-06 14:49:36 -07001283 *
Christoph Lameter672bba32007-05-09 02:32:39 -07001284 * Must hold list_lock.
Christoph Lameter81819f02007-05-06 14:49:36 -07001285 */
Christoph Lameter0121c6192008-04-29 16:11:12 -07001286static inline int lock_and_freeze_slab(struct kmem_cache_node *n,
1287 struct page *page)
Christoph Lameter81819f02007-05-06 14:49:36 -07001288{
1289 if (slab_trylock(page)) {
1290 list_del(&page->lru);
1291 n->nr_partial--;
Christoph Lameter4b6f0752007-05-16 22:10:53 -07001292 SetSlabFrozen(page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001293 return 1;
1294 }
1295 return 0;
1296}
1297
1298/*
Christoph Lameter672bba32007-05-09 02:32:39 -07001299 * Try to allocate a partial slab from a specific node.
Christoph Lameter81819f02007-05-06 14:49:36 -07001300 */
1301static struct page *get_partial_node(struct kmem_cache_node *n)
1302{
1303 struct page *page;
1304
1305 /*
1306 * Racy check. If we mistakenly see no partial slabs then we
1307 * just allocate an empty slab. If we mistakenly try to get a
Christoph Lameter672bba32007-05-09 02:32:39 -07001308 * partial slab and there is none available then get_partials()
1309 * will return NULL.
Christoph Lameter81819f02007-05-06 14:49:36 -07001310 */
1311 if (!n || !n->nr_partial)
1312 return NULL;
1313
1314 spin_lock(&n->list_lock);
1315 list_for_each_entry(page, &n->partial, lru)
Christoph Lameter4b6f0752007-05-16 22:10:53 -07001316 if (lock_and_freeze_slab(n, page))
Christoph Lameter81819f02007-05-06 14:49:36 -07001317 goto out;
1318 page = NULL;
1319out:
1320 spin_unlock(&n->list_lock);
1321 return page;
1322}
1323
1324/*
Christoph Lameter672bba32007-05-09 02:32:39 -07001325 * Get a page from somewhere. Search in increasing NUMA distances.
Christoph Lameter81819f02007-05-06 14:49:36 -07001326 */
1327static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags)
1328{
1329#ifdef CONFIG_NUMA
1330 struct zonelist *zonelist;
Mel Gormandd1a2392008-04-28 02:12:17 -07001331 struct zoneref *z;
Mel Gorman54a6eb52008-04-28 02:12:16 -07001332 struct zone *zone;
1333 enum zone_type high_zoneidx = gfp_zone(flags);
Christoph Lameter81819f02007-05-06 14:49:36 -07001334 struct page *page;
1335
1336 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07001337 * The defrag ratio allows a configuration of the tradeoffs between
1338 * inter node defragmentation and node local allocations. A lower
1339 * defrag_ratio increases the tendency to do local allocations
1340 * instead of attempting to obtain partial slabs from other nodes.
Christoph Lameter81819f02007-05-06 14:49:36 -07001341 *
Christoph Lameter672bba32007-05-09 02:32:39 -07001342 * If the defrag_ratio is set to 0 then kmalloc() always
1343 * returns node local objects. If the ratio is higher then kmalloc()
1344 * may return off node objects because partial slabs are obtained
1345 * from other nodes and filled up.
Christoph Lameter81819f02007-05-06 14:49:36 -07001346 *
Christoph Lameter6446faa2008-02-15 23:45:26 -08001347 * If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes
Christoph Lameter672bba32007-05-09 02:32:39 -07001348 * defrag_ratio = 1000) then every (well almost) allocation will
1349 * first attempt to defrag slab caches on other nodes. This means
1350 * scanning over all nodes to look for partial slabs which may be
1351 * expensive if we do it every time we are trying to find a slab
1352 * with available objects.
Christoph Lameter81819f02007-05-06 14:49:36 -07001353 */
Christoph Lameter98246012008-01-07 23:20:26 -08001354 if (!s->remote_node_defrag_ratio ||
1355 get_cycles() % 1024 > s->remote_node_defrag_ratio)
Christoph Lameter81819f02007-05-06 14:49:36 -07001356 return NULL;
1357
Mel Gorman0e884602008-04-28 02:12:14 -07001358 zonelist = node_zonelist(slab_node(current->mempolicy), flags);
Mel Gorman54a6eb52008-04-28 02:12:16 -07001359 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
Christoph Lameter81819f02007-05-06 14:49:36 -07001360 struct kmem_cache_node *n;
1361
Mel Gorman54a6eb52008-04-28 02:12:16 -07001362 n = get_node(s, zone_to_nid(zone));
Christoph Lameter81819f02007-05-06 14:49:36 -07001363
Mel Gorman54a6eb52008-04-28 02:12:16 -07001364 if (n && cpuset_zone_allowed_hardwall(zone, flags) &&
Christoph Lametere95eed52007-05-06 14:49:44 -07001365 n->nr_partial > MIN_PARTIAL) {
Christoph Lameter81819f02007-05-06 14:49:36 -07001366 page = get_partial_node(n);
1367 if (page)
1368 return page;
1369 }
1370 }
1371#endif
1372 return NULL;
1373}
1374
1375/*
1376 * Get a partial page, lock it and return it.
1377 */
1378static struct page *get_partial(struct kmem_cache *s, gfp_t flags, int node)
1379{
1380 struct page *page;
1381 int searchnode = (node == -1) ? numa_node_id() : node;
1382
1383 page = get_partial_node(get_node(s, searchnode));
1384 if (page || (flags & __GFP_THISNODE))
1385 return page;
1386
1387 return get_any_partial(s, flags);
1388}
1389
1390/*
1391 * Move a page back to the lists.
1392 *
1393 * Must be called with the slab lock held.
1394 *
1395 * On exit the slab lock will have been dropped.
1396 */
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001397static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail)
Christoph Lameter81819f02007-05-06 14:49:36 -07001398{
Christoph Lametere95eed52007-05-06 14:49:44 -07001399 struct kmem_cache_node *n = get_node(s, page_to_nid(page));
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001400 struct kmem_cache_cpu *c = get_cpu_slab(s, smp_processor_id());
Christoph Lametere95eed52007-05-06 14:49:44 -07001401
Christoph Lameter4b6f0752007-05-16 22:10:53 -07001402 ClearSlabFrozen(page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001403 if (page->inuse) {
Christoph Lametere95eed52007-05-06 14:49:44 -07001404
Christoph Lametera973e9d2008-03-01 13:40:44 -08001405 if (page->freelist) {
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001406 add_partial(n, page, tail);
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001407 stat(c, tail ? DEACTIVATE_TO_TAIL : DEACTIVATE_TO_HEAD);
1408 } else {
1409 stat(c, DEACTIVATE_FULL);
1410 if (SlabDebug(page) && (s->flags & SLAB_STORE_USER))
1411 add_full(n, page);
1412 }
Christoph Lameter81819f02007-05-06 14:49:36 -07001413 slab_unlock(page);
1414 } else {
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001415 stat(c, DEACTIVATE_EMPTY);
Christoph Lametere95eed52007-05-06 14:49:44 -07001416 if (n->nr_partial < MIN_PARTIAL) {
1417 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07001418 * Adding an empty slab to the partial slabs in order
1419 * to avoid page allocator overhead. This slab needs
1420 * to come after the other slabs with objects in
Christoph Lameter6446faa2008-02-15 23:45:26 -08001421 * so that the others get filled first. That way the
1422 * size of the partial list stays small.
1423 *
Christoph Lameter0121c6192008-04-29 16:11:12 -07001424 * kmem_cache_shrink can reclaim any empty slabs from
1425 * the partial list.
Christoph Lametere95eed52007-05-06 14:49:44 -07001426 */
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001427 add_partial(n, page, 1);
Christoph Lametere95eed52007-05-06 14:49:44 -07001428 slab_unlock(page);
1429 } else {
1430 slab_unlock(page);
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001431 stat(get_cpu_slab(s, raw_smp_processor_id()), FREE_SLAB);
Christoph Lametere95eed52007-05-06 14:49:44 -07001432 discard_slab(s, page);
1433 }
Christoph Lameter81819f02007-05-06 14:49:36 -07001434 }
1435}
1436
1437/*
1438 * Remove the cpu slab
1439 */
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001440static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
Christoph Lameter81819f02007-05-06 14:49:36 -07001441{
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001442 struct page *page = c->page;
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001443 int tail = 1;
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001444
Christoph Lameterb773ad72008-03-04 11:10:17 -08001445 if (page->freelist)
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001446 stat(c, DEACTIVATE_REMOTE_FREES);
Christoph Lameter894b8782007-05-10 03:15:16 -07001447 /*
Christoph Lameter6446faa2008-02-15 23:45:26 -08001448 * Merge cpu freelist into slab freelist. Typically we get here
Christoph Lameter894b8782007-05-10 03:15:16 -07001449 * because both freelists are empty. So this is unlikely
1450 * to occur.
1451 */
Christoph Lametera973e9d2008-03-01 13:40:44 -08001452 while (unlikely(c->freelist)) {
Christoph Lameter894b8782007-05-10 03:15:16 -07001453 void **object;
1454
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001455 tail = 0; /* Hot objects. Put the slab first */
1456
Christoph Lameter894b8782007-05-10 03:15:16 -07001457 /* Retrieve object from cpu_freelist */
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001458 object = c->freelist;
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001459 c->freelist = c->freelist[c->offset];
Christoph Lameter894b8782007-05-10 03:15:16 -07001460
1461 /* And put onto the regular freelist */
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001462 object[c->offset] = page->freelist;
Christoph Lameter894b8782007-05-10 03:15:16 -07001463 page->freelist = object;
1464 page->inuse--;
1465 }
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001466 c->page = NULL;
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001467 unfreeze_slab(s, page, tail);
Christoph Lameter81819f02007-05-06 14:49:36 -07001468}
1469
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001470static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
Christoph Lameter81819f02007-05-06 14:49:36 -07001471{
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001472 stat(c, CPUSLAB_FLUSH);
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001473 slab_lock(c->page);
1474 deactivate_slab(s, c);
Christoph Lameter81819f02007-05-06 14:49:36 -07001475}
1476
1477/*
1478 * Flush cpu slab.
Christoph Lameter6446faa2008-02-15 23:45:26 -08001479 *
Christoph Lameter81819f02007-05-06 14:49:36 -07001480 * Called from IPI handler with interrupts disabled.
1481 */
Christoph Lameter0c710012007-07-17 04:03:24 -07001482static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu)
Christoph Lameter81819f02007-05-06 14:49:36 -07001483{
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001484 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
Christoph Lameter81819f02007-05-06 14:49:36 -07001485
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001486 if (likely(c && c->page))
1487 flush_slab(s, c);
Christoph Lameter81819f02007-05-06 14:49:36 -07001488}
1489
1490static void flush_cpu_slab(void *d)
1491{
1492 struct kmem_cache *s = d;
Christoph Lameter81819f02007-05-06 14:49:36 -07001493
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001494 __flush_cpu_slab(s, smp_processor_id());
Christoph Lameter81819f02007-05-06 14:49:36 -07001495}
1496
1497static void flush_all(struct kmem_cache *s)
1498{
1499#ifdef CONFIG_SMP
1500 on_each_cpu(flush_cpu_slab, s, 1, 1);
1501#else
1502 unsigned long flags;
1503
1504 local_irq_save(flags);
1505 flush_cpu_slab(s);
1506 local_irq_restore(flags);
1507#endif
1508}
1509
1510/*
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001511 * Check if the objects in a per cpu structure fit numa
1512 * locality expectations.
1513 */
1514static inline int node_match(struct kmem_cache_cpu *c, int node)
1515{
1516#ifdef CONFIG_NUMA
1517 if (node != -1 && c->node != node)
1518 return 0;
1519#endif
1520 return 1;
1521}
1522
1523/*
Christoph Lameter894b8782007-05-10 03:15:16 -07001524 * Slow path. The lockless freelist is empty or we need to perform
1525 * debugging duties.
Christoph Lameter81819f02007-05-06 14:49:36 -07001526 *
Christoph Lameter894b8782007-05-10 03:15:16 -07001527 * Interrupts are disabled.
Christoph Lameter81819f02007-05-06 14:49:36 -07001528 *
Christoph Lameter894b8782007-05-10 03:15:16 -07001529 * Processing is still very fast if new objects have been freed to the
1530 * regular freelist. In that case we simply take over the regular freelist
1531 * as the lockless freelist and zap the regular freelist.
Christoph Lameter81819f02007-05-06 14:49:36 -07001532 *
Christoph Lameter894b8782007-05-10 03:15:16 -07001533 * If that is not working then we fall back to the partial lists. We take the
1534 * first element of the freelist as the object to allocate now and move the
1535 * rest of the freelist to the lockless freelist.
1536 *
1537 * And if we were unable to get a new slab from the partial slab lists then
Christoph Lameter6446faa2008-02-15 23:45:26 -08001538 * we need to allocate a new slab. This is the slowest path since it involves
1539 * a call to the page allocator and the setup of a new slab.
Christoph Lameter81819f02007-05-06 14:49:36 -07001540 */
Christoph Lameter894b8782007-05-10 03:15:16 -07001541static void *__slab_alloc(struct kmem_cache *s,
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001542 gfp_t gfpflags, int node, void *addr, struct kmem_cache_cpu *c)
Christoph Lameter81819f02007-05-06 14:49:36 -07001543{
Christoph Lameter81819f02007-05-06 14:49:36 -07001544 void **object;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001545 struct page *new;
Christoph Lameter81819f02007-05-06 14:49:36 -07001546
Linus Torvaldse72e9c22008-03-27 20:56:33 -07001547 /* We handle __GFP_ZERO in the caller */
1548 gfpflags &= ~__GFP_ZERO;
1549
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001550 if (!c->page)
Christoph Lameter81819f02007-05-06 14:49:36 -07001551 goto new_slab;
1552
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001553 slab_lock(c->page);
1554 if (unlikely(!node_match(c, node)))
Christoph Lameter81819f02007-05-06 14:49:36 -07001555 goto another_slab;
Christoph Lameter6446faa2008-02-15 23:45:26 -08001556
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001557 stat(c, ALLOC_REFILL);
Christoph Lameter6446faa2008-02-15 23:45:26 -08001558
Christoph Lameter894b8782007-05-10 03:15:16 -07001559load_freelist:
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001560 object = c->page->freelist;
Christoph Lametera973e9d2008-03-01 13:40:44 -08001561 if (unlikely(!object))
Christoph Lameter81819f02007-05-06 14:49:36 -07001562 goto another_slab;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001563 if (unlikely(SlabDebug(c->page)))
Christoph Lameter81819f02007-05-06 14:49:36 -07001564 goto debug;
1565
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001566 c->freelist = object[c->offset];
Christoph Lameter39b26462008-04-14 19:11:30 +03001567 c->page->inuse = c->page->objects;
Christoph Lametera973e9d2008-03-01 13:40:44 -08001568 c->page->freelist = NULL;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001569 c->node = page_to_nid(c->page);
Christoph Lameter1f842602008-01-07 23:20:30 -08001570unlock_out:
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001571 slab_unlock(c->page);
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001572 stat(c, ALLOC_SLOWPATH);
Christoph Lameter81819f02007-05-06 14:49:36 -07001573 return object;
1574
1575another_slab:
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001576 deactivate_slab(s, c);
Christoph Lameter81819f02007-05-06 14:49:36 -07001577
1578new_slab:
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001579 new = get_partial(s, gfpflags, node);
1580 if (new) {
1581 c->page = new;
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001582 stat(c, ALLOC_FROM_PARTIAL);
Christoph Lameter894b8782007-05-10 03:15:16 -07001583 goto load_freelist;
Christoph Lameter81819f02007-05-06 14:49:36 -07001584 }
1585
Christoph Lameterb811c202007-10-16 23:25:51 -07001586 if (gfpflags & __GFP_WAIT)
1587 local_irq_enable();
1588
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001589 new = new_slab(s, gfpflags, node);
Christoph Lameterb811c202007-10-16 23:25:51 -07001590
1591 if (gfpflags & __GFP_WAIT)
1592 local_irq_disable();
1593
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001594 if (new) {
1595 c = get_cpu_slab(s, smp_processor_id());
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001596 stat(c, ALLOC_SLAB);
Christoph Lameter05aa3452007-11-05 11:31:58 -08001597 if (c->page)
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001598 flush_slab(s, c);
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001599 slab_lock(new);
1600 SetSlabFrozen(new);
1601 c->page = new;
Christoph Lameter4b6f0752007-05-16 22:10:53 -07001602 goto load_freelist;
Christoph Lameter81819f02007-05-06 14:49:36 -07001603 }
Christoph Lameter71c7a062008-02-14 14:28:01 -08001604 return NULL;
Christoph Lameter81819f02007-05-06 14:49:36 -07001605debug:
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001606 if (!alloc_debug_processing(s, c->page, object, addr))
Christoph Lameter81819f02007-05-06 14:49:36 -07001607 goto another_slab;
Christoph Lameter894b8782007-05-10 03:15:16 -07001608
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001609 c->page->inuse++;
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001610 c->page->freelist = object[c->offset];
Christoph Lameteree3c72a2007-10-16 01:26:07 -07001611 c->node = -1;
Christoph Lameter1f842602008-01-07 23:20:30 -08001612 goto unlock_out;
Christoph Lameter894b8782007-05-10 03:15:16 -07001613}
1614
1615/*
1616 * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
1617 * have the fastpath folded into their functions. So no function call
1618 * overhead for requests that can be satisfied on the fastpath.
1619 *
1620 * The fastpath works by first checking if the lockless freelist can be used.
1621 * If not then __slab_alloc is called for slow processing.
1622 *
1623 * Otherwise we can simply pick the next object from the lockless free list.
1624 */
Pekka Enberg06428782008-01-07 23:20:27 -08001625static __always_inline void *slab_alloc(struct kmem_cache *s,
Christoph Lameterce15fea2007-07-17 04:03:28 -07001626 gfp_t gfpflags, int node, void *addr)
Christoph Lameter894b8782007-05-10 03:15:16 -07001627{
Christoph Lameter894b8782007-05-10 03:15:16 -07001628 void **object;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001629 struct kmem_cache_cpu *c;
Christoph Lameter1f842602008-01-07 23:20:30 -08001630 unsigned long flags;
1631
Christoph Lameter894b8782007-05-10 03:15:16 -07001632 local_irq_save(flags);
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001633 c = get_cpu_slab(s, smp_processor_id());
Christoph Lametera973e9d2008-03-01 13:40:44 -08001634 if (unlikely(!c->freelist || !node_match(c, node)))
Christoph Lameter894b8782007-05-10 03:15:16 -07001635
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001636 object = __slab_alloc(s, gfpflags, node, addr, c);
Christoph Lameter894b8782007-05-10 03:15:16 -07001637
1638 else {
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001639 object = c->freelist;
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001640 c->freelist = object[c->offset];
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001641 stat(c, ALLOC_FASTPATH);
Christoph Lameter894b8782007-05-10 03:15:16 -07001642 }
1643 local_irq_restore(flags);
Christoph Lameterd07dbea2007-07-17 04:03:23 -07001644
1645 if (unlikely((gfpflags & __GFP_ZERO) && object))
Christoph Lameter42a9fdb2007-10-16 01:26:09 -07001646 memset(object, 0, c->objsize);
Christoph Lameterd07dbea2007-07-17 04:03:23 -07001647
Christoph Lameter894b8782007-05-10 03:15:16 -07001648 return object;
Christoph Lameter81819f02007-05-06 14:49:36 -07001649}
1650
1651void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags)
1652{
Christoph Lameterce15fea2007-07-17 04:03:28 -07001653 return slab_alloc(s, gfpflags, -1, __builtin_return_address(0));
Christoph Lameter81819f02007-05-06 14:49:36 -07001654}
1655EXPORT_SYMBOL(kmem_cache_alloc);
1656
1657#ifdef CONFIG_NUMA
1658void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, int node)
1659{
Christoph Lameterce15fea2007-07-17 04:03:28 -07001660 return slab_alloc(s, gfpflags, node, __builtin_return_address(0));
Christoph Lameter81819f02007-05-06 14:49:36 -07001661}
1662EXPORT_SYMBOL(kmem_cache_alloc_node);
1663#endif
1664
1665/*
Christoph Lameter894b8782007-05-10 03:15:16 -07001666 * Slow patch handling. This may still be called frequently since objects
1667 * have a longer lifetime than the cpu slabs in most processing loads.
Christoph Lameter81819f02007-05-06 14:49:36 -07001668 *
Christoph Lameter894b8782007-05-10 03:15:16 -07001669 * So we still attempt to reduce cache line usage. Just take the slab
1670 * lock and free the item. If there is no additional partial page
1671 * handling required then we can return immediately.
Christoph Lameter81819f02007-05-06 14:49:36 -07001672 */
Christoph Lameter894b8782007-05-10 03:15:16 -07001673static void __slab_free(struct kmem_cache *s, struct page *page,
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001674 void *x, void *addr, unsigned int offset)
Christoph Lameter81819f02007-05-06 14:49:36 -07001675{
1676 void *prior;
1677 void **object = (void *)x;
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001678 struct kmem_cache_cpu *c;
Christoph Lameter81819f02007-05-06 14:49:36 -07001679
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001680 c = get_cpu_slab(s, raw_smp_processor_id());
1681 stat(c, FREE_SLOWPATH);
Christoph Lameter81819f02007-05-06 14:49:36 -07001682 slab_lock(page);
1683
Christoph Lameter35e5d7e2007-05-09 02:32:42 -07001684 if (unlikely(SlabDebug(page)))
Christoph Lameter81819f02007-05-06 14:49:36 -07001685 goto debug;
Christoph Lameter6446faa2008-02-15 23:45:26 -08001686
Christoph Lameter81819f02007-05-06 14:49:36 -07001687checks_ok:
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001688 prior = object[offset] = page->freelist;
Christoph Lameter81819f02007-05-06 14:49:36 -07001689 page->freelist = object;
1690 page->inuse--;
1691
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001692 if (unlikely(SlabFrozen(page))) {
1693 stat(c, FREE_FROZEN);
Christoph Lameter81819f02007-05-06 14:49:36 -07001694 goto out_unlock;
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001695 }
Christoph Lameter81819f02007-05-06 14:49:36 -07001696
1697 if (unlikely(!page->inuse))
1698 goto slab_empty;
1699
1700 /*
Christoph Lameter6446faa2008-02-15 23:45:26 -08001701 * Objects left in the slab. If it was not on the partial list before
Christoph Lameter81819f02007-05-06 14:49:36 -07001702 * then add it.
1703 */
Christoph Lametera973e9d2008-03-01 13:40:44 -08001704 if (unlikely(!prior)) {
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001705 add_partial(get_node(s, page_to_nid(page)), page, 1);
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001706 stat(c, FREE_ADD_PARTIAL);
1707 }
Christoph Lameter81819f02007-05-06 14:49:36 -07001708
1709out_unlock:
1710 slab_unlock(page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001711 return;
1712
1713slab_empty:
Christoph Lametera973e9d2008-03-01 13:40:44 -08001714 if (prior) {
Christoph Lameter81819f02007-05-06 14:49:36 -07001715 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07001716 * Slab still on the partial list.
Christoph Lameter81819f02007-05-06 14:49:36 -07001717 */
1718 remove_partial(s, page);
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001719 stat(c, FREE_REMOVE_PARTIAL);
1720 }
Christoph Lameter81819f02007-05-06 14:49:36 -07001721 slab_unlock(page);
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001722 stat(c, FREE_SLAB);
Christoph Lameter81819f02007-05-06 14:49:36 -07001723 discard_slab(s, page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001724 return;
1725
1726debug:
Christoph Lameter3ec09742007-05-16 22:11:00 -07001727 if (!free_debug_processing(s, page, x, addr))
Christoph Lameter77c5e2d2007-05-06 14:49:42 -07001728 goto out_unlock;
Christoph Lameter77c5e2d2007-05-06 14:49:42 -07001729 goto checks_ok;
Christoph Lameter81819f02007-05-06 14:49:36 -07001730}
1731
Christoph Lameter894b8782007-05-10 03:15:16 -07001732/*
1733 * Fastpath with forced inlining to produce a kfree and kmem_cache_free that
1734 * can perform fastpath freeing without additional function calls.
1735 *
1736 * The fastpath is only possible if we are freeing to the current cpu slab
1737 * of this processor. This typically the case if we have just allocated
1738 * the item before.
1739 *
1740 * If fastpath is not possible then fall back to __slab_free where we deal
1741 * with all sorts of special processing.
1742 */
Pekka Enberg06428782008-01-07 23:20:27 -08001743static __always_inline void slab_free(struct kmem_cache *s,
Christoph Lameter894b8782007-05-10 03:15:16 -07001744 struct page *page, void *x, void *addr)
1745{
1746 void **object = (void *)x;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001747 struct kmem_cache_cpu *c;
Christoph Lameter1f842602008-01-07 23:20:30 -08001748 unsigned long flags;
1749
Christoph Lameter894b8782007-05-10 03:15:16 -07001750 local_irq_save(flags);
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001751 c = get_cpu_slab(s, smp_processor_id());
Christoph Lameter27d9e4e2008-02-15 23:45:25 -08001752 debug_check_no_locks_freed(object, c->objsize);
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -07001753 if (!(s->flags & SLAB_DEBUG_OBJECTS))
1754 debug_check_no_obj_freed(object, s->objsize);
Christoph Lameteree3c72a2007-10-16 01:26:07 -07001755 if (likely(page == c->page && c->node >= 0)) {
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001756 object[c->offset] = c->freelist;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001757 c->freelist = object;
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08001758 stat(c, FREE_FASTPATH);
Christoph Lameter894b8782007-05-10 03:15:16 -07001759 } else
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001760 __slab_free(s, page, x, addr, c->offset);
Christoph Lameter894b8782007-05-10 03:15:16 -07001761
1762 local_irq_restore(flags);
1763}
1764
Christoph Lameter81819f02007-05-06 14:49:36 -07001765void kmem_cache_free(struct kmem_cache *s, void *x)
1766{
Christoph Lameter77c5e2d2007-05-06 14:49:42 -07001767 struct page *page;
Christoph Lameter81819f02007-05-06 14:49:36 -07001768
Christoph Lameterb49af682007-05-06 14:49:41 -07001769 page = virt_to_head_page(x);
Christoph Lameter81819f02007-05-06 14:49:36 -07001770
Christoph Lameter77c5e2d2007-05-06 14:49:42 -07001771 slab_free(s, page, x, __builtin_return_address(0));
Christoph Lameter81819f02007-05-06 14:49:36 -07001772}
1773EXPORT_SYMBOL(kmem_cache_free);
1774
1775/* Figure out on which slab object the object resides */
1776static struct page *get_object_page(const void *x)
1777{
Christoph Lameterb49af682007-05-06 14:49:41 -07001778 struct page *page = virt_to_head_page(x);
Christoph Lameter81819f02007-05-06 14:49:36 -07001779
1780 if (!PageSlab(page))
1781 return NULL;
1782
1783 return page;
1784}
1785
1786/*
Christoph Lameter672bba32007-05-09 02:32:39 -07001787 * Object placement in a slab is made very easy because we always start at
1788 * offset 0. If we tune the size of the object to the alignment then we can
1789 * get the required alignment by putting one properly sized object after
1790 * another.
Christoph Lameter81819f02007-05-06 14:49:36 -07001791 *
1792 * Notice that the allocation order determines the sizes of the per cpu
1793 * caches. Each processor has always one slab available for allocations.
1794 * Increasing the allocation order reduces the number of times that slabs
Christoph Lameter672bba32007-05-09 02:32:39 -07001795 * must be moved on and off the partial lists and is therefore a factor in
Christoph Lameter81819f02007-05-06 14:49:36 -07001796 * locking overhead.
Christoph Lameter81819f02007-05-06 14:49:36 -07001797 */
1798
1799/*
1800 * Mininum / Maximum order of slab pages. This influences locking overhead
1801 * and slab fragmentation. A higher order reduces the number of partial slabs
1802 * and increases the number of allocations possible without having to
1803 * take the list_lock.
1804 */
1805static int slub_min_order;
Christoph Lameter114e9e82008-04-14 19:11:41 +03001806static int slub_max_order = PAGE_ALLOC_COSTLY_ORDER;
Christoph Lameter9b2cd502008-04-14 19:11:41 +03001807static int slub_min_objects;
Christoph Lameter81819f02007-05-06 14:49:36 -07001808
1809/*
1810 * Merge control. If this is set then no merging of slab caches will occur.
Christoph Lameter672bba32007-05-09 02:32:39 -07001811 * (Could be removed. This was introduced to pacify the merge skeptics.)
Christoph Lameter81819f02007-05-06 14:49:36 -07001812 */
1813static int slub_nomerge;
1814
1815/*
Christoph Lameter81819f02007-05-06 14:49:36 -07001816 * Calculate the order of allocation given an slab object size.
1817 *
Christoph Lameter672bba32007-05-09 02:32:39 -07001818 * The order of allocation has significant impact on performance and other
1819 * system components. Generally order 0 allocations should be preferred since
1820 * order 0 does not cause fragmentation in the page allocator. Larger objects
1821 * be problematic to put into order 0 slabs because there may be too much
Christoph Lameterc124f5b2008-04-14 19:13:29 +03001822 * unused space left. We go to a higher order if more than 1/16th of the slab
Christoph Lameter672bba32007-05-09 02:32:39 -07001823 * would be wasted.
Christoph Lameter81819f02007-05-06 14:49:36 -07001824 *
Christoph Lameter672bba32007-05-09 02:32:39 -07001825 * In order to reach satisfactory performance we must ensure that a minimum
1826 * number of objects is in one slab. Otherwise we may generate too much
1827 * activity on the partial lists which requires taking the list_lock. This is
1828 * less a concern for large slabs though which are rarely used.
Christoph Lameter81819f02007-05-06 14:49:36 -07001829 *
Christoph Lameter672bba32007-05-09 02:32:39 -07001830 * slub_max_order specifies the order where we begin to stop considering the
1831 * number of objects in a slab as critical. If we reach slub_max_order then
1832 * we try to keep the page order as low as possible. So we accept more waste
1833 * of space in favor of a small page order.
1834 *
1835 * Higher order allocations also allow the placement of more objects in a
1836 * slab and thereby reduce object handling overhead. If the user has
1837 * requested a higher mininum order then we start with that one instead of
1838 * the smallest order which will fit the object.
Christoph Lameter81819f02007-05-06 14:49:36 -07001839 */
Christoph Lameter5e6d4442007-05-09 02:32:46 -07001840static inline int slab_order(int size, int min_objects,
1841 int max_order, int fract_leftover)
Christoph Lameter81819f02007-05-06 14:49:36 -07001842{
1843 int order;
1844 int rem;
Christoph Lameter6300ea72007-07-17 04:03:20 -07001845 int min_order = slub_min_order;
Christoph Lameter81819f02007-05-06 14:49:36 -07001846
Christoph Lameter39b26462008-04-14 19:11:30 +03001847 if ((PAGE_SIZE << min_order) / size > 65535)
1848 return get_order(size * 65535) - 1;
1849
Christoph Lameter6300ea72007-07-17 04:03:20 -07001850 for (order = max(min_order,
Christoph Lameter5e6d4442007-05-09 02:32:46 -07001851 fls(min_objects * size - 1) - PAGE_SHIFT);
1852 order <= max_order; order++) {
1853
Christoph Lameter81819f02007-05-06 14:49:36 -07001854 unsigned long slab_size = PAGE_SIZE << order;
1855
Christoph Lameter5e6d4442007-05-09 02:32:46 -07001856 if (slab_size < min_objects * size)
Christoph Lameter81819f02007-05-06 14:49:36 -07001857 continue;
1858
Christoph Lameter81819f02007-05-06 14:49:36 -07001859 rem = slab_size % size;
1860
Christoph Lameter5e6d4442007-05-09 02:32:46 -07001861 if (rem <= slab_size / fract_leftover)
Christoph Lameter81819f02007-05-06 14:49:36 -07001862 break;
1863
1864 }
Christoph Lameter672bba32007-05-09 02:32:39 -07001865
Christoph Lameter81819f02007-05-06 14:49:36 -07001866 return order;
1867}
1868
Christoph Lameter5e6d4442007-05-09 02:32:46 -07001869static inline int calculate_order(int size)
1870{
1871 int order;
1872 int min_objects;
1873 int fraction;
1874
1875 /*
1876 * Attempt to find best configuration for a slab. This
1877 * works by first attempting to generate a layout with
1878 * the best configuration and backing off gradually.
1879 *
1880 * First we reduce the acceptable waste in a slab. Then
1881 * we reduce the minimum objects required in a slab.
1882 */
1883 min_objects = slub_min_objects;
Christoph Lameter9b2cd502008-04-14 19:11:41 +03001884 if (!min_objects)
1885 min_objects = 4 * (fls(nr_cpu_ids) + 1);
Christoph Lameter5e6d4442007-05-09 02:32:46 -07001886 while (min_objects > 1) {
Christoph Lameterc124f5b2008-04-14 19:13:29 +03001887 fraction = 16;
Christoph Lameter5e6d4442007-05-09 02:32:46 -07001888 while (fraction >= 4) {
1889 order = slab_order(size, min_objects,
1890 slub_max_order, fraction);
1891 if (order <= slub_max_order)
1892 return order;
1893 fraction /= 2;
1894 }
1895 min_objects /= 2;
1896 }
1897
1898 /*
1899 * We were unable to place multiple objects in a slab. Now
1900 * lets see if we can place a single object there.
1901 */
1902 order = slab_order(size, 1, slub_max_order, 1);
1903 if (order <= slub_max_order)
1904 return order;
1905
1906 /*
1907 * Doh this slab cannot be placed using slub_max_order.
1908 */
1909 order = slab_order(size, 1, MAX_ORDER, 1);
1910 if (order <= MAX_ORDER)
1911 return order;
1912 return -ENOSYS;
1913}
1914
Christoph Lameter81819f02007-05-06 14:49:36 -07001915/*
Christoph Lameter672bba32007-05-09 02:32:39 -07001916 * Figure out what the alignment of the objects will be.
Christoph Lameter81819f02007-05-06 14:49:36 -07001917 */
1918static unsigned long calculate_alignment(unsigned long flags,
1919 unsigned long align, unsigned long size)
1920{
1921 /*
Christoph Lameter6446faa2008-02-15 23:45:26 -08001922 * If the user wants hardware cache aligned objects then follow that
1923 * suggestion if the object is sufficiently large.
Christoph Lameter81819f02007-05-06 14:49:36 -07001924 *
Christoph Lameter6446faa2008-02-15 23:45:26 -08001925 * The hardware cache alignment cannot override the specified
1926 * alignment though. If that is greater then use it.
Christoph Lameter81819f02007-05-06 14:49:36 -07001927 */
Nick Pigginb6210382008-03-05 14:05:56 -08001928 if (flags & SLAB_HWCACHE_ALIGN) {
1929 unsigned long ralign = cache_line_size();
1930 while (size <= ralign / 2)
1931 ralign /= 2;
1932 align = max(align, ralign);
1933 }
Christoph Lameter81819f02007-05-06 14:49:36 -07001934
1935 if (align < ARCH_SLAB_MINALIGN)
Nick Pigginb6210382008-03-05 14:05:56 -08001936 align = ARCH_SLAB_MINALIGN;
Christoph Lameter81819f02007-05-06 14:49:36 -07001937
1938 return ALIGN(align, sizeof(void *));
1939}
1940
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001941static void init_kmem_cache_cpu(struct kmem_cache *s,
1942 struct kmem_cache_cpu *c)
1943{
1944 c->page = NULL;
Christoph Lametera973e9d2008-03-01 13:40:44 -08001945 c->freelist = NULL;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001946 c->node = 0;
Christoph Lameter42a9fdb2007-10-16 01:26:09 -07001947 c->offset = s->offset / sizeof(void *);
1948 c->objsize = s->objsize;
Pekka Enberg62f75532008-04-14 18:50:44 +03001949#ifdef CONFIG_SLUB_STATS
1950 memset(c->stat, 0, NR_SLUB_STAT_ITEMS * sizeof(unsigned));
1951#endif
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001952}
1953
Christoph Lameter81819f02007-05-06 14:49:36 -07001954static void init_kmem_cache_node(struct kmem_cache_node *n)
1955{
1956 n->nr_partial = 0;
Christoph Lameter81819f02007-05-06 14:49:36 -07001957 spin_lock_init(&n->list_lock);
1958 INIT_LIST_HEAD(&n->partial);
Christoph Lameter8ab13722007-07-17 04:03:32 -07001959#ifdef CONFIG_SLUB_DEBUG
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001960 atomic_long_set(&n->nr_slabs, 0);
Christoph Lameter643b1132007-05-06 14:49:42 -07001961 INIT_LIST_HEAD(&n->full);
Christoph Lameter8ab13722007-07-17 04:03:32 -07001962#endif
Christoph Lameter81819f02007-05-06 14:49:36 -07001963}
1964
Christoph Lameter4c93c3552007-10-16 01:26:08 -07001965#ifdef CONFIG_SMP
1966/*
1967 * Per cpu array for per cpu structures.
1968 *
1969 * The per cpu array places all kmem_cache_cpu structures from one processor
1970 * close together meaning that it becomes possible that multiple per cpu
1971 * structures are contained in one cacheline. This may be particularly
1972 * beneficial for the kmalloc caches.
1973 *
1974 * A desktop system typically has around 60-80 slabs. With 100 here we are
1975 * likely able to get per cpu structures for all caches from the array defined
1976 * here. We must be able to cover all kmalloc caches during bootstrap.
1977 *
1978 * If the per cpu array is exhausted then fall back to kmalloc
1979 * of individual cachelines. No sharing is possible then.
1980 */
1981#define NR_KMEM_CACHE_CPU 100
1982
1983static DEFINE_PER_CPU(struct kmem_cache_cpu,
1984 kmem_cache_cpu)[NR_KMEM_CACHE_CPU];
1985
1986static DEFINE_PER_CPU(struct kmem_cache_cpu *, kmem_cache_cpu_free);
1987static cpumask_t kmem_cach_cpu_free_init_once = CPU_MASK_NONE;
1988
1989static struct kmem_cache_cpu *alloc_kmem_cache_cpu(struct kmem_cache *s,
1990 int cpu, gfp_t flags)
1991{
1992 struct kmem_cache_cpu *c = per_cpu(kmem_cache_cpu_free, cpu);
1993
1994 if (c)
1995 per_cpu(kmem_cache_cpu_free, cpu) =
1996 (void *)c->freelist;
1997 else {
1998 /* Table overflow: So allocate ourselves */
1999 c = kmalloc_node(
2000 ALIGN(sizeof(struct kmem_cache_cpu), cache_line_size()),
2001 flags, cpu_to_node(cpu));
2002 if (!c)
2003 return NULL;
2004 }
2005
2006 init_kmem_cache_cpu(s, c);
2007 return c;
2008}
2009
2010static void free_kmem_cache_cpu(struct kmem_cache_cpu *c, int cpu)
2011{
2012 if (c < per_cpu(kmem_cache_cpu, cpu) ||
2013 c > per_cpu(kmem_cache_cpu, cpu) + NR_KMEM_CACHE_CPU) {
2014 kfree(c);
2015 return;
2016 }
2017 c->freelist = (void *)per_cpu(kmem_cache_cpu_free, cpu);
2018 per_cpu(kmem_cache_cpu_free, cpu) = c;
2019}
2020
2021static void free_kmem_cache_cpus(struct kmem_cache *s)
2022{
2023 int cpu;
2024
2025 for_each_online_cpu(cpu) {
2026 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
2027
2028 if (c) {
2029 s->cpu_slab[cpu] = NULL;
2030 free_kmem_cache_cpu(c, cpu);
2031 }
2032 }
2033}
2034
2035static int alloc_kmem_cache_cpus(struct kmem_cache *s, gfp_t flags)
2036{
2037 int cpu;
2038
2039 for_each_online_cpu(cpu) {
2040 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
2041
2042 if (c)
2043 continue;
2044
2045 c = alloc_kmem_cache_cpu(s, cpu, flags);
2046 if (!c) {
2047 free_kmem_cache_cpus(s);
2048 return 0;
2049 }
2050 s->cpu_slab[cpu] = c;
2051 }
2052 return 1;
2053}
2054
2055/*
2056 * Initialize the per cpu array.
2057 */
2058static void init_alloc_cpu_cpu(int cpu)
2059{
2060 int i;
2061
2062 if (cpu_isset(cpu, kmem_cach_cpu_free_init_once))
2063 return;
2064
2065 for (i = NR_KMEM_CACHE_CPU - 1; i >= 0; i--)
2066 free_kmem_cache_cpu(&per_cpu(kmem_cache_cpu, cpu)[i], cpu);
2067
2068 cpu_set(cpu, kmem_cach_cpu_free_init_once);
2069}
2070
2071static void __init init_alloc_cpu(void)
2072{
2073 int cpu;
2074
2075 for_each_online_cpu(cpu)
2076 init_alloc_cpu_cpu(cpu);
2077 }
2078
2079#else
2080static inline void free_kmem_cache_cpus(struct kmem_cache *s) {}
2081static inline void init_alloc_cpu(void) {}
2082
2083static inline int alloc_kmem_cache_cpus(struct kmem_cache *s, gfp_t flags)
2084{
2085 init_kmem_cache_cpu(s, &s->cpu_slab);
2086 return 1;
2087}
2088#endif
2089
Christoph Lameter81819f02007-05-06 14:49:36 -07002090#ifdef CONFIG_NUMA
2091/*
2092 * No kmalloc_node yet so do it by hand. We know that this is the first
2093 * slab on the node for this slabcache. There are no concurrent accesses
2094 * possible.
2095 *
2096 * Note that this function only works on the kmalloc_node_cache
Christoph Lameter4c93c3552007-10-16 01:26:08 -07002097 * when allocating for the kmalloc_node_cache. This is used for bootstrapping
2098 * memory on a fresh node that has no slab structures yet.
Christoph Lameter81819f02007-05-06 14:49:36 -07002099 */
Adrian Bunk1cd7daa2007-10-16 01:24:18 -07002100static struct kmem_cache_node *early_kmem_cache_node_alloc(gfp_t gfpflags,
2101 int node)
Christoph Lameter81819f02007-05-06 14:49:36 -07002102{
2103 struct page *page;
2104 struct kmem_cache_node *n;
rootba84c732008-01-07 23:20:28 -08002105 unsigned long flags;
Christoph Lameter81819f02007-05-06 14:49:36 -07002106
2107 BUG_ON(kmalloc_caches->size < sizeof(struct kmem_cache_node));
2108
Christoph Lametera2f92ee2007-08-22 14:01:57 -07002109 page = new_slab(kmalloc_caches, gfpflags, node);
Christoph Lameter81819f02007-05-06 14:49:36 -07002110
2111 BUG_ON(!page);
Christoph Lametera2f92ee2007-08-22 14:01:57 -07002112 if (page_to_nid(page) != node) {
2113 printk(KERN_ERR "SLUB: Unable to allocate memory from "
2114 "node %d\n", node);
2115 printk(KERN_ERR "SLUB: Allocating a useless per node structure "
2116 "in order to be able to continue\n");
2117 }
2118
Christoph Lameter81819f02007-05-06 14:49:36 -07002119 n = page->freelist;
2120 BUG_ON(!n);
2121 page->freelist = get_freepointer(kmalloc_caches, n);
2122 page->inuse++;
2123 kmalloc_caches->node[node] = n;
Christoph Lameter8ab13722007-07-17 04:03:32 -07002124#ifdef CONFIG_SLUB_DEBUG
Christoph Lameterd45f39c2007-07-17 04:03:21 -07002125 init_object(kmalloc_caches, n, 1);
2126 init_tracking(kmalloc_caches, n);
Christoph Lameter8ab13722007-07-17 04:03:32 -07002127#endif
Christoph Lameter81819f02007-05-06 14:49:36 -07002128 init_kmem_cache_node(n);
Christoph Lameter205ab992008-04-14 19:11:40 +03002129 inc_slabs_node(kmalloc_caches, node, page->objects);
Christoph Lameter6446faa2008-02-15 23:45:26 -08002130
rootba84c732008-01-07 23:20:28 -08002131 /*
2132 * lockdep requires consistent irq usage for each lock
2133 * so even though there cannot be a race this early in
2134 * the boot sequence, we still disable irqs.
2135 */
2136 local_irq_save(flags);
Christoph Lameter7c2e1322008-01-07 23:20:27 -08002137 add_partial(n, page, 0);
rootba84c732008-01-07 23:20:28 -08002138 local_irq_restore(flags);
Christoph Lameter81819f02007-05-06 14:49:36 -07002139 return n;
2140}
2141
2142static void free_kmem_cache_nodes(struct kmem_cache *s)
2143{
2144 int node;
2145
Christoph Lameterf64dc582007-10-16 01:25:33 -07002146 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002147 struct kmem_cache_node *n = s->node[node];
2148 if (n && n != &s->local_node)
2149 kmem_cache_free(kmalloc_caches, n);
2150 s->node[node] = NULL;
2151 }
2152}
2153
2154static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags)
2155{
2156 int node;
2157 int local_node;
2158
2159 if (slab_state >= UP)
2160 local_node = page_to_nid(virt_to_page(s));
2161 else
2162 local_node = 0;
2163
Christoph Lameterf64dc582007-10-16 01:25:33 -07002164 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002165 struct kmem_cache_node *n;
2166
2167 if (local_node == node)
2168 n = &s->local_node;
2169 else {
2170 if (slab_state == DOWN) {
2171 n = early_kmem_cache_node_alloc(gfpflags,
2172 node);
2173 continue;
2174 }
2175 n = kmem_cache_alloc_node(kmalloc_caches,
2176 gfpflags, node);
2177
2178 if (!n) {
2179 free_kmem_cache_nodes(s);
2180 return 0;
2181 }
2182
2183 }
2184 s->node[node] = n;
2185 init_kmem_cache_node(n);
2186 }
2187 return 1;
2188}
2189#else
2190static void free_kmem_cache_nodes(struct kmem_cache *s)
2191{
2192}
2193
2194static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags)
2195{
2196 init_kmem_cache_node(&s->local_node);
2197 return 1;
2198}
2199#endif
2200
2201/*
2202 * calculate_sizes() determines the order and the distribution of data within
2203 * a slab object.
2204 */
Christoph Lameter06b285d2008-04-14 19:11:41 +03002205static int calculate_sizes(struct kmem_cache *s, int forced_order)
Christoph Lameter81819f02007-05-06 14:49:36 -07002206{
2207 unsigned long flags = s->flags;
2208 unsigned long size = s->objsize;
2209 unsigned long align = s->align;
Christoph Lameter834f3d12008-04-14 19:11:31 +03002210 int order;
Christoph Lameter81819f02007-05-06 14:49:36 -07002211
2212 /*
Christoph Lameterd8b42bf2008-02-15 23:45:25 -08002213 * Round up object size to the next word boundary. We can only
2214 * place the free pointer at word boundaries and this determines
2215 * the possible location of the free pointer.
2216 */
2217 size = ALIGN(size, sizeof(void *));
2218
2219#ifdef CONFIG_SLUB_DEBUG
2220 /*
Christoph Lameter81819f02007-05-06 14:49:36 -07002221 * Determine if we can poison the object itself. If the user of
2222 * the slab may touch the object after free or before allocation
2223 * then we should never poison the object itself.
2224 */
2225 if ((flags & SLAB_POISON) && !(flags & SLAB_DESTROY_BY_RCU) &&
Christoph Lameterc59def9f2007-05-16 22:10:50 -07002226 !s->ctor)
Christoph Lameter81819f02007-05-06 14:49:36 -07002227 s->flags |= __OBJECT_POISON;
2228 else
2229 s->flags &= ~__OBJECT_POISON;
2230
Christoph Lameter81819f02007-05-06 14:49:36 -07002231
2232 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07002233 * If we are Redzoning then check if there is some space between the
Christoph Lameter81819f02007-05-06 14:49:36 -07002234 * end of the object and the free pointer. If not then add an
Christoph Lameter672bba32007-05-09 02:32:39 -07002235 * additional word to have some bytes to store Redzone information.
Christoph Lameter81819f02007-05-06 14:49:36 -07002236 */
2237 if ((flags & SLAB_RED_ZONE) && size == s->objsize)
2238 size += sizeof(void *);
Christoph Lameter41ecc552007-05-09 02:32:44 -07002239#endif
Christoph Lameter81819f02007-05-06 14:49:36 -07002240
2241 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07002242 * With that we have determined the number of bytes in actual use
2243 * by the object. This is the potential offset to the free pointer.
Christoph Lameter81819f02007-05-06 14:49:36 -07002244 */
2245 s->inuse = size;
2246
2247 if (((flags & (SLAB_DESTROY_BY_RCU | SLAB_POISON)) ||
Christoph Lameterc59def9f2007-05-16 22:10:50 -07002248 s->ctor)) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002249 /*
2250 * Relocate free pointer after the object if it is not
2251 * permitted to overwrite the first word of the object on
2252 * kmem_cache_free.
2253 *
2254 * This is the case if we do RCU, have a constructor or
2255 * destructor or are poisoning the objects.
2256 */
2257 s->offset = size;
2258 size += sizeof(void *);
2259 }
2260
Christoph Lameterc12b3c62007-05-23 13:57:31 -07002261#ifdef CONFIG_SLUB_DEBUG
Christoph Lameter81819f02007-05-06 14:49:36 -07002262 if (flags & SLAB_STORE_USER)
2263 /*
2264 * Need to store information about allocs and frees after
2265 * the object.
2266 */
2267 size += 2 * sizeof(struct track);
2268
Christoph Lameterbe7b3fb2007-05-09 02:32:36 -07002269 if (flags & SLAB_RED_ZONE)
Christoph Lameter81819f02007-05-06 14:49:36 -07002270 /*
2271 * Add some empty padding so that we can catch
2272 * overwrites from earlier objects rather than let
2273 * tracking information or the free pointer be
2274 * corrupted if an user writes before the start
2275 * of the object.
2276 */
2277 size += sizeof(void *);
Christoph Lameter41ecc552007-05-09 02:32:44 -07002278#endif
Christoph Lameter672bba32007-05-09 02:32:39 -07002279
Christoph Lameter81819f02007-05-06 14:49:36 -07002280 /*
2281 * Determine the alignment based on various parameters that the
Christoph Lameter65c02d42007-05-09 02:32:35 -07002282 * user specified and the dynamic determination of cache line size
2283 * on bootup.
Christoph Lameter81819f02007-05-06 14:49:36 -07002284 */
2285 align = calculate_alignment(flags, align, s->objsize);
2286
2287 /*
2288 * SLUB stores one object immediately after another beginning from
2289 * offset 0. In order to align the objects we have to simply size
2290 * each object to conform to the alignment.
2291 */
2292 size = ALIGN(size, align);
2293 s->size = size;
Christoph Lameter06b285d2008-04-14 19:11:41 +03002294 if (forced_order >= 0)
2295 order = forced_order;
2296 else
2297 order = calculate_order(size);
Christoph Lameter81819f02007-05-06 14:49:36 -07002298
Christoph Lameter834f3d12008-04-14 19:11:31 +03002299 if (order < 0)
Christoph Lameter81819f02007-05-06 14:49:36 -07002300 return 0;
2301
Christoph Lameterb7a49f02008-02-14 14:21:32 -08002302 s->allocflags = 0;
Christoph Lameter834f3d12008-04-14 19:11:31 +03002303 if (order)
Christoph Lameterb7a49f02008-02-14 14:21:32 -08002304 s->allocflags |= __GFP_COMP;
2305
2306 if (s->flags & SLAB_CACHE_DMA)
2307 s->allocflags |= SLUB_DMA;
2308
2309 if (s->flags & SLAB_RECLAIM_ACCOUNT)
2310 s->allocflags |= __GFP_RECLAIMABLE;
2311
Christoph Lameter81819f02007-05-06 14:49:36 -07002312 /*
2313 * Determine the number of objects per slab
2314 */
Christoph Lameter834f3d12008-04-14 19:11:31 +03002315 s->oo = oo_make(order, size);
Christoph Lameter65c33762008-04-14 19:11:40 +03002316 s->min = oo_make(get_order(size), size);
Christoph Lameter205ab992008-04-14 19:11:40 +03002317 if (oo_objects(s->oo) > oo_objects(s->max))
2318 s->max = s->oo;
Christoph Lameter81819f02007-05-06 14:49:36 -07002319
Christoph Lameter834f3d12008-04-14 19:11:31 +03002320 return !!oo_objects(s->oo);
Christoph Lameter81819f02007-05-06 14:49:36 -07002321
2322}
2323
Christoph Lameter81819f02007-05-06 14:49:36 -07002324static int kmem_cache_open(struct kmem_cache *s, gfp_t gfpflags,
2325 const char *name, size_t size,
2326 size_t align, unsigned long flags,
Christoph Lameter4ba9b9d2007-10-16 23:25:51 -07002327 void (*ctor)(struct kmem_cache *, void *))
Christoph Lameter81819f02007-05-06 14:49:36 -07002328{
2329 memset(s, 0, kmem_size);
2330 s->name = name;
2331 s->ctor = ctor;
Christoph Lameter81819f02007-05-06 14:49:36 -07002332 s->objsize = size;
Christoph Lameter81819f02007-05-06 14:49:36 -07002333 s->align = align;
Christoph Lameterba0268a2007-09-11 15:24:11 -07002334 s->flags = kmem_cache_flags(size, flags, name, ctor);
Christoph Lameter81819f02007-05-06 14:49:36 -07002335
Christoph Lameter06b285d2008-04-14 19:11:41 +03002336 if (!calculate_sizes(s, -1))
Christoph Lameter81819f02007-05-06 14:49:36 -07002337 goto error;
2338
2339 s->refcount = 1;
2340#ifdef CONFIG_NUMA
Christoph Lameter98246012008-01-07 23:20:26 -08002341 s->remote_node_defrag_ratio = 100;
Christoph Lameter81819f02007-05-06 14:49:36 -07002342#endif
Christoph Lameterdfb4f092007-10-16 01:26:05 -07002343 if (!init_kmem_cache_nodes(s, gfpflags & ~SLUB_DMA))
2344 goto error;
Christoph Lameter81819f02007-05-06 14:49:36 -07002345
Christoph Lameterdfb4f092007-10-16 01:26:05 -07002346 if (alloc_kmem_cache_cpus(s, gfpflags & ~SLUB_DMA))
Christoph Lameter81819f02007-05-06 14:49:36 -07002347 return 1;
Christoph Lameter4c93c3552007-10-16 01:26:08 -07002348 free_kmem_cache_nodes(s);
Christoph Lameter81819f02007-05-06 14:49:36 -07002349error:
2350 if (flags & SLAB_PANIC)
2351 panic("Cannot create slab %s size=%lu realsize=%u "
2352 "order=%u offset=%u flags=%lx\n",
Christoph Lameter834f3d12008-04-14 19:11:31 +03002353 s->name, (unsigned long)size, s->size, oo_order(s->oo),
Christoph Lameter81819f02007-05-06 14:49:36 -07002354 s->offset, flags);
2355 return 0;
2356}
Christoph Lameter81819f02007-05-06 14:49:36 -07002357
2358/*
2359 * Check if a given pointer is valid
2360 */
2361int kmem_ptr_validate(struct kmem_cache *s, const void *object)
2362{
Pekka Enberg06428782008-01-07 23:20:27 -08002363 struct page *page;
Christoph Lameter81819f02007-05-06 14:49:36 -07002364
2365 page = get_object_page(object);
2366
2367 if (!page || s != page->slab)
2368 /* No slab or wrong slab */
2369 return 0;
2370
Christoph Lameterabcd08a2007-05-09 02:32:37 -07002371 if (!check_valid_pointer(s, page, object))
Christoph Lameter81819f02007-05-06 14:49:36 -07002372 return 0;
2373
2374 /*
2375 * We could also check if the object is on the slabs freelist.
2376 * But this would be too expensive and it seems that the main
Christoph Lameter6446faa2008-02-15 23:45:26 -08002377 * purpose of kmem_ptr_valid() is to check if the object belongs
Christoph Lameter81819f02007-05-06 14:49:36 -07002378 * to a certain slab.
2379 */
2380 return 1;
2381}
2382EXPORT_SYMBOL(kmem_ptr_validate);
2383
2384/*
2385 * Determine the size of a slab object
2386 */
2387unsigned int kmem_cache_size(struct kmem_cache *s)
2388{
2389 return s->objsize;
2390}
2391EXPORT_SYMBOL(kmem_cache_size);
2392
2393const char *kmem_cache_name(struct kmem_cache *s)
2394{
2395 return s->name;
2396}
2397EXPORT_SYMBOL(kmem_cache_name);
2398
Christoph Lameter33b12c32008-04-25 12:22:43 -07002399static void list_slab_objects(struct kmem_cache *s, struct page *page,
2400 const char *text)
Christoph Lameter81819f02007-05-06 14:49:36 -07002401{
Christoph Lameter33b12c32008-04-25 12:22:43 -07002402#ifdef CONFIG_SLUB_DEBUG
2403 void *addr = page_address(page);
2404 void *p;
2405 DECLARE_BITMAP(map, page->objects);
2406
2407 bitmap_zero(map, page->objects);
2408 slab_err(s, page, "%s", text);
2409 slab_lock(page);
2410 for_each_free_object(p, s, page->freelist)
2411 set_bit(slab_index(p, s, addr), map);
2412
2413 for_each_object(p, s, addr, page->objects) {
2414
2415 if (!test_bit(slab_index(p, s, addr), map)) {
2416 printk(KERN_ERR "INFO: Object 0x%p @offset=%tu\n",
2417 p, p - addr);
2418 print_tracking(s, p);
2419 }
2420 }
2421 slab_unlock(page);
2422#endif
2423}
2424
Christoph Lameter81819f02007-05-06 14:49:36 -07002425/*
Christoph Lameter599870b2008-04-23 12:36:52 -07002426 * Attempt to free all partial slabs on a node.
Christoph Lameter81819f02007-05-06 14:49:36 -07002427 */
Christoph Lameter599870b2008-04-23 12:36:52 -07002428static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n)
Christoph Lameter81819f02007-05-06 14:49:36 -07002429{
Christoph Lameter81819f02007-05-06 14:49:36 -07002430 unsigned long flags;
2431 struct page *page, *h;
2432
2433 spin_lock_irqsave(&n->list_lock, flags);
Christoph Lameter33b12c32008-04-25 12:22:43 -07002434 list_for_each_entry_safe(page, h, &n->partial, lru) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002435 if (!page->inuse) {
2436 list_del(&page->lru);
2437 discard_slab(s, page);
Christoph Lameter599870b2008-04-23 12:36:52 -07002438 n->nr_partial--;
Christoph Lameter33b12c32008-04-25 12:22:43 -07002439 } else {
2440 list_slab_objects(s, page,
2441 "Objects remaining on kmem_cache_close()");
Christoph Lameter599870b2008-04-23 12:36:52 -07002442 }
Christoph Lameter33b12c32008-04-25 12:22:43 -07002443 }
Christoph Lameter81819f02007-05-06 14:49:36 -07002444 spin_unlock_irqrestore(&n->list_lock, flags);
Christoph Lameter81819f02007-05-06 14:49:36 -07002445}
2446
2447/*
Christoph Lameter672bba32007-05-09 02:32:39 -07002448 * Release all resources used by a slab cache.
Christoph Lameter81819f02007-05-06 14:49:36 -07002449 */
Christoph Lameter0c710012007-07-17 04:03:24 -07002450static inline int kmem_cache_close(struct kmem_cache *s)
Christoph Lameter81819f02007-05-06 14:49:36 -07002451{
2452 int node;
2453
2454 flush_all(s);
2455
2456 /* Attempt to free all objects */
Christoph Lameter4c93c3552007-10-16 01:26:08 -07002457 free_kmem_cache_cpus(s);
Christoph Lameterf64dc582007-10-16 01:25:33 -07002458 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002459 struct kmem_cache_node *n = get_node(s, node);
2460
Christoph Lameter599870b2008-04-23 12:36:52 -07002461 free_partial(s, n);
2462 if (n->nr_partial || slabs_node(s, node))
Christoph Lameter81819f02007-05-06 14:49:36 -07002463 return 1;
2464 }
2465 free_kmem_cache_nodes(s);
2466 return 0;
2467}
2468
2469/*
2470 * Close a cache and release the kmem_cache structure
2471 * (must be used for caches created using kmem_cache_create)
2472 */
2473void kmem_cache_destroy(struct kmem_cache *s)
2474{
2475 down_write(&slub_lock);
2476 s->refcount--;
2477 if (!s->refcount) {
2478 list_del(&s->list);
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07002479 up_write(&slub_lock);
Pekka Enbergd629d812008-04-23 22:31:08 +03002480 if (kmem_cache_close(s)) {
2481 printk(KERN_ERR "SLUB %s: %s called for cache that "
2482 "still has objects.\n", s->name, __func__);
2483 dump_stack();
2484 }
Christoph Lameter81819f02007-05-06 14:49:36 -07002485 sysfs_slab_remove(s);
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07002486 } else
2487 up_write(&slub_lock);
Christoph Lameter81819f02007-05-06 14:49:36 -07002488}
2489EXPORT_SYMBOL(kmem_cache_destroy);
2490
2491/********************************************************************
2492 * Kmalloc subsystem
2493 *******************************************************************/
2494
Christoph Lameter331dc552008-02-14 14:28:09 -08002495struct kmem_cache kmalloc_caches[PAGE_SHIFT + 1] __cacheline_aligned;
Christoph Lameter81819f02007-05-06 14:49:36 -07002496EXPORT_SYMBOL(kmalloc_caches);
2497
Christoph Lameter81819f02007-05-06 14:49:36 -07002498static int __init setup_slub_min_order(char *str)
2499{
Pekka Enberg06428782008-01-07 23:20:27 -08002500 get_option(&str, &slub_min_order);
Christoph Lameter81819f02007-05-06 14:49:36 -07002501
2502 return 1;
2503}
2504
2505__setup("slub_min_order=", setup_slub_min_order);
2506
2507static int __init setup_slub_max_order(char *str)
2508{
Pekka Enberg06428782008-01-07 23:20:27 -08002509 get_option(&str, &slub_max_order);
Christoph Lameter81819f02007-05-06 14:49:36 -07002510
2511 return 1;
2512}
2513
2514__setup("slub_max_order=", setup_slub_max_order);
2515
2516static int __init setup_slub_min_objects(char *str)
2517{
Pekka Enberg06428782008-01-07 23:20:27 -08002518 get_option(&str, &slub_min_objects);
Christoph Lameter81819f02007-05-06 14:49:36 -07002519
2520 return 1;
2521}
2522
2523__setup("slub_min_objects=", setup_slub_min_objects);
2524
2525static int __init setup_slub_nomerge(char *str)
2526{
2527 slub_nomerge = 1;
2528 return 1;
2529}
2530
2531__setup("slub_nomerge", setup_slub_nomerge);
2532
Christoph Lameter81819f02007-05-06 14:49:36 -07002533static struct kmem_cache *create_kmalloc_cache(struct kmem_cache *s,
2534 const char *name, int size, gfp_t gfp_flags)
2535{
2536 unsigned int flags = 0;
2537
2538 if (gfp_flags & SLUB_DMA)
2539 flags = SLAB_CACHE_DMA;
2540
2541 down_write(&slub_lock);
2542 if (!kmem_cache_open(s, gfp_flags, name, size, ARCH_KMALLOC_MINALIGN,
Christoph Lameter319d1e22008-04-14 19:11:41 +03002543 flags, NULL))
Christoph Lameter81819f02007-05-06 14:49:36 -07002544 goto panic;
2545
2546 list_add(&s->list, &slab_caches);
2547 up_write(&slub_lock);
2548 if (sysfs_slab_add(s))
2549 goto panic;
2550 return s;
2551
2552panic:
2553 panic("Creation of kmalloc slab %s size=%d failed.\n", name, size);
2554}
2555
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002556#ifdef CONFIG_ZONE_DMA
Christoph Lameter4097d602008-04-14 18:51:18 +03002557static struct kmem_cache *kmalloc_caches_dma[PAGE_SHIFT + 1];
Christoph Lameter1ceef402007-08-07 15:11:48 -07002558
2559static void sysfs_add_func(struct work_struct *w)
2560{
2561 struct kmem_cache *s;
2562
2563 down_write(&slub_lock);
2564 list_for_each_entry(s, &slab_caches, list) {
2565 if (s->flags & __SYSFS_ADD_DEFERRED) {
2566 s->flags &= ~__SYSFS_ADD_DEFERRED;
2567 sysfs_slab_add(s);
2568 }
2569 }
2570 up_write(&slub_lock);
2571}
2572
2573static DECLARE_WORK(sysfs_add_work, sysfs_add_func);
2574
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002575static noinline struct kmem_cache *dma_kmalloc_cache(int index, gfp_t flags)
2576{
2577 struct kmem_cache *s;
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002578 char *text;
2579 size_t realsize;
2580
2581 s = kmalloc_caches_dma[index];
2582 if (s)
2583 return s;
2584
2585 /* Dynamically create dma cache */
Christoph Lameter1ceef402007-08-07 15:11:48 -07002586 if (flags & __GFP_WAIT)
2587 down_write(&slub_lock);
2588 else {
2589 if (!down_write_trylock(&slub_lock))
2590 goto out;
2591 }
2592
2593 if (kmalloc_caches_dma[index])
2594 goto unlock_out;
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002595
Christoph Lameter7b55f622007-07-17 04:03:27 -07002596 realsize = kmalloc_caches[index].objsize;
Ingo Molnar3adbefe2008-02-05 17:57:39 -08002597 text = kasprintf(flags & ~SLUB_DMA, "kmalloc_dma-%d",
2598 (unsigned int)realsize);
Christoph Lameter1ceef402007-08-07 15:11:48 -07002599 s = kmalloc(kmem_size, flags & ~SLUB_DMA);
2600
2601 if (!s || !text || !kmem_cache_open(s, flags, text,
2602 realsize, ARCH_KMALLOC_MINALIGN,
2603 SLAB_CACHE_DMA|__SYSFS_ADD_DEFERRED, NULL)) {
2604 kfree(s);
2605 kfree(text);
2606 goto unlock_out;
Christoph Lameterdfce8642007-07-17 04:03:25 -07002607 }
Christoph Lameter1ceef402007-08-07 15:11:48 -07002608
2609 list_add(&s->list, &slab_caches);
2610 kmalloc_caches_dma[index] = s;
2611
2612 schedule_work(&sysfs_add_work);
2613
2614unlock_out:
Christoph Lameterdfce8642007-07-17 04:03:25 -07002615 up_write(&slub_lock);
Christoph Lameter1ceef402007-08-07 15:11:48 -07002616out:
Christoph Lameterdfce8642007-07-17 04:03:25 -07002617 return kmalloc_caches_dma[index];
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002618}
2619#endif
2620
Christoph Lameterf1b26332007-07-17 04:03:26 -07002621/*
2622 * Conversion table for small slabs sizes / 8 to the index in the
2623 * kmalloc array. This is necessary for slabs < 192 since we have non power
2624 * of two cache sizes there. The size of larger slabs can be determined using
2625 * fls.
2626 */
2627static s8 size_index[24] = {
2628 3, /* 8 */
2629 4, /* 16 */
2630 5, /* 24 */
2631 5, /* 32 */
2632 6, /* 40 */
2633 6, /* 48 */
2634 6, /* 56 */
2635 6, /* 64 */
2636 1, /* 72 */
2637 1, /* 80 */
2638 1, /* 88 */
2639 1, /* 96 */
2640 7, /* 104 */
2641 7, /* 112 */
2642 7, /* 120 */
2643 7, /* 128 */
2644 2, /* 136 */
2645 2, /* 144 */
2646 2, /* 152 */
2647 2, /* 160 */
2648 2, /* 168 */
2649 2, /* 176 */
2650 2, /* 184 */
2651 2 /* 192 */
2652};
2653
Christoph Lameter81819f02007-05-06 14:49:36 -07002654static struct kmem_cache *get_slab(size_t size, gfp_t flags)
2655{
Christoph Lameterf1b26332007-07-17 04:03:26 -07002656 int index;
Christoph Lameter81819f02007-05-06 14:49:36 -07002657
Christoph Lameterf1b26332007-07-17 04:03:26 -07002658 if (size <= 192) {
2659 if (!size)
2660 return ZERO_SIZE_PTR;
Christoph Lameter81819f02007-05-06 14:49:36 -07002661
Christoph Lameterf1b26332007-07-17 04:03:26 -07002662 index = size_index[(size - 1) / 8];
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002663 } else
Christoph Lameterf1b26332007-07-17 04:03:26 -07002664 index = fls(size - 1);
Christoph Lameter81819f02007-05-06 14:49:36 -07002665
2666#ifdef CONFIG_ZONE_DMA
Christoph Lameterf1b26332007-07-17 04:03:26 -07002667 if (unlikely((flags & SLUB_DMA)))
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002668 return dma_kmalloc_cache(index, flags);
Christoph Lameterf1b26332007-07-17 04:03:26 -07002669
Christoph Lameter81819f02007-05-06 14:49:36 -07002670#endif
2671 return &kmalloc_caches[index];
2672}
2673
2674void *__kmalloc(size_t size, gfp_t flags)
2675{
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002676 struct kmem_cache *s;
Christoph Lameter81819f02007-05-06 14:49:36 -07002677
Christoph Lameter331dc552008-02-14 14:28:09 -08002678 if (unlikely(size > PAGE_SIZE))
Pekka Enbergeada35e2008-02-11 22:47:46 +02002679 return kmalloc_large(size, flags);
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002680
2681 s = get_slab(size, flags);
2682
2683 if (unlikely(ZERO_OR_NULL_PTR(s)))
Christoph Lameter6cb8f912007-07-17 04:03:22 -07002684 return s;
2685
Christoph Lameterce15fea2007-07-17 04:03:28 -07002686 return slab_alloc(s, flags, -1, __builtin_return_address(0));
Christoph Lameter81819f02007-05-06 14:49:36 -07002687}
2688EXPORT_SYMBOL(__kmalloc);
2689
Christoph Lameterf619cfe2008-03-01 13:56:40 -08002690static void *kmalloc_large_node(size_t size, gfp_t flags, int node)
2691{
2692 struct page *page = alloc_pages_node(node, flags | __GFP_COMP,
2693 get_order(size));
2694
2695 if (page)
2696 return page_address(page);
2697 else
2698 return NULL;
2699}
2700
Christoph Lameter81819f02007-05-06 14:49:36 -07002701#ifdef CONFIG_NUMA
2702void *__kmalloc_node(size_t size, gfp_t flags, int node)
2703{
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002704 struct kmem_cache *s;
Christoph Lameter81819f02007-05-06 14:49:36 -07002705
Christoph Lameter331dc552008-02-14 14:28:09 -08002706 if (unlikely(size > PAGE_SIZE))
Christoph Lameterf619cfe2008-03-01 13:56:40 -08002707 return kmalloc_large_node(size, flags, node);
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002708
2709 s = get_slab(size, flags);
2710
2711 if (unlikely(ZERO_OR_NULL_PTR(s)))
Christoph Lameter6cb8f912007-07-17 04:03:22 -07002712 return s;
2713
Christoph Lameterce15fea2007-07-17 04:03:28 -07002714 return slab_alloc(s, flags, node, __builtin_return_address(0));
Christoph Lameter81819f02007-05-06 14:49:36 -07002715}
2716EXPORT_SYMBOL(__kmalloc_node);
2717#endif
2718
2719size_t ksize(const void *object)
2720{
Christoph Lameter272c1d22007-06-08 13:46:49 -07002721 struct page *page;
Christoph Lameter81819f02007-05-06 14:49:36 -07002722 struct kmem_cache *s;
2723
Christoph Lameteref8b4522007-10-16 01:24:46 -07002724 if (unlikely(object == ZERO_SIZE_PTR))
Christoph Lameter272c1d22007-06-08 13:46:49 -07002725 return 0;
2726
Vegard Nossum294a80a2007-12-04 23:45:30 -08002727 page = virt_to_head_page(object);
Vegard Nossum294a80a2007-12-04 23:45:30 -08002728
Pekka Enberg76994412008-05-22 19:22:25 +03002729 if (unlikely(!PageSlab(page))) {
2730 WARN_ON(!PageCompound(page));
Vegard Nossum294a80a2007-12-04 23:45:30 -08002731 return PAGE_SIZE << compound_order(page);
Pekka Enberg76994412008-05-22 19:22:25 +03002732 }
Christoph Lameter81819f02007-05-06 14:49:36 -07002733 s = page->slab;
Christoph Lameter81819f02007-05-06 14:49:36 -07002734
Christoph Lameterae20bfd2008-02-15 23:45:25 -08002735#ifdef CONFIG_SLUB_DEBUG
Christoph Lameter81819f02007-05-06 14:49:36 -07002736 /*
2737 * Debugging requires use of the padding between object
2738 * and whatever may come after it.
2739 */
2740 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
2741 return s->objsize;
2742
Christoph Lameterae20bfd2008-02-15 23:45:25 -08002743#endif
Christoph Lameter81819f02007-05-06 14:49:36 -07002744 /*
2745 * If we have the need to store the freelist pointer
2746 * back there or track user information then we can
2747 * only use the space before that information.
2748 */
2749 if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER))
2750 return s->inuse;
Christoph Lameter81819f02007-05-06 14:49:36 -07002751 /*
2752 * Else we can use all the padding etc for the allocation
2753 */
2754 return s->size;
2755}
2756EXPORT_SYMBOL(ksize);
2757
2758void kfree(const void *x)
2759{
Christoph Lameter81819f02007-05-06 14:49:36 -07002760 struct page *page;
Christoph Lameter5bb983b2008-02-07 17:47:41 -08002761 void *object = (void *)x;
Christoph Lameter81819f02007-05-06 14:49:36 -07002762
Satyam Sharma2408c552007-10-16 01:24:44 -07002763 if (unlikely(ZERO_OR_NULL_PTR(x)))
Christoph Lameter81819f02007-05-06 14:49:36 -07002764 return;
2765
Christoph Lameterb49af682007-05-06 14:49:41 -07002766 page = virt_to_head_page(x);
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002767 if (unlikely(!PageSlab(page))) {
2768 put_page(page);
2769 return;
2770 }
Christoph Lameter5bb983b2008-02-07 17:47:41 -08002771 slab_free(page->slab, page, object, __builtin_return_address(0));
Christoph Lameter81819f02007-05-06 14:49:36 -07002772}
2773EXPORT_SYMBOL(kfree);
2774
Christoph Lameter2086d262007-05-06 14:49:46 -07002775/*
Christoph Lameter672bba32007-05-09 02:32:39 -07002776 * kmem_cache_shrink removes empty slabs from the partial lists and sorts
2777 * the remaining slabs by the number of items in use. The slabs with the
2778 * most items in use come first. New allocations will then fill those up
2779 * and thus they can be removed from the partial lists.
2780 *
2781 * The slabs with the least items are placed last. This results in them
2782 * being allocated from last increasing the chance that the last objects
2783 * are freed in them.
Christoph Lameter2086d262007-05-06 14:49:46 -07002784 */
2785int kmem_cache_shrink(struct kmem_cache *s)
2786{
2787 int node;
2788 int i;
2789 struct kmem_cache_node *n;
2790 struct page *page;
2791 struct page *t;
Christoph Lameter205ab992008-04-14 19:11:40 +03002792 int objects = oo_objects(s->max);
Christoph Lameter2086d262007-05-06 14:49:46 -07002793 struct list_head *slabs_by_inuse =
Christoph Lameter834f3d12008-04-14 19:11:31 +03002794 kmalloc(sizeof(struct list_head) * objects, GFP_KERNEL);
Christoph Lameter2086d262007-05-06 14:49:46 -07002795 unsigned long flags;
2796
2797 if (!slabs_by_inuse)
2798 return -ENOMEM;
2799
2800 flush_all(s);
Christoph Lameterf64dc582007-10-16 01:25:33 -07002801 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter2086d262007-05-06 14:49:46 -07002802 n = get_node(s, node);
2803
2804 if (!n->nr_partial)
2805 continue;
2806
Christoph Lameter834f3d12008-04-14 19:11:31 +03002807 for (i = 0; i < objects; i++)
Christoph Lameter2086d262007-05-06 14:49:46 -07002808 INIT_LIST_HEAD(slabs_by_inuse + i);
2809
2810 spin_lock_irqsave(&n->list_lock, flags);
2811
2812 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07002813 * Build lists indexed by the items in use in each slab.
Christoph Lameter2086d262007-05-06 14:49:46 -07002814 *
Christoph Lameter672bba32007-05-09 02:32:39 -07002815 * Note that concurrent frees may occur while we hold the
2816 * list_lock. page->inuse here is the upper limit.
Christoph Lameter2086d262007-05-06 14:49:46 -07002817 */
2818 list_for_each_entry_safe(page, t, &n->partial, lru) {
2819 if (!page->inuse && slab_trylock(page)) {
2820 /*
2821 * Must hold slab lock here because slab_free
2822 * may have freed the last object and be
2823 * waiting to release the slab.
2824 */
2825 list_del(&page->lru);
2826 n->nr_partial--;
2827 slab_unlock(page);
2828 discard_slab(s, page);
2829 } else {
Christoph Lameterfcda3d82007-07-30 13:06:46 -07002830 list_move(&page->lru,
2831 slabs_by_inuse + page->inuse);
Christoph Lameter2086d262007-05-06 14:49:46 -07002832 }
2833 }
2834
Christoph Lameter2086d262007-05-06 14:49:46 -07002835 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07002836 * Rebuild the partial list with the slabs filled up most
2837 * first and the least used slabs at the end.
Christoph Lameter2086d262007-05-06 14:49:46 -07002838 */
Christoph Lameter834f3d12008-04-14 19:11:31 +03002839 for (i = objects - 1; i >= 0; i--)
Christoph Lameter2086d262007-05-06 14:49:46 -07002840 list_splice(slabs_by_inuse + i, n->partial.prev);
2841
Christoph Lameter2086d262007-05-06 14:49:46 -07002842 spin_unlock_irqrestore(&n->list_lock, flags);
2843 }
2844
2845 kfree(slabs_by_inuse);
2846 return 0;
2847}
2848EXPORT_SYMBOL(kmem_cache_shrink);
2849
Yasunori Gotob9049e22007-10-21 16:41:37 -07002850#if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)
2851static int slab_mem_going_offline_callback(void *arg)
2852{
2853 struct kmem_cache *s;
2854
2855 down_read(&slub_lock);
2856 list_for_each_entry(s, &slab_caches, list)
2857 kmem_cache_shrink(s);
2858 up_read(&slub_lock);
2859
2860 return 0;
2861}
2862
2863static void slab_mem_offline_callback(void *arg)
2864{
2865 struct kmem_cache_node *n;
2866 struct kmem_cache *s;
2867 struct memory_notify *marg = arg;
2868 int offline_node;
2869
2870 offline_node = marg->status_change_nid;
2871
2872 /*
2873 * If the node still has available memory. we need kmem_cache_node
2874 * for it yet.
2875 */
2876 if (offline_node < 0)
2877 return;
2878
2879 down_read(&slub_lock);
2880 list_for_each_entry(s, &slab_caches, list) {
2881 n = get_node(s, offline_node);
2882 if (n) {
2883 /*
2884 * if n->nr_slabs > 0, slabs still exist on the node
2885 * that is going down. We were unable to free them,
2886 * and offline_pages() function shoudn't call this
2887 * callback. So, we must fail.
2888 */
Christoph Lameter0f389ec2008-04-14 18:53:02 +03002889 BUG_ON(slabs_node(s, offline_node));
Yasunori Gotob9049e22007-10-21 16:41:37 -07002890
2891 s->node[offline_node] = NULL;
2892 kmem_cache_free(kmalloc_caches, n);
2893 }
2894 }
2895 up_read(&slub_lock);
2896}
2897
2898static int slab_mem_going_online_callback(void *arg)
2899{
2900 struct kmem_cache_node *n;
2901 struct kmem_cache *s;
2902 struct memory_notify *marg = arg;
2903 int nid = marg->status_change_nid;
2904 int ret = 0;
2905
2906 /*
2907 * If the node's memory is already available, then kmem_cache_node is
2908 * already created. Nothing to do.
2909 */
2910 if (nid < 0)
2911 return 0;
2912
2913 /*
Christoph Lameter0121c6192008-04-29 16:11:12 -07002914 * We are bringing a node online. No memory is available yet. We must
Yasunori Gotob9049e22007-10-21 16:41:37 -07002915 * allocate a kmem_cache_node structure in order to bring the node
2916 * online.
2917 */
2918 down_read(&slub_lock);
2919 list_for_each_entry(s, &slab_caches, list) {
2920 /*
2921 * XXX: kmem_cache_alloc_node will fallback to other nodes
2922 * since memory is not yet available from the node that
2923 * is brought up.
2924 */
2925 n = kmem_cache_alloc(kmalloc_caches, GFP_KERNEL);
2926 if (!n) {
2927 ret = -ENOMEM;
2928 goto out;
2929 }
2930 init_kmem_cache_node(n);
2931 s->node[nid] = n;
2932 }
2933out:
2934 up_read(&slub_lock);
2935 return ret;
2936}
2937
2938static int slab_memory_callback(struct notifier_block *self,
2939 unsigned long action, void *arg)
2940{
2941 int ret = 0;
2942
2943 switch (action) {
2944 case MEM_GOING_ONLINE:
2945 ret = slab_mem_going_online_callback(arg);
2946 break;
2947 case MEM_GOING_OFFLINE:
2948 ret = slab_mem_going_offline_callback(arg);
2949 break;
2950 case MEM_OFFLINE:
2951 case MEM_CANCEL_ONLINE:
2952 slab_mem_offline_callback(arg);
2953 break;
2954 case MEM_ONLINE:
2955 case MEM_CANCEL_OFFLINE:
2956 break;
2957 }
2958
2959 ret = notifier_from_errno(ret);
2960 return ret;
2961}
2962
2963#endif /* CONFIG_MEMORY_HOTPLUG */
2964
Christoph Lameter81819f02007-05-06 14:49:36 -07002965/********************************************************************
2966 * Basic setup of slabs
2967 *******************************************************************/
2968
2969void __init kmem_cache_init(void)
2970{
2971 int i;
Christoph Lameter4b356be2007-06-16 10:16:13 -07002972 int caches = 0;
Christoph Lameter81819f02007-05-06 14:49:36 -07002973
Christoph Lameter4c93c3552007-10-16 01:26:08 -07002974 init_alloc_cpu();
2975
Christoph Lameter81819f02007-05-06 14:49:36 -07002976#ifdef CONFIG_NUMA
2977 /*
2978 * Must first have the slab cache available for the allocations of the
Christoph Lameter672bba32007-05-09 02:32:39 -07002979 * struct kmem_cache_node's. There is special bootstrap code in
Christoph Lameter81819f02007-05-06 14:49:36 -07002980 * kmem_cache_open for slab_state == DOWN.
2981 */
2982 create_kmalloc_cache(&kmalloc_caches[0], "kmem_cache_node",
2983 sizeof(struct kmem_cache_node), GFP_KERNEL);
Christoph Lameter8ffa6872007-05-31 00:40:51 -07002984 kmalloc_caches[0].refcount = -1;
Christoph Lameter4b356be2007-06-16 10:16:13 -07002985 caches++;
Yasunori Gotob9049e22007-10-21 16:41:37 -07002986
Nadia Derbey0c40ba42008-04-29 01:00:41 -07002987 hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI);
Christoph Lameter81819f02007-05-06 14:49:36 -07002988#endif
2989
2990 /* Able to allocate the per node structures */
2991 slab_state = PARTIAL;
2992
2993 /* Caches that are not of the two-to-the-power-of size */
Christoph Lameter4b356be2007-06-16 10:16:13 -07002994 if (KMALLOC_MIN_SIZE <= 64) {
2995 create_kmalloc_cache(&kmalloc_caches[1],
Christoph Lameter81819f02007-05-06 14:49:36 -07002996 "kmalloc-96", 96, GFP_KERNEL);
Christoph Lameter4b356be2007-06-16 10:16:13 -07002997 caches++;
2998 }
2999 if (KMALLOC_MIN_SIZE <= 128) {
3000 create_kmalloc_cache(&kmalloc_caches[2],
Christoph Lameter81819f02007-05-06 14:49:36 -07003001 "kmalloc-192", 192, GFP_KERNEL);
Christoph Lameter4b356be2007-06-16 10:16:13 -07003002 caches++;
3003 }
Christoph Lameter81819f02007-05-06 14:49:36 -07003004
Christoph Lameter331dc552008-02-14 14:28:09 -08003005 for (i = KMALLOC_SHIFT_LOW; i <= PAGE_SHIFT; i++) {
Christoph Lameter81819f02007-05-06 14:49:36 -07003006 create_kmalloc_cache(&kmalloc_caches[i],
3007 "kmalloc", 1 << i, GFP_KERNEL);
Christoph Lameter4b356be2007-06-16 10:16:13 -07003008 caches++;
3009 }
Christoph Lameter81819f02007-05-06 14:49:36 -07003010
Christoph Lameterf1b26332007-07-17 04:03:26 -07003011
3012 /*
3013 * Patch up the size_index table if we have strange large alignment
3014 * requirements for the kmalloc array. This is only the case for
Christoph Lameter6446faa2008-02-15 23:45:26 -08003015 * MIPS it seems. The standard arches will not generate any code here.
Christoph Lameterf1b26332007-07-17 04:03:26 -07003016 *
3017 * Largest permitted alignment is 256 bytes due to the way we
3018 * handle the index determination for the smaller caches.
3019 *
3020 * Make sure that nothing crazy happens if someone starts tinkering
3021 * around with ARCH_KMALLOC_MINALIGN
3022 */
3023 BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
3024 (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
3025
Christoph Lameter12ad6842007-07-17 04:03:28 -07003026 for (i = 8; i < KMALLOC_MIN_SIZE; i += 8)
Christoph Lameterf1b26332007-07-17 04:03:26 -07003027 size_index[(i - 1) / 8] = KMALLOC_SHIFT_LOW;
3028
Christoph Lameter81819f02007-05-06 14:49:36 -07003029 slab_state = UP;
3030
3031 /* Provide the correct kmalloc names now that the caches are up */
Christoph Lameter331dc552008-02-14 14:28:09 -08003032 for (i = KMALLOC_SHIFT_LOW; i <= PAGE_SHIFT; i++)
Christoph Lameter81819f02007-05-06 14:49:36 -07003033 kmalloc_caches[i]. name =
3034 kasprintf(GFP_KERNEL, "kmalloc-%d", 1 << i);
3035
3036#ifdef CONFIG_SMP
3037 register_cpu_notifier(&slab_notifier);
Christoph Lameter4c93c3552007-10-16 01:26:08 -07003038 kmem_size = offsetof(struct kmem_cache, cpu_slab) +
3039 nr_cpu_ids * sizeof(struct kmem_cache_cpu *);
3040#else
3041 kmem_size = sizeof(struct kmem_cache);
Christoph Lameter81819f02007-05-06 14:49:36 -07003042#endif
3043
Ingo Molnar3adbefe2008-02-05 17:57:39 -08003044 printk(KERN_INFO
3045 "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d,"
Christoph Lameter4b356be2007-06-16 10:16:13 -07003046 " CPUs=%d, Nodes=%d\n",
3047 caches, cache_line_size(),
Christoph Lameter81819f02007-05-06 14:49:36 -07003048 slub_min_order, slub_max_order, slub_min_objects,
3049 nr_cpu_ids, nr_node_ids);
3050}
3051
3052/*
3053 * Find a mergeable slab cache
3054 */
3055static int slab_unmergeable(struct kmem_cache *s)
3056{
3057 if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE))
3058 return 1;
3059
Christoph Lameterc59def9f2007-05-16 22:10:50 -07003060 if (s->ctor)
Christoph Lameter81819f02007-05-06 14:49:36 -07003061 return 1;
3062
Christoph Lameter8ffa6872007-05-31 00:40:51 -07003063 /*
3064 * We may have set a slab to be unmergeable during bootstrap.
3065 */
3066 if (s->refcount < 0)
3067 return 1;
3068
Christoph Lameter81819f02007-05-06 14:49:36 -07003069 return 0;
3070}
3071
3072static struct kmem_cache *find_mergeable(size_t size,
Christoph Lameterba0268a2007-09-11 15:24:11 -07003073 size_t align, unsigned long flags, const char *name,
Christoph Lameter4ba9b9d2007-10-16 23:25:51 -07003074 void (*ctor)(struct kmem_cache *, void *))
Christoph Lameter81819f02007-05-06 14:49:36 -07003075{
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07003076 struct kmem_cache *s;
Christoph Lameter81819f02007-05-06 14:49:36 -07003077
3078 if (slub_nomerge || (flags & SLUB_NEVER_MERGE))
3079 return NULL;
3080
Christoph Lameterc59def9f2007-05-16 22:10:50 -07003081 if (ctor)
Christoph Lameter81819f02007-05-06 14:49:36 -07003082 return NULL;
3083
3084 size = ALIGN(size, sizeof(void *));
3085 align = calculate_alignment(flags, align, size);
3086 size = ALIGN(size, align);
Christoph Lameterba0268a2007-09-11 15:24:11 -07003087 flags = kmem_cache_flags(size, flags, name, NULL);
Christoph Lameter81819f02007-05-06 14:49:36 -07003088
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07003089 list_for_each_entry(s, &slab_caches, list) {
Christoph Lameter81819f02007-05-06 14:49:36 -07003090 if (slab_unmergeable(s))
3091 continue;
3092
3093 if (size > s->size)
3094 continue;
3095
Christoph Lameterba0268a2007-09-11 15:24:11 -07003096 if ((flags & SLUB_MERGE_SAME) != (s->flags & SLUB_MERGE_SAME))
Christoph Lameter81819f02007-05-06 14:49:36 -07003097 continue;
3098 /*
3099 * Check if alignment is compatible.
3100 * Courtesy of Adrian Drzewiecki
3101 */
Pekka Enberg06428782008-01-07 23:20:27 -08003102 if ((s->size & ~(align - 1)) != s->size)
Christoph Lameter81819f02007-05-06 14:49:36 -07003103 continue;
3104
3105 if (s->size - size >= sizeof(void *))
3106 continue;
3107
3108 return s;
3109 }
3110 return NULL;
3111}
3112
3113struct kmem_cache *kmem_cache_create(const char *name, size_t size,
3114 size_t align, unsigned long flags,
Christoph Lameter4ba9b9d2007-10-16 23:25:51 -07003115 void (*ctor)(struct kmem_cache *, void *))
Christoph Lameter81819f02007-05-06 14:49:36 -07003116{
3117 struct kmem_cache *s;
3118
3119 down_write(&slub_lock);
Christoph Lameterba0268a2007-09-11 15:24:11 -07003120 s = find_mergeable(size, align, flags, name, ctor);
Christoph Lameter81819f02007-05-06 14:49:36 -07003121 if (s) {
Christoph Lameter42a9fdb2007-10-16 01:26:09 -07003122 int cpu;
3123
Christoph Lameter81819f02007-05-06 14:49:36 -07003124 s->refcount++;
3125 /*
3126 * Adjust the object sizes so that we clear
3127 * the complete object on kzalloc.
3128 */
3129 s->objsize = max(s->objsize, (int)size);
Christoph Lameter42a9fdb2007-10-16 01:26:09 -07003130
3131 /*
3132 * And then we need to update the object size in the
3133 * per cpu structures
3134 */
3135 for_each_online_cpu(cpu)
3136 get_cpu_slab(s, cpu)->objsize = s->objsize;
Christoph Lameter6446faa2008-02-15 23:45:26 -08003137
Christoph Lameter81819f02007-05-06 14:49:36 -07003138 s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *)));
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07003139 up_write(&slub_lock);
Christoph Lameter6446faa2008-02-15 23:45:26 -08003140
Christoph Lameter81819f02007-05-06 14:49:36 -07003141 if (sysfs_slab_alias(s, name))
3142 goto err;
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07003143 return s;
3144 }
Christoph Lameter6446faa2008-02-15 23:45:26 -08003145
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07003146 s = kmalloc(kmem_size, GFP_KERNEL);
3147 if (s) {
3148 if (kmem_cache_open(s, GFP_KERNEL, name,
Christoph Lameterc59def9f2007-05-16 22:10:50 -07003149 size, align, flags, ctor)) {
Christoph Lameter81819f02007-05-06 14:49:36 -07003150 list_add(&s->list, &slab_caches);
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07003151 up_write(&slub_lock);
3152 if (sysfs_slab_add(s))
3153 goto err;
3154 return s;
3155 }
3156 kfree(s);
Christoph Lameter81819f02007-05-06 14:49:36 -07003157 }
3158 up_write(&slub_lock);
Christoph Lameter81819f02007-05-06 14:49:36 -07003159
3160err:
Christoph Lameter81819f02007-05-06 14:49:36 -07003161 if (flags & SLAB_PANIC)
3162 panic("Cannot create slabcache %s\n", name);
3163 else
3164 s = NULL;
3165 return s;
3166}
3167EXPORT_SYMBOL(kmem_cache_create);
3168
Christoph Lameter81819f02007-05-06 14:49:36 -07003169#ifdef CONFIG_SMP
Christoph Lameter27390bc2007-06-01 00:47:09 -07003170/*
Christoph Lameter672bba32007-05-09 02:32:39 -07003171 * Use the cpu notifier to insure that the cpu slabs are flushed when
3172 * necessary.
Christoph Lameter81819f02007-05-06 14:49:36 -07003173 */
3174static int __cpuinit slab_cpuup_callback(struct notifier_block *nfb,
3175 unsigned long action, void *hcpu)
3176{
3177 long cpu = (long)hcpu;
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07003178 struct kmem_cache *s;
3179 unsigned long flags;
Christoph Lameter81819f02007-05-06 14:49:36 -07003180
3181 switch (action) {
Christoph Lameter4c93c3552007-10-16 01:26:08 -07003182 case CPU_UP_PREPARE:
3183 case CPU_UP_PREPARE_FROZEN:
3184 init_alloc_cpu_cpu(cpu);
3185 down_read(&slub_lock);
3186 list_for_each_entry(s, &slab_caches, list)
3187 s->cpu_slab[cpu] = alloc_kmem_cache_cpu(s, cpu,
3188 GFP_KERNEL);
3189 up_read(&slub_lock);
3190 break;
3191
Christoph Lameter81819f02007-05-06 14:49:36 -07003192 case CPU_UP_CANCELED:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07003193 case CPU_UP_CANCELED_FROZEN:
Christoph Lameter81819f02007-05-06 14:49:36 -07003194 case CPU_DEAD:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07003195 case CPU_DEAD_FROZEN:
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07003196 down_read(&slub_lock);
3197 list_for_each_entry(s, &slab_caches, list) {
Christoph Lameter4c93c3552007-10-16 01:26:08 -07003198 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
3199
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07003200 local_irq_save(flags);
3201 __flush_cpu_slab(s, cpu);
3202 local_irq_restore(flags);
Christoph Lameter4c93c3552007-10-16 01:26:08 -07003203 free_kmem_cache_cpu(c, cpu);
3204 s->cpu_slab[cpu] = NULL;
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07003205 }
3206 up_read(&slub_lock);
Christoph Lameter81819f02007-05-06 14:49:36 -07003207 break;
3208 default:
3209 break;
3210 }
3211 return NOTIFY_OK;
3212}
3213
Pekka Enberg06428782008-01-07 23:20:27 -08003214static struct notifier_block __cpuinitdata slab_notifier = {
Ingo Molnar3adbefe2008-02-05 17:57:39 -08003215 .notifier_call = slab_cpuup_callback
Pekka Enberg06428782008-01-07 23:20:27 -08003216};
Christoph Lameter81819f02007-05-06 14:49:36 -07003217
3218#endif
3219
Christoph Lameter81819f02007-05-06 14:49:36 -07003220void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, void *caller)
3221{
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07003222 struct kmem_cache *s;
3223
Christoph Lameter331dc552008-02-14 14:28:09 -08003224 if (unlikely(size > PAGE_SIZE))
Pekka Enbergeada35e2008-02-11 22:47:46 +02003225 return kmalloc_large(size, gfpflags);
3226
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07003227 s = get_slab(size, gfpflags);
Christoph Lameter81819f02007-05-06 14:49:36 -07003228
Satyam Sharma2408c552007-10-16 01:24:44 -07003229 if (unlikely(ZERO_OR_NULL_PTR(s)))
Christoph Lameter6cb8f912007-07-17 04:03:22 -07003230 return s;
Christoph Lameter81819f02007-05-06 14:49:36 -07003231
Christoph Lameterce15fea2007-07-17 04:03:28 -07003232 return slab_alloc(s, gfpflags, -1, caller);
Christoph Lameter81819f02007-05-06 14:49:36 -07003233}
3234
3235void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
3236 int node, void *caller)
3237{
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07003238 struct kmem_cache *s;
3239
Christoph Lameter331dc552008-02-14 14:28:09 -08003240 if (unlikely(size > PAGE_SIZE))
Christoph Lameterf619cfe2008-03-01 13:56:40 -08003241 return kmalloc_large_node(size, gfpflags, node);
Pekka Enbergeada35e2008-02-11 22:47:46 +02003242
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07003243 s = get_slab(size, gfpflags);
Christoph Lameter81819f02007-05-06 14:49:36 -07003244
Satyam Sharma2408c552007-10-16 01:24:44 -07003245 if (unlikely(ZERO_OR_NULL_PTR(s)))
Christoph Lameter6cb8f912007-07-17 04:03:22 -07003246 return s;
Christoph Lameter81819f02007-05-06 14:49:36 -07003247
Christoph Lameterce15fea2007-07-17 04:03:28 -07003248 return slab_alloc(s, gfpflags, node, caller);
Christoph Lameter81819f02007-05-06 14:49:36 -07003249}
3250
Christoph Lameterf6acb632008-04-29 16:16:06 -07003251#ifdef CONFIG_SLUB_DEBUG
Christoph Lameter205ab992008-04-14 19:11:40 +03003252static unsigned long count_partial(struct kmem_cache_node *n,
3253 int (*get_count)(struct page *))
Christoph Lameter5b06c8532008-04-14 18:51:34 +03003254{
3255 unsigned long flags;
3256 unsigned long x = 0;
3257 struct page *page;
3258
3259 spin_lock_irqsave(&n->list_lock, flags);
3260 list_for_each_entry(page, &n->partial, lru)
Christoph Lameter205ab992008-04-14 19:11:40 +03003261 x += get_count(page);
Christoph Lameter5b06c8532008-04-14 18:51:34 +03003262 spin_unlock_irqrestore(&n->list_lock, flags);
3263 return x;
3264}
Christoph Lameter205ab992008-04-14 19:11:40 +03003265
3266static int count_inuse(struct page *page)
3267{
3268 return page->inuse;
3269}
3270
3271static int count_total(struct page *page)
3272{
3273 return page->objects;
3274}
3275
3276static int count_free(struct page *page)
3277{
3278 return page->objects - page->inuse;
3279}
Christoph Lameter5b06c8532008-04-14 18:51:34 +03003280
Christoph Lameter434e2452007-07-17 04:03:30 -07003281static int validate_slab(struct kmem_cache *s, struct page *page,
3282 unsigned long *map)
Christoph Lameter53e15af2007-05-06 14:49:43 -07003283{
3284 void *p;
Christoph Lametera973e9d2008-03-01 13:40:44 -08003285 void *addr = page_address(page);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003286
3287 if (!check_slab(s, page) ||
3288 !on_freelist(s, page, NULL))
3289 return 0;
3290
3291 /* Now we know that a valid freelist exists */
Christoph Lameter39b26462008-04-14 19:11:30 +03003292 bitmap_zero(map, page->objects);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003293
Christoph Lameter7656c722007-05-09 02:32:40 -07003294 for_each_free_object(p, s, page->freelist) {
3295 set_bit(slab_index(p, s, addr), map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003296 if (!check_object(s, page, p, 0))
3297 return 0;
3298 }
3299
Christoph Lameter224a88b2008-04-14 19:11:31 +03003300 for_each_object(p, s, addr, page->objects)
Christoph Lameter7656c722007-05-09 02:32:40 -07003301 if (!test_bit(slab_index(p, s, addr), map))
Christoph Lameter53e15af2007-05-06 14:49:43 -07003302 if (!check_object(s, page, p, 1))
3303 return 0;
3304 return 1;
3305}
3306
Christoph Lameter434e2452007-07-17 04:03:30 -07003307static void validate_slab_slab(struct kmem_cache *s, struct page *page,
3308 unsigned long *map)
Christoph Lameter53e15af2007-05-06 14:49:43 -07003309{
3310 if (slab_trylock(page)) {
Christoph Lameter434e2452007-07-17 04:03:30 -07003311 validate_slab(s, page, map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003312 slab_unlock(page);
3313 } else
3314 printk(KERN_INFO "SLUB %s: Skipped busy slab 0x%p\n",
3315 s->name, page);
3316
3317 if (s->flags & DEBUG_DEFAULT_FLAGS) {
Christoph Lameter35e5d7e2007-05-09 02:32:42 -07003318 if (!SlabDebug(page))
3319 printk(KERN_ERR "SLUB %s: SlabDebug not set "
Christoph Lameter53e15af2007-05-06 14:49:43 -07003320 "on slab 0x%p\n", s->name, page);
3321 } else {
Christoph Lameter35e5d7e2007-05-09 02:32:42 -07003322 if (SlabDebug(page))
3323 printk(KERN_ERR "SLUB %s: SlabDebug set on "
Christoph Lameter53e15af2007-05-06 14:49:43 -07003324 "slab 0x%p\n", s->name, page);
3325 }
3326}
3327
Christoph Lameter434e2452007-07-17 04:03:30 -07003328static int validate_slab_node(struct kmem_cache *s,
3329 struct kmem_cache_node *n, unsigned long *map)
Christoph Lameter53e15af2007-05-06 14:49:43 -07003330{
3331 unsigned long count = 0;
3332 struct page *page;
3333 unsigned long flags;
3334
3335 spin_lock_irqsave(&n->list_lock, flags);
3336
3337 list_for_each_entry(page, &n->partial, lru) {
Christoph Lameter434e2452007-07-17 04:03:30 -07003338 validate_slab_slab(s, page, map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003339 count++;
3340 }
3341 if (count != n->nr_partial)
3342 printk(KERN_ERR "SLUB %s: %ld partial slabs counted but "
3343 "counter=%ld\n", s->name, count, n->nr_partial);
3344
3345 if (!(s->flags & SLAB_STORE_USER))
3346 goto out;
3347
3348 list_for_each_entry(page, &n->full, lru) {
Christoph Lameter434e2452007-07-17 04:03:30 -07003349 validate_slab_slab(s, page, map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003350 count++;
3351 }
3352 if (count != atomic_long_read(&n->nr_slabs))
3353 printk(KERN_ERR "SLUB: %s %ld slabs counted but "
3354 "counter=%ld\n", s->name, count,
3355 atomic_long_read(&n->nr_slabs));
3356
3357out:
3358 spin_unlock_irqrestore(&n->list_lock, flags);
3359 return count;
3360}
3361
Christoph Lameter434e2452007-07-17 04:03:30 -07003362static long validate_slab_cache(struct kmem_cache *s)
Christoph Lameter53e15af2007-05-06 14:49:43 -07003363{
3364 int node;
3365 unsigned long count = 0;
Christoph Lameter205ab992008-04-14 19:11:40 +03003366 unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) *
Christoph Lameter434e2452007-07-17 04:03:30 -07003367 sizeof(unsigned long), GFP_KERNEL);
3368
3369 if (!map)
3370 return -ENOMEM;
Christoph Lameter53e15af2007-05-06 14:49:43 -07003371
3372 flush_all(s);
Christoph Lameterf64dc582007-10-16 01:25:33 -07003373 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter53e15af2007-05-06 14:49:43 -07003374 struct kmem_cache_node *n = get_node(s, node);
3375
Christoph Lameter434e2452007-07-17 04:03:30 -07003376 count += validate_slab_node(s, n, map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003377 }
Christoph Lameter434e2452007-07-17 04:03:30 -07003378 kfree(map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003379 return count;
3380}
3381
Christoph Lameterb3459702007-05-09 02:32:41 -07003382#ifdef SLUB_RESILIENCY_TEST
3383static void resiliency_test(void)
3384{
3385 u8 *p;
3386
3387 printk(KERN_ERR "SLUB resiliency testing\n");
3388 printk(KERN_ERR "-----------------------\n");
3389 printk(KERN_ERR "A. Corruption after allocation\n");
3390
3391 p = kzalloc(16, GFP_KERNEL);
3392 p[16] = 0x12;
3393 printk(KERN_ERR "\n1. kmalloc-16: Clobber Redzone/next pointer"
3394 " 0x12->0x%p\n\n", p + 16);
3395
3396 validate_slab_cache(kmalloc_caches + 4);
3397
3398 /* Hmmm... The next two are dangerous */
3399 p = kzalloc(32, GFP_KERNEL);
3400 p[32 + sizeof(void *)] = 0x34;
3401 printk(KERN_ERR "\n2. kmalloc-32: Clobber next pointer/next slab"
Ingo Molnar3adbefe2008-02-05 17:57:39 -08003402 " 0x34 -> -0x%p\n", p);
3403 printk(KERN_ERR
3404 "If allocated object is overwritten then not detectable\n\n");
Christoph Lameterb3459702007-05-09 02:32:41 -07003405
3406 validate_slab_cache(kmalloc_caches + 5);
3407 p = kzalloc(64, GFP_KERNEL);
3408 p += 64 + (get_cycles() & 0xff) * sizeof(void *);
3409 *p = 0x56;
3410 printk(KERN_ERR "\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n",
3411 p);
Ingo Molnar3adbefe2008-02-05 17:57:39 -08003412 printk(KERN_ERR
3413 "If allocated object is overwritten then not detectable\n\n");
Christoph Lameterb3459702007-05-09 02:32:41 -07003414 validate_slab_cache(kmalloc_caches + 6);
3415
3416 printk(KERN_ERR "\nB. Corruption after free\n");
3417 p = kzalloc(128, GFP_KERNEL);
3418 kfree(p);
3419 *p = 0x78;
3420 printk(KERN_ERR "1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p);
3421 validate_slab_cache(kmalloc_caches + 7);
3422
3423 p = kzalloc(256, GFP_KERNEL);
3424 kfree(p);
3425 p[50] = 0x9a;
Ingo Molnar3adbefe2008-02-05 17:57:39 -08003426 printk(KERN_ERR "\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n",
3427 p);
Christoph Lameterb3459702007-05-09 02:32:41 -07003428 validate_slab_cache(kmalloc_caches + 8);
3429
3430 p = kzalloc(512, GFP_KERNEL);
3431 kfree(p);
3432 p[512] = 0xab;
3433 printk(KERN_ERR "\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p);
3434 validate_slab_cache(kmalloc_caches + 9);
3435}
3436#else
3437static void resiliency_test(void) {};
3438#endif
3439
Christoph Lameter88a420e2007-05-06 14:49:45 -07003440/*
Christoph Lameter672bba32007-05-09 02:32:39 -07003441 * Generate lists of code addresses where slabcache objects are allocated
Christoph Lameter88a420e2007-05-06 14:49:45 -07003442 * and freed.
3443 */
3444
3445struct location {
3446 unsigned long count;
3447 void *addr;
Christoph Lameter45edfa52007-05-09 02:32:45 -07003448 long long sum_time;
3449 long min_time;
3450 long max_time;
3451 long min_pid;
3452 long max_pid;
3453 cpumask_t cpus;
3454 nodemask_t nodes;
Christoph Lameter88a420e2007-05-06 14:49:45 -07003455};
3456
3457struct loc_track {
3458 unsigned long max;
3459 unsigned long count;
3460 struct location *loc;
3461};
3462
3463static void free_loc_track(struct loc_track *t)
3464{
3465 if (t->max)
3466 free_pages((unsigned long)t->loc,
3467 get_order(sizeof(struct location) * t->max));
3468}
3469
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003470static int alloc_loc_track(struct loc_track *t, unsigned long max, gfp_t flags)
Christoph Lameter88a420e2007-05-06 14:49:45 -07003471{
3472 struct location *l;
3473 int order;
3474
Christoph Lameter88a420e2007-05-06 14:49:45 -07003475 order = get_order(sizeof(struct location) * max);
3476
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003477 l = (void *)__get_free_pages(flags, order);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003478 if (!l)
3479 return 0;
3480
3481 if (t->count) {
3482 memcpy(l, t->loc, sizeof(struct location) * t->count);
3483 free_loc_track(t);
3484 }
3485 t->max = max;
3486 t->loc = l;
3487 return 1;
3488}
3489
3490static int add_location(struct loc_track *t, struct kmem_cache *s,
Christoph Lameter45edfa52007-05-09 02:32:45 -07003491 const struct track *track)
Christoph Lameter88a420e2007-05-06 14:49:45 -07003492{
3493 long start, end, pos;
3494 struct location *l;
3495 void *caddr;
Christoph Lameter45edfa52007-05-09 02:32:45 -07003496 unsigned long age = jiffies - track->when;
Christoph Lameter88a420e2007-05-06 14:49:45 -07003497
3498 start = -1;
3499 end = t->count;
3500
3501 for ( ; ; ) {
3502 pos = start + (end - start + 1) / 2;
3503
3504 /*
3505 * There is nothing at "end". If we end up there
3506 * we need to add something to before end.
3507 */
3508 if (pos == end)
3509 break;
3510
3511 caddr = t->loc[pos].addr;
Christoph Lameter45edfa52007-05-09 02:32:45 -07003512 if (track->addr == caddr) {
3513
3514 l = &t->loc[pos];
3515 l->count++;
3516 if (track->when) {
3517 l->sum_time += age;
3518 if (age < l->min_time)
3519 l->min_time = age;
3520 if (age > l->max_time)
3521 l->max_time = age;
3522
3523 if (track->pid < l->min_pid)
3524 l->min_pid = track->pid;
3525 if (track->pid > l->max_pid)
3526 l->max_pid = track->pid;
3527
3528 cpu_set(track->cpu, l->cpus);
3529 }
3530 node_set(page_to_nid(virt_to_page(track)), l->nodes);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003531 return 1;
3532 }
3533
Christoph Lameter45edfa52007-05-09 02:32:45 -07003534 if (track->addr < caddr)
Christoph Lameter88a420e2007-05-06 14:49:45 -07003535 end = pos;
3536 else
3537 start = pos;
3538 }
3539
3540 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07003541 * Not found. Insert new tracking element.
Christoph Lameter88a420e2007-05-06 14:49:45 -07003542 */
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003543 if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max, GFP_ATOMIC))
Christoph Lameter88a420e2007-05-06 14:49:45 -07003544 return 0;
3545
3546 l = t->loc + pos;
3547 if (pos < t->count)
3548 memmove(l + 1, l,
3549 (t->count - pos) * sizeof(struct location));
3550 t->count++;
3551 l->count = 1;
Christoph Lameter45edfa52007-05-09 02:32:45 -07003552 l->addr = track->addr;
3553 l->sum_time = age;
3554 l->min_time = age;
3555 l->max_time = age;
3556 l->min_pid = track->pid;
3557 l->max_pid = track->pid;
3558 cpus_clear(l->cpus);
3559 cpu_set(track->cpu, l->cpus);
3560 nodes_clear(l->nodes);
3561 node_set(page_to_nid(virt_to_page(track)), l->nodes);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003562 return 1;
3563}
3564
3565static void process_slab(struct loc_track *t, struct kmem_cache *s,
3566 struct page *page, enum track_item alloc)
3567{
Christoph Lametera973e9d2008-03-01 13:40:44 -08003568 void *addr = page_address(page);
Christoph Lameter39b26462008-04-14 19:11:30 +03003569 DECLARE_BITMAP(map, page->objects);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003570 void *p;
3571
Christoph Lameter39b26462008-04-14 19:11:30 +03003572 bitmap_zero(map, page->objects);
Christoph Lameter7656c722007-05-09 02:32:40 -07003573 for_each_free_object(p, s, page->freelist)
3574 set_bit(slab_index(p, s, addr), map);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003575
Christoph Lameter224a88b2008-04-14 19:11:31 +03003576 for_each_object(p, s, addr, page->objects)
Christoph Lameter45edfa52007-05-09 02:32:45 -07003577 if (!test_bit(slab_index(p, s, addr), map))
3578 add_location(t, s, get_track(s, p, alloc));
Christoph Lameter88a420e2007-05-06 14:49:45 -07003579}
3580
3581static int list_locations(struct kmem_cache *s, char *buf,
3582 enum track_item alloc)
3583{
Harvey Harrisone374d482008-01-31 15:20:50 -08003584 int len = 0;
Christoph Lameter88a420e2007-05-06 14:49:45 -07003585 unsigned long i;
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003586 struct loc_track t = { 0, 0, NULL };
Christoph Lameter88a420e2007-05-06 14:49:45 -07003587 int node;
3588
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003589 if (!alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location),
Andrew Mortonea3061d2007-10-16 01:26:09 -07003590 GFP_TEMPORARY))
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003591 return sprintf(buf, "Out of memory\n");
Christoph Lameter88a420e2007-05-06 14:49:45 -07003592
3593 /* Push back cpu slabs */
3594 flush_all(s);
3595
Christoph Lameterf64dc582007-10-16 01:25:33 -07003596 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter88a420e2007-05-06 14:49:45 -07003597 struct kmem_cache_node *n = get_node(s, node);
3598 unsigned long flags;
3599 struct page *page;
3600
Christoph Lameter9e869432007-08-22 14:01:56 -07003601 if (!atomic_long_read(&n->nr_slabs))
Christoph Lameter88a420e2007-05-06 14:49:45 -07003602 continue;
3603
3604 spin_lock_irqsave(&n->list_lock, flags);
3605 list_for_each_entry(page, &n->partial, lru)
3606 process_slab(&t, s, page, alloc);
3607 list_for_each_entry(page, &n->full, lru)
3608 process_slab(&t, s, page, alloc);
3609 spin_unlock_irqrestore(&n->list_lock, flags);
3610 }
3611
3612 for (i = 0; i < t.count; i++) {
Christoph Lameter45edfa52007-05-09 02:32:45 -07003613 struct location *l = &t.loc[i];
Christoph Lameter88a420e2007-05-06 14:49:45 -07003614
Harvey Harrisone374d482008-01-31 15:20:50 -08003615 if (len > PAGE_SIZE - 100)
Christoph Lameter88a420e2007-05-06 14:49:45 -07003616 break;
Harvey Harrisone374d482008-01-31 15:20:50 -08003617 len += sprintf(buf + len, "%7ld ", l->count);
Christoph Lameter45edfa52007-05-09 02:32:45 -07003618
3619 if (l->addr)
Harvey Harrisone374d482008-01-31 15:20:50 -08003620 len += sprint_symbol(buf + len, (unsigned long)l->addr);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003621 else
Harvey Harrisone374d482008-01-31 15:20:50 -08003622 len += sprintf(buf + len, "<not-available>");
Christoph Lameter45edfa52007-05-09 02:32:45 -07003623
3624 if (l->sum_time != l->min_time) {
Harvey Harrisone374d482008-01-31 15:20:50 -08003625 len += sprintf(buf + len, " age=%ld/%ld/%ld",
Roman Zippelf8bd2252008-05-01 04:34:31 -07003626 l->min_time,
3627 (long)div_u64(l->sum_time, l->count),
3628 l->max_time);
Christoph Lameter45edfa52007-05-09 02:32:45 -07003629 } else
Harvey Harrisone374d482008-01-31 15:20:50 -08003630 len += sprintf(buf + len, " age=%ld",
Christoph Lameter45edfa52007-05-09 02:32:45 -07003631 l->min_time);
3632
3633 if (l->min_pid != l->max_pid)
Harvey Harrisone374d482008-01-31 15:20:50 -08003634 len += sprintf(buf + len, " pid=%ld-%ld",
Christoph Lameter45edfa52007-05-09 02:32:45 -07003635 l->min_pid, l->max_pid);
3636 else
Harvey Harrisone374d482008-01-31 15:20:50 -08003637 len += sprintf(buf + len, " pid=%ld",
Christoph Lameter45edfa52007-05-09 02:32:45 -07003638 l->min_pid);
3639
Christoph Lameter84966342007-06-23 17:16:32 -07003640 if (num_online_cpus() > 1 && !cpus_empty(l->cpus) &&
Harvey Harrisone374d482008-01-31 15:20:50 -08003641 len < PAGE_SIZE - 60) {
3642 len += sprintf(buf + len, " cpus=");
3643 len += cpulist_scnprintf(buf + len, PAGE_SIZE - len - 50,
Christoph Lameter45edfa52007-05-09 02:32:45 -07003644 l->cpus);
3645 }
3646
Christoph Lameter84966342007-06-23 17:16:32 -07003647 if (num_online_nodes() > 1 && !nodes_empty(l->nodes) &&
Harvey Harrisone374d482008-01-31 15:20:50 -08003648 len < PAGE_SIZE - 60) {
3649 len += sprintf(buf + len, " nodes=");
3650 len += nodelist_scnprintf(buf + len, PAGE_SIZE - len - 50,
Christoph Lameter45edfa52007-05-09 02:32:45 -07003651 l->nodes);
3652 }
3653
Harvey Harrisone374d482008-01-31 15:20:50 -08003654 len += sprintf(buf + len, "\n");
Christoph Lameter88a420e2007-05-06 14:49:45 -07003655 }
3656
3657 free_loc_track(&t);
3658 if (!t.count)
Harvey Harrisone374d482008-01-31 15:20:50 -08003659 len += sprintf(buf, "No data\n");
3660 return len;
Christoph Lameter88a420e2007-05-06 14:49:45 -07003661}
3662
Christoph Lameter81819f02007-05-06 14:49:36 -07003663enum slab_stat_type {
Christoph Lameter205ab992008-04-14 19:11:40 +03003664 SL_ALL, /* All slabs */
3665 SL_PARTIAL, /* Only partially allocated slabs */
3666 SL_CPU, /* Only slabs used for cpu caches */
3667 SL_OBJECTS, /* Determine allocated objects not slabs */
3668 SL_TOTAL /* Determine object capacity not slabs */
Christoph Lameter81819f02007-05-06 14:49:36 -07003669};
3670
Christoph Lameter205ab992008-04-14 19:11:40 +03003671#define SO_ALL (1 << SL_ALL)
Christoph Lameter81819f02007-05-06 14:49:36 -07003672#define SO_PARTIAL (1 << SL_PARTIAL)
3673#define SO_CPU (1 << SL_CPU)
3674#define SO_OBJECTS (1 << SL_OBJECTS)
Christoph Lameter205ab992008-04-14 19:11:40 +03003675#define SO_TOTAL (1 << SL_TOTAL)
Christoph Lameter81819f02007-05-06 14:49:36 -07003676
Cyrill Gorcunov62e5c4b2008-03-02 23:28:24 +03003677static ssize_t show_slab_objects(struct kmem_cache *s,
3678 char *buf, unsigned long flags)
Christoph Lameter81819f02007-05-06 14:49:36 -07003679{
3680 unsigned long total = 0;
Christoph Lameter81819f02007-05-06 14:49:36 -07003681 int node;
3682 int x;
3683 unsigned long *nodes;
3684 unsigned long *per_cpu;
3685
3686 nodes = kzalloc(2 * sizeof(unsigned long) * nr_node_ids, GFP_KERNEL);
Cyrill Gorcunov62e5c4b2008-03-02 23:28:24 +03003687 if (!nodes)
3688 return -ENOMEM;
Christoph Lameter81819f02007-05-06 14:49:36 -07003689 per_cpu = nodes + nr_node_ids;
3690
Christoph Lameter205ab992008-04-14 19:11:40 +03003691 if (flags & SO_CPU) {
3692 int cpu;
Christoph Lameter81819f02007-05-06 14:49:36 -07003693
Christoph Lameter205ab992008-04-14 19:11:40 +03003694 for_each_possible_cpu(cpu) {
3695 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
Christoph Lameterdfb4f092007-10-16 01:26:05 -07003696
Christoph Lameter205ab992008-04-14 19:11:40 +03003697 if (!c || c->node < 0)
3698 continue;
3699
3700 if (c->page) {
3701 if (flags & SO_TOTAL)
3702 x = c->page->objects;
3703 else if (flags & SO_OBJECTS)
3704 x = c->page->inuse;
Christoph Lameter81819f02007-05-06 14:49:36 -07003705 else
3706 x = 1;
Christoph Lameter205ab992008-04-14 19:11:40 +03003707
Christoph Lameter81819f02007-05-06 14:49:36 -07003708 total += x;
Christoph Lameter205ab992008-04-14 19:11:40 +03003709 nodes[c->node] += x;
Christoph Lameter81819f02007-05-06 14:49:36 -07003710 }
Christoph Lameter205ab992008-04-14 19:11:40 +03003711 per_cpu[c->node]++;
Christoph Lameter81819f02007-05-06 14:49:36 -07003712 }
3713 }
3714
Christoph Lameter205ab992008-04-14 19:11:40 +03003715 if (flags & SO_ALL) {
3716 for_each_node_state(node, N_NORMAL_MEMORY) {
3717 struct kmem_cache_node *n = get_node(s, node);
Christoph Lameter81819f02007-05-06 14:49:36 -07003718
Christoph Lameter205ab992008-04-14 19:11:40 +03003719 if (flags & SO_TOTAL)
3720 x = atomic_long_read(&n->total_objects);
3721 else if (flags & SO_OBJECTS)
3722 x = atomic_long_read(&n->total_objects) -
3723 count_partial(n, count_free);
3724
3725 else
3726 x = atomic_long_read(&n->nr_slabs);
3727 total += x;
3728 nodes[node] += x;
3729 }
3730
3731 } else if (flags & SO_PARTIAL) {
3732 for_each_node_state(node, N_NORMAL_MEMORY) {
3733 struct kmem_cache_node *n = get_node(s, node);
3734
3735 if (flags & SO_TOTAL)
3736 x = count_partial(n, count_total);
3737 else if (flags & SO_OBJECTS)
3738 x = count_partial(n, count_inuse);
Christoph Lameter81819f02007-05-06 14:49:36 -07003739 else
3740 x = n->nr_partial;
3741 total += x;
3742 nodes[node] += x;
3743 }
Christoph Lameter81819f02007-05-06 14:49:36 -07003744 }
Christoph Lameter81819f02007-05-06 14:49:36 -07003745 x = sprintf(buf, "%lu", total);
3746#ifdef CONFIG_NUMA
Christoph Lameterf64dc582007-10-16 01:25:33 -07003747 for_each_node_state(node, N_NORMAL_MEMORY)
Christoph Lameter81819f02007-05-06 14:49:36 -07003748 if (nodes[node])
3749 x += sprintf(buf + x, " N%d=%lu",
3750 node, nodes[node]);
3751#endif
3752 kfree(nodes);
3753 return x + sprintf(buf + x, "\n");
3754}
3755
3756static int any_slab_objects(struct kmem_cache *s)
3757{
3758 int node;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07003759
3760 for_each_online_node(node) {
Christoph Lameter81819f02007-05-06 14:49:36 -07003761 struct kmem_cache_node *n = get_node(s, node);
3762
Christoph Lameterdfb4f092007-10-16 01:26:05 -07003763 if (!n)
3764 continue;
3765
Benjamin Herrenschmidt4ea33e22008-05-06 20:42:39 -07003766 if (atomic_long_read(&n->total_objects))
Christoph Lameter81819f02007-05-06 14:49:36 -07003767 return 1;
3768 }
3769 return 0;
3770}
3771
3772#define to_slab_attr(n) container_of(n, struct slab_attribute, attr)
3773#define to_slab(n) container_of(n, struct kmem_cache, kobj);
3774
3775struct slab_attribute {
3776 struct attribute attr;
3777 ssize_t (*show)(struct kmem_cache *s, char *buf);
3778 ssize_t (*store)(struct kmem_cache *s, const char *x, size_t count);
3779};
3780
3781#define SLAB_ATTR_RO(_name) \
3782 static struct slab_attribute _name##_attr = __ATTR_RO(_name)
3783
3784#define SLAB_ATTR(_name) \
3785 static struct slab_attribute _name##_attr = \
3786 __ATTR(_name, 0644, _name##_show, _name##_store)
3787
Christoph Lameter81819f02007-05-06 14:49:36 -07003788static ssize_t slab_size_show(struct kmem_cache *s, char *buf)
3789{
3790 return sprintf(buf, "%d\n", s->size);
3791}
3792SLAB_ATTR_RO(slab_size);
3793
3794static ssize_t align_show(struct kmem_cache *s, char *buf)
3795{
3796 return sprintf(buf, "%d\n", s->align);
3797}
3798SLAB_ATTR_RO(align);
3799
3800static ssize_t object_size_show(struct kmem_cache *s, char *buf)
3801{
3802 return sprintf(buf, "%d\n", s->objsize);
3803}
3804SLAB_ATTR_RO(object_size);
3805
3806static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf)
3807{
Christoph Lameter834f3d12008-04-14 19:11:31 +03003808 return sprintf(buf, "%d\n", oo_objects(s->oo));
Christoph Lameter81819f02007-05-06 14:49:36 -07003809}
3810SLAB_ATTR_RO(objs_per_slab);
3811
Christoph Lameter06b285d2008-04-14 19:11:41 +03003812static ssize_t order_store(struct kmem_cache *s,
3813 const char *buf, size_t length)
3814{
Christoph Lameter0121c6192008-04-29 16:11:12 -07003815 unsigned long order;
3816 int err;
3817
3818 err = strict_strtoul(buf, 10, &order);
3819 if (err)
3820 return err;
Christoph Lameter06b285d2008-04-14 19:11:41 +03003821
3822 if (order > slub_max_order || order < slub_min_order)
3823 return -EINVAL;
3824
3825 calculate_sizes(s, order);
3826 return length;
3827}
3828
Christoph Lameter81819f02007-05-06 14:49:36 -07003829static ssize_t order_show(struct kmem_cache *s, char *buf)
3830{
Christoph Lameter834f3d12008-04-14 19:11:31 +03003831 return sprintf(buf, "%d\n", oo_order(s->oo));
Christoph Lameter81819f02007-05-06 14:49:36 -07003832}
Christoph Lameter06b285d2008-04-14 19:11:41 +03003833SLAB_ATTR(order);
Christoph Lameter81819f02007-05-06 14:49:36 -07003834
3835static ssize_t ctor_show(struct kmem_cache *s, char *buf)
3836{
3837 if (s->ctor) {
3838 int n = sprint_symbol(buf, (unsigned long)s->ctor);
3839
3840 return n + sprintf(buf + n, "\n");
3841 }
3842 return 0;
3843}
3844SLAB_ATTR_RO(ctor);
3845
Christoph Lameter81819f02007-05-06 14:49:36 -07003846static ssize_t aliases_show(struct kmem_cache *s, char *buf)
3847{
3848 return sprintf(buf, "%d\n", s->refcount - 1);
3849}
3850SLAB_ATTR_RO(aliases);
3851
3852static ssize_t slabs_show(struct kmem_cache *s, char *buf)
3853{
Christoph Lameter205ab992008-04-14 19:11:40 +03003854 return show_slab_objects(s, buf, SO_ALL);
Christoph Lameter81819f02007-05-06 14:49:36 -07003855}
3856SLAB_ATTR_RO(slabs);
3857
3858static ssize_t partial_show(struct kmem_cache *s, char *buf)
3859{
Christoph Lameterd9acf4b2008-02-15 15:22:21 -08003860 return show_slab_objects(s, buf, SO_PARTIAL);
Christoph Lameter81819f02007-05-06 14:49:36 -07003861}
3862SLAB_ATTR_RO(partial);
3863
3864static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf)
3865{
Christoph Lameterd9acf4b2008-02-15 15:22:21 -08003866 return show_slab_objects(s, buf, SO_CPU);
Christoph Lameter81819f02007-05-06 14:49:36 -07003867}
3868SLAB_ATTR_RO(cpu_slabs);
3869
3870static ssize_t objects_show(struct kmem_cache *s, char *buf)
3871{
Christoph Lameter205ab992008-04-14 19:11:40 +03003872 return show_slab_objects(s, buf, SO_ALL|SO_OBJECTS);
Christoph Lameter81819f02007-05-06 14:49:36 -07003873}
3874SLAB_ATTR_RO(objects);
3875
Christoph Lameter205ab992008-04-14 19:11:40 +03003876static ssize_t objects_partial_show(struct kmem_cache *s, char *buf)
3877{
3878 return show_slab_objects(s, buf, SO_PARTIAL|SO_OBJECTS);
3879}
3880SLAB_ATTR_RO(objects_partial);
3881
3882static ssize_t total_objects_show(struct kmem_cache *s, char *buf)
3883{
3884 return show_slab_objects(s, buf, SO_ALL|SO_TOTAL);
3885}
3886SLAB_ATTR_RO(total_objects);
3887
Christoph Lameter81819f02007-05-06 14:49:36 -07003888static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf)
3889{
3890 return sprintf(buf, "%d\n", !!(s->flags & SLAB_DEBUG_FREE));
3891}
3892
3893static ssize_t sanity_checks_store(struct kmem_cache *s,
3894 const char *buf, size_t length)
3895{
3896 s->flags &= ~SLAB_DEBUG_FREE;
3897 if (buf[0] == '1')
3898 s->flags |= SLAB_DEBUG_FREE;
3899 return length;
3900}
3901SLAB_ATTR(sanity_checks);
3902
3903static ssize_t trace_show(struct kmem_cache *s, char *buf)
3904{
3905 return sprintf(buf, "%d\n", !!(s->flags & SLAB_TRACE));
3906}
3907
3908static ssize_t trace_store(struct kmem_cache *s, const char *buf,
3909 size_t length)
3910{
3911 s->flags &= ~SLAB_TRACE;
3912 if (buf[0] == '1')
3913 s->flags |= SLAB_TRACE;
3914 return length;
3915}
3916SLAB_ATTR(trace);
3917
3918static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf)
3919{
3920 return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT));
3921}
3922
3923static ssize_t reclaim_account_store(struct kmem_cache *s,
3924 const char *buf, size_t length)
3925{
3926 s->flags &= ~SLAB_RECLAIM_ACCOUNT;
3927 if (buf[0] == '1')
3928 s->flags |= SLAB_RECLAIM_ACCOUNT;
3929 return length;
3930}
3931SLAB_ATTR(reclaim_account);
3932
3933static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf)
3934{
Christoph Lameter5af60832007-05-06 14:49:56 -07003935 return sprintf(buf, "%d\n", !!(s->flags & SLAB_HWCACHE_ALIGN));
Christoph Lameter81819f02007-05-06 14:49:36 -07003936}
3937SLAB_ATTR_RO(hwcache_align);
3938
3939#ifdef CONFIG_ZONE_DMA
3940static ssize_t cache_dma_show(struct kmem_cache *s, char *buf)
3941{
3942 return sprintf(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA));
3943}
3944SLAB_ATTR_RO(cache_dma);
3945#endif
3946
3947static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf)
3948{
3949 return sprintf(buf, "%d\n", !!(s->flags & SLAB_DESTROY_BY_RCU));
3950}
3951SLAB_ATTR_RO(destroy_by_rcu);
3952
3953static ssize_t red_zone_show(struct kmem_cache *s, char *buf)
3954{
3955 return sprintf(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE));
3956}
3957
3958static ssize_t red_zone_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_RED_ZONE;
3965 if (buf[0] == '1')
3966 s->flags |= SLAB_RED_ZONE;
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(red_zone);
3971
3972static ssize_t poison_show(struct kmem_cache *s, char *buf)
3973{
3974 return sprintf(buf, "%d\n", !!(s->flags & SLAB_POISON));
3975}
3976
3977static ssize_t poison_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_POISON;
3984 if (buf[0] == '1')
3985 s->flags |= SLAB_POISON;
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(poison);
3990
3991static ssize_t store_user_show(struct kmem_cache *s, char *buf)
3992{
3993 return sprintf(buf, "%d\n", !!(s->flags & SLAB_STORE_USER));
3994}
3995
3996static ssize_t store_user_store(struct kmem_cache *s,
3997 const char *buf, size_t length)
3998{
3999 if (any_slab_objects(s))
4000 return -EBUSY;
4001
4002 s->flags &= ~SLAB_STORE_USER;
4003 if (buf[0] == '1')
4004 s->flags |= SLAB_STORE_USER;
Christoph Lameter06b285d2008-04-14 19:11:41 +03004005 calculate_sizes(s, -1);
Christoph Lameter81819f02007-05-06 14:49:36 -07004006 return length;
4007}
4008SLAB_ATTR(store_user);
4009
Christoph Lameter53e15af2007-05-06 14:49:43 -07004010static ssize_t validate_show(struct kmem_cache *s, char *buf)
4011{
4012 return 0;
4013}
4014
4015static ssize_t validate_store(struct kmem_cache *s,
4016 const char *buf, size_t length)
4017{
Christoph Lameter434e2452007-07-17 04:03:30 -07004018 int ret = -EINVAL;
4019
4020 if (buf[0] == '1') {
4021 ret = validate_slab_cache(s);
4022 if (ret >= 0)
4023 ret = length;
4024 }
4025 return ret;
Christoph Lameter53e15af2007-05-06 14:49:43 -07004026}
4027SLAB_ATTR(validate);
4028
Christoph Lameter2086d262007-05-06 14:49:46 -07004029static ssize_t shrink_show(struct kmem_cache *s, char *buf)
4030{
4031 return 0;
4032}
4033
4034static ssize_t shrink_store(struct kmem_cache *s,
4035 const char *buf, size_t length)
4036{
4037 if (buf[0] == '1') {
4038 int rc = kmem_cache_shrink(s);
4039
4040 if (rc)
4041 return rc;
4042 } else
4043 return -EINVAL;
4044 return length;
4045}
4046SLAB_ATTR(shrink);
4047
Christoph Lameter88a420e2007-05-06 14:49:45 -07004048static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf)
4049{
4050 if (!(s->flags & SLAB_STORE_USER))
4051 return -ENOSYS;
4052 return list_locations(s, buf, TRACK_ALLOC);
4053}
4054SLAB_ATTR_RO(alloc_calls);
4055
4056static ssize_t free_calls_show(struct kmem_cache *s, char *buf)
4057{
4058 if (!(s->flags & SLAB_STORE_USER))
4059 return -ENOSYS;
4060 return list_locations(s, buf, TRACK_FREE);
4061}
4062SLAB_ATTR_RO(free_calls);
4063
Christoph Lameter81819f02007-05-06 14:49:36 -07004064#ifdef CONFIG_NUMA
Christoph Lameter98246012008-01-07 23:20:26 -08004065static ssize_t remote_node_defrag_ratio_show(struct kmem_cache *s, char *buf)
Christoph Lameter81819f02007-05-06 14:49:36 -07004066{
Christoph Lameter98246012008-01-07 23:20:26 -08004067 return sprintf(buf, "%d\n", s->remote_node_defrag_ratio / 10);
Christoph Lameter81819f02007-05-06 14:49:36 -07004068}
4069
Christoph Lameter98246012008-01-07 23:20:26 -08004070static ssize_t remote_node_defrag_ratio_store(struct kmem_cache *s,
Christoph Lameter81819f02007-05-06 14:49:36 -07004071 const char *buf, size_t length)
4072{
Christoph Lameter0121c6192008-04-29 16:11:12 -07004073 unsigned long ratio;
4074 int err;
Christoph Lameter81819f02007-05-06 14:49:36 -07004075
Christoph Lameter0121c6192008-04-29 16:11:12 -07004076 err = strict_strtoul(buf, 10, &ratio);
4077 if (err)
4078 return err;
4079
4080 if (ratio < 100)
4081 s->remote_node_defrag_ratio = ratio * 10;
4082
Christoph Lameter81819f02007-05-06 14:49:36 -07004083 return length;
4084}
Christoph Lameter98246012008-01-07 23:20:26 -08004085SLAB_ATTR(remote_node_defrag_ratio);
Christoph Lameter81819f02007-05-06 14:49:36 -07004086#endif
4087
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004088#ifdef CONFIG_SLUB_STATS
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004089static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si)
4090{
4091 unsigned long sum = 0;
4092 int cpu;
4093 int len;
4094 int *data = kmalloc(nr_cpu_ids * sizeof(int), GFP_KERNEL);
4095
4096 if (!data)
4097 return -ENOMEM;
4098
4099 for_each_online_cpu(cpu) {
4100 unsigned x = get_cpu_slab(s, cpu)->stat[si];
4101
4102 data[cpu] = x;
4103 sum += x;
4104 }
4105
4106 len = sprintf(buf, "%lu", sum);
4107
Christoph Lameter50ef37b2008-04-14 18:52:05 +03004108#ifdef CONFIG_SMP
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004109 for_each_online_cpu(cpu) {
4110 if (data[cpu] && len < PAGE_SIZE - 20)
Christoph Lameter50ef37b2008-04-14 18:52:05 +03004111 len += sprintf(buf + len, " C%d=%u", cpu, data[cpu]);
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004112 }
Christoph Lameter50ef37b2008-04-14 18:52:05 +03004113#endif
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004114 kfree(data);
4115 return len + sprintf(buf + len, "\n");
4116}
4117
4118#define STAT_ATTR(si, text) \
4119static ssize_t text##_show(struct kmem_cache *s, char *buf) \
4120{ \
4121 return show_stat(s, buf, si); \
4122} \
4123SLAB_ATTR_RO(text); \
4124
4125STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath);
4126STAT_ATTR(ALLOC_SLOWPATH, alloc_slowpath);
4127STAT_ATTR(FREE_FASTPATH, free_fastpath);
4128STAT_ATTR(FREE_SLOWPATH, free_slowpath);
4129STAT_ATTR(FREE_FROZEN, free_frozen);
4130STAT_ATTR(FREE_ADD_PARTIAL, free_add_partial);
4131STAT_ATTR(FREE_REMOVE_PARTIAL, free_remove_partial);
4132STAT_ATTR(ALLOC_FROM_PARTIAL, alloc_from_partial);
4133STAT_ATTR(ALLOC_SLAB, alloc_slab);
4134STAT_ATTR(ALLOC_REFILL, alloc_refill);
4135STAT_ATTR(FREE_SLAB, free_slab);
4136STAT_ATTR(CPUSLAB_FLUSH, cpuslab_flush);
4137STAT_ATTR(DEACTIVATE_FULL, deactivate_full);
4138STAT_ATTR(DEACTIVATE_EMPTY, deactivate_empty);
4139STAT_ATTR(DEACTIVATE_TO_HEAD, deactivate_to_head);
4140STAT_ATTR(DEACTIVATE_TO_TAIL, deactivate_to_tail);
4141STAT_ATTR(DEACTIVATE_REMOTE_FREES, deactivate_remote_frees);
Christoph Lameter65c33762008-04-14 19:11:40 +03004142STAT_ATTR(ORDER_FALLBACK, order_fallback);
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004143#endif
4144
Pekka Enberg06428782008-01-07 23:20:27 -08004145static struct attribute *slab_attrs[] = {
Christoph Lameter81819f02007-05-06 14:49:36 -07004146 &slab_size_attr.attr,
4147 &object_size_attr.attr,
4148 &objs_per_slab_attr.attr,
4149 &order_attr.attr,
4150 &objects_attr.attr,
Christoph Lameter205ab992008-04-14 19:11:40 +03004151 &objects_partial_attr.attr,
4152 &total_objects_attr.attr,
Christoph Lameter81819f02007-05-06 14:49:36 -07004153 &slabs_attr.attr,
4154 &partial_attr.attr,
4155 &cpu_slabs_attr.attr,
4156 &ctor_attr.attr,
Christoph Lameter81819f02007-05-06 14:49:36 -07004157 &aliases_attr.attr,
4158 &align_attr.attr,
4159 &sanity_checks_attr.attr,
4160 &trace_attr.attr,
4161 &hwcache_align_attr.attr,
4162 &reclaim_account_attr.attr,
4163 &destroy_by_rcu_attr.attr,
4164 &red_zone_attr.attr,
4165 &poison_attr.attr,
4166 &store_user_attr.attr,
Christoph Lameter53e15af2007-05-06 14:49:43 -07004167 &validate_attr.attr,
Christoph Lameter2086d262007-05-06 14:49:46 -07004168 &shrink_attr.attr,
Christoph Lameter88a420e2007-05-06 14:49:45 -07004169 &alloc_calls_attr.attr,
4170 &free_calls_attr.attr,
Christoph Lameter81819f02007-05-06 14:49:36 -07004171#ifdef CONFIG_ZONE_DMA
4172 &cache_dma_attr.attr,
4173#endif
4174#ifdef CONFIG_NUMA
Christoph Lameter98246012008-01-07 23:20:26 -08004175 &remote_node_defrag_ratio_attr.attr,
Christoph Lameter81819f02007-05-06 14:49:36 -07004176#endif
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004177#ifdef CONFIG_SLUB_STATS
4178 &alloc_fastpath_attr.attr,
4179 &alloc_slowpath_attr.attr,
4180 &free_fastpath_attr.attr,
4181 &free_slowpath_attr.attr,
4182 &free_frozen_attr.attr,
4183 &free_add_partial_attr.attr,
4184 &free_remove_partial_attr.attr,
4185 &alloc_from_partial_attr.attr,
4186 &alloc_slab_attr.attr,
4187 &alloc_refill_attr.attr,
4188 &free_slab_attr.attr,
4189 &cpuslab_flush_attr.attr,
4190 &deactivate_full_attr.attr,
4191 &deactivate_empty_attr.attr,
4192 &deactivate_to_head_attr.attr,
4193 &deactivate_to_tail_attr.attr,
4194 &deactivate_remote_frees_attr.attr,
Christoph Lameter65c33762008-04-14 19:11:40 +03004195 &order_fallback_attr.attr,
Christoph Lameter8ff12cf2008-02-07 17:47:41 -08004196#endif
Christoph Lameter81819f02007-05-06 14:49:36 -07004197 NULL
4198};
4199
4200static struct attribute_group slab_attr_group = {
4201 .attrs = slab_attrs,
4202};
4203
4204static ssize_t slab_attr_show(struct kobject *kobj,
4205 struct attribute *attr,
4206 char *buf)
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->show)
4216 return -EIO;
4217
4218 err = attribute->show(s, buf);
4219
4220 return err;
4221}
4222
4223static ssize_t slab_attr_store(struct kobject *kobj,
4224 struct attribute *attr,
4225 const char *buf, size_t len)
4226{
4227 struct slab_attribute *attribute;
4228 struct kmem_cache *s;
4229 int err;
4230
4231 attribute = to_slab_attr(attr);
4232 s = to_slab(kobj);
4233
4234 if (!attribute->store)
4235 return -EIO;
4236
4237 err = attribute->store(s, buf, len);
4238
4239 return err;
4240}
4241
Christoph Lameter151c6022008-01-07 22:29:05 -08004242static void kmem_cache_release(struct kobject *kobj)
4243{
4244 struct kmem_cache *s = to_slab(kobj);
4245
4246 kfree(s);
4247}
4248
Christoph Lameter81819f02007-05-06 14:49:36 -07004249static struct sysfs_ops slab_sysfs_ops = {
4250 .show = slab_attr_show,
4251 .store = slab_attr_store,
4252};
4253
4254static struct kobj_type slab_ktype = {
4255 .sysfs_ops = &slab_sysfs_ops,
Christoph Lameter151c6022008-01-07 22:29:05 -08004256 .release = kmem_cache_release
Christoph Lameter81819f02007-05-06 14:49:36 -07004257};
4258
4259static int uevent_filter(struct kset *kset, struct kobject *kobj)
4260{
4261 struct kobj_type *ktype = get_ktype(kobj);
4262
4263 if (ktype == &slab_ktype)
4264 return 1;
4265 return 0;
4266}
4267
4268static struct kset_uevent_ops slab_uevent_ops = {
4269 .filter = uevent_filter,
4270};
4271
Greg Kroah-Hartman27c3a312007-11-01 09:29:06 -06004272static struct kset *slab_kset;
Christoph Lameter81819f02007-05-06 14:49:36 -07004273
4274#define ID_STR_LENGTH 64
4275
4276/* Create a unique string id for a slab cache:
Christoph Lameter6446faa2008-02-15 23:45:26 -08004277 *
4278 * Format :[flags-]size
Christoph Lameter81819f02007-05-06 14:49:36 -07004279 */
4280static char *create_unique_id(struct kmem_cache *s)
4281{
4282 char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL);
4283 char *p = name;
4284
4285 BUG_ON(!name);
4286
4287 *p++ = ':';
4288 /*
4289 * First flags affecting slabcache operations. We will only
4290 * get here for aliasable slabs so we do not need to support
4291 * too many flags. The flags here must cover all flags that
4292 * are matched during merging to guarantee that the id is
4293 * unique.
4294 */
4295 if (s->flags & SLAB_CACHE_DMA)
4296 *p++ = 'd';
4297 if (s->flags & SLAB_RECLAIM_ACCOUNT)
4298 *p++ = 'a';
4299 if (s->flags & SLAB_DEBUG_FREE)
4300 *p++ = 'F';
4301 if (p != name + 1)
4302 *p++ = '-';
4303 p += sprintf(p, "%07d", s->size);
4304 BUG_ON(p > name + ID_STR_LENGTH - 1);
4305 return name;
4306}
4307
4308static int sysfs_slab_add(struct kmem_cache *s)
4309{
4310 int err;
4311 const char *name;
4312 int unmergeable;
4313
4314 if (slab_state < SYSFS)
4315 /* Defer until later */
4316 return 0;
4317
4318 unmergeable = slab_unmergeable(s);
4319 if (unmergeable) {
4320 /*
4321 * Slabcache can never be merged so we can use the name proper.
4322 * This is typically the case for debug situations. In that
4323 * case we can catch duplicate names easily.
4324 */
Greg Kroah-Hartman27c3a312007-11-01 09:29:06 -06004325 sysfs_remove_link(&slab_kset->kobj, s->name);
Christoph Lameter81819f02007-05-06 14:49:36 -07004326 name = s->name;
4327 } else {
4328 /*
4329 * Create a unique name for the slab as a target
4330 * for the symlinks.
4331 */
4332 name = create_unique_id(s);
4333 }
4334
Greg Kroah-Hartman27c3a312007-11-01 09:29:06 -06004335 s->kobj.kset = slab_kset;
Greg Kroah-Hartman1eada112007-12-17 23:05:35 -07004336 err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, name);
4337 if (err) {
4338 kobject_put(&s->kobj);
Christoph Lameter81819f02007-05-06 14:49:36 -07004339 return err;
Greg Kroah-Hartman1eada112007-12-17 23:05:35 -07004340 }
Christoph Lameter81819f02007-05-06 14:49:36 -07004341
4342 err = sysfs_create_group(&s->kobj, &slab_attr_group);
4343 if (err)
4344 return err;
4345 kobject_uevent(&s->kobj, KOBJ_ADD);
4346 if (!unmergeable) {
4347 /* Setup first alias */
4348 sysfs_slab_alias(s, s->name);
4349 kfree(name);
4350 }
4351 return 0;
4352}
4353
4354static void sysfs_slab_remove(struct kmem_cache *s)
4355{
4356 kobject_uevent(&s->kobj, KOBJ_REMOVE);
4357 kobject_del(&s->kobj);
Christoph Lameter151c6022008-01-07 22:29:05 -08004358 kobject_put(&s->kobj);
Christoph Lameter81819f02007-05-06 14:49:36 -07004359}
4360
4361/*
4362 * Need to buffer aliases during bootup until sysfs becomes
4363 * available lest we loose that information.
4364 */
4365struct saved_alias {
4366 struct kmem_cache *s;
4367 const char *name;
4368 struct saved_alias *next;
4369};
4370
Adrian Bunk5af328a2007-07-17 04:03:27 -07004371static struct saved_alias *alias_list;
Christoph Lameter81819f02007-05-06 14:49:36 -07004372
4373static int sysfs_slab_alias(struct kmem_cache *s, const char *name)
4374{
4375 struct saved_alias *al;
4376
4377 if (slab_state == SYSFS) {
4378 /*
4379 * If we have a leftover link then remove it.
4380 */
Greg Kroah-Hartman27c3a312007-11-01 09:29:06 -06004381 sysfs_remove_link(&slab_kset->kobj, name);
4382 return sysfs_create_link(&slab_kset->kobj, &s->kobj, name);
Christoph Lameter81819f02007-05-06 14:49:36 -07004383 }
4384
4385 al = kmalloc(sizeof(struct saved_alias), GFP_KERNEL);
4386 if (!al)
4387 return -ENOMEM;
4388
4389 al->s = s;
4390 al->name = name;
4391 al->next = alias_list;
4392 alias_list = al;
4393 return 0;
4394}
4395
4396static int __init slab_sysfs_init(void)
4397{
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07004398 struct kmem_cache *s;
Christoph Lameter81819f02007-05-06 14:49:36 -07004399 int err;
4400
Greg Kroah-Hartman0ff21e42007-11-06 10:36:58 -08004401 slab_kset = kset_create_and_add("slab", &slab_uevent_ops, kernel_kobj);
Greg Kroah-Hartman27c3a312007-11-01 09:29:06 -06004402 if (!slab_kset) {
Christoph Lameter81819f02007-05-06 14:49:36 -07004403 printk(KERN_ERR "Cannot register slab subsystem.\n");
4404 return -ENOSYS;
4405 }
4406
Christoph Lameter26a7bd02007-05-09 02:32:39 -07004407 slab_state = SYSFS;
4408
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07004409 list_for_each_entry(s, &slab_caches, list) {
Christoph Lameter26a7bd02007-05-09 02:32:39 -07004410 err = sysfs_slab_add(s);
Christoph Lameter5d540fb2007-08-30 23:56:26 -07004411 if (err)
4412 printk(KERN_ERR "SLUB: Unable to add boot slab %s"
4413 " to sysfs\n", s->name);
Christoph Lameter26a7bd02007-05-09 02:32:39 -07004414 }
Christoph Lameter81819f02007-05-06 14:49:36 -07004415
4416 while (alias_list) {
4417 struct saved_alias *al = alias_list;
4418
4419 alias_list = alias_list->next;
4420 err = sysfs_slab_alias(al->s, al->name);
Christoph Lameter5d540fb2007-08-30 23:56:26 -07004421 if (err)
4422 printk(KERN_ERR "SLUB: Unable to add boot slab alias"
4423 " %s to sysfs\n", s->name);
Christoph Lameter81819f02007-05-06 14:49:36 -07004424 kfree(al);
4425 }
4426
4427 resiliency_test();
4428 return 0;
4429}
4430
4431__initcall(slab_sysfs_init);
Christoph Lameter81819f02007-05-06 14:49:36 -07004432#endif
Pekka J Enberg57ed3ed2008-01-01 17:23:28 +01004433
4434/*
4435 * The /proc/slabinfo ABI
4436 */
Linus Torvalds158a9622008-01-02 13:04:48 -08004437#ifdef CONFIG_SLABINFO
4438
Christoph Lameter0121c6192008-04-29 16:11:12 -07004439ssize_t slabinfo_write(struct file *file, const char __user *buffer,
4440 size_t count, loff_t *ppos)
Linus Torvalds158a9622008-01-02 13:04:48 -08004441{
4442 return -EINVAL;
4443}
4444
Pekka J Enberg57ed3ed2008-01-01 17:23:28 +01004445
4446static void print_slabinfo_header(struct seq_file *m)
4447{
4448 seq_puts(m, "slabinfo - version: 2.1\n");
4449 seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
4450 "<objperslab> <pagesperslab>");
4451 seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
4452 seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
4453 seq_putc(m, '\n');
4454}
4455
4456static void *s_start(struct seq_file *m, loff_t *pos)
4457{
4458 loff_t n = *pos;
4459
4460 down_read(&slub_lock);
4461 if (!n)
4462 print_slabinfo_header(m);
4463
4464 return seq_list_start(&slab_caches, *pos);
4465}
4466
4467static void *s_next(struct seq_file *m, void *p, loff_t *pos)
4468{
4469 return seq_list_next(p, &slab_caches, pos);
4470}
4471
4472static void s_stop(struct seq_file *m, void *p)
4473{
4474 up_read(&slub_lock);
4475}
4476
4477static int s_show(struct seq_file *m, void *p)
4478{
4479 unsigned long nr_partials = 0;
4480 unsigned long nr_slabs = 0;
4481 unsigned long nr_inuse = 0;
Christoph Lameter205ab992008-04-14 19:11:40 +03004482 unsigned long nr_objs = 0;
4483 unsigned long nr_free = 0;
Pekka J Enberg57ed3ed2008-01-01 17:23:28 +01004484 struct kmem_cache *s;
4485 int node;
4486
4487 s = list_entry(p, struct kmem_cache, list);
4488
4489 for_each_online_node(node) {
4490 struct kmem_cache_node *n = get_node(s, node);
4491
4492 if (!n)
4493 continue;
4494
4495 nr_partials += n->nr_partial;
4496 nr_slabs += atomic_long_read(&n->nr_slabs);
Christoph Lameter205ab992008-04-14 19:11:40 +03004497 nr_objs += atomic_long_read(&n->total_objects);
4498 nr_free += count_partial(n, count_free);
Pekka J Enberg57ed3ed2008-01-01 17:23:28 +01004499 }
4500
Christoph Lameter205ab992008-04-14 19:11:40 +03004501 nr_inuse = nr_objs - nr_free;
Pekka J Enberg57ed3ed2008-01-01 17:23:28 +01004502
4503 seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", s->name, nr_inuse,
Christoph Lameter834f3d12008-04-14 19:11:31 +03004504 nr_objs, s->size, oo_objects(s->oo),
4505 (1 << oo_order(s->oo)));
Pekka J Enberg57ed3ed2008-01-01 17:23:28 +01004506 seq_printf(m, " : tunables %4u %4u %4u", 0, 0, 0);
4507 seq_printf(m, " : slabdata %6lu %6lu %6lu", nr_slabs, nr_slabs,
4508 0UL);
4509 seq_putc(m, '\n');
4510 return 0;
4511}
4512
4513const struct seq_operations slabinfo_op = {
4514 .start = s_start,
4515 .next = s_next,
4516 .stop = s_stop,
4517 .show = s_show,
4518};
4519
Linus Torvalds158a9622008-01-02 13:04:48 -08004520#endif /* CONFIG_SLABINFO */