mm/slob.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * SLOB Allocator: Simple List Of Blocks
   4  *
   5  * Matt Mackall <mpm@selenic.com> 12/30/03
   6  *
   7  * NUMA support by Paul Mundt, 2007.
   8  *
   9  * How SLOB works:
  10  *
  11  * The core of SLOB is a traditional K&R style heap allocator, with
  12  * support for returning aligned objects. The granularity of this
  13  * allocator is as little as 2 bytes, however typically most architectures
  14  * will require 4 bytes on 32-bit and 8 bytes on 64-bit.
  15  *
  16  * The slob heap is a set of linked list of pages from alloc_pages(),
  17  * and within each page, there is a singly-linked list of free blocks
  18  * (slob_t). The heap is grown on demand. To reduce fragmentation,
  19  * heap pages are segregated into three lists, with objects less than
  20  * 256 bytes, objects less than 1024 bytes, and all other objects.
  21  *
  22  * Allocation from heap involves first searching for a page with
  23  * sufficient free blocks (using a next-fit-like approach) followed by
  24  * a first-fit scan of the page. Deallocation inserts objects back
  25  * into the free list in address order, so this is effectively an
  26  * address-ordered first fit.
  27  *
  28  * Above this is an implementation of kmalloc/kfree. Blocks returned
  29  * from kmalloc are prepended with a 4-byte header with the kmalloc size.
  30  * If kmalloc is asked for objects of PAGE_SIZE or larger, it calls
  31  * alloc_pages() directly, allocating compound pages so the page order
  32  * does not have to be separately tracked.
  33  * These objects are detected in kfree() because PageSlab()
  34  * is false for them.
  35  *
  36  * SLAB is emulated on top of SLOB by simply calling constructors and
  37  * destructors for every SLAB allocation. Objects are returned with the
  38  * 4-byte alignment unless the SLAB_HWCACHE_ALIGN flag is set, in which
  39  * case the low-level allocator will fragment blocks to create the proper
  40  * alignment. Again, objects of page-size or greater are allocated by
  41  * calling alloc_pages(). As SLAB objects know their size, no separate
  42  * size bookkeeping is necessary and there is essentially no allocation
  43  * space overhead, and compound pages aren't needed for multi-page
  44  * allocations.
  45  *
  46  * NUMA support in SLOB is fairly simplistic, pushing most of the real
  47  * logic down to the page allocator, and simply doing the node accounting
  48  * on the upper levels. In the event that a node id is explicitly
  49  * provided, __alloc_pages_node() with the specified node id is used
  50  * instead. The common case (or when the node id isn't explicitly provided)
  51  * will default to the current node, as per numa_node_id().
  52  *
  53  * Node aware pages are still inserted in to the global freelist, and
  54  * these are scanned for by matching against the node id encoded in the
  55  * page flags. As a result, block allocations that can be satisfied from
  56  * the freelist will only be done so on pages residing on the same node,
  57  * in order to prevent random node placement.
  58  */
  59
  60 #include <linux/kernel.h>
  61 #include <linux/slab.h>
  62
  63 #include <linux/mm.h>
  64 #include <linux/swap.h> /* struct reclaim_state */
  65 #include <linux/cache.h>
  66 #include <linux/init.h>
  67 #include <linux/export.h>
  68 #include <linux/rcupdate.h>
  69 #include <linux/list.h>
  70 #include <linux/kmemleak.h>
  71
  72 #include <trace/events/kmem.h>
  73
  74 #include <linux/atomic.h>
  75
  76 #include "slab.h"
  77 /*
  78  * slob_block has a field 'units', which indicates size of block if +ve,
  79  * or offset of next block if -ve (in SLOB_UNITs).
  80  *
  81  * Free blocks of size 1 unit simply contain the offset of the next block.
  82  * Those with larger size contain their size in the first SLOB_UNIT of
  83  * memory, and the offset of the next free block in the second SLOB_UNIT.
  84  */
  85 #if PAGE_SIZE <= (32767 * 2)
  86 typedef s16 slobidx_t;
  87 #else
  88 typedef s32 slobidx_t;
  89 #endif
  90
  91 struct slob_block {
  92         slobidx_t units;
  93 };
  94 typedef struct slob_block slob_t;
  95
  96 /*
  97  * All partially free slob pages go on these lists.
  98  */
  99 #define SLOB_BREAK1 256
 100 #define SLOB_BREAK2 1024
 101 static LIST_HEAD(free_slob_small);
 102 static LIST_HEAD(free_slob_medium);
 103 static LIST_HEAD(free_slob_large);
 104
 105 /*
 106  * slob_page_free: true for pages on free_slob_pages list.
 107  */
 108 static inline int slob_page_free(struct page *sp)
 109 {
 110         return PageSlobFree(sp);
 111 }
 112
 113 static void set_slob_page_free(struct page *sp, struct list_head *list)
 114 {
 115         list_add(&sp->slab_list, list);
 116         __SetPageSlobFree(sp);
 117 }
 118
 119 static inline void clear_slob_page_free(struct page *sp)
 120 {
 121         list_del(&sp->slab_list);
 122         __ClearPageSlobFree(sp);
 123 }
 124
 125 #define SLOB_UNIT sizeof(slob_t)
 126 #define SLOB_UNITS(size) DIV_ROUND_UP(size, SLOB_UNIT)
 127
 128 /*
 129  * struct slob_rcu is inserted at the tail of allocated slob blocks, which
 130  * were created with a SLAB_TYPESAFE_BY_RCU slab. slob_rcu is used to free
 131  * the block using call_rcu.
 132  */
 133 struct slob_rcu {
 134         struct rcu_head head;
 135         int size;
 136 };
 137
 138 /*
 139  * slob_lock protects all slob allocator structures.
 140  */
 141 static DEFINE_SPINLOCK(slob_lock);
 142
 143 /*
 144  * Encode the given size and next info into a free slob block s.
 145  */
 146 static void set_slob(slob_t *s, slobidx_t size, slob_t *next)
 147 {
 148         slob_t *base = (slob_t *)((unsigned long)s & PAGE_MASK);
 149         slobidx_t offset = next - base;
 150
 151         if (size > 1) {
 152                 s[0].units = size;
 153                 s[1].units = offset;
 154         } else
 155                 s[0].units = -offset;
 156 }
 157
 158 /*
 159  * Return the size of a slob block.
 160  */
 161 static slobidx_t slob_units(slob_t *s)
 162 {
 163         if (s->units > 0)
 164                 return s->units;
 165         return 1;
 166 }
 167
 168 /*
 169  * Return the next free slob block pointer after this one.
 170  */
 171 static slob_t *slob_next(slob_t *s)
 172 {
 173         slob_t *base = (slob_t *)((unsigned long)s & PAGE_MASK);
 174         slobidx_t next;
 175
 176         if (s[0].units < 0)
 177                 next = -s[0].units;
 178         else
 179                 next = s[1].units;
 180         return base+next;
 181 }
 182
 183 /*
 184  * Returns true if s is the last free block in its page.
 185  */
 186 static int slob_last(slob_t *s)
 187 {
 188         return !((unsigned long)slob_next(s) & ~PAGE_MASK);
 189 }
 190
 191 static void *slob_new_pages(gfp_t gfp, int order, int node)
 192 {
 193         void *page;
 194
 195 #ifdef CONFIG_NUMA
 196         if (node != NUMA_NO_NODE)
 197                 page = __alloc_pages_node(node, gfp, order);
 198         else
 199 #endif
 200                 page = alloc_pages(gfp, order);
 201
 202         if (!page)
 203                 return NULL;
 204
 205         return page_address(page);
 206 }
 207
 208 static void slob_free_pages(void *b, int order)
 209 {
 210         if (current->reclaim_state)
 211                 current->reclaim_state->reclaimed_slab += 1 << order;
 212         free_pages((unsigned long)b, order);
 213 }
 214
 215 /*
 216  * slob_page_alloc() - Allocate a slob block within a given slob_page sp.
 217  * @sp: Page to look in.
 218  * @size: Size of the allocation.
 219  * @align: Allocation alignment.
 220  * @page_removed_from_list: Return parameter.
 221  *
 222  * Tries to find a chunk of memory at least @size bytes big within @page.
 223  *
 224  * Return: Pointer to memory if allocated, %NULL otherwise.  If the
 225  *         allocation fills up @page then the page is removed from the
 226  *         freelist, in this case @page_removed_from_list will be set to
 227  *         true (set to false otherwise).
 228  */
 229 static void *slob_page_alloc(struct page *sp, size_t size, int align,
 230                              bool *page_removed_from_list)
 231 {
 232         slob_t *prev, *cur, *aligned = NULL;
 233         int delta = 0, units = SLOB_UNITS(size);
 234
 235         *page_removed_from_list = false;
 236         for (prev = NULL, cur = sp->freelist; ; prev = cur, cur = slob_next(cur)) {
 237                 slobidx_t avail = slob_units(cur);
 238
 239                 if (align) {
 240                         aligned = (slob_t *)ALIGN((unsigned long)cur, align);
 241                         delta = aligned - cur;
 242                 }
 243                 if (avail >= units + delta) { /* room enough? */
 244                         slob_t *next;
 245
 246                         if (delta) { /* need to fragment head to align? */
 247                                 next = slob_next(cur);
 248                                 set_slob(aligned, avail - delta, next);
 249                                 set_slob(cur, delta, aligned);
 250                                 prev = cur;
 251                                 cur = aligned;
 252                                 avail = slob_units(cur);
 253                         }
 254
 255                         next = slob_next(cur);
 256                         if (avail == units) { /* exact fit? unlink. */
 257                                 if (prev)
 258                                         set_slob(prev, slob_units(prev), next);
 259                                 else
 260                                         sp->freelist = next;
 261                         } else { /* fragment */
 262                                 if (prev)
 263                                         set_slob(prev, slob_units(prev), cur + units);
 264                                 else
 265                                         sp->freelist = cur + units;
 266                                 set_slob(cur + units, avail - units, next);
 267                         }
 268
 269                         sp->units -= units;
 270                         if (!sp->units) {
 271                                 clear_slob_page_free(sp);
 272                                 *page_removed_from_list = true;
 273                         }
 274                         return cur;
 275                 }
 276                 if (slob_last(cur))
 277                         return NULL;
 278         }
 279 }
 280
 281 /*
 282  * slob_alloc: entry point into the slob allocator.
 283  */
 284 static void *slob_alloc(size_t size, gfp_t gfp, int align, int node)
 285 {
 286         struct page *sp;
 287         struct list_head *slob_list;
 288         slob_t *b = NULL;
 289         unsigned long flags;
 290         bool _unused;
 291
 292         if (size < SLOB_BREAK1)
 293                 slob_list = &free_slob_small;
 294         else if (size < SLOB_BREAK2)
 295                 slob_list = &free_slob_medium;
 296         else
 297                 slob_list = &free_slob_large;
 298
 299         spin_lock_irqsave(&slob_lock, flags);
 300         /* Iterate through each partially free page, try to find room */
 301         list_for_each_entry(sp, slob_list, slab_list) {
 302                 bool page_removed_from_list = false;
 303 #ifdef CONFIG_NUMA
 304                 /*
 305                  * If there's a node specification, search for a partial
 306                  * page with a matching node id in the freelist.
 307                  */
 308                 if (node != NUMA_NO_NODE && page_to_nid(sp) != node)
 309                         continue;
 310 #endif
 311                 /* Enough room on this page? */
 312                 if (sp->units < SLOB_UNITS(size))
 313                         continue;
 314
 315                 b = slob_page_alloc(sp, size, align, &page_removed_from_list);
 316                 if (!b)
 317                         continue;
 318
 319                 /*
 320                  * If slob_page_alloc() removed sp from the list then we
 321                  * cannot call list functions on sp.  If so allocation
 322                  * did not fragment the page anyway so optimisation is
 323                  * unnecessary.
 324                  */
 325                 if (!page_removed_from_list) {
 326                         /*
 327                          * Improve fragment distribution and reduce our average
 328                          * search time by starting our next search here. (see
 329                          * Knuth vol 1, sec 2.5, pg 449)
 330                          */
 331                         if (!list_is_first(&sp->slab_list, slob_list))
 332                                 list_rotate_to_front(&sp->slab_list, slob_list);
 333                 }
 334                 break;
 335         }
 336         spin_unlock_irqrestore(&slob_lock, flags);
 337
 338         /* Not enough space: must allocate a new page */
 339         if (!b) {
 340                 b = slob_new_pages(gfp & ~__GFP_ZERO, 0, node);
 341                 if (!b)
 342                         return NULL;
 343                 sp = virt_to_page(b);
 344                 __SetPageSlab(sp);
 345
 346                 spin_lock_irqsave(&slob_lock, flags);
 347                 sp->units = SLOB_UNITS(PAGE_SIZE);
 348                 sp->freelist = b;
 349                 INIT_LIST_HEAD(&sp->slab_list);
 350                 set_slob(b, SLOB_UNITS(PAGE_SIZE), b + SLOB_UNITS(PAGE_SIZE));
 351                 set_slob_page_free(sp, slob_list);
 352                 b = slob_page_alloc(sp, size, align, &_unused);
 353                 BUG_ON(!b);
 354                 spin_unlock_irqrestore(&slob_lock, flags);
 355         }
 356         if (unlikely(gfp & __GFP_ZERO))
 357                 memset(b, 0, size);
 358         return b;
 359 }
 360
 361 /*
 362  * slob_free: entry point into the slob allocator.
 363  */
 364 static void slob_free(void *block, int size)
 365 {
 366         struct page *sp;
 367         slob_t *prev, *next, *b = (slob_t *)block;
 368         slobidx_t units;
 369         unsigned long flags;
 370         struct list_head *slob_list;
 371
 372         if (unlikely(ZERO_OR_NULL_PTR(block)))
 373                 return;
 374         BUG_ON(!size);
 375
 376         sp = virt_to_page(block);
 377         units = SLOB_UNITS(size);
 378
 379         spin_lock_irqsave(&slob_lock, flags);
 380
 381         if (sp->units + units == SLOB_UNITS(PAGE_SIZE)) {
 382                 /* Go directly to page allocator. Do not pass slob allocator */
 383                 if (slob_page_free(sp))
 384                         clear_slob_page_free(sp);
 385                 spin_unlock_irqrestore(&slob_lock, flags);
 386                 __ClearPageSlab(sp);
 387                 page_mapcount_reset(sp);
 388                 slob_free_pages(b, 0);
 389                 return;
 390         }
 391
 392         if (!slob_page_free(sp)) {
 393                 /* This slob page is about to become partially free. Easy! */
 394                 sp->units = units;
 395                 sp->freelist = b;
 396                 set_slob(b, units,
 397                         (void *)((unsigned long)(b +
 398                                         SLOB_UNITS(PAGE_SIZE)) & PAGE_MASK));
 399                 if (size < SLOB_BREAK1)
 400                         slob_list = &free_slob_small;
 401                 else if (size < SLOB_BREAK2)
 402                         slob_list = &free_slob_medium;
 403                 else
 404                         slob_list = &free_slob_large;
 405                 set_slob_page_free(sp, slob_list);
 406                 goto out;
 407         }
 408
 409         /*
 410          * Otherwise the page is already partially free, so find reinsertion
 411          * point.
 412          */
 413         sp->units += units;
 414
 415         if (b < (slob_t *)sp->freelist) {
 416                 if (b + units == sp->freelist) {
 417                         units += slob_units(sp->freelist);
 418                         sp->freelist = slob_next(sp->freelist);
 419                 }
 420                 set_slob(b, units, sp->freelist);
 421                 sp->freelist = b;
 422         } else {
 423                 prev = sp->freelist;
 424                 next = slob_next(prev);
 425                 while (b > next) {
 426                         prev = next;
 427                         next = slob_next(prev);
 428                 }
 429
 430                 if (!slob_last(prev) && b + units == next) {
 431                         units += slob_units(next);
 432                         set_slob(b, units, slob_next(next));
 433                 } else
 434                         set_slob(b, units, next);
 435
 436                 if (prev + slob_units(prev) == b) {
 437                         units = slob_units(b) + slob_units(prev);
 438                         set_slob(prev, units, slob_next(b));
 439                 } else
 440                         set_slob(prev, slob_units(prev), b);
 441         }
 442 out:
 443         spin_unlock_irqrestore(&slob_lock, flags);
 444 }
 445
 446 /*
 447  * End of slob allocator proper. Begin kmem_cache_alloc and kmalloc frontend.
 448  */
 449
 450 static __always_inline void *
 451 __do_kmalloc_node(size_t size, gfp_t gfp, int node, unsigned long caller)
 452 {
 453         unsigned int *m;
 454         int align = max_t(size_t, ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN);
 455         void *ret;
 456
 457         gfp &= gfp_allowed_mask;
 458
 459         fs_reclaim_acquire(gfp);
 460         fs_reclaim_release(gfp);
 461
 462         if (size < PAGE_SIZE - align) {
 463                 if (!size)
 464                         return ZERO_SIZE_PTR;
 465
 466                 m = slob_alloc(size + align, gfp, align, node);
 467
 468                 if (!m)
 469                         return NULL;
 470                 *m = size;
 471                 ret = (void *)m + align;
 472
 473                 trace_kmalloc_node(caller, ret,
 474                                    size, size + align, gfp, node);
 475         } else {
 476                 unsigned int order = get_order(size);
 477
 478                 if (likely(order))
 479                         gfp |= __GFP_COMP;
 480                 ret = slob_new_pages(gfp, order, node);
 481
 482                 trace_kmalloc_node(caller, ret,
 483                                    size, PAGE_SIZE << order, gfp, node);
 484         }
 485
 486         kmemleak_alloc(ret, size, 1, gfp);
 487         return ret;
 488 }
 489
 490 void *__kmalloc(size_t size, gfp_t gfp)
 491 {
 492         return __do_kmalloc_node(size, gfp, NUMA_NO_NODE, _RET_IP_);
 493 }
 494 EXPORT_SYMBOL(__kmalloc);
 495
 496 void *__kmalloc_track_caller(size_t size, gfp_t gfp, unsigned long caller)
 497 {
 498         return __do_kmalloc_node(size, gfp, NUMA_NO_NODE, caller);
 499 }
 500
 501 #ifdef CONFIG_NUMA
 502 void *__kmalloc_node_track_caller(size_t size, gfp_t gfp,
 503                                         int node, unsigned long caller)
 504 {
 505         return __do_kmalloc_node(size, gfp, node, caller);
 506 }
 507 #endif
 508
 509 void kfree(const void *block)
 510 {
 511         struct page *sp;
 512
 513         trace_kfree(_RET_IP_, block);
 514
 515         if (unlikely(ZERO_OR_NULL_PTR(block)))
 516                 return;
 517         kmemleak_free(block);
 518
 519         sp = virt_to_page(block);
 520         if (PageSlab(sp)) {
 521                 int align = max_t(size_t, ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN);
 522                 unsigned int *m = (unsigned int *)(block - align);
 523                 slob_free(m, *m + align);
 524         } else
 525                 __free_pages(sp, compound_order(sp));
 526 }
 527 EXPORT_SYMBOL(kfree);
 528
 529 /* can't use ksize for kmem_cache_alloc memory, only kmalloc */
 530 size_t __ksize(const void *block)
 531 {
 532         struct page *sp;
 533         int align;
 534         unsigned int *m;
 535
 536         BUG_ON(!block);
 537         if (unlikely(block == ZERO_SIZE_PTR))
 538                 return 0;
 539
 540         sp = virt_to_page(block);
 541         if (unlikely(!PageSlab(sp)))
 542                 return PAGE_SIZE << compound_order(sp);
 543
 544         align = max_t(size_t, ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN);
 545         m = (unsigned int *)(block - align);
 546         return SLOB_UNITS(*m) * SLOB_UNIT;
 547 }
 548 EXPORT_SYMBOL(__ksize);
 549
 550 int __kmem_cache_create(struct kmem_cache *c, slab_flags_t flags)
 551 {
 552         if (flags & SLAB_TYPESAFE_BY_RCU) {
 553                 /* leave room for rcu footer at the end of object */
 554                 c->size += sizeof(struct slob_rcu);
 555         }
 556         c->flags = flags;
 557         return 0;
 558 }
 559
 560 static void *slob_alloc_node(struct kmem_cache *c, gfp_t flags, int node)
 561 {
 562         void *b;
 563
 564         flags &= gfp_allowed_mask;
 565
 566         fs_reclaim_acquire(flags);
 567         fs_reclaim_release(flags);
 568
 569         if (c->size < PAGE_SIZE) {
 570                 b = slob_alloc(c->size, flags, c->align, node);
 571                 trace_kmem_cache_alloc_node(_RET_IP_, b, c->object_size,
 572                                             SLOB_UNITS(c->size) * SLOB_UNIT,
 573                                             flags, node);
 574         } else {
 575                 b = slob_new_pages(flags, get_order(c->size), node);
 576                 trace_kmem_cache_alloc_node(_RET_IP_, b, c->object_size,
 577                                             PAGE_SIZE << get_order(c->size),
 578                                             flags, node);
 579         }
 580
 581         if (b && c->ctor) {
 582                 WARN_ON_ONCE(flags & __GFP_ZERO);
 583                 c->ctor(b);
 584         }
 585
 586         kmemleak_alloc_recursive(b, c->size, 1, c->flags, flags);
 587         return b;
 588 }
 589
 590 void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
 591 {
 592         return slob_alloc_node(cachep, flags, NUMA_NO_NODE);
 593 }
 594 EXPORT_SYMBOL(kmem_cache_alloc);
 595
 596 #ifdef CONFIG_NUMA
 597 void *__kmalloc_node(size_t size, gfp_t gfp, int node)
 598 {
 599         return __do_kmalloc_node(size, gfp, node, _RET_IP_);
 600 }
 601 EXPORT_SYMBOL(__kmalloc_node);
 602
 603 void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t gfp, int node)
 604 {
 605         return slob_alloc_node(cachep, gfp, node);
 606 }
 607 EXPORT_SYMBOL(kmem_cache_alloc_node);
 608 #endif
 609
 610 static void __kmem_cache_free(void *b, int size)
 611 {
 612         if (size < PAGE_SIZE)
 613                 slob_free(b, size);
 614         else
 615                 slob_free_pages(b, get_order(size));
 616 }
 617
 618 static void kmem_rcu_free(struct rcu_head *head)
 619 {
 620         struct slob_rcu *slob_rcu = (struct slob_rcu *)head;
 621         void *b = (void *)slob_rcu - (slob_rcu->size - sizeof(struct slob_rcu));
 622
 623         __kmem_cache_free(b, slob_rcu->size);
 624 }
 625
 626 void kmem_cache_free(struct kmem_cache *c, void *b)
 627 {
 628         kmemleak_free_recursive(b, c->flags);
 629         if (unlikely(c->flags & SLAB_TYPESAFE_BY_RCU)) {
 630                 struct slob_rcu *slob_rcu;
 631                 slob_rcu = b + (c->size - sizeof(struct slob_rcu));
 632                 slob_rcu->size = c->size;
 633                 call_rcu(&slob_rcu->head, kmem_rcu_free);
 634         } else {
 635                 __kmem_cache_free(b, c->size);
 636         }
 637
 638         trace_kmem_cache_free(_RET_IP_, b);
 639 }
 640 EXPORT_SYMBOL(kmem_cache_free);
 641
 642 void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p)
 643 {
 644         __kmem_cache_free_bulk(s, size, p);
 645 }
 646 EXPORT_SYMBOL(kmem_cache_free_bulk);
 647
 648 int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
 649                                                                 void **p)
 650 {
 651         return __kmem_cache_alloc_bulk(s, flags, size, p);
 652 }
 653 EXPORT_SYMBOL(kmem_cache_alloc_bulk);
 654
 655 int __kmem_cache_shutdown(struct kmem_cache *c)
 656 {
 657         /* No way to check for remaining objects */
 658         return 0;
 659 }
 660
 661 void __kmem_cache_release(struct kmem_cache *c)
 662 {
 663 }
 664
 665 int __kmem_cache_shrink(struct kmem_cache *d)
 666 {
 667         return 0;
 668 }
 669
 670 struct kmem_cache kmem_cache_boot = {
 671         .name = "kmem_cache",
 672         .size = sizeof(struct kmem_cache),
 673         .flags = SLAB_PANIC,
 674         .align = ARCH_KMALLOC_MINALIGN,
 675 };
 676
 677 void __init kmem_cache_init(void)
 678 {
 679         kmem_cache = &kmem_cache_boot;
 680         slab_state = UP;
 681 }
 682
 683 void __init kmem_cache_init_late(void)
 684 {
 685         slab_state = FULL;
 686 }