Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
page_alloc.c
Go to the documentation of this file.
1 /*
2  * linux/mm/page_alloc.c
3  *
4  * Manages the free list, the system allocates free pages here.
5  * Note that kmalloc() lives in slab.c
6  *
7  * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
8  * Swap reorganised 29.12.95, Stephen Tweedie
9  * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
10  * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
11  * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
12  * Zone balancing, Kanoj Sarcar, SGI, Jan 2000
13  * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
14  * (lots of bits borrowed from Ingo Molnar & Andrew Morton)
15  */
16 
17 #include <linux/stddef.h>
18 #include <linux/mm.h>
19 #include <linux/swap.h>
20 #include <linux/interrupt.h>
21 #include <linux/pagemap.h>
22 #include <linux/jiffies.h>
23 #include <linux/bootmem.h>
24 #include <linux/memblock.h>
25 #include <linux/compiler.h>
26 #include <linux/kernel.h>
27 #include <linux/kmemcheck.h>
28 #include <linux/module.h>
29 #include <linux/suspend.h>
30 #include <linux/pagevec.h>
31 #include <linux/blkdev.h>
32 #include <linux/slab.h>
33 #include <linux/ratelimit.h>
34 #include <linux/oom.h>
35 #include <linux/notifier.h>
36 #include <linux/topology.h>
37 #include <linux/sysctl.h>
38 #include <linux/cpu.h>
39 #include <linux/cpuset.h>
40 #include <linux/memory_hotplug.h>
41 #include <linux/nodemask.h>
42 #include <linux/vmalloc.h>
43 #include <linux/vmstat.h>
44 #include <linux/mempolicy.h>
45 #include <linux/stop_machine.h>
46 #include <linux/sort.h>
47 #include <linux/pfn.h>
48 #include <linux/backing-dev.h>
49 #include <linux/fault-inject.h>
50 #include <linux/page-isolation.h>
51 #include <linux/page_cgroup.h>
52 #include <linux/debugobjects.h>
53 #include <linux/kmemleak.h>
54 #include <linux/compaction.h>
55 #include <trace/events/kmem.h>
56 #include <linux/ftrace_event.h>
57 #include <linux/memcontrol.h>
58 #include <linux/prefetch.h>
59 #include <linux/migrate.h>
60 #include <linux/page-debug-flags.h>
61 
62 #include <asm/tlbflush.h>
63 #include <asm/div64.h>
64 #include "internal.h"
65 
66 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
67 DEFINE_PER_CPU(int, numa_node);
68 EXPORT_PER_CPU_SYMBOL(numa_node);
69 #endif
70 
71 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
72 /*
73  * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
74  * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
75  * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
76  * defined in <linux/topology.h>.
77  */
78 DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */
79 EXPORT_PER_CPU_SYMBOL(_numa_mem_);
80 #endif
81 
82 /*
83  * Array of node states.
84  */
87  [N_ONLINE] = { { [0] = 1UL } },
88 #ifndef CONFIG_NUMA
89  [N_NORMAL_MEMORY] = { { [0] = 1UL } },
90 #ifdef CONFIG_HIGHMEM
91  [N_HIGH_MEMORY] = { { [0] = 1UL } },
92 #endif
93  [N_CPU] = { { [0] = 1UL } },
94 #endif /* NUMA */
95 };
97 
98 unsigned long totalram_pages __read_mostly;
99 unsigned long totalreserve_pages __read_mostly;
100 /*
101  * When calculating the number of globally allowed dirty pages, there
102  * is a certain number of per-zone reserves that should not be
103  * considered dirtyable memory. This is the sum of those reserves
104  * over all existing zones that contribute dirtyable memory.
105  */
106 unsigned long dirty_balance_reserve __read_mostly;
107 
110 
111 #ifdef CONFIG_PM_SLEEP
112 /*
113  * The following functions are used by the suspend/hibernate code to temporarily
114  * change gfp_allowed_mask in order to avoid using I/O during memory allocations
115  * while devices are suspended. To avoid races with the suspend/hibernate code,
116  * they should always be called with pm_mutex held (gfp_allowed_mask also should
117  * only be modified with pm_mutex held, unless the suspend/hibernate code is
118  * guaranteed not to run in parallel with that modification).
119  */
120 
121 static gfp_t saved_gfp_mask;
122 
123 void pm_restore_gfp_mask(void)
124 {
125  WARN_ON(!mutex_is_locked(&pm_mutex));
126  if (saved_gfp_mask) {
127  gfp_allowed_mask = saved_gfp_mask;
128  saved_gfp_mask = 0;
129  }
130 }
131 
132 void pm_restrict_gfp_mask(void)
133 {
134  WARN_ON(!mutex_is_locked(&pm_mutex));
135  WARN_ON(saved_gfp_mask);
136  saved_gfp_mask = gfp_allowed_mask;
138 }
139 
140 bool pm_suspended_storage(void)
141 {
142  if ((gfp_allowed_mask & GFP_IOFS) == GFP_IOFS)
143  return false;
144  return true;
145 }
146 #endif /* CONFIG_PM_SLEEP */
147 
148 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
150 #endif
151 
152 static void __free_pages_ok(struct page *page, unsigned int order);
153 
154 /*
155  * results with 256, 32 in the lowmem_reserve sysctl:
156  * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
157  * 1G machine -> (16M dma, 784M normal, 224M high)
158  * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
159  * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
160  * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
161  *
162  * TBD: should special case ZONE_DMA32 machines here - in those we normally
163  * don't need any ZONE_NORMAL reservation
164  */
165 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
166 #ifdef CONFIG_ZONE_DMA
167  256,
168 #endif
169 #ifdef CONFIG_ZONE_DMA32
170  256,
171 #endif
172 #ifdef CONFIG_HIGHMEM
173  32,
174 #endif
175  32,
176 };
177 
178 EXPORT_SYMBOL(totalram_pages);
179 
180 static char * const zone_names[MAX_NR_ZONES] = {
181 #ifdef CONFIG_ZONE_DMA
182  "DMA",
183 #endif
184 #ifdef CONFIG_ZONE_DMA32
185  "DMA32",
186 #endif
187  "Normal",
188 #ifdef CONFIG_HIGHMEM
189  "HighMem",
190 #endif
191  "Movable",
192 };
193 
194 int min_free_kbytes = 1024;
195 
196 static unsigned long __meminitdata nr_kernel_pages;
197 static unsigned long __meminitdata nr_all_pages;
198 static unsigned long __meminitdata dma_reserve;
199 
200 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
201 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
202 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
203 static unsigned long __initdata required_kernelcore;
204 static unsigned long __initdata required_movablecore;
205 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
206 
207 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
208 int movable_zone;
209 EXPORT_SYMBOL(movable_zone);
210 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
211 
212 #if MAX_NUMNODES > 1
213 int nr_node_ids __read_mostly = MAX_NUMNODES;
214 int nr_online_nodes __read_mostly = 1;
217 #endif
218 
220 
221 /*
222  * NOTE:
223  * Don't use set_pageblock_migratetype(page, MIGRATE_ISOLATE) directly.
224  * Instead, use {un}set_pageblock_isolate.
225  */
226 void set_pageblock_migratetype(struct page *page, int migratetype)
227 {
228 
230  migratetype = MIGRATE_UNMOVABLE;
231 
232  set_pageblock_flags_group(page, (unsigned long)migratetype,
234 }
235 
237 
238 #ifdef CONFIG_DEBUG_VM
239 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
240 {
241  int ret = 0;
242  unsigned seq;
243  unsigned long pfn = page_to_pfn(page);
244 
245  do {
246  seq = zone_span_seqbegin(zone);
247  if (pfn >= zone->zone_start_pfn + zone->spanned_pages)
248  ret = 1;
249  else if (pfn < zone->zone_start_pfn)
250  ret = 1;
251  } while (zone_span_seqretry(zone, seq));
252 
253  return ret;
254 }
255 
256 static int page_is_consistent(struct zone *zone, struct page *page)
257 {
258  if (!pfn_valid_within(page_to_pfn(page)))
259  return 0;
260  if (zone != page_zone(page))
261  return 0;
262 
263  return 1;
264 }
265 /*
266  * Temporary debugging check for pages not lying within a given zone.
267  */
268 static int bad_range(struct zone *zone, struct page *page)
269 {
270  if (page_outside_zone_boundaries(zone, page))
271  return 1;
272  if (!page_is_consistent(zone, page))
273  return 1;
274 
275  return 0;
276 }
277 #else
278 static inline int bad_range(struct zone *zone, struct page *page)
279 {
280  return 0;
281 }
282 #endif
283 
284 static void bad_page(struct page *page)
285 {
286  static unsigned long resume;
287  static unsigned long nr_shown;
288  static unsigned long nr_unshown;
289 
290  /* Don't complain about poisoned pages */
291  if (PageHWPoison(page)) {
292  reset_page_mapcount(page); /* remove PageBuddy */
293  return;
294  }
295 
296  /*
297  * Allow a burst of 60 reports, then keep quiet for that minute;
298  * or allow a steady drip of one report per second.
299  */
300  if (nr_shown == 60) {
301  if (time_before(jiffies, resume)) {
302  nr_unshown++;
303  goto out;
304  }
305  if (nr_unshown) {
307  "BUG: Bad page state: %lu messages suppressed\n",
308  nr_unshown);
309  nr_unshown = 0;
310  }
311  nr_shown = 0;
312  }
313  if (nr_shown++ == 0)
314  resume = jiffies + 60 * HZ;
315 
316  printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n",
317  current->comm, page_to_pfn(page));
318  dump_page(page);
319 
320  print_modules();
321  dump_stack();
322 out:
323  /* Leave bad fields for debug, except PageBuddy could make trouble */
324  reset_page_mapcount(page); /* remove PageBuddy */
326 }
327 
328 /*
329  * Higher-order pages are called "compound pages". They are structured thusly:
330  *
331  * The first PAGE_SIZE page is called the "head page".
332  *
333  * The remaining PAGE_SIZE pages are called "tail pages".
334  *
335  * All pages have PG_compound set. All tail pages have their ->first_page
336  * pointing at the head page.
337  *
338  * The first tail page's ->lru.next holds the address of the compound page's
339  * put_page() function. Its ->lru.prev holds the order of allocation.
340  * This usage means that zero-order pages may not be compound.
341  */
342 
343 static void free_compound_page(struct page *page)
344 {
345  __free_pages_ok(page, compound_order(page));
346 }
347 
348 void prep_compound_page(struct page *page, unsigned long order)
349 {
350  int i;
351  int nr_pages = 1 << order;
352 
353  set_compound_page_dtor(page, free_compound_page);
354  set_compound_order(page, order);
355  __SetPageHead(page);
356  for (i = 1; i < nr_pages; i++) {
357  struct page *p = page + i;
358  __SetPageTail(p);
359  set_page_count(p, 0);
360  p->first_page = page;
361  }
362 }
363 
364 /* update __split_huge_page_refcount if you change this function */
365 static int destroy_compound_page(struct page *page, unsigned long order)
366 {
367  int i;
368  int nr_pages = 1 << order;
369  int bad = 0;
370 
371  if (unlikely(compound_order(page) != order) ||
372  unlikely(!PageHead(page))) {
373  bad_page(page);
374  bad++;
375  }
376 
377  __ClearPageHead(page);
378 
379  for (i = 1; i < nr_pages; i++) {
380  struct page *p = page + i;
381 
382  if (unlikely(!PageTail(p) || (p->first_page != page))) {
383  bad_page(page);
384  bad++;
385  }
386  __ClearPageTail(p);
387  }
388 
389  return bad;
390 }
391 
392 static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
393 {
394  int i;
395 
396  /*
397  * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
398  * and __GFP_HIGHMEM from hard or soft interrupt context.
399  */
400  VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt());
401  for (i = 0; i < (1 << order); i++)
402  clear_highpage(page + i);
403 }
404 
405 #ifdef CONFIG_DEBUG_PAGEALLOC
406 unsigned int _debug_guardpage_minorder;
407 
408 static int __init debug_guardpage_minorder_setup(char *buf)
409 {
410  unsigned long res;
411 
412  if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
413  printk(KERN_ERR "Bad debug_guardpage_minorder value\n");
414  return 0;
415  }
416  _debug_guardpage_minorder = res;
417  printk(KERN_INFO "Setting debug_guardpage_minorder to %lu\n", res);
418  return 0;
419 }
420 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup);
421 
422 static inline void set_page_guard_flag(struct page *page)
423 {
424  __set_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
425 }
426 
427 static inline void clear_page_guard_flag(struct page *page)
428 {
429  __clear_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
430 }
431 #else
432 static inline void set_page_guard_flag(struct page *page) { }
433 static inline void clear_page_guard_flag(struct page *page) { }
434 #endif
435 
436 static inline void set_page_order(struct page *page, int order)
437 {
438  set_page_private(page, order);
439  __SetPageBuddy(page);
440 }
441 
442 static inline void rmv_page_order(struct page *page)
443 {
444  __ClearPageBuddy(page);
445  set_page_private(page, 0);
446 }
447 
448 /*
449  * Locate the struct page for both the matching buddy in our
450  * pair (buddy1) and the combined O(n+1) page they form (page).
451  *
452  * 1) Any buddy B1 will have an order O twin B2 which satisfies
453  * the following equation:
454  * B2 = B1 ^ (1 << O)
455  * For example, if the starting buddy (buddy2) is #8 its order
456  * 1 buddy is #10:
457  * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
458  *
459  * 2) Any buddy B will have an order O+1 parent P which
460  * satisfies the following equation:
461  * P = B & ~(1 << O)
462  *
463  * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
464  */
465 static inline unsigned long
466 __find_buddy_index(unsigned long page_idx, unsigned int order)
467 {
468  return page_idx ^ (1 << order);
469 }
470 
471 /*
472  * This function checks whether a page is free && is the buddy
473  * we can do coalesce a page and its buddy if
474  * (a) the buddy is not in a hole &&
475  * (b) the buddy is in the buddy system &&
476  * (c) a page and its buddy have the same order &&
477  * (d) a page and its buddy are in the same zone.
478  *
479  * For recording whether a page is in the buddy system, we set ->_mapcount -2.
480  * Setting, clearing, and testing _mapcount -2 is serialized by zone->lock.
481  *
482  * For recording page's order, we use page_private(page).
483  */
484 static inline int page_is_buddy(struct page *page, struct page *buddy,
485  int order)
486 {
487  if (!pfn_valid_within(page_to_pfn(buddy)))
488  return 0;
489 
490  if (page_zone_id(page) != page_zone_id(buddy))
491  return 0;
492 
493  if (page_is_guard(buddy) && page_order(buddy) == order) {
494  VM_BUG_ON(page_count(buddy) != 0);
495  return 1;
496  }
497 
498  if (PageBuddy(buddy) && page_order(buddy) == order) {
499  VM_BUG_ON(page_count(buddy) != 0);
500  return 1;
501  }
502  return 0;
503 }
504 
505 /*
506  * Freeing function for a buddy system allocator.
507  *
508  * The concept of a buddy system is to maintain direct-mapped table
509  * (containing bit values) for memory blocks of various "orders".
510  * The bottom level table contains the map for the smallest allocatable
511  * units of memory (here, pages), and each level above it describes
512  * pairs of units from the levels below, hence, "buddies".
513  * At a high level, all that happens here is marking the table entry
514  * at the bottom level available, and propagating the changes upward
515  * as necessary, plus some accounting needed to play nicely with other
516  * parts of the VM system.
517  * At each level, we keep a list of pages, which are heads of continuous
518  * free pages of length of (1 << order) and marked with _mapcount -2. Page's
519  * order is recorded in page_private(page) field.
520  * So when we are allocating or freeing one, we can derive the state of the
521  * other. That is, if we allocate a small block, and both were
522  * free, the remainder of the region must be split into blocks.
523  * If a block is freed, and its buddy is also free, then this
524  * triggers coalescing into a block of larger size.
525  *
526  * -- wli
527  */
528 
529 static inline void __free_one_page(struct page *page,
530  struct zone *zone, unsigned int order,
531  int migratetype)
532 {
533  unsigned long page_idx;
534  unsigned long combined_idx;
535  unsigned long uninitialized_var(buddy_idx);
536  struct page *buddy;
537 
538  if (unlikely(PageCompound(page)))
539  if (unlikely(destroy_compound_page(page, order)))
540  return;
541 
542  VM_BUG_ON(migratetype == -1);
543 
544  page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
545 
546  VM_BUG_ON(page_idx & ((1 << order) - 1));
547  VM_BUG_ON(bad_range(zone, page));
548 
549  while (order < MAX_ORDER-1) {
550  buddy_idx = __find_buddy_index(page_idx, order);
551  buddy = page + (buddy_idx - page_idx);
552  if (!page_is_buddy(page, buddy, order))
553  break;
554  /*
555  * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
556  * merge with it and move up one order.
557  */
558  if (page_is_guard(buddy)) {
559  clear_page_guard_flag(buddy);
560  set_page_private(page, 0);
561  __mod_zone_freepage_state(zone, 1 << order,
562  migratetype);
563  } else {
564  list_del(&buddy->lru);
565  zone->free_area[order].nr_free--;
566  rmv_page_order(buddy);
567  }
568  combined_idx = buddy_idx & page_idx;
569  page = page + (combined_idx - page_idx);
570  page_idx = combined_idx;
571  order++;
572  }
573  set_page_order(page, order);
574 
575  /*
576  * If this is not the largest possible page, check if the buddy
577  * of the next-highest order is free. If it is, it's possible
578  * that pages are being freed that will coalesce soon. In case,
579  * that is happening, add the free page to the tail of the list
580  * so it's less likely to be used soon and more likely to be merged
581  * as a higher order page
582  */
583  if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
584  struct page *higher_page, *higher_buddy;
585  combined_idx = buddy_idx & page_idx;
586  higher_page = page + (combined_idx - page_idx);
587  buddy_idx = __find_buddy_index(combined_idx, order + 1);
588  higher_buddy = higher_page + (buddy_idx - combined_idx);
589  if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
590  list_add_tail(&page->lru,
591  &zone->free_area[order].free_list[migratetype]);
592  goto out;
593  }
594  }
595 
596  list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
597 out:
598  zone->free_area[order].nr_free++;
599 }
600 
601 static inline int free_pages_check(struct page *page)
602 {
603  if (unlikely(page_mapcount(page) |
604  (page->mapping != NULL) |
605  (atomic_read(&page->_count) != 0) |
606  (page->flags & PAGE_FLAGS_CHECK_AT_FREE) |
607  (mem_cgroup_bad_page_check(page)))) {
608  bad_page(page);
609  return 1;
610  }
611  if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
613  return 0;
614 }
615 
616 /*
617  * Frees a number of pages from the PCP lists
618  * Assumes all pages on list are in same zone, and of same order.
619  * count is the number of pages to free.
620  *
621  * If the zone was previously in an "all pages pinned" state then look to
622  * see if this freeing clears that state.
623  *
624  * And clear the zone's pages_scanned counter, to hold off the "all pages are
625  * pinned" detection logic.
626  */
627 static void free_pcppages_bulk(struct zone *zone, int count,
628  struct per_cpu_pages *pcp)
629 {
630  int migratetype = 0;
631  int batch_free = 0;
632  int to_free = count;
633 
634  spin_lock(&zone->lock);
635  zone->all_unreclaimable = 0;
636  zone->pages_scanned = 0;
637 
638  while (to_free) {
639  struct page *page;
640  struct list_head *list;
641 
642  /*
643  * Remove pages from lists in a round-robin fashion. A
644  * batch_free count is maintained that is incremented when an
645  * empty list is encountered. This is so more pages are freed
646  * off fuller lists instead of spinning excessively around empty
647  * lists
648  */
649  do {
650  batch_free++;
651  if (++migratetype == MIGRATE_PCPTYPES)
652  migratetype = 0;
653  list = &pcp->lists[migratetype];
654  } while (list_empty(list));
655 
656  /* This is the only non-empty list. Free them all. */
657  if (batch_free == MIGRATE_PCPTYPES)
658  batch_free = to_free;
659 
660  do {
661  int mt; /* migratetype of the to-be-freed page */
662 
663  page = list_entry(list->prev, struct page, lru);
664  /* must delete as __free_one_page list manipulates */
665  list_del(&page->lru);
666  mt = get_freepage_migratetype(page);
667  /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
668  __free_one_page(page, zone, 0, mt);
669  trace_mm_page_pcpu_drain(page, 0, mt);
670  if (is_migrate_cma(mt))
671  __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1);
672  } while (--to_free && --batch_free && !list_empty(list));
673  }
674  __mod_zone_page_state(zone, NR_FREE_PAGES, count);
675  spin_unlock(&zone->lock);
676 }
677 
678 static void free_one_page(struct zone *zone, struct page *page, int order,
679  int migratetype)
680 {
681  spin_lock(&zone->lock);
682  zone->all_unreclaimable = 0;
683  zone->pages_scanned = 0;
684 
685  __free_one_page(page, zone, order, migratetype);
686  if (unlikely(migratetype != MIGRATE_ISOLATE))
687  __mod_zone_freepage_state(zone, 1 << order, migratetype);
688  spin_unlock(&zone->lock);
689 }
690 
691 static bool free_pages_prepare(struct page *page, unsigned int order)
692 {
693  int i;
694  int bad = 0;
695 
696  trace_mm_page_free(page, order);
697  kmemcheck_free_shadow(page, order);
698 
699  if (PageAnon(page))
700  page->mapping = NULL;
701  for (i = 0; i < (1 << order); i++)
702  bad += free_pages_check(page + i);
703  if (bad)
704  return false;
705 
706  if (!PageHighMem(page)) {
708  debug_check_no_obj_freed(page_address(page),
709  PAGE_SIZE << order);
710  }
711  arch_free_page(page, order);
712  kernel_map_pages(page, 1 << order, 0);
713 
714  return true;
715 }
716 
717 static void __free_pages_ok(struct page *page, unsigned int order)
718 {
719  unsigned long flags;
720  int migratetype;
721 
722  if (!free_pages_prepare(page, order))
723  return;
724 
725  local_irq_save(flags);
726  __count_vm_events(PGFREE, 1 << order);
727  migratetype = get_pageblock_migratetype(page);
728  set_freepage_migratetype(page, migratetype);
729  free_one_page(page_zone(page), page, order, migratetype);
730  local_irq_restore(flags);
731 }
732 
733 void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
734 {
735  unsigned int nr_pages = 1 << order;
736  unsigned int loop;
737 
738  prefetchw(page);
739  for (loop = 0; loop < nr_pages; loop++) {
740  struct page *p = &page[loop];
741 
742  if (loop + 1 < nr_pages)
743  prefetchw(p + 1);
744  __ClearPageReserved(p);
745  set_page_count(p, 0);
746  }
747 
748  set_page_refcounted(page);
749  __free_pages(page, order);
750 }
751 
752 #ifdef CONFIG_CMA
753 /* Free whole pageblock and set it's migration type to MIGRATE_CMA. */
754 void __init init_cma_reserved_pageblock(struct page *page)
755 {
756  unsigned i = pageblock_nr_pages;
757  struct page *p = page;
758 
759  do {
760  __ClearPageReserved(p);
761  set_page_count(p, 0);
762  } while (++p, --i);
763 
764  set_page_refcounted(page);
765  set_pageblock_migratetype(page, MIGRATE_CMA);
767  totalram_pages += pageblock_nr_pages;
768 }
769 #endif
770 
771 /*
772  * The order of subdivision here is critical for the IO subsystem.
773  * Please do not alter this order without good reasons and regression
774  * testing. Specifically, as large blocks of memory are subdivided,
775  * the order in which smaller blocks are delivered depends on the order
776  * they're subdivided in this function. This is the primary factor
777  * influencing the order in which pages are delivered to the IO
778  * subsystem according to empirical testing, and this is also justified
779  * by considering the behavior of a buddy system containing a single
780  * large block of memory acted on by a series of small allocations.
781  * This behavior is a critical factor in sglist merging's success.
782  *
783  * -- wli
784  */
785 static inline void expand(struct zone *zone, struct page *page,
786  int low, int high, struct free_area *area,
787  int migratetype)
788 {
789  unsigned long size = 1 << high;
790 
791  while (high > low) {
792  area--;
793  high--;
794  size >>= 1;
795  VM_BUG_ON(bad_range(zone, &page[size]));
796 
797 #ifdef CONFIG_DEBUG_PAGEALLOC
798  if (high < debug_guardpage_minorder()) {
799  /*
800  * Mark as guard pages (or page), that will allow to
801  * merge back to allocator when buddy will be freed.
802  * Corresponding page table entries will not be touched,
803  * pages will stay not present in virtual address space
804  */
805  INIT_LIST_HEAD(&page[size].lru);
806  set_page_guard_flag(&page[size]);
807  set_page_private(&page[size], high);
808  /* Guard pages are not available for any usage */
809  __mod_zone_freepage_state(zone, -(1 << high),
810  migratetype);
811  continue;
812  }
813 #endif
814  list_add(&page[size].lru, &area->free_list[migratetype]);
815  area->nr_free++;
816  set_page_order(&page[size], high);
817  }
818 }
819 
820 /*
821  * This page is about to be returned from the page allocator
822  */
823 static inline int check_new_page(struct page *page)
824 {
825  if (unlikely(page_mapcount(page) |
826  (page->mapping != NULL) |
827  (atomic_read(&page->_count) != 0) |
828  (page->flags & PAGE_FLAGS_CHECK_AT_PREP) |
829  (mem_cgroup_bad_page_check(page)))) {
830  bad_page(page);
831  return 1;
832  }
833  return 0;
834 }
835 
836 static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
837 {
838  int i;
839 
840  for (i = 0; i < (1 << order); i++) {
841  struct page *p = page + i;
842  if (unlikely(check_new_page(p)))
843  return 1;
844  }
845 
846  set_page_private(page, 0);
847  set_page_refcounted(page);
848 
849  arch_alloc_page(page, order);
850  kernel_map_pages(page, 1 << order, 1);
851 
852  if (gfp_flags & __GFP_ZERO)
853  prep_zero_page(page, order, gfp_flags);
854 
855  if (order && (gfp_flags & __GFP_COMP))
856  prep_compound_page(page, order);
857 
858  return 0;
859 }
860 
861 /*
862  * Go through the free lists for the given migratetype and remove
863  * the smallest available page from the freelists
864  */
865 static inline
866 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
867  int migratetype)
868 {
869  unsigned int current_order;
870  struct free_area * area;
871  struct page *page;
872 
873  /* Find a page of the appropriate size in the preferred list */
874  for (current_order = order; current_order < MAX_ORDER; ++current_order) {
875  area = &(zone->free_area[current_order]);
876  if (list_empty(&area->free_list[migratetype]))
877  continue;
878 
879  page = list_entry(area->free_list[migratetype].next,
880  struct page, lru);
881  list_del(&page->lru);
882  rmv_page_order(page);
883  area->nr_free--;
884  expand(zone, page, order, current_order, area, migratetype);
885  return page;
886  }
887 
888  return NULL;
889 }
890 
891 
892 /*
893  * This array describes the order lists are fallen back to when
894  * the free lists for the desirable migrate type are depleted
895  */
896 static int fallbacks[MIGRATE_TYPES][4] = {
899 #ifdef CONFIG_CMA
901  [MIGRATE_CMA] = { MIGRATE_RESERVE }, /* Never used */
902 #else
904 #endif
905  [MIGRATE_RESERVE] = { MIGRATE_RESERVE }, /* Never used */
906  [MIGRATE_ISOLATE] = { MIGRATE_RESERVE }, /* Never used */
907 };
908 
909 /*
910  * Move the free pages in a range to the free lists of the requested type.
911  * Note that start_page and end_pages are not aligned on a pageblock
912  * boundary. If alignment is required, use move_freepages_block()
913  */
914 int move_freepages(struct zone *zone,
915  struct page *start_page, struct page *end_page,
916  int migratetype)
917 {
918  struct page *page;
919  unsigned long order;
920  int pages_moved = 0;
921 
922 #ifndef CONFIG_HOLES_IN_ZONE
923  /*
924  * page_zone is not safe to call in this context when
925  * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
926  * anyway as we check zone boundaries in move_freepages_block().
927  * Remove at a later date when no bug reports exist related to
928  * grouping pages by mobility
929  */
930  BUG_ON(page_zone(start_page) != page_zone(end_page));
931 #endif
932 
933  for (page = start_page; page <= end_page;) {
934  /* Make sure we are not inadvertently changing nodes */
935  VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));
936 
937  if (!pfn_valid_within(page_to_pfn(page))) {
938  page++;
939  continue;
940  }
941 
942  if (!PageBuddy(page)) {
943  page++;
944  continue;
945  }
946 
947  order = page_order(page);
948  list_move(&page->lru,
949  &zone->free_area[order].free_list[migratetype]);
950  set_freepage_migratetype(page, migratetype);
951  page += 1 << order;
952  pages_moved += 1 << order;
953  }
954 
955  return pages_moved;
956 }
957 
958 int move_freepages_block(struct zone *zone, struct page *page,
959  int migratetype)
960 {
961  unsigned long start_pfn, end_pfn;
962  struct page *start_page, *end_page;
963 
964  start_pfn = page_to_pfn(page);
965  start_pfn = start_pfn & ~(pageblock_nr_pages-1);
966  start_page = pfn_to_page(start_pfn);
967  end_page = start_page + pageblock_nr_pages - 1;
968  end_pfn = start_pfn + pageblock_nr_pages - 1;
969 
970  /* Do not cross zone boundaries */
971  if (start_pfn < zone->zone_start_pfn)
972  start_page = page;
973  if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages)
974  return 0;
975 
976  return move_freepages(zone, start_page, end_page, migratetype);
977 }
978 
979 static void change_pageblock_range(struct page *pageblock_page,
980  int start_order, int migratetype)
981 {
982  int nr_pageblocks = 1 << (start_order - pageblock_order);
983 
984  while (nr_pageblocks--) {
985  set_pageblock_migratetype(pageblock_page, migratetype);
986  pageblock_page += pageblock_nr_pages;
987  }
988 }
989 
990 /* Remove an element from the buddy allocator from the fallback list */
991 static inline struct page *
992 __rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
993 {
994  struct free_area * area;
995  int current_order;
996  struct page *page;
997  int migratetype, i;
998 
999  /* Find the largest possible block of pages in the other list */
1000  for (current_order = MAX_ORDER-1; current_order >= order;
1001  --current_order) {
1002  for (i = 0;; i++) {
1003  migratetype = fallbacks[start_migratetype][i];
1004 
1005  /* MIGRATE_RESERVE handled later if necessary */
1006  if (migratetype == MIGRATE_RESERVE)
1007  break;
1008 
1009  area = &(zone->free_area[current_order]);
1010  if (list_empty(&area->free_list[migratetype]))
1011  continue;
1012 
1013  page = list_entry(area->free_list[migratetype].next,
1014  struct page, lru);
1015  area->nr_free--;
1016 
1017  /*
1018  * If breaking a large block of pages, move all free
1019  * pages to the preferred allocation list. If falling
1020  * back for a reclaimable kernel allocation, be more
1021  * aggressive about taking ownership of free pages
1022  *
1023  * On the other hand, never change migration
1024  * type of MIGRATE_CMA pageblocks nor move CMA
1025  * pages on different free lists. We don't
1026  * want unmovable pages to be allocated from
1027  * MIGRATE_CMA areas.
1028  */
1029  if (!is_migrate_cma(migratetype) &&
1030  (unlikely(current_order >= pageblock_order / 2) ||
1031  start_migratetype == MIGRATE_RECLAIMABLE ||
1032  page_group_by_mobility_disabled)) {
1033  int pages;
1034  pages = move_freepages_block(zone, page,
1035  start_migratetype);
1036 
1037  /* Claim the whole block if over half of it is free */
1038  if (pages >= (1 << (pageblock_order-1)) ||
1039  page_group_by_mobility_disabled)
1041  start_migratetype);
1042 
1043  migratetype = start_migratetype;
1044  }
1045 
1046  /* Remove the page from the freelists */
1047  list_del(&page->lru);
1048  rmv_page_order(page);
1049 
1050  /* Take ownership for orders >= pageblock_order */
1051  if (current_order >= pageblock_order &&
1052  !is_migrate_cma(migratetype))
1053  change_pageblock_range(page, current_order,
1054  start_migratetype);
1055 
1056  expand(zone, page, order, current_order, area,
1057  is_migrate_cma(migratetype)
1058  ? migratetype : start_migratetype);
1059 
1060  trace_mm_page_alloc_extfrag(page, order, current_order,
1061  start_migratetype, migratetype);
1062 
1063  return page;
1064  }
1065  }
1066 
1067  return NULL;
1068 }
1069 
1070 /*
1071  * Do the hard work of removing an element from the buddy allocator.
1072  * Call me with the zone->lock already held.
1073  */
1074 static struct page *__rmqueue(struct zone *zone, unsigned int order,
1075  int migratetype)
1076 {
1077  struct page *page;
1078 
1079 retry_reserve:
1080  page = __rmqueue_smallest(zone, order, migratetype);
1081 
1082  if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
1083  page = __rmqueue_fallback(zone, order, migratetype);
1084 
1085  /*
1086  * Use MIGRATE_RESERVE rather than fail an allocation. goto
1087  * is used because __rmqueue_smallest is an inline function
1088  * and we want just one call site
1089  */
1090  if (!page) {
1091  migratetype = MIGRATE_RESERVE;
1092  goto retry_reserve;
1093  }
1094  }
1095 
1096  trace_mm_page_alloc_zone_locked(page, order, migratetype);
1097  return page;
1098 }
1099 
1100 /*
1101  * Obtain a specified number of elements from the buddy allocator, all under
1102  * a single hold of the lock, for efficiency. Add them to the supplied list.
1103  * Returns the number of new pages which were placed at *list.
1104  */
1105 static int rmqueue_bulk(struct zone *zone, unsigned int order,
1106  unsigned long count, struct list_head *list,
1107  int migratetype, int cold)
1108 {
1109  int mt = migratetype, i;
1110 
1111  spin_lock(&zone->lock);
1112  for (i = 0; i < count; ++i) {
1113  struct page *page = __rmqueue(zone, order, migratetype);
1114  if (unlikely(page == NULL))
1115  break;
1116 
1117  /*
1118  * Split buddy pages returned by expand() are received here
1119  * in physical page order. The page is added to the callers and
1120  * list and the list head then moves forward. From the callers
1121  * perspective, the linked list is ordered by page number in
1122  * some conditions. This is useful for IO devices that can
1123  * merge IO requests if the physical pages are ordered
1124  * properly.
1125  */
1126  if (likely(cold == 0))
1127  list_add(&page->lru, list);
1128  else
1129  list_add_tail(&page->lru, list);
1130  if (IS_ENABLED(CONFIG_CMA)) {
1131  mt = get_pageblock_migratetype(page);
1132  if (!is_migrate_cma(mt) && mt != MIGRATE_ISOLATE)
1133  mt = migratetype;
1134  }
1135  set_freepage_migratetype(page, mt);
1136  list = &page->lru;
1137  if (is_migrate_cma(mt))
1138  __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
1139  -(1 << order));
1140  }
1141  __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
1142  spin_unlock(&zone->lock);
1143  return i;
1144 }
1145 
1146 #ifdef CONFIG_NUMA
1147 /*
1148  * Called from the vmstat counter updater to drain pagesets of this
1149  * currently executing processor on remote nodes after they have
1150  * expired.
1151  *
1152  * Note that this function must be called with the thread pinned to
1153  * a single processor.
1154  */
1155 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
1156 {
1157  unsigned long flags;
1158  int to_drain;
1159 
1160  local_irq_save(flags);
1161  if (pcp->count >= pcp->batch)
1162  to_drain = pcp->batch;
1163  else
1164  to_drain = pcp->count;
1165  if (to_drain > 0) {
1166  free_pcppages_bulk(zone, to_drain, pcp);
1167  pcp->count -= to_drain;
1168  }
1169  local_irq_restore(flags);
1170 }
1171 #endif
1172 
1173 /*
1174  * Drain pages of the indicated processor.
1175  *
1176  * The processor must either be the current processor and the
1177  * thread pinned to the current processor or a processor that
1178  * is not online.
1179  */
1180 static void drain_pages(unsigned int cpu)
1181 {
1182  unsigned long flags;
1183  struct zone *zone;
1184 
1185  for_each_populated_zone(zone) {
1186  struct per_cpu_pageset *pset;
1187  struct per_cpu_pages *pcp;
1188 
1189  local_irq_save(flags);
1190  pset = per_cpu_ptr(zone->pageset, cpu);
1191 
1192  pcp = &pset->pcp;
1193  if (pcp->count) {
1194  free_pcppages_bulk(zone, pcp->count, pcp);
1195  pcp->count = 0;
1196  }
1197  local_irq_restore(flags);
1198  }
1199 }
1200 
1201 /*
1202  * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1203  */
1205 {
1206  drain_pages(smp_processor_id());
1207 }
1208 
1209 /*
1210  * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
1211  *
1212  * Note that this code is protected against sending an IPI to an offline
1213  * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
1214  * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
1215  * nothing keeps CPUs from showing up after we populated the cpumask and
1216  * before the call to on_each_cpu_mask().
1217  */
1219 {
1220  int cpu;
1221  struct per_cpu_pageset *pcp;
1222  struct zone *zone;
1223 
1224  /*
1225  * Allocate in the BSS so we wont require allocation in
1226  * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
1227  */
1228  static cpumask_t cpus_with_pcps;
1229 
1230  /*
1231  * We don't care about racing with CPU hotplug event
1232  * as offline notification will cause the notified
1233  * cpu to drain that CPU pcps and on_each_cpu_mask
1234  * disables preemption as part of its processing
1235  */
1236  for_each_online_cpu(cpu) {
1237  bool has_pcps = false;
1238  for_each_populated_zone(zone) {
1239  pcp = per_cpu_ptr(zone->pageset, cpu);
1240  if (pcp->pcp.count) {
1241  has_pcps = true;
1242  break;
1243  }
1244  }
1245  if (has_pcps)
1246  cpumask_set_cpu(cpu, &cpus_with_pcps);
1247  else
1248  cpumask_clear_cpu(cpu, &cpus_with_pcps);
1249  }
1250  on_each_cpu_mask(&cpus_with_pcps, drain_local_pages, NULL, 1);
1251 }
1252 
1253 #ifdef CONFIG_HIBERNATION
1254 
1255 void mark_free_pages(struct zone *zone)
1256 {
1257  unsigned long pfn, max_zone_pfn;
1258  unsigned long flags;
1259  int order, t;
1260  struct list_head *curr;
1261 
1262  if (!zone->spanned_pages)
1263  return;
1264 
1265  spin_lock_irqsave(&zone->lock, flags);
1266 
1267  max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
1268  for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1269  if (pfn_valid(pfn)) {
1270  struct page *page = pfn_to_page(pfn);
1271 
1272  if (!swsusp_page_is_forbidden(page))
1273  swsusp_unset_page_free(page);
1274  }
1275 
1276  for_each_migratetype_order(order, t) {
1277  list_for_each(curr, &zone->free_area[order].free_list[t]) {
1278  unsigned long i;
1279 
1280  pfn = page_to_pfn(list_entry(curr, struct page, lru));
1281  for (i = 0; i < (1UL << order); i++)
1283  }
1284  }
1285  spin_unlock_irqrestore(&zone->lock, flags);
1286 }
1287 #endif /* CONFIG_PM */
1288 
1289 /*
1290  * Free a 0-order page
1291  * cold == 1 ? free a cold page : free a hot page
1292  */
1293 void free_hot_cold_page(struct page *page, int cold)
1294 {
1295  struct zone *zone = page_zone(page);
1296  struct per_cpu_pages *pcp;
1297  unsigned long flags;
1298  int migratetype;
1299 
1300  if (!free_pages_prepare(page, 0))
1301  return;
1302 
1303  migratetype = get_pageblock_migratetype(page);
1304  set_freepage_migratetype(page, migratetype);
1305  local_irq_save(flags);
1306  __count_vm_event(PGFREE);
1307 
1308  /*
1309  * We only track unmovable, reclaimable and movable on pcp lists.
1310  * Free ISOLATE pages back to the allocator because they are being
1311  * offlined but treat RESERVE as movable pages so we can get those
1312  * areas back if necessary. Otherwise, we may have to free
1313  * excessively into the page allocator
1314  */
1315  if (migratetype >= MIGRATE_PCPTYPES) {
1316  if (unlikely(migratetype == MIGRATE_ISOLATE)) {
1317  free_one_page(zone, page, 0, migratetype);
1318  goto out;
1319  }
1320  migratetype = MIGRATE_MOVABLE;
1321  }
1322 
1323  pcp = &this_cpu_ptr(zone->pageset)->pcp;
1324  if (cold)
1325  list_add_tail(&page->lru, &pcp->lists[migratetype]);
1326  else
1327  list_add(&page->lru, &pcp->lists[migratetype]);
1328  pcp->count++;
1329  if (pcp->count >= pcp->high) {
1330  free_pcppages_bulk(zone, pcp->batch, pcp);
1331  pcp->count -= pcp->batch;
1332  }
1333 
1334 out:
1335  local_irq_restore(flags);
1336 }
1337 
1338 /*
1339  * Free a list of 0-order pages
1340  */
1341 void free_hot_cold_page_list(struct list_head *list, int cold)
1342 {
1343  struct page *page, *next;
1344 
1345  list_for_each_entry_safe(page, next, list, lru) {
1346  trace_mm_page_free_batched(page, cold);
1347  free_hot_cold_page(page, cold);
1348  }
1349 }
1350 
1351 /*
1352  * split_page takes a non-compound higher-order page, and splits it into
1353  * n (1<<order) sub-pages: page[0..n]
1354  * Each sub-page must be freed individually.
1355  *
1356  * Note: this is probably too low level an operation for use in drivers.
1357  * Please consult with lkml before using this in your driver.
1358  */
1359 void split_page(struct page *page, unsigned int order)
1360 {
1361  int i;
1362 
1363  VM_BUG_ON(PageCompound(page));
1364  VM_BUG_ON(!page_count(page));
1365 
1366 #ifdef CONFIG_KMEMCHECK
1367  /*
1368  * Split shadow pages too, because free(page[0]) would
1369  * otherwise free the whole shadow.
1370  */
1371  if (kmemcheck_page_is_tracked(page))
1372  split_page(virt_to_page(page[0].shadow), order);
1373 #endif
1374 
1375  for (i = 1; i < (1 << order); i++)
1376  set_page_refcounted(page + i);
1377 }
1378 
1379 /*
1380  * Similar to the split_page family of functions except that the page
1381  * required at the given order and being isolated now to prevent races
1382  * with parallel allocators
1383  */
1384 int capture_free_page(struct page *page, int alloc_order, int migratetype)
1385 {
1386  unsigned int order;
1387  unsigned long watermark;
1388  struct zone *zone;
1389  int mt;
1390 
1391  BUG_ON(!PageBuddy(page));
1392 
1393  zone = page_zone(page);
1394  order = page_order(page);
1395 
1396  /* Obey watermarks as if the page was being allocated */
1397  watermark = low_wmark_pages(zone) + (1 << order);
1398  if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
1399  return 0;
1400 
1401  /* Remove page from free list */
1402  list_del(&page->lru);
1403  zone->free_area[order].nr_free--;
1404  rmv_page_order(page);
1405 
1406  mt = get_pageblock_migratetype(page);
1407  if (unlikely(mt != MIGRATE_ISOLATE))
1408  __mod_zone_freepage_state(zone, -(1UL << alloc_order), mt);
1409 
1410  if (alloc_order != order)
1411  expand(zone, page, alloc_order, order,
1412  &zone->free_area[order], migratetype);
1413 
1414  /* Set the pageblock if the captured page is at least a pageblock */
1415  if (order >= pageblock_order - 1) {
1416  struct page *endpage = page + (1 << order) - 1;
1417  for (; page < endpage; page += pageblock_nr_pages) {
1418  int mt = get_pageblock_migratetype(page);
1419  if (mt != MIGRATE_ISOLATE && !is_migrate_cma(mt))
1421  MIGRATE_MOVABLE);
1422  }
1423  }
1424 
1425  return 1UL << alloc_order;
1426 }
1427 
1428 /*
1429  * Similar to split_page except the page is already free. As this is only
1430  * being used for migration, the migratetype of the block also changes.
1431  * As this is called with interrupts disabled, the caller is responsible
1432  * for calling arch_alloc_page() and kernel_map_page() after interrupts
1433  * are enabled.
1434  *
1435  * Note: this is probably too low level an operation for use in drivers.
1436  * Please consult with lkml before using this in your driver.
1437  */
1438 int split_free_page(struct page *page)
1439 {
1440  unsigned int order;
1441  int nr_pages;
1442 
1443  BUG_ON(!PageBuddy(page));
1444  order = page_order(page);
1445 
1446  nr_pages = capture_free_page(page, order, 0);
1447  if (!nr_pages)
1448  return 0;
1449 
1450  /* Split into individual pages */
1451  set_page_refcounted(page);
1452  split_page(page, order);
1453  return nr_pages;
1454 }
1455 
1456 /*
1457  * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1458  * we cheat by calling it from here, in the order > 0 path. Saves a branch
1459  * or two.
1460  */
1461 static inline
1462 struct page *buffered_rmqueue(struct zone *preferred_zone,
1463  struct zone *zone, int order, gfp_t gfp_flags,
1464  int migratetype)
1465 {
1466  unsigned long flags;
1467  struct page *page;
1468  int cold = !!(gfp_flags & __GFP_COLD);
1469 
1470 again:
1471  if (likely(order == 0)) {
1472  struct per_cpu_pages *pcp;
1473  struct list_head *list;
1474 
1475  local_irq_save(flags);
1476  pcp = &this_cpu_ptr(zone->pageset)->pcp;
1477  list = &pcp->lists[migratetype];
1478  if (list_empty(list)) {
1479  pcp->count += rmqueue_bulk(zone, 0,
1480  pcp->batch, list,
1481  migratetype, cold);
1482  if (unlikely(list_empty(list)))
1483  goto failed;
1484  }
1485 
1486  if (cold)
1487  page = list_entry(list->prev, struct page, lru);
1488  else
1489  page = list_entry(list->next, struct page, lru);
1490 
1491  list_del(&page->lru);
1492  pcp->count--;
1493  } else {
1494  if (unlikely(gfp_flags & __GFP_NOFAIL)) {
1495  /*
1496  * __GFP_NOFAIL is not to be used in new code.
1497  *
1498  * All __GFP_NOFAIL callers should be fixed so that they
1499  * properly detect and handle allocation failures.
1500  *
1501  * We most definitely don't want callers attempting to
1502  * allocate greater than order-1 page units with
1503  * __GFP_NOFAIL.
1504  */
1505  WARN_ON_ONCE(order > 1);
1506  }
1507  spin_lock_irqsave(&zone->lock, flags);
1508  page = __rmqueue(zone, order, migratetype);
1509  spin_unlock(&zone->lock);
1510  if (!page)
1511  goto failed;
1512  __mod_zone_freepage_state(zone, -(1 << order),
1513  get_pageblock_migratetype(page));
1514  }
1515 
1516  __count_zone_vm_events(PGALLOC, zone, 1 << order);
1517  zone_statistics(preferred_zone, zone, gfp_flags);
1518  local_irq_restore(flags);
1519 
1520  VM_BUG_ON(bad_range(zone, page));
1521  if (prep_new_page(page, order, gfp_flags))
1522  goto again;
1523  return page;
1524 
1525 failed:
1526  local_irq_restore(flags);
1527  return NULL;
1528 }
1529 
1530 #ifdef CONFIG_FAIL_PAGE_ALLOC
1531 
1532 static struct {
1533  struct fault_attr attr;
1534 
1535  u32 ignore_gfp_highmem;
1537  u32 min_order;
1538 } fail_page_alloc = {
1539  .attr = FAULT_ATTR_INITIALIZER,
1540  .ignore_gfp_wait = 1,
1541  .ignore_gfp_highmem = 1,
1542  .min_order = 1,
1543 };
1544 
1545 static int __init setup_fail_page_alloc(char *str)
1546 {
1547  return setup_fault_attr(&fail_page_alloc.attr, str);
1548 }
1549 __setup("fail_page_alloc=", setup_fail_page_alloc);
1550 
1551 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1552 {
1553  if (order < fail_page_alloc.min_order)
1554  return false;
1555  if (gfp_mask & __GFP_NOFAIL)
1556  return false;
1557  if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
1558  return false;
1559  if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
1560  return false;
1561 
1562  return should_fail(&fail_page_alloc.attr, 1 << order);
1563 }
1564 
1565 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1566 
1567 static int __init fail_page_alloc_debugfs(void)
1568 {
1570  struct dentry *dir;
1571 
1572  dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
1573  &fail_page_alloc.attr);
1574  if (IS_ERR(dir))
1575  return PTR_ERR(dir);
1576 
1577  if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
1578  &fail_page_alloc.ignore_gfp_wait))
1579  goto fail;
1580  if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
1581  &fail_page_alloc.ignore_gfp_highmem))
1582  goto fail;
1583  if (!debugfs_create_u32("min-order", mode, dir,
1584  &fail_page_alloc.min_order))
1585  goto fail;
1586 
1587  return 0;
1588 fail:
1590 
1591  return -ENOMEM;
1592 }
1593 
1594 late_initcall(fail_page_alloc_debugfs);
1595 
1596 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1597 
1598 #else /* CONFIG_FAIL_PAGE_ALLOC */
1599 
1600 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1601 {
1602  return false;
1603 }
1604 
1605 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1606 
1607 /*
1608  * Return true if free pages are above 'mark'. This takes into account the order
1609  * of the allocation.
1610  */
1611 static bool __zone_watermark_ok(struct zone *z, int order, unsigned long mark,
1612  int classzone_idx, int alloc_flags, long free_pages)
1613 {
1614  /* free_pages my go negative - that's OK */
1615  long min = mark;
1616  long lowmem_reserve = z->lowmem_reserve[classzone_idx];
1617  int o;
1618 
1619  free_pages -= (1 << order) - 1;
1620  if (alloc_flags & ALLOC_HIGH)
1621  min -= min / 2;
1622  if (alloc_flags & ALLOC_HARDER)
1623  min -= min / 4;
1624 #ifdef CONFIG_CMA
1625  /* If allocation can't use CMA areas don't use free CMA pages */
1626  if (!(alloc_flags & ALLOC_CMA))
1627  free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES);
1628 #endif
1629  if (free_pages <= min + lowmem_reserve)
1630  return false;
1631  for (o = 0; o < order; o++) {
1632  /* At the next order, this order's pages become unavailable */
1633  free_pages -= z->free_area[o].nr_free << o;
1634 
1635  /* Require fewer higher order pages to be free */
1636  min >>= 1;
1637 
1638  if (free_pages <= min)
1639  return false;
1640  }
1641  return true;
1642 }
1643 
1644 #ifdef CONFIG_MEMORY_ISOLATION
1645 static inline unsigned long nr_zone_isolate_freepages(struct zone *zone)
1646 {
1647  if (unlikely(zone->nr_pageblock_isolate))
1648  return zone->nr_pageblock_isolate * pageblock_nr_pages;
1649  return 0;
1650 }
1651 #else
1652 static inline unsigned long nr_zone_isolate_freepages(struct zone *zone)
1653 {
1654  return 0;
1655 }
1656 #endif
1657 
1658 bool zone_watermark_ok(struct zone *z, int order, unsigned long mark,
1659  int classzone_idx, int alloc_flags)
1660 {
1661  return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
1662  zone_page_state(z, NR_FREE_PAGES));
1663 }
1664 
1665 bool zone_watermark_ok_safe(struct zone *z, int order, unsigned long mark,
1666  int classzone_idx, int alloc_flags)
1667 {
1668  long free_pages = zone_page_state(z, NR_FREE_PAGES);
1669 
1670  if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
1671  free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
1672 
1673  /*
1674  * If the zone has MIGRATE_ISOLATE type free pages, we should consider
1675  * it. nr_zone_isolate_freepages is never accurate so kswapd might not
1676  * sleep although it could do so. But this is more desirable for memory
1677  * hotplug than sleeping which can cause a livelock in the direct
1678  * reclaim path.
1679  */
1680  free_pages -= nr_zone_isolate_freepages(z);
1681  return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
1682  free_pages);
1683 }
1684 
1685 #ifdef CONFIG_NUMA
1686 /*
1687  * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1688  * skip over zones that are not allowed by the cpuset, or that have
1689  * been recently (in last second) found to be nearly full. See further
1690  * comments in mmzone.h. Reduces cache footprint of zonelist scans
1691  * that have to skip over a lot of full or unallowed zones.
1692  *
1693  * If the zonelist cache is present in the passed in zonelist, then
1694  * returns a pointer to the allowed node mask (either the current
1695  * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1696  *
1697  * If the zonelist cache is not available for this zonelist, does
1698  * nothing and returns NULL.
1699  *
1700  * If the fullzones BITMAP in the zonelist cache is stale (more than
1701  * a second since last zap'd) then we zap it out (clear its bits.)
1702  *
1703  * We hold off even calling zlc_setup, until after we've checked the
1704  * first zone in the zonelist, on the theory that most allocations will
1705  * be satisfied from that first zone, so best to examine that zone as
1706  * quickly as we can.
1707  */
1708 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1709 {
1710  struct zonelist_cache *zlc; /* cached zonelist speedup info */
1711  nodemask_t *allowednodes; /* zonelist_cache approximation */
1712 
1713  zlc = zonelist->zlcache_ptr;
1714  if (!zlc)
1715  return NULL;
1716 
1717  if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1718  bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1719  zlc->last_full_zap = jiffies;
1720  }
1721 
1722  allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
1725  return allowednodes;
1726 }
1727 
1728 /*
1729  * Given 'z' scanning a zonelist, run a couple of quick checks to see
1730  * if it is worth looking at further for free memory:
1731  * 1) Check that the zone isn't thought to be full (doesn't have its
1732  * bit set in the zonelist_cache fullzones BITMAP).
1733  * 2) Check that the zones node (obtained from the zonelist_cache
1734  * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1735  * Return true (non-zero) if zone is worth looking at further, or
1736  * else return false (zero) if it is not.
1737  *
1738  * This check -ignores- the distinction between various watermarks,
1739  * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1740  * found to be full for any variation of these watermarks, it will
1741  * be considered full for up to one second by all requests, unless
1742  * we are so low on memory on all allowed nodes that we are forced
1743  * into the second scan of the zonelist.
1744  *
1745  * In the second scan we ignore this zonelist cache and exactly
1746  * apply the watermarks to all zones, even it is slower to do so.
1747  * We are low on memory in the second scan, and should leave no stone
1748  * unturned looking for a free page.
1749  */
1750 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1751  nodemask_t *allowednodes)
1752 {
1753  struct zonelist_cache *zlc; /* cached zonelist speedup info */
1754  int i; /* index of *z in zonelist zones */
1755  int n; /* node that zone *z is on */
1756 
1757  zlc = zonelist->zlcache_ptr;
1758  if (!zlc)
1759  return 1;
1760 
1761  i = z - zonelist->_zonerefs;
1762  n = zlc->z_to_n[i];
1763 
1764  /* This zone is worth trying if it is allowed but not full */
1765  return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones);
1766 }
1767 
1768 /*
1769  * Given 'z' scanning a zonelist, set the corresponding bit in
1770  * zlc->fullzones, so that subsequent attempts to allocate a page
1771  * from that zone don't waste time re-examining it.
1772  */
1773 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1774 {
1775  struct zonelist_cache *zlc; /* cached zonelist speedup info */
1776  int i; /* index of *z in zonelist zones */
1777 
1778  zlc = zonelist->zlcache_ptr;
1779  if (!zlc)
1780  return;
1781 
1782  i = z - zonelist->_zonerefs;
1783 
1784  set_bit(i, zlc->fullzones);
1785 }
1786 
1787 /*
1788  * clear all zones full, called after direct reclaim makes progress so that
1789  * a zone that was recently full is not skipped over for up to a second
1790  */
1791 static void zlc_clear_zones_full(struct zonelist *zonelist)
1792 {
1793  struct zonelist_cache *zlc; /* cached zonelist speedup info */
1794 
1795  zlc = zonelist->zlcache_ptr;
1796  if (!zlc)
1797  return;
1798 
1799  bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1800 }
1801 
1802 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
1803 {
1804  return node_isset(local_zone->node, zone->zone_pgdat->reclaim_nodes);
1805 }
1806 
1807 static void __paginginit init_zone_allows_reclaim(int nid)
1808 {
1809  int i;
1810 
1812  if (node_distance(nid, i) <= RECLAIM_DISTANCE)
1813  node_set(i, NODE_DATA(nid)->reclaim_nodes);
1814  else
1815  zone_reclaim_mode = 1;
1816 }
1817 
1818 #else /* CONFIG_NUMA */
1819 
1820 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1821 {
1822  return NULL;
1823 }
1824 
1825 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1826  nodemask_t *allowednodes)
1827 {
1828  return 1;
1829 }
1830 
1831 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1832 {
1833 }
1834 
1835 static void zlc_clear_zones_full(struct zonelist *zonelist)
1836 {
1837 }
1838 
1839 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
1840 {
1841  return true;
1842 }
1843 
1844 static inline void init_zone_allows_reclaim(int nid)
1845 {
1846 }
1847 #endif /* CONFIG_NUMA */
1848 
1849 /*
1850  * get_page_from_freelist goes through the zonelist trying to allocate
1851  * a page.
1852  */
1853 static struct page *
1854 get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1855  struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1856  struct zone *preferred_zone, int migratetype)
1857 {
1858  struct zoneref *z;
1859  struct page *page = NULL;
1860  int classzone_idx;
1861  struct zone *zone;
1862  nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */
1863  int zlc_active = 0; /* set if using zonelist_cache */
1864  int did_zlc_setup = 0; /* just call zlc_setup() one time */
1865 
1866  classzone_idx = zone_idx(preferred_zone);
1867 zonelist_scan:
1868  /*
1869  * Scan zonelist, looking for a zone with enough free.
1870  * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1871  */
1872  for_each_zone_zonelist_nodemask(zone, z, zonelist,
1873  high_zoneidx, nodemask) {
1874  if (NUMA_BUILD && zlc_active &&
1875  !zlc_zone_worth_trying(zonelist, z, allowednodes))
1876  continue;
1877  if ((alloc_flags & ALLOC_CPUSET) &&
1878  !cpuset_zone_allowed_softwall(zone, gfp_mask))
1879  continue;
1880  /*
1881  * When allocating a page cache page for writing, we
1882  * want to get it from a zone that is within its dirty
1883  * limit, such that no single zone holds more than its
1884  * proportional share of globally allowed dirty pages.
1885  * The dirty limits take into account the zone's
1886  * lowmem reserves and high watermark so that kswapd
1887  * should be able to balance it without having to
1888  * write pages from its LRU list.
1889  *
1890  * This may look like it could increase pressure on
1891  * lower zones by failing allocations in higher zones
1892  * before they are full. But the pages that do spill
1893  * over are limited as the lower zones are protected
1894  * by this very same mechanism. It should not become
1895  * a practical burden to them.
1896  *
1897  * XXX: For now, allow allocations to potentially
1898  * exceed the per-zone dirty limit in the slowpath
1899  * (ALLOC_WMARK_LOW unset) before going into reclaim,
1900  * which is important when on a NUMA setup the allowed
1901  * zones are together not big enough to reach the
1902  * global limit. The proper fix for these situations
1903  * will require awareness of zones in the
1904  * dirty-throttling and the flusher threads.
1905  */
1906  if ((alloc_flags & ALLOC_WMARK_LOW) &&
1907  (gfp_mask & __GFP_WRITE) && !zone_dirty_ok(zone))
1908  goto this_zone_full;
1909 
1911  if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1912  unsigned long mark;
1913  int ret;
1914 
1915  mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
1916  if (zone_watermark_ok(zone, order, mark,
1917  classzone_idx, alloc_flags))
1918  goto try_this_zone;
1919 
1920  if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) {
1921  /*
1922  * we do zlc_setup if there are multiple nodes
1923  * and before considering the first zone allowed
1924  * by the cpuset.
1925  */
1926  allowednodes = zlc_setup(zonelist, alloc_flags);
1927  zlc_active = 1;
1928  did_zlc_setup = 1;
1929  }
1930 
1931  if (zone_reclaim_mode == 0 ||
1932  !zone_allows_reclaim(preferred_zone, zone))
1933  goto this_zone_full;
1934 
1935  /*
1936  * As we may have just activated ZLC, check if the first
1937  * eligible zone has failed zone_reclaim recently.
1938  */
1939  if (NUMA_BUILD && zlc_active &&
1940  !zlc_zone_worth_trying(zonelist, z, allowednodes))
1941  continue;
1942 
1943  ret = zone_reclaim(zone, gfp_mask, order);
1944  switch (ret) {
1945  case ZONE_RECLAIM_NOSCAN:
1946  /* did not scan */
1947  continue;
1948  case ZONE_RECLAIM_FULL:
1949  /* scanned but unreclaimable */
1950  continue;
1951  default:
1952  /* did we reclaim enough */
1953  if (!zone_watermark_ok(zone, order, mark,
1954  classzone_idx, alloc_flags))
1955  goto this_zone_full;
1956  }
1957  }
1958 
1959 try_this_zone:
1960  page = buffered_rmqueue(preferred_zone, zone, order,
1961  gfp_mask, migratetype);
1962  if (page)
1963  break;
1964 this_zone_full:
1965  if (NUMA_BUILD)
1966  zlc_mark_zone_full(zonelist, z);
1967  }
1968 
1969  if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) {
1970  /* Disable zlc cache for second zonelist scan */
1971  zlc_active = 0;
1972  goto zonelist_scan;
1973  }
1974 
1975  if (page)
1976  /*
1977  * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was
1978  * necessary to allocate the page. The expectation is
1979  * that the caller is taking steps that will free more
1980  * memory. The caller should avoid the page being used
1981  * for !PFMEMALLOC purposes.
1982  */
1983  page->pfmemalloc = !!(alloc_flags & ALLOC_NO_WATERMARKS);
1984 
1985  return page;
1986 }
1987 
1988 /*
1989  * Large machines with many possible nodes should not always dump per-node
1990  * meminfo in irq context.
1991  */
1992 static inline bool should_suppress_show_mem(void)
1993 {
1994  bool ret = false;
1995 
1996 #if NODES_SHIFT > 8
1997  ret = in_interrupt();
1998 #endif
1999  return ret;
2000 }
2001 
2002 static DEFINE_RATELIMIT_STATE(nopage_rs,
2005 
2006 void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...)
2007 {
2008  unsigned int filter = SHOW_MEM_FILTER_NODES;
2009 
2010  if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
2011  debug_guardpage_minorder() > 0)
2012  return;
2013 
2014  /*
2015  * This documents exceptions given to allocations in certain
2016  * contexts that are allowed to allocate outside current's set
2017  * of allowed nodes.
2018  */
2019  if (!(gfp_mask & __GFP_NOMEMALLOC))
2020  if (test_thread_flag(TIF_MEMDIE) ||
2021  (current->flags & (PF_MEMALLOC | PF_EXITING)))
2022  filter &= ~SHOW_MEM_FILTER_NODES;
2023  if (in_interrupt() || !(gfp_mask & __GFP_WAIT))
2024  filter &= ~SHOW_MEM_FILTER_NODES;
2025 
2026  if (fmt) {
2027  struct va_format vaf;
2028  va_list args;
2029 
2030  va_start(args, fmt);
2031 
2032  vaf.fmt = fmt;
2033  vaf.va = &args;
2034 
2035  pr_warn("%pV", &vaf);
2036 
2037  va_end(args);
2038  }
2039 
2040  pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
2041  current->comm, order, gfp_mask);
2042 
2043  dump_stack();
2044  if (!should_suppress_show_mem())
2045  show_mem(filter);
2046 }
2047 
2048 static inline int
2049 should_alloc_retry(gfp_t gfp_mask, unsigned int order,
2050  unsigned long did_some_progress,
2051  unsigned long pages_reclaimed)
2052 {
2053  /* Do not loop if specifically requested */
2054  if (gfp_mask & __GFP_NORETRY)
2055  return 0;
2056 
2057  /* Always retry if specifically requested */
2058  if (gfp_mask & __GFP_NOFAIL)
2059  return 1;
2060 
2061  /*
2062  * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
2063  * making forward progress without invoking OOM. Suspend also disables
2064  * storage devices so kswapd will not help. Bail if we are suspending.
2065  */
2066  if (!did_some_progress && pm_suspended_storage())
2067  return 0;
2068 
2069  /*
2070  * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
2071  * means __GFP_NOFAIL, but that may not be true in other
2072  * implementations.
2073  */
2074  if (order <= PAGE_ALLOC_COSTLY_ORDER)
2075  return 1;
2076 
2077  /*
2078  * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
2079  * specified, then we retry until we no longer reclaim any pages
2080  * (above), or we've reclaimed an order of pages at least as
2081  * large as the allocation's order. In both cases, if the
2082  * allocation still fails, we stop retrying.
2083  */
2084  if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order))
2085  return 1;
2086 
2087  return 0;
2088 }
2089 
2090 static inline struct page *
2091 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
2092  struct zonelist *zonelist, enum zone_type high_zoneidx,
2093  nodemask_t *nodemask, struct zone *preferred_zone,
2094  int migratetype)
2095 {
2096  struct page *page;
2097 
2098  /* Acquire the OOM killer lock for the zones in zonelist */
2099  if (!try_set_zonelist_oom(zonelist, gfp_mask)) {
2101  return NULL;
2102  }
2103 
2104  /*
2105  * Go through the zonelist yet one more time, keep very high watermark
2106  * here, this is only to catch a parallel oom killing, we must fail if
2107  * we're still under heavy pressure.
2108  */
2109  page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask,
2110  order, zonelist, high_zoneidx,
2111  ALLOC_WMARK_HIGH|ALLOC_CPUSET,
2112  preferred_zone, migratetype);
2113  if (page)
2114  goto out;
2115 
2116  if (!(gfp_mask & __GFP_NOFAIL)) {
2117  /* The OOM killer will not help higher order allocs */
2118  if (order > PAGE_ALLOC_COSTLY_ORDER)
2119  goto out;
2120  /* The OOM killer does not needlessly kill tasks for lowmem */
2121  if (high_zoneidx < ZONE_NORMAL)
2122  goto out;
2123  /*
2124  * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
2125  * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
2126  * The caller should handle page allocation failure by itself if
2127  * it specifies __GFP_THISNODE.
2128  * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
2129  */
2130  if (gfp_mask & __GFP_THISNODE)
2131  goto out;
2132  }
2133  /* Exhausted what can be done so it's blamo time */
2134  out_of_memory(zonelist, gfp_mask, order, nodemask, false);
2135 
2136 out:
2137  clear_zonelist_oom(zonelist, gfp_mask);
2138  return page;
2139 }
2140 
2141 #ifdef CONFIG_COMPACTION
2142 /* Try memory compaction for high-order allocations before reclaim */
2143 static struct page *
2144 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2145  struct zonelist *zonelist, enum zone_type high_zoneidx,
2146  nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
2147  int migratetype, bool sync_migration,
2148  bool *contended_compaction, bool *deferred_compaction,
2149  unsigned long *did_some_progress)
2150 {
2151  struct page *page = NULL;
2152 
2153  if (!order)
2154  return NULL;
2155 
2156  if (compaction_deferred(preferred_zone, order)) {
2157  *deferred_compaction = true;
2158  return NULL;
2159  }
2160 
2161  current->flags |= PF_MEMALLOC;
2162  *did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,
2163  nodemask, sync_migration,
2164  contended_compaction, &page);
2165  current->flags &= ~PF_MEMALLOC;
2166 
2167  /* If compaction captured a page, prep and use it */
2168  if (page) {
2169  prep_new_page(page, order, gfp_mask);
2170  goto got_page;
2171  }
2172 
2173  if (*did_some_progress != COMPACT_SKIPPED) {
2174  /* Page migration frees to the PCP lists but we want merging */
2175  drain_pages(get_cpu());
2176  put_cpu();
2177 
2178  page = get_page_from_freelist(gfp_mask, nodemask,
2179  order, zonelist, high_zoneidx,
2180  alloc_flags & ~ALLOC_NO_WATERMARKS,
2181  preferred_zone, migratetype);
2182  if (page) {
2183 got_page:
2184  preferred_zone->compact_blockskip_flush = false;
2185  preferred_zone->compact_considered = 0;
2186  preferred_zone->compact_defer_shift = 0;
2187  if (order >= preferred_zone->compact_order_failed)
2188  preferred_zone->compact_order_failed = order + 1;
2189  count_vm_event(COMPACTSUCCESS);
2190  return page;
2191  }
2192 
2193  /*
2194  * It's bad if compaction run occurs and fails.
2195  * The most likely reason is that pages exist,
2196  * but not enough to satisfy watermarks.
2197  */
2198  count_vm_event(COMPACTFAIL);
2199 
2200  /*
2201  * As async compaction considers a subset of pageblocks, only
2202  * defer if the failure was a sync compaction failure.
2203  */
2204  if (sync_migration)
2205  defer_compaction(preferred_zone, order);
2206 
2207  cond_resched();
2208  }
2209 
2210  return NULL;
2211 }
2212 #else
2213 static inline struct page *
2214 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
2215  struct zonelist *zonelist, enum zone_type high_zoneidx,
2216  nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
2217  int migratetype, bool sync_migration,
2218  bool *contended_compaction, bool *deferred_compaction,
2219  unsigned long *did_some_progress)
2220 {
2221  return NULL;
2222 }
2223 #endif /* CONFIG_COMPACTION */
2224 
2225 /* Perform direct synchronous page reclaim */
2226 static int
2227 __perform_reclaim(gfp_t gfp_mask, unsigned int order, struct zonelist *zonelist,
2228  nodemask_t *nodemask)
2229 {
2231  int progress;
2232 
2233  cond_resched();
2234 
2235  /* We now go into synchronous reclaim */
2236  cpuset_memory_pressure_bump();
2237  current->flags |= PF_MEMALLOC;
2240  current->reclaim_state = &reclaim_state;
2241 
2242  progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask);
2243 
2244  current->reclaim_state = NULL;
2246  current->flags &= ~PF_MEMALLOC;
2247 
2248  cond_resched();
2249 
2250  return progress;
2251 }
2252 
2253 /* The really slow allocator path where we enter direct reclaim */
2254 static inline struct page *
2255 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
2256  struct zonelist *zonelist, enum zone_type high_zoneidx,
2257  nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
2258  int migratetype, unsigned long *did_some_progress)
2259 {
2260  struct page *page = NULL;
2261  bool drained = false;
2262 
2263  *did_some_progress = __perform_reclaim(gfp_mask, order, zonelist,
2264  nodemask);
2265  if (unlikely(!(*did_some_progress)))
2266  return NULL;
2267 
2268  /* After successful reclaim, reconsider all zones for allocation */
2269  if (NUMA_BUILD)
2270  zlc_clear_zones_full(zonelist);
2271 
2272 retry:
2273  page = get_page_from_freelist(gfp_mask, nodemask, order,
2274  zonelist, high_zoneidx,
2275  alloc_flags & ~ALLOC_NO_WATERMARKS,
2276  preferred_zone, migratetype);
2277 
2278  /*
2279  * If an allocation failed after direct reclaim, it could be because
2280  * pages are pinned on the per-cpu lists. Drain them and try again
2281  */
2282  if (!page && !drained) {
2283  drain_all_pages();
2284  drained = true;
2285  goto retry;
2286  }
2287 
2288  return page;
2289 }
2290 
2291 /*
2292  * This is called in the allocator slow-path if the allocation request is of
2293  * sufficient urgency to ignore watermarks and take other desperate measures
2294  */
2295 static inline struct page *
2296 __alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
2297  struct zonelist *zonelist, enum zone_type high_zoneidx,
2298  nodemask_t *nodemask, struct zone *preferred_zone,
2299  int migratetype)
2300 {
2301  struct page *page;
2302 
2303  do {
2304  page = get_page_from_freelist(gfp_mask, nodemask, order,
2305  zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
2306  preferred_zone, migratetype);
2307 
2308  if (!page && gfp_mask & __GFP_NOFAIL)
2309  wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
2310  } while (!page && (gfp_mask & __GFP_NOFAIL));
2311 
2312  return page;
2313 }
2314 
2315 static inline
2316 void wake_all_kswapd(unsigned int order, struct zonelist *zonelist,
2317  enum zone_type high_zoneidx,
2318  enum zone_type classzone_idx)
2319 {
2320  struct zoneref *z;
2321  struct zone *zone;
2322 
2323  for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
2324  wakeup_kswapd(zone, order, classzone_idx);
2325 }
2326 
2327 static inline int
2328 gfp_to_alloc_flags(gfp_t gfp_mask)
2329 {
2330  int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
2331  const gfp_t wait = gfp_mask & __GFP_WAIT;
2332 
2333  /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2334  BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
2335 
2336  /*
2337  * The caller may dip into page reserves a bit more if the caller
2338  * cannot run direct reclaim, or if the caller has realtime scheduling
2339  * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2340  * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
2341  */
2342  alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
2343 
2344  if (!wait) {
2345  /*
2346  * Not worth trying to allocate harder for
2347  * __GFP_NOMEMALLOC even if it can't schedule.
2348  */
2349  if (!(gfp_mask & __GFP_NOMEMALLOC))
2350  alloc_flags |= ALLOC_HARDER;
2351  /*
2352  * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
2353  * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
2354  */
2355  alloc_flags &= ~ALLOC_CPUSET;
2356  } else if (unlikely(rt_task(current)) && !in_interrupt())
2357  alloc_flags |= ALLOC_HARDER;
2358 
2359  if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
2360  if (gfp_mask & __GFP_MEMALLOC)
2361  alloc_flags |= ALLOC_NO_WATERMARKS;
2362  else if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
2363  alloc_flags |= ALLOC_NO_WATERMARKS;
2364  else if (!in_interrupt() &&
2365  ((current->flags & PF_MEMALLOC) ||
2366  unlikely(test_thread_flag(TIF_MEMDIE))))
2367  alloc_flags |= ALLOC_NO_WATERMARKS;
2368  }
2369 #ifdef CONFIG_CMA
2370  if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
2371  alloc_flags |= ALLOC_CMA;
2372 #endif
2373  return alloc_flags;
2374 }
2375 
2377 {
2378  return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS);
2379 }
2380 
2381 static inline struct page *
2382 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
2383  struct zonelist *zonelist, enum zone_type high_zoneidx,
2384  nodemask_t *nodemask, struct zone *preferred_zone,
2385  int migratetype)
2386 {
2387  const gfp_t wait = gfp_mask & __GFP_WAIT;
2388  struct page *page = NULL;
2389  int alloc_flags;
2390  unsigned long pages_reclaimed = 0;
2391  unsigned long did_some_progress;
2392  bool sync_migration = false;
2393  bool deferred_compaction = false;
2394  bool contended_compaction = false;
2395 
2396  /*
2397  * In the slowpath, we sanity check order to avoid ever trying to
2398  * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2399  * be using allocators in order of preference for an area that is
2400  * too large.
2401  */
2402  if (order >= MAX_ORDER) {
2403  WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
2404  return NULL;
2405  }
2406 
2407  /*
2408  * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
2409  * __GFP_NOWARN set) should not cause reclaim since the subsystem
2410  * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
2411  * using a larger set of nodes after it has established that the
2412  * allowed per node queues are empty and that nodes are
2413  * over allocated.
2414  */
2415  if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE)
2416  goto nopage;
2417 
2418 restart:
2419  if (!(gfp_mask & __GFP_NO_KSWAPD))
2420  wake_all_kswapd(order, zonelist, high_zoneidx,
2421  zone_idx(preferred_zone));
2422 
2423  /*
2424  * OK, we're below the kswapd watermark and have kicked background
2425  * reclaim. Now things get more complex, so set up alloc_flags according
2426  * to how we want to proceed.
2427  */
2428  alloc_flags = gfp_to_alloc_flags(gfp_mask);
2429 
2430  /*
2431  * Find the true preferred zone if the allocation is unconstrained by
2432  * cpusets.
2433  */
2434  if (!(alloc_flags & ALLOC_CPUSET) && !nodemask)
2435  first_zones_zonelist(zonelist, high_zoneidx, NULL,
2436  &preferred_zone);
2437 
2438 rebalance:
2439  /* This is the last chance, in general, before the goto nopage. */
2440  page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
2441  high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
2442  preferred_zone, migratetype);
2443  if (page)
2444  goto got_pg;
2445 
2446  /* Allocate without watermarks if the context allows */
2447  if (alloc_flags & ALLOC_NO_WATERMARKS) {
2448  /*
2449  * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
2450  * the allocation is high priority and these type of
2451  * allocations are system rather than user orientated
2452  */
2453  zonelist = node_zonelist(numa_node_id(), gfp_mask);
2454 
2455  page = __alloc_pages_high_priority(gfp_mask, order,
2456  zonelist, high_zoneidx, nodemask,
2457  preferred_zone, migratetype);
2458  if (page) {
2459  goto got_pg;
2460  }
2461  }
2462 
2463  /* Atomic allocations - we can't balance anything */
2464  if (!wait)
2465  goto nopage;
2466 
2467  /* Avoid recursion of direct reclaim */
2468  if (current->flags & PF_MEMALLOC)
2469  goto nopage;
2470 
2471  /* Avoid allocations with no watermarks from looping endlessly */
2472  if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
2473  goto nopage;
2474 
2475  /*
2476  * Try direct compaction. The first pass is asynchronous. Subsequent
2477  * attempts after direct reclaim are synchronous
2478  */
2479  page = __alloc_pages_direct_compact(gfp_mask, order,
2480  zonelist, high_zoneidx,
2481  nodemask,
2482  alloc_flags, preferred_zone,
2483  migratetype, sync_migration,
2484  &contended_compaction,
2485  &deferred_compaction,
2486  &did_some_progress);
2487  if (page)
2488  goto got_pg;
2489  sync_migration = true;
2490 
2491  /*
2492  * If compaction is deferred for high-order allocations, it is because
2493  * sync compaction recently failed. In this is the case and the caller
2494  * requested a movable allocation that does not heavily disrupt the
2495  * system then fail the allocation instead of entering direct reclaim.
2496  */
2497  if ((deferred_compaction || contended_compaction) &&
2498  (gfp_mask & __GFP_NO_KSWAPD))
2499  goto nopage;
2500 
2501  /* Try direct reclaim and then allocating */
2502  page = __alloc_pages_direct_reclaim(gfp_mask, order,
2503  zonelist, high_zoneidx,
2504  nodemask,
2505  alloc_flags, preferred_zone,
2506  migratetype, &did_some_progress);
2507  if (page)
2508  goto got_pg;
2509 
2510  /*
2511  * If we failed to make any progress reclaiming, then we are
2512  * running out of options and have to consider going OOM
2513  */
2514  if (!did_some_progress) {
2515  if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
2516  if (oom_killer_disabled)
2517  goto nopage;
2518  /* Coredumps can quickly deplete all memory reserves */
2519  if ((current->flags & PF_DUMPCORE) &&
2520  !(gfp_mask & __GFP_NOFAIL))
2521  goto nopage;
2522  page = __alloc_pages_may_oom(gfp_mask, order,
2523  zonelist, high_zoneidx,
2524  nodemask, preferred_zone,
2525  migratetype);
2526  if (page)
2527  goto got_pg;
2528 
2529  if (!(gfp_mask & __GFP_NOFAIL)) {
2530  /*
2531  * The oom killer is not called for high-order
2532  * allocations that may fail, so if no progress
2533  * is being made, there are no other options and
2534  * retrying is unlikely to help.
2535  */
2536  if (order > PAGE_ALLOC_COSTLY_ORDER)
2537  goto nopage;
2538  /*
2539  * The oom killer is not called for lowmem
2540  * allocations to prevent needlessly killing
2541  * innocent tasks.
2542  */
2543  if (high_zoneidx < ZONE_NORMAL)
2544  goto nopage;
2545  }
2546 
2547  goto restart;
2548  }
2549  }
2550 
2551  /* Check if we should retry the allocation */
2552  pages_reclaimed += did_some_progress;
2553  if (should_alloc_retry(gfp_mask, order, did_some_progress,
2554  pages_reclaimed)) {
2555  /* Wait for some write requests to complete then retry */
2556  wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
2557  goto rebalance;
2558  } else {
2559  /*
2560  * High-order allocations do not necessarily loop after
2561  * direct reclaim and reclaim/compaction depends on compaction
2562  * being called after reclaim so call directly if necessary
2563  */
2564  page = __alloc_pages_direct_compact(gfp_mask, order,
2565  zonelist, high_zoneidx,
2566  nodemask,
2567  alloc_flags, preferred_zone,
2568  migratetype, sync_migration,
2569  &contended_compaction,
2570  &deferred_compaction,
2571  &did_some_progress);
2572  if (page)
2573  goto got_pg;
2574  }
2575 
2576 nopage:
2577  warn_alloc_failed(gfp_mask, order, NULL);
2578  return page;
2579 got_pg:
2580  if (kmemcheck_enabled)
2581  kmemcheck_pagealloc_alloc(page, order, gfp_mask);
2582 
2583  return page;
2584 }
2585 
2586 /*
2587  * This is the 'heart' of the zoned buddy allocator.
2588  */
2589 struct page *
2590 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
2591  struct zonelist *zonelist, nodemask_t *nodemask)
2592 {
2593  enum zone_type high_zoneidx = gfp_zone(gfp_mask);
2594  struct zone *preferred_zone;
2595  struct page *page = NULL;
2596  int migratetype = allocflags_to_migratetype(gfp_mask);
2597  unsigned int cpuset_mems_cookie;
2598  int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET;
2599 
2600  gfp_mask &= gfp_allowed_mask;
2601 
2602  lockdep_trace_alloc(gfp_mask);
2603 
2604  might_sleep_if(gfp_mask & __GFP_WAIT);
2605 
2606  if (should_fail_alloc_page(gfp_mask, order))
2607  return NULL;
2608 
2609  /*
2610  * Check the zones suitable for the gfp_mask contain at least one
2611  * valid zone. It's possible to have an empty zonelist as a result
2612  * of GFP_THISNODE and a memoryless node
2613  */
2614  if (unlikely(!zonelist->_zonerefs->zone))
2615  return NULL;
2616 
2617 retry_cpuset:
2618  cpuset_mems_cookie = get_mems_allowed();
2619 
2620  /* The preferred zone is used for statistics later */
2621  first_zones_zonelist(zonelist, high_zoneidx,
2622  nodemask ? : &cpuset_current_mems_allowed,
2623  &preferred_zone);
2624  if (!preferred_zone)
2625  goto out;
2626 
2627 #ifdef CONFIG_CMA
2628  if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
2629  alloc_flags |= ALLOC_CMA;
2630 #endif
2631  /* First allocation attempt */
2632  page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
2633  zonelist, high_zoneidx, alloc_flags,
2634  preferred_zone, migratetype);
2635  if (unlikely(!page))
2636  page = __alloc_pages_slowpath(gfp_mask, order,
2637  zonelist, high_zoneidx, nodemask,
2638  preferred_zone, migratetype);
2639 
2640  trace_mm_page_alloc(page, order, gfp_mask, migratetype);
2641 
2642 out:
2643  /*
2644  * When updating a task's mems_allowed, it is possible to race with
2645  * parallel threads in such a way that an allocation can fail while
2646  * the mask is being updated. If a page allocation is about to fail,
2647  * check if the cpuset changed during allocation and if so, retry.
2648  */
2649  if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
2650  goto retry_cpuset;
2651 
2652  return page;
2653 }
2655 
2656 /*
2657  * Common helper functions.
2658  */
2659 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
2660 {
2661  struct page *page;
2662 
2663  /*
2664  * __get_free_pages() returns a 32-bit address, which cannot represent
2665  * a highmem page
2666  */
2667  VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
2668 
2669  page = alloc_pages(gfp_mask, order);
2670  if (!page)
2671  return 0;
2672  return (unsigned long) page_address(page);
2673 }
2675 
2676 unsigned long get_zeroed_page(gfp_t gfp_mask)
2677 {
2678  return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
2679 }
2681 
2682 void __free_pages(struct page *page, unsigned int order)
2683 {
2684  if (put_page_testzero(page)) {
2685  if (order == 0)
2686  free_hot_cold_page(page, 0);
2687  else
2688  __free_pages_ok(page, order);
2689  }
2690 }
2691 
2693 
2694 void free_pages(unsigned long addr, unsigned int order)
2695 {
2696  if (addr != 0) {
2697  VM_BUG_ON(!virt_addr_valid((void *)addr));
2698  __free_pages(virt_to_page((void *)addr), order);
2699  }
2700 }
2701 
2702 EXPORT_SYMBOL(free_pages);
2703 
2704 static void *make_alloc_exact(unsigned long addr, unsigned order, size_t size)
2705 {
2706  if (addr) {
2707  unsigned long alloc_end = addr + (PAGE_SIZE << order);
2708  unsigned long used = addr + PAGE_ALIGN(size);
2709 
2710  split_page(virt_to_page((void *)addr), order);
2711  while (used < alloc_end) {
2712  free_page(used);
2713  used += PAGE_SIZE;
2714  }
2715  }
2716  return (void *)addr;
2717 }
2718 
2732 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
2733 {
2734  unsigned int order = get_order(size);
2735  unsigned long addr;
2736 
2737  addr = __get_free_pages(gfp_mask, order);
2738  return make_alloc_exact(addr, order, size);
2739 }
2741 
2754 void *alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
2755 {
2756  unsigned order = get_order(size);
2757  struct page *p = alloc_pages_node(nid, gfp_mask, order);
2758  if (!p)
2759  return NULL;
2760  return make_alloc_exact((unsigned long)page_address(p), order, size);
2761 }
2763 
2771 void free_pages_exact(void *virt, size_t size)
2772 {
2773  unsigned long addr = (unsigned long)virt;
2774  unsigned long end = addr + PAGE_ALIGN(size);
2775 
2776  while (addr < end) {
2777  free_page(addr);
2778  addr += PAGE_SIZE;
2779  }
2780 }
2782 
2783 static unsigned int nr_free_zone_pages(int offset)
2784 {
2785  struct zoneref *z;
2786  struct zone *zone;
2787 
2788  /* Just pick one node, since fallback list is circular */
2789  unsigned int sum = 0;
2790 
2791  struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
2792 
2793  for_each_zone_zonelist(zone, z, zonelist, offset) {
2794  unsigned long size = zone->present_pages;
2795  unsigned long high = high_wmark_pages(zone);
2796  if (size > high)
2797  sum += size - high;
2798  }
2799 
2800  return sum;
2801 }
2802 
2803 /*
2804  * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
2805  */
2806 unsigned int nr_free_buffer_pages(void)
2807 {
2808  return nr_free_zone_pages(gfp_zone(GFP_USER));
2809 }
2811 
2812 /*
2813  * Amount of free RAM allocatable within all zones
2814  */
2815 unsigned int nr_free_pagecache_pages(void)
2816 {
2817  return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
2818 }
2819 
2820 static inline void show_node(struct zone *zone)
2821 {
2822  if (NUMA_BUILD)
2823  printk("Node %d ", zone_to_nid(zone));
2824 }
2825 
2826 void si_meminfo(struct sysinfo *val)
2827 {
2828  val->totalram = totalram_pages;
2829  val->sharedram = 0;
2830  val->freeram = global_page_state(NR_FREE_PAGES);
2831  val->bufferram = nr_blockdev_pages();
2832  val->totalhigh = totalhigh_pages;
2833  val->freehigh = nr_free_highpages();
2834  val->mem_unit = PAGE_SIZE;
2835 }
2836 
2838 
2839 #ifdef CONFIG_NUMA
2840 void si_meminfo_node(struct sysinfo *val, int nid)
2841 {
2842  pg_data_t *pgdat = NODE_DATA(nid);
2843 
2844  val->totalram = pgdat->node_present_pages;
2845  val->freeram = node_page_state(nid, NR_FREE_PAGES);
2846 #ifdef CONFIG_HIGHMEM
2847  val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
2848  val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
2849  NR_FREE_PAGES);
2850 #else
2851  val->totalhigh = 0;
2852  val->freehigh = 0;
2853 #endif
2854  val->mem_unit = PAGE_SIZE;
2855 }
2856 #endif
2857 
2858 /*
2859  * Determine whether the node should be displayed or not, depending on whether
2860  * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
2861  */
2862 bool skip_free_areas_node(unsigned int flags, int nid)
2863 {
2864  bool ret = false;
2865  unsigned int cpuset_mems_cookie;
2866 
2867  if (!(flags & SHOW_MEM_FILTER_NODES))
2868  goto out;
2869 
2870  do {
2871  cpuset_mems_cookie = get_mems_allowed();
2873  } while (!put_mems_allowed(cpuset_mems_cookie));
2874 out:
2875  return ret;
2876 }
2877 
2878 #define K(x) ((x) << (PAGE_SHIFT-10))
2879 
2880 /*
2881  * Show free area list (used inside shift_scroll-lock stuff)
2882  * We also calculate the percentage fragmentation. We do this by counting the
2883  * memory on each free list with the exception of the first item on the list.
2884  * Suppresses nodes that are not allowed by current's cpuset if
2885  * SHOW_MEM_FILTER_NODES is passed.
2886  */
2887 void show_free_areas(unsigned int filter)
2888 {
2889  int cpu;
2890  struct zone *zone;
2891 
2892  for_each_populated_zone(zone) {
2893  if (skip_free_areas_node(filter, zone_to_nid(zone)))
2894  continue;
2895  show_node(zone);
2896  printk("%s per-cpu:\n", zone->name);
2897 
2898  for_each_online_cpu(cpu) {
2899  struct per_cpu_pageset *pageset;
2900 
2901  pageset = per_cpu_ptr(zone->pageset, cpu);
2902 
2903  printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
2904  cpu, pageset->pcp.high,
2905  pageset->pcp.batch, pageset->pcp.count);
2906  }
2907  }
2908 
2909  printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
2910  " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
2911  " unevictable:%lu"
2912  " dirty:%lu writeback:%lu unstable:%lu\n"
2913  " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2914  " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
2915  " free_cma:%lu\n",
2916  global_page_state(NR_ACTIVE_ANON),
2917  global_page_state(NR_INACTIVE_ANON),
2918  global_page_state(NR_ISOLATED_ANON),
2919  global_page_state(NR_ACTIVE_FILE),
2920  global_page_state(NR_INACTIVE_FILE),
2921  global_page_state(NR_ISOLATED_FILE),
2922  global_page_state(NR_UNEVICTABLE),
2923  global_page_state(NR_FILE_DIRTY),
2924  global_page_state(NR_WRITEBACK),
2925  global_page_state(NR_UNSTABLE_NFS),
2926  global_page_state(NR_FREE_PAGES),
2927  global_page_state(NR_SLAB_RECLAIMABLE),
2928  global_page_state(NR_SLAB_UNRECLAIMABLE),
2929  global_page_state(NR_FILE_MAPPED),
2930  global_page_state(NR_SHMEM),
2931  global_page_state(NR_PAGETABLE),
2932  global_page_state(NR_BOUNCE),
2933  global_page_state(NR_FREE_CMA_PAGES));
2934 
2935  for_each_populated_zone(zone) {
2936  int i;
2937 
2938  if (skip_free_areas_node(filter, zone_to_nid(zone)))
2939  continue;
2940  show_node(zone);
2941  printk("%s"
2942  " free:%lukB"
2943  " min:%lukB"
2944  " low:%lukB"
2945  " high:%lukB"
2946  " active_anon:%lukB"
2947  " inactive_anon:%lukB"
2948  " active_file:%lukB"
2949  " inactive_file:%lukB"
2950  " unevictable:%lukB"
2951  " isolated(anon):%lukB"
2952  " isolated(file):%lukB"
2953  " present:%lukB"
2954  " mlocked:%lukB"
2955  " dirty:%lukB"
2956  " writeback:%lukB"
2957  " mapped:%lukB"
2958  " shmem:%lukB"
2959  " slab_reclaimable:%lukB"
2960  " slab_unreclaimable:%lukB"
2961  " kernel_stack:%lukB"
2962  " pagetables:%lukB"
2963  " unstable:%lukB"
2964  " bounce:%lukB"
2965  " free_cma:%lukB"
2966  " writeback_tmp:%lukB"
2967  " pages_scanned:%lu"
2968  " all_unreclaimable? %s"
2969  "\n",
2970  zone->name,
2971  K(zone_page_state(zone, NR_FREE_PAGES)),
2972  K(min_wmark_pages(zone)),
2973  K(low_wmark_pages(zone)),
2974  K(high_wmark_pages(zone)),
2975  K(zone_page_state(zone, NR_ACTIVE_ANON)),
2976  K(zone_page_state(zone, NR_INACTIVE_ANON)),
2977  K(zone_page_state(zone, NR_ACTIVE_FILE)),
2978  K(zone_page_state(zone, NR_INACTIVE_FILE)),
2979  K(zone_page_state(zone, NR_UNEVICTABLE)),
2980  K(zone_page_state(zone, NR_ISOLATED_ANON)),
2981  K(zone_page_state(zone, NR_ISOLATED_FILE)),
2982  K(zone->present_pages),
2983  K(zone_page_state(zone, NR_MLOCK)),
2984  K(zone_page_state(zone, NR_FILE_DIRTY)),
2985  K(zone_page_state(zone, NR_WRITEBACK)),
2986  K(zone_page_state(zone, NR_FILE_MAPPED)),
2987  K(zone_page_state(zone, NR_SHMEM)),
2988  K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
2989  K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
2990  zone_page_state(zone, NR_KERNEL_STACK) *
2991  THREAD_SIZE / 1024,
2992  K(zone_page_state(zone, NR_PAGETABLE)),
2993  K(zone_page_state(zone, NR_UNSTABLE_NFS)),
2994  K(zone_page_state(zone, NR_BOUNCE)),
2995  K(zone_page_state(zone, NR_FREE_CMA_PAGES)),
2996  K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
2997  zone->pages_scanned,
2998  (zone->all_unreclaimable ? "yes" : "no")
2999  );
3000  printk("lowmem_reserve[]:");
3001  for (i = 0; i < MAX_NR_ZONES; i++)
3002  printk(" %lu", zone->lowmem_reserve[i]);
3003  printk("\n");
3004  }
3005 
3006  for_each_populated_zone(zone) {
3007  unsigned long nr[MAX_ORDER], flags, order, total = 0;
3008 
3009  if (skip_free_areas_node(filter, zone_to_nid(zone)))
3010  continue;
3011  show_node(zone);
3012  printk("%s: ", zone->name);
3013 
3014  spin_lock_irqsave(&zone->lock, flags);
3015  for (order = 0; order < MAX_ORDER; order++) {
3016  nr[order] = zone->free_area[order].nr_free;
3017  total += nr[order] << order;
3018  }
3019  spin_unlock_irqrestore(&zone->lock, flags);
3020  for (order = 0; order < MAX_ORDER; order++)
3021  printk("%lu*%lukB ", nr[order], K(1UL) << order);
3022  printk("= %lukB\n", K(total));
3023  }
3024 
3025  printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
3026 
3028 }
3029 
3030 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
3031 {
3032  zoneref->zone = zone;
3033  zoneref->zone_idx = zone_idx(zone);
3034 }
3035 
3036 /*
3037  * Builds allocation fallback zone lists.
3038  *
3039  * Add all populated zones of a node to the zonelist.
3040  */
3041 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
3042  int nr_zones, enum zone_type zone_type)
3043 {
3044  struct zone *zone;
3045 
3046  BUG_ON(zone_type >= MAX_NR_ZONES);
3047  zone_type++;
3048 
3049  do {
3050  zone_type--;
3051  zone = pgdat->node_zones + zone_type;
3052  if (populated_zone(zone)) {
3053  zoneref_set_zone(zone,
3054  &zonelist->_zonerefs[nr_zones++]);
3055  check_highest_zone(zone_type);
3056  }
3057 
3058  } while (zone_type);
3059  return nr_zones;
3060 }
3061 
3062 
3063 /*
3064  * zonelist_order:
3065  * 0 = automatic detection of better ordering.
3066  * 1 = order by ([node] distance, -zonetype)
3067  * 2 = order by (-zonetype, [node] distance)
3068  *
3069  * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
3070  * the same zonelist. So only NUMA can configure this param.
3071  */
3072 #define ZONELIST_ORDER_DEFAULT 0
3073 #define ZONELIST_ORDER_NODE 1
3074 #define ZONELIST_ORDER_ZONE 2
3075 
3076 /* zonelist order in the kernel.
3077  * set_zonelist_order() will set this to NODE or ZONE.
3078  */
3079 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
3080 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
3081 
3082 
3083 #ifdef CONFIG_NUMA
3084 /* The value user specified ....changed by config */
3085 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
3086 /* string for sysctl */
3087 #define NUMA_ZONELIST_ORDER_LEN 16
3088 char numa_zonelist_order[16] = "default";
3089 
3090 /*
3091  * interface for configure zonelist ordering.
3092  * command line option "numa_zonelist_order"
3093  * = "[dD]efault - default, automatic configuration.
3094  * = "[nN]ode - order by node locality, then by zone within node
3095  * = "[zZ]one - order by zone, then by locality within zone
3096  */
3097 
3098 static int __parse_numa_zonelist_order(char *s)
3099 {
3100  if (*s == 'd' || *s == 'D') {
3101  user_zonelist_order = ZONELIST_ORDER_DEFAULT;
3102  } else if (*s == 'n' || *s == 'N') {
3103  user_zonelist_order = ZONELIST_ORDER_NODE;
3104  } else if (*s == 'z' || *s == 'Z') {
3105  user_zonelist_order = ZONELIST_ORDER_ZONE;
3106  } else {
3108  "Ignoring invalid numa_zonelist_order value: "
3109  "%s\n", s);
3110  return -EINVAL;
3111  }
3112  return 0;
3113 }
3114 
3115 static __init int setup_numa_zonelist_order(char *s)
3116 {
3117  int ret;
3118 
3119  if (!s)
3120  return 0;
3121 
3122  ret = __parse_numa_zonelist_order(s);
3123  if (ret == 0)
3124  strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
3125 
3126  return ret;
3127 }
3128 early_param("numa_zonelist_order", setup_numa_zonelist_order);
3129 
3130 /*
3131  * sysctl handler for numa_zonelist_order
3132  */
3134  void __user *buffer, size_t *length,
3135  loff_t *ppos)
3136 {
3137  char saved_string[NUMA_ZONELIST_ORDER_LEN];
3138  int ret;
3139  static DEFINE_MUTEX(zl_order_mutex);
3140 
3141  mutex_lock(&zl_order_mutex);
3142  if (write)
3143  strcpy(saved_string, (char*)table->data);
3144  ret = proc_dostring(table, write, buffer, length, ppos);
3145  if (ret)
3146  goto out;
3147  if (write) {
3148  int oldval = user_zonelist_order;
3149  if (__parse_numa_zonelist_order((char*)table->data)) {
3150  /*
3151  * bogus value. restore saved string
3152  */
3153  strncpy((char*)table->data, saved_string,
3155  user_zonelist_order = oldval;
3156  } else if (oldval != user_zonelist_order) {
3157  mutex_lock(&zonelists_mutex);
3159  mutex_unlock(&zonelists_mutex);
3160  }
3161  }
3162 out:
3163  mutex_unlock(&zl_order_mutex);
3164  return ret;
3165 }
3166 
3167 
3168 #define MAX_NODE_LOAD (nr_online_nodes)
3169 static int node_load[MAX_NUMNODES];
3170 
3185 static int find_next_best_node(int node, nodemask_t *used_node_mask)
3186 {
3187  int n, val;
3188  int min_val = INT_MAX;
3189  int best_node = -1;
3190  const struct cpumask *tmp = cpumask_of_node(0);
3191 
3192  /* Use the local node if we haven't already */
3193  if (!node_isset(node, *used_node_mask)) {
3194  node_set(node, *used_node_mask);
3195  return node;
3196  }
3197 
3199 
3200  /* Don't want a node to appear more than once */
3201  if (node_isset(n, *used_node_mask))
3202  continue;
3203 
3204  /* Use the distance array to find the distance */
3205  val = node_distance(node, n);
3206 
3207  /* Penalize nodes under us ("prefer the next node") */
3208  val += (n < node);
3209 
3210  /* Give preference to headless and unused nodes */
3211  tmp = cpumask_of_node(n);
3212  if (!cpumask_empty(tmp))
3214 
3215  /* Slight preference for less loaded node */
3216  val *= (MAX_NODE_LOAD*MAX_NUMNODES);
3217  val += node_load[n];
3218 
3219  if (val < min_val) {
3220  min_val = val;
3221  best_node = n;
3222  }
3223  }
3224 
3225  if (best_node >= 0)
3226  node_set(best_node, *used_node_mask);
3227 
3228  return best_node;
3229 }
3230 
3231 
3232 /*
3233  * Build zonelists ordered by node and zones within node.
3234  * This results in maximum locality--normal zone overflows into local
3235  * DMA zone, if any--but risks exhausting DMA zone.
3236  */
3237 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
3238 {
3239  int j;
3240  struct zonelist *zonelist;
3241 
3242  zonelist = &pgdat->node_zonelists[0];
3243  for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
3244  ;
3245  j = build_zonelists_node(NODE_DATA(node), zonelist, j,
3246  MAX_NR_ZONES - 1);
3247  zonelist->_zonerefs[j].zone = NULL;
3248  zonelist->_zonerefs[j].zone_idx = 0;
3249 }
3250 
3251 /*
3252  * Build gfp_thisnode zonelists
3253  */
3254 static void build_thisnode_zonelists(pg_data_t *pgdat)
3255 {
3256  int j;
3257  struct zonelist *zonelist;
3258 
3259  zonelist = &pgdat->node_zonelists[1];
3260  j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
3261  zonelist->_zonerefs[j].zone = NULL;
3262  zonelist->_zonerefs[j].zone_idx = 0;
3263 }
3264 
3265 /*
3266  * Build zonelists ordered by zone and nodes within zones.
3267  * This results in conserving DMA zone[s] until all Normal memory is
3268  * exhausted, but results in overflowing to remote node while memory
3269  * may still exist in local DMA zone.
3270  */
3271 static int node_order[MAX_NUMNODES];
3272 
3273 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
3274 {
3275  int pos, j, node;
3276  int zone_type; /* needs to be signed */
3277  struct zone *z;
3278  struct zonelist *zonelist;
3279 
3280  zonelist = &pgdat->node_zonelists[0];
3281  pos = 0;
3282  for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
3283  for (j = 0; j < nr_nodes; j++) {
3284  node = node_order[j];
3285  z = &NODE_DATA(node)->node_zones[zone_type];
3286  if (populated_zone(z)) {
3287  zoneref_set_zone(z,
3288  &zonelist->_zonerefs[pos++]);
3289  check_highest_zone(zone_type);
3290  }
3291  }
3292  }
3293  zonelist->_zonerefs[pos].zone = NULL;
3294  zonelist->_zonerefs[pos].zone_idx = 0;
3295 }
3296 
3297 static int default_zonelist_order(void)
3298 {
3299  int nid, zone_type;
3300  unsigned long low_kmem_size,total_size;
3301  struct zone *z;
3302  int average_size;
3303  /*
3304  * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
3305  * If they are really small and used heavily, the system can fall
3306  * into OOM very easily.
3307  * This function detect ZONE_DMA/DMA32 size and configures zone order.
3308  */
3309  /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
3310  low_kmem_size = 0;
3311  total_size = 0;
3312  for_each_online_node(nid) {
3313  for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
3314  z = &NODE_DATA(nid)->node_zones[zone_type];
3315  if (populated_zone(z)) {
3316  if (zone_type < ZONE_NORMAL)
3317  low_kmem_size += z->present_pages;
3318  total_size += z->present_pages;
3319  } else if (zone_type == ZONE_NORMAL) {
3320  /*
3321  * If any node has only lowmem, then node order
3322  * is preferred to allow kernel allocations
3323  * locally; otherwise, they can easily infringe
3324  * on other nodes when there is an abundance of
3325  * lowmem available to allocate from.
3326  */
3327  return ZONELIST_ORDER_NODE;
3328  }
3329  }
3330  }
3331  if (!low_kmem_size || /* there are no DMA area. */
3332  low_kmem_size > total_size/2) /* DMA/DMA32 is big. */
3333  return ZONELIST_ORDER_NODE;
3334  /*
3335  * look into each node's config.
3336  * If there is a node whose DMA/DMA32 memory is very big area on
3337  * local memory, NODE_ORDER may be suitable.
3338  */
3339  average_size = total_size /
3341  for_each_online_node(nid) {
3342  low_kmem_size = 0;
3343  total_size = 0;
3344  for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
3345  z = &NODE_DATA(nid)->node_zones[zone_type];
3346  if (populated_zone(z)) {
3347  if (zone_type < ZONE_NORMAL)
3348  low_kmem_size += z->present_pages;
3349  total_size += z->present_pages;
3350  }
3351  }
3352  if (low_kmem_size &&
3353  total_size > average_size && /* ignore small node */
3354  low_kmem_size > total_size * 70/100)
3355  return ZONELIST_ORDER_NODE;
3356  }
3357  return ZONELIST_ORDER_ZONE;
3358 }
3359 
3360 static void set_zonelist_order(void)
3361 {
3362  if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
3363  current_zonelist_order = default_zonelist_order();
3364  else
3365  current_zonelist_order = user_zonelist_order;
3366 }
3367 
3368 static void build_zonelists(pg_data_t *pgdat)
3369 {
3370  int j, node, load;
3371  enum zone_type i;
3372  nodemask_t used_mask;
3373  int local_node, prev_node;
3374  struct zonelist *zonelist;
3375  int order = current_zonelist_order;
3376 
3377  /* initialize zonelists */
3378  for (i = 0; i < MAX_ZONELISTS; i++) {
3379  zonelist = pgdat->node_zonelists + i;
3380  zonelist->_zonerefs[0].zone = NULL;
3381  zonelist->_zonerefs[0].zone_idx = 0;
3382  }
3383 
3384  /* NUMA-aware ordering of nodes */
3385  local_node = pgdat->node_id;
3386  load = nr_online_nodes;
3387  prev_node = local_node;
3388  nodes_clear(used_mask);
3389 
3390  memset(node_order, 0, sizeof(node_order));
3391  j = 0;
3392 
3393  while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
3394  /*
3395  * We don't want to pressure a particular node.
3396  * So adding penalty to the first node in same
3397  * distance group to make it round-robin.
3398  */
3399  if (node_distance(local_node, node) !=
3400  node_distance(local_node, prev_node))
3401  node_load[node] = load;
3402 
3403  prev_node = node;
3404  load--;
3405  if (order == ZONELIST_ORDER_NODE)
3406  build_zonelists_in_node_order(pgdat, node);
3407  else
3408  node_order[j++] = node; /* remember order */
3409  }
3410 
3411  if (order == ZONELIST_ORDER_ZONE) {
3412  /* calculate node order -- i.e., DMA last! */
3413  build_zonelists_in_zone_order(pgdat, j);
3414  }
3415 
3416  build_thisnode_zonelists(pgdat);
3417 }
3418 
3419 /* Construct the zonelist performance cache - see further mmzone.h */
3420 static void build_zonelist_cache(pg_data_t *pgdat)
3421 {
3422  struct zonelist *zonelist;
3423  struct zonelist_cache *zlc;
3424  struct zoneref *z;
3425 
3426  zonelist = &pgdat->node_zonelists[0];
3427  zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
3428  bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
3429  for (z = zonelist->_zonerefs; z->zone; z++)
3430  zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
3431 }
3432 
3433 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3434 /*
3435  * Return node id of node used for "local" allocations.
3436  * I.e., first node id of first zone in arg node's generic zonelist.
3437  * Used for initializing percpu 'numa_mem', which is used primarily
3438  * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
3439  */
3440 int local_memory_node(int node)
3441 {
3442  struct zone *zone;
3443 
3444  (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
3445  gfp_zone(GFP_KERNEL),
3446  NULL,
3447  &zone);
3448  return zone->node;
3449 }
3450 #endif
3451 
3452 #else /* CONFIG_NUMA */
3453 
3454 static void set_zonelist_order(void)
3455 {
3456  current_zonelist_order = ZONELIST_ORDER_ZONE;
3457 }
3458 
3459 static void build_zonelists(pg_data_t *pgdat)
3460 {
3461  int node, local_node;
3462  enum zone_type j;
3463  struct zonelist *zonelist;
3464 
3465  local_node = pgdat->node_id;
3466 
3467  zonelist = &pgdat->node_zonelists[0];
3468  j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
3469 
3470  /*
3471  * Now we build the zonelist so that it contains the zones
3472  * of all the other nodes.
3473  * We don't want to pressure a particular node, so when
3474  * building the zones for node N, we make sure that the
3475  * zones coming right after the local ones are those from
3476  * node N+1 (modulo N)
3477  */
3478  for (node = local_node + 1; node < MAX_NUMNODES; node++) {
3479  if (!node_online(node))
3480  continue;
3481  j = build_zonelists_node(NODE_DATA(node), zonelist, j,
3482  MAX_NR_ZONES - 1);
3483  }
3484  for (node = 0; node < local_node; node++) {
3485  if (!node_online(node))
3486  continue;
3487  j = build_zonelists_node(NODE_DATA(node), zonelist, j,
3488  MAX_NR_ZONES - 1);
3489  }
3490 
3491  zonelist->_zonerefs[j].zone = NULL;
3492  zonelist->_zonerefs[j].zone_idx = 0;
3493 }
3494 
3495 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3496 static void build_zonelist_cache(pg_data_t *pgdat)
3497 {
3498  pgdat->node_zonelists[0].zlcache_ptr = NULL;
3499 }
3500 
3501 #endif /* CONFIG_NUMA */
3502 
3503 /*
3504  * Boot pageset table. One per cpu which is going to be used for all
3505  * zones and all nodes. The parameters will be set in such a way
3506  * that an item put on a list will immediately be handed over to
3507  * the buddy list. This is safe since pageset manipulation is done
3508  * with interrupts disabled.
3509  *
3510  * The boot_pagesets must be kept even after bootup is complete for
3511  * unused processors and/or zones. They do play a role for bootstrapping
3512  * hotplugged processors.
3513  *
3514  * zoneinfo_show() and maybe other functions do
3515  * not check if the processor is online before following the pageset pointer.
3516  * Other parts of the kernel may not check if the zone is available.
3517  */
3518 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
3519 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
3520 static void setup_zone_pageset(struct zone *zone);
3521 
3522 /*
3523  * Global mutex to protect against size modification of zonelists
3524  * as well as to serialize pageset setup for the new populated zone.
3525  */
3526 DEFINE_MUTEX(zonelists_mutex);
3527 
3528 /* return values int ....just for stop_machine() */
3529 static int __build_all_zonelists(void *data)
3530 {
3531  int nid;
3532  int cpu;
3533  pg_data_t *self = data;
3534 
3535 #ifdef CONFIG_NUMA
3536  memset(node_load, 0, sizeof(node_load));
3537 #endif
3538 
3539  if (self && !node_online(self->node_id)) {
3540  build_zonelists(self);
3541  build_zonelist_cache(self);
3542  }
3543 
3544  for_each_online_node(nid) {
3545  pg_data_t *pgdat = NODE_DATA(nid);
3546 
3547  build_zonelists(pgdat);
3548  build_zonelist_cache(pgdat);
3549  }
3550 
3551  /*
3552  * Initialize the boot_pagesets that are going to be used
3553  * for bootstrapping processors. The real pagesets for
3554  * each zone will be allocated later when the per cpu
3555  * allocator is available.
3556  *
3557  * boot_pagesets are used also for bootstrapping offline
3558  * cpus if the system is already booted because the pagesets
3559  * are needed to initialize allocators on a specific cpu too.
3560  * F.e. the percpu allocator needs the page allocator which
3561  * needs the percpu allocator in order to allocate its pagesets
3562  * (a chicken-egg dilemma).
3563  */
3564  for_each_possible_cpu(cpu) {
3565  setup_pageset(&per_cpu(boot_pageset, cpu), 0);
3566 
3567 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3568  /*
3569  * We now know the "local memory node" for each node--
3570  * i.e., the node of the first zone in the generic zonelist.
3571  * Set up numa_mem percpu variable for on-line cpus. During
3572  * boot, only the boot cpu should be on-line; we'll init the
3573  * secondary cpus' numa_mem as they come on-line. During
3574  * node/memory hotplug, we'll fixup all on-line cpus.
3575  */
3576  if (cpu_online(cpu))
3577  set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
3578 #endif
3579  }
3580 
3581  return 0;
3582 }
3583 
3584 /*
3585  * Called with zonelists_mutex held always
3586  * unless system_state == SYSTEM_BOOTING.
3587  */
3588 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
3589 {
3590  set_zonelist_order();
3591 
3592  if (system_state == SYSTEM_BOOTING) {
3593  __build_all_zonelists(NULL);
3594  mminit_verify_zonelist();
3596  } else {
3597  /* we have to stop all cpus to guarantee there is no user
3598  of zonelist */
3599 #ifdef CONFIG_MEMORY_HOTPLUG
3600  if (zone)
3601  setup_zone_pageset(zone);
3602 #endif
3603  stop_machine(__build_all_zonelists, pgdat, NULL);
3604  /* cpuset refresh routine should be here */
3605  }
3607  /*
3608  * Disable grouping by mobility if the number of pages in the
3609  * system is too low to allow the mechanism to work. It would be
3610  * more accurate, but expensive to check per-zone. This check is
3611  * made on memory-hotadd so a system can start with mobility
3612  * disabled and enable it later
3613  */
3616  else
3618 
3619  printk("Built %i zonelists in %s order, mobility grouping %s. "
3620  "Total pages: %ld\n",
3622  zonelist_order_name[current_zonelist_order],
3623  page_group_by_mobility_disabled ? "off" : "on",
3624  vm_total_pages);
3625 #ifdef CONFIG_NUMA
3626  printk("Policy zone: %s\n", zone_names[policy_zone]);
3627 #endif
3628 }
3629 
3630 /*
3631  * Helper functions to size the waitqueue hash table.
3632  * Essentially these want to choose hash table sizes sufficiently
3633  * large so that collisions trying to wait on pages are rare.
3634  * But in fact, the number of active page waitqueues on typical
3635  * systems is ridiculously low, less than 200. So this is even
3636  * conservative, even though it seems large.
3637  *
3638  * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
3639  * waitqueues, i.e. the size of the waitq table given the number of pages.
3640  */
3641 #define PAGES_PER_WAITQUEUE 256
3642 
3643 #ifndef CONFIG_MEMORY_HOTPLUG
3644 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
3645 {
3646  unsigned long size = 1;
3647 
3648  pages /= PAGES_PER_WAITQUEUE;
3649 
3650  while (size < pages)
3651  size <<= 1;
3652 
3653  /*
3654  * Once we have dozens or even hundreds of threads sleeping
3655  * on IO we've got bigger problems than wait queue collision.
3656  * Limit the size of the wait table to a reasonable size.
3657  */
3658  size = min(size, 4096UL);
3659 
3660  return max(size, 4UL);
3661 }
3662 #else
3663 /*
3664  * A zone's size might be changed by hot-add, so it is not possible to determine
3665  * a suitable size for its wait_table. So we use the maximum size now.
3666  *
3667  * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
3668  *
3669  * i386 (preemption config) : 4096 x 16 = 64Kbyte.
3670  * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
3671  * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
3672  *
3673  * The maximum entries are prepared when a zone's memory is (512K + 256) pages
3674  * or more by the traditional way. (See above). It equals:
3675  *
3676  * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
3677  * ia64(16K page size) : = ( 8G + 4M)byte.
3678  * powerpc (64K page size) : = (32G +16M)byte.
3679  */
3680 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
3681 {
3682  return 4096UL;
3683 }
3684 #endif
3685 
3686 /*
3687  * This is an integer logarithm so that shifts can be used later
3688  * to extract the more random high bits from the multiplicative
3689  * hash function before the remainder is taken.
3690  */
3691 static inline unsigned long wait_table_bits(unsigned long size)
3692 {
3693  return ffz(~size);
3694 }
3695 
3696 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
3697 
3698 /*
3699  * Check if a pageblock contains reserved pages
3700  */
3701 static int pageblock_is_reserved(unsigned long start_pfn, unsigned long end_pfn)
3702 {
3703  unsigned long pfn;
3704 
3705  for (pfn = start_pfn; pfn < end_pfn; pfn++) {
3706  if (!pfn_valid_within(pfn) || PageReserved(pfn_to_page(pfn)))
3707  return 1;
3708  }
3709  return 0;
3710 }
3711 
3712 /*
3713  * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3714  * of blocks reserved is based on min_wmark_pages(zone). The memory within
3715  * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
3716  * higher will lead to a bigger reserve which will get freed as contiguous
3717  * blocks as reclaim kicks in
3718  */
3719 static void setup_zone_migrate_reserve(struct zone *zone)
3720 {
3721  unsigned long start_pfn, pfn, end_pfn, block_end_pfn;
3722  struct page *page;
3723  unsigned long block_migratetype;
3724  int reserve;
3725 
3726  /*
3727  * Get the start pfn, end pfn and the number of blocks to reserve
3728  * We have to be careful to be aligned to pageblock_nr_pages to
3729  * make sure that we always check pfn_valid for the first page in
3730  * the block.
3731  */
3732  start_pfn = zone->zone_start_pfn;
3733  end_pfn = start_pfn + zone->spanned_pages;
3734  start_pfn = roundup(start_pfn, pageblock_nr_pages);
3735  reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
3737 
3738  /*
3739  * Reserve blocks are generally in place to help high-order atomic
3740  * allocations that are short-lived. A min_free_kbytes value that
3741  * would result in more than 2 reserve blocks for atomic allocations
3742  * is assumed to be in place to help anti-fragmentation for the
3743  * future allocation of hugepages at runtime.
3744  */
3745  reserve = min(2, reserve);
3746 
3747  for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
3748  if (!pfn_valid(pfn))
3749  continue;
3750  page = pfn_to_page(pfn);
3751 
3752  /* Watch out for overlapping nodes */
3753  if (page_to_nid(page) != zone_to_nid(zone))
3754  continue;
3755 
3756  block_migratetype = get_pageblock_migratetype(page);
3757 
3758  /* Only test what is necessary when the reserves are not met */
3759  if (reserve > 0) {
3760  /*
3761  * Blocks with reserved pages will never free, skip
3762  * them.
3763  */
3764  block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn);
3765  if (pageblock_is_reserved(pfn, block_end_pfn))
3766  continue;
3767 
3768  /* If this block is reserved, account for it */
3769  if (block_migratetype == MIGRATE_RESERVE) {
3770  reserve--;
3771  continue;
3772  }
3773 
3774  /* Suitable for reserving if this block is movable */
3775  if (block_migratetype == MIGRATE_MOVABLE) {
3777  MIGRATE_RESERVE);
3778  move_freepages_block(zone, page,
3779  MIGRATE_RESERVE);
3780  reserve--;
3781  continue;
3782  }
3783  }
3784 
3785  /*
3786  * If the reserve is met and this is a previous reserved block,
3787  * take it back
3788  */
3789  if (block_migratetype == MIGRATE_RESERVE) {
3792  }
3793  }
3794 }
3795 
3796 /*
3797  * Initially all pages are reserved - free ones are freed
3798  * up by free_all_bootmem() once the early boot process is
3799  * done. Non-atomic initialization, single-pass.
3800  */
3801 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
3802  unsigned long start_pfn, enum memmap_context context)
3803 {
3804  struct page *page;
3805  unsigned long end_pfn = start_pfn + size;
3806  unsigned long pfn;
3807  struct zone *z;
3808 
3809  if (highest_memmap_pfn < end_pfn - 1)
3810  highest_memmap_pfn = end_pfn - 1;
3811 
3812  z = &NODE_DATA(nid)->node_zones[zone];
3813  for (pfn = start_pfn; pfn < end_pfn; pfn++) {
3814  /*
3815  * There can be holes in boot-time mem_map[]s
3816  * handed to this function. They do not
3817  * exist on hotplugged memory.
3818  */
3819  if (context == MEMMAP_EARLY) {
3820  if (!early_pfn_valid(pfn))
3821  continue;
3822  if (!early_pfn_in_nid(pfn, nid))
3823  continue;
3824  }
3825  page = pfn_to_page(pfn);
3826  set_page_links(page, zone, nid, pfn);
3827  mminit_verify_page_links(page, zone, nid, pfn);
3828  init_page_count(page);
3829  reset_page_mapcount(page);
3830  SetPageReserved(page);
3831  /*
3832  * Mark the block movable so that blocks are reserved for
3833  * movable at startup. This will force kernel allocations
3834  * to reserve their blocks rather than leaking throughout
3835  * the address space during boot when many long-lived
3836  * kernel allocations are made. Later some blocks near
3837  * the start are marked MIGRATE_RESERVE by
3838  * setup_zone_migrate_reserve()
3839  *
3840  * bitmap is created for zone's valid pfn range. but memmap
3841  * can be created for invalid pages (for alignment)
3842  * check here not to call set_pageblock_migratetype() against
3843  * pfn out of zone.
3844  */
3845  if ((z->zone_start_pfn <= pfn)
3846  && (pfn < z->zone_start_pfn + z->spanned_pages)
3847  && !(pfn & (pageblock_nr_pages - 1)))
3849 
3850  INIT_LIST_HEAD(&page->lru);
3851 #ifdef WANT_PAGE_VIRTUAL
3852  /* The shift won't overflow because ZONE_NORMAL is below 4G. */
3853  if (!is_highmem_idx(zone))
3854  set_page_address(page, __va(pfn << PAGE_SHIFT));
3855 #endif
3856  }
3857 }
3858 
3859 static void __meminit zone_init_free_lists(struct zone *zone)
3860 {
3861  int order, t;
3862  for_each_migratetype_order(order, t) {
3863  INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
3864  zone->free_area[order].nr_free = 0;
3865  }
3866 }
3867 
3868 #ifndef __HAVE_ARCH_MEMMAP_INIT
3869 #define memmap_init(size, nid, zone, start_pfn) \
3870  memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
3871 #endif
3872 
3873 static int __meminit zone_batchsize(struct zone *zone)
3874 {
3875 #ifdef CONFIG_MMU
3876  int batch;
3877 
3878  /*
3879  * The per-cpu-pages pools are set to around 1000th of the
3880  * size of the zone. But no more than 1/2 of a meg.
3881  *
3882  * OK, so we don't know how big the cache is. So guess.
3883  */
3884  batch = zone->present_pages / 1024;
3885  if (batch * PAGE_SIZE > 512 * 1024)
3886  batch = (512 * 1024) / PAGE_SIZE;
3887  batch /= 4; /* We effectively *= 4 below */
3888  if (batch < 1)
3889  batch = 1;
3890 
3891  /*
3892  * Clamp the batch to a 2^n - 1 value. Having a power
3893  * of 2 value was found to be more likely to have
3894  * suboptimal cache aliasing properties in some cases.
3895  *
3896  * For example if 2 tasks are alternately allocating
3897  * batches of pages, one task can end up with a lot
3898  * of pages of one half of the possible page colors
3899  * and the other with pages of the other colors.
3900  */
3901  batch = rounddown_pow_of_two(batch + batch/2) - 1;
3902 
3903  return batch;
3904 
3905 #else
3906  /* The deferral and batching of frees should be suppressed under NOMMU
3907  * conditions.
3908  *
3909  * The problem is that NOMMU needs to be able to allocate large chunks
3910  * of contiguous memory as there's no hardware page translation to
3911  * assemble apparent contiguous memory from discontiguous pages.
3912  *
3913  * Queueing large contiguous runs of pages for batching, however,
3914  * causes the pages to actually be freed in smaller chunks. As there
3915  * can be a significant delay between the individual batches being
3916  * recycled, this leads to the once large chunks of space being
3917  * fragmented and becoming unavailable for high-order allocations.
3918  */
3919  return 0;
3920 #endif
3921 }
3922 
3923 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
3924 {
3925  struct per_cpu_pages *pcp;
3926  int migratetype;
3927 
3928  memset(p, 0, sizeof(*p));
3929 
3930  pcp = &p->pcp;
3931  pcp->count = 0;
3932  pcp->high = 6 * batch;
3933  pcp->batch = max(1UL, 1 * batch);
3934  for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
3935  INIT_LIST_HEAD(&pcp->lists[migratetype]);
3936 }
3937 
3938 /*
3939  * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
3940  * to the value high for the pageset p.
3941  */
3942 
3943 static void setup_pagelist_highmark(struct per_cpu_pageset *p,
3944  unsigned long high)
3945 {
3946  struct per_cpu_pages *pcp;
3947 
3948  pcp = &p->pcp;
3949  pcp->high = high;
3950  pcp->batch = max(1UL, high/4);
3951  if ((high/4) > (PAGE_SHIFT * 8))
3952  pcp->batch = PAGE_SHIFT * 8;
3953 }
3954 
3955 static void __meminit setup_zone_pageset(struct zone *zone)
3956 {
3957  int cpu;
3958 
3959  zone->pageset = alloc_percpu(struct per_cpu_pageset);
3960 
3961  for_each_possible_cpu(cpu) {
3962  struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
3963 
3964  setup_pageset(pcp, zone_batchsize(zone));
3965 
3967  setup_pagelist_highmark(pcp,
3968  (zone->present_pages /
3970  }
3971 }
3972 
3973 /*
3974  * Allocate per cpu pagesets and initialize them.
3975  * Before this call only boot pagesets were available.
3976  */
3978 {
3979  struct zone *zone;
3980 
3982  setup_zone_pageset(zone);
3983 }
3984 
3985 static noinline __init_refok
3986 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
3987 {
3988  int i;
3989  struct pglist_data *pgdat = zone->zone_pgdat;
3990  size_t alloc_size;
3991 
3992  /*
3993  * The per-page waitqueue mechanism uses hashed waitqueues
3994  * per zone.
3995  */
3997  wait_table_hash_nr_entries(zone_size_pages);
3998  zone->wait_table_bits =
3999  wait_table_bits(zone->wait_table_hash_nr_entries);
4000  alloc_size = zone->wait_table_hash_nr_entries
4001  * sizeof(wait_queue_head_t);
4002 
4003  if (!slab_is_available()) {
4004  zone->wait_table = (wait_queue_head_t *)
4005  alloc_bootmem_node_nopanic(pgdat, alloc_size);
4006  } else {
4007  /*
4008  * This case means that a zone whose size was 0 gets new memory
4009  * via memory hot-add.
4010  * But it may be the case that a new node was hot-added. In
4011  * this case vmalloc() will not be able to use this new node's
4012  * memory - this wait_table must be initialized to use this new
4013  * node itself as well.
4014  * To use this new node's memory, further consideration will be
4015  * necessary.
4016  */
4017  zone->wait_table = vmalloc(alloc_size);
4018  }
4019  if (!zone->wait_table)
4020  return -ENOMEM;
4021 
4022  for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
4023  init_waitqueue_head(zone->wait_table + i);
4024 
4025  return 0;
4026 }
4027 
4028 static __meminit void zone_pcp_init(struct zone *zone)
4029 {
4030  /*
4031  * per cpu subsystem is not up at this point. The following code
4032  * relies on the ability of the linker to provide the
4033  * offset of a (static) per cpu variable into the per cpu area.
4034  */
4035  zone->pageset = &boot_pageset;
4036 
4037  if (zone->present_pages)
4038  printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
4039  zone->name, zone->present_pages,
4040  zone_batchsize(zone));
4041 }
4042 
4043 int __meminit init_currently_empty_zone(struct zone *zone,
4044  unsigned long zone_start_pfn,
4045  unsigned long size,
4046  enum memmap_context context)
4047 {
4048  struct pglist_data *pgdat = zone->zone_pgdat;
4049  int ret;
4050  ret = zone_wait_table_init(zone, size);
4051  if (ret)
4052  return ret;
4053  pgdat->nr_zones = zone_idx(zone) + 1;
4054 
4055  zone->zone_start_pfn = zone_start_pfn;
4056 
4057  mminit_dprintk(MMINIT_TRACE, "memmap_init",
4058  "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4059  pgdat->node_id,
4060  (unsigned long)zone_idx(zone),
4061  zone_start_pfn, (zone_start_pfn + size));
4062 
4063  zone_init_free_lists(zone);
4064 
4065  return 0;
4066 }
4067 
4068 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4069 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4070 /*
4071  * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4072  * Architectures may implement their own version but if add_active_range()
4073  * was used and there are no special requirements, this is a convenient
4074  * alternative
4075  */
4076 int __meminit __early_pfn_to_nid(unsigned long pfn)
4077 {
4078  unsigned long start_pfn, end_pfn;
4079  int i, nid;
4080 
4081  for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
4082  if (start_pfn <= pfn && pfn < end_pfn)
4083  return nid;
4084  /* This is a memory hole */
4085  return -1;
4086 }
4087 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
4088 
4089 int __meminit early_pfn_to_nid(unsigned long pfn)
4090 {
4091  int nid;
4092 
4093  nid = __early_pfn_to_nid(pfn);
4094  if (nid >= 0)
4095  return nid;
4096  /* just returns 0 */
4097  return 0;
4098 }
4099 
4100 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
4101 bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
4102 {
4103  int nid;
4104 
4105  nid = __early_pfn_to_nid(pfn);
4106  if (nid >= 0 && nid != node)
4107  return false;
4108  return true;
4109 }
4110 #endif
4111 
4121 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
4122 {
4123  unsigned long start_pfn, end_pfn;
4124  int i, this_nid;
4125 
4126  for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
4127  start_pfn = min(start_pfn, max_low_pfn);
4128  end_pfn = min(end_pfn, max_low_pfn);
4129 
4130  if (start_pfn < end_pfn)
4131  free_bootmem_node(NODE_DATA(this_nid),
4132  PFN_PHYS(start_pfn),
4133  (end_pfn - start_pfn) << PAGE_SHIFT);
4134  }
4135 }
4136 
4145 void __init sparse_memory_present_with_active_regions(int nid)
4146 {
4147  unsigned long start_pfn, end_pfn;
4148  int i, this_nid;
4149 
4150  for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
4151  memory_present(this_nid, start_pfn, end_pfn);
4152 }
4153 
4165 void __meminit get_pfn_range_for_nid(unsigned int nid,
4166  unsigned long *start_pfn, unsigned long *end_pfn)
4167 {
4168  unsigned long this_start_pfn, this_end_pfn;
4169  int i;
4170 
4171  *start_pfn = -1UL;
4172  *end_pfn = 0;
4173 
4174  for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
4175  *start_pfn = min(*start_pfn, this_start_pfn);
4176  *end_pfn = max(*end_pfn, this_end_pfn);
4177  }
4178 
4179  if (*start_pfn == -1UL)
4180  *start_pfn = 0;
4181 }
4182 
4183 /*
4184  * This finds a zone that can be used for ZONE_MOVABLE pages. The
4185  * assumption is made that zones within a node are ordered in monotonic
4186  * increasing memory addresses so that the "highest" populated zone is used
4187  */
4188 static void __init find_usable_zone_for_movable(void)
4189 {
4190  int zone_index;
4191  for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
4192  if (zone_index == ZONE_MOVABLE)
4193  continue;
4194 
4195  if (arch_zone_highest_possible_pfn[zone_index] >
4196  arch_zone_lowest_possible_pfn[zone_index])
4197  break;
4198  }
4199 
4200  VM_BUG_ON(zone_index == -1);
4201  movable_zone = zone_index;
4202 }
4203 
4204 /*
4205  * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4206  * because it is sized independent of architecture. Unlike the other zones,
4207  * the starting point for ZONE_MOVABLE is not fixed. It may be different
4208  * in each node depending on the size of each node and how evenly kernelcore
4209  * is distributed. This helper function adjusts the zone ranges
4210  * provided by the architecture for a given node by using the end of the
4211  * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4212  * zones within a node are in order of monotonic increases memory addresses
4213  */
4214 static void __meminit adjust_zone_range_for_zone_movable(int nid,
4215  unsigned long zone_type,
4216  unsigned long node_start_pfn,
4217  unsigned long node_end_pfn,
4218  unsigned long *zone_start_pfn,
4219  unsigned long *zone_end_pfn)
4220 {
4221  /* Only adjust if ZONE_MOVABLE is on this node */
4222  if (zone_movable_pfn[nid]) {
4223  /* Size ZONE_MOVABLE */
4224  if (zone_type == ZONE_MOVABLE) {
4225  *zone_start_pfn = zone_movable_pfn[nid];
4226  *zone_end_pfn = min(node_end_pfn,
4227  arch_zone_highest_possible_pfn[movable_zone]);
4228 
4229  /* Adjust for ZONE_MOVABLE starting within this range */
4230  } else if (*zone_start_pfn < zone_movable_pfn[nid] &&
4231  *zone_end_pfn > zone_movable_pfn[nid]) {
4232  *zone_end_pfn = zone_movable_pfn[nid];
4233 
4234  /* Check if this whole range is within ZONE_MOVABLE */
4235  } else if (*zone_start_pfn >= zone_movable_pfn[nid])
4236  *zone_start_pfn = *zone_end_pfn;
4237  }
4238 }
4239 
4240 /*
4241  * Return the number of pages a zone spans in a node, including holes
4242  * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4243  */
4244 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
4245  unsigned long zone_type,
4246  unsigned long *ignored)
4247 {
4248  unsigned long node_start_pfn, node_end_pfn;
4249  unsigned long zone_start_pfn, zone_end_pfn;
4250 
4251  /* Get the start and end of the node and zone */
4252  get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
4253  zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
4254  zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
4255  adjust_zone_range_for_zone_movable(nid, zone_type,
4256  node_start_pfn, node_end_pfn,
4257  &zone_start_pfn, &zone_end_pfn);
4258 
4259  /* Check that this node has pages within the zone's required range */
4260  if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn)
4261  return 0;
4262 
4263  /* Move the zone boundaries inside the node if necessary */
4264  zone_end_pfn = min(zone_end_pfn, node_end_pfn);
4265  zone_start_pfn = max(zone_start_pfn, node_start_pfn);
4266 
4267  /* Return the spanned pages */
4268  return zone_end_pfn - zone_start_pfn;
4269 }
4270 
4271 /*
4272  * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4273  * then all holes in the requested range will be accounted for.
4274  */
4275 unsigned long __meminit __absent_pages_in_range(int nid,
4276  unsigned long range_start_pfn,
4277  unsigned long range_end_pfn)
4278 {
4279  unsigned long nr_absent = range_end_pfn - range_start_pfn;
4280  unsigned long start_pfn, end_pfn;
4281  int i;
4282 
4283  for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
4284  start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
4285  end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
4286  nr_absent -= end_pfn - start_pfn;
4287  }
4288  return nr_absent;
4289 }
4290 
4298 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
4299  unsigned long end_pfn)
4300 {
4301  return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
4302 }
4303 
4304 /* Return the number of page frames in holes in a zone on a node */
4305 static unsigned long __meminit zone_absent_pages_in_node(int nid,
4306  unsigned long zone_type,
4307  unsigned long *ignored)
4308 {
4309  unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
4310  unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
4311  unsigned long node_start_pfn, node_end_pfn;
4312  unsigned long zone_start_pfn, zone_end_pfn;
4313 
4314  get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
4315  zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
4316  zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
4317 
4318  adjust_zone_range_for_zone_movable(nid, zone_type,
4319  node_start_pfn, node_end_pfn,
4320  &zone_start_pfn, &zone_end_pfn);
4321  return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
4322 }
4323 
4324 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4325 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
4326  unsigned long zone_type,
4327  unsigned long *zones_size)
4328 {
4329  return zones_size[zone_type];
4330 }
4331 
4332 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
4333  unsigned long zone_type,
4334  unsigned long *zholes_size)
4335 {
4336  if (!zholes_size)
4337  return 0;
4338 
4339  return zholes_size[zone_type];
4340 }
4341 
4342 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4343 
4344 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
4345  unsigned long *zones_size, unsigned long *zholes_size)
4346 {
4347  unsigned long realtotalpages, totalpages = 0;
4348  enum zone_type i;
4349 
4350  for (i = 0; i < MAX_NR_ZONES; i++)
4351  totalpages += zone_spanned_pages_in_node(pgdat->node_id, i,
4352  zones_size);
4353  pgdat->node_spanned_pages = totalpages;
4354 
4355  realtotalpages = totalpages;
4356  for (i = 0; i < MAX_NR_ZONES; i++)
4357  realtotalpages -=
4358  zone_absent_pages_in_node(pgdat->node_id, i,
4359  zholes_size);
4360  pgdat->node_present_pages = realtotalpages;
4361  printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
4362  realtotalpages);
4363 }
4364 
4365 #ifndef CONFIG_SPARSEMEM
4366 /*
4367  * Calculate the size of the zone->blockflags rounded to an unsigned long
4368  * Start by making sure zonesize is a multiple of pageblock_order by rounding
4369  * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4370  * round what is now in bits to nearest long in bits, then return it in
4371  * bytes.
4372  */
4373 static unsigned long __init usemap_size(unsigned long zonesize)
4374 {
4375  unsigned long usemapsize;
4376 
4377  usemapsize = roundup(zonesize, pageblock_nr_pages);
4378  usemapsize = usemapsize >> pageblock_order;
4379  usemapsize *= NR_PAGEBLOCK_BITS;
4380  usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
4381 
4382  return usemapsize / 8;
4383 }
4384 
4385 static void __init setup_usemap(struct pglist_data *pgdat,
4386  struct zone *zone, unsigned long zonesize)
4387 {
4388  unsigned long usemapsize = usemap_size(zonesize);
4389  zone->pageblock_flags = NULL;
4390  if (usemapsize)
4392  usemapsize);
4393 }
4394 #else
4395 static inline void setup_usemap(struct pglist_data *pgdat,
4396  struct zone *zone, unsigned long zonesize) {}
4397 #endif /* CONFIG_SPARSEMEM */
4398 
4399 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4400 
4401 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4402 void __init set_pageblock_order(void)
4403 {
4404  unsigned int order;
4405 
4406  /* Check that pageblock_nr_pages has not already been setup */
4407  if (pageblock_order)
4408  return;
4409 
4410  if (HPAGE_SHIFT > PAGE_SHIFT)
4411  order = HUGETLB_PAGE_ORDER;
4412  else
4413  order = MAX_ORDER - 1;
4414 
4415  /*
4416  * Assume the largest contiguous order of interest is a huge page.
4417  * This value may be variable depending on boot parameters on IA64 and
4418  * powerpc.
4419  */
4420  pageblock_order = order;
4421 }
4422 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4423 
4424 /*
4425  * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4426  * is unused as pageblock_order is set at compile-time. See
4427  * include/linux/pageblock-flags.h for the values of pageblock_order based on
4428  * the kernel config
4429  */
4431 {
4432 }
4433 
4434 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4435 
4436 /*
4437  * Set up the zone data structures:
4438  * - mark all pages reserved
4439  * - mark all memory queues empty
4440  * - clear the memory bitmaps
4441  *
4442  * NOTE: pgdat should get zeroed by caller.
4443  */
4444 static void __paginginit free_area_init_core(struct pglist_data *pgdat,
4445  unsigned long *zones_size, unsigned long *zholes_size)
4446 {
4447  enum zone_type j;
4448  int nid = pgdat->node_id;
4449  unsigned long zone_start_pfn = pgdat->node_start_pfn;
4450  int ret;
4451 
4452  pgdat_resize_init(pgdat);
4455  pgdat_page_cgroup_init(pgdat);
4456 
4457  for (j = 0; j < MAX_NR_ZONES; j++) {
4458  struct zone *zone = pgdat->node_zones + j;
4459  unsigned long size, realsize, memmap_pages;
4460 
4461  size = zone_spanned_pages_in_node(nid, j, zones_size);
4462  realsize = size - zone_absent_pages_in_node(nid, j,
4463  zholes_size);
4464 
4465  /*
4466  * Adjust realsize so that it accounts for how much memory
4467  * is used by this zone for memmap. This affects the watermark
4468  * and per-cpu initialisations
4469  */
4470  memmap_pages =
4471  PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
4472  if (realsize >= memmap_pages) {
4473  realsize -= memmap_pages;
4474  if (memmap_pages)
4476  " %s zone: %lu pages used for memmap\n",
4477  zone_names[j], memmap_pages);
4478  } else
4480  " %s zone: %lu pages exceeds realsize %lu\n",
4481  zone_names[j], memmap_pages, realsize);
4482 
4483  /* Account for reserved pages */
4484  if (j == 0 && realsize > dma_reserve) {
4485  realsize -= dma_reserve;
4486  printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
4487  zone_names[0], dma_reserve);
4488  }
4489 
4490  if (!is_highmem_idx(j))
4491  nr_kernel_pages += realsize;
4492  nr_all_pages += realsize;
4493 
4494  zone->spanned_pages = size;
4495  zone->present_pages = realsize;
4496 #ifdef CONFIG_NUMA
4497  zone->node = nid;
4498  zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
4499  / 100;
4500  zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
4501 #endif
4502  zone->name = zone_names[j];
4503  spin_lock_init(&zone->lock);
4504  spin_lock_init(&zone->lru_lock);
4505  zone_seqlock_init(zone);
4506  zone->zone_pgdat = pgdat;
4507 
4508  zone_pcp_init(zone);
4509  lruvec_init(&zone->lruvec);
4510  if (!size)
4511  continue;
4512 
4514  setup_usemap(pgdat, zone, size);
4515  ret = init_currently_empty_zone(zone, zone_start_pfn,
4516  size, MEMMAP_EARLY);
4517  BUG_ON(ret);
4518  memmap_init(size, nid, j, zone_start_pfn);
4519  zone_start_pfn += size;
4520  }
4521 }
4522 
4523 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
4524 {
4525  /* Skip empty nodes */
4526  if (!pgdat->node_spanned_pages)
4527  return;
4528 
4529 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4530  /* ia64 gets its own node_mem_map, before this, without bootmem */
4531  if (!pgdat->node_mem_map) {
4532  unsigned long size, start, end;
4533  struct page *map;
4534 
4535  /*
4536  * The zone's endpoints aren't required to be MAX_ORDER
4537  * aligned but the node_mem_map endpoints must be in order
4538  * for the buddy allocator to function correctly.
4539  */
4540  start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
4541  end = pgdat->node_start_pfn + pgdat->node_spanned_pages;
4542  end = ALIGN(end, MAX_ORDER_NR_PAGES);
4543  size = (end - start) * sizeof(struct page);
4544  map = alloc_remap(pgdat->node_id, size);
4545  if (!map)
4546  map = alloc_bootmem_node_nopanic(pgdat, size);
4547  pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
4548  }
4549 #ifndef CONFIG_NEED_MULTIPLE_NODES
4550  /*
4551  * With no DISCONTIG, the global mem_map is just set as node 0's
4552  */
4553  if (pgdat == NODE_DATA(0)) {
4554  mem_map = NODE_DATA(0)->node_mem_map;
4555 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4556  if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
4557  mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
4558 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4559  }
4560 #endif
4561 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
4562 }
4563 
4564 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
4565  unsigned long node_start_pfn, unsigned long *zholes_size)
4566 {
4567  pg_data_t *pgdat = NODE_DATA(nid);
4568 
4569  /* pg_data_t should be reset to zero when it's allocated */
4570  WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
4571 
4572  pgdat->node_id = nid;
4573  pgdat->node_start_pfn = node_start_pfn;
4574  init_zone_allows_reclaim(nid);
4575  calculate_node_totalpages(pgdat, zones_size, zholes_size);
4576 
4577  alloc_node_mem_map(pgdat);
4578 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4579  printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
4580  nid, (unsigned long)pgdat,
4581  (unsigned long)pgdat->node_mem_map);
4582 #endif
4583 
4584  free_area_init_core(pgdat, zones_size, zholes_size);
4585 }
4586 
4587 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4588 
4589 #if MAX_NUMNODES > 1
4590 /*
4591  * Figure out the number of possible node ids.
4592  */
4593 static void __init setup_nr_node_ids(void)
4594 {
4595  unsigned int node;
4596  unsigned int highest = 0;
4597 
4599  highest = node;
4600  nr_node_ids = highest + 1;
4601 }
4602 #else
4603 static inline void setup_nr_node_ids(void)
4604 {
4605 }
4606 #endif
4607 
4627 unsigned long __init node_map_pfn_alignment(void)
4628 {
4629  unsigned long accl_mask = 0, last_end = 0;
4630  unsigned long start, end, mask;
4631  int last_nid = -1;
4632  int i, nid;
4633 
4634  for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
4635  if (!start || last_nid < 0 || last_nid == nid) {
4636  last_nid = nid;
4637  last_end = end;
4638  continue;
4639  }
4640 
4641  /*
4642  * Start with a mask granular enough to pin-point to the
4643  * start pfn and tick off bits one-by-one until it becomes
4644  * too coarse to separate the current node from the last.
4645  */
4646  mask = ~((1 << __ffs(start)) - 1);
4647  while (mask && last_end <= (start & (mask << 1)))
4648  mask <<= 1;
4649 
4650  /* accumulate all internode masks */
4651  accl_mask |= mask;
4652  }
4653 
4654  /* convert mask to number of pages */
4655  return ~accl_mask + 1;
4656 }
4657 
4658 /* Find the lowest pfn for a node */
4659 static unsigned long __init find_min_pfn_for_node(int nid)
4660 {
4661  unsigned long min_pfn = ULONG_MAX;
4662  unsigned long start_pfn;
4663  int i;
4664 
4665  for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
4666  min_pfn = min(min_pfn, start_pfn);
4667 
4668  if (min_pfn == ULONG_MAX) {
4670  "Could not find start_pfn for node %d\n", nid);
4671  return 0;
4672  }
4673 
4674  return min_pfn;
4675 }
4676 
4683 unsigned long __init find_min_pfn_with_active_regions(void)
4684 {
4685  return find_min_pfn_for_node(MAX_NUMNODES);
4686 }
4687 
4688 /*
4689  * early_calculate_totalpages()
4690  * Sum pages in active regions for movable zone.
4691  * Populate N_HIGH_MEMORY for calculating usable_nodes.
4692  */
4693 static unsigned long __init early_calculate_totalpages(void)
4694 {
4695  unsigned long totalpages = 0;
4696  unsigned long start_pfn, end_pfn;
4697  int i, nid;
4698 
4699  for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
4700  unsigned long pages = end_pfn - start_pfn;
4701 
4702  totalpages += pages;
4703  if (pages)
4704  node_set_state(nid, N_HIGH_MEMORY);
4705  }
4706  return totalpages;
4707 }
4708 
4709 /*
4710  * Find the PFN the Movable zone begins in each node. Kernel memory
4711  * is spread evenly between nodes as long as the nodes have enough
4712  * memory. When they don't, some nodes will have more kernelcore than
4713  * others
4714  */
4715 static void __init find_zone_movable_pfns_for_nodes(void)
4716 {
4717  int i, nid;
4718  unsigned long usable_startpfn;
4719  unsigned long kernelcore_node, kernelcore_remaining;
4720  /* save the state before borrow the nodemask */
4721  nodemask_t saved_node_state = node_states[N_HIGH_MEMORY];
4722  unsigned long totalpages = early_calculate_totalpages();
4723  int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
4724 
4725  /*
4726  * If movablecore was specified, calculate what size of
4727  * kernelcore that corresponds so that memory usable for
4728  * any allocation type is evenly spread. If both kernelcore
4729  * and movablecore are specified, then the value of kernelcore
4730  * will be used for required_kernelcore if it's greater than
4731  * what movablecore would have allowed.
4732  */
4733  if (required_movablecore) {
4734  unsigned long corepages;
4735 
4736  /*
4737  * Round-up so that ZONE_MOVABLE is at least as large as what
4738  * was requested by the user
4739  */
4740  required_movablecore =
4741  roundup(required_movablecore, MAX_ORDER_NR_PAGES);
4742  corepages = totalpages - required_movablecore;
4743 
4744  required_kernelcore = max(required_kernelcore, corepages);
4745  }
4746 
4747  /* If kernelcore was not specified, there is no ZONE_MOVABLE */
4748  if (!required_kernelcore)
4749  goto out;
4750 
4751  /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
4752  find_usable_zone_for_movable();
4753  usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
4754 
4755 restart:
4756  /* Spread kernelcore memory as evenly as possible throughout nodes */
4757  kernelcore_node = required_kernelcore / usable_nodes;
4759  unsigned long start_pfn, end_pfn;
4760 
4761  /*
4762  * Recalculate kernelcore_node if the division per node
4763  * now exceeds what is necessary to satisfy the requested
4764  * amount of memory for the kernel
4765  */
4766  if (required_kernelcore < kernelcore_node)
4767  kernelcore_node = required_kernelcore / usable_nodes;
4768 
4769  /*
4770  * As the map is walked, we track how much memory is usable
4771  * by the kernel using kernelcore_remaining. When it is
4772  * 0, the rest of the node is usable by ZONE_MOVABLE
4773  */
4774  kernelcore_remaining = kernelcore_node;
4775 
4776  /* Go through each range of PFNs within this node */
4777  for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
4778  unsigned long size_pages;
4779 
4780  start_pfn = max(start_pfn, zone_movable_pfn[nid]);
4781  if (start_pfn >= end_pfn)
4782  continue;
4783 
4784  /* Account for what is only usable for kernelcore */
4785  if (start_pfn < usable_startpfn) {
4786  unsigned long kernel_pages;
4787  kernel_pages = min(end_pfn, usable_startpfn)
4788  - start_pfn;
4789 
4790  kernelcore_remaining -= min(kernel_pages,
4791  kernelcore_remaining);
4792  required_kernelcore -= min(kernel_pages,
4793  required_kernelcore);
4794 
4795  /* Continue if range is now fully accounted */
4796  if (end_pfn <= usable_startpfn) {
4797 
4798  /*
4799  * Push zone_movable_pfn to the end so
4800  * that if we have to rebalance
4801  * kernelcore across nodes, we will
4802  * not double account here
4803  */
4804  zone_movable_pfn[nid] = end_pfn;
4805  continue;
4806  }
4807  start_pfn = usable_startpfn;
4808  }
4809 
4810  /*
4811  * The usable PFN range for ZONE_MOVABLE is from
4812  * start_pfn->end_pfn. Calculate size_pages as the
4813  * number of pages used as kernelcore
4814  */
4815  size_pages = end_pfn - start_pfn;
4816  if (size_pages > kernelcore_remaining)
4817  size_pages = kernelcore_remaining;
4818  zone_movable_pfn[nid] = start_pfn + size_pages;
4819 
4820  /*
4821  * Some kernelcore has been met, update counts and
4822  * break if the kernelcore for this node has been
4823  * satisified
4824  */
4825  required_kernelcore -= min(required_kernelcore,
4826  size_pages);
4827  kernelcore_remaining -= size_pages;
4828  if (!kernelcore_remaining)
4829  break;
4830  }
4831  }
4832 
4833  /*
4834  * If there is still required_kernelcore, we do another pass with one
4835  * less node in the count. This will push zone_movable_pfn[nid] further
4836  * along on the nodes that still have memory until kernelcore is
4837  * satisified
4838  */
4839  usable_nodes--;
4840  if (usable_nodes && required_kernelcore > usable_nodes)
4841  goto restart;
4842 
4843  /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
4844  for (nid = 0; nid < MAX_NUMNODES; nid++)
4845  zone_movable_pfn[nid] =
4846  roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
4847 
4848 out:
4849  /* restore the node_state */
4850  node_states[N_HIGH_MEMORY] = saved_node_state;
4851 }
4852 
4853 /* Any regular memory on that node ? */
4854 static void __init check_for_regular_memory(pg_data_t *pgdat)
4855 {
4856 #ifdef CONFIG_HIGHMEM
4857  enum zone_type zone_type;
4858 
4859  for (zone_type = 0; zone_type <= ZONE_NORMAL; zone_type++) {
4860  struct zone *zone = &pgdat->node_zones[zone_type];
4861  if (zone->present_pages) {
4862  node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY);
4863  break;
4864  }
4865  }
4866 #endif
4867 }
4868 
4882 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
4883 {
4884  unsigned long start_pfn, end_pfn;
4885  int i, nid;
4886 
4887  /* Record where the zone boundaries are */
4888  memset(arch_zone_lowest_possible_pfn, 0,
4889  sizeof(arch_zone_lowest_possible_pfn));
4890  memset(arch_zone_highest_possible_pfn, 0,
4891  sizeof(arch_zone_highest_possible_pfn));
4892  arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
4893  arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
4894  for (i = 1; i < MAX_NR_ZONES; i++) {
4895  if (i == ZONE_MOVABLE)
4896  continue;
4897  arch_zone_lowest_possible_pfn[i] =
4898  arch_zone_highest_possible_pfn[i-1];
4899  arch_zone_highest_possible_pfn[i] =
4900  max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
4901  }
4902  arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
4903  arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
4904 
4905  /* Find the PFNs that ZONE_MOVABLE begins at in each node */
4906  memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
4907  find_zone_movable_pfns_for_nodes();
4908 
4909  /* Print out the zone ranges */
4910  printk("Zone ranges:\n");
4911  for (i = 0; i < MAX_NR_ZONES; i++) {
4912  if (i == ZONE_MOVABLE)
4913  continue;
4914  printk(KERN_CONT " %-8s ", zone_names[i]);
4915  if (arch_zone_lowest_possible_pfn[i] ==
4916  arch_zone_highest_possible_pfn[i])
4917  printk(KERN_CONT "empty\n");
4918  else
4919  printk(KERN_CONT "[mem %0#10lx-%0#10lx]\n",
4920  arch_zone_lowest_possible_pfn[i] << PAGE_SHIFT,
4921  (arch_zone_highest_possible_pfn[i]
4922  << PAGE_SHIFT) - 1);
4923  }
4924 
4925  /* Print out the PFNs ZONE_MOVABLE begins at in each node */
4926  printk("Movable zone start for each node\n");
4927  for (i = 0; i < MAX_NUMNODES; i++) {
4928  if (zone_movable_pfn[i])
4929  printk(" Node %d: %#010lx\n", i,
4930  zone_movable_pfn[i] << PAGE_SHIFT);
4931  }
4932 
4933  /* Print out the early node map */
4934  printk("Early memory node ranges\n");
4935  for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
4936  printk(" node %3d: [mem %#010lx-%#010lx]\n", nid,
4937  start_pfn << PAGE_SHIFT, (end_pfn << PAGE_SHIFT) - 1);
4938 
4939  /* Initialise every node */
4940  mminit_verify_pageflags_layout();
4941  setup_nr_node_ids();
4942  for_each_online_node(nid) {
4943  pg_data_t *pgdat = NODE_DATA(nid);
4945  find_min_pfn_for_node(nid), NULL);
4946 
4947  /* Any memory on that node */
4948  if (pgdat->node_present_pages)
4949  node_set_state(nid, N_HIGH_MEMORY);
4950  check_for_regular_memory(pgdat);
4951  }
4952 }
4953 
4954 static int __init cmdline_parse_core(char *p, unsigned long *core)
4955 {
4956  unsigned long long coremem;
4957  if (!p)
4958  return -EINVAL;
4959 
4960  coremem = memparse(p, &p);
4961  *core = coremem >> PAGE_SHIFT;
4962 
4963  /* Paranoid check that UL is enough for the coremem value */
4964  WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
4965 
4966  return 0;
4967 }
4968 
4969 /*
4970  * kernelcore=size sets the amount of memory for use for allocations that
4971  * cannot be reclaimed or migrated.
4972  */
4973 static int __init cmdline_parse_kernelcore(char *p)
4974 {
4975  return cmdline_parse_core(p, &required_kernelcore);
4976 }
4977 
4978 /*
4979  * movablecore=size sets the amount of memory for use for allocations that
4980  * can be reclaimed or migrated.
4981  */
4982 static int __init cmdline_parse_movablecore(char *p)
4983 {
4984  return cmdline_parse_core(p, &required_movablecore);
4985 }
4986 
4987 early_param("kernelcore", cmdline_parse_kernelcore);
4988 early_param("movablecore", cmdline_parse_movablecore);
4989 
4990 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4991 
5003 void __init set_dma_reserve(unsigned long new_dma_reserve)
5004 {
5005  dma_reserve = new_dma_reserve;
5006 }
5007 
5008 void __init free_area_init(unsigned long *zones_size)
5009 {
5010  free_area_init_node(0, zones_size,
5011  __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
5012 }
5013 
5014 static int page_alloc_cpu_notify(struct notifier_block *self,
5015  unsigned long action, void *hcpu)
5016 {
5017  int cpu = (unsigned long)hcpu;
5018 
5019  if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
5020  lru_add_drain_cpu(cpu);
5021  drain_pages(cpu);
5022 
5023  /*
5024  * Spill the event counters of the dead processor
5025  * into the current processors event counters.
5026  * This artificially elevates the count of the current
5027  * processor.
5028  */
5029  vm_events_fold_cpu(cpu);
5030 
5031  /*
5032  * Zero the differential counters of the dead processor
5033  * so that the vm statistics are consistent.
5034  *
5035  * This is only okay since the processor is dead and cannot
5036  * race with what we are doing.
5037  */
5038  refresh_cpu_vm_stats(cpu);
5039  }
5040  return NOTIFY_OK;
5041 }
5042 
5044 {
5045  hotcpu_notifier(page_alloc_cpu_notify, 0);
5046 }
5047 
5048 /*
5049  * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
5050  * or min_free_kbytes changes.
5051  */
5052 static void calculate_totalreserve_pages(void)
5053 {
5054  struct pglist_data *pgdat;
5055  unsigned long reserve_pages = 0;
5056  enum zone_type i, j;
5057 
5058  for_each_online_pgdat(pgdat) {
5059  for (i = 0; i < MAX_NR_ZONES; i++) {
5060  struct zone *zone = pgdat->node_zones + i;
5061  unsigned long max = 0;
5062 
5063  /* Find valid and maximum lowmem_reserve in the zone */
5064  for (j = i; j < MAX_NR_ZONES; j++) {
5065  if (zone->lowmem_reserve[j] > max)
5066  max = zone->lowmem_reserve[j];
5067  }
5068 
5069  /* we treat the high watermark as reserved pages. */
5070  max += high_wmark_pages(zone);
5071 
5072  if (max > zone->present_pages)
5073  max = zone->present_pages;
5074  reserve_pages += max;
5075  /*
5076  * Lowmem reserves are not available to
5077  * GFP_HIGHUSER page cache allocations and
5078  * kswapd tries to balance zones to their high
5079  * watermark. As a result, neither should be
5080  * regarded as dirtyable memory, to prevent a
5081  * situation where reclaim has to clean pages
5082  * in order to balance the zones.
5083  */
5084  zone->dirty_balance_reserve = max;
5085  }
5086  }
5087  dirty_balance_reserve = reserve_pages;
5088  totalreserve_pages = reserve_pages;
5089 }
5090 
5091 /*
5092  * setup_per_zone_lowmem_reserve - called whenever
5093  * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
5094  * has a correct pages reserved value, so an adequate number of
5095  * pages are left in the zone after a successful __alloc_pages().
5096  */
5097 static void setup_per_zone_lowmem_reserve(void)
5098 {
5099  struct pglist_data *pgdat;
5100  enum zone_type j, idx;
5101 
5102  for_each_online_pgdat(pgdat) {
5103  for (j = 0; j < MAX_NR_ZONES; j++) {
5104  struct zone *zone = pgdat->node_zones + j;
5105  unsigned long present_pages = zone->present_pages;
5106 
5107  zone->lowmem_reserve[j] = 0;
5108 
5109  idx = j;
5110  while (idx) {
5111  struct zone *lower_zone;
5112 
5113  idx--;
5114 
5115  if (sysctl_lowmem_reserve_ratio[idx] < 1)
5116  sysctl_lowmem_reserve_ratio[idx] = 1;
5117 
5118  lower_zone = pgdat->node_zones + idx;
5119  lower_zone->lowmem_reserve[j] = present_pages /
5120  sysctl_lowmem_reserve_ratio[idx];
5121  present_pages += lower_zone->present_pages;
5122  }
5123  }
5124  }
5125 
5126  /* update totalreserve_pages */
5127  calculate_totalreserve_pages();
5128 }
5129 
5130 static void __setup_per_zone_wmarks(void)
5131 {
5132  unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
5133  unsigned long lowmem_pages = 0;
5134  struct zone *zone;
5135  unsigned long flags;
5136 
5137  /* Calculate total number of !ZONE_HIGHMEM pages */
5138  for_each_zone(zone) {
5139  if (!is_highmem(zone))
5140  lowmem_pages += zone->present_pages;
5141  }
5142 
5143  for_each_zone(zone) {
5144  u64 tmp;
5145 
5146  spin_lock_irqsave(&zone->lock, flags);
5147  tmp = (u64)pages_min * zone->present_pages;
5148  do_div(tmp, lowmem_pages);
5149  if (is_highmem(zone)) {
5150  /*
5151  * __GFP_HIGH and PF_MEMALLOC allocations usually don't
5152  * need highmem pages, so cap pages_min to a small
5153  * value here.
5154  *
5155  * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
5156  * deltas controls asynch page reclaim, and so should
5157  * not be capped for highmem.
5158  */
5159  int min_pages;
5160 
5161  min_pages = zone->present_pages / 1024;
5162  if (min_pages < SWAP_CLUSTER_MAX)
5163  min_pages = SWAP_CLUSTER_MAX;
5164  if (min_pages > 128)
5165  min_pages = 128;
5166  zone->watermark[WMARK_MIN] = min_pages;
5167  } else {
5168  /*
5169  * If it's a lowmem zone, reserve a number of pages
5170  * proportionate to the zone's size.
5171  */
5172  zone->watermark[WMARK_MIN] = tmp;
5173  }
5174 
5175  zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2);
5176  zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
5177 
5178  zone->watermark[WMARK_MIN] += cma_wmark_pages(zone);
5179  zone->watermark[WMARK_LOW] += cma_wmark_pages(zone);
5180  zone->watermark[WMARK_HIGH] += cma_wmark_pages(zone);
5181 
5182  setup_zone_migrate_reserve(zone);
5183  spin_unlock_irqrestore(&zone->lock, flags);
5184  }
5185 
5186  /* update totalreserve_pages */
5187  calculate_totalreserve_pages();
5188 }
5189 
5198 {
5200  __setup_per_zone_wmarks();
5202 }
5203 
5204 /*
5205  * The inactive anon list should be small enough that the VM never has to
5206  * do too much work, but large enough that each inactive page has a chance
5207  * to be referenced again before it is swapped out.
5208  *
5209  * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
5210  * INACTIVE_ANON pages on this zone's LRU, maintained by the
5211  * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
5212  * the anonymous pages are kept on the inactive list.
5213  *
5214  * total target max
5215  * memory ratio inactive anon
5216  * -------------------------------------
5217  * 10MB 1 5MB
5218  * 100MB 1 50MB
5219  * 1GB 3 250MB
5220  * 10GB 10 0.9GB
5221  * 100GB 31 3GB
5222  * 1TB 101 10GB
5223  * 10TB 320 32GB
5224  */
5225 static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
5226 {
5227  unsigned int gb, ratio;
5228 
5229  /* Zone size in gigabytes */
5230  gb = zone->present_pages >> (30 - PAGE_SHIFT);
5231  if (gb)
5232  ratio = int_sqrt(10 * gb);
5233  else
5234  ratio = 1;
5235 
5236  zone->inactive_ratio = ratio;
5237 }
5238 
5239 static void __meminit setup_per_zone_inactive_ratio(void)
5240 {
5241  struct zone *zone;
5242 
5243  for_each_zone(zone)
5244  calculate_zone_inactive_ratio(zone);
5245 }
5246 
5247 /*
5248  * Initialise min_free_kbytes.
5249  *
5250  * For small machines we want it small (128k min). For large machines
5251  * we want it large (64MB max). But it is not linear, because network
5252  * bandwidth does not increase linearly with machine size. We use
5253  *
5254  * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
5255  * min_free_kbytes = sqrt(lowmem_kbytes * 16)
5256  *
5257  * which yields
5258  *
5259  * 16MB: 512k
5260  * 32MB: 724k
5261  * 64MB: 1024k
5262  * 128MB: 1448k
5263  * 256MB: 2048k
5264  * 512MB: 2896k
5265  * 1024MB: 4096k
5266  * 2048MB: 5792k
5267  * 4096MB: 8192k
5268  * 8192MB: 11584k
5269  * 16384MB: 16384k
5270  */
5272 {
5273  unsigned long lowmem_kbytes;
5274 
5275  lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
5276 
5277  min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
5278  if (min_free_kbytes < 128)
5279  min_free_kbytes = 128;
5280  if (min_free_kbytes > 65536)
5281  min_free_kbytes = 65536;
5283  refresh_zone_stat_thresholds();
5284  setup_per_zone_lowmem_reserve();
5285  setup_per_zone_inactive_ratio();
5286  return 0;
5287 }
5289 
5290 /*
5291  * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5292  * that we can call two helper functions whenever min_free_kbytes
5293  * changes.
5294  */
5295 int min_free_kbytes_sysctl_handler(ctl_table *table, int write,
5296  void __user *buffer, size_t *length, loff_t *ppos)
5297 {
5298  proc_dointvec(table, write, buffer, length, ppos);
5299  if (write)
5301  return 0;
5302 }
5303 
5304 #ifdef CONFIG_NUMA
5306  void __user *buffer, size_t *length, loff_t *ppos)
5307 {
5308  struct zone *zone;
5309  int rc;
5310 
5311  rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5312  if (rc)
5313  return rc;
5314 
5315  for_each_zone(zone)
5316  zone->min_unmapped_pages = (zone->present_pages *
5317  sysctl_min_unmapped_ratio) / 100;
5318  return 0;
5319 }
5320 
5321 int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
5322  void __user *buffer, size_t *length, loff_t *ppos)
5323 {
5324  struct zone *zone;
5325  int rc;
5326 
5327  rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5328  if (rc)
5329  return rc;
5330 
5331  for_each_zone(zone)
5332  zone->min_slab_pages = (zone->present_pages *
5333  sysctl_min_slab_ratio) / 100;
5334  return 0;
5335 }
5336 #endif
5337 
5338 /*
5339  * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5340  * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5341  * whenever sysctl_lowmem_reserve_ratio changes.
5342  *
5343  * The reserve ratio obviously has absolutely no relation with the
5344  * minimum watermarks. The lowmem reserve ratio can only make sense
5345  * if in function of the boot time zone sizes.
5346  */
5348  void __user *buffer, size_t *length, loff_t *ppos)
5349 {
5350  proc_dointvec_minmax(table, write, buffer, length, ppos);
5351  setup_per_zone_lowmem_reserve();
5352  return 0;
5353 }
5354 
5355 /*
5356  * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5357  * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
5358  * can have before it gets flushed back to buddy allocator.
5359  */
5360 
5362  void __user *buffer, size_t *length, loff_t *ppos)
5363 {
5364  struct zone *zone;
5365  unsigned int cpu;
5366  int ret;
5367 
5368  ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
5369  if (!write || (ret < 0))
5370  return ret;
5371  for_each_populated_zone(zone) {
5372  for_each_possible_cpu(cpu) {
5373  unsigned long high;
5374  high = zone->present_pages / percpu_pagelist_fraction;
5375  setup_pagelist_highmark(
5376  per_cpu_ptr(zone->pageset, cpu), high);
5377  }
5378  }
5379  return 0;
5380 }
5381 
5383 
5384 #ifdef CONFIG_NUMA
5385 static int __init set_hashdist(char *str)
5386 {
5387  if (!str)
5388  return 0;
5389  hashdist = simple_strtoul(str, &str, 0);
5390  return 1;
5391 }
5392 __setup("hashdist=", set_hashdist);
5393 #endif
5394 
5395 /*
5396  * allocate a large system hash table from bootmem
5397  * - it is assumed that the hash table must contain an exact power-of-2
5398  * quantity of entries
5399  * - limit is the number of hash buckets, not the total allocation size
5400  */
5401 void *__init alloc_large_system_hash(const char *tablename,
5402  unsigned long bucketsize,
5403  unsigned long numentries,
5404  int scale,
5405  int flags,
5406  unsigned int *_hash_shift,
5407  unsigned int *_hash_mask,
5408  unsigned long low_limit,
5409  unsigned long high_limit)
5410 {
5411  unsigned long long max = high_limit;
5412  unsigned long log2qty, size;
5413  void *table = NULL;
5414 
5415  /* allow the kernel cmdline to have a say */
5416  if (!numentries) {
5417  /* round applicable memory size up to nearest megabyte */
5418  numentries = nr_kernel_pages;
5419  numentries += (1UL << (20 - PAGE_SHIFT)) - 1;
5420  numentries >>= 20 - PAGE_SHIFT;
5421  numentries <<= 20 - PAGE_SHIFT;
5422 
5423  /* limit to 1 bucket per 2^scale bytes of low memory */
5424  if (scale > PAGE_SHIFT)
5425  numentries >>= (scale - PAGE_SHIFT);
5426  else
5427  numentries <<= (PAGE_SHIFT - scale);
5428 
5429  /* Make sure we've got at least a 0-order allocation.. */
5430  if (unlikely(flags & HASH_SMALL)) {
5431  /* Makes no sense without HASH_EARLY */
5432  WARN_ON(!(flags & HASH_EARLY));
5433  if (!(numentries >> *_hash_shift)) {
5434  numentries = 1UL << *_hash_shift;
5435  BUG_ON(!numentries);
5436  }
5437  } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
5438  numentries = PAGE_SIZE / bucketsize;
5439  }
5440  numentries = roundup_pow_of_two(numentries);
5441 
5442  /* limit allocation size to 1/16 total memory by default */
5443  if (max == 0) {
5444  max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
5445  do_div(max, bucketsize);
5446  }
5447  max = min(max, 0x80000000ULL);
5448 
5449  if (numentries < low_limit)
5450  numentries = low_limit;
5451  if (numentries > max)
5452  numentries = max;
5453 
5454  log2qty = ilog2(numentries);
5455 
5456  do {
5457  size = bucketsize << log2qty;
5458  if (flags & HASH_EARLY)
5459  table = alloc_bootmem_nopanic(size);
5460  else if (hashdist)
5461  table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
5462  else {
5463  /*
5464  * If bucketsize is not a power-of-two, we may free
5465  * some pages at the end of hash table which
5466  * alloc_pages_exact() automatically does
5467  */
5468  if (get_order(size) < MAX_ORDER) {
5469  table = alloc_pages_exact(size, GFP_ATOMIC);
5470  kmemleak_alloc(table, size, 1, GFP_ATOMIC);
5471  }
5472  }
5473  } while (!table && size > PAGE_SIZE && --log2qty);
5474 
5475  if (!table)
5476  panic("Failed to allocate %s hash table\n", tablename);
5477 
5478  printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n",
5479  tablename,
5480  (1UL << log2qty),
5481  ilog2(size) - PAGE_SHIFT,
5482  size);
5483 
5484  if (_hash_shift)
5485  *_hash_shift = log2qty;
5486  if (_hash_mask)
5487  *_hash_mask = (1 << log2qty) - 1;
5488 
5489  return table;
5490 }
5491 
5492 /* Return a pointer to the bitmap storing bits affecting a block of pages */
5493 static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
5494  unsigned long pfn)
5495 {
5496 #ifdef CONFIG_SPARSEMEM
5497  return __pfn_to_section(pfn)->pageblock_flags;
5498 #else
5499  return zone->pageblock_flags;
5500 #endif /* CONFIG_SPARSEMEM */
5501 }
5502 
5503 static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
5504 {
5505 #ifdef CONFIG_SPARSEMEM
5506  pfn &= (PAGES_PER_SECTION-1);
5507  return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5508 #else
5509  pfn = pfn - zone->zone_start_pfn;
5510  return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5511 #endif /* CONFIG_SPARSEMEM */
5512 }
5513 
5521 unsigned long get_pageblock_flags_group(struct page *page,
5522  int start_bitidx, int end_bitidx)
5523 {
5524  struct zone *zone;
5525  unsigned long *bitmap;
5526  unsigned long pfn, bitidx;
5527  unsigned long flags = 0;
5528  unsigned long value = 1;
5529 
5530  zone = page_zone(page);
5531  pfn = page_to_pfn(page);
5532  bitmap = get_pageblock_bitmap(zone, pfn);
5533  bitidx = pfn_to_bitidx(zone, pfn);
5534 
5535  for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
5536  if (test_bit(bitidx + start_bitidx, bitmap))
5537  flags |= value;
5538 
5539  return flags;
5540 }
5541 
5549 void set_pageblock_flags_group(struct page *page, unsigned long flags,
5550  int start_bitidx, int end_bitidx)
5551 {
5552  struct zone *zone;
5553  unsigned long *bitmap;
5554  unsigned long pfn, bitidx;
5555  unsigned long value = 1;
5556 
5557  zone = page_zone(page);
5558  pfn = page_to_pfn(page);
5559  bitmap = get_pageblock_bitmap(zone, pfn);
5560  bitidx = pfn_to_bitidx(zone, pfn);
5561  VM_BUG_ON(pfn < zone->zone_start_pfn);
5562  VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
5563 
5564  for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
5565  if (flags & value)
5566  __set_bit(bitidx + start_bitidx, bitmap);
5567  else
5568  __clear_bit(bitidx + start_bitidx, bitmap);
5569 }
5570 
5571 /*
5572  * This function checks whether pageblock includes unmovable pages or not.
5573  * If @count is not zero, it is okay to include less @count unmovable pages
5574  *
5575  * PageLRU check wihtout isolation or lru_lock could race so that
5576  * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
5577  * expect this function should be exact.
5578  */
5579 bool has_unmovable_pages(struct zone *zone, struct page *page, int count)
5580 {
5581  unsigned long pfn, iter, found;
5582  int mt;
5583 
5584  /*
5585  * For avoiding noise data, lru_add_drain_all() should be called
5586  * If ZONE_MOVABLE, the zone never contains unmovable pages
5587  */
5588  if (zone_idx(zone) == ZONE_MOVABLE)
5589  return false;
5590  mt = get_pageblock_migratetype(page);
5591  if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
5592  return false;
5593 
5594  pfn = page_to_pfn(page);
5595  for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
5596  unsigned long check = pfn + iter;
5597 
5598  if (!pfn_valid_within(check))
5599  continue;
5600 
5601  page = pfn_to_page(check);
5602  /*
5603  * We can't use page_count without pin a page
5604  * because another CPU can free compound page.
5605  * This check already skips compound tails of THP
5606  * because their page->_count is zero at all time.
5607  */
5608  if (!atomic_read(&page->_count)) {
5609  if (PageBuddy(page))
5610  iter += (1 << page_order(page)) - 1;
5611  continue;
5612  }
5613 
5614  if (!PageLRU(page))
5615  found++;
5616  /*
5617  * If there are RECLAIMABLE pages, we need to check it.
5618  * But now, memory offline itself doesn't call shrink_slab()
5619  * and it still to be fixed.
5620  */
5621  /*
5622  * If the page is not RAM, page_count()should be 0.
5623  * we don't need more check. This is an _used_ not-movable page.
5624  *
5625  * The problematic thing here is PG_reserved pages. PG_reserved
5626  * is set to both of a memory hole page and a _used_ kernel
5627  * page at boot.
5628  */
5629  if (found > count)
5630  return true;
5631  }
5632  return false;
5633 }
5634 
5635 bool is_pageblock_removable_nolock(struct page *page)
5636 {
5637  struct zone *zone;
5638  unsigned long pfn;
5639 
5640  /*
5641  * We have to be careful here because we are iterating over memory
5642  * sections which are not zone aware so we might end up outside of
5643  * the zone but still within the section.
5644  * We have to take care about the node as well. If the node is offline
5645  * its NODE_DATA will be NULL - see page_zone.
5646  */
5647  if (!node_online(page_to_nid(page)))
5648  return false;
5649 
5650  zone = page_zone(page);
5651  pfn = page_to_pfn(page);
5652  if (zone->zone_start_pfn > pfn ||
5653  zone->zone_start_pfn + zone->spanned_pages <= pfn)
5654  return false;
5655 
5656  return !has_unmovable_pages(zone, page, 0);
5657 }
5658 
5659 #ifdef CONFIG_CMA
5660 
5661 static unsigned long pfn_max_align_down(unsigned long pfn)
5662 {
5663  return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
5664  pageblock_nr_pages) - 1);
5665 }
5666 
5667 static unsigned long pfn_max_align_up(unsigned long pfn)
5668 {
5669  return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
5671 }
5672 
5673 /* [start, end) must belong to a single zone. */
5674 static int __alloc_contig_migrate_range(struct compact_control *cc,
5675  unsigned long start, unsigned long end)
5676 {
5677  /* This function is based on compact_zone() from compaction.c. */
5678  unsigned long nr_reclaimed;
5679  unsigned long pfn = start;
5680  unsigned int tries = 0;
5681  int ret = 0;
5682 
5684 
5685  while (pfn < end || !list_empty(&cc->migratepages)) {
5686  if (fatal_signal_pending(current)) {
5687  ret = -EINTR;
5688  break;
5689  }
5690 
5691  if (list_empty(&cc->migratepages)) {
5692  cc->nr_migratepages = 0;
5693  pfn = isolate_migratepages_range(cc->zone, cc,
5694  pfn, end, true);
5695  if (!pfn) {
5696  ret = -EINTR;
5697  break;
5698  }
5699  tries = 0;
5700  } else if (++tries == 5) {
5701  ret = ret < 0 ? ret : -EBUSY;
5702  break;
5703  }
5704 
5705  nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
5706  &cc->migratepages);
5707  cc->nr_migratepages -= nr_reclaimed;
5708 
5709  ret = migrate_pages(&cc->migratepages,
5711  0, false, MIGRATE_SYNC);
5712  }
5713 
5714  putback_lru_pages(&cc->migratepages);
5715  return ret > 0 ? 0 : ret;
5716 }
5717 
5718 /*
5719  * Update zone's cma pages counter used for watermark level calculation.
5720  */
5721 static inline void __update_cma_watermarks(struct zone *zone, int count)
5722 {
5723  unsigned long flags;
5724  spin_lock_irqsave(&zone->lock, flags);
5725  zone->min_cma_pages += count;
5726  spin_unlock_irqrestore(&zone->lock, flags);
5728 }
5729 
5730 /*
5731  * Trigger memory pressure bump to reclaim some pages in order to be able to
5732  * allocate 'count' pages in single page units. Does similar work as
5733  *__alloc_pages_slowpath() function.
5734  */
5735 static int __reclaim_pages(struct zone *zone, gfp_t gfp_mask, int count)
5736 {
5737  enum zone_type high_zoneidx = gfp_zone(gfp_mask);
5738  struct zonelist *zonelist = node_zonelist(0, gfp_mask);
5739  int did_some_progress = 0;
5740  int order = 1;
5741 
5742  /*
5743  * Increase level of watermarks to force kswapd do his job
5744  * to stabilise at new watermark level.
5745  */
5746  __update_cma_watermarks(zone, count);
5747 
5748  /* Obey watermarks as if the page was being allocated */
5749  while (!zone_watermark_ok(zone, 0, low_wmark_pages(zone), 0, 0)) {
5750  wake_all_kswapd(order, zonelist, high_zoneidx, zone_idx(zone));
5751 
5752  did_some_progress = __perform_reclaim(gfp_mask, order, zonelist,
5753  NULL);
5754  if (!did_some_progress) {
5755  /* Exhausted what can be done so it's blamo time */
5756  out_of_memory(zonelist, gfp_mask, order, NULL, false);
5757  }
5758  }
5759 
5760  /* Restore original watermark levels. */
5761  __update_cma_watermarks(zone, -count);
5762 
5763  return count;
5764 }
5765 
5786 int alloc_contig_range(unsigned long start, unsigned long end,
5787  unsigned migratetype)
5788 {
5789  struct zone *zone = page_zone(pfn_to_page(start));
5790  unsigned long outer_start, outer_end;
5791  int ret = 0, order;
5792 
5793  struct compact_control cc = {
5794  .nr_migratepages = 0,
5795  .order = -1,
5796  .zone = page_zone(pfn_to_page(start)),
5797  .sync = true,
5798  .ignore_skip_hint = true,
5799  };
5800  INIT_LIST_HEAD(&cc.migratepages);
5801 
5802  /*
5803  * What we do here is we mark all pageblocks in range as
5804  * MIGRATE_ISOLATE. Because pageblock and max order pages may
5805  * have different sizes, and due to the way page allocator
5806  * work, we align the range to biggest of the two pages so
5807  * that page allocator won't try to merge buddies from
5808  * different pageblocks and change MIGRATE_ISOLATE to some
5809  * other migration type.
5810  *
5811  * Once the pageblocks are marked as MIGRATE_ISOLATE, we
5812  * migrate the pages from an unaligned range (ie. pages that
5813  * we are interested in). This will put all the pages in
5814  * range back to page allocator as MIGRATE_ISOLATE.
5815  *
5816  * When this is done, we take the pages in range from page
5817  * allocator removing them from the buddy system. This way
5818  * page allocator will never consider using them.
5819  *
5820  * This lets us mark the pageblocks back as
5821  * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
5822  * aligned range but not in the unaligned, original range are
5823  * put back to page allocator so that buddy can use them.
5824  */
5825 
5826  ret = start_isolate_page_range(pfn_max_align_down(start),
5827  pfn_max_align_up(end), migratetype);
5828  if (ret)
5829  return ret;
5830 
5831  ret = __alloc_contig_migrate_range(&cc, start, end);
5832  if (ret)
5833  goto done;
5834 
5835  /*
5836  * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
5837  * aligned blocks that are marked as MIGRATE_ISOLATE. What's
5838  * more, all pages in [start, end) are free in page allocator.
5839  * What we are going to do is to allocate all pages from
5840  * [start, end) (that is remove them from page allocator).
5841  *
5842  * The only problem is that pages at the beginning and at the
5843  * end of interesting range may be not aligned with pages that
5844  * page allocator holds, ie. they can be part of higher order
5845  * pages. Because of this, we reserve the bigger range and
5846  * once this is done free the pages we are not interested in.
5847  *
5848  * We don't have to hold zone->lock here because the pages are
5849  * isolated thus they won't get removed from buddy.
5850  */
5851 
5853  drain_all_pages();
5854 
5855  order = 0;
5856  outer_start = start;
5857  while (!PageBuddy(pfn_to_page(outer_start))) {
5858  if (++order >= MAX_ORDER) {
5859  ret = -EBUSY;
5860  goto done;
5861  }
5862  outer_start &= ~0UL << order;
5863  }
5864 
5865  /* Make sure the range is really isolated. */
5866  if (test_pages_isolated(outer_start, end)) {
5867  pr_warn("alloc_contig_range test_pages_isolated(%lx, %lx) failed\n",
5868  outer_start, end);
5869  ret = -EBUSY;
5870  goto done;
5871  }
5872 
5873  /*
5874  * Reclaim enough pages to make sure that contiguous allocation
5875  * will not starve the system.
5876  */
5877  __reclaim_pages(zone, GFP_HIGHUSER_MOVABLE, end-start);
5878 
5879  /* Grab isolated pages from freelists. */
5880  outer_end = isolate_freepages_range(&cc, outer_start, end);
5881  if (!outer_end) {
5882  ret = -EBUSY;
5883  goto done;
5884  }
5885 
5886  /* Free head and tail (if any) */
5887  if (start != outer_start)
5888  free_contig_range(outer_start, start - outer_start);
5889  if (end != outer_end)
5890  free_contig_range(end, outer_end - end);
5891 
5892 done:
5893  undo_isolate_page_range(pfn_max_align_down(start),
5894  pfn_max_align_up(end), migratetype);
5895  return ret;
5896 }
5897 
5898 void free_contig_range(unsigned long pfn, unsigned nr_pages)
5899 {
5900  for (; nr_pages--; ++pfn)
5901  __free_page(pfn_to_page(pfn));
5902 }
5903 #endif
5904 
5905 #ifdef CONFIG_MEMORY_HOTPLUG
5906 static int __meminit __zone_pcp_update(void *data)
5907 {
5908  struct zone *zone = data;
5909  int cpu;
5910  unsigned long batch = zone_batchsize(zone), flags;
5911 
5912  for_each_possible_cpu(cpu) {
5913  struct per_cpu_pageset *pset;
5914  struct per_cpu_pages *pcp;
5915 
5916  pset = per_cpu_ptr(zone->pageset, cpu);
5917  pcp = &pset->pcp;
5918 
5919  local_irq_save(flags);
5920  if (pcp->count > 0)
5921  free_pcppages_bulk(zone, pcp->count, pcp);
5922  drain_zonestat(zone, pset);
5923  setup_pageset(pset, batch);
5924  local_irq_restore(flags);
5925  }
5926  return 0;
5927 }
5928 
5929 void __meminit zone_pcp_update(struct zone *zone)
5930 {
5931  stop_machine(__zone_pcp_update, zone, NULL);
5932 }
5933 #endif
5934 
5935 #ifdef CONFIG_MEMORY_HOTREMOVE
5936 void zone_pcp_reset(struct zone *zone)
5937 {
5938  unsigned long flags;
5939  int cpu;
5940  struct per_cpu_pageset *pset;
5941 
5942  /* avoid races with drain_pages() */
5943  local_irq_save(flags);
5944  if (zone->pageset != &boot_pageset) {
5945  for_each_online_cpu(cpu) {
5946  pset = per_cpu_ptr(zone->pageset, cpu);
5947  drain_zonestat(zone, pset);
5948  }
5949  free_percpu(zone->pageset);
5950  zone->pageset = &boot_pageset;
5951  }
5952  local_irq_restore(flags);
5953 }
5954 
5955 /*
5956  * All pages in the range must be isolated before calling this.
5957  */
5958 void
5959 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
5960 {
5961  struct page *page;
5962  struct zone *zone;
5963  int order, i;
5964  unsigned long pfn;
5965  unsigned long flags;
5966  /* find the first valid pfn */
5967  for (pfn = start_pfn; pfn < end_pfn; pfn++)
5968  if (pfn_valid(pfn))
5969  break;
5970  if (pfn == end_pfn)
5971  return;
5972  zone = page_zone(pfn_to_page(pfn));
5973  spin_lock_irqsave(&zone->lock, flags);
5974  pfn = start_pfn;
5975  while (pfn < end_pfn) {
5976  if (!pfn_valid(pfn)) {
5977  pfn++;
5978  continue;
5979  }
5980  page = pfn_to_page(pfn);
5981  BUG_ON(page_count(page));
5982  BUG_ON(!PageBuddy(page));
5983  order = page_order(page);
5984 #ifdef CONFIG_DEBUG_VM
5985  printk(KERN_INFO "remove from free list %lx %d %lx\n",
5986  pfn, 1 << order, end_pfn);
5987 #endif
5988  list_del(&page->lru);
5989  rmv_page_order(page);
5990  zone->free_area[order].nr_free--;
5991  __mod_zone_page_state(zone, NR_FREE_PAGES,
5992  - (1UL << order));
5993  for (i = 0; i < (1 << order); i++)
5994  SetPageReserved((page+i));
5995  pfn += (1 << order);
5996  }
5997  spin_unlock_irqrestore(&zone->lock, flags);
5998 }
5999 #endif
6000 
6001 #ifdef CONFIG_MEMORY_FAILURE
6002 bool is_free_buddy_page(struct page *page)
6003 {
6004  struct zone *zone = page_zone(page);
6005  unsigned long pfn = page_to_pfn(page);
6006  unsigned long flags;
6007  int order;
6008 
6009  spin_lock_irqsave(&zone->lock, flags);
6010  for (order = 0; order < MAX_ORDER; order++) {
6011  struct page *page_head = page - (pfn & ((1 << order) - 1));
6012 
6013  if (PageBuddy(page_head) && page_order(page_head) >= order)
6014  break;
6015  }
6016  spin_unlock_irqrestore(&zone->lock, flags);
6017 
6018  return order < MAX_ORDER;
6019 }
6020 #endif
6021 
6022 static const struct trace_print_flags pageflag_names[] = {
6023  {1UL << PG_locked, "locked" },
6024  {1UL << PG_error, "error" },
6025  {1UL << PG_referenced, "referenced" },
6026  {1UL << PG_uptodate, "uptodate" },
6027  {1UL << PG_dirty, "dirty" },
6028  {1UL << PG_lru, "lru" },
6029  {1UL << PG_active, "active" },
6030  {1UL << PG_slab, "slab" },
6031  {1UL << PG_owner_priv_1, "owner_priv_1" },
6032  {1UL << PG_arch_1, "arch_1" },
6033  {1UL << PG_reserved, "reserved" },
6034  {1UL << PG_private, "private" },
6035  {1UL << PG_private_2, "private_2" },
6036  {1UL << PG_writeback, "writeback" },
6037 #ifdef CONFIG_PAGEFLAGS_EXTENDED
6038  {1UL << PG_head, "head" },
6039  {1UL << PG_tail, "tail" },
6040 #else
6041  {1UL << PG_compound, "compound" },
6042 #endif
6043  {1UL << PG_swapcache, "swapcache" },
6044  {1UL << PG_mappedtodisk, "mappedtodisk" },
6045  {1UL << PG_reclaim, "reclaim" },
6046  {1UL << PG_swapbacked, "swapbacked" },
6047  {1UL << PG_unevictable, "unevictable" },
6048 #ifdef CONFIG_MMU
6049  {1UL << PG_mlocked, "mlocked" },
6050 #endif
6051 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
6052  {1UL << PG_uncached, "uncached" },
6053 #endif
6054 #ifdef CONFIG_MEMORY_FAILURE
6055  {1UL << PG_hwpoison, "hwpoison" },
6056 #endif
6057 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6058  {1UL << PG_compound_lock, "compound_lock" },
6059 #endif
6060 };
6061 
6062 static void dump_page_flags(unsigned long flags)
6063 {
6064  const char *delim = "";
6065  unsigned long mask;
6066  int i;
6067 
6068  BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS);
6069 
6070  printk(KERN_ALERT "page flags: %#lx(", flags);
6071 
6072  /* remove zone id */
6073  flags &= (1UL << NR_PAGEFLAGS) - 1;
6074 
6075  for (i = 0; i < ARRAY_SIZE(pageflag_names) && flags; i++) {
6076 
6077  mask = pageflag_names[i].mask;
6078  if ((flags & mask) != mask)
6079  continue;
6080 
6081  flags &= ~mask;
6082  printk("%s%s", delim, pageflag_names[i].name);
6083  delim = "|";
6084  }
6085 
6086  /* check for left over flags */
6087  if (flags)
6088  printk("%s%#lx", delim, flags);
6089 
6090  printk(")\n");
6091 }
6092 
6093 void dump_page(struct page *page)
6094 {
6096  "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
6097  page, atomic_read(&page->_count), page_mapcount(page),
6098  page->mapping, page->index);
6099  dump_page_flags(page->flags);
6100  mem_cgroup_print_bad_page(page);
6101 }