759d3f60bea01a245aafc836cac92a796571a9f8
[deliverable/linux.git] / mm / page_alloc.c
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/kasan.h>
29 #include <linux/module.h>
30 #include <linux/suspend.h>
31 #include <linux/pagevec.h>
32 #include <linux/blkdev.h>
33 #include <linux/slab.h>
34 #include <linux/ratelimit.h>
35 #include <linux/oom.h>
36 #include <linux/notifier.h>
37 #include <linux/topology.h>
38 #include <linux/sysctl.h>
39 #include <linux/cpu.h>
40 #include <linux/cpuset.h>
41 #include <linux/memory_hotplug.h>
42 #include <linux/nodemask.h>
43 #include <linux/vmalloc.h>
44 #include <linux/vmstat.h>
45 #include <linux/mempolicy.h>
46 #include <linux/memremap.h>
47 #include <linux/stop_machine.h>
48 #include <linux/sort.h>
49 #include <linux/pfn.h>
50 #include <linux/backing-dev.h>
51 #include <linux/fault-inject.h>
52 #include <linux/page-isolation.h>
53 #include <linux/page_ext.h>
54 #include <linux/debugobjects.h>
55 #include <linux/kmemleak.h>
56 #include <linux/compaction.h>
57 #include <trace/events/kmem.h>
58 #include <linux/prefetch.h>
59 #include <linux/mm_inline.h>
60 #include <linux/migrate.h>
61 #include <linux/page_ext.h>
62 #include <linux/hugetlb.h>
63 #include <linux/sched/rt.h>
64 #include <linux/page_owner.h>
65 #include <linux/kthread.h>
66
67 #include <asm/sections.h>
68 #include <asm/tlbflush.h>
69 #include <asm/div64.h>
70 #include "internal.h"
71
72 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
73 static DEFINE_MUTEX(pcp_batch_high_lock);
74 #define MIN_PERCPU_PAGELIST_FRACTION (8)
75
76 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
77 DEFINE_PER_CPU(int, numa_node);
78 EXPORT_PER_CPU_SYMBOL(numa_node);
79 #endif
80
81 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
82 /*
83 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
84 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
85 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
86 * defined in <linux/topology.h>.
87 */
88 DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */
89 EXPORT_PER_CPU_SYMBOL(_numa_mem_);
90 int _node_numa_mem_[MAX_NUMNODES];
91 #endif
92
93 /*
94 * Array of node states.
95 */
96 nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
97 [N_POSSIBLE] = NODE_MASK_ALL,
98 [N_ONLINE] = { { [0] = 1UL } },
99 #ifndef CONFIG_NUMA
100 [N_NORMAL_MEMORY] = { { [0] = 1UL } },
101 #ifdef CONFIG_HIGHMEM
102 [N_HIGH_MEMORY] = { { [0] = 1UL } },
103 #endif
104 #ifdef CONFIG_MOVABLE_NODE
105 [N_MEMORY] = { { [0] = 1UL } },
106 #endif
107 [N_CPU] = { { [0] = 1UL } },
108 #endif /* NUMA */
109 };
110 EXPORT_SYMBOL(node_states);
111
112 /* Protect totalram_pages and zone->managed_pages */
113 static DEFINE_SPINLOCK(managed_page_count_lock);
114
115 unsigned long totalram_pages __read_mostly;
116 unsigned long totalreserve_pages __read_mostly;
117 unsigned long totalcma_pages __read_mostly;
118
119 int percpu_pagelist_fraction;
120 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
121
122 /*
123 * A cached value of the page's pageblock's migratetype, used when the page is
124 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
125 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
126 * Also the migratetype set in the page does not necessarily match the pcplist
127 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
128 * other index - this ensures that it will be put on the correct CMA freelist.
129 */
130 static inline int get_pcppage_migratetype(struct page *page)
131 {
132 return page->index;
133 }
134
135 static inline void set_pcppage_migratetype(struct page *page, int migratetype)
136 {
137 page->index = migratetype;
138 }
139
140 #ifdef CONFIG_PM_SLEEP
141 /*
142 * The following functions are used by the suspend/hibernate code to temporarily
143 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
144 * while devices are suspended. To avoid races with the suspend/hibernate code,
145 * they should always be called with pm_mutex held (gfp_allowed_mask also should
146 * only be modified with pm_mutex held, unless the suspend/hibernate code is
147 * guaranteed not to run in parallel with that modification).
148 */
149
150 static gfp_t saved_gfp_mask;
151
152 void pm_restore_gfp_mask(void)
153 {
154 WARN_ON(!mutex_is_locked(&pm_mutex));
155 if (saved_gfp_mask) {
156 gfp_allowed_mask = saved_gfp_mask;
157 saved_gfp_mask = 0;
158 }
159 }
160
161 void pm_restrict_gfp_mask(void)
162 {
163 WARN_ON(!mutex_is_locked(&pm_mutex));
164 WARN_ON(saved_gfp_mask);
165 saved_gfp_mask = gfp_allowed_mask;
166 gfp_allowed_mask &= ~(__GFP_IO | __GFP_FS);
167 }
168
169 bool pm_suspended_storage(void)
170 {
171 if ((gfp_allowed_mask & (__GFP_IO | __GFP_FS)) == (__GFP_IO | __GFP_FS))
172 return false;
173 return true;
174 }
175 #endif /* CONFIG_PM_SLEEP */
176
177 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
178 unsigned int pageblock_order __read_mostly;
179 #endif
180
181 static void __free_pages_ok(struct page *page, unsigned int order);
182
183 /*
184 * results with 256, 32 in the lowmem_reserve sysctl:
185 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
186 * 1G machine -> (16M dma, 784M normal, 224M high)
187 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
188 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
189 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
190 *
191 * TBD: should special case ZONE_DMA32 machines here - in those we normally
192 * don't need any ZONE_NORMAL reservation
193 */
194 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
195 #ifdef CONFIG_ZONE_DMA
196 256,
197 #endif
198 #ifdef CONFIG_ZONE_DMA32
199 256,
200 #endif
201 #ifdef CONFIG_HIGHMEM
202 32,
203 #endif
204 32,
205 };
206
207 EXPORT_SYMBOL(totalram_pages);
208
209 static char * const zone_names[MAX_NR_ZONES] = {
210 #ifdef CONFIG_ZONE_DMA
211 "DMA",
212 #endif
213 #ifdef CONFIG_ZONE_DMA32
214 "DMA32",
215 #endif
216 "Normal",
217 #ifdef CONFIG_HIGHMEM
218 "HighMem",
219 #endif
220 "Movable",
221 #ifdef CONFIG_ZONE_DEVICE
222 "Device",
223 #endif
224 };
225
226 char * const migratetype_names[MIGRATE_TYPES] = {
227 "Unmovable",
228 "Movable",
229 "Reclaimable",
230 "HighAtomic",
231 #ifdef CONFIG_CMA
232 "CMA",
233 #endif
234 #ifdef CONFIG_MEMORY_ISOLATION
235 "Isolate",
236 #endif
237 };
238
239 compound_page_dtor * const compound_page_dtors[] = {
240 NULL,
241 free_compound_page,
242 #ifdef CONFIG_HUGETLB_PAGE
243 free_huge_page,
244 #endif
245 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
246 free_transhuge_page,
247 #endif
248 };
249
250 int min_free_kbytes = 1024;
251 int user_min_free_kbytes = -1;
252 int watermark_scale_factor = 10;
253
254 static unsigned long __meminitdata nr_kernel_pages;
255 static unsigned long __meminitdata nr_all_pages;
256 static unsigned long __meminitdata dma_reserve;
257
258 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
259 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
260 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
261 static unsigned long __initdata required_kernelcore;
262 static unsigned long __initdata required_movablecore;
263 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
264 static bool mirrored_kernelcore;
265
266 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
267 int movable_zone;
268 EXPORT_SYMBOL(movable_zone);
269 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
270
271 #if MAX_NUMNODES > 1
272 int nr_node_ids __read_mostly = MAX_NUMNODES;
273 int nr_online_nodes __read_mostly = 1;
274 EXPORT_SYMBOL(nr_node_ids);
275 EXPORT_SYMBOL(nr_online_nodes);
276 #endif
277
278 int page_group_by_mobility_disabled __read_mostly;
279
280 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
281 static inline void reset_deferred_meminit(pg_data_t *pgdat)
282 {
283 pgdat->first_deferred_pfn = ULONG_MAX;
284 }
285
286 /* Returns true if the struct page for the pfn is uninitialised */
287 static inline bool __meminit early_page_uninitialised(unsigned long pfn)
288 {
289 if (pfn >= NODE_DATA(early_pfn_to_nid(pfn))->first_deferred_pfn)
290 return true;
291
292 return false;
293 }
294
295 static inline bool early_page_nid_uninitialised(unsigned long pfn, int nid)
296 {
297 if (pfn >= NODE_DATA(nid)->first_deferred_pfn)
298 return true;
299
300 return false;
301 }
302
303 /*
304 * Returns false when the remaining initialisation should be deferred until
305 * later in the boot cycle when it can be parallelised.
306 */
307 static inline bool update_defer_init(pg_data_t *pgdat,
308 unsigned long pfn, unsigned long zone_end,
309 unsigned long *nr_initialised)
310 {
311 unsigned long max_initialise;
312
313 /* Always populate low zones for address-contrained allocations */
314 if (zone_end < pgdat_end_pfn(pgdat))
315 return true;
316 /*
317 * Initialise at least 2G of a node but also take into account that
318 * two large system hashes that can take up 1GB for 0.25TB/node.
319 */
320 max_initialise = max(2UL << (30 - PAGE_SHIFT),
321 (pgdat->node_spanned_pages >> 8));
322
323 (*nr_initialised)++;
324 if ((*nr_initialised > max_initialise) &&
325 (pfn & (PAGES_PER_SECTION - 1)) == 0) {
326 pgdat->first_deferred_pfn = pfn;
327 return false;
328 }
329
330 return true;
331 }
332 #else
333 static inline void reset_deferred_meminit(pg_data_t *pgdat)
334 {
335 }
336
337 static inline bool early_page_uninitialised(unsigned long pfn)
338 {
339 return false;
340 }
341
342 static inline bool early_page_nid_uninitialised(unsigned long pfn, int nid)
343 {
344 return false;
345 }
346
347 static inline bool update_defer_init(pg_data_t *pgdat,
348 unsigned long pfn, unsigned long zone_end,
349 unsigned long *nr_initialised)
350 {
351 return true;
352 }
353 #endif
354
355 /* Return a pointer to the bitmap storing bits affecting a block of pages */
356 static inline unsigned long *get_pageblock_bitmap(struct page *page,
357 unsigned long pfn)
358 {
359 #ifdef CONFIG_SPARSEMEM
360 return __pfn_to_section(pfn)->pageblock_flags;
361 #else
362 return page_zone(page)->pageblock_flags;
363 #endif /* CONFIG_SPARSEMEM */
364 }
365
366 static inline int pfn_to_bitidx(struct page *page, unsigned long pfn)
367 {
368 #ifdef CONFIG_SPARSEMEM
369 pfn &= (PAGES_PER_SECTION-1);
370 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
371 #else
372 pfn = pfn - round_down(page_zone(page)->zone_start_pfn, pageblock_nr_pages);
373 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
374 #endif /* CONFIG_SPARSEMEM */
375 }
376
377 /**
378 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
379 * @page: The page within the block of interest
380 * @pfn: The target page frame number
381 * @end_bitidx: The last bit of interest to retrieve
382 * @mask: mask of bits that the caller is interested in
383 *
384 * Return: pageblock_bits flags
385 */
386 static __always_inline unsigned long __get_pfnblock_flags_mask(struct page *page,
387 unsigned long pfn,
388 unsigned long end_bitidx,
389 unsigned long mask)
390 {
391 unsigned long *bitmap;
392 unsigned long bitidx, word_bitidx;
393 unsigned long word;
394
395 bitmap = get_pageblock_bitmap(page, pfn);
396 bitidx = pfn_to_bitidx(page, pfn);
397 word_bitidx = bitidx / BITS_PER_LONG;
398 bitidx &= (BITS_PER_LONG-1);
399
400 word = bitmap[word_bitidx];
401 bitidx += end_bitidx;
402 return (word >> (BITS_PER_LONG - bitidx - 1)) & mask;
403 }
404
405 unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
406 unsigned long end_bitidx,
407 unsigned long mask)
408 {
409 return __get_pfnblock_flags_mask(page, pfn, end_bitidx, mask);
410 }
411
412 static __always_inline int get_pfnblock_migratetype(struct page *page, unsigned long pfn)
413 {
414 return __get_pfnblock_flags_mask(page, pfn, PB_migrate_end, MIGRATETYPE_MASK);
415 }
416
417 /**
418 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
419 * @page: The page within the block of interest
420 * @flags: The flags to set
421 * @pfn: The target page frame number
422 * @end_bitidx: The last bit of interest
423 * @mask: mask of bits that the caller is interested in
424 */
425 void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
426 unsigned long pfn,
427 unsigned long end_bitidx,
428 unsigned long mask)
429 {
430 unsigned long *bitmap;
431 unsigned long bitidx, word_bitidx;
432 unsigned long old_word, word;
433
434 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
435
436 bitmap = get_pageblock_bitmap(page, pfn);
437 bitidx = pfn_to_bitidx(page, pfn);
438 word_bitidx = bitidx / BITS_PER_LONG;
439 bitidx &= (BITS_PER_LONG-1);
440
441 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page);
442
443 bitidx += end_bitidx;
444 mask <<= (BITS_PER_LONG - bitidx - 1);
445 flags <<= (BITS_PER_LONG - bitidx - 1);
446
447 word = READ_ONCE(bitmap[word_bitidx]);
448 for (;;) {
449 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags);
450 if (word == old_word)
451 break;
452 word = old_word;
453 }
454 }
455
456 void set_pageblock_migratetype(struct page *page, int migratetype)
457 {
458 if (unlikely(page_group_by_mobility_disabled &&
459 migratetype < MIGRATE_PCPTYPES))
460 migratetype = MIGRATE_UNMOVABLE;
461
462 set_pageblock_flags_group(page, (unsigned long)migratetype,
463 PB_migrate, PB_migrate_end);
464 }
465
466 #ifdef CONFIG_DEBUG_VM
467 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
468 {
469 int ret = 0;
470 unsigned seq;
471 unsigned long pfn = page_to_pfn(page);
472 unsigned long sp, start_pfn;
473
474 do {
475 seq = zone_span_seqbegin(zone);
476 start_pfn = zone->zone_start_pfn;
477 sp = zone->spanned_pages;
478 if (!zone_spans_pfn(zone, pfn))
479 ret = 1;
480 } while (zone_span_seqretry(zone, seq));
481
482 if (ret)
483 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
484 pfn, zone_to_nid(zone), zone->name,
485 start_pfn, start_pfn + sp);
486
487 return ret;
488 }
489
490 static int page_is_consistent(struct zone *zone, struct page *page)
491 {
492 if (!pfn_valid_within(page_to_pfn(page)))
493 return 0;
494 if (zone != page_zone(page))
495 return 0;
496
497 return 1;
498 }
499 /*
500 * Temporary debugging check for pages not lying within a given zone.
501 */
502 static int bad_range(struct zone *zone, struct page *page)
503 {
504 if (page_outside_zone_boundaries(zone, page))
505 return 1;
506 if (!page_is_consistent(zone, page))
507 return 1;
508
509 return 0;
510 }
511 #else
512 static inline int bad_range(struct zone *zone, struct page *page)
513 {
514 return 0;
515 }
516 #endif
517
518 static void bad_page(struct page *page, const char *reason,
519 unsigned long bad_flags)
520 {
521 static unsigned long resume;
522 static unsigned long nr_shown;
523 static unsigned long nr_unshown;
524
525 /* Don't complain about poisoned pages */
526 if (PageHWPoison(page)) {
527 page_mapcount_reset(page); /* remove PageBuddy */
528 return;
529 }
530
531 /*
532 * Allow a burst of 60 reports, then keep quiet for that minute;
533 * or allow a steady drip of one report per second.
534 */
535 if (nr_shown == 60) {
536 if (time_before(jiffies, resume)) {
537 nr_unshown++;
538 goto out;
539 }
540 if (nr_unshown) {
541 pr_alert(
542 "BUG: Bad page state: %lu messages suppressed\n",
543 nr_unshown);
544 nr_unshown = 0;
545 }
546 nr_shown = 0;
547 }
548 if (nr_shown++ == 0)
549 resume = jiffies + 60 * HZ;
550
551 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
552 current->comm, page_to_pfn(page));
553 __dump_page(page, reason);
554 bad_flags &= page->flags;
555 if (bad_flags)
556 pr_alert("bad because of flags: %#lx(%pGp)\n",
557 bad_flags, &bad_flags);
558 dump_page_owner(page);
559
560 print_modules();
561 dump_stack();
562 out:
563 /* Leave bad fields for debug, except PageBuddy could make trouble */
564 page_mapcount_reset(page); /* remove PageBuddy */
565 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
566 }
567
568 /*
569 * Higher-order pages are called "compound pages". They are structured thusly:
570 *
571 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
572 *
573 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
574 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
575 *
576 * The first tail page's ->compound_dtor holds the offset in array of compound
577 * page destructors. See compound_page_dtors.
578 *
579 * The first tail page's ->compound_order holds the order of allocation.
580 * This usage means that zero-order pages may not be compound.
581 */
582
583 void free_compound_page(struct page *page)
584 {
585 __free_pages_ok(page, compound_order(page));
586 }
587
588 void prep_compound_page(struct page *page, unsigned int order)
589 {
590 int i;
591 int nr_pages = 1 << order;
592
593 set_compound_page_dtor(page, COMPOUND_PAGE_DTOR);
594 set_compound_order(page, order);
595 __SetPageHead(page);
596 for (i = 1; i < nr_pages; i++) {
597 struct page *p = page + i;
598 set_page_count(p, 0);
599 p->mapping = TAIL_MAPPING;
600 set_compound_head(p, page);
601 }
602 atomic_set(compound_mapcount_ptr(page), -1);
603 }
604
605 #ifdef CONFIG_DEBUG_PAGEALLOC
606 unsigned int _debug_guardpage_minorder;
607 bool _debug_pagealloc_enabled __read_mostly
608 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT);
609 EXPORT_SYMBOL(_debug_pagealloc_enabled);
610 bool _debug_guardpage_enabled __read_mostly;
611
612 static int __init early_debug_pagealloc(char *buf)
613 {
614 if (!buf)
615 return -EINVAL;
616
617 if (strcmp(buf, "on") == 0)
618 _debug_pagealloc_enabled = true;
619
620 if (strcmp(buf, "off") == 0)
621 _debug_pagealloc_enabled = false;
622
623 return 0;
624 }
625 early_param("debug_pagealloc", early_debug_pagealloc);
626
627 static bool need_debug_guardpage(void)
628 {
629 /* If we don't use debug_pagealloc, we don't need guard page */
630 if (!debug_pagealloc_enabled())
631 return false;
632
633 return true;
634 }
635
636 static void init_debug_guardpage(void)
637 {
638 if (!debug_pagealloc_enabled())
639 return;
640
641 _debug_guardpage_enabled = true;
642 }
643
644 struct page_ext_operations debug_guardpage_ops = {
645 .need = need_debug_guardpage,
646 .init = init_debug_guardpage,
647 };
648
649 static int __init debug_guardpage_minorder_setup(char *buf)
650 {
651 unsigned long res;
652
653 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
654 pr_err("Bad debug_guardpage_minorder value\n");
655 return 0;
656 }
657 _debug_guardpage_minorder = res;
658 pr_info("Setting debug_guardpage_minorder to %lu\n", res);
659 return 0;
660 }
661 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup);
662
663 static inline void set_page_guard(struct zone *zone, struct page *page,
664 unsigned int order, int migratetype)
665 {
666 struct page_ext *page_ext;
667
668 if (!debug_guardpage_enabled())
669 return;
670
671 page_ext = lookup_page_ext(page);
672 __set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
673
674 INIT_LIST_HEAD(&page->lru);
675 set_page_private(page, order);
676 /* Guard pages are not available for any usage */
677 __mod_zone_freepage_state(zone, -(1 << order), migratetype);
678 }
679
680 static inline void clear_page_guard(struct zone *zone, struct page *page,
681 unsigned int order, int migratetype)
682 {
683 struct page_ext *page_ext;
684
685 if (!debug_guardpage_enabled())
686 return;
687
688 page_ext = lookup_page_ext(page);
689 __clear_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
690
691 set_page_private(page, 0);
692 if (!is_migrate_isolate(migratetype))
693 __mod_zone_freepage_state(zone, (1 << order), migratetype);
694 }
695 #else
696 struct page_ext_operations debug_guardpage_ops = { NULL, };
697 static inline void set_page_guard(struct zone *zone, struct page *page,
698 unsigned int order, int migratetype) {}
699 static inline void clear_page_guard(struct zone *zone, struct page *page,
700 unsigned int order, int migratetype) {}
701 #endif
702
703 static inline void set_page_order(struct page *page, unsigned int order)
704 {
705 set_page_private(page, order);
706 __SetPageBuddy(page);
707 }
708
709 static inline void rmv_page_order(struct page *page)
710 {
711 __ClearPageBuddy(page);
712 set_page_private(page, 0);
713 }
714
715 /*
716 * This function checks whether a page is free && is the buddy
717 * we can do coalesce a page and its buddy if
718 * (a) the buddy is not in a hole &&
719 * (b) the buddy is in the buddy system &&
720 * (c) a page and its buddy have the same order &&
721 * (d) a page and its buddy are in the same zone.
722 *
723 * For recording whether a page is in the buddy system, we set ->_mapcount
724 * PAGE_BUDDY_MAPCOUNT_VALUE.
725 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
726 * serialized by zone->lock.
727 *
728 * For recording page's order, we use page_private(page).
729 */
730 static inline int page_is_buddy(struct page *page, struct page *buddy,
731 unsigned int order)
732 {
733 if (!pfn_valid_within(page_to_pfn(buddy)))
734 return 0;
735
736 if (page_is_guard(buddy) && page_order(buddy) == order) {
737 if (page_zone_id(page) != page_zone_id(buddy))
738 return 0;
739
740 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
741
742 return 1;
743 }
744
745 if (PageBuddy(buddy) && page_order(buddy) == order) {
746 /*
747 * zone check is done late to avoid uselessly
748 * calculating zone/node ids for pages that could
749 * never merge.
750 */
751 if (page_zone_id(page) != page_zone_id(buddy))
752 return 0;
753
754 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
755
756 return 1;
757 }
758 return 0;
759 }
760
761 /*
762 * Freeing function for a buddy system allocator.
763 *
764 * The concept of a buddy system is to maintain direct-mapped table
765 * (containing bit values) for memory blocks of various "orders".
766 * The bottom level table contains the map for the smallest allocatable
767 * units of memory (here, pages), and each level above it describes
768 * pairs of units from the levels below, hence, "buddies".
769 * At a high level, all that happens here is marking the table entry
770 * at the bottom level available, and propagating the changes upward
771 * as necessary, plus some accounting needed to play nicely with other
772 * parts of the VM system.
773 * At each level, we keep a list of pages, which are heads of continuous
774 * free pages of length of (1 << order) and marked with _mapcount
775 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
776 * field.
777 * So when we are allocating or freeing one, we can derive the state of the
778 * other. That is, if we allocate a small block, and both were
779 * free, the remainder of the region must be split into blocks.
780 * If a block is freed, and its buddy is also free, then this
781 * triggers coalescing into a block of larger size.
782 *
783 * -- nyc
784 */
785
786 static inline void __free_one_page(struct page *page,
787 unsigned long pfn,
788 struct zone *zone, unsigned int order,
789 int migratetype)
790 {
791 unsigned long page_idx;
792 unsigned long combined_idx;
793 unsigned long uninitialized_var(buddy_idx);
794 struct page *buddy;
795 unsigned int max_order;
796
797 max_order = min_t(unsigned int, MAX_ORDER, pageblock_order + 1);
798
799 VM_BUG_ON(!zone_is_initialized(zone));
800 VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
801
802 VM_BUG_ON(migratetype == -1);
803 if (likely(!is_migrate_isolate(migratetype)))
804 __mod_zone_freepage_state(zone, 1 << order, migratetype);
805
806 page_idx = pfn & ((1 << MAX_ORDER) - 1);
807
808 VM_BUG_ON_PAGE(page_idx & ((1 << order) - 1), page);
809 VM_BUG_ON_PAGE(bad_range(zone, page), page);
810
811 continue_merging:
812 while (order < max_order - 1) {
813 buddy_idx = __find_buddy_index(page_idx, order);
814 buddy = page + (buddy_idx - page_idx);
815 if (!page_is_buddy(page, buddy, order))
816 goto done_merging;
817 /*
818 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
819 * merge with it and move up one order.
820 */
821 if (page_is_guard(buddy)) {
822 clear_page_guard(zone, buddy, order, migratetype);
823 } else {
824 list_del(&buddy->lru);
825 zone->free_area[order].nr_free--;
826 rmv_page_order(buddy);
827 }
828 combined_idx = buddy_idx & page_idx;
829 page = page + (combined_idx - page_idx);
830 page_idx = combined_idx;
831 order++;
832 }
833 if (max_order < MAX_ORDER) {
834 /* If we are here, it means order is >= pageblock_order.
835 * We want to prevent merge between freepages on isolate
836 * pageblock and normal pageblock. Without this, pageblock
837 * isolation could cause incorrect freepage or CMA accounting.
838 *
839 * We don't want to hit this code for the more frequent
840 * low-order merging.
841 */
842 if (unlikely(has_isolate_pageblock(zone))) {
843 int buddy_mt;
844
845 buddy_idx = __find_buddy_index(page_idx, order);
846 buddy = page + (buddy_idx - page_idx);
847 buddy_mt = get_pageblock_migratetype(buddy);
848
849 if (migratetype != buddy_mt
850 && (is_migrate_isolate(migratetype) ||
851 is_migrate_isolate(buddy_mt)))
852 goto done_merging;
853 }
854 max_order++;
855 goto continue_merging;
856 }
857
858 done_merging:
859 set_page_order(page, order);
860
861 /*
862 * If this is not the largest possible page, check if the buddy
863 * of the next-highest order is free. If it is, it's possible
864 * that pages are being freed that will coalesce soon. In case,
865 * that is happening, add the free page to the tail of the list
866 * so it's less likely to be used soon and more likely to be merged
867 * as a higher order page
868 */
869 if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
870 struct page *higher_page, *higher_buddy;
871 combined_idx = buddy_idx & page_idx;
872 higher_page = page + (combined_idx - page_idx);
873 buddy_idx = __find_buddy_index(combined_idx, order + 1);
874 higher_buddy = higher_page + (buddy_idx - combined_idx);
875 if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
876 list_add_tail(&page->lru,
877 &zone->free_area[order].free_list[migratetype]);
878 goto out;
879 }
880 }
881
882 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
883 out:
884 zone->free_area[order].nr_free++;
885 }
886
887 /*
888 * A bad page could be due to a number of fields. Instead of multiple branches,
889 * try and check multiple fields with one check. The caller must do a detailed
890 * check if necessary.
891 */
892 static inline bool page_expected_state(struct page *page,
893 unsigned long check_flags)
894 {
895 if (unlikely(atomic_read(&page->_mapcount) != -1))
896 return false;
897
898 if (unlikely((unsigned long)page->mapping |
899 page_ref_count(page) |
900 #ifdef CONFIG_MEMCG
901 (unsigned long)page->mem_cgroup |
902 #endif
903 (page->flags & check_flags)))
904 return false;
905
906 return true;
907 }
908
909 static void free_pages_check_bad(struct page *page)
910 {
911 const char *bad_reason;
912 unsigned long bad_flags;
913
914 bad_reason = NULL;
915 bad_flags = 0;
916
917 if (unlikely(atomic_read(&page->_mapcount) != -1))
918 bad_reason = "nonzero mapcount";
919 if (unlikely(page->mapping != NULL))
920 bad_reason = "non-NULL mapping";
921 if (unlikely(page_ref_count(page) != 0))
922 bad_reason = "nonzero _refcount";
923 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) {
924 bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
925 bad_flags = PAGE_FLAGS_CHECK_AT_FREE;
926 }
927 #ifdef CONFIG_MEMCG
928 if (unlikely(page->mem_cgroup))
929 bad_reason = "page still charged to cgroup";
930 #endif
931 bad_page(page, bad_reason, bad_flags);
932 }
933
934 static inline int free_pages_check(struct page *page)
935 {
936 if (likely(page_expected_state(page, PAGE_FLAGS_CHECK_AT_FREE)))
937 return 0;
938
939 /* Something has gone sideways, find it */
940 free_pages_check_bad(page);
941 return 1;
942 }
943
944 static int free_tail_pages_check(struct page *head_page, struct page *page)
945 {
946 int ret = 1;
947
948 /*
949 * We rely page->lru.next never has bit 0 set, unless the page
950 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
951 */
952 BUILD_BUG_ON((unsigned long)LIST_POISON1 & 1);
953
954 if (!IS_ENABLED(CONFIG_DEBUG_VM)) {
955 ret = 0;
956 goto out;
957 }
958 switch (page - head_page) {
959 case 1:
960 /* the first tail page: ->mapping is compound_mapcount() */
961 if (unlikely(compound_mapcount(page))) {
962 bad_page(page, "nonzero compound_mapcount", 0);
963 goto out;
964 }
965 break;
966 case 2:
967 /*
968 * the second tail page: ->mapping is
969 * page_deferred_list().next -- ignore value.
970 */
971 break;
972 default:
973 if (page->mapping != TAIL_MAPPING) {
974 bad_page(page, "corrupted mapping in tail page", 0);
975 goto out;
976 }
977 break;
978 }
979 if (unlikely(!PageTail(page))) {
980 bad_page(page, "PageTail not set", 0);
981 goto out;
982 }
983 if (unlikely(compound_head(page) != head_page)) {
984 bad_page(page, "compound_head not consistent", 0);
985 goto out;
986 }
987 ret = 0;
988 out:
989 page->mapping = NULL;
990 clear_compound_head(page);
991 return ret;
992 }
993
994 static bool free_pages_prepare(struct page *page, unsigned int order);
995
996 #ifdef CONFIG_DEBUG_VM
997 static inline bool free_pcp_prepare(struct page *page)
998 {
999 return free_pages_prepare(page, 0);
1000 }
1001
1002 static inline bool bulkfree_pcp_prepare(struct page *page)
1003 {
1004 return false;
1005 }
1006 #else
1007 static bool free_pcp_prepare(struct page *page)
1008 {
1009 VM_BUG_ON_PAGE(PageTail(page), page);
1010
1011 trace_mm_page_free(page, 0);
1012 kmemcheck_free_shadow(page, 0);
1013 kasan_free_pages(page, 0);
1014
1015 if (PageAnonHead(page))
1016 page->mapping = NULL;
1017
1018 reset_page_owner(page, 0);
1019
1020 if (!PageHighMem(page)) {
1021 debug_check_no_locks_freed(page_address(page),
1022 PAGE_SIZE);
1023 debug_check_no_obj_freed(page_address(page),
1024 PAGE_SIZE);
1025 }
1026 arch_free_page(page, 0);
1027 kernel_poison_pages(page, 0, 0);
1028 kernel_map_pages(page, 0, 0);
1029
1030 page_cpupid_reset_last(page);
1031 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1032 return true;
1033 }
1034
1035 static bool bulkfree_pcp_prepare(struct page *page)
1036 {
1037 return free_pages_check(page);
1038 }
1039 #endif /* CONFIG_DEBUG_VM */
1040
1041 /*
1042 * Frees a number of pages from the PCP lists
1043 * Assumes all pages on list are in same zone, and of same order.
1044 * count is the number of pages to free.
1045 *
1046 * If the zone was previously in an "all pages pinned" state then look to
1047 * see if this freeing clears that state.
1048 *
1049 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1050 * pinned" detection logic.
1051 */
1052 static void free_pcppages_bulk(struct zone *zone, int count,
1053 struct per_cpu_pages *pcp)
1054 {
1055 int migratetype = 0;
1056 int batch_free = 0;
1057 unsigned long nr_scanned;
1058 bool isolated_pageblocks;
1059
1060 spin_lock(&zone->lock);
1061 isolated_pageblocks = has_isolate_pageblock(zone);
1062 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
1063 if (nr_scanned)
1064 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
1065
1066 while (count) {
1067 struct page *page;
1068 struct list_head *list;
1069
1070 /*
1071 * Remove pages from lists in a round-robin fashion. A
1072 * batch_free count is maintained that is incremented when an
1073 * empty list is encountered. This is so more pages are freed
1074 * off fuller lists instead of spinning excessively around empty
1075 * lists
1076 */
1077 do {
1078 batch_free++;
1079 if (++migratetype == MIGRATE_PCPTYPES)
1080 migratetype = 0;
1081 list = &pcp->lists[migratetype];
1082 } while (list_empty(list));
1083
1084 /* This is the only non-empty list. Free them all. */
1085 if (batch_free == MIGRATE_PCPTYPES)
1086 batch_free = count;
1087
1088 do {
1089 int mt; /* migratetype of the to-be-freed page */
1090
1091 page = list_last_entry(list, struct page, lru);
1092 /* must delete as __free_one_page list manipulates */
1093 list_del(&page->lru);
1094
1095 mt = get_pcppage_migratetype(page);
1096 /* MIGRATE_ISOLATE page should not go to pcplists */
1097 VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
1098 /* Pageblock could have been isolated meanwhile */
1099 if (unlikely(isolated_pageblocks))
1100 mt = get_pageblock_migratetype(page);
1101
1102 if (bulkfree_pcp_prepare(page))
1103 continue;
1104
1105 __free_one_page(page, page_to_pfn(page), zone, 0, mt);
1106 trace_mm_page_pcpu_drain(page, 0, mt);
1107 } while (--count && --batch_free && !list_empty(list));
1108 }
1109 spin_unlock(&zone->lock);
1110 }
1111
1112 static void free_one_page(struct zone *zone,
1113 struct page *page, unsigned long pfn,
1114 unsigned int order,
1115 int migratetype)
1116 {
1117 unsigned long nr_scanned;
1118 spin_lock(&zone->lock);
1119 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
1120 if (nr_scanned)
1121 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
1122
1123 if (unlikely(has_isolate_pageblock(zone) ||
1124 is_migrate_isolate(migratetype))) {
1125 migratetype = get_pfnblock_migratetype(page, pfn);
1126 }
1127 __free_one_page(page, pfn, zone, order, migratetype);
1128 spin_unlock(&zone->lock);
1129 }
1130
1131 static void __meminit __init_single_page(struct page *page, unsigned long pfn,
1132 unsigned long zone, int nid)
1133 {
1134 set_page_links(page, zone, nid, pfn);
1135 init_page_count(page);
1136 page_mapcount_reset(page);
1137 page_cpupid_reset_last(page);
1138
1139 INIT_LIST_HEAD(&page->lru);
1140 #ifdef WANT_PAGE_VIRTUAL
1141 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1142 if (!is_highmem_idx(zone))
1143 set_page_address(page, __va(pfn << PAGE_SHIFT));
1144 #endif
1145 }
1146
1147 static void __meminit __init_single_pfn(unsigned long pfn, unsigned long zone,
1148 int nid)
1149 {
1150 return __init_single_page(pfn_to_page(pfn), pfn, zone, nid);
1151 }
1152
1153 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1154 static void init_reserved_page(unsigned long pfn)
1155 {
1156 pg_data_t *pgdat;
1157 int nid, zid;
1158
1159 if (!early_page_uninitialised(pfn))
1160 return;
1161
1162 nid = early_pfn_to_nid(pfn);
1163 pgdat = NODE_DATA(nid);
1164
1165 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1166 struct zone *zone = &pgdat->node_zones[zid];
1167
1168 if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone))
1169 break;
1170 }
1171 __init_single_pfn(pfn, zid, nid);
1172 }
1173 #else
1174 static inline void init_reserved_page(unsigned long pfn)
1175 {
1176 }
1177 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1178
1179 /*
1180 * Initialised pages do not have PageReserved set. This function is
1181 * called for each range allocated by the bootmem allocator and
1182 * marks the pages PageReserved. The remaining valid pages are later
1183 * sent to the buddy page allocator.
1184 */
1185 void __meminit reserve_bootmem_region(unsigned long start, unsigned long end)
1186 {
1187 unsigned long start_pfn = PFN_DOWN(start);
1188 unsigned long end_pfn = PFN_UP(end);
1189
1190 for (; start_pfn < end_pfn; start_pfn++) {
1191 if (pfn_valid(start_pfn)) {
1192 struct page *page = pfn_to_page(start_pfn);
1193
1194 init_reserved_page(start_pfn);
1195
1196 /* Avoid false-positive PageTail() */
1197 INIT_LIST_HEAD(&page->lru);
1198
1199 SetPageReserved(page);
1200 }
1201 }
1202 }
1203
1204 static bool free_pages_prepare(struct page *page, unsigned int order)
1205 {
1206 int bad = 0;
1207
1208 VM_BUG_ON_PAGE(PageTail(page), page);
1209
1210 trace_mm_page_free(page, order);
1211 kmemcheck_free_shadow(page, order);
1212 kasan_free_pages(page, order);
1213
1214 /*
1215 * Check tail pages before head page information is cleared to
1216 * avoid checking PageCompound for order-0 pages.
1217 */
1218 if (unlikely(order)) {
1219 bool compound = PageCompound(page);
1220 int i;
1221
1222 VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
1223
1224 for (i = 1; i < (1 << order); i++) {
1225 if (compound)
1226 bad += free_tail_pages_check(page, page + i);
1227 if (unlikely(free_pages_check(page + i))) {
1228 bad++;
1229 continue;
1230 }
1231 (page + i)->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1232 }
1233 }
1234 if (PageAnonHead(page))
1235 page->mapping = NULL;
1236 bad += free_pages_check(page);
1237 if (bad)
1238 return false;
1239
1240 page_cpupid_reset_last(page);
1241 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
1242 reset_page_owner(page, order);
1243
1244 if (!PageHighMem(page)) {
1245 debug_check_no_locks_freed(page_address(page),
1246 PAGE_SIZE << order);
1247 debug_check_no_obj_freed(page_address(page),
1248 PAGE_SIZE << order);
1249 }
1250 arch_free_page(page, order);
1251 kernel_poison_pages(page, 1 << order, 0);
1252 kernel_map_pages(page, 1 << order, 0);
1253
1254 return true;
1255 }
1256
1257 static void __free_pages_ok(struct page *page, unsigned int order)
1258 {
1259 unsigned long flags;
1260 int migratetype;
1261 unsigned long pfn = page_to_pfn(page);
1262
1263 if (!free_pages_prepare(page, order))
1264 return;
1265
1266 migratetype = get_pfnblock_migratetype(page, pfn);
1267 local_irq_save(flags);
1268 __count_vm_events(PGFREE, 1 << order);
1269 free_one_page(page_zone(page), page, pfn, order, migratetype);
1270 local_irq_restore(flags);
1271 }
1272
1273 static void __init __free_pages_boot_core(struct page *page, unsigned int order)
1274 {
1275 unsigned int nr_pages = 1 << order;
1276 struct page *p = page;
1277 unsigned int loop;
1278
1279 prefetchw(p);
1280 for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
1281 prefetchw(p + 1);
1282 __ClearPageReserved(p);
1283 set_page_count(p, 0);
1284 }
1285 __ClearPageReserved(p);
1286 set_page_count(p, 0);
1287
1288 page_zone(page)->managed_pages += nr_pages;
1289 set_page_refcounted(page);
1290 __free_pages(page, order);
1291 }
1292
1293 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1294 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1295
1296 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
1297
1298 int __meminit early_pfn_to_nid(unsigned long pfn)
1299 {
1300 static DEFINE_SPINLOCK(early_pfn_lock);
1301 int nid;
1302
1303 spin_lock(&early_pfn_lock);
1304 nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache);
1305 if (nid < 0)
1306 nid = 0;
1307 spin_unlock(&early_pfn_lock);
1308
1309 return nid;
1310 }
1311 #endif
1312
1313 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1314 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
1315 struct mminit_pfnnid_cache *state)
1316 {
1317 int nid;
1318
1319 nid = __early_pfn_to_nid(pfn, state);
1320 if (nid >= 0 && nid != node)
1321 return false;
1322 return true;
1323 }
1324
1325 /* Only safe to use early in boot when initialisation is single-threaded */
1326 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1327 {
1328 return meminit_pfn_in_nid(pfn, node, &early_pfnnid_cache);
1329 }
1330
1331 #else
1332
1333 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
1334 {
1335 return true;
1336 }
1337 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
1338 struct mminit_pfnnid_cache *state)
1339 {
1340 return true;
1341 }
1342 #endif
1343
1344
1345 void __init __free_pages_bootmem(struct page *page, unsigned long pfn,
1346 unsigned int order)
1347 {
1348 if (early_page_uninitialised(pfn))
1349 return;
1350 return __free_pages_boot_core(page, order);
1351 }
1352
1353 /*
1354 * Check that the whole (or subset of) a pageblock given by the interval of
1355 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1356 * with the migration of free compaction scanner. The scanners then need to
1357 * use only pfn_valid_within() check for arches that allow holes within
1358 * pageblocks.
1359 *
1360 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1361 *
1362 * It's possible on some configurations to have a setup like node0 node1 node0
1363 * i.e. it's possible that all pages within a zones range of pages do not
1364 * belong to a single zone. We assume that a border between node0 and node1
1365 * can occur within a single pageblock, but not a node0 node1 node0
1366 * interleaving within a single pageblock. It is therefore sufficient to check
1367 * the first and last page of a pageblock and avoid checking each individual
1368 * page in a pageblock.
1369 */
1370 struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
1371 unsigned long end_pfn, struct zone *zone)
1372 {
1373 struct page *start_page;
1374 struct page *end_page;
1375
1376 /* end_pfn is one past the range we are checking */
1377 end_pfn--;
1378
1379 if (!pfn_valid(start_pfn) || !pfn_valid(end_pfn))
1380 return NULL;
1381
1382 start_page = pfn_to_page(start_pfn);
1383
1384 if (page_zone(start_page) != zone)
1385 return NULL;
1386
1387 end_page = pfn_to_page(end_pfn);
1388
1389 /* This gives a shorter code than deriving page_zone(end_page) */
1390 if (page_zone_id(start_page) != page_zone_id(end_page))
1391 return NULL;
1392
1393 return start_page;
1394 }
1395
1396 void set_zone_contiguous(struct zone *zone)
1397 {
1398 unsigned long block_start_pfn = zone->zone_start_pfn;
1399 unsigned long block_end_pfn;
1400
1401 block_end_pfn = ALIGN(block_start_pfn + 1, pageblock_nr_pages);
1402 for (; block_start_pfn < zone_end_pfn(zone);
1403 block_start_pfn = block_end_pfn,
1404 block_end_pfn += pageblock_nr_pages) {
1405
1406 block_end_pfn = min(block_end_pfn, zone_end_pfn(zone));
1407
1408 if (!__pageblock_pfn_to_page(block_start_pfn,
1409 block_end_pfn, zone))
1410 return;
1411 }
1412
1413 /* We confirm that there is no hole */
1414 zone->contiguous = true;
1415 }
1416
1417 void clear_zone_contiguous(struct zone *zone)
1418 {
1419 zone->contiguous = false;
1420 }
1421
1422 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1423 static void __init deferred_free_range(struct page *page,
1424 unsigned long pfn, int nr_pages)
1425 {
1426 int i;
1427
1428 if (!page)
1429 return;
1430
1431 /* Free a large naturally-aligned chunk if possible */
1432 if (nr_pages == MAX_ORDER_NR_PAGES &&
1433 (pfn & (MAX_ORDER_NR_PAGES-1)) == 0) {
1434 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
1435 __free_pages_boot_core(page, MAX_ORDER-1);
1436 return;
1437 }
1438
1439 for (i = 0; i < nr_pages; i++, page++)
1440 __free_pages_boot_core(page, 0);
1441 }
1442
1443 /* Completion tracking for deferred_init_memmap() threads */
1444 static atomic_t pgdat_init_n_undone __initdata;
1445 static __initdata DECLARE_COMPLETION(pgdat_init_all_done_comp);
1446
1447 static inline void __init pgdat_init_report_one_done(void)
1448 {
1449 if (atomic_dec_and_test(&pgdat_init_n_undone))
1450 complete(&pgdat_init_all_done_comp);
1451 }
1452
1453 /* Initialise remaining memory on a node */
1454 static int __init deferred_init_memmap(void *data)
1455 {
1456 pg_data_t *pgdat = data;
1457 int nid = pgdat->node_id;
1458 struct mminit_pfnnid_cache nid_init_state = { };
1459 unsigned long start = jiffies;
1460 unsigned long nr_pages = 0;
1461 unsigned long walk_start, walk_end;
1462 int i, zid;
1463 struct zone *zone;
1464 unsigned long first_init_pfn = pgdat->first_deferred_pfn;
1465 const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
1466
1467 if (first_init_pfn == ULONG_MAX) {
1468 pgdat_init_report_one_done();
1469 return 0;
1470 }
1471
1472 /* Bind memory initialisation thread to a local node if possible */
1473 if (!cpumask_empty(cpumask))
1474 set_cpus_allowed_ptr(current, cpumask);
1475
1476 /* Sanity check boundaries */
1477 BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn);
1478 BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat));
1479 pgdat->first_deferred_pfn = ULONG_MAX;
1480
1481 /* Only the highest zone is deferred so find it */
1482 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1483 zone = pgdat->node_zones + zid;
1484 if (first_init_pfn < zone_end_pfn(zone))
1485 break;
1486 }
1487
1488 for_each_mem_pfn_range(i, nid, &walk_start, &walk_end, NULL) {
1489 unsigned long pfn, end_pfn;
1490 struct page *page = NULL;
1491 struct page *free_base_page = NULL;
1492 unsigned long free_base_pfn = 0;
1493 int nr_to_free = 0;
1494
1495 end_pfn = min(walk_end, zone_end_pfn(zone));
1496 pfn = first_init_pfn;
1497 if (pfn < walk_start)
1498 pfn = walk_start;
1499 if (pfn < zone->zone_start_pfn)
1500 pfn = zone->zone_start_pfn;
1501
1502 for (; pfn < end_pfn; pfn++) {
1503 if (!pfn_valid_within(pfn))
1504 goto free_range;
1505
1506 /*
1507 * Ensure pfn_valid is checked every
1508 * MAX_ORDER_NR_PAGES for memory holes
1509 */
1510 if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0) {
1511 if (!pfn_valid(pfn)) {
1512 page = NULL;
1513 goto free_range;
1514 }
1515 }
1516
1517 if (!meminit_pfn_in_nid(pfn, nid, &nid_init_state)) {
1518 page = NULL;
1519 goto free_range;
1520 }
1521
1522 /* Minimise pfn page lookups and scheduler checks */
1523 if (page && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0) {
1524 page++;
1525 } else {
1526 nr_pages += nr_to_free;
1527 deferred_free_range(free_base_page,
1528 free_base_pfn, nr_to_free);
1529 free_base_page = NULL;
1530 free_base_pfn = nr_to_free = 0;
1531
1532 page = pfn_to_page(pfn);
1533 cond_resched();
1534 }
1535
1536 if (page->flags) {
1537 VM_BUG_ON(page_zone(page) != zone);
1538 goto free_range;
1539 }
1540
1541 __init_single_page(page, pfn, zid, nid);
1542 if (!free_base_page) {
1543 free_base_page = page;
1544 free_base_pfn = pfn;
1545 nr_to_free = 0;
1546 }
1547 nr_to_free++;
1548
1549 /* Where possible, batch up pages for a single free */
1550 continue;
1551 free_range:
1552 /* Free the current block of pages to allocator */
1553 nr_pages += nr_to_free;
1554 deferred_free_range(free_base_page, free_base_pfn,
1555 nr_to_free);
1556 free_base_page = NULL;
1557 free_base_pfn = nr_to_free = 0;
1558 }
1559
1560 first_init_pfn = max(end_pfn, first_init_pfn);
1561 }
1562
1563 /* Sanity check that the next zone really is unpopulated */
1564 WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone));
1565
1566 pr_info("node %d initialised, %lu pages in %ums\n", nid, nr_pages,
1567 jiffies_to_msecs(jiffies - start));
1568
1569 pgdat_init_report_one_done();
1570 return 0;
1571 }
1572 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1573
1574 void __init page_alloc_init_late(void)
1575 {
1576 struct zone *zone;
1577
1578 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1579 int nid;
1580
1581 /* There will be num_node_state(N_MEMORY) threads */
1582 atomic_set(&pgdat_init_n_undone, num_node_state(N_MEMORY));
1583 for_each_node_state(nid, N_MEMORY) {
1584 kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid);
1585 }
1586
1587 /* Block until all are initialised */
1588 wait_for_completion(&pgdat_init_all_done_comp);
1589
1590 /* Reinit limits that are based on free pages after the kernel is up */
1591 files_maxfiles_init();
1592 #endif
1593
1594 for_each_populated_zone(zone)
1595 set_zone_contiguous(zone);
1596 }
1597
1598 #ifdef CONFIG_CMA
1599 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1600 void __init init_cma_reserved_pageblock(struct page *page)
1601 {
1602 unsigned i = pageblock_nr_pages;
1603 struct page *p = page;
1604
1605 do {
1606 __ClearPageReserved(p);
1607 set_page_count(p, 0);
1608 } while (++p, --i);
1609
1610 set_pageblock_migratetype(page, MIGRATE_CMA);
1611
1612 if (pageblock_order >= MAX_ORDER) {
1613 i = pageblock_nr_pages;
1614 p = page;
1615 do {
1616 set_page_refcounted(p);
1617 __free_pages(p, MAX_ORDER - 1);
1618 p += MAX_ORDER_NR_PAGES;
1619 } while (i -= MAX_ORDER_NR_PAGES);
1620 } else {
1621 set_page_refcounted(page);
1622 __free_pages(page, pageblock_order);
1623 }
1624
1625 adjust_managed_page_count(page, pageblock_nr_pages);
1626 }
1627 #endif
1628
1629 /*
1630 * The order of subdivision here is critical for the IO subsystem.
1631 * Please do not alter this order without good reasons and regression
1632 * testing. Specifically, as large blocks of memory are subdivided,
1633 * the order in which smaller blocks are delivered depends on the order
1634 * they're subdivided in this function. This is the primary factor
1635 * influencing the order in which pages are delivered to the IO
1636 * subsystem according to empirical testing, and this is also justified
1637 * by considering the behavior of a buddy system containing a single
1638 * large block of memory acted on by a series of small allocations.
1639 * This behavior is a critical factor in sglist merging's success.
1640 *
1641 * -- nyc
1642 */
1643 static inline void expand(struct zone *zone, struct page *page,
1644 int low, int high, struct free_area *area,
1645 int migratetype)
1646 {
1647 unsigned long size = 1 << high;
1648
1649 while (high > low) {
1650 area--;
1651 high--;
1652 size >>= 1;
1653 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
1654
1655 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) &&
1656 debug_guardpage_enabled() &&
1657 high < debug_guardpage_minorder()) {
1658 /*
1659 * Mark as guard pages (or page), that will allow to
1660 * merge back to allocator when buddy will be freed.
1661 * Corresponding page table entries will not be touched,
1662 * pages will stay not present in virtual address space
1663 */
1664 set_page_guard(zone, &page[size], high, migratetype);
1665 continue;
1666 }
1667 list_add(&page[size].lru, &area->free_list[migratetype]);
1668 area->nr_free++;
1669 set_page_order(&page[size], high);
1670 }
1671 }
1672
1673 /*
1674 * This page is about to be returned from the page allocator
1675 */
1676 static inline int check_new_page(struct page *page)
1677 {
1678 const char *bad_reason;
1679 unsigned long bad_flags;
1680
1681 if (page_expected_state(page, PAGE_FLAGS_CHECK_AT_PREP|__PG_HWPOISON))
1682 return 0;
1683
1684 bad_reason = NULL;
1685 bad_flags = 0;
1686 if (unlikely(atomic_read(&page->_mapcount) != -1))
1687 bad_reason = "nonzero mapcount";
1688 if (unlikely(page->mapping != NULL))
1689 bad_reason = "non-NULL mapping";
1690 if (unlikely(page_ref_count(page) != 0))
1691 bad_reason = "nonzero _count";
1692 if (unlikely(page->flags & __PG_HWPOISON)) {
1693 bad_reason = "HWPoisoned (hardware-corrupted)";
1694 bad_flags = __PG_HWPOISON;
1695 }
1696 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
1697 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
1698 bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
1699 }
1700 #ifdef CONFIG_MEMCG
1701 if (unlikely(page->mem_cgroup))
1702 bad_reason = "page still charged to cgroup";
1703 #endif
1704 if (unlikely(bad_reason)) {
1705 bad_page(page, bad_reason, bad_flags);
1706 return 1;
1707 }
1708 return 0;
1709 }
1710
1711 static inline bool free_pages_prezeroed(bool poisoned)
1712 {
1713 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) &&
1714 page_poisoning_enabled() && poisoned;
1715 }
1716
1717 static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
1718 unsigned int alloc_flags)
1719 {
1720 int i;
1721 bool poisoned = true;
1722
1723 for (i = 0; i < (1 << order); i++) {
1724 struct page *p = page + i;
1725 if (unlikely(check_new_page(p)))
1726 return 1;
1727 if (poisoned)
1728 poisoned &= page_is_poisoned(p);
1729 }
1730
1731 set_page_private(page, 0);
1732 set_page_refcounted(page);
1733
1734 arch_alloc_page(page, order);
1735 kernel_map_pages(page, 1 << order, 1);
1736 kernel_poison_pages(page, 1 << order, 1);
1737 kasan_alloc_pages(page, order);
1738
1739 if (!free_pages_prezeroed(poisoned) && (gfp_flags & __GFP_ZERO))
1740 for (i = 0; i < (1 << order); i++)
1741 clear_highpage(page + i);
1742
1743 if (order && (gfp_flags & __GFP_COMP))
1744 prep_compound_page(page, order);
1745
1746 set_page_owner(page, order, gfp_flags);
1747
1748 /*
1749 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1750 * allocate the page. The expectation is that the caller is taking
1751 * steps that will free more memory. The caller should avoid the page
1752 * being used for !PFMEMALLOC purposes.
1753 */
1754 if (alloc_flags & ALLOC_NO_WATERMARKS)
1755 set_page_pfmemalloc(page);
1756 else
1757 clear_page_pfmemalloc(page);
1758
1759 return 0;
1760 }
1761
1762 /*
1763 * Go through the free lists for the given migratetype and remove
1764 * the smallest available page from the freelists
1765 */
1766 static inline
1767 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
1768 int migratetype)
1769 {
1770 unsigned int current_order;
1771 struct free_area *area;
1772 struct page *page;
1773
1774 /* Find a page of the appropriate size in the preferred list */
1775 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
1776 area = &(zone->free_area[current_order]);
1777 page = list_first_entry_or_null(&area->free_list[migratetype],
1778 struct page, lru);
1779 if (!page)
1780 continue;
1781 list_del(&page->lru);
1782 rmv_page_order(page);
1783 area->nr_free--;
1784 expand(zone, page, order, current_order, area, migratetype);
1785 set_pcppage_migratetype(page, migratetype);
1786 return page;
1787 }
1788
1789 return NULL;
1790 }
1791
1792
1793 /*
1794 * This array describes the order lists are fallen back to when
1795 * the free lists for the desirable migrate type are depleted
1796 */
1797 static int fallbacks[MIGRATE_TYPES][4] = {
1798 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
1799 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
1800 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES },
1801 #ifdef CONFIG_CMA
1802 [MIGRATE_CMA] = { MIGRATE_TYPES }, /* Never used */
1803 #endif
1804 #ifdef CONFIG_MEMORY_ISOLATION
1805 [MIGRATE_ISOLATE] = { MIGRATE_TYPES }, /* Never used */
1806 #endif
1807 };
1808
1809 #ifdef CONFIG_CMA
1810 static struct page *__rmqueue_cma_fallback(struct zone *zone,
1811 unsigned int order)
1812 {
1813 return __rmqueue_smallest(zone, order, MIGRATE_CMA);
1814 }
1815 #else
1816 static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
1817 unsigned int order) { return NULL; }
1818 #endif
1819
1820 /*
1821 * Move the free pages in a range to the free lists of the requested type.
1822 * Note that start_page and end_pages are not aligned on a pageblock
1823 * boundary. If alignment is required, use move_freepages_block()
1824 */
1825 int move_freepages(struct zone *zone,
1826 struct page *start_page, struct page *end_page,
1827 int migratetype)
1828 {
1829 struct page *page;
1830 unsigned int order;
1831 int pages_moved = 0;
1832
1833 #ifndef CONFIG_HOLES_IN_ZONE
1834 /*
1835 * page_zone is not safe to call in this context when
1836 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1837 * anyway as we check zone boundaries in move_freepages_block().
1838 * Remove at a later date when no bug reports exist related to
1839 * grouping pages by mobility
1840 */
1841 VM_BUG_ON(page_zone(start_page) != page_zone(end_page));
1842 #endif
1843
1844 for (page = start_page; page <= end_page;) {
1845 /* Make sure we are not inadvertently changing nodes */
1846 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
1847
1848 if (!pfn_valid_within(page_to_pfn(page))) {
1849 page++;
1850 continue;
1851 }
1852
1853 if (!PageBuddy(page)) {
1854 page++;
1855 continue;
1856 }
1857
1858 order = page_order(page);
1859 list_move(&page->lru,
1860 &zone->free_area[order].free_list[migratetype]);
1861 page += 1 << order;
1862 pages_moved += 1 << order;
1863 }
1864
1865 return pages_moved;
1866 }
1867
1868 int move_freepages_block(struct zone *zone, struct page *page,
1869 int migratetype)
1870 {
1871 unsigned long start_pfn, end_pfn;
1872 struct page *start_page, *end_page;
1873
1874 start_pfn = page_to_pfn(page);
1875 start_pfn = start_pfn & ~(pageblock_nr_pages-1);
1876 start_page = pfn_to_page(start_pfn);
1877 end_page = start_page + pageblock_nr_pages - 1;
1878 end_pfn = start_pfn + pageblock_nr_pages - 1;
1879
1880 /* Do not cross zone boundaries */
1881 if (!zone_spans_pfn(zone, start_pfn))
1882 start_page = page;
1883 if (!zone_spans_pfn(zone, end_pfn))
1884 return 0;
1885
1886 return move_freepages(zone, start_page, end_page, migratetype);
1887 }
1888
1889 static void change_pageblock_range(struct page *pageblock_page,
1890 int start_order, int migratetype)
1891 {
1892 int nr_pageblocks = 1 << (start_order - pageblock_order);
1893
1894 while (nr_pageblocks--) {
1895 set_pageblock_migratetype(pageblock_page, migratetype);
1896 pageblock_page += pageblock_nr_pages;
1897 }
1898 }
1899
1900 /*
1901 * When we are falling back to another migratetype during allocation, try to
1902 * steal extra free pages from the same pageblocks to satisfy further
1903 * allocations, instead of polluting multiple pageblocks.
1904 *
1905 * If we are stealing a relatively large buddy page, it is likely there will
1906 * be more free pages in the pageblock, so try to steal them all. For
1907 * reclaimable and unmovable allocations, we steal regardless of page size,
1908 * as fragmentation caused by those allocations polluting movable pageblocks
1909 * is worse than movable allocations stealing from unmovable and reclaimable
1910 * pageblocks.
1911 */
1912 static bool can_steal_fallback(unsigned int order, int start_mt)
1913 {
1914 /*
1915 * Leaving this order check is intended, although there is
1916 * relaxed order check in next check. The reason is that
1917 * we can actually steal whole pageblock if this condition met,
1918 * but, below check doesn't guarantee it and that is just heuristic
1919 * so could be changed anytime.
1920 */
1921 if (order >= pageblock_order)
1922 return true;
1923
1924 if (order >= pageblock_order / 2 ||
1925 start_mt == MIGRATE_RECLAIMABLE ||
1926 start_mt == MIGRATE_UNMOVABLE ||
1927 page_group_by_mobility_disabled)
1928 return true;
1929
1930 return false;
1931 }
1932
1933 /*
1934 * This function implements actual steal behaviour. If order is large enough,
1935 * we can steal whole pageblock. If not, we first move freepages in this
1936 * pageblock and check whether half of pages are moved or not. If half of
1937 * pages are moved, we can change migratetype of pageblock and permanently
1938 * use it's pages as requested migratetype in the future.
1939 */
1940 static void steal_suitable_fallback(struct zone *zone, struct page *page,
1941 int start_type)
1942 {
1943 unsigned int current_order = page_order(page);
1944 int pages;
1945
1946 /* Take ownership for orders >= pageblock_order */
1947 if (current_order >= pageblock_order) {
1948 change_pageblock_range(page, current_order, start_type);
1949 return;
1950 }
1951
1952 pages = move_freepages_block(zone, page, start_type);
1953
1954 /* Claim the whole block if over half of it is free */
1955 if (pages >= (1 << (pageblock_order-1)) ||
1956 page_group_by_mobility_disabled)
1957 set_pageblock_migratetype(page, start_type);
1958 }
1959
1960 /*
1961 * Check whether there is a suitable fallback freepage with requested order.
1962 * If only_stealable is true, this function returns fallback_mt only if
1963 * we can steal other freepages all together. This would help to reduce
1964 * fragmentation due to mixed migratetype pages in one pageblock.
1965 */
1966 int find_suitable_fallback(struct free_area *area, unsigned int order,
1967 int migratetype, bool only_stealable, bool *can_steal)
1968 {
1969 int i;
1970 int fallback_mt;
1971
1972 if (area->nr_free == 0)
1973 return -1;
1974
1975 *can_steal = false;
1976 for (i = 0;; i++) {
1977 fallback_mt = fallbacks[migratetype][i];
1978 if (fallback_mt == MIGRATE_TYPES)
1979 break;
1980
1981 if (list_empty(&area->free_list[fallback_mt]))
1982 continue;
1983
1984 if (can_steal_fallback(order, migratetype))
1985 *can_steal = true;
1986
1987 if (!only_stealable)
1988 return fallback_mt;
1989
1990 if (*can_steal)
1991 return fallback_mt;
1992 }
1993
1994 return -1;
1995 }
1996
1997 /*
1998 * Reserve a pageblock for exclusive use of high-order atomic allocations if
1999 * there are no empty page blocks that contain a page with a suitable order
2000 */
2001 static void reserve_highatomic_pageblock(struct page *page, struct zone *zone,
2002 unsigned int alloc_order)
2003 {
2004 int mt;
2005 unsigned long max_managed, flags;
2006
2007 /*
2008 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2009 * Check is race-prone but harmless.
2010 */
2011 max_managed = (zone->managed_pages / 100) + pageblock_nr_pages;
2012 if (zone->nr_reserved_highatomic >= max_managed)
2013 return;
2014
2015 spin_lock_irqsave(&zone->lock, flags);
2016
2017 /* Recheck the nr_reserved_highatomic limit under the lock */
2018 if (zone->nr_reserved_highatomic >= max_managed)
2019 goto out_unlock;
2020
2021 /* Yoink! */
2022 mt = get_pageblock_migratetype(page);
2023 if (mt != MIGRATE_HIGHATOMIC &&
2024 !is_migrate_isolate(mt) && !is_migrate_cma(mt)) {
2025 zone->nr_reserved_highatomic += pageblock_nr_pages;
2026 set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC);
2027 move_freepages_block(zone, page, MIGRATE_HIGHATOMIC);
2028 }
2029
2030 out_unlock:
2031 spin_unlock_irqrestore(&zone->lock, flags);
2032 }
2033
2034 /*
2035 * Used when an allocation is about to fail under memory pressure. This
2036 * potentially hurts the reliability of high-order allocations when under
2037 * intense memory pressure but failed atomic allocations should be easier
2038 * to recover from than an OOM.
2039 */
2040 static void unreserve_highatomic_pageblock(const struct alloc_context *ac)
2041 {
2042 struct zonelist *zonelist = ac->zonelist;
2043 unsigned long flags;
2044 struct zoneref *z;
2045 struct zone *zone;
2046 struct page *page;
2047 int order;
2048
2049 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx,
2050 ac->nodemask) {
2051 /* Preserve at least one pageblock */
2052 if (zone->nr_reserved_highatomic <= pageblock_nr_pages)
2053 continue;
2054
2055 spin_lock_irqsave(&zone->lock, flags);
2056 for (order = 0; order < MAX_ORDER; order++) {
2057 struct free_area *area = &(zone->free_area[order]);
2058
2059 page = list_first_entry_or_null(
2060 &area->free_list[MIGRATE_HIGHATOMIC],
2061 struct page, lru);
2062 if (!page)
2063 continue;
2064
2065 /*
2066 * It should never happen but changes to locking could
2067 * inadvertently allow a per-cpu drain to add pages
2068 * to MIGRATE_HIGHATOMIC while unreserving so be safe
2069 * and watch for underflows.
2070 */
2071 zone->nr_reserved_highatomic -= min(pageblock_nr_pages,
2072 zone->nr_reserved_highatomic);
2073
2074 /*
2075 * Convert to ac->migratetype and avoid the normal
2076 * pageblock stealing heuristics. Minimally, the caller
2077 * is doing the work and needs the pages. More
2078 * importantly, if the block was always converted to
2079 * MIGRATE_UNMOVABLE or another type then the number
2080 * of pageblocks that cannot be completely freed
2081 * may increase.
2082 */
2083 set_pageblock_migratetype(page, ac->migratetype);
2084 move_freepages_block(zone, page, ac->migratetype);
2085 spin_unlock_irqrestore(&zone->lock, flags);
2086 return;
2087 }
2088 spin_unlock_irqrestore(&zone->lock, flags);
2089 }
2090 }
2091
2092 /* Remove an element from the buddy allocator from the fallback list */
2093 static inline struct page *
2094 __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
2095 {
2096 struct free_area *area;
2097 unsigned int current_order;
2098 struct page *page;
2099 int fallback_mt;
2100 bool can_steal;
2101
2102 /* Find the largest possible block of pages in the other list */
2103 for (current_order = MAX_ORDER-1;
2104 current_order >= order && current_order <= MAX_ORDER-1;
2105 --current_order) {
2106 area = &(zone->free_area[current_order]);
2107 fallback_mt = find_suitable_fallback(area, current_order,
2108 start_migratetype, false, &can_steal);
2109 if (fallback_mt == -1)
2110 continue;
2111
2112 page = list_first_entry(&area->free_list[fallback_mt],
2113 struct page, lru);
2114 if (can_steal)
2115 steal_suitable_fallback(zone, page, start_migratetype);
2116
2117 /* Remove the page from the freelists */
2118 area->nr_free--;
2119 list_del(&page->lru);
2120 rmv_page_order(page);
2121
2122 expand(zone, page, order, current_order, area,
2123 start_migratetype);
2124 /*
2125 * The pcppage_migratetype may differ from pageblock's
2126 * migratetype depending on the decisions in
2127 * find_suitable_fallback(). This is OK as long as it does not
2128 * differ for MIGRATE_CMA pageblocks. Those can be used as
2129 * fallback only via special __rmqueue_cma_fallback() function
2130 */
2131 set_pcppage_migratetype(page, start_migratetype);
2132
2133 trace_mm_page_alloc_extfrag(page, order, current_order,
2134 start_migratetype, fallback_mt);
2135
2136 return page;
2137 }
2138
2139 return NULL;
2140 }
2141
2142 /*
2143 * Do the hard work of removing an element from the buddy allocator.
2144 * Call me with the zone->lock already held.
2145 */
2146 static struct page *__rmqueue(struct zone *zone, unsigned int order,
2147 int migratetype)
2148 {
2149 struct page *page;
2150
2151 page = __rmqueue_smallest(zone, order, migratetype);
2152 if (unlikely(!page)) {
2153 if (migratetype == MIGRATE_MOVABLE)
2154 page = __rmqueue_cma_fallback(zone, order);
2155
2156 if (!page)
2157 page = __rmqueue_fallback(zone, order, migratetype);
2158 }
2159
2160 trace_mm_page_alloc_zone_locked(page, order, migratetype);
2161 return page;
2162 }
2163
2164 /*
2165 * Obtain a specified number of elements from the buddy allocator, all under
2166 * a single hold of the lock, for efficiency. Add them to the supplied list.
2167 * Returns the number of new pages which were placed at *list.
2168 */
2169 static int rmqueue_bulk(struct zone *zone, unsigned int order,
2170 unsigned long count, struct list_head *list,
2171 int migratetype, bool cold)
2172 {
2173 int i;
2174
2175 spin_lock(&zone->lock);
2176 for (i = 0; i < count; ++i) {
2177 struct page *page = __rmqueue(zone, order, migratetype);
2178 if (unlikely(page == NULL))
2179 break;
2180
2181 /*
2182 * Split buddy pages returned by expand() are received here
2183 * in physical page order. The page is added to the callers and
2184 * list and the list head then moves forward. From the callers
2185 * perspective, the linked list is ordered by page number in
2186 * some conditions. This is useful for IO devices that can
2187 * merge IO requests if the physical pages are ordered
2188 * properly.
2189 */
2190 if (likely(!cold))
2191 list_add(&page->lru, list);
2192 else
2193 list_add_tail(&page->lru, list);
2194 list = &page->lru;
2195 if (is_migrate_cma(get_pcppage_migratetype(page)))
2196 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
2197 -(1 << order));
2198 }
2199 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
2200 spin_unlock(&zone->lock);
2201 return i;
2202 }
2203
2204 #ifdef CONFIG_NUMA
2205 /*
2206 * Called from the vmstat counter updater to drain pagesets of this
2207 * currently executing processor on remote nodes after they have
2208 * expired.
2209 *
2210 * Note that this function must be called with the thread pinned to
2211 * a single processor.
2212 */
2213 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
2214 {
2215 unsigned long flags;
2216 int to_drain, batch;
2217
2218 local_irq_save(flags);
2219 batch = READ_ONCE(pcp->batch);
2220 to_drain = min(pcp->count, batch);
2221 if (to_drain > 0) {
2222 free_pcppages_bulk(zone, to_drain, pcp);
2223 pcp->count -= to_drain;
2224 }
2225 local_irq_restore(flags);
2226 }
2227 #endif
2228
2229 /*
2230 * Drain pcplists of the indicated processor and zone.
2231 *
2232 * The processor must either be the current processor and the
2233 * thread pinned to the current processor or a processor that
2234 * is not online.
2235 */
2236 static void drain_pages_zone(unsigned int cpu, struct zone *zone)
2237 {
2238 unsigned long flags;
2239 struct per_cpu_pageset *pset;
2240 struct per_cpu_pages *pcp;
2241
2242 local_irq_save(flags);
2243 pset = per_cpu_ptr(zone->pageset, cpu);
2244
2245 pcp = &pset->pcp;
2246 if (pcp->count) {
2247 free_pcppages_bulk(zone, pcp->count, pcp);
2248 pcp->count = 0;
2249 }
2250 local_irq_restore(flags);
2251 }
2252
2253 /*
2254 * Drain pcplists of all zones on the indicated processor.
2255 *
2256 * The processor must either be the current processor and the
2257 * thread pinned to the current processor or a processor that
2258 * is not online.
2259 */
2260 static void drain_pages(unsigned int cpu)
2261 {
2262 struct zone *zone;
2263
2264 for_each_populated_zone(zone) {
2265 drain_pages_zone(cpu, zone);
2266 }
2267 }
2268
2269 /*
2270 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2271 *
2272 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2273 * the single zone's pages.
2274 */
2275 void drain_local_pages(struct zone *zone)
2276 {
2277 int cpu = smp_processor_id();
2278
2279 if (zone)
2280 drain_pages_zone(cpu, zone);
2281 else
2282 drain_pages(cpu);
2283 }
2284
2285 /*
2286 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2287 *
2288 * When zone parameter is non-NULL, spill just the single zone's pages.
2289 *
2290 * Note that this code is protected against sending an IPI to an offline
2291 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
2292 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
2293 * nothing keeps CPUs from showing up after we populated the cpumask and
2294 * before the call to on_each_cpu_mask().
2295 */
2296 void drain_all_pages(struct zone *zone)
2297 {
2298 int cpu;
2299
2300 /*
2301 * Allocate in the BSS so we wont require allocation in
2302 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2303 */
2304 static cpumask_t cpus_with_pcps;
2305
2306 /*
2307 * We don't care about racing with CPU hotplug event
2308 * as offline notification will cause the notified
2309 * cpu to drain that CPU pcps and on_each_cpu_mask
2310 * disables preemption as part of its processing
2311 */
2312 for_each_online_cpu(cpu) {
2313 struct per_cpu_pageset *pcp;
2314 struct zone *z;
2315 bool has_pcps = false;
2316
2317 if (zone) {
2318 pcp = per_cpu_ptr(zone->pageset, cpu);
2319 if (pcp->pcp.count)
2320 has_pcps = true;
2321 } else {
2322 for_each_populated_zone(z) {
2323 pcp = per_cpu_ptr(z->pageset, cpu);
2324 if (pcp->pcp.count) {
2325 has_pcps = true;
2326 break;
2327 }
2328 }
2329 }
2330
2331 if (has_pcps)
2332 cpumask_set_cpu(cpu, &cpus_with_pcps);
2333 else
2334 cpumask_clear_cpu(cpu, &cpus_with_pcps);
2335 }
2336 on_each_cpu_mask(&cpus_with_pcps, (smp_call_func_t) drain_local_pages,
2337 zone, 1);
2338 }
2339
2340 #ifdef CONFIG_HIBERNATION
2341
2342 void mark_free_pages(struct zone *zone)
2343 {
2344 unsigned long pfn, max_zone_pfn;
2345 unsigned long flags;
2346 unsigned int order, t;
2347 struct page *page;
2348
2349 if (zone_is_empty(zone))
2350 return;
2351
2352 spin_lock_irqsave(&zone->lock, flags);
2353
2354 max_zone_pfn = zone_end_pfn(zone);
2355 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
2356 if (pfn_valid(pfn)) {
2357 page = pfn_to_page(pfn);
2358
2359 if (page_zone(page) != zone)
2360 continue;
2361
2362 if (!swsusp_page_is_forbidden(page))
2363 swsusp_unset_page_free(page);
2364 }
2365
2366 for_each_migratetype_order(order, t) {
2367 list_for_each_entry(page,
2368 &zone->free_area[order].free_list[t], lru) {
2369 unsigned long i;
2370
2371 pfn = page_to_pfn(page);
2372 for (i = 0; i < (1UL << order); i++)
2373 swsusp_set_page_free(pfn_to_page(pfn + i));
2374 }
2375 }
2376 spin_unlock_irqrestore(&zone->lock, flags);
2377 }
2378 #endif /* CONFIG_PM */
2379
2380 /*
2381 * Free a 0-order page
2382 * cold == true ? free a cold page : free a hot page
2383 */
2384 void free_hot_cold_page(struct page *page, bool cold)
2385 {
2386 struct zone *zone = page_zone(page);
2387 struct per_cpu_pages *pcp;
2388 unsigned long flags;
2389 unsigned long pfn = page_to_pfn(page);
2390 int migratetype;
2391
2392 if (!free_pcp_prepare(page))
2393 return;
2394
2395 migratetype = get_pfnblock_migratetype(page, pfn);
2396 set_pcppage_migratetype(page, migratetype);
2397 local_irq_save(flags);
2398 __count_vm_event(PGFREE);
2399
2400 /*
2401 * We only track unmovable, reclaimable and movable on pcp lists.
2402 * Free ISOLATE pages back to the allocator because they are being
2403 * offlined but treat RESERVE as movable pages so we can get those
2404 * areas back if necessary. Otherwise, we may have to free
2405 * excessively into the page allocator
2406 */
2407 if (migratetype >= MIGRATE_PCPTYPES) {
2408 if (unlikely(is_migrate_isolate(migratetype))) {
2409 free_one_page(zone, page, pfn, 0, migratetype);
2410 goto out;
2411 }
2412 migratetype = MIGRATE_MOVABLE;
2413 }
2414
2415 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2416 if (!cold)
2417 list_add(&page->lru, &pcp->lists[migratetype]);
2418 else
2419 list_add_tail(&page->lru, &pcp->lists[migratetype]);
2420 pcp->count++;
2421 if (pcp->count >= pcp->high) {
2422 unsigned long batch = READ_ONCE(pcp->batch);
2423 free_pcppages_bulk(zone, batch, pcp);
2424 pcp->count -= batch;
2425 }
2426
2427 out:
2428 local_irq_restore(flags);
2429 }
2430
2431 /*
2432 * Free a list of 0-order pages
2433 */
2434 void free_hot_cold_page_list(struct list_head *list, bool cold)
2435 {
2436 struct page *page, *next;
2437
2438 list_for_each_entry_safe(page, next, list, lru) {
2439 trace_mm_page_free_batched(page, cold);
2440 free_hot_cold_page(page, cold);
2441 }
2442 }
2443
2444 /*
2445 * split_page takes a non-compound higher-order page, and splits it into
2446 * n (1<<order) sub-pages: page[0..n]
2447 * Each sub-page must be freed individually.
2448 *
2449 * Note: this is probably too low level an operation for use in drivers.
2450 * Please consult with lkml before using this in your driver.
2451 */
2452 void split_page(struct page *page, unsigned int order)
2453 {
2454 int i;
2455 gfp_t gfp_mask;
2456
2457 VM_BUG_ON_PAGE(PageCompound(page), page);
2458 VM_BUG_ON_PAGE(!page_count(page), page);
2459
2460 #ifdef CONFIG_KMEMCHECK
2461 /*
2462 * Split shadow pages too, because free(page[0]) would
2463 * otherwise free the whole shadow.
2464 */
2465 if (kmemcheck_page_is_tracked(page))
2466 split_page(virt_to_page(page[0].shadow), order);
2467 #endif
2468
2469 gfp_mask = get_page_owner_gfp(page);
2470 set_page_owner(page, 0, gfp_mask);
2471 for (i = 1; i < (1 << order); i++) {
2472 set_page_refcounted(page + i);
2473 set_page_owner(page + i, 0, gfp_mask);
2474 }
2475 }
2476 EXPORT_SYMBOL_GPL(split_page);
2477
2478 int __isolate_free_page(struct page *page, unsigned int order)
2479 {
2480 unsigned long watermark;
2481 struct zone *zone;
2482 int mt;
2483
2484 BUG_ON(!PageBuddy(page));
2485
2486 zone = page_zone(page);
2487 mt = get_pageblock_migratetype(page);
2488
2489 if (!is_migrate_isolate(mt)) {
2490 /* Obey watermarks as if the page was being allocated */
2491 watermark = low_wmark_pages(zone) + (1 << order);
2492 if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
2493 return 0;
2494
2495 __mod_zone_freepage_state(zone, -(1UL << order), mt);
2496 }
2497
2498 /* Remove page from free list */
2499 list_del(&page->lru);
2500 zone->free_area[order].nr_free--;
2501 rmv_page_order(page);
2502
2503 set_page_owner(page, order, __GFP_MOVABLE);
2504
2505 /* Set the pageblock if the isolated page is at least a pageblock */
2506 if (order >= pageblock_order - 1) {
2507 struct page *endpage = page + (1 << order) - 1;
2508 for (; page < endpage; page += pageblock_nr_pages) {
2509 int mt = get_pageblock_migratetype(page);
2510 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt))
2511 set_pageblock_migratetype(page,
2512 MIGRATE_MOVABLE);
2513 }
2514 }
2515
2516
2517 return 1UL << order;
2518 }
2519
2520 /*
2521 * Similar to split_page except the page is already free. As this is only
2522 * being used for migration, the migratetype of the block also changes.
2523 * As this is called with interrupts disabled, the caller is responsible
2524 * for calling arch_alloc_page() and kernel_map_page() after interrupts
2525 * are enabled.
2526 *
2527 * Note: this is probably too low level an operation for use in drivers.
2528 * Please consult with lkml before using this in your driver.
2529 */
2530 int split_free_page(struct page *page)
2531 {
2532 unsigned int order;
2533 int nr_pages;
2534
2535 order = page_order(page);
2536
2537 nr_pages = __isolate_free_page(page, order);
2538 if (!nr_pages)
2539 return 0;
2540
2541 /* Split into individual pages */
2542 set_page_refcounted(page);
2543 split_page(page, order);
2544 return nr_pages;
2545 }
2546
2547 /*
2548 * Update NUMA hit/miss statistics
2549 *
2550 * Must be called with interrupts disabled.
2551 *
2552 * When __GFP_OTHER_NODE is set assume the node of the preferred
2553 * zone is the local node. This is useful for daemons who allocate
2554 * memory on behalf of other processes.
2555 */
2556 static inline void zone_statistics(struct zone *preferred_zone, struct zone *z,
2557 gfp_t flags)
2558 {
2559 #ifdef CONFIG_NUMA
2560 int local_nid = numa_node_id();
2561 enum zone_stat_item local_stat = NUMA_LOCAL;
2562
2563 if (unlikely(flags & __GFP_OTHER_NODE)) {
2564 local_stat = NUMA_OTHER;
2565 local_nid = preferred_zone->node;
2566 }
2567
2568 if (z->node == local_nid) {
2569 __inc_zone_state(z, NUMA_HIT);
2570 __inc_zone_state(z, local_stat);
2571 } else {
2572 __inc_zone_state(z, NUMA_MISS);
2573 __inc_zone_state(preferred_zone, NUMA_FOREIGN);
2574 }
2575 #endif
2576 }
2577
2578 /*
2579 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2580 */
2581 static inline
2582 struct page *buffered_rmqueue(struct zone *preferred_zone,
2583 struct zone *zone, unsigned int order,
2584 gfp_t gfp_flags, unsigned int alloc_flags,
2585 int migratetype)
2586 {
2587 unsigned long flags;
2588 struct page *page;
2589 bool cold = ((gfp_flags & __GFP_COLD) != 0);
2590
2591 if (likely(order == 0)) {
2592 struct per_cpu_pages *pcp;
2593 struct list_head *list;
2594
2595 local_irq_save(flags);
2596 pcp = &this_cpu_ptr(zone->pageset)->pcp;
2597 list = &pcp->lists[migratetype];
2598 if (list_empty(list)) {
2599 pcp->count += rmqueue_bulk(zone, 0,
2600 pcp->batch, list,
2601 migratetype, cold);
2602 if (unlikely(list_empty(list)))
2603 goto failed;
2604 }
2605
2606 if (cold)
2607 page = list_last_entry(list, struct page, lru);
2608 else
2609 page = list_first_entry(list, struct page, lru);
2610
2611 __dec_zone_state(zone, NR_ALLOC_BATCH);
2612 list_del(&page->lru);
2613 pcp->count--;
2614 } else {
2615 /*
2616 * We most definitely don't want callers attempting to
2617 * allocate greater than order-1 page units with __GFP_NOFAIL.
2618 */
2619 WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
2620 spin_lock_irqsave(&zone->lock, flags);
2621
2622 page = NULL;
2623 if (alloc_flags & ALLOC_HARDER) {
2624 page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);
2625 if (page)
2626 trace_mm_page_alloc_zone_locked(page, order, migratetype);
2627 }
2628 if (!page)
2629 page = __rmqueue(zone, order, migratetype);
2630 spin_unlock(&zone->lock);
2631 if (!page)
2632 goto failed;
2633 __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
2634 __mod_zone_freepage_state(zone, -(1 << order),
2635 get_pcppage_migratetype(page));
2636 }
2637
2638 if (atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]) <= 0 &&
2639 !test_bit(ZONE_FAIR_DEPLETED, &zone->flags))
2640 set_bit(ZONE_FAIR_DEPLETED, &zone->flags);
2641
2642 __count_zone_vm_events(PGALLOC, zone, 1 << order);
2643 zone_statistics(preferred_zone, zone, gfp_flags);
2644 local_irq_restore(flags);
2645
2646 VM_BUG_ON_PAGE(bad_range(zone, page), page);
2647 return page;
2648
2649 failed:
2650 local_irq_restore(flags);
2651 return NULL;
2652 }
2653
2654 #ifdef CONFIG_FAIL_PAGE_ALLOC
2655
2656 static struct {
2657 struct fault_attr attr;
2658
2659 bool ignore_gfp_highmem;
2660 bool ignore_gfp_reclaim;
2661 u32 min_order;
2662 } fail_page_alloc = {
2663 .attr = FAULT_ATTR_INITIALIZER,
2664 .ignore_gfp_reclaim = true,
2665 .ignore_gfp_highmem = true,
2666 .min_order = 1,
2667 };
2668
2669 static int __init setup_fail_page_alloc(char *str)
2670 {
2671 return setup_fault_attr(&fail_page_alloc.attr, str);
2672 }
2673 __setup("fail_page_alloc=", setup_fail_page_alloc);
2674
2675 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2676 {
2677 if (order < fail_page_alloc.min_order)
2678 return false;
2679 if (gfp_mask & __GFP_NOFAIL)
2680 return false;
2681 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
2682 return false;
2683 if (fail_page_alloc.ignore_gfp_reclaim &&
2684 (gfp_mask & __GFP_DIRECT_RECLAIM))
2685 return false;
2686
2687 return should_fail(&fail_page_alloc.attr, 1 << order);
2688 }
2689
2690 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2691
2692 static int __init fail_page_alloc_debugfs(void)
2693 {
2694 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
2695 struct dentry *dir;
2696
2697 dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
2698 &fail_page_alloc.attr);
2699 if (IS_ERR(dir))
2700 return PTR_ERR(dir);
2701
2702 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
2703 &fail_page_alloc.ignore_gfp_reclaim))
2704 goto fail;
2705 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
2706 &fail_page_alloc.ignore_gfp_highmem))
2707 goto fail;
2708 if (!debugfs_create_u32("min-order", mode, dir,
2709 &fail_page_alloc.min_order))
2710 goto fail;
2711
2712 return 0;
2713 fail:
2714 debugfs_remove_recursive(dir);
2715
2716 return -ENOMEM;
2717 }
2718
2719 late_initcall(fail_page_alloc_debugfs);
2720
2721 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2722
2723 #else /* CONFIG_FAIL_PAGE_ALLOC */
2724
2725 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
2726 {
2727 return false;
2728 }
2729
2730 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2731
2732 /*
2733 * Return true if free base pages are above 'mark'. For high-order checks it
2734 * will return true of the order-0 watermark is reached and there is at least
2735 * one free page of a suitable size. Checking now avoids taking the zone lock
2736 * to check in the allocation paths if no pages are free.
2737 */
2738 static bool __zone_watermark_ok(struct zone *z, unsigned int order,
2739 unsigned long mark, int classzone_idx,
2740 unsigned int alloc_flags,
2741 long free_pages)
2742 {
2743 long min = mark;
2744 int o;
2745 const bool alloc_harder = (alloc_flags & ALLOC_HARDER);
2746
2747 /* free_pages may go negative - that's OK */
2748 free_pages -= (1 << order) - 1;
2749
2750 if (alloc_flags & ALLOC_HIGH)
2751 min -= min / 2;
2752
2753 /*
2754 * If the caller does not have rights to ALLOC_HARDER then subtract
2755 * the high-atomic reserves. This will over-estimate the size of the
2756 * atomic reserve but it avoids a search.
2757 */
2758 if (likely(!alloc_harder))
2759 free_pages -= z->nr_reserved_highatomic;
2760 else
2761 min -= min / 4;
2762
2763 #ifdef CONFIG_CMA
2764 /* If allocation can't use CMA areas don't use free CMA pages */
2765 if (!(alloc_flags & ALLOC_CMA))
2766 free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES);
2767 #endif
2768
2769 /*
2770 * Check watermarks for an order-0 allocation request. If these
2771 * are not met, then a high-order request also cannot go ahead
2772 * even if a suitable page happened to be free.
2773 */
2774 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
2775 return false;
2776
2777 /* If this is an order-0 request then the watermark is fine */
2778 if (!order)
2779 return true;
2780
2781 /* For a high-order request, check at least one suitable page is free */
2782 for (o = order; o < MAX_ORDER; o++) {
2783 struct free_area *area = &z->free_area[o];
2784 int mt;
2785
2786 if (!area->nr_free)
2787 continue;
2788
2789 if (alloc_harder)
2790 return true;
2791
2792 for (mt = 0; mt < MIGRATE_PCPTYPES; mt++) {
2793 if (!list_empty(&area->free_list[mt]))
2794 return true;
2795 }
2796
2797 #ifdef CONFIG_CMA
2798 if ((alloc_flags & ALLOC_CMA) &&
2799 !list_empty(&area->free_list[MIGRATE_CMA])) {
2800 return true;
2801 }
2802 #endif
2803 }
2804 return false;
2805 }
2806
2807 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
2808 int classzone_idx, unsigned int alloc_flags)
2809 {
2810 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
2811 zone_page_state(z, NR_FREE_PAGES));
2812 }
2813
2814 static inline bool zone_watermark_fast(struct zone *z, unsigned int order,
2815 unsigned long mark, int classzone_idx, unsigned int alloc_flags)
2816 {
2817 long free_pages = zone_page_state(z, NR_FREE_PAGES);
2818 long cma_pages = 0;
2819
2820 #ifdef CONFIG_CMA
2821 /* If allocation can't use CMA areas don't use free CMA pages */
2822 if (!(alloc_flags & ALLOC_CMA))
2823 cma_pages = zone_page_state(z, NR_FREE_CMA_PAGES);
2824 #endif
2825
2826 /*
2827 * Fast check for order-0 only. If this fails then the reserves
2828 * need to be calculated. There is a corner case where the check
2829 * passes but only the high-order atomic reserve are free. If
2830 * the caller is !atomic then it'll uselessly search the free
2831 * list. That corner case is then slower but it is harmless.
2832 */
2833 if (!order && (free_pages - cma_pages) > mark + z->lowmem_reserve[classzone_idx])
2834 return true;
2835
2836 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
2837 free_pages);
2838 }
2839
2840 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
2841 unsigned long mark, int classzone_idx)
2842 {
2843 long free_pages = zone_page_state(z, NR_FREE_PAGES);
2844
2845 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
2846 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
2847
2848 return __zone_watermark_ok(z, order, mark, classzone_idx, 0,
2849 free_pages);
2850 }
2851
2852 #ifdef CONFIG_NUMA
2853 static bool zone_local(struct zone *local_zone, struct zone *zone)
2854 {
2855 return local_zone->node == zone->node;
2856 }
2857
2858 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2859 {
2860 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <
2861 RECLAIM_DISTANCE;
2862 }
2863 #else /* CONFIG_NUMA */
2864 static bool zone_local(struct zone *local_zone, struct zone *zone)
2865 {
2866 return true;
2867 }
2868
2869 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
2870 {
2871 return true;
2872 }
2873 #endif /* CONFIG_NUMA */
2874
2875 static void reset_alloc_batches(struct zone *preferred_zone)
2876 {
2877 struct zone *zone = preferred_zone->zone_pgdat->node_zones;
2878
2879 do {
2880 mod_zone_page_state(zone, NR_ALLOC_BATCH,
2881 high_wmark_pages(zone) - low_wmark_pages(zone) -
2882 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
2883 clear_bit(ZONE_FAIR_DEPLETED, &zone->flags);
2884 } while (zone++ != preferred_zone);
2885 }
2886
2887 /*
2888 * get_page_from_freelist goes through the zonelist trying to allocate
2889 * a page.
2890 */
2891 static struct page *
2892 get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
2893 const struct alloc_context *ac)
2894 {
2895 struct zoneref *z = ac->preferred_zoneref;
2896 struct zone *zone;
2897 bool fair_skipped = false;
2898 bool apply_fair = (alloc_flags & ALLOC_FAIR);
2899
2900 zonelist_scan:
2901 /*
2902 * Scan zonelist, looking for a zone with enough free.
2903 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2904 */
2905 for_next_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
2906 ac->nodemask) {
2907 struct page *page;
2908 unsigned long mark;
2909
2910 if (cpusets_enabled() &&
2911 (alloc_flags & ALLOC_CPUSET) &&
2912 !__cpuset_zone_allowed(zone, gfp_mask))
2913 continue;
2914 /*
2915 * Distribute pages in proportion to the individual
2916 * zone size to ensure fair page aging. The zone a
2917 * page was allocated in should have no effect on the
2918 * time the page has in memory before being reclaimed.
2919 */
2920 if (apply_fair) {
2921 if (test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) {
2922 fair_skipped = true;
2923 continue;
2924 }
2925 if (!zone_local(ac->preferred_zoneref->zone, zone)) {
2926 if (fair_skipped)
2927 goto reset_fair;
2928 apply_fair = false;
2929 }
2930 }
2931 /*
2932 * When allocating a page cache page for writing, we
2933 * want to get it from a zone that is within its dirty
2934 * limit, such that no single zone holds more than its
2935 * proportional share of globally allowed dirty pages.
2936 * The dirty limits take into account the zone's
2937 * lowmem reserves and high watermark so that kswapd
2938 * should be able to balance it without having to
2939 * write pages from its LRU list.
2940 *
2941 * This may look like it could increase pressure on
2942 * lower zones by failing allocations in higher zones
2943 * before they are full. But the pages that do spill
2944 * over are limited as the lower zones are protected
2945 * by this very same mechanism. It should not become
2946 * a practical burden to them.
2947 *
2948 * XXX: For now, allow allocations to potentially
2949 * exceed the per-zone dirty limit in the slowpath
2950 * (spread_dirty_pages unset) before going into reclaim,
2951 * which is important when on a NUMA setup the allowed
2952 * zones are together not big enough to reach the
2953 * global limit. The proper fix for these situations
2954 * will require awareness of zones in the
2955 * dirty-throttling and the flusher threads.
2956 */
2957 if (ac->spread_dirty_pages && !zone_dirty_ok(zone))
2958 continue;
2959
2960 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
2961 if (!zone_watermark_fast(zone, order, mark,
2962 ac_classzone_idx(ac), alloc_flags)) {
2963 int ret;
2964
2965 /* Checked here to keep the fast path fast */
2966 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
2967 if (alloc_flags & ALLOC_NO_WATERMARKS)
2968 goto try_this_zone;
2969
2970 if (zone_reclaim_mode == 0 ||
2971 !zone_allows_reclaim(ac->preferred_zoneref->zone, zone))
2972 continue;
2973
2974 ret = zone_reclaim(zone, gfp_mask, order);
2975 switch (ret) {
2976 case ZONE_RECLAIM_NOSCAN:
2977 /* did not scan */
2978 continue;
2979 case ZONE_RECLAIM_FULL:
2980 /* scanned but unreclaimable */
2981 continue;
2982 default:
2983 /* did we reclaim enough */
2984 if (zone_watermark_ok(zone, order, mark,
2985 ac_classzone_idx(ac), alloc_flags))
2986 goto try_this_zone;
2987
2988 continue;
2989 }
2990 }
2991
2992 try_this_zone:
2993 page = buffered_rmqueue(ac->preferred_zoneref->zone, zone, order,
2994 gfp_mask, alloc_flags, ac->migratetype);
2995 if (page) {
2996 if (prep_new_page(page, order, gfp_mask, alloc_flags))
2997 goto try_this_zone;
2998
2999 /*
3000 * If this is a high-order atomic allocation then check
3001 * if the pageblock should be reserved for the future
3002 */
3003 if (unlikely(order && (alloc_flags & ALLOC_HARDER)))
3004 reserve_highatomic_pageblock(page, zone, order);
3005
3006 return page;
3007 }
3008 }
3009
3010 /*
3011 * The first pass makes sure allocations are spread fairly within the
3012 * local node. However, the local node might have free pages left
3013 * after the fairness batches are exhausted, and remote zones haven't
3014 * even been considered yet. Try once more without fairness, and
3015 * include remote zones now, before entering the slowpath and waking
3016 * kswapd: prefer spilling to a remote zone over swapping locally.
3017 */
3018 if (fair_skipped) {
3019 reset_fair:
3020 apply_fair = false;
3021 fair_skipped = false;
3022 reset_alloc_batches(ac->preferred_zoneref->zone);
3023 goto zonelist_scan;
3024 }
3025
3026 return NULL;
3027 }
3028
3029 /*
3030 * Large machines with many possible nodes should not always dump per-node
3031 * meminfo in irq context.
3032 */
3033 static inline bool should_suppress_show_mem(void)
3034 {
3035 bool ret = false;
3036
3037 #if NODES_SHIFT > 8
3038 ret = in_interrupt();
3039 #endif
3040 return ret;
3041 }
3042
3043 static DEFINE_RATELIMIT_STATE(nopage_rs,
3044 DEFAULT_RATELIMIT_INTERVAL,
3045 DEFAULT_RATELIMIT_BURST);
3046
3047 void warn_alloc_failed(gfp_t gfp_mask, unsigned int order, const char *fmt, ...)
3048 {
3049 unsigned int filter = SHOW_MEM_FILTER_NODES;
3050
3051 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
3052 debug_guardpage_minorder() > 0)
3053 return;
3054
3055 /*
3056 * This documents exceptions given to allocations in certain
3057 * contexts that are allowed to allocate outside current's set
3058 * of allowed nodes.
3059 */
3060 if (!(gfp_mask & __GFP_NOMEMALLOC))
3061 if (test_thread_flag(TIF_MEMDIE) ||
3062 (current->flags & (PF_MEMALLOC | PF_EXITING)))
3063 filter &= ~SHOW_MEM_FILTER_NODES;
3064 if (in_interrupt() || !(gfp_mask & __GFP_DIRECT_RECLAIM))
3065 filter &= ~SHOW_MEM_FILTER_NODES;
3066
3067 if (fmt) {
3068 struct va_format vaf;
3069 va_list args;
3070
3071 va_start(args, fmt);
3072
3073 vaf.fmt = fmt;
3074 vaf.va = &args;
3075
3076 pr_warn("%pV", &vaf);
3077
3078 va_end(args);
3079 }
3080
3081 pr_warn("%s: page allocation failure: order:%u, mode:%#x(%pGg)\n",
3082 current->comm, order, gfp_mask, &gfp_mask);
3083 dump_stack();
3084 if (!should_suppress_show_mem())
3085 show_mem(filter);
3086 }
3087
3088 static inline struct page *
3089 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
3090 const struct alloc_context *ac, unsigned long *did_some_progress)
3091 {
3092 struct oom_control oc = {
3093 .zonelist = ac->zonelist,
3094 .nodemask = ac->nodemask,
3095 .gfp_mask = gfp_mask,
3096 .order = order,
3097 };
3098 struct page *page;
3099
3100 *did_some_progress = 0;
3101
3102 /*
3103 * Acquire the oom lock. If that fails, somebody else is
3104 * making progress for us.
3105 */
3106 if (!mutex_trylock(&oom_lock)) {
3107 *did_some_progress = 1;
3108 schedule_timeout_uninterruptible(1);
3109 return NULL;
3110 }
3111
3112 /*
3113 * Go through the zonelist yet one more time, keep very high watermark
3114 * here, this is only to catch a parallel oom killing, we must fail if
3115 * we're still under heavy pressure.
3116 */
3117 page = get_page_from_freelist(gfp_mask | __GFP_HARDWALL, order,
3118 ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
3119 if (page)
3120 goto out;
3121
3122 if (!(gfp_mask & __GFP_NOFAIL)) {
3123 /* Coredumps can quickly deplete all memory reserves */
3124 if (current->flags & PF_DUMPCORE)
3125 goto out;
3126 /* The OOM killer will not help higher order allocs */
3127 if (order > PAGE_ALLOC_COSTLY_ORDER)
3128 goto out;
3129 /* The OOM killer does not needlessly kill tasks for lowmem */
3130 if (ac->high_zoneidx < ZONE_NORMAL)
3131 goto out;
3132 if (pm_suspended_storage())
3133 goto out;
3134 /*
3135 * XXX: GFP_NOFS allocations should rather fail than rely on
3136 * other request to make a forward progress.
3137 * We are in an unfortunate situation where out_of_memory cannot
3138 * do much for this context but let's try it to at least get
3139 * access to memory reserved if the current task is killed (see
3140 * out_of_memory). Once filesystems are ready to handle allocation
3141 * failures more gracefully we should just bail out here.
3142 */
3143
3144 /* The OOM killer may not free memory on a specific node */
3145 if (gfp_mask & __GFP_THISNODE)
3146 goto out;
3147 }
3148 /* Exhausted what can be done so it's blamo time */
3149 if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
3150 *did_some_progress = 1;
3151
3152 if (gfp_mask & __GFP_NOFAIL) {
3153 page = get_page_from_freelist(gfp_mask, order,
3154 ALLOC_NO_WATERMARKS|ALLOC_CPUSET, ac);
3155 /*
3156 * fallback to ignore cpuset restriction if our nodes
3157 * are depleted
3158 */
3159 if (!page)
3160 page = get_page_from_freelist(gfp_mask, order,
3161 ALLOC_NO_WATERMARKS, ac);
3162 }
3163 }
3164 out:
3165 mutex_unlock(&oom_lock);
3166 return page;
3167 }
3168
3169 #ifdef CONFIG_COMPACTION
3170 /* Try memory compaction for high-order allocations before reclaim */
3171 static struct page *
3172 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
3173 unsigned int alloc_flags, const struct alloc_context *ac,
3174 enum migrate_mode mode, int *contended_compaction,
3175 bool *deferred_compaction)
3176 {
3177 unsigned long compact_result;
3178 struct page *page;
3179
3180 if (!order)
3181 return NULL;
3182
3183 current->flags |= PF_MEMALLOC;
3184 compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
3185 mode, contended_compaction);
3186 current->flags &= ~PF_MEMALLOC;
3187
3188 switch (compact_result) {
3189 case COMPACT_DEFERRED:
3190 *deferred_compaction = true;
3191 /* fall-through */
3192 case COMPACT_SKIPPED:
3193 return NULL;
3194 default:
3195 break;
3196 }
3197
3198 /*
3199 * At least in one zone compaction wasn't deferred or skipped, so let's
3200 * count a compaction stall
3201 */
3202 count_vm_event(COMPACTSTALL);
3203
3204 page = get_page_from_freelist(gfp_mask, order,
3205 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
3206
3207 if (page) {
3208 struct zone *zone = page_zone(page);
3209
3210 zone->compact_blockskip_flush = false;
3211 compaction_defer_reset(zone, order, true);
3212 count_vm_event(COMPACTSUCCESS);
3213 return page;
3214 }
3215
3216 /*
3217 * It's bad if compaction run occurs and fails. The most likely reason
3218 * is that pages exist, but not enough to satisfy watermarks.
3219 */
3220 count_vm_event(COMPACTFAIL);
3221
3222 cond_resched();
3223
3224 return NULL;
3225 }
3226 #else
3227 static inline struct page *
3228 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
3229 unsigned int alloc_flags, const struct alloc_context *ac,
3230 enum migrate_mode mode, int *contended_compaction,
3231 bool *deferred_compaction)
3232 {
3233 return NULL;
3234 }
3235 #endif /* CONFIG_COMPACTION */
3236
3237 /* Perform direct synchronous page reclaim */
3238 static int
3239 __perform_reclaim(gfp_t gfp_mask, unsigned int order,
3240 const struct alloc_context *ac)
3241 {
3242 struct reclaim_state reclaim_state;
3243 int progress;
3244
3245 cond_resched();
3246
3247 /* We now go into synchronous reclaim */
3248 cpuset_memory_pressure_bump();
3249 current->flags |= PF_MEMALLOC;
3250 lockdep_set_current_reclaim_state(gfp_mask);
3251 reclaim_state.reclaimed_slab = 0;
3252 current->reclaim_state = &reclaim_state;
3253
3254 progress = try_to_free_pages(ac->zonelist, order, gfp_mask,
3255 ac->nodemask);
3256
3257 current->reclaim_state = NULL;
3258 lockdep_clear_current_reclaim_state();
3259 current->flags &= ~PF_MEMALLOC;
3260
3261 cond_resched();
3262
3263 return progress;
3264 }
3265
3266 /* The really slow allocator path where we enter direct reclaim */
3267 static inline struct page *
3268 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
3269 unsigned int alloc_flags, const struct alloc_context *ac,
3270 unsigned long *did_some_progress)
3271 {
3272 struct page *page = NULL;
3273 bool drained = false;
3274
3275 *did_some_progress = __perform_reclaim(gfp_mask, order, ac);
3276 if (unlikely(!(*did_some_progress)))
3277 return NULL;
3278
3279 retry:
3280 page = get_page_from_freelist(gfp_mask, order,
3281 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
3282
3283 /*
3284 * If an allocation failed after direct reclaim, it could be because
3285 * pages are pinned on the per-cpu lists or in high alloc reserves.
3286 * Shrink them them and try again
3287 */
3288 if (!page && !drained) {
3289 unreserve_highatomic_pageblock(ac);
3290 drain_all_pages(NULL);
3291 drained = true;
3292 goto retry;
3293 }
3294
3295 return page;
3296 }
3297
3298 static void wake_all_kswapds(unsigned int order, const struct alloc_context *ac)
3299 {
3300 struct zoneref *z;
3301 struct zone *zone;
3302
3303 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
3304 ac->high_zoneidx, ac->nodemask)
3305 wakeup_kswapd(zone, order, ac_classzone_idx(ac));
3306 }
3307
3308 static inline unsigned int
3309 gfp_to_alloc_flags(gfp_t gfp_mask)
3310 {
3311 unsigned int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
3312
3313 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3314 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
3315
3316 /*
3317 * The caller may dip into page reserves a bit more if the caller
3318 * cannot run direct reclaim, or if the caller has realtime scheduling
3319 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3320 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3321 */
3322 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
3323
3324 if (gfp_mask & __GFP_ATOMIC) {
3325 /*
3326 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3327 * if it can't schedule.
3328 */
3329 if (!(gfp_mask & __GFP_NOMEMALLOC))
3330 alloc_flags |= ALLOC_HARDER;
3331 /*
3332 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3333 * comment for __cpuset_node_allowed().
3334 */
3335 alloc_flags &= ~ALLOC_CPUSET;
3336 } else if (unlikely(rt_task(current)) && !in_interrupt())
3337 alloc_flags |= ALLOC_HARDER;
3338
3339 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
3340 if (gfp_mask & __GFP_MEMALLOC)
3341 alloc_flags |= ALLOC_NO_WATERMARKS;
3342 else if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
3343 alloc_flags |= ALLOC_NO_WATERMARKS;
3344 else if (!in_interrupt() &&
3345 ((current->flags & PF_MEMALLOC) ||
3346 unlikely(test_thread_flag(TIF_MEMDIE))))
3347 alloc_flags |= ALLOC_NO_WATERMARKS;
3348 }
3349 #ifdef CONFIG_CMA
3350 if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
3351 alloc_flags |= ALLOC_CMA;
3352 #endif
3353 return alloc_flags;
3354 }
3355
3356 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
3357 {
3358 return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS);
3359 }
3360
3361 static inline bool is_thp_gfp_mask(gfp_t gfp_mask)
3362 {
3363 return (gfp_mask & (GFP_TRANSHUGE | __GFP_KSWAPD_RECLAIM)) == GFP_TRANSHUGE;
3364 }
3365
3366 static inline struct page *
3367 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
3368 struct alloc_context *ac)
3369 {
3370 bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM;
3371 struct page *page = NULL;
3372 unsigned int alloc_flags;
3373 unsigned long pages_reclaimed = 0;
3374 unsigned long did_some_progress;
3375 enum migrate_mode migration_mode = MIGRATE_ASYNC;
3376 bool deferred_compaction = false;
3377 int contended_compaction = COMPACT_CONTENDED_NONE;
3378
3379 /*
3380 * In the slowpath, we sanity check order to avoid ever trying to
3381 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3382 * be using allocators in order of preference for an area that is
3383 * too large.
3384 */
3385 if (order >= MAX_ORDER) {
3386 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
3387 return NULL;
3388 }
3389
3390 /*
3391 * We also sanity check to catch abuse of atomic reserves being used by
3392 * callers that are not in atomic context.
3393 */
3394 if (WARN_ON_ONCE((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) ==
3395 (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)))
3396 gfp_mask &= ~__GFP_ATOMIC;
3397
3398 retry:
3399 if (gfp_mask & __GFP_KSWAPD_RECLAIM)
3400 wake_all_kswapds(order, ac);
3401
3402 /*
3403 * OK, we're below the kswapd watermark and have kicked background
3404 * reclaim. Now things get more complex, so set up alloc_flags according
3405 * to how we want to proceed.
3406 */
3407 alloc_flags = gfp_to_alloc_flags(gfp_mask);
3408
3409 /* This is the last chance, in general, before the goto nopage. */
3410 page = get_page_from_freelist(gfp_mask, order,
3411 alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
3412 if (page)
3413 goto got_pg;
3414
3415 /* Allocate without watermarks if the context allows */
3416 if (alloc_flags & ALLOC_NO_WATERMARKS) {
3417 /*
3418 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
3419 * the allocation is high priority and these type of
3420 * allocations are system rather than user orientated
3421 */
3422 ac->zonelist = node_zonelist(numa_node_id(), gfp_mask);
3423 page = get_page_from_freelist(gfp_mask, order,
3424 ALLOC_NO_WATERMARKS, ac);
3425 if (page)
3426 goto got_pg;
3427 }
3428
3429 /* Caller is not willing to reclaim, we can't balance anything */
3430 if (!can_direct_reclaim) {
3431 /*
3432 * All existing users of the __GFP_NOFAIL are blockable, so warn
3433 * of any new users that actually allow this type of allocation
3434 * to fail.
3435 */
3436 WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL);
3437 goto nopage;
3438 }
3439
3440 /* Avoid recursion of direct reclaim */
3441 if (current->flags & PF_MEMALLOC) {
3442 /*
3443 * __GFP_NOFAIL request from this context is rather bizarre
3444 * because we cannot reclaim anything and only can loop waiting
3445 * for somebody to do a work for us.
3446 */
3447 if (WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
3448 cond_resched();
3449 goto retry;
3450 }
3451 goto nopage;
3452 }
3453
3454 /* Avoid allocations with no watermarks from looping endlessly */
3455 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
3456 goto nopage;
3457
3458 /*
3459 * Try direct compaction. The first pass is asynchronous. Subsequent
3460 * attempts after direct reclaim are synchronous
3461 */
3462 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
3463 migration_mode,
3464 &contended_compaction,
3465 &deferred_compaction);
3466 if (page)
3467 goto got_pg;
3468
3469 /* Checks for THP-specific high-order allocations */
3470 if (is_thp_gfp_mask(gfp_mask)) {
3471 /*
3472 * If compaction is deferred for high-order allocations, it is
3473 * because sync compaction recently failed. If this is the case
3474 * and the caller requested a THP allocation, we do not want
3475 * to heavily disrupt the system, so we fail the allocation
3476 * instead of entering direct reclaim.
3477 */
3478 if (deferred_compaction)
3479 goto nopage;
3480
3481 /*
3482 * In all zones where compaction was attempted (and not
3483 * deferred or skipped), lock contention has been detected.
3484 * For THP allocation we do not want to disrupt the others
3485 * so we fallback to base pages instead.
3486 */
3487 if (contended_compaction == COMPACT_CONTENDED_LOCK)
3488 goto nopage;
3489
3490 /*
3491 * If compaction was aborted due to need_resched(), we do not
3492 * want to further increase allocation latency, unless it is
3493 * khugepaged trying to collapse.
3494 */
3495 if (contended_compaction == COMPACT_CONTENDED_SCHED
3496 && !(current->flags & PF_KTHREAD))
3497 goto nopage;
3498 }
3499
3500 /*
3501 * It can become very expensive to allocate transparent hugepages at
3502 * fault, so use asynchronous memory compaction for THP unless it is
3503 * khugepaged trying to collapse.
3504 */
3505 if (!is_thp_gfp_mask(gfp_mask) || (current->flags & PF_KTHREAD))
3506 migration_mode = MIGRATE_SYNC_LIGHT;
3507
3508 /* Try direct reclaim and then allocating */
3509 page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac,
3510 &did_some_progress);
3511 if (page)
3512 goto got_pg;
3513
3514 /* Do not loop if specifically requested */
3515 if (gfp_mask & __GFP_NORETRY)
3516 goto noretry;
3517
3518 /* Keep reclaiming pages as long as there is reasonable progress */
3519 pages_reclaimed += did_some_progress;
3520 if ((did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER) ||
3521 ((gfp_mask & __GFP_REPEAT) && pages_reclaimed < (1 << order))) {
3522 /* Wait for some write requests to complete then retry */
3523 wait_iff_congested(ac->preferred_zoneref->zone, BLK_RW_ASYNC, HZ/50);
3524 goto retry;
3525 }
3526
3527 /* Reclaim has failed us, start killing things */
3528 page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
3529 if (page)
3530 goto got_pg;
3531
3532 /* Retry as long as the OOM killer is making progress */
3533 if (did_some_progress)
3534 goto retry;
3535
3536 noretry:
3537 /*
3538 * High-order allocations do not necessarily loop after
3539 * direct reclaim and reclaim/compaction depends on compaction
3540 * being called after reclaim so call directly if necessary
3541 */
3542 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags,
3543 ac, migration_mode,
3544 &contended_compaction,
3545 &deferred_compaction);
3546 if (page)
3547 goto got_pg;
3548 nopage:
3549 warn_alloc_failed(gfp_mask, order, NULL);
3550 got_pg:
3551 return page;
3552 }
3553
3554 /*
3555 * This is the 'heart' of the zoned buddy allocator.
3556 */
3557 struct page *
3558 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
3559 struct zonelist *zonelist, nodemask_t *nodemask)
3560 {
3561 struct page *page;
3562 unsigned int cpuset_mems_cookie;
3563 unsigned int alloc_flags = ALLOC_WMARK_LOW|ALLOC_FAIR;
3564 gfp_t alloc_mask = gfp_mask; /* The gfp_t that was actually used for allocation */
3565 struct alloc_context ac = {
3566 .high_zoneidx = gfp_zone(gfp_mask),
3567 .zonelist = zonelist,
3568 .nodemask = nodemask,
3569 .migratetype = gfpflags_to_migratetype(gfp_mask),
3570 };
3571
3572 if (cpusets_enabled()) {
3573 alloc_mask |= __GFP_HARDWALL;
3574 alloc_flags |= ALLOC_CPUSET;
3575 if (!ac.nodemask)
3576 ac.nodemask = &cpuset_current_mems_allowed;
3577 }
3578
3579 gfp_mask &= gfp_allowed_mask;
3580
3581 lockdep_trace_alloc(gfp_mask);
3582
3583 might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM);
3584
3585 if (should_fail_alloc_page(gfp_mask, order))
3586 return NULL;
3587
3588 /*
3589 * Check the zones suitable for the gfp_mask contain at least one
3590 * valid zone. It's possible to have an empty zonelist as a result
3591 * of __GFP_THISNODE and a memoryless node
3592 */
3593 if (unlikely(!zonelist->_zonerefs->zone))
3594 return NULL;
3595
3596 if (IS_ENABLED(CONFIG_CMA) && ac.migratetype == MIGRATE_MOVABLE)
3597 alloc_flags |= ALLOC_CMA;
3598
3599 retry_cpuset:
3600 cpuset_mems_cookie = read_mems_allowed_begin();
3601
3602 /* Dirty zone balancing only done in the fast path */
3603 ac.spread_dirty_pages = (gfp_mask & __GFP_WRITE);
3604
3605 /* The preferred zone is used for statistics later */
3606 ac.preferred_zoneref = first_zones_zonelist(ac.zonelist,
3607 ac.high_zoneidx, ac.nodemask);
3608 if (!ac.preferred_zoneref) {
3609 page = NULL;
3610 goto no_zone;
3611 }
3612
3613 /* First allocation attempt */
3614 page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);
3615 if (likely(page))
3616 goto out;
3617
3618 /*
3619 * Runtime PM, block IO and its error handling path can deadlock
3620 * because I/O on the device might not complete.
3621 */
3622 alloc_mask = memalloc_noio_flags(gfp_mask);
3623 ac.spread_dirty_pages = false;
3624
3625 page = __alloc_pages_slowpath(alloc_mask, order, &ac);
3626
3627 no_zone:
3628 /*
3629 * When updating a task's mems_allowed, it is possible to race with
3630 * parallel threads in such a way that an allocation can fail while
3631 * the mask is being updated. If a page allocation is about to fail,
3632 * check if the cpuset changed during allocation and if so, retry.
3633 */
3634 if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie))) {
3635 alloc_mask = gfp_mask;
3636 goto retry_cpuset;
3637 }
3638
3639 out:
3640 if (kmemcheck_enabled && page)
3641 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
3642
3643 trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);
3644
3645 return page;
3646 }
3647 EXPORT_SYMBOL(__alloc_pages_nodemask);
3648
3649 /*
3650 * Common helper functions.
3651 */
3652 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
3653 {
3654 struct page *page;
3655
3656 /*
3657 * __get_free_pages() returns a 32-bit address, which cannot represent
3658 * a highmem page
3659 */
3660 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
3661
3662 page = alloc_pages(gfp_mask, order);
3663 if (!page)
3664 return 0;
3665 return (unsigned long) page_address(page);
3666 }
3667 EXPORT_SYMBOL(__get_free_pages);
3668
3669 unsigned long get_zeroed_page(gfp_t gfp_mask)
3670 {
3671 return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
3672 }
3673 EXPORT_SYMBOL(get_zeroed_page);
3674
3675 void __free_pages(struct page *page, unsigned int order)
3676 {
3677 if (put_page_testzero(page)) {
3678 if (order == 0)
3679 free_hot_cold_page(page, false);
3680 else
3681 __free_pages_ok(page, order);
3682 }
3683 }
3684
3685 EXPORT_SYMBOL(__free_pages);
3686
3687 void free_pages(unsigned long addr, unsigned int order)
3688 {
3689 if (addr != 0) {
3690 VM_BUG_ON(!virt_addr_valid((void *)addr));
3691 __free_pages(virt_to_page((void *)addr), order);
3692 }
3693 }
3694
3695 EXPORT_SYMBOL(free_pages);
3696
3697 /*
3698 * Page Fragment:
3699 * An arbitrary-length arbitrary-offset area of memory which resides
3700 * within a 0 or higher order page. Multiple fragments within that page
3701 * are individually refcounted, in the page's reference counter.
3702 *
3703 * The page_frag functions below provide a simple allocation framework for
3704 * page fragments. This is used by the network stack and network device
3705 * drivers to provide a backing region of memory for use as either an
3706 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3707 */
3708 static struct page *__page_frag_refill(struct page_frag_cache *nc,
3709 gfp_t gfp_mask)
3710 {
3711 struct page *page = NULL;
3712 gfp_t gfp = gfp_mask;
3713
3714 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3715 gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY |
3716 __GFP_NOMEMALLOC;
3717 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask,
3718 PAGE_FRAG_CACHE_MAX_ORDER);
3719 nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE;
3720 #endif
3721 if (unlikely(!page))
3722 page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
3723
3724 nc->va = page ? page_address(page) : NULL;
3725
3726 return page;
3727 }
3728
3729 void *__alloc_page_frag(struct page_frag_cache *nc,
3730 unsigned int fragsz, gfp_t gfp_mask)
3731 {
3732 unsigned int size = PAGE_SIZE;
3733 struct page *page;
3734 int offset;
3735
3736 if (unlikely(!nc->va)) {
3737 refill:
3738 page = __page_frag_refill(nc, gfp_mask);
3739 if (!page)
3740 return NULL;
3741
3742 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3743 /* if size can vary use size else just use PAGE_SIZE */
3744 size = nc->size;
3745 #endif
3746 /* Even if we own the page, we do not use atomic_set().
3747 * This would break get_page_unless_zero() users.
3748 */
3749 page_ref_add(page, size - 1);
3750
3751 /* reset page count bias and offset to start of new frag */
3752 nc->pfmemalloc = page_is_pfmemalloc(page);
3753 nc->pagecnt_bias = size;
3754 nc->offset = size;
3755 }
3756
3757 offset = nc->offset - fragsz;
3758 if (unlikely(offset < 0)) {
3759 page = virt_to_page(nc->va);
3760
3761 if (!page_ref_sub_and_test(page, nc->pagecnt_bias))
3762 goto refill;
3763
3764 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3765 /* if size can vary use size else just use PAGE_SIZE */
3766 size = nc->size;
3767 #endif
3768 /* OK, page count is 0, we can safely set it */
3769 set_page_count(page, size);
3770
3771 /* reset page count bias and offset to start of new frag */
3772 nc->pagecnt_bias = size;
3773 offset = size - fragsz;
3774 }
3775
3776 nc->pagecnt_bias--;
3777 nc->offset = offset;
3778
3779 return nc->va + offset;
3780 }
3781 EXPORT_SYMBOL(__alloc_page_frag);
3782
3783 /*
3784 * Frees a page fragment allocated out of either a compound or order 0 page.
3785 */
3786 void __free_page_frag(void *addr)
3787 {
3788 struct page *page = virt_to_head_page(addr);
3789
3790 if (unlikely(put_page_testzero(page)))
3791 __free_pages_ok(page, compound_order(page));
3792 }
3793 EXPORT_SYMBOL(__free_page_frag);
3794
3795 /*
3796 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
3797 * of the current memory cgroup if __GFP_ACCOUNT is set, other than that it is
3798 * equivalent to alloc_pages.
3799 *
3800 * It should be used when the caller would like to use kmalloc, but since the
3801 * allocation is large, it has to fall back to the page allocator.
3802 */
3803 struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order)
3804 {
3805 struct page *page;
3806
3807 page = alloc_pages(gfp_mask, order);
3808 if (page && memcg_kmem_charge(page, gfp_mask, order) != 0) {
3809 __free_pages(page, order);
3810 page = NULL;
3811 }
3812 return page;
3813 }
3814
3815 struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
3816 {
3817 struct page *page;
3818
3819 page = alloc_pages_node(nid, gfp_mask, order);
3820 if (page && memcg_kmem_charge(page, gfp_mask, order) != 0) {
3821 __free_pages(page, order);
3822 page = NULL;
3823 }
3824 return page;
3825 }
3826
3827 /*
3828 * __free_kmem_pages and free_kmem_pages will free pages allocated with
3829 * alloc_kmem_pages.
3830 */
3831 void __free_kmem_pages(struct page *page, unsigned int order)
3832 {
3833 memcg_kmem_uncharge(page, order);
3834 __free_pages(page, order);
3835 }
3836
3837 void free_kmem_pages(unsigned long addr, unsigned int order)
3838 {
3839 if (addr != 0) {
3840 VM_BUG_ON(!virt_addr_valid((void *)addr));
3841 __free_kmem_pages(virt_to_page((void *)addr), order);
3842 }
3843 }
3844
3845 static void *make_alloc_exact(unsigned long addr, unsigned int order,
3846 size_t size)
3847 {
3848 if (addr) {
3849 unsigned long alloc_end = addr + (PAGE_SIZE << order);
3850 unsigned long used = addr + PAGE_ALIGN(size);
3851
3852 split_page(virt_to_page((void *)addr), order);
3853 while (used < alloc_end) {
3854 free_page(used);
3855 used += PAGE_SIZE;
3856 }
3857 }
3858 return (void *)addr;
3859 }
3860
3861 /**
3862 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
3863 * @size: the number of bytes to allocate
3864 * @gfp_mask: GFP flags for the allocation
3865 *
3866 * This function is similar to alloc_pages(), except that it allocates the
3867 * minimum number of pages to satisfy the request. alloc_pages() can only
3868 * allocate memory in power-of-two pages.
3869 *
3870 * This function is also limited by MAX_ORDER.
3871 *
3872 * Memory allocated by this function must be released by free_pages_exact().
3873 */
3874 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
3875 {
3876 unsigned int order = get_order(size);
3877 unsigned long addr;
3878
3879 addr = __get_free_pages(gfp_mask, order);
3880 return make_alloc_exact(addr, order, size);
3881 }
3882 EXPORT_SYMBOL(alloc_pages_exact);
3883
3884 /**
3885 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
3886 * pages on a node.
3887 * @nid: the preferred node ID where memory should be allocated
3888 * @size: the number of bytes to allocate
3889 * @gfp_mask: GFP flags for the allocation
3890 *
3891 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
3892 * back.
3893 */
3894 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
3895 {
3896 unsigned int order = get_order(size);
3897 struct page *p = alloc_pages_node(nid, gfp_mask, order);
3898 if (!p)
3899 return NULL;
3900 return make_alloc_exact((unsigned long)page_address(p), order, size);
3901 }
3902
3903 /**
3904 * free_pages_exact - release memory allocated via alloc_pages_exact()
3905 * @virt: the value returned by alloc_pages_exact.
3906 * @size: size of allocation, same value as passed to alloc_pages_exact().
3907 *
3908 * Release the memory allocated by a previous call to alloc_pages_exact.
3909 */
3910 void free_pages_exact(void *virt, size_t size)
3911 {
3912 unsigned long addr = (unsigned long)virt;
3913 unsigned long end = addr + PAGE_ALIGN(size);
3914
3915 while (addr < end) {
3916 free_page(addr);
3917 addr += PAGE_SIZE;
3918 }
3919 }
3920 EXPORT_SYMBOL(free_pages_exact);
3921
3922 /**
3923 * nr_free_zone_pages - count number of pages beyond high watermark
3924 * @offset: The zone index of the highest zone
3925 *
3926 * nr_free_zone_pages() counts the number of counts pages which are beyond the
3927 * high watermark within all zones at or below a given zone index. For each
3928 * zone, the number of pages is calculated as:
3929 * managed_pages - high_pages
3930 */
3931 static unsigned long nr_free_zone_pages(int offset)
3932 {
3933 struct zoneref *z;
3934 struct zone *zone;
3935
3936 /* Just pick one node, since fallback list is circular */
3937 unsigned long sum = 0;
3938
3939 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
3940
3941 for_each_zone_zonelist(zone, z, zonelist, offset) {
3942 unsigned long size = zone->managed_pages;
3943 unsigned long high = high_wmark_pages(zone);
3944 if (size > high)
3945 sum += size - high;
3946 }
3947
3948 return sum;
3949 }
3950
3951 /**
3952 * nr_free_buffer_pages - count number of pages beyond high watermark
3953 *
3954 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3955 * watermark within ZONE_DMA and ZONE_NORMAL.
3956 */
3957 unsigned long nr_free_buffer_pages(void)
3958 {
3959 return nr_free_zone_pages(gfp_zone(GFP_USER));
3960 }
3961 EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
3962
3963 /**
3964 * nr_free_pagecache_pages - count number of pages beyond high watermark
3965 *
3966 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3967 * high watermark within all zones.
3968 */
3969 unsigned long nr_free_pagecache_pages(void)
3970 {
3971 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
3972 }
3973
3974 static inline void show_node(struct zone *zone)
3975 {
3976 if (IS_ENABLED(CONFIG_NUMA))
3977 printk("Node %d ", zone_to_nid(zone));
3978 }
3979
3980 long si_mem_available(void)
3981 {
3982 long available;
3983 unsigned long pagecache;
3984 unsigned long wmark_low = 0;
3985 unsigned long pages[NR_LRU_LISTS];
3986 struct zone *zone;
3987 int lru;
3988
3989 for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++)
3990 pages[lru] = global_page_state(NR_LRU_BASE + lru);
3991
3992 for_each_zone(zone)
3993 wmark_low += zone->watermark[WMARK_LOW];
3994
3995 /*
3996 * Estimate the amount of memory available for userspace allocations,
3997 * without causing swapping.
3998 */
3999 available = global_page_state(NR_FREE_PAGES) - totalreserve_pages;
4000
4001 /*
4002 * Not all the page cache can be freed, otherwise the system will
4003 * start swapping. Assume at least half of the page cache, or the
4004 * low watermark worth of cache, needs to stay.
4005 */
4006 pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE];
4007 pagecache -= min(pagecache / 2, wmark_low);
4008 available += pagecache;
4009
4010 /*
4011 * Part of the reclaimable slab consists of items that are in use,
4012 * and cannot be freed. Cap this estimate at the low watermark.
4013 */
4014 available += global_page_state(NR_SLAB_RECLAIMABLE) -
4015 min(global_page_state(NR_SLAB_RECLAIMABLE) / 2, wmark_low);
4016
4017 if (available < 0)
4018 available = 0;
4019 return available;
4020 }
4021 EXPORT_SYMBOL_GPL(si_mem_available);
4022
4023 void si_meminfo(struct sysinfo *val)
4024 {
4025 val->totalram = totalram_pages;
4026 val->sharedram = global_page_state(NR_SHMEM);
4027 val->freeram = global_page_state(NR_FREE_PAGES);
4028 val->bufferram = nr_blockdev_pages();
4029 val->totalhigh = totalhigh_pages;
4030 val->freehigh = nr_free_highpages();
4031 val->mem_unit = PAGE_SIZE;
4032 }
4033
4034 EXPORT_SYMBOL(si_meminfo);
4035
4036 #ifdef CONFIG_NUMA
4037 void si_meminfo_node(struct sysinfo *val, int nid)
4038 {
4039 int zone_type; /* needs to be signed */
4040 unsigned long managed_pages = 0;
4041 unsigned long managed_highpages = 0;
4042 unsigned long free_highpages = 0;
4043 pg_data_t *pgdat = NODE_DATA(nid);
4044
4045 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
4046 managed_pages += pgdat->node_zones[zone_type].managed_pages;
4047 val->totalram = managed_pages;
4048 val->sharedram = node_page_state(nid, NR_SHMEM);
4049 val->freeram = node_page_state(nid, NR_FREE_PAGES);
4050 #ifdef CONFIG_HIGHMEM
4051 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
4052 struct zone *zone = &pgdat->node_zones[zone_type];
4053
4054 if (is_highmem(zone)) {
4055 managed_highpages += zone->managed_pages;
4056 free_highpages += zone_page_state(zone, NR_FREE_PAGES);
4057 }
4058 }
4059 val->totalhigh = managed_highpages;
4060 val->freehigh = free_highpages;
4061 #else
4062 val->totalhigh = managed_highpages;
4063 val->freehigh = free_highpages;
4064 #endif
4065 val->mem_unit = PAGE_SIZE;
4066 }
4067 #endif
4068
4069 /*
4070 * Determine whether the node should be displayed or not, depending on whether
4071 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
4072 */
4073 bool skip_free_areas_node(unsigned int flags, int nid)
4074 {
4075 bool ret = false;
4076 unsigned int cpuset_mems_cookie;
4077
4078 if (!(flags & SHOW_MEM_FILTER_NODES))
4079 goto out;
4080
4081 do {
4082 cpuset_mems_cookie = read_mems_allowed_begin();
4083 ret = !node_isset(nid, cpuset_current_mems_allowed);
4084 } while (read_mems_allowed_retry(cpuset_mems_cookie));
4085 out:
4086 return ret;
4087 }
4088
4089 #define K(x) ((x) << (PAGE_SHIFT-10))
4090
4091 static void show_migration_types(unsigned char type)
4092 {
4093 static const char types[MIGRATE_TYPES] = {
4094 [MIGRATE_UNMOVABLE] = 'U',
4095 [MIGRATE_MOVABLE] = 'M',
4096 [MIGRATE_RECLAIMABLE] = 'E',
4097 [MIGRATE_HIGHATOMIC] = 'H',
4098 #ifdef CONFIG_CMA
4099 [MIGRATE_CMA] = 'C',
4100 #endif
4101 #ifdef CONFIG_MEMORY_ISOLATION
4102 [MIGRATE_ISOLATE] = 'I',
4103 #endif
4104 };
4105 char tmp[MIGRATE_TYPES + 1];
4106 char *p = tmp;
4107 int i;
4108
4109 for (i = 0; i < MIGRATE_TYPES; i++) {
4110 if (type & (1 << i))
4111 *p++ = types[i];
4112 }
4113
4114 *p = '\0';
4115 printk("(%s) ", tmp);
4116 }
4117
4118 /*
4119 * Show free area list (used inside shift_scroll-lock stuff)
4120 * We also calculate the percentage fragmentation. We do this by counting the
4121 * memory on each free list with the exception of the first item on the list.
4122 *
4123 * Bits in @filter:
4124 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
4125 * cpuset.
4126 */
4127 void show_free_areas(unsigned int filter)
4128 {
4129 unsigned long free_pcp = 0;
4130 int cpu;
4131 struct zone *zone;
4132
4133 for_each_populated_zone(zone) {
4134 if (skip_free_areas_node(filter, zone_to_nid(zone)))
4135 continue;
4136
4137 for_each_online_cpu(cpu)
4138 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
4139 }
4140
4141 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
4142 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
4143 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
4144 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
4145 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
4146 " free:%lu free_pcp:%lu free_cma:%lu\n",
4147 global_page_state(NR_ACTIVE_ANON),
4148 global_page_state(NR_INACTIVE_ANON),
4149 global_page_state(NR_ISOLATED_ANON),
4150 global_page_state(NR_ACTIVE_FILE),
4151 global_page_state(NR_INACTIVE_FILE),
4152 global_page_state(NR_ISOLATED_FILE),
4153 global_page_state(NR_UNEVICTABLE),
4154 global_page_state(NR_FILE_DIRTY),
4155 global_page_state(NR_WRITEBACK),
4156 global_page_state(NR_UNSTABLE_NFS),
4157 global_page_state(NR_SLAB_RECLAIMABLE),
4158 global_page_state(NR_SLAB_UNRECLAIMABLE),
4159 global_page_state(NR_FILE_MAPPED),
4160 global_page_state(NR_SHMEM),
4161 global_page_state(NR_PAGETABLE),
4162 global_page_state(NR_BOUNCE),
4163 global_page_state(NR_FREE_PAGES),
4164 free_pcp,
4165 global_page_state(NR_FREE_CMA_PAGES));
4166
4167 for_each_populated_zone(zone) {
4168 int i;
4169
4170 if (skip_free_areas_node(filter, zone_to_nid(zone)))
4171 continue;
4172
4173 free_pcp = 0;
4174 for_each_online_cpu(cpu)
4175 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
4176
4177 show_node(zone);
4178 printk("%s"
4179 " free:%lukB"
4180 " min:%lukB"
4181 " low:%lukB"
4182 " high:%lukB"
4183 " active_anon:%lukB"
4184 " inactive_anon:%lukB"
4185 " active_file:%lukB"
4186 " inactive_file:%lukB"
4187 " unevictable:%lukB"
4188 " isolated(anon):%lukB"
4189 " isolated(file):%lukB"
4190 " present:%lukB"
4191 " managed:%lukB"
4192 " mlocked:%lukB"
4193 " dirty:%lukB"
4194 " writeback:%lukB"
4195 " mapped:%lukB"
4196 " shmem:%lukB"
4197 " slab_reclaimable:%lukB"
4198 " slab_unreclaimable:%lukB"
4199 " kernel_stack:%lukB"
4200 " pagetables:%lukB"
4201 " unstable:%lukB"
4202 " bounce:%lukB"
4203 " free_pcp:%lukB"
4204 " local_pcp:%ukB"
4205 " free_cma:%lukB"
4206 " writeback_tmp:%lukB"
4207 " pages_scanned:%lu"
4208 " all_unreclaimable? %s"
4209 "\n",
4210 zone->name,
4211 K(zone_page_state(zone, NR_FREE_PAGES)),
4212 K(min_wmark_pages(zone)),
4213 K(low_wmark_pages(zone)),
4214 K(high_wmark_pages(zone)),
4215 K(zone_page_state(zone, NR_ACTIVE_ANON)),
4216 K(zone_page_state(zone, NR_INACTIVE_ANON)),
4217 K(zone_page_state(zone, NR_ACTIVE_FILE)),
4218 K(zone_page_state(zone, NR_INACTIVE_FILE)),
4219 K(zone_page_state(zone, NR_UNEVICTABLE)),
4220 K(zone_page_state(zone, NR_ISOLATED_ANON)),
4221 K(zone_page_state(zone, NR_ISOLATED_FILE)),
4222 K(zone->present_pages),
4223 K(zone->managed_pages),
4224 K(zone_page_state(zone, NR_MLOCK)),
4225 K(zone_page_state(zone, NR_FILE_DIRTY)),
4226 K(zone_page_state(zone, NR_WRITEBACK)),
4227 K(zone_page_state(zone, NR_FILE_MAPPED)),
4228 K(zone_page_state(zone, NR_SHMEM)),
4229 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
4230 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
4231 zone_page_state(zone, NR_KERNEL_STACK) *
4232 THREAD_SIZE / 1024,
4233 K(zone_page_state(zone, NR_PAGETABLE)),
4234 K(zone_page_state(zone, NR_UNSTABLE_NFS)),
4235 K(zone_page_state(zone, NR_BOUNCE)),
4236 K(free_pcp),
4237 K(this_cpu_read(zone->pageset->pcp.count)),
4238 K(zone_page_state(zone, NR_FREE_CMA_PAGES)),
4239 K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
4240 K(zone_page_state(zone, NR_PAGES_SCANNED)),
4241 (!zone_reclaimable(zone) ? "yes" : "no")
4242 );
4243 printk("lowmem_reserve[]:");
4244 for (i = 0; i < MAX_NR_ZONES; i++)
4245 printk(" %ld", zone->lowmem_reserve[i]);
4246 printk("\n");
4247 }
4248
4249 for_each_populated_zone(zone) {
4250 unsigned int order;
4251 unsigned long nr[MAX_ORDER], flags, total = 0;
4252 unsigned char types[MAX_ORDER];
4253
4254 if (skip_free_areas_node(filter, zone_to_nid(zone)))
4255 continue;
4256 show_node(zone);
4257 printk("%s: ", zone->name);
4258
4259 spin_lock_irqsave(&zone->lock, flags);
4260 for (order = 0; order < MAX_ORDER; order++) {
4261 struct free_area *area = &zone->free_area[order];
4262 int type;
4263
4264 nr[order] = area->nr_free;
4265 total += nr[order] << order;
4266
4267 types[order] = 0;
4268 for (type = 0; type < MIGRATE_TYPES; type++) {
4269 if (!list_empty(&area->free_list[type]))
4270 types[order] |= 1 << type;
4271 }
4272 }
4273 spin_unlock_irqrestore(&zone->lock, flags);
4274 for (order = 0; order < MAX_ORDER; order++) {
4275 printk("%lu*%lukB ", nr[order], K(1UL) << order);
4276 if (nr[order])
4277 show_migration_types(types[order]);
4278 }
4279 printk("= %lukB\n", K(total));
4280 }
4281
4282 hugetlb_show_meminfo();
4283
4284 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
4285
4286 show_swap_cache_info();
4287 }
4288
4289 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
4290 {
4291 zoneref->zone = zone;
4292 zoneref->zone_idx = zone_idx(zone);
4293 }
4294
4295 /*
4296 * Builds allocation fallback zone lists.
4297 *
4298 * Add all populated zones of a node to the zonelist.
4299 */
4300 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
4301 int nr_zones)
4302 {
4303 struct zone *zone;
4304 enum zone_type zone_type = MAX_NR_ZONES;
4305
4306 do {
4307 zone_type--;
4308 zone = pgdat->node_zones + zone_type;
4309 if (populated_zone(zone)) {
4310 zoneref_set_zone(zone,
4311 &zonelist->_zonerefs[nr_zones++]);
4312 check_highest_zone(zone_type);
4313 }
4314 } while (zone_type);
4315
4316 return nr_zones;
4317 }
4318
4319
4320 /*
4321 * zonelist_order:
4322 * 0 = automatic detection of better ordering.
4323 * 1 = order by ([node] distance, -zonetype)
4324 * 2 = order by (-zonetype, [node] distance)
4325 *
4326 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
4327 * the same zonelist. So only NUMA can configure this param.
4328 */
4329 #define ZONELIST_ORDER_DEFAULT 0
4330 #define ZONELIST_ORDER_NODE 1
4331 #define ZONELIST_ORDER_ZONE 2
4332
4333 /* zonelist order in the kernel.
4334 * set_zonelist_order() will set this to NODE or ZONE.
4335 */
4336 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
4337 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
4338
4339
4340 #ifdef CONFIG_NUMA
4341 /* The value user specified ....changed by config */
4342 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
4343 /* string for sysctl */
4344 #define NUMA_ZONELIST_ORDER_LEN 16
4345 char numa_zonelist_order[16] = "default";
4346
4347 /*
4348 * interface for configure zonelist ordering.
4349 * command line option "numa_zonelist_order"
4350 * = "[dD]efault - default, automatic configuration.
4351 * = "[nN]ode - order by node locality, then by zone within node
4352 * = "[zZ]one - order by zone, then by locality within zone
4353 */
4354
4355 static int __parse_numa_zonelist_order(char *s)
4356 {
4357 if (*s == 'd' || *s == 'D') {
4358 user_zonelist_order = ZONELIST_ORDER_DEFAULT;
4359 } else if (*s == 'n' || *s == 'N') {
4360 user_zonelist_order = ZONELIST_ORDER_NODE;
4361 } else if (*s == 'z' || *s == 'Z') {
4362 user_zonelist_order = ZONELIST_ORDER_ZONE;
4363 } else {
4364 pr_warn("Ignoring invalid numa_zonelist_order value: %s\n", s);
4365 return -EINVAL;
4366 }
4367 return 0;
4368 }
4369
4370 static __init int setup_numa_zonelist_order(char *s)
4371 {
4372 int ret;
4373
4374 if (!s)
4375 return 0;
4376
4377 ret = __parse_numa_zonelist_order(s);
4378 if (ret == 0)
4379 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
4380
4381 return ret;
4382 }
4383 early_param("numa_zonelist_order", setup_numa_zonelist_order);
4384
4385 /*
4386 * sysctl handler for numa_zonelist_order
4387 */
4388 int numa_zonelist_order_handler(struct ctl_table *table, int write,
4389 void __user *buffer, size_t *length,
4390 loff_t *ppos)
4391 {
4392 char saved_string[NUMA_ZONELIST_ORDER_LEN];
4393 int ret;
4394 static DEFINE_MUTEX(zl_order_mutex);
4395
4396 mutex_lock(&zl_order_mutex);
4397 if (write) {
4398 if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
4399 ret = -EINVAL;
4400 goto out;
4401 }
4402 strcpy(saved_string, (char *)table->data);
4403 }
4404 ret = proc_dostring(table, write, buffer, length, ppos);
4405 if (ret)
4406 goto out;
4407 if (write) {
4408 int oldval = user_zonelist_order;
4409
4410 ret = __parse_numa_zonelist_order((char *)table->data);
4411 if (ret) {
4412 /*
4413 * bogus value. restore saved string
4414 */
4415 strncpy((char *)table->data, saved_string,
4416 NUMA_ZONELIST_ORDER_LEN);
4417 user_zonelist_order = oldval;
4418 } else if (oldval != user_zonelist_order) {
4419 mutex_lock(&zonelists_mutex);
4420 build_all_zonelists(NULL, NULL);
4421 mutex_unlock(&zonelists_mutex);
4422 }
4423 }
4424 out:
4425 mutex_unlock(&zl_order_mutex);
4426 return ret;
4427 }
4428
4429
4430 #define MAX_NODE_LOAD (nr_online_nodes)
4431 static int node_load[MAX_NUMNODES];
4432
4433 /**
4434 * find_next_best_node - find the next node that should appear in a given node's fallback list
4435 * @node: node whose fallback list we're appending
4436 * @used_node_mask: nodemask_t of already used nodes
4437 *
4438 * We use a number of factors to determine which is the next node that should
4439 * appear on a given node's fallback list. The node should not have appeared
4440 * already in @node's fallback list, and it should be the next closest node
4441 * according to the distance array (which contains arbitrary distance values
4442 * from each node to each node in the system), and should also prefer nodes
4443 * with no CPUs, since presumably they'll have very little allocation pressure
4444 * on them otherwise.
4445 * It returns -1 if no node is found.
4446 */
4447 static int find_next_best_node(int node, nodemask_t *used_node_mask)
4448 {
4449 int n, val;
4450 int min_val = INT_MAX;
4451 int best_node = NUMA_NO_NODE;
4452 const struct cpumask *tmp = cpumask_of_node(0);
4453
4454 /* Use the local node if we haven't already */
4455 if (!node_isset(node, *used_node_mask)) {
4456 node_set(node, *used_node_mask);
4457 return node;
4458 }
4459
4460 for_each_node_state(n, N_MEMORY) {
4461
4462 /* Don't want a node to appear more than once */
4463 if (node_isset(n, *used_node_mask))
4464 continue;
4465
4466 /* Use the distance array to find the distance */
4467 val = node_distance(node, n);
4468
4469 /* Penalize nodes under us ("prefer the next node") */
4470 val += (n < node);
4471
4472 /* Give preference to headless and unused nodes */
4473 tmp = cpumask_of_node(n);
4474 if (!cpumask_empty(tmp))
4475 val += PENALTY_FOR_NODE_WITH_CPUS;
4476
4477 /* Slight preference for less loaded node */
4478 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
4479 val += node_load[n];
4480
4481 if (val < min_val) {
4482 min_val = val;
4483 best_node = n;
4484 }
4485 }
4486
4487 if (best_node >= 0)
4488 node_set(best_node, *used_node_mask);
4489
4490 return best_node;
4491 }
4492
4493
4494 /*
4495 * Build zonelists ordered by node and zones within node.
4496 * This results in maximum locality--normal zone overflows into local
4497 * DMA zone, if any--but risks exhausting DMA zone.
4498 */
4499 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
4500 {
4501 int j;
4502 struct zonelist *zonelist;
4503
4504 zonelist = &pgdat->node_zonelists[0];
4505 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
4506 ;
4507 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4508 zonelist->_zonerefs[j].zone = NULL;
4509 zonelist->_zonerefs[j].zone_idx = 0;
4510 }
4511
4512 /*
4513 * Build gfp_thisnode zonelists
4514 */
4515 static void build_thisnode_zonelists(pg_data_t *pgdat)
4516 {
4517 int j;
4518 struct zonelist *zonelist;
4519
4520 zonelist = &pgdat->node_zonelists[1];
4521 j = build_zonelists_node(pgdat, zonelist, 0);
4522 zonelist->_zonerefs[j].zone = NULL;
4523 zonelist->_zonerefs[j].zone_idx = 0;
4524 }
4525
4526 /*
4527 * Build zonelists ordered by zone and nodes within zones.
4528 * This results in conserving DMA zone[s] until all Normal memory is
4529 * exhausted, but results in overflowing to remote node while memory
4530 * may still exist in local DMA zone.
4531 */
4532 static int node_order[MAX_NUMNODES];
4533
4534 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
4535 {
4536 int pos, j, node;
4537 int zone_type; /* needs to be signed */
4538 struct zone *z;
4539 struct zonelist *zonelist;
4540
4541 zonelist = &pgdat->node_zonelists[0];
4542 pos = 0;
4543 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
4544 for (j = 0; j < nr_nodes; j++) {
4545 node = node_order[j];
4546 z = &NODE_DATA(node)->node_zones[zone_type];
4547 if (populated_zone(z)) {
4548 zoneref_set_zone(z,
4549 &zonelist->_zonerefs[pos++]);
4550 check_highest_zone(zone_type);
4551 }
4552 }
4553 }
4554 zonelist->_zonerefs[pos].zone = NULL;
4555 zonelist->_zonerefs[pos].zone_idx = 0;
4556 }
4557
4558 #if defined(CONFIG_64BIT)
4559 /*
4560 * Devices that require DMA32/DMA are relatively rare and do not justify a
4561 * penalty to every machine in case the specialised case applies. Default
4562 * to Node-ordering on 64-bit NUMA machines
4563 */
4564 static int default_zonelist_order(void)
4565 {
4566 return ZONELIST_ORDER_NODE;
4567 }
4568 #else
4569 /*
4570 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4571 * by the kernel. If processes running on node 0 deplete the low memory zone
4572 * then reclaim will occur more frequency increasing stalls and potentially
4573 * be easier to OOM if a large percentage of the zone is under writeback or
4574 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4575 * Hence, default to zone ordering on 32-bit.
4576 */
4577 static int default_zonelist_order(void)
4578 {
4579 return ZONELIST_ORDER_ZONE;
4580 }
4581 #endif /* CONFIG_64BIT */
4582
4583 static void set_zonelist_order(void)
4584 {
4585 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
4586 current_zonelist_order = default_zonelist_order();
4587 else
4588 current_zonelist_order = user_zonelist_order;
4589 }
4590
4591 static void build_zonelists(pg_data_t *pgdat)
4592 {
4593 int i, node, load;
4594 nodemask_t used_mask;
4595 int local_node, prev_node;
4596 struct zonelist *zonelist;
4597 unsigned int order = current_zonelist_order;
4598
4599 /* initialize zonelists */
4600 for (i = 0; i < MAX_ZONELISTS; i++) {
4601 zonelist = pgdat->node_zonelists + i;
4602 zonelist->_zonerefs[0].zone = NULL;
4603 zonelist->_zonerefs[0].zone_idx = 0;
4604 }
4605
4606 /* NUMA-aware ordering of nodes */
4607 local_node = pgdat->node_id;
4608 load = nr_online_nodes;
4609 prev_node = local_node;
4610 nodes_clear(used_mask);
4611
4612 memset(node_order, 0, sizeof(node_order));
4613 i = 0;
4614
4615 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
4616 /*
4617 * We don't want to pressure a particular node.
4618 * So adding penalty to the first node in same
4619 * distance group to make it round-robin.
4620 */
4621 if (node_distance(local_node, node) !=
4622 node_distance(local_node, prev_node))
4623 node_load[node] = load;
4624
4625 prev_node = node;
4626 load--;
4627 if (order == ZONELIST_ORDER_NODE)
4628 build_zonelists_in_node_order(pgdat, node);
4629 else
4630 node_order[i++] = node; /* remember order */
4631 }
4632
4633 if (order == ZONELIST_ORDER_ZONE) {
4634 /* calculate node order -- i.e., DMA last! */
4635 build_zonelists_in_zone_order(pgdat, i);
4636 }
4637
4638 build_thisnode_zonelists(pgdat);
4639 }
4640
4641 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4642 /*
4643 * Return node id of node used for "local" allocations.
4644 * I.e., first node id of first zone in arg node's generic zonelist.
4645 * Used for initializing percpu 'numa_mem', which is used primarily
4646 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4647 */
4648 int local_memory_node(int node)
4649 {
4650 struct zoneref *z;
4651
4652 z = first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
4653 gfp_zone(GFP_KERNEL),
4654 NULL);
4655 return z->zone->node;
4656 }
4657 #endif
4658
4659 #else /* CONFIG_NUMA */
4660
4661 static void set_zonelist_order(void)
4662 {
4663 current_zonelist_order = ZONELIST_ORDER_ZONE;
4664 }
4665
4666 static void build_zonelists(pg_data_t *pgdat)
4667 {
4668 int node, local_node;
4669 enum zone_type j;
4670 struct zonelist *zonelist;
4671
4672 local_node = pgdat->node_id;
4673
4674 zonelist = &pgdat->node_zonelists[0];
4675 j = build_zonelists_node(pgdat, zonelist, 0);
4676
4677 /*
4678 * Now we build the zonelist so that it contains the zones
4679 * of all the other nodes.
4680 * We don't want to pressure a particular node, so when
4681 * building the zones for node N, we make sure that the
4682 * zones coming right after the local ones are those from
4683 * node N+1 (modulo N)
4684 */
4685 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
4686 if (!node_online(node))
4687 continue;
4688 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4689 }
4690 for (node = 0; node < local_node; node++) {
4691 if (!node_online(node))
4692 continue;
4693 j = build_zonelists_node(NODE_DATA(node), zonelist, j);
4694 }
4695
4696 zonelist->_zonerefs[j].zone = NULL;
4697 zonelist->_zonerefs[j].zone_idx = 0;
4698 }
4699
4700 #endif /* CONFIG_NUMA */
4701
4702 /*
4703 * Boot pageset table. One per cpu which is going to be used for all
4704 * zones and all nodes. The parameters will be set in such a way
4705 * that an item put on a list will immediately be handed over to
4706 * the buddy list. This is safe since pageset manipulation is done
4707 * with interrupts disabled.
4708 *
4709 * The boot_pagesets must be kept even after bootup is complete for
4710 * unused processors and/or zones. They do play a role for bootstrapping
4711 * hotplugged processors.
4712 *
4713 * zoneinfo_show() and maybe other functions do
4714 * not check if the processor is online before following the pageset pointer.
4715 * Other parts of the kernel may not check if the zone is available.
4716 */
4717 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
4718 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
4719 static void setup_zone_pageset(struct zone *zone);
4720
4721 /*
4722 * Global mutex to protect against size modification of zonelists
4723 * as well as to serialize pageset setup for the new populated zone.
4724 */
4725 DEFINE_MUTEX(zonelists_mutex);
4726
4727 /* return values int ....just for stop_machine() */
4728 static int __build_all_zonelists(void *data)
4729 {
4730 int nid;
4731 int cpu;
4732 pg_data_t *self = data;
4733
4734 #ifdef CONFIG_NUMA
4735 memset(node_load, 0, sizeof(node_load));
4736 #endif
4737
4738 if (self && !node_online(self->node_id)) {
4739 build_zonelists(self);
4740 }
4741
4742 for_each_online_node(nid) {
4743 pg_data_t *pgdat = NODE_DATA(nid);
4744
4745 build_zonelists(pgdat);
4746 }
4747
4748 /*
4749 * Initialize the boot_pagesets that are going to be used
4750 * for bootstrapping processors. The real pagesets for
4751 * each zone will be allocated later when the per cpu
4752 * allocator is available.
4753 *
4754 * boot_pagesets are used also for bootstrapping offline
4755 * cpus if the system is already booted because the pagesets
4756 * are needed to initialize allocators on a specific cpu too.
4757 * F.e. the percpu allocator needs the page allocator which
4758 * needs the percpu allocator in order to allocate its pagesets
4759 * (a chicken-egg dilemma).
4760 */
4761 for_each_possible_cpu(cpu) {
4762 setup_pageset(&per_cpu(boot_pageset, cpu), 0);
4763
4764 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4765 /*
4766 * We now know the "local memory node" for each node--
4767 * i.e., the node of the first zone in the generic zonelist.
4768 * Set up numa_mem percpu variable for on-line cpus. During
4769 * boot, only the boot cpu should be on-line; we'll init the
4770 * secondary cpus' numa_mem as they come on-line. During
4771 * node/memory hotplug, we'll fixup all on-line cpus.
4772 */
4773 if (cpu_online(cpu))
4774 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
4775 #endif
4776 }
4777
4778 return 0;
4779 }
4780
4781 static noinline void __init
4782 build_all_zonelists_init(void)
4783 {
4784 __build_all_zonelists(NULL);
4785 mminit_verify_zonelist();
4786 cpuset_init_current_mems_allowed();
4787 }
4788
4789 /*
4790 * Called with zonelists_mutex held always
4791 * unless system_state == SYSTEM_BOOTING.
4792 *
4793 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4794 * [we're only called with non-NULL zone through __meminit paths] and
4795 * (2) call of __init annotated helper build_all_zonelists_init
4796 * [protected by SYSTEM_BOOTING].
4797 */
4798 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
4799 {
4800 set_zonelist_order();
4801
4802 if (system_state == SYSTEM_BOOTING) {
4803 build_all_zonelists_init();
4804 } else {
4805 #ifdef CONFIG_MEMORY_HOTPLUG
4806 if (zone)
4807 setup_zone_pageset(zone);
4808 #endif
4809 /* we have to stop all cpus to guarantee there is no user
4810 of zonelist */
4811 stop_machine(__build_all_zonelists, pgdat, NULL);
4812 /* cpuset refresh routine should be here */
4813 }
4814 vm_total_pages = nr_free_pagecache_pages();
4815 /*
4816 * Disable grouping by mobility if the number of pages in the
4817 * system is too low to allow the mechanism to work. It would be
4818 * more accurate, but expensive to check per-zone. This check is
4819 * made on memory-hotadd so a system can start with mobility
4820 * disabled and enable it later
4821 */
4822 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
4823 page_group_by_mobility_disabled = 1;
4824 else
4825 page_group_by_mobility_disabled = 0;
4826
4827 pr_info("Built %i zonelists in %s order, mobility grouping %s. Total pages: %ld\n",
4828 nr_online_nodes,
4829 zonelist_order_name[current_zonelist_order],
4830 page_group_by_mobility_disabled ? "off" : "on",
4831 vm_total_pages);
4832 #ifdef CONFIG_NUMA
4833 pr_info("Policy zone: %s\n", zone_names[policy_zone]);
4834 #endif
4835 }
4836
4837 /*
4838 * Helper functions to size the waitqueue hash table.
4839 * Essentially these want to choose hash table sizes sufficiently
4840 * large so that collisions trying to wait on pages are rare.
4841 * But in fact, the number of active page waitqueues on typical
4842 * systems is ridiculously low, less than 200. So this is even
4843 * conservative, even though it seems large.
4844 *
4845 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
4846 * waitqueues, i.e. the size of the waitq table given the number of pages.
4847 */
4848 #define PAGES_PER_WAITQUEUE 256
4849
4850 #ifndef CONFIG_MEMORY_HOTPLUG
4851 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
4852 {
4853 unsigned long size = 1;
4854
4855 pages /= PAGES_PER_WAITQUEUE;
4856
4857 while (size < pages)
4858 size <<= 1;
4859
4860 /*
4861 * Once we have dozens or even hundreds of threads sleeping
4862 * on IO we've got bigger problems than wait queue collision.
4863 * Limit the size of the wait table to a reasonable size.
4864 */
4865 size = min(size, 4096UL);
4866
4867 return max(size, 4UL);
4868 }
4869 #else
4870 /*
4871 * A zone's size might be changed by hot-add, so it is not possible to determine
4872 * a suitable size for its wait_table. So we use the maximum size now.
4873 *
4874 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
4875 *
4876 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
4877 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
4878 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
4879 *
4880 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
4881 * or more by the traditional way. (See above). It equals:
4882 *
4883 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
4884 * ia64(16K page size) : = ( 8G + 4M)byte.
4885 * powerpc (64K page size) : = (32G +16M)byte.
4886 */
4887 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
4888 {
4889 return 4096UL;
4890 }
4891 #endif
4892
4893 /*
4894 * This is an integer logarithm so that shifts can be used later
4895 * to extract the more random high bits from the multiplicative
4896 * hash function before the remainder is taken.
4897 */
4898 static inline unsigned long wait_table_bits(unsigned long size)
4899 {
4900 return ffz(~size);
4901 }
4902
4903 /*
4904 * Initially all pages are reserved - free ones are freed
4905 * up by free_all_bootmem() once the early boot process is
4906 * done. Non-atomic initialization, single-pass.
4907 */
4908 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
4909 unsigned long start_pfn, enum memmap_context context)
4910 {
4911 struct vmem_altmap *altmap = to_vmem_altmap(__pfn_to_phys(start_pfn));
4912 unsigned long end_pfn = start_pfn + size;
4913 pg_data_t *pgdat = NODE_DATA(nid);
4914 unsigned long pfn;
4915 unsigned long nr_initialised = 0;
4916 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4917 struct memblock_region *r = NULL, *tmp;
4918 #endif
4919
4920 if (highest_memmap_pfn < end_pfn - 1)
4921 highest_memmap_pfn = end_pfn - 1;
4922
4923 /*
4924 * Honor reservation requested by the driver for this ZONE_DEVICE
4925 * memory
4926 */
4927 if (altmap && start_pfn == altmap->base_pfn)
4928 start_pfn += altmap->reserve;
4929
4930 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
4931 /*
4932 * There can be holes in boot-time mem_map[]s handed to this
4933 * function. They do not exist on hotplugged memory.
4934 */
4935 if (context != MEMMAP_EARLY)
4936 goto not_early;
4937
4938 if (!early_pfn_valid(pfn))
4939 continue;
4940 if (!early_pfn_in_nid(pfn, nid))
4941 continue;
4942 if (!update_defer_init(pgdat, pfn, end_pfn, &nr_initialised))
4943 break;
4944
4945 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4946 /*
4947 * If not mirrored_kernelcore and ZONE_MOVABLE exists, range
4948 * from zone_movable_pfn[nid] to end of each node should be
4949 * ZONE_MOVABLE not ZONE_NORMAL. skip it.
4950 */
4951 if (!mirrored_kernelcore && zone_movable_pfn[nid])
4952 if (zone == ZONE_NORMAL && pfn >= zone_movable_pfn[nid])
4953 continue;
4954
4955 /*
4956 * Check given memblock attribute by firmware which can affect
4957 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
4958 * mirrored, it's an overlapped memmap init. skip it.
4959 */
4960 if (mirrored_kernelcore && zone == ZONE_MOVABLE) {
4961 if (!r || pfn >= memblock_region_memory_end_pfn(r)) {
4962 for_each_memblock(memory, tmp)
4963 if (pfn < memblock_region_memory_end_pfn(tmp))
4964 break;
4965 r = tmp;
4966 }
4967 if (pfn >= memblock_region_memory_base_pfn(r) &&
4968 memblock_is_mirror(r)) {
4969 /* already initialized as NORMAL */
4970 pfn = memblock_region_memory_end_pfn(r);
4971 continue;
4972 }
4973 }
4974 #endif
4975
4976 not_early:
4977 /*
4978 * Mark the block movable so that blocks are reserved for
4979 * movable at startup. This will force kernel allocations
4980 * to reserve their blocks rather than leaking throughout
4981 * the address space during boot when many long-lived
4982 * kernel allocations are made.
4983 *
4984 * bitmap is created for zone's valid pfn range. but memmap
4985 * can be created for invalid pages (for alignment)
4986 * check here not to call set_pageblock_migratetype() against
4987 * pfn out of zone.
4988 */
4989 if (!(pfn & (pageblock_nr_pages - 1))) {
4990 struct page *page = pfn_to_page(pfn);
4991
4992 __init_single_page(page, pfn, zone, nid);
4993 set_pageblock_migratetype(page, MIGRATE_MOVABLE);
4994 } else {
4995 __init_single_pfn(pfn, zone, nid);
4996 }
4997 }
4998 }
4999
5000 static void __meminit zone_init_free_lists(struct zone *zone)
5001 {
5002 unsigned int order, t;
5003 for_each_migratetype_order(order, t) {
5004 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
5005 zone->free_area[order].nr_free = 0;
5006 }
5007 }
5008
5009 #ifndef __HAVE_ARCH_MEMMAP_INIT
5010 #define memmap_init(size, nid, zone, start_pfn) \
5011 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
5012 #endif
5013
5014 static int zone_batchsize(struct zone *zone)
5015 {
5016 #ifdef CONFIG_MMU
5017 int batch;
5018
5019 /*
5020 * The per-cpu-pages pools are set to around 1000th of the
5021 * size of the zone. But no more than 1/2 of a meg.
5022 *
5023 * OK, so we don't know how big the cache is. So guess.
5024 */
5025 batch = zone->managed_pages / 1024;
5026 if (batch * PAGE_SIZE > 512 * 1024)
5027 batch = (512 * 1024) / PAGE_SIZE;
5028 batch /= 4; /* We effectively *= 4 below */
5029 if (batch < 1)
5030 batch = 1;
5031
5032 /*
5033 * Clamp the batch to a 2^n - 1 value. Having a power
5034 * of 2 value was found to be more likely to have
5035 * suboptimal cache aliasing properties in some cases.
5036 *
5037 * For example if 2 tasks are alternately allocating
5038 * batches of pages, one task can end up with a lot
5039 * of pages of one half of the possible page colors
5040 * and the other with pages of the other colors.
5041 */
5042 batch = rounddown_pow_of_two(batch + batch/2) - 1;
5043
5044 return batch;
5045
5046 #else
5047 /* The deferral and batching of frees should be suppressed under NOMMU
5048 * conditions.
5049 *
5050 * The problem is that NOMMU needs to be able to allocate large chunks
5051 * of contiguous memory as there's no hardware page translation to
5052 * assemble apparent contiguous memory from discontiguous pages.
5053 *
5054 * Queueing large contiguous runs of pages for batching, however,
5055 * causes the pages to actually be freed in smaller chunks. As there
5056 * can be a significant delay between the individual batches being
5057 * recycled, this leads to the once large chunks of space being
5058 * fragmented and becoming unavailable for high-order allocations.
5059 */
5060 return 0;
5061 #endif
5062 }
5063
5064 /*
5065 * pcp->high and pcp->batch values are related and dependent on one another:
5066 * ->batch must never be higher then ->high.
5067 * The following function updates them in a safe manner without read side
5068 * locking.
5069 *
5070 * Any new users of pcp->batch and pcp->high should ensure they can cope with
5071 * those fields changing asynchronously (acording the the above rule).
5072 *
5073 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
5074 * outside of boot time (or some other assurance that no concurrent updaters
5075 * exist).
5076 */
5077 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high,
5078 unsigned long batch)
5079 {
5080 /* start with a fail safe value for batch */
5081 pcp->batch = 1;
5082 smp_wmb();
5083
5084 /* Update high, then batch, in order */
5085 pcp->high = high;
5086 smp_wmb();
5087
5088 pcp->batch = batch;
5089 }
5090
5091 /* a companion to pageset_set_high() */
5092 static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch)
5093 {
5094 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch));
5095 }
5096
5097 static void pageset_init(struct per_cpu_pageset *p)
5098 {
5099 struct per_cpu_pages *pcp;
5100 int migratetype;
5101
5102 memset(p, 0, sizeof(*p));
5103
5104 pcp = &p->pcp;
5105 pcp->count = 0;
5106 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
5107 INIT_LIST_HEAD(&pcp->lists[migratetype]);
5108 }
5109
5110 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
5111 {
5112 pageset_init(p);
5113 pageset_set_batch(p, batch);
5114 }
5115
5116 /*
5117 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
5118 * to the value high for the pageset p.
5119 */
5120 static void pageset_set_high(struct per_cpu_pageset *p,
5121 unsigned long high)
5122 {
5123 unsigned long batch = max(1UL, high / 4);
5124 if ((high / 4) > (PAGE_SHIFT * 8))
5125 batch = PAGE_SHIFT * 8;
5126
5127 pageset_update(&p->pcp, high, batch);
5128 }
5129
5130 static void pageset_set_high_and_batch(struct zone *zone,
5131 struct per_cpu_pageset *pcp)
5132 {
5133 if (percpu_pagelist_fraction)
5134 pageset_set_high(pcp,
5135 (zone->managed_pages /
5136 percpu_pagelist_fraction));
5137 else
5138 pageset_set_batch(pcp, zone_batchsize(zone));
5139 }
5140
5141 static void __meminit zone_pageset_init(struct zone *zone, int cpu)
5142 {
5143 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
5144
5145 pageset_init(pcp);
5146 pageset_set_high_and_batch(zone, pcp);
5147 }
5148
5149 static void __meminit setup_zone_pageset(struct zone *zone)
5150 {
5151 int cpu;
5152 zone->pageset = alloc_percpu(struct per_cpu_pageset);
5153 for_each_possible_cpu(cpu)
5154 zone_pageset_init(zone, cpu);
5155 }
5156
5157 /*
5158 * Allocate per cpu pagesets and initialize them.
5159 * Before this call only boot pagesets were available.
5160 */
5161 void __init setup_per_cpu_pageset(void)
5162 {
5163 struct zone *zone;
5164
5165 for_each_populated_zone(zone)
5166 setup_zone_pageset(zone);
5167 }
5168
5169 static noinline __init_refok
5170 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
5171 {
5172 int i;
5173 size_t alloc_size;
5174
5175 /*
5176 * The per-page waitqueue mechanism uses hashed waitqueues
5177 * per zone.
5178 */
5179 zone->wait_table_hash_nr_entries =
5180 wait_table_hash_nr_entries(zone_size_pages);
5181 zone->wait_table_bits =
5182 wait_table_bits(zone->wait_table_hash_nr_entries);
5183 alloc_size = zone->wait_table_hash_nr_entries
5184 * sizeof(wait_queue_head_t);
5185
5186 if (!slab_is_available()) {
5187 zone->wait_table = (wait_queue_head_t *)
5188 memblock_virt_alloc_node_nopanic(
5189 alloc_size, zone->zone_pgdat->node_id);
5190 } else {
5191 /*
5192 * This case means that a zone whose size was 0 gets new memory
5193 * via memory hot-add.
5194 * But it may be the case that a new node was hot-added. In
5195 * this case vmalloc() will not be able to use this new node's
5196 * memory - this wait_table must be initialized to use this new
5197 * node itself as well.
5198 * To use this new node's memory, further consideration will be
5199 * necessary.
5200 */
5201 zone->wait_table = vmalloc(alloc_size);
5202 }
5203 if (!zone->wait_table)
5204 return -ENOMEM;
5205
5206 for (i = 0; i < zone->wait_table_hash_nr_entries; ++i)
5207 init_waitqueue_head(zone->wait_table + i);
5208
5209 return 0;
5210 }
5211
5212 static __meminit void zone_pcp_init(struct zone *zone)
5213 {
5214 /*
5215 * per cpu subsystem is not up at this point. The following code
5216 * relies on the ability of the linker to provide the
5217 * offset of a (static) per cpu variable into the per cpu area.
5218 */
5219 zone->pageset = &boot_pageset;
5220
5221 if (populated_zone(zone))
5222 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
5223 zone->name, zone->present_pages,
5224 zone_batchsize(zone));
5225 }
5226
5227 int __meminit init_currently_empty_zone(struct zone *zone,
5228 unsigned long zone_start_pfn,
5229 unsigned long size)
5230 {
5231 struct pglist_data *pgdat = zone->zone_pgdat;
5232 int ret;
5233 ret = zone_wait_table_init(zone, size);
5234 if (ret)
5235 return ret;
5236 pgdat->nr_zones = zone_idx(zone) + 1;
5237
5238 zone->zone_start_pfn = zone_start_pfn;
5239
5240 mminit_dprintk(MMINIT_TRACE, "memmap_init",
5241 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
5242 pgdat->node_id,
5243 (unsigned long)zone_idx(zone),
5244 zone_start_pfn, (zone_start_pfn + size));
5245
5246 zone_init_free_lists(zone);
5247
5248 return 0;
5249 }
5250
5251 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5252 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5253
5254 /*
5255 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5256 */
5257 int __meminit __early_pfn_to_nid(unsigned long pfn,
5258 struct mminit_pfnnid_cache *state)
5259 {
5260 unsigned long start_pfn, end_pfn;
5261 int nid;
5262
5263 if (state->last_start <= pfn && pfn < state->last_end)
5264 return state->last_nid;
5265
5266 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
5267 if (nid != -1) {
5268 state->last_start = start_pfn;
5269 state->last_end = end_pfn;
5270 state->last_nid = nid;
5271 }
5272
5273 return nid;
5274 }
5275 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5276
5277 /**
5278 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5279 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5280 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5281 *
5282 * If an architecture guarantees that all ranges registered contain no holes
5283 * and may be freed, this this function may be used instead of calling
5284 * memblock_free_early_nid() manually.
5285 */
5286 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
5287 {
5288 unsigned long start_pfn, end_pfn;
5289 int i, this_nid;
5290
5291 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
5292 start_pfn = min(start_pfn, max_low_pfn);
5293 end_pfn = min(end_pfn, max_low_pfn);
5294
5295 if (start_pfn < end_pfn)
5296 memblock_free_early_nid(PFN_PHYS(start_pfn),
5297 (end_pfn - start_pfn) << PAGE_SHIFT,
5298 this_nid);
5299 }
5300 }
5301
5302 /**
5303 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5304 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5305 *
5306 * If an architecture guarantees that all ranges registered contain no holes and may
5307 * be freed, this function may be used instead of calling memory_present() manually.
5308 */
5309 void __init sparse_memory_present_with_active_regions(int nid)
5310 {
5311 unsigned long start_pfn, end_pfn;
5312 int i, this_nid;
5313
5314 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
5315 memory_present(this_nid, start_pfn, end_pfn);
5316 }
5317
5318 /**
5319 * get_pfn_range_for_nid - Return the start and end page frames for a node
5320 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5321 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5322 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5323 *
5324 * It returns the start and end page frame of a node based on information
5325 * provided by memblock_set_node(). If called for a node
5326 * with no available memory, a warning is printed and the start and end
5327 * PFNs will be 0.
5328 */
5329 void __meminit get_pfn_range_for_nid(unsigned int nid,
5330 unsigned long *start_pfn, unsigned long *end_pfn)
5331 {
5332 unsigned long this_start_pfn, this_end_pfn;
5333 int i;
5334
5335 *start_pfn = -1UL;
5336 *end_pfn = 0;
5337
5338 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
5339 *start_pfn = min(*start_pfn, this_start_pfn);
5340 *end_pfn = max(*end_pfn, this_end_pfn);
5341 }
5342
5343 if (*start_pfn == -1UL)
5344 *start_pfn = 0;
5345 }
5346
5347 /*
5348 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5349 * assumption is made that zones within a node are ordered in monotonic
5350 * increasing memory addresses so that the "highest" populated zone is used
5351 */
5352 static void __init find_usable_zone_for_movable(void)
5353 {
5354 int zone_index;
5355 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
5356 if (zone_index == ZONE_MOVABLE)
5357 continue;
5358
5359 if (arch_zone_highest_possible_pfn[zone_index] >
5360 arch_zone_lowest_possible_pfn[zone_index])
5361 break;
5362 }
5363
5364 VM_BUG_ON(zone_index == -1);
5365 movable_zone = zone_index;
5366 }
5367
5368 /*
5369 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5370 * because it is sized independent of architecture. Unlike the other zones,
5371 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5372 * in each node depending on the size of each node and how evenly kernelcore
5373 * is distributed. This helper function adjusts the zone ranges
5374 * provided by the architecture for a given node by using the end of the
5375 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5376 * zones within a node are in order of monotonic increases memory addresses
5377 */
5378 static void __meminit adjust_zone_range_for_zone_movable(int nid,
5379 unsigned long zone_type,
5380 unsigned long node_start_pfn,
5381 unsigned long node_end_pfn,
5382 unsigned long *zone_start_pfn,
5383 unsigned long *zone_end_pfn)
5384 {
5385 /* Only adjust if ZONE_MOVABLE is on this node */
5386 if (zone_movable_pfn[nid]) {
5387 /* Size ZONE_MOVABLE */
5388 if (zone_type == ZONE_MOVABLE) {
5389 *zone_start_pfn = zone_movable_pfn[nid];
5390 *zone_end_pfn = min(node_end_pfn,
5391 arch_zone_highest_possible_pfn[movable_zone]);
5392
5393 /* Check if this whole range is within ZONE_MOVABLE */
5394 } else if (*zone_start_pfn >= zone_movable_pfn[nid])
5395 *zone_start_pfn = *zone_end_pfn;
5396 }
5397 }
5398
5399 /*
5400 * Return the number of pages a zone spans in a node, including holes
5401 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5402 */
5403 static unsigned long __meminit zone_spanned_pages_in_node(int nid,
5404 unsigned long zone_type,
5405 unsigned long node_start_pfn,
5406 unsigned long node_end_pfn,
5407 unsigned long *zone_start_pfn,
5408 unsigned long *zone_end_pfn,
5409 unsigned long *ignored)
5410 {
5411 /* When hotadd a new node from cpu_up(), the node should be empty */
5412 if (!node_start_pfn && !node_end_pfn)
5413 return 0;
5414
5415 /* Get the start and end of the zone */
5416 *zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
5417 *zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
5418 adjust_zone_range_for_zone_movable(nid, zone_type,
5419 node_start_pfn, node_end_pfn,
5420 zone_start_pfn, zone_end_pfn);
5421
5422 /* Check that this node has pages within the zone's required range */
5423 if (*zone_end_pfn < node_start_pfn || *zone_start_pfn > node_end_pfn)
5424 return 0;
5425
5426 /* Move the zone boundaries inside the node if necessary */
5427 *zone_end_pfn = min(*zone_end_pfn, node_end_pfn);
5428 *zone_start_pfn = max(*zone_start_pfn, node_start_pfn);
5429
5430 /* Return the spanned pages */
5431 return *zone_end_pfn - *zone_start_pfn;
5432 }
5433
5434 /*
5435 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5436 * then all holes in the requested range will be accounted for.
5437 */
5438 unsigned long __meminit __absent_pages_in_range(int nid,
5439 unsigned long range_start_pfn,
5440 unsigned long range_end_pfn)
5441 {
5442 unsigned long nr_absent = range_end_pfn - range_start_pfn;
5443 unsigned long start_pfn, end_pfn;
5444 int i;
5445
5446 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
5447 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
5448 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
5449 nr_absent -= end_pfn - start_pfn;
5450 }
5451 return nr_absent;
5452 }
5453
5454 /**
5455 * absent_pages_in_range - Return number of page frames in holes within a range
5456 * @start_pfn: The start PFN to start searching for holes
5457 * @end_pfn: The end PFN to stop searching for holes
5458 *
5459 * It returns the number of pages frames in memory holes within a range.
5460 */
5461 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
5462 unsigned long end_pfn)
5463 {
5464 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
5465 }
5466
5467 /* Return the number of page frames in holes in a zone on a node */
5468 static unsigned long __meminit zone_absent_pages_in_node(int nid,
5469 unsigned long zone_type,
5470 unsigned long node_start_pfn,
5471 unsigned long node_end_pfn,
5472 unsigned long *ignored)
5473 {
5474 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
5475 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
5476 unsigned long zone_start_pfn, zone_end_pfn;
5477 unsigned long nr_absent;
5478
5479 /* When hotadd a new node from cpu_up(), the node should be empty */
5480 if (!node_start_pfn && !node_end_pfn)
5481 return 0;
5482
5483 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
5484 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
5485
5486 adjust_zone_range_for_zone_movable(nid, zone_type,
5487 node_start_pfn, node_end_pfn,
5488 &zone_start_pfn, &zone_end_pfn);
5489 nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
5490
5491 /*
5492 * ZONE_MOVABLE handling.
5493 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5494 * and vice versa.
5495 */
5496 if (zone_movable_pfn[nid]) {
5497 if (mirrored_kernelcore) {
5498 unsigned long start_pfn, end_pfn;
5499 struct memblock_region *r;
5500
5501 for_each_memblock(memory, r) {
5502 start_pfn = clamp(memblock_region_memory_base_pfn(r),
5503 zone_start_pfn, zone_end_pfn);
5504 end_pfn = clamp(memblock_region_memory_end_pfn(r),
5505 zone_start_pfn, zone_end_pfn);
5506
5507 if (zone_type == ZONE_MOVABLE &&
5508 memblock_is_mirror(r))
5509 nr_absent += end_pfn - start_pfn;
5510
5511 if (zone_type == ZONE_NORMAL &&
5512 !memblock_is_mirror(r))
5513 nr_absent += end_pfn - start_pfn;
5514 }
5515 } else {
5516 if (zone_type == ZONE_NORMAL)
5517 nr_absent += node_end_pfn - zone_movable_pfn[nid];
5518 }
5519 }
5520
5521 return nr_absent;
5522 }
5523
5524 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5525 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
5526 unsigned long zone_type,
5527 unsigned long node_start_pfn,
5528 unsigned long node_end_pfn,
5529 unsigned long *zone_start_pfn,
5530 unsigned long *zone_end_pfn,
5531 unsigned long *zones_size)
5532 {
5533 unsigned int zone;
5534
5535 *zone_start_pfn = node_start_pfn;
5536 for (zone = 0; zone < zone_type; zone++)
5537 *zone_start_pfn += zones_size[zone];
5538
5539 *zone_end_pfn = *zone_start_pfn + zones_size[zone_type];
5540
5541 return zones_size[zone_type];
5542 }
5543
5544 static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
5545 unsigned long zone_type,
5546 unsigned long node_start_pfn,
5547 unsigned long node_end_pfn,
5548 unsigned long *zholes_size)
5549 {
5550 if (!zholes_size)
5551 return 0;
5552
5553 return zholes_size[zone_type];
5554 }
5555
5556 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5557
5558 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
5559 unsigned long node_start_pfn,
5560 unsigned long node_end_pfn,
5561 unsigned long *zones_size,
5562 unsigned long *zholes_size)
5563 {
5564 unsigned long realtotalpages = 0, totalpages = 0;
5565 enum zone_type i;
5566
5567 for (i = 0; i < MAX_NR_ZONES; i++) {
5568 struct zone *zone = pgdat->node_zones + i;
5569 unsigned long zone_start_pfn, zone_end_pfn;
5570 unsigned long size, real_size;
5571
5572 size = zone_spanned_pages_in_node(pgdat->node_id, i,
5573 node_start_pfn,
5574 node_end_pfn,
5575 &zone_start_pfn,
5576 &zone_end_pfn,
5577 zones_size);
5578 real_size = size - zone_absent_pages_in_node(pgdat->node_id, i,
5579 node_start_pfn, node_end_pfn,
5580 zholes_size);
5581 if (size)
5582 zone->zone_start_pfn = zone_start_pfn;
5583 else
5584 zone->zone_start_pfn = 0;
5585 zone->spanned_pages = size;
5586 zone->present_pages = real_size;
5587
5588 totalpages += size;
5589 realtotalpages += real_size;
5590 }
5591
5592 pgdat->node_spanned_pages = totalpages;
5593 pgdat->node_present_pages = realtotalpages;
5594 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
5595 realtotalpages);
5596 }
5597
5598 #ifndef CONFIG_SPARSEMEM
5599 /*
5600 * Calculate the size of the zone->blockflags rounded to an unsigned long
5601 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5602 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5603 * round what is now in bits to nearest long in bits, then return it in
5604 * bytes.
5605 */
5606 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize)
5607 {
5608 unsigned long usemapsize;
5609
5610 zonesize += zone_start_pfn & (pageblock_nr_pages-1);
5611 usemapsize = roundup(zonesize, pageblock_nr_pages);
5612 usemapsize = usemapsize >> pageblock_order;
5613 usemapsize *= NR_PAGEBLOCK_BITS;
5614 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
5615
5616 return usemapsize / 8;
5617 }
5618
5619 static void __init setup_usemap(struct pglist_data *pgdat,
5620 struct zone *zone,
5621 unsigned long zone_start_pfn,
5622 unsigned long zonesize)
5623 {
5624 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
5625 zone->pageblock_flags = NULL;
5626 if (usemapsize)
5627 zone->pageblock_flags =
5628 memblock_virt_alloc_node_nopanic(usemapsize,
5629 pgdat->node_id);
5630 }
5631 #else
5632 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
5633 unsigned long zone_start_pfn, unsigned long zonesize) {}
5634 #endif /* CONFIG_SPARSEMEM */
5635
5636 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5637
5638 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5639 void __paginginit set_pageblock_order(void)
5640 {
5641 unsigned int order;
5642
5643 /* Check that pageblock_nr_pages has not already been setup */
5644 if (pageblock_order)
5645 return;
5646
5647 if (HPAGE_SHIFT > PAGE_SHIFT)
5648 order = HUGETLB_PAGE_ORDER;
5649 else
5650 order = MAX_ORDER - 1;
5651
5652 /*
5653 * Assume the largest contiguous order of interest is a huge page.
5654 * This value may be variable depending on boot parameters on IA64 and
5655 * powerpc.
5656 */
5657 pageblock_order = order;
5658 }
5659 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5660
5661 /*
5662 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5663 * is unused as pageblock_order is set at compile-time. See
5664 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5665 * the kernel config
5666 */
5667 void __paginginit set_pageblock_order(void)
5668 {
5669 }
5670
5671 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5672
5673 static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
5674 unsigned long present_pages)
5675 {
5676 unsigned long pages = spanned_pages;
5677
5678 /*
5679 * Provide a more accurate estimation if there are holes within
5680 * the zone and SPARSEMEM is in use. If there are holes within the
5681 * zone, each populated memory region may cost us one or two extra
5682 * memmap pages due to alignment because memmap pages for each
5683 * populated regions may not naturally algined on page boundary.
5684 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5685 */
5686 if (spanned_pages > present_pages + (present_pages >> 4) &&
5687 IS_ENABLED(CONFIG_SPARSEMEM))
5688 pages = present_pages;
5689
5690 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
5691 }
5692
5693 /*
5694 * Set up the zone data structures:
5695 * - mark all pages reserved
5696 * - mark all memory queues empty
5697 * - clear the memory bitmaps
5698 *
5699 * NOTE: pgdat should get zeroed by caller.
5700 */
5701 static void __paginginit free_area_init_core(struct pglist_data *pgdat)
5702 {
5703 enum zone_type j;
5704 int nid = pgdat->node_id;
5705 int ret;
5706
5707 pgdat_resize_init(pgdat);
5708 #ifdef CONFIG_NUMA_BALANCING
5709 spin_lock_init(&pgdat->numabalancing_migrate_lock);
5710 pgdat->numabalancing_migrate_nr_pages = 0;
5711 pgdat->numabalancing_migrate_next_window = jiffies;
5712 #endif
5713 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5714 spin_lock_init(&pgdat->split_queue_lock);
5715 INIT_LIST_HEAD(&pgdat->split_queue);
5716 pgdat->split_queue_len = 0;
5717 #endif
5718 init_waitqueue_head(&pgdat->kswapd_wait);
5719 init_waitqueue_head(&pgdat->pfmemalloc_wait);
5720 #ifdef CONFIG_COMPACTION
5721 init_waitqueue_head(&pgdat->kcompactd_wait);
5722 #endif
5723 pgdat_page_ext_init(pgdat);
5724
5725 for (j = 0; j < MAX_NR_ZONES; j++) {
5726 struct zone *zone = pgdat->node_zones + j;
5727 unsigned long size, realsize, freesize, memmap_pages;
5728 unsigned long zone_start_pfn = zone->zone_start_pfn;
5729
5730 size = zone->spanned_pages;
5731 realsize = freesize = zone->present_pages;
5732
5733 /*
5734 * Adjust freesize so that it accounts for how much memory
5735 * is used by this zone for memmap. This affects the watermark
5736 * and per-cpu initialisations
5737 */
5738 memmap_pages = calc_memmap_size(size, realsize);
5739 if (!is_highmem_idx(j)) {
5740 if (freesize >= memmap_pages) {
5741 freesize -= memmap_pages;
5742 if (memmap_pages)
5743 printk(KERN_DEBUG
5744 " %s zone: %lu pages used for memmap\n",
5745 zone_names[j], memmap_pages);
5746 } else
5747 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
5748 zone_names[j], memmap_pages, freesize);
5749 }
5750
5751 /* Account for reserved pages */
5752 if (j == 0 && freesize > dma_reserve) {
5753 freesize -= dma_reserve;
5754 printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
5755 zone_names[0], dma_reserve);
5756 }
5757
5758 if (!is_highmem_idx(j))
5759 nr_kernel_pages += freesize;
5760 /* Charge for highmem memmap if there are enough kernel pages */
5761 else if (nr_kernel_pages > memmap_pages * 2)
5762 nr_kernel_pages -= memmap_pages;
5763 nr_all_pages += freesize;
5764
5765 /*
5766 * Set an approximate value for lowmem here, it will be adjusted
5767 * when the bootmem allocator frees pages into the buddy system.
5768 * And all highmem pages will be managed by the buddy system.
5769 */
5770 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
5771 #ifdef CONFIG_NUMA
5772 zone->node = nid;
5773 zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio)
5774 / 100;
5775 zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100;
5776 #endif
5777 zone->name = zone_names[j];
5778 spin_lock_init(&zone->lock);
5779 spin_lock_init(&zone->lru_lock);
5780 zone_seqlock_init(zone);
5781 zone->zone_pgdat = pgdat;
5782 zone_pcp_init(zone);
5783
5784 /* For bootup, initialized properly in watermark setup */
5785 mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages);
5786
5787 lruvec_init(&zone->lruvec);
5788 if (!size)
5789 continue;
5790
5791 set_pageblock_order();
5792 setup_usemap(pgdat, zone, zone_start_pfn, size);
5793 ret = init_currently_empty_zone(zone, zone_start_pfn, size);
5794 BUG_ON(ret);
5795 memmap_init(size, nid, j, zone_start_pfn);
5796 }
5797 }
5798
5799 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
5800 {
5801 unsigned long __maybe_unused start = 0;
5802 unsigned long __maybe_unused offset = 0;
5803
5804 /* Skip empty nodes */
5805 if (!pgdat->node_spanned_pages)
5806 return;
5807
5808 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5809 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
5810 offset = pgdat->node_start_pfn - start;
5811 /* ia64 gets its own node_mem_map, before this, without bootmem */
5812 if (!pgdat->node_mem_map) {
5813 unsigned long size, end;
5814 struct page *map;
5815
5816 /*
5817 * The zone's endpoints aren't required to be MAX_ORDER
5818 * aligned but the node_mem_map endpoints must be in order
5819 * for the buddy allocator to function correctly.
5820 */
5821 end = pgdat_end_pfn(pgdat);
5822 end = ALIGN(end, MAX_ORDER_NR_PAGES);
5823 size = (end - start) * sizeof(struct page);
5824 map = alloc_remap(pgdat->node_id, size);
5825 if (!map)
5826 map = memblock_virt_alloc_node_nopanic(size,
5827 pgdat->node_id);
5828 pgdat->node_mem_map = map + offset;
5829 }
5830 #ifndef CONFIG_NEED_MULTIPLE_NODES
5831 /*
5832 * With no DISCONTIG, the global mem_map is just set as node 0's
5833 */
5834 if (pgdat == NODE_DATA(0)) {
5835 mem_map = NODE_DATA(0)->node_mem_map;
5836 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
5837 if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
5838 mem_map -= offset;
5839 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5840 }
5841 #endif
5842 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
5843 }
5844
5845 void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
5846 unsigned long node_start_pfn, unsigned long *zholes_size)
5847 {
5848 pg_data_t *pgdat = NODE_DATA(nid);
5849 unsigned long start_pfn = 0;
5850 unsigned long end_pfn = 0;
5851
5852 /* pg_data_t should be reset to zero when it's allocated */
5853 WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
5854
5855 reset_deferred_meminit(pgdat);
5856 pgdat->node_id = nid;
5857 pgdat->node_start_pfn = node_start_pfn;
5858 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5859 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
5860 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
5861 (u64)start_pfn << PAGE_SHIFT,
5862 end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
5863 #else
5864 start_pfn = node_start_pfn;
5865 #endif
5866 calculate_node_totalpages(pgdat, start_pfn, end_pfn,
5867 zones_size, zholes_size);
5868
5869 alloc_node_mem_map(pgdat);
5870 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5871 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
5872 nid, (unsigned long)pgdat,
5873 (unsigned long)pgdat->node_mem_map);
5874 #endif
5875
5876 free_area_init_core(pgdat);
5877 }
5878
5879 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5880
5881 #if MAX_NUMNODES > 1
5882 /*
5883 * Figure out the number of possible node ids.
5884 */
5885 void __init setup_nr_node_ids(void)
5886 {
5887 unsigned int highest;
5888
5889 highest = find_last_bit(node_possible_map.bits, MAX_NUMNODES);
5890 nr_node_ids = highest + 1;
5891 }
5892 #endif
5893
5894 /**
5895 * node_map_pfn_alignment - determine the maximum internode alignment
5896 *
5897 * This function should be called after node map is populated and sorted.
5898 * It calculates the maximum power of two alignment which can distinguish
5899 * all the nodes.
5900 *
5901 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5902 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5903 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5904 * shifted, 1GiB is enough and this function will indicate so.
5905 *
5906 * This is used to test whether pfn -> nid mapping of the chosen memory
5907 * model has fine enough granularity to avoid incorrect mapping for the
5908 * populated node map.
5909 *
5910 * Returns the determined alignment in pfn's. 0 if there is no alignment
5911 * requirement (single node).
5912 */
5913 unsigned long __init node_map_pfn_alignment(void)
5914 {
5915 unsigned long accl_mask = 0, last_end = 0;
5916 unsigned long start, end, mask;
5917 int last_nid = -1;
5918 int i, nid;
5919
5920 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
5921 if (!start || last_nid < 0 || last_nid == nid) {
5922 last_nid = nid;
5923 last_end = end;
5924 continue;
5925 }
5926
5927 /*
5928 * Start with a mask granular enough to pin-point to the
5929 * start pfn and tick off bits one-by-one until it becomes
5930 * too coarse to separate the current node from the last.
5931 */
5932 mask = ~((1 << __ffs(start)) - 1);
5933 while (mask && last_end <= (start & (mask << 1)))
5934 mask <<= 1;
5935
5936 /* accumulate all internode masks */
5937 accl_mask |= mask;
5938 }
5939
5940 /* convert mask to number of pages */
5941 return ~accl_mask + 1;
5942 }
5943
5944 /* Find the lowest pfn for a node */
5945 static unsigned long __init find_min_pfn_for_node(int nid)
5946 {
5947 unsigned long min_pfn = ULONG_MAX;
5948 unsigned long start_pfn;
5949 int i;
5950
5951 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
5952 min_pfn = min(min_pfn, start_pfn);
5953
5954 if (min_pfn == ULONG_MAX) {
5955 pr_warn("Could not find start_pfn for node %d\n", nid);
5956 return 0;
5957 }
5958
5959 return min_pfn;
5960 }
5961
5962 /**
5963 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5964 *
5965 * It returns the minimum PFN based on information provided via
5966 * memblock_set_node().
5967 */
5968 unsigned long __init find_min_pfn_with_active_regions(void)
5969 {
5970 return find_min_pfn_for_node(MAX_NUMNODES);
5971 }
5972
5973 /*
5974 * early_calculate_totalpages()
5975 * Sum pages in active regions for movable zone.
5976 * Populate N_MEMORY for calculating usable_nodes.
5977 */
5978 static unsigned long __init early_calculate_totalpages(void)
5979 {
5980 unsigned long totalpages = 0;
5981 unsigned long start_pfn, end_pfn;
5982 int i, nid;
5983
5984 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
5985 unsigned long pages = end_pfn - start_pfn;
5986
5987 totalpages += pages;
5988 if (pages)
5989 node_set_state(nid, N_MEMORY);
5990 }
5991 return totalpages;
5992 }
5993
5994 /*
5995 * Find the PFN the Movable zone begins in each node. Kernel memory
5996 * is spread evenly between nodes as long as the nodes have enough
5997 * memory. When they don't, some nodes will have more kernelcore than
5998 * others
5999 */
6000 static void __init find_zone_movable_pfns_for_nodes(void)
6001 {
6002 int i, nid;
6003 unsigned long usable_startpfn;
6004 unsigned long kernelcore_node, kernelcore_remaining;
6005 /* save the state before borrow the nodemask */
6006 nodemask_t saved_node_state = node_states[N_MEMORY];
6007 unsigned long totalpages = early_calculate_totalpages();
6008 int usable_nodes = nodes_weight(node_states[N_MEMORY]);
6009 struct memblock_region *r;
6010
6011 /* Need to find movable_zone earlier when movable_node is specified. */
6012 find_usable_zone_for_movable();
6013
6014 /*
6015 * If movable_node is specified, ignore kernelcore and movablecore
6016 * options.
6017 */
6018 if (movable_node_is_enabled()) {
6019 for_each_memblock(memory, r) {
6020 if (!memblock_is_hotpluggable(r))
6021 continue;
6022
6023 nid = r->nid;
6024
6025 usable_startpfn = PFN_DOWN(r->base);
6026 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
6027 min(usable_startpfn, zone_movable_pfn[nid]) :
6028 usable_startpfn;
6029 }
6030
6031 goto out2;
6032 }
6033
6034 /*
6035 * If kernelcore=mirror is specified, ignore movablecore option
6036 */
6037 if (mirrored_kernelcore) {
6038 bool mem_below_4gb_not_mirrored = false;
6039
6040 for_each_memblock(memory, r) {
6041 if (memblock_is_mirror(r))
6042 continue;
6043
6044 nid = r->nid;
6045
6046 usable_startpfn = memblock_region_memory_base_pfn(r);
6047
6048 if (usable_startpfn < 0x100000) {
6049 mem_below_4gb_not_mirrored = true;
6050 continue;
6051 }
6052
6053 zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
6054 min(usable_startpfn, zone_movable_pfn[nid]) :
6055 usable_startpfn;
6056 }
6057
6058 if (mem_below_4gb_not_mirrored)
6059 pr_warn("This configuration results in unmirrored kernel memory.");
6060
6061 goto out2;
6062 }
6063
6064 /*
6065 * If movablecore=nn[KMG] was specified, calculate what size of
6066 * kernelcore that corresponds so that memory usable for
6067 * any allocation type is evenly spread. If both kernelcore
6068 * and movablecore are specified, then the value of kernelcore
6069 * will be used for required_kernelcore if it's greater than
6070 * what movablecore would have allowed.
6071 */
6072 if (required_movablecore) {
6073 unsigned long corepages;
6074
6075 /*
6076 * Round-up so that ZONE_MOVABLE is at least as large as what
6077 * was requested by the user
6078 */
6079 required_movablecore =
6080 roundup(required_movablecore, MAX_ORDER_NR_PAGES);
6081 required_movablecore = min(totalpages, required_movablecore);
6082 corepages = totalpages - required_movablecore;
6083
6084 required_kernelcore = max(required_kernelcore, corepages);
6085 }
6086
6087 /*
6088 * If kernelcore was not specified or kernelcore size is larger
6089 * than totalpages, there is no ZONE_MOVABLE.
6090 */
6091 if (!required_kernelcore || required_kernelcore >= totalpages)
6092 goto out;
6093
6094 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
6095 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
6096
6097 restart:
6098 /* Spread kernelcore memory as evenly as possible throughout nodes */
6099 kernelcore_node = required_kernelcore / usable_nodes;
6100 for_each_node_state(nid, N_MEMORY) {
6101 unsigned long start_pfn, end_pfn;
6102
6103 /*
6104 * Recalculate kernelcore_node if the division per node
6105 * now exceeds what is necessary to satisfy the requested
6106 * amount of memory for the kernel
6107 */
6108 if (required_kernelcore < kernelcore_node)
6109 kernelcore_node = required_kernelcore / usable_nodes;
6110
6111 /*
6112 * As the map is walked, we track how much memory is usable
6113 * by the kernel using kernelcore_remaining. When it is
6114 * 0, the rest of the node is usable by ZONE_MOVABLE
6115 */
6116 kernelcore_remaining = kernelcore_node;
6117
6118 /* Go through each range of PFNs within this node */
6119 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
6120 unsigned long size_pages;
6121
6122 start_pfn = max(start_pfn, zone_movable_pfn[nid]);
6123 if (start_pfn >= end_pfn)
6124 continue;
6125
6126 /* Account for what is only usable for kernelcore */
6127 if (start_pfn < usable_startpfn) {
6128 unsigned long kernel_pages;
6129 kernel_pages = min(end_pfn, usable_startpfn)
6130 - start_pfn;
6131
6132 kernelcore_remaining -= min(kernel_pages,
6133 kernelcore_remaining);
6134 required_kernelcore -= min(kernel_pages,
6135 required_kernelcore);
6136
6137 /* Continue if range is now fully accounted */
6138 if (end_pfn <= usable_startpfn) {
6139
6140 /*
6141 * Push zone_movable_pfn to the end so
6142 * that if we have to rebalance
6143 * kernelcore across nodes, we will
6144 * not double account here
6145 */
6146 zone_movable_pfn[nid] = end_pfn;
6147 continue;
6148 }
6149 start_pfn = usable_startpfn;
6150 }
6151
6152 /*
6153 * The usable PFN range for ZONE_MOVABLE is from
6154 * start_pfn->end_pfn. Calculate size_pages as the
6155 * number of pages used as kernelcore
6156 */
6157 size_pages = end_pfn - start_pfn;
6158 if (size_pages > kernelcore_remaining)
6159 size_pages = kernelcore_remaining;
6160 zone_movable_pfn[nid] = start_pfn + size_pages;
6161
6162 /*
6163 * Some kernelcore has been met, update counts and
6164 * break if the kernelcore for this node has been
6165 * satisfied
6166 */
6167 required_kernelcore -= min(required_kernelcore,
6168 size_pages);
6169 kernelcore_remaining -= size_pages;
6170 if (!kernelcore_remaining)
6171 break;
6172 }
6173 }
6174
6175 /*
6176 * If there is still required_kernelcore, we do another pass with one
6177 * less node in the count. This will push zone_movable_pfn[nid] further
6178 * along on the nodes that still have memory until kernelcore is
6179 * satisfied
6180 */
6181 usable_nodes--;
6182 if (usable_nodes && required_kernelcore > usable_nodes)
6183 goto restart;
6184
6185 out2:
6186 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
6187 for (nid = 0; nid < MAX_NUMNODES; nid++)
6188 zone_movable_pfn[nid] =
6189 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
6190
6191 out:
6192 /* restore the node_state */
6193 node_states[N_MEMORY] = saved_node_state;
6194 }
6195
6196 /* Any regular or high memory on that node ? */
6197 static void check_for_memory(pg_data_t *pgdat, int nid)
6198 {
6199 enum zone_type zone_type;
6200
6201 if (N_MEMORY == N_NORMAL_MEMORY)
6202 return;
6203
6204 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
6205 struct zone *zone = &pgdat->node_zones[zone_type];
6206 if (populated_zone(zone)) {
6207 node_set_state(nid, N_HIGH_MEMORY);
6208 if (N_NORMAL_MEMORY != N_HIGH_MEMORY &&
6209 zone_type <= ZONE_NORMAL)
6210 node_set_state(nid, N_NORMAL_MEMORY);
6211 break;
6212 }
6213 }
6214 }
6215
6216 /**
6217 * free_area_init_nodes - Initialise all pg_data_t and zone data
6218 * @max_zone_pfn: an array of max PFNs for each zone
6219 *
6220 * This will call free_area_init_node() for each active node in the system.
6221 * Using the page ranges provided by memblock_set_node(), the size of each
6222 * zone in each node and their holes is calculated. If the maximum PFN
6223 * between two adjacent zones match, it is assumed that the zone is empty.
6224 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
6225 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
6226 * starts where the previous one ended. For example, ZONE_DMA32 starts
6227 * at arch_max_dma_pfn.
6228 */
6229 void __init free_area_init_nodes(unsigned long *max_zone_pfn)
6230 {
6231 unsigned long start_pfn, end_pfn;
6232 int i, nid;
6233
6234 /* Record where the zone boundaries are */
6235 memset(arch_zone_lowest_possible_pfn, 0,
6236 sizeof(arch_zone_lowest_possible_pfn));
6237 memset(arch_zone_highest_possible_pfn, 0,
6238 sizeof(arch_zone_highest_possible_pfn));
6239 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
6240 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
6241 for (i = 1; i < MAX_NR_ZONES; i++) {
6242 if (i == ZONE_MOVABLE)
6243 continue;
6244 arch_zone_lowest_possible_pfn[i] =
6245 arch_zone_highest_possible_pfn[i-1];
6246 arch_zone_highest_possible_pfn[i] =
6247 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
6248 }
6249 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
6250 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
6251
6252 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6253 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
6254 find_zone_movable_pfns_for_nodes();
6255
6256 /* Print out the zone ranges */
6257 pr_info("Zone ranges:\n");
6258 for (i = 0; i < MAX_NR_ZONES; i++) {
6259 if (i == ZONE_MOVABLE)
6260 continue;
6261 pr_info(" %-8s ", zone_names[i]);
6262 if (arch_zone_lowest_possible_pfn[i] ==
6263 arch_zone_highest_possible_pfn[i])
6264 pr_cont("empty\n");
6265 else
6266 pr_cont("[mem %#018Lx-%#018Lx]\n",
6267 (u64)arch_zone_lowest_possible_pfn[i]
6268 << PAGE_SHIFT,
6269 ((u64)arch_zone_highest_possible_pfn[i]
6270 << PAGE_SHIFT) - 1);
6271 }
6272
6273 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6274 pr_info("Movable zone start for each node\n");
6275 for (i = 0; i < MAX_NUMNODES; i++) {
6276 if (zone_movable_pfn[i])
6277 pr_info(" Node %d: %#018Lx\n", i,
6278 (u64)zone_movable_pfn[i] << PAGE_SHIFT);
6279 }
6280
6281 /* Print out the early node map */
6282 pr_info("Early memory node ranges\n");
6283 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
6284 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid,
6285 (u64)start_pfn << PAGE_SHIFT,
6286 ((u64)end_pfn << PAGE_SHIFT) - 1);
6287
6288 /* Initialise every node */
6289 mminit_verify_pageflags_layout();
6290 setup_nr_node_ids();
6291 for_each_online_node(nid) {
6292 pg_data_t *pgdat = NODE_DATA(nid);
6293 free_area_init_node(nid, NULL,
6294 find_min_pfn_for_node(nid), NULL);
6295
6296 /* Any memory on that node */
6297 if (pgdat->node_present_pages)
6298 node_set_state(nid, N_MEMORY);
6299 check_for_memory(pgdat, nid);
6300 }
6301 }
6302
6303 static int __init cmdline_parse_core(char *p, unsigned long *core)
6304 {
6305 unsigned long long coremem;
6306 if (!p)
6307 return -EINVAL;
6308
6309 coremem = memparse(p, &p);
6310 *core = coremem >> PAGE_SHIFT;
6311
6312 /* Paranoid check that UL is enough for the coremem value */
6313 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
6314
6315 return 0;
6316 }
6317
6318 /*
6319 * kernelcore=size sets the amount of memory for use for allocations that
6320 * cannot be reclaimed or migrated.
6321 */
6322 static int __init cmdline_parse_kernelcore(char *p)
6323 {
6324 /* parse kernelcore=mirror */
6325 if (parse_option_str(p, "mirror")) {
6326 mirrored_kernelcore = true;
6327 return 0;
6328 }
6329
6330 return cmdline_parse_core(p, &required_kernelcore);
6331 }
6332
6333 /*
6334 * movablecore=size sets the amount of memory for use for allocations that
6335 * can be reclaimed or migrated.
6336 */
6337 static int __init cmdline_parse_movablecore(char *p)
6338 {
6339 return cmdline_parse_core(p, &required_movablecore);
6340 }
6341
6342 early_param("kernelcore", cmdline_parse_kernelcore);
6343 early_param("movablecore", cmdline_parse_movablecore);
6344
6345 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6346
6347 void adjust_managed_page_count(struct page *page, long count)
6348 {
6349 spin_lock(&managed_page_count_lock);
6350 page_zone(page)->managed_pages += count;
6351 totalram_pages += count;
6352 #ifdef CONFIG_HIGHMEM
6353 if (PageHighMem(page))
6354 totalhigh_pages += count;
6355 #endif
6356 spin_unlock(&managed_page_count_lock);
6357 }
6358 EXPORT_SYMBOL(adjust_managed_page_count);
6359
6360 unsigned long free_reserved_area(void *start, void *end, int poison, char *s)
6361 {
6362 void *pos;
6363 unsigned long pages = 0;
6364
6365 start = (void *)PAGE_ALIGN((unsigned long)start);
6366 end = (void *)((unsigned long)end & PAGE_MASK);
6367 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
6368 if ((unsigned int)poison <= 0xFF)
6369 memset(pos, poison, PAGE_SIZE);
6370 free_reserved_page(virt_to_page(pos));
6371 }
6372
6373 if (pages && s)
6374 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
6375 s, pages << (PAGE_SHIFT - 10), start, end);
6376
6377 return pages;
6378 }
6379 EXPORT_SYMBOL(free_reserved_area);
6380
6381 #ifdef CONFIG_HIGHMEM
6382 void free_highmem_page(struct page *page)
6383 {
6384 __free_reserved_page(page);
6385 totalram_pages++;
6386 page_zone(page)->managed_pages++;
6387 totalhigh_pages++;
6388 }
6389 #endif
6390
6391
6392 void __init mem_init_print_info(const char *str)
6393 {
6394 unsigned long physpages, codesize, datasize, rosize, bss_size;
6395 unsigned long init_code_size, init_data_size;
6396
6397 physpages = get_num_physpages();
6398 codesize = _etext - _stext;
6399 datasize = _edata - _sdata;
6400 rosize = __end_rodata - __start_rodata;
6401 bss_size = __bss_stop - __bss_start;
6402 init_data_size = __init_end - __init_begin;
6403 init_code_size = _einittext - _sinittext;
6404
6405 /*
6406 * Detect special cases and adjust section sizes accordingly:
6407 * 1) .init.* may be embedded into .data sections
6408 * 2) .init.text.* may be out of [__init_begin, __init_end],
6409 * please refer to arch/tile/kernel/vmlinux.lds.S.
6410 * 3) .rodata.* may be embedded into .text or .data sections.
6411 */
6412 #define adj_init_size(start, end, size, pos, adj) \
6413 do { \
6414 if (start <= pos && pos < end && size > adj) \
6415 size -= adj; \
6416 } while (0)
6417
6418 adj_init_size(__init_begin, __init_end, init_data_size,
6419 _sinittext, init_code_size);
6420 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
6421 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
6422 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
6423 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
6424
6425 #undef adj_init_size
6426
6427 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6428 #ifdef CONFIG_HIGHMEM
6429 ", %luK highmem"
6430 #endif
6431 "%s%s)\n",
6432 nr_free_pages() << (PAGE_SHIFT - 10),
6433 physpages << (PAGE_SHIFT - 10),
6434 codesize >> 10, datasize >> 10, rosize >> 10,
6435 (init_data_size + init_code_size) >> 10, bss_size >> 10,
6436 (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT - 10),
6437 totalcma_pages << (PAGE_SHIFT - 10),
6438 #ifdef CONFIG_HIGHMEM
6439 totalhigh_pages << (PAGE_SHIFT - 10),
6440 #endif
6441 str ? ", " : "", str ? str : "");
6442 }
6443
6444 /**
6445 * set_dma_reserve - set the specified number of pages reserved in the first zone
6446 * @new_dma_reserve: The number of pages to mark reserved
6447 *
6448 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6449 * In the DMA zone, a significant percentage may be consumed by kernel image
6450 * and other unfreeable allocations which can skew the watermarks badly. This
6451 * function may optionally be used to account for unfreeable pages in the
6452 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6453 * smaller per-cpu batchsize.
6454 */
6455 void __init set_dma_reserve(unsigned long new_dma_reserve)
6456 {
6457 dma_reserve = new_dma_reserve;
6458 }
6459
6460 void __init free_area_init(unsigned long *zones_size)
6461 {
6462 free_area_init_node(0, zones_size,
6463 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
6464 }
6465
6466 static int page_alloc_cpu_notify(struct notifier_block *self,
6467 unsigned long action, void *hcpu)
6468 {
6469 int cpu = (unsigned long)hcpu;
6470
6471 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
6472 lru_add_drain_cpu(cpu);
6473 drain_pages(cpu);
6474
6475 /*
6476 * Spill the event counters of the dead processor
6477 * into the current processors event counters.
6478 * This artificially elevates the count of the current
6479 * processor.
6480 */
6481 vm_events_fold_cpu(cpu);
6482
6483 /*
6484 * Zero the differential counters of the dead processor
6485 * so that the vm statistics are consistent.
6486 *
6487 * This is only okay since the processor is dead and cannot
6488 * race with what we are doing.
6489 */
6490 cpu_vm_stats_fold(cpu);
6491 }
6492 return NOTIFY_OK;
6493 }
6494
6495 void __init page_alloc_init(void)
6496 {
6497 hotcpu_notifier(page_alloc_cpu_notify, 0);
6498 }
6499
6500 /*
6501 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6502 * or min_free_kbytes changes.
6503 */
6504 static void calculate_totalreserve_pages(void)
6505 {
6506 struct pglist_data *pgdat;
6507 unsigned long reserve_pages = 0;
6508 enum zone_type i, j;
6509
6510 for_each_online_pgdat(pgdat) {
6511 for (i = 0; i < MAX_NR_ZONES; i++) {
6512 struct zone *zone = pgdat->node_zones + i;
6513 long max = 0;
6514
6515 /* Find valid and maximum lowmem_reserve in the zone */
6516 for (j = i; j < MAX_NR_ZONES; j++) {
6517 if (zone->lowmem_reserve[j] > max)
6518 max = zone->lowmem_reserve[j];
6519 }
6520
6521 /* we treat the high watermark as reserved pages. */
6522 max += high_wmark_pages(zone);
6523
6524 if (max > zone->managed_pages)
6525 max = zone->managed_pages;
6526
6527 zone->totalreserve_pages = max;
6528
6529 reserve_pages += max;
6530 }
6531 }
6532 totalreserve_pages = reserve_pages;
6533 }
6534
6535 /*
6536 * setup_per_zone_lowmem_reserve - called whenever
6537 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6538 * has a correct pages reserved value, so an adequate number of
6539 * pages are left in the zone after a successful __alloc_pages().
6540 */
6541 static void setup_per_zone_lowmem_reserve(void)
6542 {
6543 struct pglist_data *pgdat;
6544 enum zone_type j, idx;
6545
6546 for_each_online_pgdat(pgdat) {
6547 for (j = 0; j < MAX_NR_ZONES; j++) {
6548 struct zone *zone = pgdat->node_zones + j;
6549 unsigned long managed_pages = zone->managed_pages;
6550
6551 zone->lowmem_reserve[j] = 0;
6552
6553 idx = j;
6554 while (idx) {
6555 struct zone *lower_zone;
6556
6557 idx--;
6558
6559 if (sysctl_lowmem_reserve_ratio[idx] < 1)
6560 sysctl_lowmem_reserve_ratio[idx] = 1;
6561
6562 lower_zone = pgdat->node_zones + idx;
6563 lower_zone->lowmem_reserve[j] = managed_pages /
6564 sysctl_lowmem_reserve_ratio[idx];
6565 managed_pages += lower_zone->managed_pages;
6566 }
6567 }
6568 }
6569
6570 /* update totalreserve_pages */
6571 calculate_totalreserve_pages();
6572 }
6573
6574 static void __setup_per_zone_wmarks(void)
6575 {
6576 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
6577 unsigned long lowmem_pages = 0;
6578 struct zone *zone;
6579 unsigned long flags;
6580
6581 /* Calculate total number of !ZONE_HIGHMEM pages */
6582 for_each_zone(zone) {
6583 if (!is_highmem(zone))
6584 lowmem_pages += zone->managed_pages;
6585 }
6586
6587 for_each_zone(zone) {
6588 u64 tmp;
6589
6590 spin_lock_irqsave(&zone->lock, flags);
6591 tmp = (u64)pages_min * zone->managed_pages;
6592 do_div(tmp, lowmem_pages);
6593 if (is_highmem(zone)) {
6594 /*
6595 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6596 * need highmem pages, so cap pages_min to a small
6597 * value here.
6598 *
6599 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6600 * deltas control asynch page reclaim, and so should
6601 * not be capped for highmem.
6602 */
6603 unsigned long min_pages;
6604
6605 min_pages = zone->managed_pages / 1024;
6606 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL);
6607 zone->watermark[WMARK_MIN] = min_pages;
6608 } else {
6609 /*
6610 * If it's a lowmem zone, reserve a number of pages
6611 * proportionate to the zone's size.
6612 */
6613 zone->watermark[WMARK_MIN] = tmp;
6614 }
6615
6616 /*
6617 * Set the kswapd watermarks distance according to the
6618 * scale factor in proportion to available memory, but
6619 * ensure a minimum size on small systems.
6620 */
6621 tmp = max_t(u64, tmp >> 2,
6622 mult_frac(zone->managed_pages,
6623 watermark_scale_factor, 10000));
6624
6625 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + tmp;
6626 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + tmp * 2;
6627
6628 __mod_zone_page_state(zone, NR_ALLOC_BATCH,
6629 high_wmark_pages(zone) - low_wmark_pages(zone) -
6630 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
6631
6632 spin_unlock_irqrestore(&zone->lock, flags);
6633 }
6634
6635 /* update totalreserve_pages */
6636 calculate_totalreserve_pages();
6637 }
6638
6639 /**
6640 * setup_per_zone_wmarks - called when min_free_kbytes changes
6641 * or when memory is hot-{added|removed}
6642 *
6643 * Ensures that the watermark[min,low,high] values for each zone are set
6644 * correctly with respect to min_free_kbytes.
6645 */
6646 void setup_per_zone_wmarks(void)
6647 {
6648 mutex_lock(&zonelists_mutex);
6649 __setup_per_zone_wmarks();
6650 mutex_unlock(&zonelists_mutex);
6651 }
6652
6653 /*
6654 * The inactive anon list should be small enough that the VM never has to
6655 * do too much work, but large enough that each inactive page has a chance
6656 * to be referenced again before it is swapped out.
6657 *
6658 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
6659 * INACTIVE_ANON pages on this zone's LRU, maintained by the
6660 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
6661 * the anonymous pages are kept on the inactive list.
6662 *
6663 * total target max
6664 * memory ratio inactive anon
6665 * -------------------------------------
6666 * 10MB 1 5MB
6667 * 100MB 1 50MB
6668 * 1GB 3 250MB
6669 * 10GB 10 0.9GB
6670 * 100GB 31 3GB
6671 * 1TB 101 10GB
6672 * 10TB 320 32GB
6673 */
6674 static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
6675 {
6676 unsigned int gb, ratio;
6677
6678 /* Zone size in gigabytes */
6679 gb = zone->managed_pages >> (30 - PAGE_SHIFT);
6680 if (gb)
6681 ratio = int_sqrt(10 * gb);
6682 else
6683 ratio = 1;
6684
6685 zone->inactive_ratio = ratio;
6686 }
6687
6688 static void __meminit setup_per_zone_inactive_ratio(void)
6689 {
6690 struct zone *zone;
6691
6692 for_each_zone(zone)
6693 calculate_zone_inactive_ratio(zone);
6694 }
6695
6696 /*
6697 * Initialise min_free_kbytes.
6698 *
6699 * For small machines we want it small (128k min). For large machines
6700 * we want it large (64MB max). But it is not linear, because network
6701 * bandwidth does not increase linearly with machine size. We use
6702 *
6703 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6704 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6705 *
6706 * which yields
6707 *
6708 * 16MB: 512k
6709 * 32MB: 724k
6710 * 64MB: 1024k
6711 * 128MB: 1448k
6712 * 256MB: 2048k
6713 * 512MB: 2896k
6714 * 1024MB: 4096k
6715 * 2048MB: 5792k
6716 * 4096MB: 8192k
6717 * 8192MB: 11584k
6718 * 16384MB: 16384k
6719 */
6720 int __meminit init_per_zone_wmark_min(void)
6721 {
6722 unsigned long lowmem_kbytes;
6723 int new_min_free_kbytes;
6724
6725 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
6726 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
6727
6728 if (new_min_free_kbytes > user_min_free_kbytes) {
6729 min_free_kbytes = new_min_free_kbytes;
6730 if (min_free_kbytes < 128)
6731 min_free_kbytes = 128;
6732 if (min_free_kbytes > 65536)
6733 min_free_kbytes = 65536;
6734 } else {
6735 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6736 new_min_free_kbytes, user_min_free_kbytes);
6737 }
6738 setup_per_zone_wmarks();
6739 refresh_zone_stat_thresholds();
6740 setup_per_zone_lowmem_reserve();
6741 setup_per_zone_inactive_ratio();
6742 return 0;
6743 }
6744 core_initcall(init_per_zone_wmark_min)
6745
6746 /*
6747 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6748 * that we can call two helper functions whenever min_free_kbytes
6749 * changes.
6750 */
6751 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
6752 void __user *buffer, size_t *length, loff_t *ppos)
6753 {
6754 int rc;
6755
6756 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6757 if (rc)
6758 return rc;
6759
6760 if (write) {
6761 user_min_free_kbytes = min_free_kbytes;
6762 setup_per_zone_wmarks();
6763 }
6764 return 0;
6765 }
6766
6767 int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write,
6768 void __user *buffer, size_t *length, loff_t *ppos)
6769 {
6770 int rc;
6771
6772 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6773 if (rc)
6774 return rc;
6775
6776 if (write)
6777 setup_per_zone_wmarks();
6778
6779 return 0;
6780 }
6781
6782 #ifdef CONFIG_NUMA
6783 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
6784 void __user *buffer, size_t *length, loff_t *ppos)
6785 {
6786 struct zone *zone;
6787 int rc;
6788
6789 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6790 if (rc)
6791 return rc;
6792
6793 for_each_zone(zone)
6794 zone->min_unmapped_pages = (zone->managed_pages *
6795 sysctl_min_unmapped_ratio) / 100;
6796 return 0;
6797 }
6798
6799 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
6800 void __user *buffer, size_t *length, loff_t *ppos)
6801 {
6802 struct zone *zone;
6803 int rc;
6804
6805 rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
6806 if (rc)
6807 return rc;
6808
6809 for_each_zone(zone)
6810 zone->min_slab_pages = (zone->managed_pages *
6811 sysctl_min_slab_ratio) / 100;
6812 return 0;
6813 }
6814 #endif
6815
6816 /*
6817 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6818 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6819 * whenever sysctl_lowmem_reserve_ratio changes.
6820 *
6821 * The reserve ratio obviously has absolutely no relation with the
6822 * minimum watermarks. The lowmem reserve ratio can only make sense
6823 * if in function of the boot time zone sizes.
6824 */
6825 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
6826 void __user *buffer, size_t *length, loff_t *ppos)
6827 {
6828 proc_dointvec_minmax(table, write, buffer, length, ppos);
6829 setup_per_zone_lowmem_reserve();
6830 return 0;
6831 }
6832
6833 /*
6834 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6835 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6836 * pagelist can have before it gets flushed back to buddy allocator.
6837 */
6838 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
6839 void __user *buffer, size_t *length, loff_t *ppos)
6840 {
6841 struct zone *zone;
6842 int old_percpu_pagelist_fraction;
6843 int ret;
6844
6845 mutex_lock(&pcp_batch_high_lock);
6846 old_percpu_pagelist_fraction = percpu_pagelist_fraction;
6847
6848 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
6849 if (!write || ret < 0)
6850 goto out;
6851
6852 /* Sanity checking to avoid pcp imbalance */
6853 if (percpu_pagelist_fraction &&
6854 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
6855 percpu_pagelist_fraction = old_percpu_pagelist_fraction;
6856 ret = -EINVAL;
6857 goto out;
6858 }
6859
6860 /* No change? */
6861 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
6862 goto out;
6863
6864 for_each_populated_zone(zone) {
6865 unsigned int cpu;
6866
6867 for_each_possible_cpu(cpu)
6868 pageset_set_high_and_batch(zone,
6869 per_cpu_ptr(zone->pageset, cpu));
6870 }
6871 out:
6872 mutex_unlock(&pcp_batch_high_lock);
6873 return ret;
6874 }
6875
6876 #ifdef CONFIG_NUMA
6877 int hashdist = HASHDIST_DEFAULT;
6878
6879 static int __init set_hashdist(char *str)
6880 {
6881 if (!str)
6882 return 0;
6883 hashdist = simple_strtoul(str, &str, 0);
6884 return 1;
6885 }
6886 __setup("hashdist=", set_hashdist);
6887 #endif
6888
6889 /*
6890 * allocate a large system hash table from bootmem
6891 * - it is assumed that the hash table must contain an exact power-of-2
6892 * quantity of entries
6893 * - limit is the number of hash buckets, not the total allocation size
6894 */
6895 void *__init alloc_large_system_hash(const char *tablename,
6896 unsigned long bucketsize,
6897 unsigned long numentries,
6898 int scale,
6899 int flags,
6900 unsigned int *_hash_shift,
6901 unsigned int *_hash_mask,
6902 unsigned long low_limit,
6903 unsigned long high_limit)
6904 {
6905 unsigned long long max = high_limit;
6906 unsigned long log2qty, size;
6907 void *table = NULL;
6908
6909 /* allow the kernel cmdline to have a say */
6910 if (!numentries) {
6911 /* round applicable memory size up to nearest megabyte */
6912 numentries = nr_kernel_pages;
6913
6914 /* It isn't necessary when PAGE_SIZE >= 1MB */
6915 if (PAGE_SHIFT < 20)
6916 numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
6917
6918 /* limit to 1 bucket per 2^scale bytes of low memory */
6919 if (scale > PAGE_SHIFT)
6920 numentries >>= (scale - PAGE_SHIFT);
6921 else
6922 numentries <<= (PAGE_SHIFT - scale);
6923
6924 /* Make sure we've got at least a 0-order allocation.. */
6925 if (unlikely(flags & HASH_SMALL)) {
6926 /* Makes no sense without HASH_EARLY */
6927 WARN_ON(!(flags & HASH_EARLY));
6928 if (!(numentries >> *_hash_shift)) {
6929 numentries = 1UL << *_hash_shift;
6930 BUG_ON(!numentries);
6931 }
6932 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
6933 numentries = PAGE_SIZE / bucketsize;
6934 }
6935 numentries = roundup_pow_of_two(numentries);
6936
6937 /* limit allocation size to 1/16 total memory by default */
6938 if (max == 0) {
6939 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
6940 do_div(max, bucketsize);
6941 }
6942 max = min(max, 0x80000000ULL);
6943
6944 if (numentries < low_limit)
6945 numentries = low_limit;
6946 if (numentries > max)
6947 numentries = max;
6948
6949 log2qty = ilog2(numentries);
6950
6951 do {
6952 size = bucketsize << log2qty;
6953 if (flags & HASH_EARLY)
6954 table = memblock_virt_alloc_nopanic(size, 0);
6955 else if (hashdist)
6956 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
6957 else {
6958 /*
6959 * If bucketsize is not a power-of-two, we may free
6960 * some pages at the end of hash table which
6961 * alloc_pages_exact() automatically does
6962 */
6963 if (get_order(size) < MAX_ORDER) {
6964 table = alloc_pages_exact(size, GFP_ATOMIC);
6965 kmemleak_alloc(table, size, 1, GFP_ATOMIC);
6966 }
6967 }
6968 } while (!table && size > PAGE_SIZE && --log2qty);
6969
6970 if (!table)
6971 panic("Failed to allocate %s hash table\n", tablename);
6972
6973 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
6974 tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size);
6975
6976 if (_hash_shift)
6977 *_hash_shift = log2qty;
6978 if (_hash_mask)
6979 *_hash_mask = (1 << log2qty) - 1;
6980
6981 return table;
6982 }
6983
6984 /*
6985 * This function checks whether pageblock includes unmovable pages or not.
6986 * If @count is not zero, it is okay to include less @count unmovable pages
6987 *
6988 * PageLRU check without isolation or lru_lock could race so that
6989 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6990 * expect this function should be exact.
6991 */
6992 bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
6993 bool skip_hwpoisoned_pages)
6994 {
6995 unsigned long pfn, iter, found;
6996 int mt;
6997
6998 /*
6999 * For avoiding noise data, lru_add_drain_all() should be called
7000 * If ZONE_MOVABLE, the zone never contains unmovable pages
7001 */
7002 if (zone_idx(zone) == ZONE_MOVABLE)
7003 return false;
7004 mt = get_pageblock_migratetype(page);
7005 if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
7006 return false;
7007
7008 pfn = page_to_pfn(page);
7009 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
7010 unsigned long check = pfn + iter;
7011
7012 if (!pfn_valid_within(check))
7013 continue;
7014
7015 page = pfn_to_page(check);
7016
7017 /*
7018 * Hugepages are not in LRU lists, but they're movable.
7019 * We need not scan over tail pages bacause we don't
7020 * handle each tail page individually in migration.
7021 */
7022 if (PageHuge(page)) {
7023 iter = round_up(iter + 1, 1<<compound_order(page)) - 1;
7024 continue;
7025 }
7026
7027 /*
7028 * We can't use page_count without pin a page
7029 * because another CPU can free compound page.
7030 * This check already skips compound tails of THP
7031 * because their page->_refcount is zero at all time.
7032 */
7033 if (!page_ref_count(page)) {
7034 if (PageBuddy(page))
7035 iter += (1 << page_order(page)) - 1;
7036 continue;
7037 }
7038
7039 /*
7040 * The HWPoisoned page may be not in buddy system, and
7041 * page_count() is not 0.
7042 */
7043 if (skip_hwpoisoned_pages && PageHWPoison(page))
7044 continue;
7045
7046 if (!PageLRU(page))
7047 found++;
7048 /*
7049 * If there are RECLAIMABLE pages, we need to check
7050 * it. But now, memory offline itself doesn't call
7051 * shrink_node_slabs() and it still to be fixed.
7052 */
7053 /*
7054 * If the page is not RAM, page_count()should be 0.
7055 * we don't need more check. This is an _used_ not-movable page.
7056 *
7057 * The problematic thing here is PG_reserved pages. PG_reserved
7058 * is set to both of a memory hole page and a _used_ kernel
7059 * page at boot.
7060 */
7061 if (found > count)
7062 return true;
7063 }
7064 return false;
7065 }
7066
7067 bool is_pageblock_removable_nolock(struct page *page)
7068 {
7069 struct zone *zone;
7070 unsigned long pfn;
7071
7072 /*
7073 * We have to be careful here because we are iterating over memory
7074 * sections which are not zone aware so we might end up outside of
7075 * the zone but still within the section.
7076 * We have to take care about the node as well. If the node is offline
7077 * its NODE_DATA will be NULL - see page_zone.
7078 */
7079 if (!node_online(page_to_nid(page)))
7080 return false;
7081
7082 zone = page_zone(page);
7083 pfn = page_to_pfn(page);
7084 if (!zone_spans_pfn(zone, pfn))
7085 return false;
7086
7087 return !has_unmovable_pages(zone, page, 0, true);
7088 }
7089
7090 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
7091
7092 static unsigned long pfn_max_align_down(unsigned long pfn)
7093 {
7094 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
7095 pageblock_nr_pages) - 1);
7096 }
7097
7098 static unsigned long pfn_max_align_up(unsigned long pfn)
7099 {
7100 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
7101 pageblock_nr_pages));
7102 }
7103
7104 /* [start, end) must belong to a single zone. */
7105 static int __alloc_contig_migrate_range(struct compact_control *cc,
7106 unsigned long start, unsigned long end)
7107 {
7108 /* This function is based on compact_zone() from compaction.c. */
7109 unsigned long nr_reclaimed;
7110 unsigned long pfn = start;
7111 unsigned int tries = 0;
7112 int ret = 0;
7113
7114 migrate_prep();
7115
7116 while (pfn < end || !list_empty(&cc->migratepages)) {
7117 if (fatal_signal_pending(current)) {
7118 ret = -EINTR;
7119 break;
7120 }
7121
7122 if (list_empty(&cc->migratepages)) {
7123 cc->nr_migratepages = 0;
7124 pfn = isolate_migratepages_range(cc, pfn, end);
7125 if (!pfn) {
7126 ret = -EINTR;
7127 break;
7128 }
7129 tries = 0;
7130 } else if (++tries == 5) {
7131 ret = ret < 0 ? ret : -EBUSY;
7132 break;
7133 }
7134
7135 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
7136 &cc->migratepages);
7137 cc->nr_migratepages -= nr_reclaimed;
7138
7139 ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
7140 NULL, 0, cc->mode, MR_CMA);
7141 }
7142 if (ret < 0) {
7143 putback_movable_pages(&cc->migratepages);
7144 return ret;
7145 }
7146 return 0;
7147 }
7148
7149 /**
7150 * alloc_contig_range() -- tries to allocate given range of pages
7151 * @start: start PFN to allocate
7152 * @end: one-past-the-last PFN to allocate
7153 * @migratetype: migratetype of the underlaying pageblocks (either
7154 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7155 * in range must have the same migratetype and it must
7156 * be either of the two.
7157 *
7158 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7159 * aligned, however it's the caller's responsibility to guarantee that
7160 * we are the only thread that changes migrate type of pageblocks the
7161 * pages fall in.
7162 *
7163 * The PFN range must belong to a single zone.
7164 *
7165 * Returns zero on success or negative error code. On success all
7166 * pages which PFN is in [start, end) are allocated for the caller and
7167 * need to be freed with free_contig_range().
7168 */
7169 int alloc_contig_range(unsigned long start, unsigned long end,
7170 unsigned migratetype)
7171 {
7172 unsigned long outer_start, outer_end;
7173 unsigned int order;
7174 int ret = 0;
7175
7176 struct compact_control cc = {
7177 .nr_migratepages = 0,
7178 .order = -1,
7179 .zone = page_zone(pfn_to_page(start)),
7180 .mode = MIGRATE_SYNC,
7181 .ignore_skip_hint = true,
7182 };
7183 INIT_LIST_HEAD(&cc.migratepages);
7184
7185 /*
7186 * What we do here is we mark all pageblocks in range as
7187 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7188 * have different sizes, and due to the way page allocator
7189 * work, we align the range to biggest of the two pages so
7190 * that page allocator won't try to merge buddies from
7191 * different pageblocks and change MIGRATE_ISOLATE to some
7192 * other migration type.
7193 *
7194 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7195 * migrate the pages from an unaligned range (ie. pages that
7196 * we are interested in). This will put all the pages in
7197 * range back to page allocator as MIGRATE_ISOLATE.
7198 *
7199 * When this is done, we take the pages in range from page
7200 * allocator removing them from the buddy system. This way
7201 * page allocator will never consider using them.
7202 *
7203 * This lets us mark the pageblocks back as
7204 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7205 * aligned range but not in the unaligned, original range are
7206 * put back to page allocator so that buddy can use them.
7207 */
7208
7209 ret = start_isolate_page_range(pfn_max_align_down(start),
7210 pfn_max_align_up(end), migratetype,
7211 false);
7212 if (ret)
7213 return ret;
7214
7215 /*
7216 * In case of -EBUSY, we'd like to know which page causes problem.
7217 * So, just fall through. We will check it in test_pages_isolated().
7218 */
7219 ret = __alloc_contig_migrate_range(&cc, start, end);
7220 if (ret && ret != -EBUSY)
7221 goto done;
7222
7223 /*
7224 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7225 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7226 * more, all pages in [start, end) are free in page allocator.
7227 * What we are going to do is to allocate all pages from
7228 * [start, end) (that is remove them from page allocator).
7229 *
7230 * The only problem is that pages at the beginning and at the
7231 * end of interesting range may be not aligned with pages that
7232 * page allocator holds, ie. they can be part of higher order
7233 * pages. Because of this, we reserve the bigger range and
7234 * once this is done free the pages we are not interested in.
7235 *
7236 * We don't have to hold zone->lock here because the pages are
7237 * isolated thus they won't get removed from buddy.
7238 */
7239
7240 lru_add_drain_all();
7241 drain_all_pages(cc.zone);
7242
7243 order = 0;
7244 outer_start = start;
7245 while (!PageBuddy(pfn_to_page(outer_start))) {
7246 if (++order >= MAX_ORDER) {
7247 outer_start = start;
7248 break;
7249 }
7250 outer_start &= ~0UL << order;
7251 }
7252
7253 if (outer_start != start) {
7254 order = page_order(pfn_to_page(outer_start));
7255
7256 /*
7257 * outer_start page could be small order buddy page and
7258 * it doesn't include start page. Adjust outer_start
7259 * in this case to report failed page properly
7260 * on tracepoint in test_pages_isolated()
7261 */
7262 if (outer_start + (1UL << order) <= start)
7263 outer_start = start;
7264 }
7265
7266 /* Make sure the range is really isolated. */
7267 if (test_pages_isolated(outer_start, end, false)) {
7268 pr_info("%s: [%lx, %lx) PFNs busy\n",
7269 __func__, outer_start, end);
7270 ret = -EBUSY;
7271 goto done;
7272 }
7273
7274 /* Grab isolated pages from freelists. */
7275 outer_end = isolate_freepages_range(&cc, outer_start, end);
7276 if (!outer_end) {
7277 ret = -EBUSY;
7278 goto done;
7279 }
7280
7281 /* Free head and tail (if any) */
7282 if (start != outer_start)
7283 free_contig_range(outer_start, start - outer_start);
7284 if (end != outer_end)
7285 free_contig_range(end, outer_end - end);
7286
7287 done:
7288 undo_isolate_page_range(pfn_max_align_down(start),
7289 pfn_max_align_up(end), migratetype);
7290 return ret;
7291 }
7292
7293 void free_contig_range(unsigned long pfn, unsigned nr_pages)
7294 {
7295 unsigned int count = 0;
7296
7297 for (; nr_pages--; pfn++) {
7298 struct page *page = pfn_to_page(pfn);
7299
7300 count += page_count(page) != 1;
7301 __free_page(page);
7302 }
7303 WARN(count != 0, "%d pages are still in use!\n", count);
7304 }
7305 #endif
7306
7307 #ifdef CONFIG_MEMORY_HOTPLUG
7308 /*
7309 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7310 * page high values need to be recalulated.
7311 */
7312 void __meminit zone_pcp_update(struct zone *zone)
7313 {
7314 unsigned cpu;
7315 mutex_lock(&pcp_batch_high_lock);
7316 for_each_possible_cpu(cpu)
7317 pageset_set_high_and_batch(zone,
7318 per_cpu_ptr(zone->pageset, cpu));
7319 mutex_unlock(&pcp_batch_high_lock);
7320 }
7321 #endif
7322
7323 void zone_pcp_reset(struct zone *zone)
7324 {
7325 unsigned long flags;
7326 int cpu;
7327 struct per_cpu_pageset *pset;
7328
7329 /* avoid races with drain_pages() */
7330 local_irq_save(flags);
7331 if (zone->pageset != &boot_pageset) {
7332 for_each_online_cpu(cpu) {
7333 pset = per_cpu_ptr(zone->pageset, cpu);
7334 drain_zonestat(zone, pset);
7335 }
7336 free_percpu(zone->pageset);
7337 zone->pageset = &boot_pageset;
7338 }
7339 local_irq_restore(flags);
7340 }
7341
7342 #ifdef CONFIG_MEMORY_HOTREMOVE
7343 /*
7344 * All pages in the range must be in a single zone and isolated
7345 * before calling this.
7346 */
7347 void
7348 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
7349 {
7350 struct page *page;
7351 struct zone *zone;
7352 unsigned int order, i;
7353 unsigned long pfn;
7354 unsigned long flags;
7355 /* find the first valid pfn */
7356 for (pfn = start_pfn; pfn < end_pfn; pfn++)
7357 if (pfn_valid(pfn))
7358 break;
7359 if (pfn == end_pfn)
7360 return;
7361 zone = page_zone(pfn_to_page(pfn));
7362 spin_lock_irqsave(&zone->lock, flags);
7363 pfn = start_pfn;
7364 while (pfn < end_pfn) {
7365 if (!pfn_valid(pfn)) {
7366 pfn++;
7367 continue;
7368 }
7369 page = pfn_to_page(pfn);
7370 /*
7371 * The HWPoisoned page may be not in buddy system, and
7372 * page_count() is not 0.
7373 */
7374 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
7375 pfn++;
7376 SetPageReserved(page);
7377 continue;
7378 }
7379
7380 BUG_ON(page_count(page));
7381 BUG_ON(!PageBuddy(page));
7382 order = page_order(page);
7383 #ifdef CONFIG_DEBUG_VM
7384 pr_info("remove from free list %lx %d %lx\n",
7385 pfn, 1 << order, end_pfn);
7386 #endif
7387 list_del(&page->lru);
7388 rmv_page_order(page);
7389 zone->free_area[order].nr_free--;
7390 for (i = 0; i < (1 << order); i++)
7391 SetPageReserved((page+i));
7392 pfn += (1 << order);
7393 }
7394 spin_unlock_irqrestore(&zone->lock, flags);
7395 }
7396 #endif
7397
7398 bool is_free_buddy_page(struct page *page)
7399 {
7400 struct zone *zone = page_zone(page);
7401 unsigned long pfn = page_to_pfn(page);
7402 unsigned long flags;
7403 unsigned int order;
7404
7405 spin_lock_irqsave(&zone->lock, flags);
7406 for (order = 0; order < MAX_ORDER; order++) {
7407 struct page *page_head = page - (pfn & ((1 << order) - 1));
7408
7409 if (PageBuddy(page_head) && page_order(page_head) >= order)
7410 break;
7411 }
7412 spin_unlock_irqrestore(&zone->lock, flags);
7413
7414 return order < MAX_ORDER;
7415 }
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