page_alloc.c 134.8 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
/*
 *  linux/mm/page_alloc.c
 *
 *  Manages the free list, the system allocates free pages here.
 *  Note that kmalloc() lives in slab.c
 *
 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *  Swap reorganised 29.12.95, Stephen Tweedie
 *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
 *  Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
 *  Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
 *  Zone balancing, Kanoj Sarcar, SGI, Jan 2000
 *  Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
 *          (lots of bits borrowed from Ingo Molnar & Andrew Morton)
 */

#include <linux/stddef.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/interrupt.h>
#include <linux/pagemap.h>
22
#include <linux/jiffies.h>
L
Linus Torvalds 已提交
23 24
#include <linux/bootmem.h>
#include <linux/compiler.h>
25
#include <linux/kernel.h>
26
#include <linux/kmemcheck.h>
L
Linus Torvalds 已提交
27 28 29 30 31
#include <linux/module.h>
#include <linux/suspend.h>
#include <linux/pagevec.h>
#include <linux/blkdev.h>
#include <linux/slab.h>
32
#include <linux/oom.h>
L
Linus Torvalds 已提交
33 34 35 36 37
#include <linux/notifier.h>
#include <linux/topology.h>
#include <linux/sysctl.h>
#include <linux/cpu.h>
#include <linux/cpuset.h>
38
#include <linux/memory_hotplug.h>
L
Linus Torvalds 已提交
39 40
#include <linux/nodemask.h>
#include <linux/vmalloc.h>
41
#include <linux/mempolicy.h>
42
#include <linux/stop_machine.h>
43 44
#include <linux/sort.h>
#include <linux/pfn.h>
45
#include <linux/backing-dev.h>
46
#include <linux/fault-inject.h>
K
KAMEZAWA Hiroyuki 已提交
47
#include <linux/page-isolation.h>
48
#include <linux/page_cgroup.h>
49
#include <linux/debugobjects.h>
50
#include <linux/kmemleak.h>
L
Linus Torvalds 已提交
51 52

#include <asm/tlbflush.h>
53
#include <asm/div64.h>
L
Linus Torvalds 已提交
54 55 56
#include "internal.h"

/*
57
 * Array of node states.
L
Linus Torvalds 已提交
58
 */
59 60 61 62 63 64 65 66 67 68 69 70 71
nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
	[N_POSSIBLE] = NODE_MASK_ALL,
	[N_ONLINE] = { { [0] = 1UL } },
#ifndef CONFIG_NUMA
	[N_NORMAL_MEMORY] = { { [0] = 1UL } },
#ifdef CONFIG_HIGHMEM
	[N_HIGH_MEMORY] = { { [0] = 1UL } },
#endif
	[N_CPU] = { { [0] = 1UL } },
#endif	/* NUMA */
};
EXPORT_SYMBOL(node_states);

72
unsigned long totalram_pages __read_mostly;
73
unsigned long totalreserve_pages __read_mostly;
74
unsigned long highest_memmap_pfn __read_mostly;
75
int percpu_pagelist_fraction;
76
gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
L
Linus Torvalds 已提交
77

78 79 80 81
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
int pageblock_order __read_mostly;
#endif

82
static void __free_pages_ok(struct page *page, unsigned int order);
83

L
Linus Torvalds 已提交
84 85 86 87 88 89 90
/*
 * results with 256, 32 in the lowmem_reserve sysctl:
 *	1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
 *	1G machine -> (16M dma, 784M normal, 224M high)
 *	NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
 *	HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
 *	HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
A
Andi Kleen 已提交
91 92 93
 *
 * TBD: should special case ZONE_DMA32 machines here - in those we normally
 * don't need any ZONE_NORMAL reservation
L
Linus Torvalds 已提交
94
 */
95
int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
96
#ifdef CONFIG_ZONE_DMA
97
	 256,
98
#endif
99
#ifdef CONFIG_ZONE_DMA32
100
	 256,
101
#endif
102
#ifdef CONFIG_HIGHMEM
M
Mel Gorman 已提交
103
	 32,
104
#endif
M
Mel Gorman 已提交
105
	 32,
106
};
L
Linus Torvalds 已提交
107 108 109

EXPORT_SYMBOL(totalram_pages);

110
static char * const zone_names[MAX_NR_ZONES] = {
111
#ifdef CONFIG_ZONE_DMA
112
	 "DMA",
113
#endif
114
#ifdef CONFIG_ZONE_DMA32
115
	 "DMA32",
116
#endif
117
	 "Normal",
118
#ifdef CONFIG_HIGHMEM
M
Mel Gorman 已提交
119
	 "HighMem",
120
#endif
M
Mel Gorman 已提交
121
	 "Movable",
122 123
};

L
Linus Torvalds 已提交
124 125
int min_free_kbytes = 1024;

126 127
unsigned long __meminitdata nr_kernel_pages;
unsigned long __meminitdata nr_all_pages;
128
static unsigned long __meminitdata dma_reserve;
L
Linus Torvalds 已提交
129

130 131
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
  /*
S
Simon Arlott 已提交
132
   * MAX_ACTIVE_REGIONS determines the maximum number of distinct
133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150
   * ranges of memory (RAM) that may be registered with add_active_range().
   * Ranges passed to add_active_range() will be merged if possible
   * so the number of times add_active_range() can be called is
   * related to the number of nodes and the number of holes
   */
  #ifdef CONFIG_MAX_ACTIVE_REGIONS
    /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */
    #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS
  #else
    #if MAX_NUMNODES >= 32
      /* If there can be many nodes, allow up to 50 holes per node */
      #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50)
    #else
      /* By default, allow up to 256 distinct regions */
      #define MAX_ACTIVE_REGIONS 256
    #endif
  #endif

151 152 153 154
  static struct node_active_region __meminitdata early_node_map[MAX_ACTIVE_REGIONS];
  static int __meminitdata nr_nodemap_entries;
  static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
  static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
A
Adrian Bunk 已提交
155
  static unsigned long __initdata required_kernelcore;
A
Adrian Bunk 已提交
156
  static unsigned long __initdata required_movablecore;
A
Adrian Bunk 已提交
157
  static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
M
Mel Gorman 已提交
158 159 160 161

  /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
  int movable_zone;
  EXPORT_SYMBOL(movable_zone);
162 163
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */

M
Miklos Szeredi 已提交
164 165
#if MAX_NUMNODES > 1
int nr_node_ids __read_mostly = MAX_NUMNODES;
166
int nr_online_nodes __read_mostly = 1;
M
Miklos Szeredi 已提交
167
EXPORT_SYMBOL(nr_node_ids);
168
EXPORT_SYMBOL(nr_online_nodes);
M
Miklos Szeredi 已提交
169 170
#endif

171 172
int page_group_by_mobility_disabled __read_mostly;

173 174
static void set_pageblock_migratetype(struct page *page, int migratetype)
{
175 176 177 178

	if (unlikely(page_group_by_mobility_disabled))
		migratetype = MIGRATE_UNMOVABLE;

179 180 181 182
	set_pageblock_flags_group(page, (unsigned long)migratetype,
					PB_migrate, PB_migrate_end);
}

183 184
bool oom_killer_disabled __read_mostly;

N
Nick Piggin 已提交
185
#ifdef CONFIG_DEBUG_VM
186
static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
L
Linus Torvalds 已提交
187
{
188 189 190
	int ret = 0;
	unsigned seq;
	unsigned long pfn = page_to_pfn(page);
191

192 193 194 195 196 197 198 199 200
	do {
		seq = zone_span_seqbegin(zone);
		if (pfn >= zone->zone_start_pfn + zone->spanned_pages)
			ret = 1;
		else if (pfn < zone->zone_start_pfn)
			ret = 1;
	} while (zone_span_seqretry(zone, seq));

	return ret;
201 202 203 204
}

static int page_is_consistent(struct zone *zone, struct page *page)
{
205
	if (!pfn_valid_within(page_to_pfn(page)))
206
		return 0;
L
Linus Torvalds 已提交
207
	if (zone != page_zone(page))
208 209 210 211 212 213 214 215 216 217
		return 0;

	return 1;
}
/*
 * Temporary debugging check for pages not lying within a given zone.
 */
static int bad_range(struct zone *zone, struct page *page)
{
	if (page_outside_zone_boundaries(zone, page))
L
Linus Torvalds 已提交
218
		return 1;
219 220 221
	if (!page_is_consistent(zone, page))
		return 1;

L
Linus Torvalds 已提交
222 223
	return 0;
}
N
Nick Piggin 已提交
224 225 226 227 228 229 230
#else
static inline int bad_range(struct zone *zone, struct page *page)
{
	return 0;
}
#endif

N
Nick Piggin 已提交
231
static void bad_page(struct page *page)
L
Linus Torvalds 已提交
232
{
233 234 235 236 237 238 239 240 241 242 243 244 245 246
	static unsigned long resume;
	static unsigned long nr_shown;
	static unsigned long nr_unshown;

	/*
	 * Allow a burst of 60 reports, then keep quiet for that minute;
	 * or allow a steady drip of one report per second.
	 */
	if (nr_shown == 60) {
		if (time_before(jiffies, resume)) {
			nr_unshown++;
			goto out;
		}
		if (nr_unshown) {
247 248
			printk(KERN_ALERT
			      "BUG: Bad page state: %lu messages suppressed\n",
249 250 251 252 253 254 255 256
				nr_unshown);
			nr_unshown = 0;
		}
		nr_shown = 0;
	}
	if (nr_shown++ == 0)
		resume = jiffies + 60 * HZ;

257
	printk(KERN_ALERT "BUG: Bad page state in process %s  pfn:%05lx\n",
258
		current->comm, page_to_pfn(page));
259
	printk(KERN_ALERT
260 261 262 263
		"page:%p flags:%p count:%d mapcount:%d mapping:%p index:%lx\n",
		page, (void *)page->flags, page_count(page),
		page_mapcount(page), page->mapping, page->index);

L
Linus Torvalds 已提交
264
	dump_stack();
265
out:
266 267
	/* Leave bad fields for debug, except PageBuddy could make trouble */
	__ClearPageBuddy(page);
268
	add_taint(TAINT_BAD_PAGE);
L
Linus Torvalds 已提交
269 270 271 272 273 274 275 276 277 278 279 280
}

/*
 * Higher-order pages are called "compound pages".  They are structured thusly:
 *
 * The first PAGE_SIZE page is called the "head page".
 *
 * The remaining PAGE_SIZE pages are called "tail pages".
 *
 * All pages have PG_compound set.  All pages have their ->private pointing at
 * the head page (even the head page has this).
 *
281 282 283
 * The first tail page's ->lru.next holds the address of the compound page's
 * put_page() function.  Its ->lru.prev holds the order of allocation.
 * This usage means that zero-order pages may not be compound.
L
Linus Torvalds 已提交
284
 */
285 286 287

static void free_compound_page(struct page *page)
{
288
	__free_pages_ok(page, compound_order(page));
289 290
}

A
Andi Kleen 已提交
291
void prep_compound_page(struct page *page, unsigned long order)
292 293 294 295 296 297 298 299 300 301 302 303 304 305 306
{
	int i;
	int nr_pages = 1 << order;

	set_compound_page_dtor(page, free_compound_page);
	set_compound_order(page, order);
	__SetPageHead(page);
	for (i = 1; i < nr_pages; i++) {
		struct page *p = page + i;

		__SetPageTail(p);
		p->first_page = page;
	}
}

307
static int destroy_compound_page(struct page *page, unsigned long order)
L
Linus Torvalds 已提交
308 309 310
{
	int i;
	int nr_pages = 1 << order;
311
	int bad = 0;
L
Linus Torvalds 已提交
312

313 314
	if (unlikely(compound_order(page) != order) ||
	    unlikely(!PageHead(page))) {
N
Nick Piggin 已提交
315
		bad_page(page);
316 317
		bad++;
	}
L
Linus Torvalds 已提交
318

319
	__ClearPageHead(page);
320

321 322
	for (i = 1; i < nr_pages; i++) {
		struct page *p = page + i;
L
Linus Torvalds 已提交
323

324
		if (unlikely(!PageTail(p) || (p->first_page != page))) {
N
Nick Piggin 已提交
325
			bad_page(page);
326 327
			bad++;
		}
328
		__ClearPageTail(p);
L
Linus Torvalds 已提交
329
	}
330 331

	return bad;
L
Linus Torvalds 已提交
332 333
}

N
Nick Piggin 已提交
334 335 336 337
static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
{
	int i;

338 339 340 341
	/*
	 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
	 * and __GFP_HIGHMEM from hard or soft interrupt context.
	 */
N
Nick Piggin 已提交
342
	VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt());
N
Nick Piggin 已提交
343 344 345 346
	for (i = 0; i < (1 << order); i++)
		clear_highpage(page + i);
}

347 348
static inline void set_page_order(struct page *page, int order)
{
H
Hugh Dickins 已提交
349
	set_page_private(page, order);
350
	__SetPageBuddy(page);
L
Linus Torvalds 已提交
351 352 353 354
}

static inline void rmv_page_order(struct page *page)
{
355
	__ClearPageBuddy(page);
H
Hugh Dickins 已提交
356
	set_page_private(page, 0);
L
Linus Torvalds 已提交
357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373
}

/*
 * Locate the struct page for both the matching buddy in our
 * pair (buddy1) and the combined O(n+1) page they form (page).
 *
 * 1) Any buddy B1 will have an order O twin B2 which satisfies
 * the following equation:
 *     B2 = B1 ^ (1 << O)
 * For example, if the starting buddy (buddy2) is #8 its order
 * 1 buddy is #10:
 *     B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
 *
 * 2) Any buddy B will have an order O+1 parent P which
 * satisfies the following equation:
 *     P = B & ~(1 << O)
 *
A
Andreas Mohr 已提交
374
 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
L
Linus Torvalds 已提交
375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392
 */
static inline struct page *
__page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order)
{
	unsigned long buddy_idx = page_idx ^ (1 << order);

	return page + (buddy_idx - page_idx);
}

static inline unsigned long
__find_combined_index(unsigned long page_idx, unsigned int order)
{
	return (page_idx & ~(1 << order));
}

/*
 * This function checks whether a page is free && is the buddy
 * we can do coalesce a page and its buddy if
N
Nick Piggin 已提交
393
 * (a) the buddy is not in a hole &&
394
 * (b) the buddy is in the buddy system &&
395 396
 * (c) a page and its buddy have the same order &&
 * (d) a page and its buddy are in the same zone.
397 398 399
 *
 * For recording whether a page is in the buddy system, we use PG_buddy.
 * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
L
Linus Torvalds 已提交
400
 *
401
 * For recording page's order, we use page_private(page).
L
Linus Torvalds 已提交
402
 */
403 404
static inline int page_is_buddy(struct page *page, struct page *buddy,
								int order)
L
Linus Torvalds 已提交
405
{
406
	if (!pfn_valid_within(page_to_pfn(buddy)))
N
Nick Piggin 已提交
407 408
		return 0;

409 410 411 412
	if (page_zone_id(page) != page_zone_id(buddy))
		return 0;

	if (PageBuddy(buddy) && page_order(buddy) == order) {
413
		VM_BUG_ON(page_count(buddy) != 0);
414
		return 1;
415
	}
416
	return 0;
L
Linus Torvalds 已提交
417 418 419 420 421 422 423 424 425 426 427 428 429 430 431
}

/*
 * Freeing function for a buddy system allocator.
 *
 * The concept of a buddy system is to maintain direct-mapped table
 * (containing bit values) for memory blocks of various "orders".
 * The bottom level table contains the map for the smallest allocatable
 * units of memory (here, pages), and each level above it describes
 * pairs of units from the levels below, hence, "buddies".
 * At a high level, all that happens here is marking the table entry
 * at the bottom level available, and propagating the changes upward
 * as necessary, plus some accounting needed to play nicely with other
 * parts of the VM system.
 * At each level, we keep a list of pages, which are heads of continuous
432
 * free pages of length of (1 << order) and marked with PG_buddy. Page's
H
Hugh Dickins 已提交
433
 * order is recorded in page_private(page) field.
L
Linus Torvalds 已提交
434 435 436 437 438 439 440 441 442
 * So when we are allocating or freeing one, we can derive the state of the
 * other.  That is, if we allocate a small block, and both were   
 * free, the remainder of the region must be split into blocks.   
 * If a block is freed, and its buddy is also free, then this
 * triggers coalescing into a block of larger size.            
 *
 * -- wli
 */

N
Nick Piggin 已提交
443
static inline void __free_one_page(struct page *page,
444 445
		struct zone *zone, unsigned int order,
		int migratetype)
L
Linus Torvalds 已提交
446 447 448
{
	unsigned long page_idx;

N
Nick Piggin 已提交
449
	if (unlikely(PageCompound(page)))
450 451
		if (unlikely(destroy_compound_page(page, order)))
			return;
L
Linus Torvalds 已提交
452

453 454
	VM_BUG_ON(migratetype == -1);

L
Linus Torvalds 已提交
455 456
	page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);

457
	VM_BUG_ON(page_idx & ((1 << order) - 1));
N
Nick Piggin 已提交
458
	VM_BUG_ON(bad_range(zone, page));
L
Linus Torvalds 已提交
459 460 461 462 463 464

	while (order < MAX_ORDER-1) {
		unsigned long combined_idx;
		struct page *buddy;

		buddy = __page_find_buddy(page, page_idx, order);
465
		if (!page_is_buddy(page, buddy, order))
466
			break;
N
Nick Piggin 已提交
467

468
		/* Our buddy is free, merge with it and move up one order. */
L
Linus Torvalds 已提交
469
		list_del(&buddy->lru);
470
		zone->free_area[order].nr_free--;
L
Linus Torvalds 已提交
471
		rmv_page_order(buddy);
N
Nick Piggin 已提交
472
		combined_idx = __find_combined_index(page_idx, order);
L
Linus Torvalds 已提交
473 474 475 476 477
		page = page + (combined_idx - page_idx);
		page_idx = combined_idx;
		order++;
	}
	set_page_order(page, order);
478 479
	list_add(&page->lru,
		&zone->free_area[order].free_list[migratetype]);
L
Linus Torvalds 已提交
480 481 482
	zone->free_area[order].nr_free++;
}

483 484 485 486 487 488 489 490 491 492 493 494 495 496 497
#ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT
/*
 * free_page_mlock() -- clean up attempts to free and mlocked() page.
 * Page should not be on lru, so no need to fix that up.
 * free_pages_check() will verify...
 */
static inline void free_page_mlock(struct page *page)
{
	__dec_zone_page_state(page, NR_MLOCK);
	__count_vm_event(UNEVICTABLE_MLOCKFREED);
}
#else
static void free_page_mlock(struct page *page) { }
#endif

N
Nick Piggin 已提交
498
static inline int free_pages_check(struct page *page)
L
Linus Torvalds 已提交
499
{
N
Nick Piggin 已提交
500 501
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
502
		(atomic_read(&page->_count) != 0) |
503
		(page->flags & PAGE_FLAGS_CHECK_AT_FREE))) {
N
Nick Piggin 已提交
504
		bad_page(page);
505
		return 1;
506
	}
507 508 509
	if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
		page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
	return 0;
L
Linus Torvalds 已提交
510 511 512 513 514
}

/*
 * Frees a list of pages. 
 * Assumes all pages on list are in same zone, and of same order.
515
 * count is the number of pages to free.
L
Linus Torvalds 已提交
516 517 518 519 520 521 522
 *
 * If the zone was previously in an "all pages pinned" state then look to
 * see if this freeing clears that state.
 *
 * And clear the zone's pages_scanned counter, to hold off the "all pages are
 * pinned" detection logic.
 */
N
Nick Piggin 已提交
523 524
static void free_pages_bulk(struct zone *zone, int count,
					struct list_head *list, int order)
L
Linus Torvalds 已提交
525
{
N
Nick Piggin 已提交
526
	spin_lock(&zone->lock);
527
	zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
L
Linus Torvalds 已提交
528
	zone->pages_scanned = 0;
529 530

	__mod_zone_page_state(zone, NR_FREE_PAGES, count << order);
N
Nick Piggin 已提交
531 532 533
	while (count--) {
		struct page *page;

N
Nick Piggin 已提交
534
		VM_BUG_ON(list_empty(list));
L
Linus Torvalds 已提交
535
		page = list_entry(list->prev, struct page, lru);
N
Nick Piggin 已提交
536
		/* have to delete it as __free_one_page list manipulates */
L
Linus Torvalds 已提交
537
		list_del(&page->lru);
538
		__free_one_page(page, zone, order, page_private(page));
L
Linus Torvalds 已提交
539
	}
N
Nick Piggin 已提交
540
	spin_unlock(&zone->lock);
L
Linus Torvalds 已提交
541 542
}

543 544
static void free_one_page(struct zone *zone, struct page *page, int order,
				int migratetype)
L
Linus Torvalds 已提交
545
{
546
	spin_lock(&zone->lock);
547
	zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
548
	zone->pages_scanned = 0;
549 550

	__mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
551
	__free_one_page(page, zone, order, migratetype);
552
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
553 554 555 556 557
}

static void __free_pages_ok(struct page *page, unsigned int order)
{
	unsigned long flags;
L
Linus Torvalds 已提交
558
	int i;
559
	int bad = 0;
560
	int wasMlocked = TestClearPageMlocked(page);
L
Linus Torvalds 已提交
561

562 563
	kmemcheck_free_shadow(page, order);

L
Linus Torvalds 已提交
564
	for (i = 0 ; i < (1 << order) ; ++i)
565 566
		bad += free_pages_check(page + i);
	if (bad)
567 568
		return;

569
	if (!PageHighMem(page)) {
N
Nick Piggin 已提交
570
		debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
571 572 573
		debug_check_no_obj_freed(page_address(page),
					   PAGE_SIZE << order);
	}
N
Nick Piggin 已提交
574
	arch_free_page(page, order);
N
Nick Piggin 已提交
575
	kernel_map_pages(page, 1 << order, 0);
N
Nick Piggin 已提交
576

N
Nick Piggin 已提交
577
	local_irq_save(flags);
578
	if (unlikely(wasMlocked))
579
		free_page_mlock(page);
580
	__count_vm_events(PGFREE, 1 << order);
581 582
	free_one_page(page_zone(page), page, order,
					get_pageblock_migratetype(page));
N
Nick Piggin 已提交
583
	local_irq_restore(flags);
L
Linus Torvalds 已提交
584 585
}

586 587 588
/*
 * permit the bootmem allocator to evade page validation on high-order frees
 */
589
void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
590 591 592 593
{
	if (order == 0) {
		__ClearPageReserved(page);
		set_page_count(page, 0);
594
		set_page_refcounted(page);
N
Nick Piggin 已提交
595
		__free_page(page);
596 597 598
	} else {
		int loop;

N
Nick Piggin 已提交
599
		prefetchw(page);
600 601 602
		for (loop = 0; loop < BITS_PER_LONG; loop++) {
			struct page *p = &page[loop];

N
Nick Piggin 已提交
603 604
			if (loop + 1 < BITS_PER_LONG)
				prefetchw(p + 1);
605 606 607 608
			__ClearPageReserved(p);
			set_page_count(p, 0);
		}

609
		set_page_refcounted(page);
N
Nick Piggin 已提交
610
		__free_pages(page, order);
611 612 613
	}
}

L
Linus Torvalds 已提交
614 615 616 617 618 619 620 621 622 623 624 625 626 627 628

/*
 * The order of subdivision here is critical for the IO subsystem.
 * Please do not alter this order without good reasons and regression
 * testing. Specifically, as large blocks of memory are subdivided,
 * the order in which smaller blocks are delivered depends on the order
 * they're subdivided in this function. This is the primary factor
 * influencing the order in which pages are delivered to the IO
 * subsystem according to empirical testing, and this is also justified
 * by considering the behavior of a buddy system containing a single
 * large block of memory acted on by a series of small allocations.
 * This behavior is a critical factor in sglist merging's success.
 *
 * -- wli
 */
N
Nick Piggin 已提交
629
static inline void expand(struct zone *zone, struct page *page,
630 631
	int low, int high, struct free_area *area,
	int migratetype)
L
Linus Torvalds 已提交
632 633 634 635 636 637 638
{
	unsigned long size = 1 << high;

	while (high > low) {
		area--;
		high--;
		size >>= 1;
N
Nick Piggin 已提交
639
		VM_BUG_ON(bad_range(zone, &page[size]));
640
		list_add(&page[size].lru, &area->free_list[migratetype]);
L
Linus Torvalds 已提交
641 642 643 644 645 646 647 648
		area->nr_free++;
		set_page_order(&page[size], high);
	}
}

/*
 * This page is about to be returned from the page allocator
 */
N
Nick Piggin 已提交
649
static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
L
Linus Torvalds 已提交
650
{
N
Nick Piggin 已提交
651 652
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
653
		(atomic_read(&page->_count) != 0)  |
654
		(page->flags & PAGE_FLAGS_CHECK_AT_PREP))) {
N
Nick Piggin 已提交
655
		bad_page(page);
656
		return 1;
657
	}
658

H
Hugh Dickins 已提交
659
	set_page_private(page, 0);
660
	set_page_refcounted(page);
N
Nick Piggin 已提交
661 662

	arch_alloc_page(page, order);
L
Linus Torvalds 已提交
663
	kernel_map_pages(page, 1 << order, 1);
N
Nick Piggin 已提交
664 665 666 667 668 669 670

	if (gfp_flags & __GFP_ZERO)
		prep_zero_page(page, order, gfp_flags);

	if (order && (gfp_flags & __GFP_COMP))
		prep_compound_page(page, order);

671
	return 0;
L
Linus Torvalds 已提交
672 673
}

674 675 676 677
/*
 * Go through the free lists for the given migratetype and remove
 * the smallest available page from the freelists
 */
678 679
static inline
struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704
						int migratetype)
{
	unsigned int current_order;
	struct free_area * area;
	struct page *page;

	/* Find a page of the appropriate size in the preferred list */
	for (current_order = order; current_order < MAX_ORDER; ++current_order) {
		area = &(zone->free_area[current_order]);
		if (list_empty(&area->free_list[migratetype]))
			continue;

		page = list_entry(area->free_list[migratetype].next,
							struct page, lru);
		list_del(&page->lru);
		rmv_page_order(page);
		area->nr_free--;
		expand(zone, page, order, current_order, area, migratetype);
		return page;
	}

	return NULL;
}


705 706 707 708 709
/*
 * This array describes the order lists are fallen back to when
 * the free lists for the desirable migrate type are depleted
 */
static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = {
710 711 712 713
	[MIGRATE_UNMOVABLE]   = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE,   MIGRATE_RESERVE },
	[MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE,   MIGRATE_MOVABLE,   MIGRATE_RESERVE },
	[MIGRATE_MOVABLE]     = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
	[MIGRATE_RESERVE]     = { MIGRATE_RESERVE,     MIGRATE_RESERVE,   MIGRATE_RESERVE }, /* Never used */
714 715
};

716 717
/*
 * Move the free pages in a range to the free lists of the requested type.
718
 * Note that start_page and end_pages are not aligned on a pageblock
719 720
 * boundary. If alignment is required, use move_freepages_block()
 */
A
Adrian Bunk 已提交
721 722 723
static int move_freepages(struct zone *zone,
			  struct page *start_page, struct page *end_page,
			  int migratetype)
724 725 726
{
	struct page *page;
	unsigned long order;
727
	int pages_moved = 0;
728 729 730 731 732 733 734

#ifndef CONFIG_HOLES_IN_ZONE
	/*
	 * page_zone is not safe to call in this context when
	 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
	 * anyway as we check zone boundaries in move_freepages_block().
	 * Remove at a later date when no bug reports exist related to
M
Mel Gorman 已提交
735
	 * grouping pages by mobility
736 737 738 739 740
	 */
	BUG_ON(page_zone(start_page) != page_zone(end_page));
#endif

	for (page = start_page; page <= end_page;) {
741 742 743
		/* Make sure we are not inadvertently changing nodes */
		VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));

744 745 746 747 748 749 750 751 752 753 754 755 756 757 758
		if (!pfn_valid_within(page_to_pfn(page))) {
			page++;
			continue;
		}

		if (!PageBuddy(page)) {
			page++;
			continue;
		}

		order = page_order(page);
		list_del(&page->lru);
		list_add(&page->lru,
			&zone->free_area[order].free_list[migratetype]);
		page += 1 << order;
759
		pages_moved += 1 << order;
760 761
	}

762
	return pages_moved;
763 764
}

A
Adrian Bunk 已提交
765 766
static int move_freepages_block(struct zone *zone, struct page *page,
				int migratetype)
767 768 769 770 771
{
	unsigned long start_pfn, end_pfn;
	struct page *start_page, *end_page;

	start_pfn = page_to_pfn(page);
772
	start_pfn = start_pfn & ~(pageblock_nr_pages-1);
773
	start_page = pfn_to_page(start_pfn);
774 775
	end_page = start_page + pageblock_nr_pages - 1;
	end_pfn = start_pfn + pageblock_nr_pages - 1;
776 777 778 779 780 781 782 783 784 785

	/* Do not cross zone boundaries */
	if (start_pfn < zone->zone_start_pfn)
		start_page = page;
	if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages)
		return 0;

	return move_freepages(zone, start_page, end_page, migratetype);
}

786
/* Remove an element from the buddy allocator from the fallback list */
787 788
static inline struct page *
__rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
789 790 791 792 793 794 795 796 797 798 799 800
{
	struct free_area * area;
	int current_order;
	struct page *page;
	int migratetype, i;

	/* Find the largest possible block of pages in the other list */
	for (current_order = MAX_ORDER-1; current_order >= order;
						--current_order) {
		for (i = 0; i < MIGRATE_TYPES - 1; i++) {
			migratetype = fallbacks[start_migratetype][i];

801 802 803
			/* MIGRATE_RESERVE handled later if necessary */
			if (migratetype == MIGRATE_RESERVE)
				continue;
M
Mel Gorman 已提交
804

805 806 807 808 809 810 811 812 813
			area = &(zone->free_area[current_order]);
			if (list_empty(&area->free_list[migratetype]))
				continue;

			page = list_entry(area->free_list[migratetype].next,
					struct page, lru);
			area->nr_free--;

			/*
814
			 * If breaking a large block of pages, move all free
815 816 817
			 * pages to the preferred allocation list. If falling
			 * back for a reclaimable kernel allocation, be more
			 * agressive about taking ownership of free pages
818
			 */
819
			if (unlikely(current_order >= (pageblock_order >> 1)) ||
820 821 822 823 824 825
					start_migratetype == MIGRATE_RECLAIMABLE) {
				unsigned long pages;
				pages = move_freepages_block(zone, page,
								start_migratetype);

				/* Claim the whole block if over half of it is free */
826
				if (pages >= (1 << (pageblock_order-1)))
827 828 829
					set_pageblock_migratetype(page,
								start_migratetype);

830
				migratetype = start_migratetype;
831
			}
832 833 834 835 836

			/* Remove the page from the freelists */
			list_del(&page->lru);
			rmv_page_order(page);

837
			if (current_order == pageblock_order)
838 839 840 841 842 843 844 845
				set_pageblock_migratetype(page,
							start_migratetype);

			expand(zone, page, order, current_order, area, migratetype);
			return page;
		}
	}

846
	return NULL;
847 848
}

849
/*
L
Linus Torvalds 已提交
850 851 852
 * Do the hard work of removing an element from the buddy allocator.
 * Call me with the zone->lock already held.
 */
853 854
static struct page *__rmqueue(struct zone *zone, unsigned int order,
						int migratetype)
L
Linus Torvalds 已提交
855 856 857
{
	struct page *page;

858
retry_reserve:
859
	page = __rmqueue_smallest(zone, order, migratetype);
860

861
	if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
862
		page = __rmqueue_fallback(zone, order, migratetype);
863

864 865 866 867 868 869 870 871 872 873 874
		/*
		 * Use MIGRATE_RESERVE rather than fail an allocation. goto
		 * is used because __rmqueue_smallest is an inline function
		 * and we want just one call site
		 */
		if (!page) {
			migratetype = MIGRATE_RESERVE;
			goto retry_reserve;
		}
	}

875
	return page;
L
Linus Torvalds 已提交
876 877 878 879 880 881 882 883
}

/* 
 * Obtain a specified number of elements from the buddy allocator, all under
 * a single hold of the lock, for efficiency.  Add them to the supplied list.
 * Returns the number of new pages which were placed at *list.
 */
static int rmqueue_bulk(struct zone *zone, unsigned int order, 
884
			unsigned long count, struct list_head *list,
885
			int migratetype, int cold)
L
Linus Torvalds 已提交
886 887 888
{
	int i;
	
N
Nick Piggin 已提交
889
	spin_lock(&zone->lock);
L
Linus Torvalds 已提交
890
	for (i = 0; i < count; ++i) {
891
		struct page *page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
892
		if (unlikely(page == NULL))
L
Linus Torvalds 已提交
893
			break;
894 895 896 897 898 899 900 901 902 903

		/*
		 * Split buddy pages returned by expand() are received here
		 * in physical page order. The page is added to the callers and
		 * list and the list head then moves forward. From the callers
		 * perspective, the linked list is ordered by page number in
		 * some conditions. This is useful for IO devices that can
		 * merge IO requests if the physical pages are ordered
		 * properly.
		 */
904 905 906 907
		if (likely(cold == 0))
			list_add(&page->lru, list);
		else
			list_add_tail(&page->lru, list);
908
		set_page_private(page, migratetype);
909
		list = &page->lru;
L
Linus Torvalds 已提交
910
	}
911
	__mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
N
Nick Piggin 已提交
912
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
913
	return i;
L
Linus Torvalds 已提交
914 915
}

916
#ifdef CONFIG_NUMA
917
/*
918 919 920 921
 * Called from the vmstat counter updater to drain pagesets of this
 * currently executing processor on remote nodes after they have
 * expired.
 *
922 923
 * Note that this function must be called with the thread pinned to
 * a single processor.
924
 */
925
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
926 927
{
	unsigned long flags;
928
	int to_drain;
929

930 931 932 933 934 935 936 937
	local_irq_save(flags);
	if (pcp->count >= pcp->batch)
		to_drain = pcp->batch;
	else
		to_drain = pcp->count;
	free_pages_bulk(zone, to_drain, &pcp->list, 0);
	pcp->count -= to_drain;
	local_irq_restore(flags);
938 939 940
}
#endif

941 942 943 944 945 946 947 948
/*
 * Drain pages of the indicated processor.
 *
 * The processor must either be the current processor and the
 * thread pinned to the current processor or a processor that
 * is not online.
 */
static void drain_pages(unsigned int cpu)
L
Linus Torvalds 已提交
949
{
N
Nick Piggin 已提交
950
	unsigned long flags;
L
Linus Torvalds 已提交
951 952
	struct zone *zone;

953
	for_each_populated_zone(zone) {
L
Linus Torvalds 已提交
954
		struct per_cpu_pageset *pset;
955
		struct per_cpu_pages *pcp;
L
Linus Torvalds 已提交
956

957
		pset = zone_pcp(zone, cpu);
958 959 960 961 962 963

		pcp = &pset->pcp;
		local_irq_save(flags);
		free_pages_bulk(zone, pcp->count, &pcp->list, 0);
		pcp->count = 0;
		local_irq_restore(flags);
L
Linus Torvalds 已提交
964 965 966
	}
}

967 968 969 970 971 972 973 974 975 976 977 978 979
/*
 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
 */
void drain_local_pages(void *arg)
{
	drain_pages(smp_processor_id());
}

/*
 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
 */
void drain_all_pages(void)
{
980
	on_each_cpu(drain_local_pages, NULL, 1);
981 982
}

983
#ifdef CONFIG_HIBERNATION
L
Linus Torvalds 已提交
984 985 986

void mark_free_pages(struct zone *zone)
{
987 988
	unsigned long pfn, max_zone_pfn;
	unsigned long flags;
989
	int order, t;
L
Linus Torvalds 已提交
990 991 992 993 994 995
	struct list_head *curr;

	if (!zone->spanned_pages)
		return;

	spin_lock_irqsave(&zone->lock, flags);
996 997 998 999 1000 1001

	max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
	for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
		if (pfn_valid(pfn)) {
			struct page *page = pfn_to_page(pfn);

1002 1003
			if (!swsusp_page_is_forbidden(page))
				swsusp_unset_page_free(page);
1004
		}
L
Linus Torvalds 已提交
1005

1006 1007
	for_each_migratetype_order(order, t) {
		list_for_each(curr, &zone->free_area[order].free_list[t]) {
1008
			unsigned long i;
L
Linus Torvalds 已提交
1009

1010 1011
			pfn = page_to_pfn(list_entry(curr, struct page, lru));
			for (i = 0; i < (1UL << order); i++)
1012
				swsusp_set_page_free(pfn_to_page(pfn + i));
1013
		}
1014
	}
L
Linus Torvalds 已提交
1015 1016
	spin_unlock_irqrestore(&zone->lock, flags);
}
1017
#endif /* CONFIG_PM */
L
Linus Torvalds 已提交
1018 1019 1020 1021

/*
 * Free a 0-order page
 */
H
Harvey Harrison 已提交
1022
static void free_hot_cold_page(struct page *page, int cold)
L
Linus Torvalds 已提交
1023 1024 1025 1026
{
	struct zone *zone = page_zone(page);
	struct per_cpu_pages *pcp;
	unsigned long flags;
1027
	int wasMlocked = TestClearPageMlocked(page);
L
Linus Torvalds 已提交
1028

1029 1030
	kmemcheck_free_shadow(page, 0);

L
Linus Torvalds 已提交
1031 1032
	if (PageAnon(page))
		page->mapping = NULL;
N
Nick Piggin 已提交
1033
	if (free_pages_check(page))
1034 1035
		return;

1036
	if (!PageHighMem(page)) {
N
Nick Piggin 已提交
1037
		debug_check_no_locks_freed(page_address(page), PAGE_SIZE);
1038 1039
		debug_check_no_obj_freed(page_address(page), PAGE_SIZE);
	}
N
Nick Piggin 已提交
1040
	arch_free_page(page, 0);
1041 1042
	kernel_map_pages(page, 1, 0);

1043
	pcp = &zone_pcp(zone, get_cpu())->pcp;
1044
	set_page_private(page, get_pageblock_migratetype(page));
L
Linus Torvalds 已提交
1045
	local_irq_save(flags);
1046
	if (unlikely(wasMlocked))
1047
		free_page_mlock(page);
1048
	__count_vm_event(PGFREE);
1049

1050 1051 1052 1053
	if (cold)
		list_add_tail(&page->lru, &pcp->list);
	else
		list_add(&page->lru, &pcp->list);
L
Linus Torvalds 已提交
1054
	pcp->count++;
N
Nick Piggin 已提交
1055 1056 1057 1058
	if (pcp->count >= pcp->high) {
		free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
		pcp->count -= pcp->batch;
	}
L
Linus Torvalds 已提交
1059 1060 1061 1062
	local_irq_restore(flags);
	put_cpu();
}

H
Harvey Harrison 已提交
1063
void free_hot_page(struct page *page)
L
Linus Torvalds 已提交
1064 1065 1066 1067
{
	free_hot_cold_page(page, 0);
}
	
H
Harvey Harrison 已提交
1068
void free_cold_page(struct page *page)
L
Linus Torvalds 已提交
1069 1070 1071 1072
{
	free_hot_cold_page(page, 1);
}

N
Nick Piggin 已提交
1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084
/*
 * split_page takes a non-compound higher-order page, and splits it into
 * n (1<<order) sub-pages: page[0..n]
 * Each sub-page must be freed individually.
 *
 * Note: this is probably too low level an operation for use in drivers.
 * Please consult with lkml before using this in your driver.
 */
void split_page(struct page *page, unsigned int order)
{
	int i;

N
Nick Piggin 已提交
1085 1086
	VM_BUG_ON(PageCompound(page));
	VM_BUG_ON(!page_count(page));
1087 1088 1089 1090 1091 1092 1093 1094 1095 1096

#ifdef CONFIG_KMEMCHECK
	/*
	 * Split shadow pages too, because free(page[0]) would
	 * otherwise free the whole shadow.
	 */
	if (kmemcheck_page_is_tracked(page))
		split_page(virt_to_page(page[0].shadow), order);
#endif

1097 1098
	for (i = 1; i < (1 << order); i++)
		set_page_refcounted(page + i);
N
Nick Piggin 已提交
1099 1100
}

L
Linus Torvalds 已提交
1101 1102 1103 1104 1105
/*
 * Really, prep_compound_page() should be called from __rmqueue_bulk().  But
 * we cheat by calling it from here, in the order > 0 path.  Saves a branch
 * or two.
 */
1106 1107
static inline
struct page *buffered_rmqueue(struct zone *preferred_zone,
1108 1109
			struct zone *zone, int order, gfp_t gfp_flags,
			int migratetype)
L
Linus Torvalds 已提交
1110 1111
{
	unsigned long flags;
1112
	struct page *page;
L
Linus Torvalds 已提交
1113
	int cold = !!(gfp_flags & __GFP_COLD);
N
Nick Piggin 已提交
1114
	int cpu;
L
Linus Torvalds 已提交
1115

1116
again:
N
Nick Piggin 已提交
1117
	cpu  = get_cpu();
N
Nick Piggin 已提交
1118
	if (likely(order == 0)) {
L
Linus Torvalds 已提交
1119 1120
		struct per_cpu_pages *pcp;

1121
		pcp = &zone_pcp(zone, cpu)->pcp;
L
Linus Torvalds 已提交
1122
		local_irq_save(flags);
N
Nick Piggin 已提交
1123
		if (!pcp->count) {
1124
			pcp->count = rmqueue_bulk(zone, 0,
1125 1126
					pcp->batch, &pcp->list,
					migratetype, cold);
N
Nick Piggin 已提交
1127 1128
			if (unlikely(!pcp->count))
				goto failed;
L
Linus Torvalds 已提交
1129
		}
1130

1131
		/* Find a page of the appropriate migrate type */
1132 1133 1134 1135 1136 1137 1138 1139 1140
		if (cold) {
			list_for_each_entry_reverse(page, &pcp->list, lru)
				if (page_private(page) == migratetype)
					break;
		} else {
			list_for_each_entry(page, &pcp->list, lru)
				if (page_private(page) == migratetype)
					break;
		}
1141

1142 1143
		/* Allocate more to the pcp list if necessary */
		if (unlikely(&page->lru == &pcp->list)) {
1144
			pcp->count += rmqueue_bulk(zone, 0,
1145 1146
					pcp->batch, &pcp->list,
					migratetype, cold);
1147 1148
			page = list_entry(pcp->list.next, struct page, lru);
		}
1149 1150 1151

		list_del(&page->lru);
		pcp->count--;
R
Rohit Seth 已提交
1152
	} else {
1153 1154 1155 1156 1157 1158 1159 1160
		if (unlikely(gfp_flags & __GFP_NOFAIL)) {
			/*
			 * __GFP_NOFAIL is not to be used in new code.
			 *
			 * All __GFP_NOFAIL callers should be fixed so that they
			 * properly detect and handle allocation failures.
			 *
			 * We most definitely don't want callers attempting to
1161
			 * allocate greater than order-1 page units with
1162 1163
			 * __GFP_NOFAIL.
			 */
1164
			WARN_ON_ONCE(order > 1);
1165
		}
L
Linus Torvalds 已提交
1166
		spin_lock_irqsave(&zone->lock, flags);
1167
		page = __rmqueue(zone, order, migratetype);
1168
		__mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
N
Nick Piggin 已提交
1169 1170 1171
		spin_unlock(&zone->lock);
		if (!page)
			goto failed;
L
Linus Torvalds 已提交
1172 1173
	}

1174
	__count_zone_vm_events(PGALLOC, zone, 1 << order);
1175
	zone_statistics(preferred_zone, zone);
N
Nick Piggin 已提交
1176 1177
	local_irq_restore(flags);
	put_cpu();
L
Linus Torvalds 已提交
1178

N
Nick Piggin 已提交
1179
	VM_BUG_ON(bad_range(zone, page));
N
Nick Piggin 已提交
1180
	if (prep_new_page(page, order, gfp_flags))
N
Nick Piggin 已提交
1181
		goto again;
L
Linus Torvalds 已提交
1182
	return page;
N
Nick Piggin 已提交
1183 1184 1185 1186 1187

failed:
	local_irq_restore(flags);
	put_cpu();
	return NULL;
L
Linus Torvalds 已提交
1188 1189
}

1190 1191 1192 1193 1194 1195 1196 1197 1198
/* The ALLOC_WMARK bits are used as an index to zone->watermark */
#define ALLOC_WMARK_MIN		WMARK_MIN
#define ALLOC_WMARK_LOW		WMARK_LOW
#define ALLOC_WMARK_HIGH	WMARK_HIGH
#define ALLOC_NO_WATERMARKS	0x04 /* don't check watermarks at all */

/* Mask to get the watermark bits */
#define ALLOC_WMARK_MASK	(ALLOC_NO_WATERMARKS-1)

1199 1200 1201
#define ALLOC_HARDER		0x10 /* try to alloc harder */
#define ALLOC_HIGH		0x20 /* __GFP_HIGH set */
#define ALLOC_CPUSET		0x40 /* check for correct cpuset */
R
Rohit Seth 已提交
1202

1203 1204 1205 1206 1207 1208 1209
#ifdef CONFIG_FAIL_PAGE_ALLOC

static struct fail_page_alloc_attr {
	struct fault_attr attr;

	u32 ignore_gfp_highmem;
	u32 ignore_gfp_wait;
1210
	u32 min_order;
1211 1212 1213 1214 1215

#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS

	struct dentry *ignore_gfp_highmem_file;
	struct dentry *ignore_gfp_wait_file;
1216
	struct dentry *min_order_file;
1217 1218 1219 1220 1221

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

} fail_page_alloc = {
	.attr = FAULT_ATTR_INITIALIZER,
1222 1223
	.ignore_gfp_wait = 1,
	.ignore_gfp_highmem = 1,
1224
	.min_order = 1,
1225 1226 1227 1228 1229 1230 1231 1232 1233 1234
};

static int __init setup_fail_page_alloc(char *str)
{
	return setup_fault_attr(&fail_page_alloc.attr, str);
}
__setup("fail_page_alloc=", setup_fail_page_alloc);

static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
{
1235 1236
	if (order < fail_page_alloc.min_order)
		return 0;
1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267
	if (gfp_mask & __GFP_NOFAIL)
		return 0;
	if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
		return 0;
	if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
		return 0;

	return should_fail(&fail_page_alloc.attr, 1 << order);
}

#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS

static int __init fail_page_alloc_debugfs(void)
{
	mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
	struct dentry *dir;
	int err;

	err = init_fault_attr_dentries(&fail_page_alloc.attr,
				       "fail_page_alloc");
	if (err)
		return err;
	dir = fail_page_alloc.attr.dentries.dir;

	fail_page_alloc.ignore_gfp_wait_file =
		debugfs_create_bool("ignore-gfp-wait", mode, dir,
				      &fail_page_alloc.ignore_gfp_wait);

	fail_page_alloc.ignore_gfp_highmem_file =
		debugfs_create_bool("ignore-gfp-highmem", mode, dir,
				      &fail_page_alloc.ignore_gfp_highmem);
1268 1269 1270
	fail_page_alloc.min_order_file =
		debugfs_create_u32("min-order", mode, dir,
				   &fail_page_alloc.min_order);
1271 1272

	if (!fail_page_alloc.ignore_gfp_wait_file ||
1273 1274
            !fail_page_alloc.ignore_gfp_highmem_file ||
            !fail_page_alloc.min_order_file) {
1275 1276 1277
		err = -ENOMEM;
		debugfs_remove(fail_page_alloc.ignore_gfp_wait_file);
		debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file);
1278
		debugfs_remove(fail_page_alloc.min_order_file);
1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297
		cleanup_fault_attr_dentries(&fail_page_alloc.attr);
	}

	return err;
}

late_initcall(fail_page_alloc_debugfs);

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

#else /* CONFIG_FAIL_PAGE_ALLOC */

static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
{
	return 0;
}

#endif /* CONFIG_FAIL_PAGE_ALLOC */

L
Linus Torvalds 已提交
1298 1299 1300 1301 1302
/*
 * Return 1 if free pages are above 'mark'. This takes into account the order
 * of the allocation.
 */
int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
R
Rohit Seth 已提交
1303
		      int classzone_idx, int alloc_flags)
L
Linus Torvalds 已提交
1304 1305
{
	/* free_pages my go negative - that's OK */
1306 1307
	long min = mark;
	long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1;
L
Linus Torvalds 已提交
1308 1309
	int o;

R
Rohit Seth 已提交
1310
	if (alloc_flags & ALLOC_HIGH)
L
Linus Torvalds 已提交
1311
		min -= min / 2;
R
Rohit Seth 已提交
1312
	if (alloc_flags & ALLOC_HARDER)
L
Linus Torvalds 已提交
1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329
		min -= min / 4;

	if (free_pages <= min + z->lowmem_reserve[classzone_idx])
		return 0;
	for (o = 0; o < order; o++) {
		/* At the next order, this order's pages become unavailable */
		free_pages -= z->free_area[o].nr_free << o;

		/* Require fewer higher order pages to be free */
		min >>= 1;

		if (free_pages <= min)
			return 0;
	}
	return 1;
}

1330 1331 1332 1333 1334 1335
#ifdef CONFIG_NUMA
/*
 * zlc_setup - Setup for "zonelist cache".  Uses cached zone data to
 * skip over zones that are not allowed by the cpuset, or that have
 * been recently (in last second) found to be nearly full.  See further
 * comments in mmzone.h.  Reduces cache footprint of zonelist scans
S
Simon Arlott 已提交
1336
 * that have to skip over a lot of full or unallowed zones.
1337 1338 1339
 *
 * If the zonelist cache is present in the passed in zonelist, then
 * returns a pointer to the allowed node mask (either the current
1340
 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361
 *
 * If the zonelist cache is not available for this zonelist, does
 * nothing and returns NULL.
 *
 * If the fullzones BITMAP in the zonelist cache is stale (more than
 * a second since last zap'd) then we zap it out (clear its bits.)
 *
 * We hold off even calling zlc_setup, until after we've checked the
 * first zone in the zonelist, on the theory that most allocations will
 * be satisfied from that first zone, so best to examine that zone as
 * quickly as we can.
 */
static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	nodemask_t *allowednodes;	/* zonelist_cache approximation */

	zlc = zonelist->zlcache_ptr;
	if (!zlc)
		return NULL;

S
S.Caglar Onur 已提交
1362
	if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1363 1364 1365 1366 1367 1368
		bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
		zlc->last_full_zap = jiffies;
	}

	allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
					&cpuset_current_mems_allowed :
1369
					&node_states[N_HIGH_MEMORY];
1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394
	return allowednodes;
}

/*
 * Given 'z' scanning a zonelist, run a couple of quick checks to see
 * if it is worth looking at further for free memory:
 *  1) Check that the zone isn't thought to be full (doesn't have its
 *     bit set in the zonelist_cache fullzones BITMAP).
 *  2) Check that the zones node (obtained from the zonelist_cache
 *     z_to_n[] mapping) is allowed in the passed in allowednodes mask.
 * Return true (non-zero) if zone is worth looking at further, or
 * else return false (zero) if it is not.
 *
 * This check -ignores- the distinction between various watermarks,
 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ...  If a zone is
 * found to be full for any variation of these watermarks, it will
 * be considered full for up to one second by all requests, unless
 * we are so low on memory on all allowed nodes that we are forced
 * into the second scan of the zonelist.
 *
 * In the second scan we ignore this zonelist cache and exactly
 * apply the watermarks to all zones, even it is slower to do so.
 * We are low on memory in the second scan, and should leave no stone
 * unturned looking for a free page.
 */
1395
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1396 1397 1398 1399 1400 1401 1402 1403 1404 1405
						nodemask_t *allowednodes)
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	int i;				/* index of *z in zonelist zones */
	int n;				/* node that zone *z is on */

	zlc = zonelist->zlcache_ptr;
	if (!zlc)
		return 1;

1406
	i = z - zonelist->_zonerefs;
1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417
	n = zlc->z_to_n[i];

	/* This zone is worth trying if it is allowed but not full */
	return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones);
}

/*
 * Given 'z' scanning a zonelist, set the corresponding bit in
 * zlc->fullzones, so that subsequent attempts to allocate a page
 * from that zone don't waste time re-examining it.
 */
1418
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1419 1420 1421 1422 1423 1424 1425 1426
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	int i;				/* index of *z in zonelist zones */

	zlc = zonelist->zlcache_ptr;
	if (!zlc)
		return;

1427
	i = z - zonelist->_zonerefs;
1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438

	set_bit(i, zlc->fullzones);
}

#else	/* CONFIG_NUMA */

static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
{
	return NULL;
}

1439
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1440 1441 1442 1443 1444
				nodemask_t *allowednodes)
{
	return 1;
}

1445
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1446 1447 1448 1449
{
}
#endif	/* CONFIG_NUMA */

R
Rohit Seth 已提交
1450
/*
1451
 * get_page_from_freelist goes through the zonelist trying to allocate
R
Rohit Seth 已提交
1452 1453 1454
 * a page.
 */
static struct page *
1455
get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1456
		struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1457
		struct zone *preferred_zone, int migratetype)
M
Martin Hicks 已提交
1458
{
1459
	struct zoneref *z;
R
Rohit Seth 已提交
1460
	struct page *page = NULL;
1461
	int classzone_idx;
1462
	struct zone *zone;
1463 1464 1465
	nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */
	int zlc_active = 0;		/* set if using zonelist_cache */
	int did_zlc_setup = 0;		/* just call zlc_setup() one time */
1466

1467
	classzone_idx = zone_idx(preferred_zone);
1468
zonelist_scan:
R
Rohit Seth 已提交
1469
	/*
1470
	 * Scan zonelist, looking for a zone with enough free.
R
Rohit Seth 已提交
1471 1472
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
	 */
1473 1474
	for_each_zone_zonelist_nodemask(zone, z, zonelist,
						high_zoneidx, nodemask) {
1475 1476 1477
		if (NUMA_BUILD && zlc_active &&
			!zlc_zone_worth_trying(zonelist, z, allowednodes))
				continue;
R
Rohit Seth 已提交
1478
		if ((alloc_flags & ALLOC_CPUSET) &&
1479
			!cpuset_zone_allowed_softwall(zone, gfp_mask))
1480
				goto try_next_zone;
R
Rohit Seth 已提交
1481

1482
		BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
R
Rohit Seth 已提交
1483
		if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1484
			unsigned long mark;
1485 1486
			int ret;

1487
			mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506
			if (zone_watermark_ok(zone, order, mark,
				    classzone_idx, alloc_flags))
				goto try_this_zone;

			if (zone_reclaim_mode == 0)
				goto this_zone_full;

			ret = zone_reclaim(zone, gfp_mask, order);
			switch (ret) {
			case ZONE_RECLAIM_NOSCAN:
				/* did not scan */
				goto try_next_zone;
			case ZONE_RECLAIM_FULL:
				/* scanned but unreclaimable */
				goto this_zone_full;
			default:
				/* did we reclaim enough */
				if (!zone_watermark_ok(zone, order, mark,
						classzone_idx, alloc_flags))
1507
					goto this_zone_full;
1508
			}
R
Rohit Seth 已提交
1509 1510
		}

1511
try_this_zone:
1512 1513
		page = buffered_rmqueue(preferred_zone, zone, order,
						gfp_mask, migratetype);
1514
		if (page)
R
Rohit Seth 已提交
1515
			break;
1516 1517 1518 1519
this_zone_full:
		if (NUMA_BUILD)
			zlc_mark_zone_full(zonelist, z);
try_next_zone:
1520
		if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) {
1521 1522 1523 1524
			/*
			 * we do zlc_setup after the first zone is tried but only
			 * if there are multiple nodes make it worthwhile
			 */
1525 1526 1527 1528
			allowednodes = zlc_setup(zonelist, alloc_flags);
			zlc_active = 1;
			did_zlc_setup = 1;
		}
1529
	}
1530 1531 1532 1533 1534 1535

	if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) {
		/* Disable zlc cache for second zonelist scan */
		zlc_active = 0;
		goto zonelist_scan;
	}
R
Rohit Seth 已提交
1536
	return page;
M
Martin Hicks 已提交
1537 1538
}

1539 1540 1541
static inline int
should_alloc_retry(gfp_t gfp_mask, unsigned int order,
				unsigned long pages_reclaimed)
L
Linus Torvalds 已提交
1542
{
1543 1544 1545
	/* Do not loop if specifically requested */
	if (gfp_mask & __GFP_NORETRY)
		return 0;
L
Linus Torvalds 已提交
1546

1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563
	/*
	 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
	 * means __GFP_NOFAIL, but that may not be true in other
	 * implementations.
	 */
	if (order <= PAGE_ALLOC_COSTLY_ORDER)
		return 1;

	/*
	 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
	 * specified, then we retry until we no longer reclaim any pages
	 * (above), or we've reclaimed an order of pages at least as
	 * large as the allocation's order. In both cases, if the
	 * allocation still fails, we stop retrying.
	 */
	if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order))
		return 1;
1564

1565 1566 1567 1568 1569 1570
	/*
	 * Don't let big-order allocations loop unless the caller
	 * explicitly requests that.
	 */
	if (gfp_mask & __GFP_NOFAIL)
		return 1;
L
Linus Torvalds 已提交
1571

1572 1573
	return 0;
}
1574

1575 1576 1577
static inline struct page *
__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1578 1579
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1580 1581 1582 1583 1584 1585
{
	struct page *page;

	/* Acquire the OOM killer lock for the zones in zonelist */
	if (!try_set_zone_oom(zonelist, gfp_mask)) {
		schedule_timeout_uninterruptible(1);
L
Linus Torvalds 已提交
1586 1587
		return NULL;
	}
1588

1589 1590 1591 1592 1593 1594 1595
	/*
	 * Go through the zonelist yet one more time, keep very high watermark
	 * here, this is only to catch a parallel oom killing, we must fail if
	 * we're still under heavy pressure.
	 */
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask,
		order, zonelist, high_zoneidx,
1596
		ALLOC_WMARK_HIGH|ALLOC_CPUSET,
1597
		preferred_zone, migratetype);
R
Rohit Seth 已提交
1598
	if (page)
1599 1600 1601
		goto out;

	/* The OOM killer will not help higher order allocs */
1602
	if (order > PAGE_ALLOC_COSTLY_ORDER && !(gfp_mask & __GFP_NOFAIL))
1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616
		goto out;

	/* Exhausted what can be done so it's blamo time */
	out_of_memory(zonelist, gfp_mask, order);

out:
	clear_zonelist_oom(zonelist, gfp_mask);
	return page;
}

/* The really slow allocator path where we enter direct reclaim */
static inline struct page *
__alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1617
	nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
1618
	int migratetype, unsigned long *did_some_progress)
1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649
{
	struct page *page = NULL;
	struct reclaim_state reclaim_state;
	struct task_struct *p = current;

	cond_resched();

	/* We now go into synchronous reclaim */
	cpuset_memory_pressure_bump();

	/*
	 * The task's cpuset might have expanded its set of allowable nodes
	 */
	p->flags |= PF_MEMALLOC;
	lockdep_set_current_reclaim_state(gfp_mask);
	reclaim_state.reclaimed_slab = 0;
	p->reclaim_state = &reclaim_state;

	*did_some_progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask);

	p->reclaim_state = NULL;
	lockdep_clear_current_reclaim_state();
	p->flags &= ~PF_MEMALLOC;

	cond_resched();

	if (order != 0)
		drain_all_pages();

	if (likely(*did_some_progress))
		page = get_page_from_freelist(gfp_mask, nodemask, order,
1650
					zonelist, high_zoneidx,
1651 1652
					alloc_flags, preferred_zone,
					migratetype);
1653 1654 1655
	return page;
}

L
Linus Torvalds 已提交
1656
/*
1657 1658
 * This is called in the allocator slow-path if the allocation request is of
 * sufficient urgency to ignore watermarks and take other desperate measures
L
Linus Torvalds 已提交
1659
 */
1660 1661 1662
static inline struct page *
__alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1663 1664
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1665 1666 1667 1668 1669
{
	struct page *page;

	do {
		page = get_page_from_freelist(gfp_mask, nodemask, order,
1670
			zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
1671
			preferred_zone, migratetype);
1672 1673

		if (!page && gfp_mask & __GFP_NOFAIL)
1674
			congestion_wait(BLK_RW_ASYNC, HZ/50);
1675 1676 1677 1678 1679 1680 1681 1682
	} while (!page && (gfp_mask & __GFP_NOFAIL));

	return page;
}

static inline
void wake_all_kswapd(unsigned int order, struct zonelist *zonelist,
						enum zone_type high_zoneidx)
L
Linus Torvalds 已提交
1683
{
1684 1685
	struct zoneref *z;
	struct zone *zone;
L
Linus Torvalds 已提交
1686

1687 1688 1689
	for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
		wakeup_kswapd(zone, order);
}
1690

1691 1692 1693 1694 1695 1696
static inline int
gfp_to_alloc_flags(gfp_t gfp_mask)
{
	struct task_struct *p = current;
	int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
	const gfp_t wait = gfp_mask & __GFP_WAIT;
L
Linus Torvalds 已提交
1697

1698 1699
	/* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
	BUILD_BUG_ON(__GFP_HIGH != ALLOC_HIGH);
1700

1701 1702 1703 1704 1705 1706
	/*
	 * The caller may dip into page reserves a bit more if the caller
	 * cannot run direct reclaim, or if the caller has realtime scheduling
	 * policy or is asking for __GFP_HIGH memory.  GFP_ATOMIC requests will
	 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
	 */
1707
	alloc_flags |= (gfp_mask & __GFP_HIGH);
L
Linus Torvalds 已提交
1708

1709 1710
	if (!wait) {
		alloc_flags |= ALLOC_HARDER;
1711
		/*
1712 1713
		 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
		 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1714
		 */
1715 1716 1717 1718 1719 1720 1721 1722 1723
		alloc_flags &= ~ALLOC_CPUSET;
	} else if (unlikely(rt_task(p)))
		alloc_flags |= ALLOC_HARDER;

	if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
		if (!in_interrupt() &&
		    ((p->flags & PF_MEMALLOC) ||
		     unlikely(test_thread_flag(TIF_MEMDIE))))
			alloc_flags |= ALLOC_NO_WATERMARKS;
L
Linus Torvalds 已提交
1724
	}
1725

1726 1727 1728
	return alloc_flags;
}

1729 1730 1731
static inline struct page *
__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1732 1733
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1734 1735 1736 1737 1738 1739 1740
{
	const gfp_t wait = gfp_mask & __GFP_WAIT;
	struct page *page = NULL;
	int alloc_flags;
	unsigned long pages_reclaimed = 0;
	unsigned long did_some_progress;
	struct task_struct *p = current;
L
Linus Torvalds 已提交
1741

1742 1743 1744 1745 1746 1747
	/*
	 * In the slowpath, we sanity check order to avoid ever trying to
	 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
	 * be using allocators in order of preference for an area that is
	 * too large.
	 */
1748 1749
	if (order >= MAX_ORDER) {
		WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
1750
		return NULL;
1751
	}
L
Linus Torvalds 已提交
1752

1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763
	/*
	 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
	 * __GFP_NOWARN set) should not cause reclaim since the subsystem
	 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
	 * using a larger set of nodes after it has established that the
	 * allowed per node queues are empty and that nodes are
	 * over allocated.
	 */
	if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE)
		goto nopage;

1764
	wake_all_kswapd(order, zonelist, high_zoneidx);
L
Linus Torvalds 已提交
1765

1766
	/*
R
Rohit Seth 已提交
1767 1768 1769
	 * OK, we're below the kswapd watermark and have kicked background
	 * reclaim. Now things get more complex, so set up alloc_flags according
	 * to how we want to proceed.
1770
	 */
1771
	alloc_flags = gfp_to_alloc_flags(gfp_mask);
L
Linus Torvalds 已提交
1772

1773
restart:
1774
	/* This is the last chance, in general, before the goto nopage. */
1775
	page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
1776 1777
			high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
			preferred_zone, migratetype);
R
Rohit Seth 已提交
1778 1779
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1780

1781
rebalance:
1782
	/* Allocate without watermarks if the context allows */
1783 1784 1785 1786 1787 1788
	if (alloc_flags & ALLOC_NO_WATERMARKS) {
		page = __alloc_pages_high_priority(gfp_mask, order,
				zonelist, high_zoneidx, nodemask,
				preferred_zone, migratetype);
		if (page)
			goto got_pg;
L
Linus Torvalds 已提交
1789 1790 1791 1792 1793 1794
	}

	/* Atomic allocations - we can't balance anything */
	if (!wait)
		goto nopage;

1795 1796 1797 1798
	/* Avoid recursion of direct reclaim */
	if (p->flags & PF_MEMALLOC)
		goto nopage;

1799 1800 1801 1802
	/* Avoid allocations with no watermarks from looping endlessly */
	if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
		goto nopage;

1803 1804 1805 1806
	/* Try direct reclaim and then allocating */
	page = __alloc_pages_direct_reclaim(gfp_mask, order,
					zonelist, high_zoneidx,
					nodemask,
1807
					alloc_flags, preferred_zone,
1808
					migratetype, &did_some_progress);
1809 1810
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1811

1812
	/*
1813 1814
	 * If we failed to make any progress reclaiming, then we are
	 * running out of options and have to consider going OOM
1815
	 */
1816 1817
	if (!did_some_progress) {
		if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
1818 1819
			if (oom_killer_disabled)
				goto nopage;
1820 1821
			page = __alloc_pages_may_oom(gfp_mask, order,
					zonelist, high_zoneidx,
1822 1823
					nodemask, preferred_zone,
					migratetype);
1824 1825
			if (page)
				goto got_pg;
L
Linus Torvalds 已提交
1826

1827
			/*
1828 1829 1830 1831
			 * The OOM killer does not trigger for high-order
			 * ~__GFP_NOFAIL allocations so if no progress is being
			 * made, there are no other options and retrying is
			 * unlikely to help.
1832
			 */
1833 1834
			if (order > PAGE_ALLOC_COSTLY_ORDER &&
						!(gfp_mask & __GFP_NOFAIL))
1835
				goto nopage;
1836

1837 1838
			goto restart;
		}
L
Linus Torvalds 已提交
1839 1840
	}

1841
	/* Check if we should retry the allocation */
1842
	pages_reclaimed += did_some_progress;
1843 1844
	if (should_alloc_retry(gfp_mask, order, pages_reclaimed)) {
		/* Wait for some write requests to complete then retry */
1845
		congestion_wait(BLK_RW_ASYNC, HZ/50);
L
Linus Torvalds 已提交
1846 1847 1848 1849 1850 1851 1852 1853 1854
		goto rebalance;
	}

nopage:
	if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) {
		printk(KERN_WARNING "%s: page allocation failure."
			" order:%d, mode:0x%x\n",
			p->comm, order, gfp_mask);
		dump_stack();
J
Janet Morgan 已提交
1855
		show_mem();
L
Linus Torvalds 已提交
1856
	}
1857
	return page;
L
Linus Torvalds 已提交
1858
got_pg:
1859 1860
	if (kmemcheck_enabled)
		kmemcheck_pagealloc_alloc(page, order, gfp_mask);
L
Linus Torvalds 已提交
1861
	return page;
1862

L
Linus Torvalds 已提交
1863
}
1864 1865 1866 1867 1868 1869 1870 1871 1872

/*
 * This is the 'heart' of the zoned buddy allocator.
 */
struct page *
__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
			struct zonelist *zonelist, nodemask_t *nodemask)
{
	enum zone_type high_zoneidx = gfp_zone(gfp_mask);
1873
	struct zone *preferred_zone;
1874
	struct page *page;
1875
	int migratetype = allocflags_to_migratetype(gfp_mask);
1876

1877 1878
	gfp_mask &= gfp_allowed_mask;

1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893
	lockdep_trace_alloc(gfp_mask);

	might_sleep_if(gfp_mask & __GFP_WAIT);

	if (should_fail_alloc_page(gfp_mask, order))
		return NULL;

	/*
	 * Check the zones suitable for the gfp_mask contain at least one
	 * valid zone. It's possible to have an empty zonelist as a result
	 * of GFP_THISNODE and a memoryless node
	 */
	if (unlikely(!zonelist->_zonerefs->zone))
		return NULL;

1894 1895 1896 1897 1898 1899
	/* The preferred zone is used for statistics later */
	first_zones_zonelist(zonelist, high_zoneidx, nodemask, &preferred_zone);
	if (!preferred_zone)
		return NULL;

	/* First allocation attempt */
1900
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
1901
			zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET,
1902
			preferred_zone, migratetype);
1903 1904
	if (unlikely(!page))
		page = __alloc_pages_slowpath(gfp_mask, order,
1905
				zonelist, high_zoneidx, nodemask,
1906
				preferred_zone, migratetype);
1907 1908

	return page;
L
Linus Torvalds 已提交
1909
}
1910
EXPORT_SYMBOL(__alloc_pages_nodemask);
L
Linus Torvalds 已提交
1911 1912 1913 1914

/*
 * Common helper functions.
 */
H
Harvey Harrison 已提交
1915
unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
L
Linus Torvalds 已提交
1916 1917 1918 1919 1920 1921 1922 1923 1924 1925
{
	struct page * page;
	page = alloc_pages(gfp_mask, order);
	if (!page)
		return 0;
	return (unsigned long) page_address(page);
}

EXPORT_SYMBOL(__get_free_pages);

H
Harvey Harrison 已提交
1926
unsigned long get_zeroed_page(gfp_t gfp_mask)
L
Linus Torvalds 已提交
1927 1928 1929 1930 1931 1932 1933
{
	struct page * page;

	/*
	 * get_zeroed_page() returns a 32-bit address, which cannot represent
	 * a highmem page
	 */
N
Nick Piggin 已提交
1934
	VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
L
Linus Torvalds 已提交
1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951

	page = alloc_pages(gfp_mask | __GFP_ZERO, 0);
	if (page)
		return (unsigned long) page_address(page);
	return 0;
}

EXPORT_SYMBOL(get_zeroed_page);

void __pagevec_free(struct pagevec *pvec)
{
	int i = pagevec_count(pvec);

	while (--i >= 0)
		free_hot_cold_page(pvec->pages[i], pvec->cold);
}

H
Harvey Harrison 已提交
1952
void __free_pages(struct page *page, unsigned int order)
L
Linus Torvalds 已提交
1953
{
N
Nick Piggin 已提交
1954
	if (put_page_testzero(page)) {
L
Linus Torvalds 已提交
1955 1956 1957 1958 1959 1960 1961 1962 1963
		if (order == 0)
			free_hot_page(page);
		else
			__free_pages_ok(page, order);
	}
}

EXPORT_SYMBOL(__free_pages);

H
Harvey Harrison 已提交
1964
void free_pages(unsigned long addr, unsigned int order)
L
Linus Torvalds 已提交
1965 1966
{
	if (addr != 0) {
N
Nick Piggin 已提交
1967
		VM_BUG_ON(!virt_addr_valid((void *)addr));
L
Linus Torvalds 已提交
1968 1969 1970 1971 1972 1973
		__free_pages(virt_to_page((void *)addr), order);
	}
}

EXPORT_SYMBOL(free_pages);

1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996
/**
 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
 * @size: the number of bytes to allocate
 * @gfp_mask: GFP flags for the allocation
 *
 * This function is similar to alloc_pages(), except that it allocates the
 * minimum number of pages to satisfy the request.  alloc_pages() can only
 * allocate memory in power-of-two pages.
 *
 * This function is also limited by MAX_ORDER.
 *
 * Memory allocated by this function must be released by free_pages_exact().
 */
void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
{
	unsigned int order = get_order(size);
	unsigned long addr;

	addr = __get_free_pages(gfp_mask, order);
	if (addr) {
		unsigned long alloc_end = addr + (PAGE_SIZE << order);
		unsigned long used = addr + PAGE_ALIGN(size);

K
Kevin Cernekee 已提交
1997
		split_page(virt_to_page((void *)addr), order);
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026
		while (used < alloc_end) {
			free_page(used);
			used += PAGE_SIZE;
		}
	}

	return (void *)addr;
}
EXPORT_SYMBOL(alloc_pages_exact);

/**
 * free_pages_exact - release memory allocated via alloc_pages_exact()
 * @virt: the value returned by alloc_pages_exact.
 * @size: size of allocation, same value as passed to alloc_pages_exact().
 *
 * Release the memory allocated by a previous call to alloc_pages_exact.
 */
void free_pages_exact(void *virt, size_t size)
{
	unsigned long addr = (unsigned long)virt;
	unsigned long end = addr + PAGE_ALIGN(size);

	while (addr < end) {
		free_page(addr);
		addr += PAGE_SIZE;
	}
}
EXPORT_SYMBOL(free_pages_exact);

L
Linus Torvalds 已提交
2027 2028
static unsigned int nr_free_zone_pages(int offset)
{
2029
	struct zoneref *z;
2030 2031
	struct zone *zone;

2032
	/* Just pick one node, since fallback list is circular */
L
Linus Torvalds 已提交
2033 2034
	unsigned int sum = 0;

2035
	struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
L
Linus Torvalds 已提交
2036

2037
	for_each_zone_zonelist(zone, z, zonelist, offset) {
2038
		unsigned long size = zone->present_pages;
2039
		unsigned long high = high_wmark_pages(zone);
2040 2041
		if (size > high)
			sum += size - high;
L
Linus Torvalds 已提交
2042 2043 2044 2045 2046 2047 2048 2049 2050 2051
	}

	return sum;
}

/*
 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
 */
unsigned int nr_free_buffer_pages(void)
{
A
Al Viro 已提交
2052
	return nr_free_zone_pages(gfp_zone(GFP_USER));
L
Linus Torvalds 已提交
2053
}
2054
EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
L
Linus Torvalds 已提交
2055 2056 2057 2058 2059 2060

/*
 * Amount of free RAM allocatable within all zones
 */
unsigned int nr_free_pagecache_pages(void)
{
M
Mel Gorman 已提交
2061
	return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
L
Linus Torvalds 已提交
2062
}
2063 2064

static inline void show_node(struct zone *zone)
L
Linus Torvalds 已提交
2065
{
2066
	if (NUMA_BUILD)
2067
		printk("Node %d ", zone_to_nid(zone));
L
Linus Torvalds 已提交
2068 2069 2070 2071 2072 2073
}

void si_meminfo(struct sysinfo *val)
{
	val->totalram = totalram_pages;
	val->sharedram = 0;
2074
	val->freeram = global_page_state(NR_FREE_PAGES);
L
Linus Torvalds 已提交
2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088
	val->bufferram = nr_blockdev_pages();
	val->totalhigh = totalhigh_pages;
	val->freehigh = nr_free_highpages();
	val->mem_unit = PAGE_SIZE;
}

EXPORT_SYMBOL(si_meminfo);

#ifdef CONFIG_NUMA
void si_meminfo_node(struct sysinfo *val, int nid)
{
	pg_data_t *pgdat = NODE_DATA(nid);

	val->totalram = pgdat->node_present_pages;
2089
	val->freeram = node_page_state(nid, NR_FREE_PAGES);
2090
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
2091
	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
2092 2093
	val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
			NR_FREE_PAGES);
2094 2095 2096 2097
#else
	val->totalhigh = 0;
	val->freehigh = 0;
#endif
L
Linus Torvalds 已提交
2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110
	val->mem_unit = PAGE_SIZE;
}
#endif

#define K(x) ((x) << (PAGE_SHIFT-10))

/*
 * Show free area list (used inside shift_scroll-lock stuff)
 * We also calculate the percentage fragmentation. We do this by counting the
 * memory on each free list with the exception of the first item on the list.
 */
void show_free_areas(void)
{
2111
	int cpu;
L
Linus Torvalds 已提交
2112 2113
	struct zone *zone;

2114
	for_each_populated_zone(zone) {
2115 2116
		show_node(zone);
		printk("%s per-cpu:\n", zone->name);
L
Linus Torvalds 已提交
2117

2118
		for_each_online_cpu(cpu) {
L
Linus Torvalds 已提交
2119 2120
			struct per_cpu_pageset *pageset;

2121
			pageset = zone_pcp(zone, cpu);
L
Linus Torvalds 已提交
2122

2123 2124 2125
			printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
			       cpu, pageset->pcp.high,
			       pageset->pcp.batch, pageset->pcp.count);
L
Linus Torvalds 已提交
2126 2127 2128
		}
	}

L
Lee Schermerhorn 已提交
2129 2130 2131 2132
	printk("Active_anon:%lu active_file:%lu inactive_anon:%lu\n"
		" inactive_file:%lu"
		" unevictable:%lu"
		" dirty:%lu writeback:%lu unstable:%lu\n"
2133
		" free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n",
2134 2135 2136 2137
		global_page_state(NR_ACTIVE_ANON),
		global_page_state(NR_ACTIVE_FILE),
		global_page_state(NR_INACTIVE_ANON),
		global_page_state(NR_INACTIVE_FILE),
L
Lee Schermerhorn 已提交
2138
		global_page_state(NR_UNEVICTABLE),
2139
		global_page_state(NR_FILE_DIRTY),
2140
		global_page_state(NR_WRITEBACK),
2141
		global_page_state(NR_UNSTABLE_NFS),
2142
		global_page_state(NR_FREE_PAGES),
2143 2144
		global_page_state(NR_SLAB_RECLAIMABLE) +
			global_page_state(NR_SLAB_UNRECLAIMABLE),
2145
		global_page_state(NR_FILE_MAPPED),
2146 2147
		global_page_state(NR_PAGETABLE),
		global_page_state(NR_BOUNCE));
L
Linus Torvalds 已提交
2148

2149
	for_each_populated_zone(zone) {
L
Linus Torvalds 已提交
2150 2151 2152 2153 2154 2155 2156 2157
		int i;

		show_node(zone);
		printk("%s"
			" free:%lukB"
			" min:%lukB"
			" low:%lukB"
			" high:%lukB"
2158 2159 2160 2161
			" active_anon:%lukB"
			" inactive_anon:%lukB"
			" active_file:%lukB"
			" inactive_file:%lukB"
L
Lee Schermerhorn 已提交
2162
			" unevictable:%lukB"
L
Linus Torvalds 已提交
2163 2164 2165 2166 2167
			" present:%lukB"
			" pages_scanned:%lu"
			" all_unreclaimable? %s"
			"\n",
			zone->name,
2168
			K(zone_page_state(zone, NR_FREE_PAGES)),
2169 2170 2171
			K(min_wmark_pages(zone)),
			K(low_wmark_pages(zone)),
			K(high_wmark_pages(zone)),
2172 2173 2174 2175
			K(zone_page_state(zone, NR_ACTIVE_ANON)),
			K(zone_page_state(zone, NR_INACTIVE_ANON)),
			K(zone_page_state(zone, NR_ACTIVE_FILE)),
			K(zone_page_state(zone, NR_INACTIVE_FILE)),
L
Lee Schermerhorn 已提交
2176
			K(zone_page_state(zone, NR_UNEVICTABLE)),
L
Linus Torvalds 已提交
2177 2178
			K(zone->present_pages),
			zone->pages_scanned,
2179
			(zone_is_all_unreclaimable(zone) ? "yes" : "no")
L
Linus Torvalds 已提交
2180 2181 2182 2183 2184 2185 2186
			);
		printk("lowmem_reserve[]:");
		for (i = 0; i < MAX_NR_ZONES; i++)
			printk(" %lu", zone->lowmem_reserve[i]);
		printk("\n");
	}

2187
	for_each_populated_zone(zone) {
2188
 		unsigned long nr[MAX_ORDER], flags, order, total = 0;
L
Linus Torvalds 已提交
2189 2190 2191 2192 2193 2194

		show_node(zone);
		printk("%s: ", zone->name);

		spin_lock_irqsave(&zone->lock, flags);
		for (order = 0; order < MAX_ORDER; order++) {
2195 2196
			nr[order] = zone->free_area[order].nr_free;
			total += nr[order] << order;
L
Linus Torvalds 已提交
2197 2198
		}
		spin_unlock_irqrestore(&zone->lock, flags);
2199 2200
		for (order = 0; order < MAX_ORDER; order++)
			printk("%lu*%lukB ", nr[order], K(1UL) << order);
L
Linus Torvalds 已提交
2201 2202 2203
		printk("= %lukB\n", K(total));
	}

2204 2205
	printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));

L
Linus Torvalds 已提交
2206 2207 2208
	show_swap_cache_info();
}

2209 2210 2211 2212 2213 2214
static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
{
	zoneref->zone = zone;
	zoneref->zone_idx = zone_idx(zone);
}

L
Linus Torvalds 已提交
2215 2216
/*
 * Builds allocation fallback zone lists.
2217 2218
 *
 * Add all populated zones of a node to the zonelist.
L
Linus Torvalds 已提交
2219
 */
2220 2221
static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
				int nr_zones, enum zone_type zone_type)
L
Linus Torvalds 已提交
2222
{
2223 2224
	struct zone *zone;

2225
	BUG_ON(zone_type >= MAX_NR_ZONES);
2226
	zone_type++;
2227 2228

	do {
2229
		zone_type--;
2230
		zone = pgdat->node_zones + zone_type;
2231
		if (populated_zone(zone)) {
2232 2233
			zoneref_set_zone(zone,
				&zonelist->_zonerefs[nr_zones++]);
2234
			check_highest_zone(zone_type);
L
Linus Torvalds 已提交
2235
		}
2236

2237
	} while (zone_type);
2238
	return nr_zones;
L
Linus Torvalds 已提交
2239 2240
}

2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261

/*
 *  zonelist_order:
 *  0 = automatic detection of better ordering.
 *  1 = order by ([node] distance, -zonetype)
 *  2 = order by (-zonetype, [node] distance)
 *
 *  If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
 *  the same zonelist. So only NUMA can configure this param.
 */
#define ZONELIST_ORDER_DEFAULT  0
#define ZONELIST_ORDER_NODE     1
#define ZONELIST_ORDER_ZONE     2

/* zonelist order in the kernel.
 * set_zonelist_order() will set this to NODE or ZONE.
 */
static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};


L
Linus Torvalds 已提交
2262
#ifdef CONFIG_NUMA
2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333
/* The value user specified ....changed by config */
static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
/* string for sysctl */
#define NUMA_ZONELIST_ORDER_LEN	16
char numa_zonelist_order[16] = "default";

/*
 * interface for configure zonelist ordering.
 * command line option "numa_zonelist_order"
 *	= "[dD]efault	- default, automatic configuration.
 *	= "[nN]ode 	- order by node locality, then by zone within node
 *	= "[zZ]one      - order by zone, then by locality within zone
 */

static int __parse_numa_zonelist_order(char *s)
{
	if (*s == 'd' || *s == 'D') {
		user_zonelist_order = ZONELIST_ORDER_DEFAULT;
	} else if (*s == 'n' || *s == 'N') {
		user_zonelist_order = ZONELIST_ORDER_NODE;
	} else if (*s == 'z' || *s == 'Z') {
		user_zonelist_order = ZONELIST_ORDER_ZONE;
	} else {
		printk(KERN_WARNING
			"Ignoring invalid numa_zonelist_order value:  "
			"%s\n", s);
		return -EINVAL;
	}
	return 0;
}

static __init int setup_numa_zonelist_order(char *s)
{
	if (s)
		return __parse_numa_zonelist_order(s);
	return 0;
}
early_param("numa_zonelist_order", setup_numa_zonelist_order);

/*
 * sysctl handler for numa_zonelist_order
 */
int numa_zonelist_order_handler(ctl_table *table, int write,
		struct file *file, void __user *buffer, size_t *length,
		loff_t *ppos)
{
	char saved_string[NUMA_ZONELIST_ORDER_LEN];
	int ret;

	if (write)
		strncpy(saved_string, (char*)table->data,
			NUMA_ZONELIST_ORDER_LEN);
	ret = proc_dostring(table, write, file, buffer, length, ppos);
	if (ret)
		return ret;
	if (write) {
		int oldval = user_zonelist_order;
		if (__parse_numa_zonelist_order((char*)table->data)) {
			/*
			 * bogus value.  restore saved string
			 */
			strncpy((char*)table->data, saved_string,
				NUMA_ZONELIST_ORDER_LEN);
			user_zonelist_order = oldval;
		} else if (oldval != user_zonelist_order)
			build_all_zonelists();
	}
	return 0;
}


2334
#define MAX_NODE_LOAD (nr_online_nodes)
2335 2336
static int node_load[MAX_NUMNODES];

L
Linus Torvalds 已提交
2337
/**
2338
 * find_next_best_node - find the next node that should appear in a given node's fallback list
L
Linus Torvalds 已提交
2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350
 * @node: node whose fallback list we're appending
 * @used_node_mask: nodemask_t of already used nodes
 *
 * We use a number of factors to determine which is the next node that should
 * appear on a given node's fallback list.  The node should not have appeared
 * already in @node's fallback list, and it should be the next closest node
 * according to the distance array (which contains arbitrary distance values
 * from each node to each node in the system), and should also prefer nodes
 * with no CPUs, since presumably they'll have very little allocation pressure
 * on them otherwise.
 * It returns -1 if no node is found.
 */
2351
static int find_next_best_node(int node, nodemask_t *used_node_mask)
L
Linus Torvalds 已提交
2352
{
2353
	int n, val;
L
Linus Torvalds 已提交
2354 2355
	int min_val = INT_MAX;
	int best_node = -1;
2356
	const struct cpumask *tmp = cpumask_of_node(0);
L
Linus Torvalds 已提交
2357

2358 2359 2360 2361 2362
	/* Use the local node if we haven't already */
	if (!node_isset(node, *used_node_mask)) {
		node_set(node, *used_node_mask);
		return node;
	}
L
Linus Torvalds 已提交
2363

2364
	for_each_node_state(n, N_HIGH_MEMORY) {
L
Linus Torvalds 已提交
2365 2366 2367 2368 2369 2370 2371 2372

		/* Don't want a node to appear more than once */
		if (node_isset(n, *used_node_mask))
			continue;

		/* Use the distance array to find the distance */
		val = node_distance(node, n);

2373 2374 2375
		/* Penalize nodes under us ("prefer the next node") */
		val += (n < node);

L
Linus Torvalds 已提交
2376
		/* Give preference to headless and unused nodes */
2377 2378
		tmp = cpumask_of_node(n);
		if (!cpumask_empty(tmp))
L
Linus Torvalds 已提交
2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396
			val += PENALTY_FOR_NODE_WITH_CPUS;

		/* Slight preference for less loaded node */
		val *= (MAX_NODE_LOAD*MAX_NUMNODES);
		val += node_load[n];

		if (val < min_val) {
			min_val = val;
			best_node = n;
		}
	}

	if (best_node >= 0)
		node_set(best_node, *used_node_mask);

	return best_node;
}

2397 2398 2399 2400 2401 2402 2403

/*
 * Build zonelists ordered by node and zones within node.
 * This results in maximum locality--normal zone overflows into local
 * DMA zone, if any--but risks exhausting DMA zone.
 */
static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
L
Linus Torvalds 已提交
2404
{
2405
	int j;
L
Linus Torvalds 已提交
2406
	struct zonelist *zonelist;
2407

2408
	zonelist = &pgdat->node_zonelists[0];
2409
	for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
2410 2411 2412
		;
	j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
2413 2414
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2415 2416
}

2417 2418 2419 2420 2421 2422 2423 2424
/*
 * Build gfp_thisnode zonelists
 */
static void build_thisnode_zonelists(pg_data_t *pgdat)
{
	int j;
	struct zonelist *zonelist;

2425 2426
	zonelist = &pgdat->node_zonelists[1];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2427 2428
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2429 2430
}

2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445
/*
 * Build zonelists ordered by zone and nodes within zones.
 * This results in conserving DMA zone[s] until all Normal memory is
 * exhausted, but results in overflowing to remote node while memory
 * may still exist in local DMA zone.
 */
static int node_order[MAX_NUMNODES];

static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
{
	int pos, j, node;
	int zone_type;		/* needs to be signed */
	struct zone *z;
	struct zonelist *zonelist;

2446 2447 2448 2449 2450 2451 2452
	zonelist = &pgdat->node_zonelists[0];
	pos = 0;
	for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
		for (j = 0; j < nr_nodes; j++) {
			node = node_order[j];
			z = &NODE_DATA(node)->node_zones[zone_type];
			if (populated_zone(z)) {
2453 2454
				zoneref_set_zone(z,
					&zonelist->_zonerefs[pos++]);
2455
				check_highest_zone(zone_type);
2456 2457 2458
			}
		}
	}
2459 2460
	zonelist->_zonerefs[pos].zone = NULL;
	zonelist->_zonerefs[pos].zone_idx = 0;
2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495
}

static int default_zonelist_order(void)
{
	int nid, zone_type;
	unsigned long low_kmem_size,total_size;
	struct zone *z;
	int average_size;
	/*
         * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem.
	 * If they are really small and used heavily, the system can fall
	 * into OOM very easily.
	 * This function detect ZONE_DMA/DMA32 size and confgigures zone order.
	 */
	/* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
	low_kmem_size = 0;
	total_size = 0;
	for_each_online_node(nid) {
		for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
			z = &NODE_DATA(nid)->node_zones[zone_type];
			if (populated_zone(z)) {
				if (zone_type < ZONE_NORMAL)
					low_kmem_size += z->present_pages;
				total_size += z->present_pages;
			}
		}
	}
	if (!low_kmem_size ||  /* there are no DMA area. */
	    low_kmem_size > total_size/2) /* DMA/DMA32 is big. */
		return ZONELIST_ORDER_NODE;
	/*
	 * look into each node's config.
  	 * If there is a node whose DMA/DMA32 memory is very big area on
 	 * local memory, NODE_ORDER may be suitable.
         */
2496 2497
	average_size = total_size /
				(nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528
	for_each_online_node(nid) {
		low_kmem_size = 0;
		total_size = 0;
		for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
			z = &NODE_DATA(nid)->node_zones[zone_type];
			if (populated_zone(z)) {
				if (zone_type < ZONE_NORMAL)
					low_kmem_size += z->present_pages;
				total_size += z->present_pages;
			}
		}
		if (low_kmem_size &&
		    total_size > average_size && /* ignore small node */
		    low_kmem_size > total_size * 70/100)
			return ZONELIST_ORDER_NODE;
	}
	return ZONELIST_ORDER_ZONE;
}

static void set_zonelist_order(void)
{
	if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
		current_zonelist_order = default_zonelist_order();
	else
		current_zonelist_order = user_zonelist_order;
}

static void build_zonelists(pg_data_t *pgdat)
{
	int j, node, load;
	enum zone_type i;
L
Linus Torvalds 已提交
2529
	nodemask_t used_mask;
2530 2531 2532
	int local_node, prev_node;
	struct zonelist *zonelist;
	int order = current_zonelist_order;
L
Linus Torvalds 已提交
2533 2534

	/* initialize zonelists */
2535
	for (i = 0; i < MAX_ZONELISTS; i++) {
L
Linus Torvalds 已提交
2536
		zonelist = pgdat->node_zonelists + i;
2537 2538
		zonelist->_zonerefs[0].zone = NULL;
		zonelist->_zonerefs[0].zone_idx = 0;
L
Linus Torvalds 已提交
2539 2540 2541 2542
	}

	/* NUMA-aware ordering of nodes */
	local_node = pgdat->node_id;
2543
	load = nr_online_nodes;
L
Linus Torvalds 已提交
2544 2545
	prev_node = local_node;
	nodes_clear(used_mask);
2546 2547 2548 2549

	memset(node_order, 0, sizeof(node_order));
	j = 0;

L
Linus Torvalds 已提交
2550
	while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
2551 2552 2553 2554 2555 2556 2557 2558 2559
		int distance = node_distance(local_node, node);

		/*
		 * If another node is sufficiently far away then it is better
		 * to reclaim pages in a zone before going off node.
		 */
		if (distance > RECLAIM_DISTANCE)
			zone_reclaim_mode = 1;

L
Linus Torvalds 已提交
2560 2561 2562 2563 2564
		/*
		 * We don't want to pressure a particular node.
		 * So adding penalty to the first node in same
		 * distance group to make it round-robin.
		 */
2565
		if (distance != node_distance(local_node, prev_node))
2566 2567
			node_load[node] = load;

L
Linus Torvalds 已提交
2568 2569
		prev_node = node;
		load--;
2570 2571 2572 2573 2574
		if (order == ZONELIST_ORDER_NODE)
			build_zonelists_in_node_order(pgdat, node);
		else
			node_order[j++] = node;	/* remember order */
	}
L
Linus Torvalds 已提交
2575

2576 2577 2578
	if (order == ZONELIST_ORDER_ZONE) {
		/* calculate node order -- i.e., DMA last! */
		build_zonelists_in_zone_order(pgdat, j);
L
Linus Torvalds 已提交
2579
	}
2580 2581

	build_thisnode_zonelists(pgdat);
L
Linus Torvalds 已提交
2582 2583
}

2584
/* Construct the zonelist performance cache - see further mmzone.h */
2585
static void build_zonelist_cache(pg_data_t *pgdat)
2586
{
2587 2588
	struct zonelist *zonelist;
	struct zonelist_cache *zlc;
2589
	struct zoneref *z;
2590

2591 2592 2593
	zonelist = &pgdat->node_zonelists[0];
	zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
	bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
2594 2595
	for (z = zonelist->_zonerefs; z->zone; z++)
		zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
2596 2597
}

2598

L
Linus Torvalds 已提交
2599 2600
#else	/* CONFIG_NUMA */

2601 2602 2603 2604 2605 2606
static void set_zonelist_order(void)
{
	current_zonelist_order = ZONELIST_ORDER_ZONE;
}

static void build_zonelists(pg_data_t *pgdat)
L
Linus Torvalds 已提交
2607
{
2608
	int node, local_node;
2609 2610
	enum zone_type j;
	struct zonelist *zonelist;
L
Linus Torvalds 已提交
2611 2612 2613

	local_node = pgdat->node_id;

2614 2615
	zonelist = &pgdat->node_zonelists[0];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
L
Linus Torvalds 已提交
2616

2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629
	/*
	 * Now we build the zonelist so that it contains the zones
	 * of all the other nodes.
	 * We don't want to pressure a particular node, so when
	 * building the zones for node N, we make sure that the
	 * zones coming right after the local ones are those from
	 * node N+1 (modulo N)
	 */
	for (node = local_node + 1; node < MAX_NUMNODES; node++) {
		if (!node_online(node))
			continue;
		j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
L
Linus Torvalds 已提交
2630
	}
2631 2632 2633 2634 2635 2636 2637
	for (node = 0; node < local_node; node++) {
		if (!node_online(node))
			continue;
		j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
	}

2638 2639
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
L
Linus Torvalds 已提交
2640 2641
}

2642
/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2643
static void build_zonelist_cache(pg_data_t *pgdat)
2644
{
2645
	pgdat->node_zonelists[0].zlcache_ptr = NULL;
2646 2647
}

L
Linus Torvalds 已提交
2648 2649
#endif	/* CONFIG_NUMA */

2650
/* return values int ....just for stop_machine() */
2651
static int __build_all_zonelists(void *dummy)
L
Linus Torvalds 已提交
2652
{
2653
	int nid;
2654

2655 2656 2657
#ifdef CONFIG_NUMA
	memset(node_load, 0, sizeof(node_load));
#endif
2658
	for_each_online_node(nid) {
2659 2660 2661 2662
		pg_data_t *pgdat = NODE_DATA(nid);

		build_zonelists(pgdat);
		build_zonelist_cache(pgdat);
2663
	}
2664 2665 2666
	return 0;
}

2667
void build_all_zonelists(void)
2668
{
2669 2670
	set_zonelist_order();

2671
	if (system_state == SYSTEM_BOOTING) {
2672
		__build_all_zonelists(NULL);
2673
		mminit_verify_zonelist();
2674 2675
		cpuset_init_current_mems_allowed();
	} else {
S
Simon Arlott 已提交
2676
		/* we have to stop all cpus to guarantee there is no user
2677
		   of zonelist */
2678
		stop_machine(__build_all_zonelists, NULL, NULL);
2679 2680
		/* cpuset refresh routine should be here */
	}
2681
	vm_total_pages = nr_free_pagecache_pages();
2682 2683 2684 2685 2686 2687 2688
	/*
	 * Disable grouping by mobility if the number of pages in the
	 * system is too low to allow the mechanism to work. It would be
	 * more accurate, but expensive to check per-zone. This check is
	 * made on memory-hotadd so a system can start with mobility
	 * disabled and enable it later
	 */
2689
	if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
2690 2691 2692 2693 2694 2695
		page_group_by_mobility_disabled = 1;
	else
		page_group_by_mobility_disabled = 0;

	printk("Built %i zonelists in %s order, mobility grouping %s.  "
		"Total pages: %ld\n",
2696
			nr_online_nodes,
2697
			zonelist_order_name[current_zonelist_order],
2698
			page_group_by_mobility_disabled ? "off" : "on",
2699 2700 2701 2702
			vm_total_pages);
#ifdef CONFIG_NUMA
	printk("Policy zone: %s\n", zone_names[policy_zone]);
#endif
L
Linus Torvalds 已提交
2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717
}

/*
 * Helper functions to size the waitqueue hash table.
 * Essentially these want to choose hash table sizes sufficiently
 * large so that collisions trying to wait on pages are rare.
 * But in fact, the number of active page waitqueues on typical
 * systems is ridiculously low, less than 200. So this is even
 * conservative, even though it seems large.
 *
 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
 * waitqueues, i.e. the size of the waitq table given the number of pages.
 */
#define PAGES_PER_WAITQUEUE	256

2718
#ifndef CONFIG_MEMORY_HOTPLUG
2719
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
L
Linus Torvalds 已提交
2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736
{
	unsigned long size = 1;

	pages /= PAGES_PER_WAITQUEUE;

	while (size < pages)
		size <<= 1;

	/*
	 * Once we have dozens or even hundreds of threads sleeping
	 * on IO we've got bigger problems than wait queue collision.
	 * Limit the size of the wait table to a reasonable size.
	 */
	size = min(size, 4096UL);

	return max(size, 4UL);
}
2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759
#else
/*
 * A zone's size might be changed by hot-add, so it is not possible to determine
 * a suitable size for its wait_table.  So we use the maximum size now.
 *
 * The max wait table size = 4096 x sizeof(wait_queue_head_t).   ie:
 *
 *    i386 (preemption config)    : 4096 x 16 = 64Kbyte.
 *    ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
 *    ia64, x86-64 (preemption)   : 4096 x 24 = 96Kbyte.
 *
 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
 * or more by the traditional way. (See above).  It equals:
 *
 *    i386, x86-64, powerpc(4K page size) : =  ( 2G + 1M)byte.
 *    ia64(16K page size)                 : =  ( 8G + 4M)byte.
 *    powerpc (64K page size)             : =  (32G +16M)byte.
 */
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
{
	return 4096UL;
}
#endif
L
Linus Torvalds 已提交
2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772

/*
 * This is an integer logarithm so that shifts can be used later
 * to extract the more random high bits from the multiplicative
 * hash function before the remainder is taken.
 */
static inline unsigned long wait_table_bits(unsigned long size)
{
	return ffz(~size);
}

#define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))

2773
/*
2774
 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2775 2776
 * of blocks reserved is based on min_wmark_pages(zone). The memory within
 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788
 * higher will lead to a bigger reserve which will get freed as contiguous
 * blocks as reclaim kicks in
 */
static void setup_zone_migrate_reserve(struct zone *zone)
{
	unsigned long start_pfn, pfn, end_pfn;
	struct page *page;
	unsigned long reserve, block_migratetype;

	/* Get the start pfn, end pfn and the number of blocks to reserve */
	start_pfn = zone->zone_start_pfn;
	end_pfn = start_pfn + zone->spanned_pages;
2789
	reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
2790
							pageblock_order;
2791

2792
	for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
2793 2794 2795 2796
		if (!pfn_valid(pfn))
			continue;
		page = pfn_to_page(pfn);

2797 2798 2799 2800
		/* Watch out for overlapping nodes */
		if (page_to_nid(page) != zone_to_nid(zone))
			continue;

2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830
		/* Blocks with reserved pages will never free, skip them. */
		if (PageReserved(page))
			continue;

		block_migratetype = get_pageblock_migratetype(page);

		/* If this block is reserved, account for it */
		if (reserve > 0 && block_migratetype == MIGRATE_RESERVE) {
			reserve--;
			continue;
		}

		/* Suitable for reserving if this block is movable */
		if (reserve > 0 && block_migratetype == MIGRATE_MOVABLE) {
			set_pageblock_migratetype(page, MIGRATE_RESERVE);
			move_freepages_block(zone, page, MIGRATE_RESERVE);
			reserve--;
			continue;
		}

		/*
		 * If the reserve is met and this is a previous reserved block,
		 * take it back
		 */
		if (block_migratetype == MIGRATE_RESERVE) {
			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
			move_freepages_block(zone, page, MIGRATE_MOVABLE);
		}
	}
}
M
Mel Gorman 已提交
2831

L
Linus Torvalds 已提交
2832 2833 2834 2835 2836
/*
 * Initially all pages are reserved - free ones are freed
 * up by free_all_bootmem() once the early boot process is
 * done. Non-atomic initialization, single-pass.
 */
2837
void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
D
Dave Hansen 已提交
2838
		unsigned long start_pfn, enum memmap_context context)
L
Linus Torvalds 已提交
2839 2840
{
	struct page *page;
A
Andy Whitcroft 已提交
2841 2842
	unsigned long end_pfn = start_pfn + size;
	unsigned long pfn;
2843
	struct zone *z;
L
Linus Torvalds 已提交
2844

2845 2846 2847
	if (highest_memmap_pfn < end_pfn - 1)
		highest_memmap_pfn = end_pfn - 1;

2848
	z = &NODE_DATA(nid)->node_zones[zone];
2849
	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
D
Dave Hansen 已提交
2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860
		/*
		 * There can be holes in boot-time mem_map[]s
		 * handed to this function.  They do not
		 * exist on hotplugged memory.
		 */
		if (context == MEMMAP_EARLY) {
			if (!early_pfn_valid(pfn))
				continue;
			if (!early_pfn_in_nid(pfn, nid))
				continue;
		}
A
Andy Whitcroft 已提交
2861 2862
		page = pfn_to_page(pfn);
		set_page_links(page, zone, nid, pfn);
2863
		mminit_verify_page_links(page, zone, nid, pfn);
2864
		init_page_count(page);
L
Linus Torvalds 已提交
2865 2866
		reset_page_mapcount(page);
		SetPageReserved(page);
2867 2868 2869 2870 2871
		/*
		 * Mark the block movable so that blocks are reserved for
		 * movable at startup. This will force kernel allocations
		 * to reserve their blocks rather than leaking throughout
		 * the address space during boot when many long-lived
2872 2873 2874
		 * kernel allocations are made. Later some blocks near
		 * the start are marked MIGRATE_RESERVE by
		 * setup_zone_migrate_reserve()
2875 2876 2877 2878 2879
		 *
		 * bitmap is created for zone's valid pfn range. but memmap
		 * can be created for invalid pages (for alignment)
		 * check here not to call set_pageblock_migratetype() against
		 * pfn out of zone.
2880
		 */
2881 2882 2883
		if ((z->zone_start_pfn <= pfn)
		    && (pfn < z->zone_start_pfn + z->spanned_pages)
		    && !(pfn & (pageblock_nr_pages - 1)))
2884
			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
2885

L
Linus Torvalds 已提交
2886 2887 2888 2889
		INIT_LIST_HEAD(&page->lru);
#ifdef WANT_PAGE_VIRTUAL
		/* The shift won't overflow because ZONE_NORMAL is below 4G. */
		if (!is_highmem_idx(zone))
2890
			set_page_address(page, __va(pfn << PAGE_SHIFT));
L
Linus Torvalds 已提交
2891 2892 2893 2894
#endif
	}
}

2895
static void __meminit zone_init_free_lists(struct zone *zone)
L
Linus Torvalds 已提交
2896
{
2897 2898 2899
	int order, t;
	for_each_migratetype_order(order, t) {
		INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
L
Linus Torvalds 已提交
2900 2901 2902 2903 2904 2905
		zone->free_area[order].nr_free = 0;
	}
}

#ifndef __HAVE_ARCH_MEMMAP_INIT
#define memmap_init(size, nid, zone, start_pfn) \
D
Dave Hansen 已提交
2906
	memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
L
Linus Torvalds 已提交
2907 2908
#endif

2909
static int zone_batchsize(struct zone *zone)
2910
{
2911
#ifdef CONFIG_MMU
2912 2913 2914 2915
	int batch;

	/*
	 * The per-cpu-pages pools are set to around 1000th of the
2916
	 * size of the zone.  But no more than 1/2 of a meg.
2917 2918 2919 2920
	 *
	 * OK, so we don't know how big the cache is.  So guess.
	 */
	batch = zone->present_pages / 1024;
2921 2922
	if (batch * PAGE_SIZE > 512 * 1024)
		batch = (512 * 1024) / PAGE_SIZE;
2923 2924 2925 2926 2927
	batch /= 4;		/* We effectively *= 4 below */
	if (batch < 1)
		batch = 1;

	/*
2928 2929 2930
	 * Clamp the batch to a 2^n - 1 value. Having a power
	 * of 2 value was found to be more likely to have
	 * suboptimal cache aliasing properties in some cases.
2931
	 *
2932 2933 2934 2935
	 * For example if 2 tasks are alternately allocating
	 * batches of pages, one task can end up with a lot
	 * of pages of one half of the possible page colors
	 * and the other with pages of the other colors.
2936
	 */
2937
	batch = rounddown_pow_of_two(batch + batch/2) - 1;
2938

2939
	return batch;
2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956

#else
	/* The deferral and batching of frees should be suppressed under NOMMU
	 * conditions.
	 *
	 * The problem is that NOMMU needs to be able to allocate large chunks
	 * of contiguous memory as there's no hardware page translation to
	 * assemble apparent contiguous memory from discontiguous pages.
	 *
	 * Queueing large contiguous runs of pages for batching, however,
	 * causes the pages to actually be freed in smaller chunks.  As there
	 * can be a significant delay between the individual batches being
	 * recycled, this leads to the once large chunks of space being
	 * fragmented and becoming unavailable for high-order allocations.
	 */
	return 0;
#endif
2957 2958
}

A
Adrian Bunk 已提交
2959
static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
2960 2961 2962
{
	struct per_cpu_pages *pcp;

2963 2964
	memset(p, 0, sizeof(*p));

2965
	pcp = &p->pcp;
2966 2967 2968 2969 2970 2971
	pcp->count = 0;
	pcp->high = 6 * batch;
	pcp->batch = max(1UL, 1 * batch);
	INIT_LIST_HEAD(&pcp->list);
}

2972 2973 2974 2975 2976 2977 2978 2979 2980 2981
/*
 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
 * to the value high for the pageset p.
 */

static void setup_pagelist_highmark(struct per_cpu_pageset *p,
				unsigned long high)
{
	struct per_cpu_pages *pcp;

2982
	pcp = &p->pcp;
2983 2984 2985 2986 2987 2988 2989
	pcp->high = high;
	pcp->batch = max(1UL, high/4);
	if ((high/4) > (PAGE_SHIFT * 8))
		pcp->batch = PAGE_SHIFT * 8;
}


2990 2991
#ifdef CONFIG_NUMA
/*
2992 2993 2994 2995 2996 2997 2998
 * Boot pageset table. One per cpu which is going to be used for all
 * zones and all nodes. The parameters will be set in such a way
 * that an item put on a list will immediately be handed over to
 * the buddy list. This is safe since pageset manipulation is done
 * with interrupts disabled.
 *
 * Some NUMA counter updates may also be caught by the boot pagesets.
2999 3000 3001 3002 3003 3004 3005 3006
 *
 * The boot_pagesets must be kept even after bootup is complete for
 * unused processors and/or zones. They do play a role for bootstrapping
 * hotplugged processors.
 *
 * zoneinfo_show() and maybe other functions do
 * not check if the processor is online before following the pageset pointer.
 * Other parts of the kernel may not check if the zone is available.
3007
 */
3008
static struct per_cpu_pageset boot_pageset[NR_CPUS];
3009 3010 3011

/*
 * Dynamically allocate memory for the
3012 3013
 * per cpu pageset array in struct zone.
 */
3014
static int __cpuinit process_zones(int cpu)
3015 3016
{
	struct zone *zone, *dzone;
3017 3018 3019
	int node = cpu_to_node(cpu);

	node_set_state(node, N_CPU);	/* this node has a cpu */
3020

3021
	for_each_populated_zone(zone) {
N
Nick Piggin 已提交
3022
		zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset),
3023
					 GFP_KERNEL, node);
N
Nick Piggin 已提交
3024
		if (!zone_pcp(zone, cpu))
3025 3026
			goto bad;

N
Nick Piggin 已提交
3027
		setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone));
3028 3029 3030 3031

		if (percpu_pagelist_fraction)
			setup_pagelist_highmark(zone_pcp(zone, cpu),
			 	(zone->present_pages / percpu_pagelist_fraction));
3032 3033 3034 3035 3036
	}

	return 0;
bad:
	for_each_zone(dzone) {
3037 3038
		if (!populated_zone(dzone))
			continue;
3039 3040
		if (dzone == zone)
			break;
N
Nick Piggin 已提交
3041
		kfree(zone_pcp(dzone, cpu));
3042
		zone_pcp(dzone, cpu) = &boot_pageset[cpu];
3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053
	}
	return -ENOMEM;
}

static inline void free_zone_pagesets(int cpu)
{
	struct zone *zone;

	for_each_zone(zone) {
		struct per_cpu_pageset *pset = zone_pcp(zone, cpu);

3054 3055 3056
		/* Free per_cpu_pageset if it is slab allocated */
		if (pset != &boot_pageset[cpu])
			kfree(pset);
3057
		zone_pcp(zone, cpu) = &boot_pageset[cpu];
3058 3059 3060
	}
}

3061
static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb,
3062 3063 3064 3065 3066 3067 3068
		unsigned long action,
		void *hcpu)
{
	int cpu = (long)hcpu;
	int ret = NOTIFY_OK;

	switch (action) {
3069
	case CPU_UP_PREPARE:
3070
	case CPU_UP_PREPARE_FROZEN:
3071 3072 3073 3074
		if (process_zones(cpu))
			ret = NOTIFY_BAD;
		break;
	case CPU_UP_CANCELED:
3075
	case CPU_UP_CANCELED_FROZEN:
3076
	case CPU_DEAD:
3077
	case CPU_DEAD_FROZEN:
3078 3079 3080 3081
		free_zone_pagesets(cpu);
		break;
	default:
		break;
3082 3083 3084 3085
	}
	return ret;
}

3086
static struct notifier_block __cpuinitdata pageset_notifier =
3087 3088
	{ &pageset_cpuup_callback, NULL, 0 };

3089
void __init setup_per_cpu_pageset(void)
3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103
{
	int err;

	/* Initialize per_cpu_pageset for cpu 0.
	 * A cpuup callback will do this for every cpu
	 * as it comes online
	 */
	err = process_zones(smp_processor_id());
	BUG_ON(err);
	register_cpu_notifier(&pageset_notifier);
}

#endif

S
Sam Ravnborg 已提交
3104
static noinline __init_refok
3105
int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
3106 3107 3108
{
	int i;
	struct pglist_data *pgdat = zone->zone_pgdat;
3109
	size_t alloc_size;
3110 3111 3112 3113 3114

	/*
	 * The per-page waitqueue mechanism uses hashed waitqueues
	 * per zone.
	 */
3115 3116 3117 3118
	zone->wait_table_hash_nr_entries =
		 wait_table_hash_nr_entries(zone_size_pages);
	zone->wait_table_bits =
		wait_table_bits(zone->wait_table_hash_nr_entries);
3119 3120 3121
	alloc_size = zone->wait_table_hash_nr_entries
					* sizeof(wait_queue_head_t);

3122
	if (!slab_is_available()) {
3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135
		zone->wait_table = (wait_queue_head_t *)
			alloc_bootmem_node(pgdat, alloc_size);
	} else {
		/*
		 * This case means that a zone whose size was 0 gets new memory
		 * via memory hot-add.
		 * But it may be the case that a new node was hot-added.  In
		 * this case vmalloc() will not be able to use this new node's
		 * memory - this wait_table must be initialized to use this new
		 * node itself as well.
		 * To use this new node's memory, further consideration will be
		 * necessary.
		 */
3136
		zone->wait_table = vmalloc(alloc_size);
3137 3138 3139
	}
	if (!zone->wait_table)
		return -ENOMEM;
3140

3141
	for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
3142
		init_waitqueue_head(zone->wait_table + i);
3143 3144

	return 0;
3145 3146
}

3147
static __meminit void zone_pcp_init(struct zone *zone)
3148 3149 3150 3151 3152 3153 3154
{
	int cpu;
	unsigned long batch = zone_batchsize(zone);

	for (cpu = 0; cpu < NR_CPUS; cpu++) {
#ifdef CONFIG_NUMA
		/* Early boot. Slab allocator not functional yet */
N
Nick Piggin 已提交
3155
		zone_pcp(zone, cpu) = &boot_pageset[cpu];
3156 3157 3158 3159 3160
		setup_pageset(&boot_pageset[cpu],0);
#else
		setup_pageset(zone_pcp(zone,cpu), batch);
#endif
	}
A
Anton Blanchard 已提交
3161 3162 3163
	if (zone->present_pages)
		printk(KERN_DEBUG "  %s zone: %lu pages, LIFO batch:%lu\n",
			zone->name, zone->present_pages, batch);
3164 3165
}

3166 3167
__meminit int init_currently_empty_zone(struct zone *zone,
					unsigned long zone_start_pfn,
D
Dave Hansen 已提交
3168 3169
					unsigned long size,
					enum memmap_context context)
3170 3171
{
	struct pglist_data *pgdat = zone->zone_pgdat;
3172 3173 3174 3175
	int ret;
	ret = zone_wait_table_init(zone, size);
	if (ret)
		return ret;
3176 3177 3178 3179
	pgdat->nr_zones = zone_idx(zone) + 1;

	zone->zone_start_pfn = zone_start_pfn;

3180 3181 3182 3183 3184 3185
	mminit_dprintk(MMINIT_TRACE, "memmap_init",
			"Initialising map node %d zone %lu pfns %lu -> %lu\n",
			pgdat->node_id,
			(unsigned long)zone_idx(zone),
			zone_start_pfn, (zone_start_pfn + size));

3186
	zone_init_free_lists(zone);
3187 3188

	return 0;
3189 3190
}

3191 3192 3193 3194 3195
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
/*
 * Basic iterator support. Return the first range of PFNs for a node
 * Note: nid == MAX_NUMNODES returns first region regardless of node
 */
3196
static int __meminit first_active_region_index_in_nid(int nid)
3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208
{
	int i;

	for (i = 0; i < nr_nodemap_entries; i++)
		if (nid == MAX_NUMNODES || early_node_map[i].nid == nid)
			return i;

	return -1;
}

/*
 * Basic iterator support. Return the next active range of PFNs for a node
S
Simon Arlott 已提交
3209
 * Note: nid == MAX_NUMNODES returns next region regardless of node
3210
 */
3211
static int __meminit next_active_region_index_in_nid(int index, int nid)
3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226
{
	for (index = index + 1; index < nr_nodemap_entries; index++)
		if (nid == MAX_NUMNODES || early_node_map[index].nid == nid)
			return index;

	return -1;
}

#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
/*
 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
 * Architectures may implement their own version but if add_active_range()
 * was used and there are no special requirements, this is a convenient
 * alternative
 */
3227
int __meminit __early_pfn_to_nid(unsigned long pfn)
3228 3229 3230 3231 3232 3233 3234 3235 3236 3237
{
	int i;

	for (i = 0; i < nr_nodemap_entries; i++) {
		unsigned long start_pfn = early_node_map[i].start_pfn;
		unsigned long end_pfn = early_node_map[i].end_pfn;

		if (start_pfn <= pfn && pfn < end_pfn)
			return early_node_map[i].nid;
	}
3238 3239
	/* This is a memory hole */
	return -1;
3240 3241 3242
}
#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */

3243 3244
int __meminit early_pfn_to_nid(unsigned long pfn)
{
3245 3246 3247 3248 3249 3250 3251
	int nid;

	nid = __early_pfn_to_nid(pfn);
	if (nid >= 0)
		return nid;
	/* just returns 0 */
	return 0;
3252 3253
}

3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264
#ifdef CONFIG_NODES_SPAN_OTHER_NODES
bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
{
	int nid;

	nid = __early_pfn_to_nid(pfn);
	if (nid >= 0 && nid != node)
		return false;
	return true;
}
#endif
3265

3266 3267 3268 3269 3270 3271 3272
/* Basic iterator support to walk early_node_map[] */
#define for_each_active_range_index_in_nid(i, nid) \
	for (i = first_active_region_index_in_nid(nid); i != -1; \
				i = next_active_region_index_in_nid(i, nid))

/**
 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
3273 3274
 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300 3301
 *
 * If an architecture guarantees that all ranges registered with
 * add_active_ranges() contain no holes and may be freed, this
 * this function may be used instead of calling free_bootmem() manually.
 */
void __init free_bootmem_with_active_regions(int nid,
						unsigned long max_low_pfn)
{
	int i;

	for_each_active_range_index_in_nid(i, nid) {
		unsigned long size_pages = 0;
		unsigned long end_pfn = early_node_map[i].end_pfn;

		if (early_node_map[i].start_pfn >= max_low_pfn)
			continue;

		if (end_pfn > max_low_pfn)
			end_pfn = max_low_pfn;

		size_pages = end_pfn - early_node_map[i].start_pfn;
		free_bootmem_node(NODE_DATA(early_node_map[i].nid),
				PFN_PHYS(early_node_map[i].start_pfn),
				size_pages << PAGE_SHIFT);
	}
}

3302 3303 3304
void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data)
{
	int i;
3305
	int ret;
3306

3307 3308 3309 3310 3311 3312
	for_each_active_range_index_in_nid(i, nid) {
		ret = work_fn(early_node_map[i].start_pfn,
			      early_node_map[i].end_pfn, data);
		if (ret)
			break;
	}
3313
}
3314 3315
/**
 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3316
 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3317 3318 3319
 *
 * If an architecture guarantees that all ranges registered with
 * add_active_ranges() contain no holes and may be freed, this
3320
 * function may be used instead of calling memory_present() manually.
3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333
 */
void __init sparse_memory_present_with_active_regions(int nid)
{
	int i;

	for_each_active_range_index_in_nid(i, nid)
		memory_present(early_node_map[i].nid,
				early_node_map[i].start_pfn,
				early_node_map[i].end_pfn);
}

/**
 * get_pfn_range_for_nid - Return the start and end page frames for a node
3334 3335 3336
 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
3337 3338 3339 3340
 *
 * It returns the start and end page frame of a node based on information
 * provided by an arch calling add_active_range(). If called for a node
 * with no available memory, a warning is printed and the start and end
3341
 * PFNs will be 0.
3342
 */
3343
void __meminit get_pfn_range_for_nid(unsigned int nid,
3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354
			unsigned long *start_pfn, unsigned long *end_pfn)
{
	int i;
	*start_pfn = -1UL;
	*end_pfn = 0;

	for_each_active_range_index_in_nid(i, nid) {
		*start_pfn = min(*start_pfn, early_node_map[i].start_pfn);
		*end_pfn = max(*end_pfn, early_node_map[i].end_pfn);
	}

3355
	if (*start_pfn == -1UL)
3356 3357 3358
		*start_pfn = 0;
}

M
Mel Gorman 已提交
3359 3360 3361 3362 3363
/*
 * This finds a zone that can be used for ZONE_MOVABLE pages. The
 * assumption is made that zones within a node are ordered in monotonic
 * increasing memory addresses so that the "highest" populated zone is used
 */
A
Adrian Bunk 已提交
3364
static void __init find_usable_zone_for_movable(void)
M
Mel Gorman 已提交
3365 3366 3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389
{
	int zone_index;
	for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
		if (zone_index == ZONE_MOVABLE)
			continue;

		if (arch_zone_highest_possible_pfn[zone_index] >
				arch_zone_lowest_possible_pfn[zone_index])
			break;
	}

	VM_BUG_ON(zone_index == -1);
	movable_zone = zone_index;
}

/*
 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
 * because it is sized independant of architecture. Unlike the other zones,
 * the starting point for ZONE_MOVABLE is not fixed. It may be different
 * in each node depending on the size of each node and how evenly kernelcore
 * is distributed. This helper function adjusts the zone ranges
 * provided by the architecture for a given node by using the end of the
 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
 * zones within a node are in order of monotonic increases memory addresses
 */
A
Adrian Bunk 已提交
3390
static void __meminit adjust_zone_range_for_zone_movable(int nid,
M
Mel Gorman 已提交
3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415
					unsigned long zone_type,
					unsigned long node_start_pfn,
					unsigned long node_end_pfn,
					unsigned long *zone_start_pfn,
					unsigned long *zone_end_pfn)
{
	/* Only adjust if ZONE_MOVABLE is on this node */
	if (zone_movable_pfn[nid]) {
		/* Size ZONE_MOVABLE */
		if (zone_type == ZONE_MOVABLE) {
			*zone_start_pfn = zone_movable_pfn[nid];
			*zone_end_pfn = min(node_end_pfn,
				arch_zone_highest_possible_pfn[movable_zone]);

		/* Adjust for ZONE_MOVABLE starting within this range */
		} else if (*zone_start_pfn < zone_movable_pfn[nid] &&
				*zone_end_pfn > zone_movable_pfn[nid]) {
			*zone_end_pfn = zone_movable_pfn[nid];

		/* Check if this whole range is within ZONE_MOVABLE */
		} else if (*zone_start_pfn >= zone_movable_pfn[nid])
			*zone_start_pfn = *zone_end_pfn;
	}
}

3416 3417 3418 3419
/*
 * Return the number of pages a zone spans in a node, including holes
 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
 */
P
Paul Mundt 已提交
3420
static unsigned long __meminit zone_spanned_pages_in_node(int nid,
3421 3422 3423 3424 3425 3426 3427 3428 3429 3430
					unsigned long zone_type,
					unsigned long *ignored)
{
	unsigned long node_start_pfn, node_end_pfn;
	unsigned long zone_start_pfn, zone_end_pfn;

	/* Get the start and end of the node and zone */
	get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
	zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
	zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
M
Mel Gorman 已提交
3431 3432 3433
	adjust_zone_range_for_zone_movable(nid, zone_type,
				node_start_pfn, node_end_pfn,
				&zone_start_pfn, &zone_end_pfn);
3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448

	/* Check that this node has pages within the zone's required range */
	if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn)
		return 0;

	/* Move the zone boundaries inside the node if necessary */
	zone_end_pfn = min(zone_end_pfn, node_end_pfn);
	zone_start_pfn = max(zone_start_pfn, node_start_pfn);

	/* Return the spanned pages */
	return zone_end_pfn - zone_start_pfn;
}

/*
 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
3449
 * then all holes in the requested range will be accounted for.
3450
 */
A
Adrian Bunk 已提交
3451
static unsigned long __meminit __absent_pages_in_range(int nid,
3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463
				unsigned long range_start_pfn,
				unsigned long range_end_pfn)
{
	int i = 0;
	unsigned long prev_end_pfn = 0, hole_pages = 0;
	unsigned long start_pfn;

	/* Find the end_pfn of the first active range of pfns in the node */
	i = first_active_region_index_in_nid(nid);
	if (i == -1)
		return 0;

3464 3465
	prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);

3466 3467
	/* Account for ranges before physical memory on this node */
	if (early_node_map[i].start_pfn > range_start_pfn)
3468
		hole_pages = prev_end_pfn - range_start_pfn;
3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488

	/* Find all holes for the zone within the node */
	for (; i != -1; i = next_active_region_index_in_nid(i, nid)) {

		/* No need to continue if prev_end_pfn is outside the zone */
		if (prev_end_pfn >= range_end_pfn)
			break;

		/* Make sure the end of the zone is not within the hole */
		start_pfn = min(early_node_map[i].start_pfn, range_end_pfn);
		prev_end_pfn = max(prev_end_pfn, range_start_pfn);

		/* Update the hole size cound and move on */
		if (start_pfn > range_start_pfn) {
			BUG_ON(prev_end_pfn > start_pfn);
			hole_pages += start_pfn - prev_end_pfn;
		}
		prev_end_pfn = early_node_map[i].end_pfn;
	}

3489 3490
	/* Account for ranges past physical memory on this node */
	if (range_end_pfn > prev_end_pfn)
3491
		hole_pages += range_end_pfn -
3492 3493
				max(range_start_pfn, prev_end_pfn);

3494 3495 3496 3497 3498 3499 3500 3501
	return hole_pages;
}

/**
 * absent_pages_in_range - Return number of page frames in holes within a range
 * @start_pfn: The start PFN to start searching for holes
 * @end_pfn: The end PFN to stop searching for holes
 *
3502
 * It returns the number of pages frames in memory holes within a range.
3503 3504 3505 3506 3507 3508 3509 3510
 */
unsigned long __init absent_pages_in_range(unsigned long start_pfn,
							unsigned long end_pfn)
{
	return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
}

/* Return the number of page frames in holes in a zone on a node */
P
Paul Mundt 已提交
3511
static unsigned long __meminit zone_absent_pages_in_node(int nid,
3512 3513 3514
					unsigned long zone_type,
					unsigned long *ignored)
{
3515 3516 3517 3518 3519 3520 3521 3522 3523
	unsigned long node_start_pfn, node_end_pfn;
	unsigned long zone_start_pfn, zone_end_pfn;

	get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
	zone_start_pfn = max(arch_zone_lowest_possible_pfn[zone_type],
							node_start_pfn);
	zone_end_pfn = min(arch_zone_highest_possible_pfn[zone_type],
							node_end_pfn);

M
Mel Gorman 已提交
3524 3525 3526
	adjust_zone_range_for_zone_movable(nid, zone_type,
			node_start_pfn, node_end_pfn,
			&zone_start_pfn, &zone_end_pfn);
3527
	return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
3528
}
3529

3530
#else
P
Paul Mundt 已提交
3531
static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
3532 3533 3534 3535 3536 3537
					unsigned long zone_type,
					unsigned long *zones_size)
{
	return zones_size[zone_type];
}

P
Paul Mundt 已提交
3538
static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
3539 3540 3541 3542 3543 3544 3545 3546
						unsigned long zone_type,
						unsigned long *zholes_size)
{
	if (!zholes_size)
		return 0;

	return zholes_size[zone_type];
}
3547

3548 3549
#endif

3550
static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570
		unsigned long *zones_size, unsigned long *zholes_size)
{
	unsigned long realtotalpages, totalpages = 0;
	enum zone_type i;

	for (i = 0; i < MAX_NR_ZONES; i++)
		totalpages += zone_spanned_pages_in_node(pgdat->node_id, i,
								zones_size);
	pgdat->node_spanned_pages = totalpages;

	realtotalpages = totalpages;
	for (i = 0; i < MAX_NR_ZONES; i++)
		realtotalpages -=
			zone_absent_pages_in_node(pgdat->node_id, i,
								zholes_size);
	pgdat->node_present_pages = realtotalpages;
	printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
							realtotalpages);
}

3571 3572 3573
#ifndef CONFIG_SPARSEMEM
/*
 * Calculate the size of the zone->blockflags rounded to an unsigned long
3574 3575
 * Start by making sure zonesize is a multiple of pageblock_order by rounding
 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
3576 3577 3578 3579 3580 3581 3582
 * round what is now in bits to nearest long in bits, then return it in
 * bytes.
 */
static unsigned long __init usemap_size(unsigned long zonesize)
{
	unsigned long usemapsize;

3583 3584
	usemapsize = roundup(zonesize, pageblock_nr_pages);
	usemapsize = usemapsize >> pageblock_order;
3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595
	usemapsize *= NR_PAGEBLOCK_BITS;
	usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));

	return usemapsize / 8;
}

static void __init setup_usemap(struct pglist_data *pgdat,
				struct zone *zone, unsigned long zonesize)
{
	unsigned long usemapsize = usemap_size(zonesize);
	zone->pageblock_flags = NULL;
3596
	if (usemapsize)
3597 3598 3599 3600 3601 3602 3603
		zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize);
}
#else
static void inline setup_usemap(struct pglist_data *pgdat,
				struct zone *zone, unsigned long zonesize) {}
#endif /* CONFIG_SPARSEMEM */

3604
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3605 3606 3607 3608 3609 3610 3611 3612 3613 3614

/* Return a sensible default order for the pageblock size. */
static inline int pageblock_default_order(void)
{
	if (HPAGE_SHIFT > PAGE_SHIFT)
		return HUGETLB_PAGE_ORDER;

	return MAX_ORDER-1;
}

3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629
/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
static inline void __init set_pageblock_order(unsigned int order)
{
	/* Check that pageblock_nr_pages has not already been setup */
	if (pageblock_order)
		return;

	/*
	 * Assume the largest contiguous order of interest is a huge page.
	 * This value may be variable depending on boot parameters on IA64
	 */
	pageblock_order = order;
}
#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */

3630 3631 3632 3633 3634 3635 3636 3637 3638 3639
/*
 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
 * and pageblock_default_order() are unused as pageblock_order is set
 * at compile-time. See include/linux/pageblock-flags.h for the values of
 * pageblock_order based on the kernel config
 */
static inline int pageblock_default_order(unsigned int order)
{
	return MAX_ORDER-1;
}
3640 3641 3642 3643
#define set_pageblock_order(x)	do {} while (0)

#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */

L
Linus Torvalds 已提交
3644 3645 3646 3647 3648 3649
/*
 * Set up the zone data structures:
 *   - mark all pages reserved
 *   - mark all memory queues empty
 *   - clear the memory bitmaps
 */
3650
static void __paginginit free_area_init_core(struct pglist_data *pgdat,
L
Linus Torvalds 已提交
3651 3652
		unsigned long *zones_size, unsigned long *zholes_size)
{
3653
	enum zone_type j;
3654
	int nid = pgdat->node_id;
L
Linus Torvalds 已提交
3655
	unsigned long zone_start_pfn = pgdat->node_start_pfn;
3656
	int ret;
L
Linus Torvalds 已提交
3657

3658
	pgdat_resize_init(pgdat);
L
Linus Torvalds 已提交
3659 3660 3661
	pgdat->nr_zones = 0;
	init_waitqueue_head(&pgdat->kswapd_wait);
	pgdat->kswapd_max_order = 0;
3662
	pgdat_page_cgroup_init(pgdat);
L
Linus Torvalds 已提交
3663 3664 3665
	
	for (j = 0; j < MAX_NR_ZONES; j++) {
		struct zone *zone = pgdat->node_zones + j;
3666
		unsigned long size, realsize, memmap_pages;
3667
		enum lru_list l;
L
Linus Torvalds 已提交
3668

3669 3670 3671
		size = zone_spanned_pages_in_node(nid, j, zones_size);
		realsize = size - zone_absent_pages_in_node(nid, j,
								zholes_size);
L
Linus Torvalds 已提交
3672

3673 3674 3675 3676 3677
		/*
		 * Adjust realsize so that it accounts for how much memory
		 * is used by this zone for memmap. This affects the watermark
		 * and per-cpu initialisations
		 */
3678 3679
		memmap_pages =
			PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
3680 3681
		if (realsize >= memmap_pages) {
			realsize -= memmap_pages;
3682 3683 3684 3685
			if (memmap_pages)
				printk(KERN_DEBUG
				       "  %s zone: %lu pages used for memmap\n",
				       zone_names[j], memmap_pages);
3686 3687 3688 3689 3690
		} else
			printk(KERN_WARNING
				"  %s zone: %lu pages exceeds realsize %lu\n",
				zone_names[j], memmap_pages, realsize);

3691 3692
		/* Account for reserved pages */
		if (j == 0 && realsize > dma_reserve) {
3693
			realsize -= dma_reserve;
Y
Yinghai Lu 已提交
3694
			printk(KERN_DEBUG "  %s zone: %lu pages reserved\n",
3695
					zone_names[0], dma_reserve);
3696 3697
		}

3698
		if (!is_highmem_idx(j))
L
Linus Torvalds 已提交
3699 3700 3701 3702 3703
			nr_kernel_pages += realsize;
		nr_all_pages += realsize;

		zone->spanned_pages = size;
		zone->present_pages = realsize;
3704
#ifdef CONFIG_NUMA
3705
		zone->node = nid;
3706
		zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
3707
						/ 100;
3708
		zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
3709
#endif
L
Linus Torvalds 已提交
3710 3711 3712
		zone->name = zone_names[j];
		spin_lock_init(&zone->lock);
		spin_lock_init(&zone->lru_lock);
3713
		zone_seqlock_init(zone);
L
Linus Torvalds 已提交
3714 3715
		zone->zone_pgdat = pgdat;

3716
		zone->prev_priority = DEF_PRIORITY;
L
Linus Torvalds 已提交
3717

3718
		zone_pcp_init(zone);
3719 3720
		for_each_lru(l) {
			INIT_LIST_HEAD(&zone->lru[l].list);
3721
			zone->lru[l].nr_saved_scan = 0;
3722
		}
3723 3724 3725 3726
		zone->reclaim_stat.recent_rotated[0] = 0;
		zone->reclaim_stat.recent_rotated[1] = 0;
		zone->reclaim_stat.recent_scanned[0] = 0;
		zone->reclaim_stat.recent_scanned[1] = 0;
3727
		zap_zone_vm_stats(zone);
3728
		zone->flags = 0;
L
Linus Torvalds 已提交
3729 3730 3731
		if (!size)
			continue;

3732
		set_pageblock_order(pageblock_default_order());
3733
		setup_usemap(pgdat, zone, size);
D
Dave Hansen 已提交
3734 3735
		ret = init_currently_empty_zone(zone, zone_start_pfn,
						size, MEMMAP_EARLY);
3736
		BUG_ON(ret);
3737
		memmap_init(size, nid, j, zone_start_pfn);
L
Linus Torvalds 已提交
3738 3739 3740 3741
		zone_start_pfn += size;
	}
}

S
Sam Ravnborg 已提交
3742
static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
L
Linus Torvalds 已提交
3743 3744 3745 3746 3747
{
	/* Skip empty nodes */
	if (!pgdat->node_spanned_pages)
		return;

A
Andy Whitcroft 已提交
3748
#ifdef CONFIG_FLAT_NODE_MEM_MAP
L
Linus Torvalds 已提交
3749 3750
	/* ia64 gets its own node_mem_map, before this, without bootmem */
	if (!pgdat->node_mem_map) {
3751
		unsigned long size, start, end;
A
Andy Whitcroft 已提交
3752 3753
		struct page *map;

3754 3755 3756 3757 3758 3759 3760 3761 3762
		/*
		 * The zone's endpoints aren't required to be MAX_ORDER
		 * aligned but the node_mem_map endpoints must be in order
		 * for the buddy allocator to function correctly.
		 */
		start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
		end = pgdat->node_start_pfn + pgdat->node_spanned_pages;
		end = ALIGN(end, MAX_ORDER_NR_PAGES);
		size =  (end - start) * sizeof(struct page);
3763 3764 3765
		map = alloc_remap(pgdat->node_id, size);
		if (!map)
			map = alloc_bootmem_node(pgdat, size);
3766
		pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
L
Linus Torvalds 已提交
3767
	}
3768
#ifndef CONFIG_NEED_MULTIPLE_NODES
L
Linus Torvalds 已提交
3769 3770 3771
	/*
	 * With no DISCONTIG, the global mem_map is just set as node 0's
	 */
3772
	if (pgdat == NODE_DATA(0)) {
L
Linus Torvalds 已提交
3773
		mem_map = NODE_DATA(0)->node_mem_map;
3774 3775
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
		if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
3776
			mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
3777 3778
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
	}
L
Linus Torvalds 已提交
3779
#endif
A
Andy Whitcroft 已提交
3780
#endif /* CONFIG_FLAT_NODE_MEM_MAP */
L
Linus Torvalds 已提交
3781 3782
}

3783 3784
void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
		unsigned long node_start_pfn, unsigned long *zholes_size)
L
Linus Torvalds 已提交
3785
{
3786 3787
	pg_data_t *pgdat = NODE_DATA(nid);

L
Linus Torvalds 已提交
3788 3789
	pgdat->node_id = nid;
	pgdat->node_start_pfn = node_start_pfn;
3790
	calculate_node_totalpages(pgdat, zones_size, zholes_size);
L
Linus Torvalds 已提交
3791 3792

	alloc_node_mem_map(pgdat);
3793 3794 3795 3796 3797
#ifdef CONFIG_FLAT_NODE_MEM_MAP
	printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
		nid, (unsigned long)pgdat,
		(unsigned long)pgdat->node_mem_map);
#endif
L
Linus Torvalds 已提交
3798 3799 3800 3801

	free_area_init_core(pgdat, zones_size, zholes_size);
}

3802
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
M
Miklos Szeredi 已提交
3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 3817 3818 3819 3820 3821 3822

#if MAX_NUMNODES > 1
/*
 * Figure out the number of possible node ids.
 */
static void __init setup_nr_node_ids(void)
{
	unsigned int node;
	unsigned int highest = 0;

	for_each_node_mask(node, node_possible_map)
		highest = node;
	nr_node_ids = highest + 1;
}
#else
static inline void setup_nr_node_ids(void)
{
}
#endif

3823 3824 3825 3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839
/**
 * add_active_range - Register a range of PFNs backed by physical memory
 * @nid: The node ID the range resides on
 * @start_pfn: The start PFN of the available physical memory
 * @end_pfn: The end PFN of the available physical memory
 *
 * These ranges are stored in an early_node_map[] and later used by
 * free_area_init_nodes() to calculate zone sizes and holes. If the
 * range spans a memory hole, it is up to the architecture to ensure
 * the memory is not freed by the bootmem allocator. If possible
 * the range being registered will be merged with existing ranges.
 */
void __init add_active_range(unsigned int nid, unsigned long start_pfn,
						unsigned long end_pfn)
{
	int i;

3840 3841 3842 3843 3844
	mminit_dprintk(MMINIT_TRACE, "memory_register",
			"Entering add_active_range(%d, %#lx, %#lx) "
			"%d entries of %d used\n",
			nid, start_pfn, end_pfn,
			nr_nodemap_entries, MAX_ACTIVE_REGIONS);
3845

3846 3847
	mminit_validate_memmodel_limits(&start_pfn, &end_pfn);

3848 3849 3850 3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878 3879 3880 3881 3882 3883 3884 3885 3886
	/* Merge with existing active regions if possible */
	for (i = 0; i < nr_nodemap_entries; i++) {
		if (early_node_map[i].nid != nid)
			continue;

		/* Skip if an existing region covers this new one */
		if (start_pfn >= early_node_map[i].start_pfn &&
				end_pfn <= early_node_map[i].end_pfn)
			return;

		/* Merge forward if suitable */
		if (start_pfn <= early_node_map[i].end_pfn &&
				end_pfn > early_node_map[i].end_pfn) {
			early_node_map[i].end_pfn = end_pfn;
			return;
		}

		/* Merge backward if suitable */
		if (start_pfn < early_node_map[i].end_pfn &&
				end_pfn >= early_node_map[i].start_pfn) {
			early_node_map[i].start_pfn = start_pfn;
			return;
		}
	}

	/* Check that early_node_map is large enough */
	if (i >= MAX_ACTIVE_REGIONS) {
		printk(KERN_CRIT "More than %d memory regions, truncating\n",
							MAX_ACTIVE_REGIONS);
		return;
	}

	early_node_map[i].nid = nid;
	early_node_map[i].start_pfn = start_pfn;
	early_node_map[i].end_pfn = end_pfn;
	nr_nodemap_entries = i + 1;
}

/**
3887
 * remove_active_range - Shrink an existing registered range of PFNs
3888
 * @nid: The node id the range is on that should be shrunk
3889 3890
 * @start_pfn: The new PFN of the range
 * @end_pfn: The new PFN of the range
3891 3892
 *
 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
3893 3894 3895
 * The map is kept near the end physical page range that has already been
 * registered. This function allows an arch to shrink an existing registered
 * range.
3896
 */
3897 3898
void __init remove_active_range(unsigned int nid, unsigned long start_pfn,
				unsigned long end_pfn)
3899
{
3900 3901
	int i, j;
	int removed = 0;
3902

3903 3904 3905
	printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n",
			  nid, start_pfn, end_pfn);

3906
	/* Find the old active region end and shrink */
3907
	for_each_active_range_index_in_nid(i, nid) {
3908 3909
		if (early_node_map[i].start_pfn >= start_pfn &&
		    early_node_map[i].end_pfn <= end_pfn) {
3910
			/* clear it */
3911
			early_node_map[i].start_pfn = 0;
3912 3913 3914 3915
			early_node_map[i].end_pfn = 0;
			removed = 1;
			continue;
		}
3916 3917 3918 3919 3920 3921 3922 3923 3924 3925 3926 3927
		if (early_node_map[i].start_pfn < start_pfn &&
		    early_node_map[i].end_pfn > start_pfn) {
			unsigned long temp_end_pfn = early_node_map[i].end_pfn;
			early_node_map[i].end_pfn = start_pfn;
			if (temp_end_pfn > end_pfn)
				add_active_range(nid, end_pfn, temp_end_pfn);
			continue;
		}
		if (early_node_map[i].start_pfn >= start_pfn &&
		    early_node_map[i].end_pfn > end_pfn &&
		    early_node_map[i].start_pfn < end_pfn) {
			early_node_map[i].start_pfn = end_pfn;
3928
			continue;
3929
		}
3930 3931 3932 3933 3934 3935 3936 3937 3938 3939 3940 3941 3942 3943 3944 3945 3946 3947 3948
	}

	if (!removed)
		return;

	/* remove the blank ones */
	for (i = nr_nodemap_entries - 1; i > 0; i--) {
		if (early_node_map[i].nid != nid)
			continue;
		if (early_node_map[i].end_pfn)
			continue;
		/* we found it, get rid of it */
		for (j = i; j < nr_nodemap_entries - 1; j++)
			memcpy(&early_node_map[j], &early_node_map[j+1],
				sizeof(early_node_map[j]));
		j = nr_nodemap_entries - 1;
		memset(&early_node_map[j], 0, sizeof(early_node_map[j]));
		nr_nodemap_entries--;
	}
3949 3950 3951 3952
}

/**
 * remove_all_active_ranges - Remove all currently registered regions
3953
 *
3954 3955 3956 3957
 * During discovery, it may be found that a table like SRAT is invalid
 * and an alternative discovery method must be used. This function removes
 * all currently registered regions.
 */
3958
void __init remove_all_active_ranges(void)
3959 3960 3961 3962 3963 3964 3965 3966 3967 3968 3969 3970 3971 3972 3973 3974 3975 3976 3977 3978 3979 3980 3981 3982 3983 3984 3985 3986
{
	memset(early_node_map, 0, sizeof(early_node_map));
	nr_nodemap_entries = 0;
}

/* Compare two active node_active_regions */
static int __init cmp_node_active_region(const void *a, const void *b)
{
	struct node_active_region *arange = (struct node_active_region *)a;
	struct node_active_region *brange = (struct node_active_region *)b;

	/* Done this way to avoid overflows */
	if (arange->start_pfn > brange->start_pfn)
		return 1;
	if (arange->start_pfn < brange->start_pfn)
		return -1;

	return 0;
}

/* sort the node_map by start_pfn */
static void __init sort_node_map(void)
{
	sort(early_node_map, (size_t)nr_nodemap_entries,
			sizeof(struct node_active_region),
			cmp_node_active_region, NULL);
}

3987
/* Find the lowest pfn for a node */
A
Adrian Bunk 已提交
3988
static unsigned long __init find_min_pfn_for_node(int nid)
3989 3990
{
	int i;
3991
	unsigned long min_pfn = ULONG_MAX;
3992

3993 3994
	/* Assuming a sorted map, the first range found has the starting pfn */
	for_each_active_range_index_in_nid(i, nid)
3995
		min_pfn = min(min_pfn, early_node_map[i].start_pfn);
3996

3997 3998
	if (min_pfn == ULONG_MAX) {
		printk(KERN_WARNING
3999
			"Could not find start_pfn for node %d\n", nid);
4000 4001 4002 4003
		return 0;
	}

	return min_pfn;
4004 4005 4006 4007 4008 4009
}

/**
 * find_min_pfn_with_active_regions - Find the minimum PFN registered
 *
 * It returns the minimum PFN based on information provided via
4010
 * add_active_range().
4011 4012 4013 4014 4015 4016
 */
unsigned long __init find_min_pfn_with_active_regions(void)
{
	return find_min_pfn_for_node(MAX_NUMNODES);
}

4017 4018 4019 4020 4021
/*
 * early_calculate_totalpages()
 * Sum pages in active regions for movable zone.
 * Populate N_HIGH_MEMORY for calculating usable_nodes.
 */
A
Adrian Bunk 已提交
4022
static unsigned long __init early_calculate_totalpages(void)
4023 4024 4025 4026
{
	int i;
	unsigned long totalpages = 0;

4027 4028
	for (i = 0; i < nr_nodemap_entries; i++) {
		unsigned long pages = early_node_map[i].end_pfn -
4029
						early_node_map[i].start_pfn;
4030 4031 4032 4033 4034
		totalpages += pages;
		if (pages)
			node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
	}
  	return totalpages;
4035 4036
}

M
Mel Gorman 已提交
4037 4038 4039 4040 4041 4042
/*
 * Find the PFN the Movable zone begins in each node. Kernel memory
 * is spread evenly between nodes as long as the nodes have enough
 * memory. When they don't, some nodes will have more kernelcore than
 * others
 */
A
Adrian Bunk 已提交
4043
static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn)
M
Mel Gorman 已提交
4044 4045 4046 4047
{
	int i, nid;
	unsigned long usable_startpfn;
	unsigned long kernelcore_node, kernelcore_remaining;
4048 4049
	/* save the state before borrow the nodemask */
	nodemask_t saved_node_state = node_states[N_HIGH_MEMORY];
4050 4051
	unsigned long totalpages = early_calculate_totalpages();
	int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
M
Mel Gorman 已提交
4052

4053 4054 4055 4056 4057 4058 4059 4060 4061 4062 4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 4074
	/*
	 * If movablecore was specified, calculate what size of
	 * kernelcore that corresponds so that memory usable for
	 * any allocation type is evenly spread. If both kernelcore
	 * and movablecore are specified, then the value of kernelcore
	 * will be used for required_kernelcore if it's greater than
	 * what movablecore would have allowed.
	 */
	if (required_movablecore) {
		unsigned long corepages;

		/*
		 * Round-up so that ZONE_MOVABLE is at least as large as what
		 * was requested by the user
		 */
		required_movablecore =
			roundup(required_movablecore, MAX_ORDER_NR_PAGES);
		corepages = totalpages - required_movablecore;

		required_kernelcore = max(required_kernelcore, corepages);
	}

M
Mel Gorman 已提交
4075 4076
	/* If kernelcore was not specified, there is no ZONE_MOVABLE */
	if (!required_kernelcore)
4077
		goto out;
M
Mel Gorman 已提交
4078 4079 4080 4081 4082 4083 4084 4085

	/* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
	find_usable_zone_for_movable();
	usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];

restart:
	/* Spread kernelcore memory as evenly as possible throughout nodes */
	kernelcore_node = required_kernelcore / usable_nodes;
4086
	for_each_node_state(nid, N_HIGH_MEMORY) {
M
Mel Gorman 已提交
4087 4088 4089 4090 4091 4092 4093 4094 4095 4096 4097 4098 4099 4100 4101 4102 4103 4104 4105 4106 4107 4108 4109 4110 4111 4112 4113 4114 4115 4116 4117 4118 4119 4120 4121 4122 4123 4124 4125 4126 4127 4128 4129 4130 4131 4132 4133 4134 4135 4136 4137 4138 4139 4140 4141 4142 4143 4144 4145 4146 4147 4148 4149 4150 4151 4152 4153 4154 4155 4156 4157 4158 4159 4160 4161 4162 4163 4164 4165 4166 4167 4168 4169 4170 4171 4172 4173 4174 4175
		/*
		 * Recalculate kernelcore_node if the division per node
		 * now exceeds what is necessary to satisfy the requested
		 * amount of memory for the kernel
		 */
		if (required_kernelcore < kernelcore_node)
			kernelcore_node = required_kernelcore / usable_nodes;

		/*
		 * As the map is walked, we track how much memory is usable
		 * by the kernel using kernelcore_remaining. When it is
		 * 0, the rest of the node is usable by ZONE_MOVABLE
		 */
		kernelcore_remaining = kernelcore_node;

		/* Go through each range of PFNs within this node */
		for_each_active_range_index_in_nid(i, nid) {
			unsigned long start_pfn, end_pfn;
			unsigned long size_pages;

			start_pfn = max(early_node_map[i].start_pfn,
						zone_movable_pfn[nid]);
			end_pfn = early_node_map[i].end_pfn;
			if (start_pfn >= end_pfn)
				continue;

			/* Account for what is only usable for kernelcore */
			if (start_pfn < usable_startpfn) {
				unsigned long kernel_pages;
				kernel_pages = min(end_pfn, usable_startpfn)
								- start_pfn;

				kernelcore_remaining -= min(kernel_pages,
							kernelcore_remaining);
				required_kernelcore -= min(kernel_pages,
							required_kernelcore);

				/* Continue if range is now fully accounted */
				if (end_pfn <= usable_startpfn) {

					/*
					 * Push zone_movable_pfn to the end so
					 * that if we have to rebalance
					 * kernelcore across nodes, we will
					 * not double account here
					 */
					zone_movable_pfn[nid] = end_pfn;
					continue;
				}
				start_pfn = usable_startpfn;
			}

			/*
			 * The usable PFN range for ZONE_MOVABLE is from
			 * start_pfn->end_pfn. Calculate size_pages as the
			 * number of pages used as kernelcore
			 */
			size_pages = end_pfn - start_pfn;
			if (size_pages > kernelcore_remaining)
				size_pages = kernelcore_remaining;
			zone_movable_pfn[nid] = start_pfn + size_pages;

			/*
			 * Some kernelcore has been met, update counts and
			 * break if the kernelcore for this node has been
			 * satisified
			 */
			required_kernelcore -= min(required_kernelcore,
								size_pages);
			kernelcore_remaining -= size_pages;
			if (!kernelcore_remaining)
				break;
		}
	}

	/*
	 * If there is still required_kernelcore, we do another pass with one
	 * less node in the count. This will push zone_movable_pfn[nid] further
	 * along on the nodes that still have memory until kernelcore is
	 * satisified
	 */
	usable_nodes--;
	if (usable_nodes && required_kernelcore > usable_nodes)
		goto restart;

	/* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
	for (nid = 0; nid < MAX_NUMNODES; nid++)
		zone_movable_pfn[nid] =
			roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
4176 4177 4178 4179

out:
	/* restore the node_state */
	node_states[N_HIGH_MEMORY] = saved_node_state;
M
Mel Gorman 已提交
4180 4181
}

4182 4183 4184 4185 4186 4187 4188 4189 4190 4191 4192 4193 4194 4195
/* Any regular memory on that node ? */
static void check_for_regular_memory(pg_data_t *pgdat)
{
#ifdef CONFIG_HIGHMEM
	enum zone_type zone_type;

	for (zone_type = 0; zone_type <= ZONE_NORMAL; zone_type++) {
		struct zone *zone = &pgdat->node_zones[zone_type];
		if (zone->present_pages)
			node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY);
	}
#endif
}

4196 4197
/**
 * free_area_init_nodes - Initialise all pg_data_t and zone data
4198
 * @max_zone_pfn: an array of max PFNs for each zone
4199 4200 4201 4202 4203 4204 4205 4206 4207 4208 4209 4210 4211
 *
 * This will call free_area_init_node() for each active node in the system.
 * Using the page ranges provided by add_active_range(), the size of each
 * zone in each node and their holes is calculated. If the maximum PFN
 * between two adjacent zones match, it is assumed that the zone is empty.
 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
 * starts where the previous one ended. For example, ZONE_DMA32 starts
 * at arch_max_dma_pfn.
 */
void __init free_area_init_nodes(unsigned long *max_zone_pfn)
{
	unsigned long nid;
4212
	int i;
4213

4214 4215 4216
	/* Sort early_node_map as initialisation assumes it is sorted */
	sort_node_map();

4217 4218 4219 4220 4221 4222 4223 4224
	/* Record where the zone boundaries are */
	memset(arch_zone_lowest_possible_pfn, 0,
				sizeof(arch_zone_lowest_possible_pfn));
	memset(arch_zone_highest_possible_pfn, 0,
				sizeof(arch_zone_highest_possible_pfn));
	arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
	arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
	for (i = 1; i < MAX_NR_ZONES; i++) {
M
Mel Gorman 已提交
4225 4226
		if (i == ZONE_MOVABLE)
			continue;
4227 4228 4229 4230 4231
		arch_zone_lowest_possible_pfn[i] =
			arch_zone_highest_possible_pfn[i-1];
		arch_zone_highest_possible_pfn[i] =
			max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
	}
M
Mel Gorman 已提交
4232 4233 4234 4235 4236 4237
	arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
	arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;

	/* Find the PFNs that ZONE_MOVABLE begins at in each node */
	memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
	find_zone_movable_pfns_for_nodes(zone_movable_pfn);
4238 4239 4240

	/* Print out the zone ranges */
	printk("Zone PFN ranges:\n");
M
Mel Gorman 已提交
4241 4242 4243
	for (i = 0; i < MAX_NR_ZONES; i++) {
		if (i == ZONE_MOVABLE)
			continue;
4244
		printk("  %-8s %0#10lx -> %0#10lx\n",
4245 4246 4247
				zone_names[i],
				arch_zone_lowest_possible_pfn[i],
				arch_zone_highest_possible_pfn[i]);
M
Mel Gorman 已提交
4248 4249 4250 4251 4252 4253 4254 4255
	}

	/* Print out the PFNs ZONE_MOVABLE begins at in each node */
	printk("Movable zone start PFN for each node\n");
	for (i = 0; i < MAX_NUMNODES; i++) {
		if (zone_movable_pfn[i])
			printk("  Node %d: %lu\n", i, zone_movable_pfn[i]);
	}
4256 4257 4258 4259

	/* Print out the early_node_map[] */
	printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries);
	for (i = 0; i < nr_nodemap_entries; i++)
4260
		printk("  %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid,
4261 4262 4263 4264
						early_node_map[i].start_pfn,
						early_node_map[i].end_pfn);

	/* Initialise every node */
4265
	mminit_verify_pageflags_layout();
4266
	setup_nr_node_ids();
4267 4268
	for_each_online_node(nid) {
		pg_data_t *pgdat = NODE_DATA(nid);
4269
		free_area_init_node(nid, NULL,
4270
				find_min_pfn_for_node(nid), NULL);
4271 4272 4273 4274 4275

		/* Any memory on that node */
		if (pgdat->node_present_pages)
			node_set_state(nid, N_HIGH_MEMORY);
		check_for_regular_memory(pgdat);
4276 4277
	}
}
M
Mel Gorman 已提交
4278

4279
static int __init cmdline_parse_core(char *p, unsigned long *core)
M
Mel Gorman 已提交
4280 4281 4282 4283 4284 4285
{
	unsigned long long coremem;
	if (!p)
		return -EINVAL;

	coremem = memparse(p, &p);
4286
	*core = coremem >> PAGE_SHIFT;
M
Mel Gorman 已提交
4287

4288
	/* Paranoid check that UL is enough for the coremem value */
M
Mel Gorman 已提交
4289 4290 4291 4292
	WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);

	return 0;
}
M
Mel Gorman 已提交
4293

4294 4295 4296 4297 4298 4299 4300 4301 4302 4303 4304 4305 4306 4307 4308 4309 4310 4311
/*
 * kernelcore=size sets the amount of memory for use for allocations that
 * cannot be reclaimed or migrated.
 */
static int __init cmdline_parse_kernelcore(char *p)
{
	return cmdline_parse_core(p, &required_kernelcore);
}

/*
 * movablecore=size sets the amount of memory for use for allocations that
 * can be reclaimed or migrated.
 */
static int __init cmdline_parse_movablecore(char *p)
{
	return cmdline_parse_core(p, &required_movablecore);
}

M
Mel Gorman 已提交
4312
early_param("kernelcore", cmdline_parse_kernelcore);
4313
early_param("movablecore", cmdline_parse_movablecore);
M
Mel Gorman 已提交
4314

4315 4316
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */

4317
/**
4318 4319
 * set_dma_reserve - set the specified number of pages reserved in the first zone
 * @new_dma_reserve: The number of pages to mark reserved
4320 4321 4322 4323
 *
 * The per-cpu batchsize and zone watermarks are determined by present_pages.
 * In the DMA zone, a significant percentage may be consumed by kernel image
 * and other unfreeable allocations which can skew the watermarks badly. This
4324 4325 4326
 * function may optionally be used to account for unfreeable pages in the
 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
 * smaller per-cpu batchsize.
4327 4328 4329 4330 4331 4332
 */
void __init set_dma_reserve(unsigned long new_dma_reserve)
{
	dma_reserve = new_dma_reserve;
}

4333
#ifndef CONFIG_NEED_MULTIPLE_NODES
4334
struct pglist_data __refdata contig_page_data = { .bdata = &bootmem_node_data[0] };
L
Linus Torvalds 已提交
4335
EXPORT_SYMBOL(contig_page_data);
4336
#endif
L
Linus Torvalds 已提交
4337 4338 4339

void __init free_area_init(unsigned long *zones_size)
{
4340
	free_area_init_node(0, zones_size,
L
Linus Torvalds 已提交
4341 4342 4343 4344 4345 4346 4347 4348
			__pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
}

static int page_alloc_cpu_notify(struct notifier_block *self,
				 unsigned long action, void *hcpu)
{
	int cpu = (unsigned long)hcpu;

4349
	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
4350 4351 4352 4353 4354 4355 4356 4357
		drain_pages(cpu);

		/*
		 * Spill the event counters of the dead processor
		 * into the current processors event counters.
		 * This artificially elevates the count of the current
		 * processor.
		 */
4358
		vm_events_fold_cpu(cpu);
4359 4360 4361 4362 4363 4364 4365 4366

		/*
		 * Zero the differential counters of the dead processor
		 * so that the vm statistics are consistent.
		 *
		 * This is only okay since the processor is dead and cannot
		 * race with what we are doing.
		 */
4367
		refresh_cpu_vm_stats(cpu);
L
Linus Torvalds 已提交
4368 4369 4370 4371 4372 4373 4374 4375 4376
	}
	return NOTIFY_OK;
}

void __init page_alloc_init(void)
{
	hotcpu_notifier(page_alloc_cpu_notify, 0);
}

4377 4378 4379 4380 4381 4382 4383 4384
/*
 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
 *	or min_free_kbytes changes.
 */
static void calculate_totalreserve_pages(void)
{
	struct pglist_data *pgdat;
	unsigned long reserve_pages = 0;
4385
	enum zone_type i, j;
4386 4387 4388 4389 4390 4391 4392 4393 4394 4395 4396 4397

	for_each_online_pgdat(pgdat) {
		for (i = 0; i < MAX_NR_ZONES; i++) {
			struct zone *zone = pgdat->node_zones + i;
			unsigned long max = 0;

			/* Find valid and maximum lowmem_reserve in the zone */
			for (j = i; j < MAX_NR_ZONES; j++) {
				if (zone->lowmem_reserve[j] > max)
					max = zone->lowmem_reserve[j];
			}

4398 4399
			/* we treat the high watermark as reserved pages. */
			max += high_wmark_pages(zone);
4400 4401 4402 4403 4404 4405 4406 4407 4408

			if (max > zone->present_pages)
				max = zone->present_pages;
			reserve_pages += max;
		}
	}
	totalreserve_pages = reserve_pages;
}

L
Linus Torvalds 已提交
4409 4410 4411 4412 4413 4414 4415 4416 4417
/*
 * setup_per_zone_lowmem_reserve - called whenever
 *	sysctl_lower_zone_reserve_ratio changes.  Ensures that each zone
 *	has a correct pages reserved value, so an adequate number of
 *	pages are left in the zone after a successful __alloc_pages().
 */
static void setup_per_zone_lowmem_reserve(void)
{
	struct pglist_data *pgdat;
4418
	enum zone_type j, idx;
L
Linus Torvalds 已提交
4419

4420
	for_each_online_pgdat(pgdat) {
L
Linus Torvalds 已提交
4421 4422 4423 4424 4425 4426
		for (j = 0; j < MAX_NR_ZONES; j++) {
			struct zone *zone = pgdat->node_zones + j;
			unsigned long present_pages = zone->present_pages;

			zone->lowmem_reserve[j] = 0;

4427 4428
			idx = j;
			while (idx) {
L
Linus Torvalds 已提交
4429 4430
				struct zone *lower_zone;

4431 4432
				idx--;

L
Linus Torvalds 已提交
4433 4434 4435 4436 4437 4438 4439 4440 4441 4442
				if (sysctl_lowmem_reserve_ratio[idx] < 1)
					sysctl_lowmem_reserve_ratio[idx] = 1;

				lower_zone = pgdat->node_zones + idx;
				lower_zone->lowmem_reserve[j] = present_pages /
					sysctl_lowmem_reserve_ratio[idx];
				present_pages += lower_zone->present_pages;
			}
		}
	}
4443 4444 4445

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4446 4447
}

4448
/**
4449
 * setup_per_zone_wmarks - called when min_free_kbytes changes
4450
 * or when memory is hot-{added|removed}
4451
 *
4452 4453
 * Ensures that the watermark[min,low,high] values for each zone are set
 * correctly with respect to min_free_kbytes.
L
Linus Torvalds 已提交
4454
 */
4455
void setup_per_zone_wmarks(void)
L
Linus Torvalds 已提交
4456 4457 4458 4459 4460 4461 4462 4463 4464 4465 4466 4467 4468
{
	unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
	unsigned long lowmem_pages = 0;
	struct zone *zone;
	unsigned long flags;

	/* Calculate total number of !ZONE_HIGHMEM pages */
	for_each_zone(zone) {
		if (!is_highmem(zone))
			lowmem_pages += zone->present_pages;
	}

	for_each_zone(zone) {
4469 4470
		u64 tmp;

4471
		spin_lock_irqsave(&zone->lock, flags);
4472 4473
		tmp = (u64)pages_min * zone->present_pages;
		do_div(tmp, lowmem_pages);
L
Linus Torvalds 已提交
4474 4475
		if (is_highmem(zone)) {
			/*
N
Nick Piggin 已提交
4476 4477 4478 4479
			 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
			 * need highmem pages, so cap pages_min to a small
			 * value here.
			 *
4480
			 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
N
Nick Piggin 已提交
4481 4482
			 * deltas controls asynch page reclaim, and so should
			 * not be capped for highmem.
L
Linus Torvalds 已提交
4483 4484 4485 4486 4487 4488 4489 4490
			 */
			int min_pages;

			min_pages = zone->present_pages / 1024;
			if (min_pages < SWAP_CLUSTER_MAX)
				min_pages = SWAP_CLUSTER_MAX;
			if (min_pages > 128)
				min_pages = 128;
4491
			zone->watermark[WMARK_MIN] = min_pages;
L
Linus Torvalds 已提交
4492
		} else {
N
Nick Piggin 已提交
4493 4494
			/*
			 * If it's a lowmem zone, reserve a number of pages
L
Linus Torvalds 已提交
4495 4496
			 * proportionate to the zone's size.
			 */
4497
			zone->watermark[WMARK_MIN] = tmp;
L
Linus Torvalds 已提交
4498 4499
		}

4500 4501
		zone->watermark[WMARK_LOW]  = min_wmark_pages(zone) + (tmp >> 2);
		zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
4502
		setup_zone_migrate_reserve(zone);
4503
		spin_unlock_irqrestore(&zone->lock, flags);
L
Linus Torvalds 已提交
4504
	}
4505 4506 4507

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4508 4509
}

4510 4511 4512 4513 4514 4515 4516 4517 4518 4519 4520 4521 4522 4523 4524 4525 4526 4527 4528 4529 4530
/**
 * The inactive anon list should be small enough that the VM never has to
 * do too much work, but large enough that each inactive page has a chance
 * to be referenced again before it is swapped out.
 *
 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
 * INACTIVE_ANON pages on this zone's LRU, maintained by the
 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
 * the anonymous pages are kept on the inactive list.
 *
 * total     target    max
 * memory    ratio     inactive anon
 * -------------------------------------
 *   10MB       1         5MB
 *  100MB       1        50MB
 *    1GB       3       250MB
 *   10GB      10       0.9GB
 *  100GB      31         3GB
 *    1TB     101        10GB
 *   10TB     320        32GB
 */
4531
void calculate_zone_inactive_ratio(struct zone *zone)
4532
{
4533
	unsigned int gb, ratio;
4534

4535 4536 4537
	/* Zone size in gigabytes */
	gb = zone->present_pages >> (30 - PAGE_SHIFT);
	if (gb)
4538
		ratio = int_sqrt(10 * gb);
4539 4540
	else
		ratio = 1;
4541

4542 4543
	zone->inactive_ratio = ratio;
}
4544

4545 4546 4547 4548 4549 4550
static void __init setup_per_zone_inactive_ratio(void)
{
	struct zone *zone;

	for_each_zone(zone)
		calculate_zone_inactive_ratio(zone);
4551 4552
}

L
Linus Torvalds 已提交
4553 4554 4555 4556 4557 4558 4559 4560 4561 4562 4563 4564 4565 4566 4567 4568 4569 4570 4571 4572 4573 4574 4575 4576
/*
 * Initialise min_free_kbytes.
 *
 * For small machines we want it small (128k min).  For large machines
 * we want it large (64MB max).  But it is not linear, because network
 * bandwidth does not increase linearly with machine size.  We use
 *
 * 	min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
 *	min_free_kbytes = sqrt(lowmem_kbytes * 16)
 *
 * which yields
 *
 * 16MB:	512k
 * 32MB:	724k
 * 64MB:	1024k
 * 128MB:	1448k
 * 256MB:	2048k
 * 512MB:	2896k
 * 1024MB:	4096k
 * 2048MB:	5792k
 * 4096MB:	8192k
 * 8192MB:	11584k
 * 16384MB:	16384k
 */
4577
static int __init init_per_zone_wmark_min(void)
L
Linus Torvalds 已提交
4578 4579 4580 4581 4582 4583 4584 4585 4586 4587
{
	unsigned long lowmem_kbytes;

	lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);

	min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
	if (min_free_kbytes < 128)
		min_free_kbytes = 128;
	if (min_free_kbytes > 65536)
		min_free_kbytes = 65536;
4588
	setup_per_zone_wmarks();
L
Linus Torvalds 已提交
4589
	setup_per_zone_lowmem_reserve();
4590
	setup_per_zone_inactive_ratio();
L
Linus Torvalds 已提交
4591 4592
	return 0;
}
4593
module_init(init_per_zone_wmark_min)
L
Linus Torvalds 已提交
4594 4595 4596 4597 4598 4599 4600 4601 4602 4603

/*
 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so 
 *	that we can call two helper functions whenever min_free_kbytes
 *	changes.
 */
int min_free_kbytes_sysctl_handler(ctl_table *table, int write, 
	struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
{
	proc_dointvec(table, write, file, buffer, length, ppos);
4604
	if (write)
4605
		setup_per_zone_wmarks();
L
Linus Torvalds 已提交
4606 4607 4608
	return 0;
}

4609 4610 4611 4612 4613 4614 4615 4616 4617 4618 4619 4620
#ifdef CONFIG_NUMA
int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
	struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
{
	struct zone *zone;
	int rc;

	rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
	if (rc)
		return rc;

	for_each_zone(zone)
4621
		zone->min_unmapped_pages = (zone->present_pages *
4622 4623 4624
				sysctl_min_unmapped_ratio) / 100;
	return 0;
}
4625 4626 4627 4628 4629 4630 4631 4632 4633 4634 4635 4636 4637 4638 4639 4640

int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
	struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
{
	struct zone *zone;
	int rc;

	rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
	if (rc)
		return rc;

	for_each_zone(zone)
		zone->min_slab_pages = (zone->present_pages *
				sysctl_min_slab_ratio) / 100;
	return 0;
}
4641 4642
#endif

L
Linus Torvalds 已提交
4643 4644 4645 4646 4647 4648
/*
 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
 *	proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
 *	whenever sysctl_lowmem_reserve_ratio changes.
 *
 * The reserve ratio obviously has absolutely no relation with the
4649
 * minimum watermarks. The lowmem reserve ratio can only make sense
L
Linus Torvalds 已提交
4650 4651 4652 4653 4654 4655 4656 4657 4658 4659
 * if in function of the boot time zone sizes.
 */
int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
	struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
{
	proc_dointvec_minmax(table, write, file, buffer, length, ppos);
	setup_per_zone_lowmem_reserve();
	return 0;
}

4660 4661 4662 4663 4664 4665 4666 4667 4668 4669 4670 4671 4672 4673 4674 4675
/*
 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
 * cpu.  It is the fraction of total pages in each zone that a hot per cpu pagelist
 * can have before it gets flushed back to buddy allocator.
 */

int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
	struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
{
	struct zone *zone;
	unsigned int cpu;
	int ret;

	ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
	if (!write || (ret == -EINVAL))
		return ret;
4676
	for_each_populated_zone(zone) {
4677 4678 4679 4680 4681 4682 4683 4684 4685
		for_each_online_cpu(cpu) {
			unsigned long  high;
			high = zone->present_pages / percpu_pagelist_fraction;
			setup_pagelist_highmark(zone_pcp(zone, cpu), high);
		}
	}
	return 0;
}

4686
int hashdist = HASHDIST_DEFAULT;
L
Linus Torvalds 已提交
4687 4688 4689 4690 4691 4692 4693 4694 4695 4696 4697 4698 4699 4700 4701 4702 4703 4704 4705 4706 4707 4708 4709 4710 4711 4712 4713 4714 4715 4716 4717 4718 4719 4720

#ifdef CONFIG_NUMA
static int __init set_hashdist(char *str)
{
	if (!str)
		return 0;
	hashdist = simple_strtoul(str, &str, 0);
	return 1;
}
__setup("hashdist=", set_hashdist);
#endif

/*
 * allocate a large system hash table from bootmem
 * - it is assumed that the hash table must contain an exact power-of-2
 *   quantity of entries
 * - limit is the number of hash buckets, not the total allocation size
 */
void *__init alloc_large_system_hash(const char *tablename,
				     unsigned long bucketsize,
				     unsigned long numentries,
				     int scale,
				     int flags,
				     unsigned int *_hash_shift,
				     unsigned int *_hash_mask,
				     unsigned long limit)
{
	unsigned long long max = limit;
	unsigned long log2qty, size;
	void *table = NULL;

	/* allow the kernel cmdline to have a say */
	if (!numentries) {
		/* round applicable memory size up to nearest megabyte */
A
Andrew Morton 已提交
4721
		numentries = nr_kernel_pages;
L
Linus Torvalds 已提交
4722 4723 4724 4725 4726 4727 4728 4729 4730
		numentries += (1UL << (20 - PAGE_SHIFT)) - 1;
		numentries >>= 20 - PAGE_SHIFT;
		numentries <<= 20 - PAGE_SHIFT;

		/* limit to 1 bucket per 2^scale bytes of low memory */
		if (scale > PAGE_SHIFT)
			numentries >>= (scale - PAGE_SHIFT);
		else
			numentries <<= (PAGE_SHIFT - scale);
4731 4732 4733 4734

		/* Make sure we've got at least a 0-order allocation.. */
		if (unlikely((numentries * bucketsize) < PAGE_SIZE))
			numentries = PAGE_SIZE / bucketsize;
L
Linus Torvalds 已提交
4735
	}
4736
	numentries = roundup_pow_of_two(numentries);
L
Linus Torvalds 已提交
4737 4738 4739 4740 4741 4742 4743 4744 4745 4746

	/* limit allocation size to 1/16 total memory by default */
	if (max == 0) {
		max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
		do_div(max, bucketsize);
	}

	if (numentries > max)
		numentries = max;

4747
	log2qty = ilog2(numentries);
L
Linus Torvalds 已提交
4748 4749 4750 4751

	do {
		size = bucketsize << log2qty;
		if (flags & HASH_EARLY)
4752
			table = alloc_bootmem_nopanic(size);
L
Linus Torvalds 已提交
4753 4754 4755
		else if (hashdist)
			table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
		else {
4756 4757
			/*
			 * If bucketsize is not a power-of-two, we may free
4758 4759
			 * some pages at the end of hash table which
			 * alloc_pages_exact() automatically does
4760
			 */
4761
			if (get_order(size) < MAX_ORDER) {
4762
				table = alloc_pages_exact(size, GFP_ATOMIC);
4763 4764
				kmemleak_alloc(table, size, 1, GFP_ATOMIC);
			}
L
Linus Torvalds 已提交
4765 4766 4767 4768 4769 4770
		}
	} while (!table && size > PAGE_SIZE && --log2qty);

	if (!table)
		panic("Failed to allocate %s hash table\n", tablename);

4771
	printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n",
L
Linus Torvalds 已提交
4772 4773
	       tablename,
	       (1U << log2qty),
4774
	       ilog2(size) - PAGE_SHIFT,
L
Linus Torvalds 已提交
4775 4776 4777 4778 4779 4780 4781 4782 4783
	       size);

	if (_hash_shift)
		*_hash_shift = log2qty;
	if (_hash_mask)
		*_hash_mask = (1 << log2qty) - 1;

	return table;
}
4784

4785 4786 4787 4788 4789 4790 4791 4792 4793 4794 4795 4796 4797 4798 4799
/* Return a pointer to the bitmap storing bits affecting a block of pages */
static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
							unsigned long pfn)
{
#ifdef CONFIG_SPARSEMEM
	return __pfn_to_section(pfn)->pageblock_flags;
#else
	return zone->pageblock_flags;
#endif /* CONFIG_SPARSEMEM */
}

static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
{
#ifdef CONFIG_SPARSEMEM
	pfn &= (PAGES_PER_SECTION-1);
4800
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4801 4802
#else
	pfn = pfn - zone->zone_start_pfn;
4803
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4804 4805 4806 4807
#endif /* CONFIG_SPARSEMEM */
}

/**
4808
 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
4809 4810 4811 4812 4813 4814 4815 4816 4817 4818 4819 4820 4821 4822 4823 4824 4825 4826 4827 4828 4829 4830
 * @page: The page within the block of interest
 * @start_bitidx: The first bit of interest to retrieve
 * @end_bitidx: The last bit of interest
 * returns pageblock_bits flags
 */
unsigned long get_pageblock_flags_group(struct page *page,
					int start_bitidx, int end_bitidx)
{
	struct zone *zone;
	unsigned long *bitmap;
	unsigned long pfn, bitidx;
	unsigned long flags = 0;
	unsigned long value = 1;

	zone = page_zone(page);
	pfn = page_to_pfn(page);
	bitmap = get_pageblock_bitmap(zone, pfn);
	bitidx = pfn_to_bitidx(zone, pfn);

	for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
		if (test_bit(bitidx + start_bitidx, bitmap))
			flags |= value;
4831

4832 4833 4834 4835
	return flags;
}

/**
4836
 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
4837 4838 4839 4840 4841 4842 4843 4844 4845 4846 4847 4848 4849 4850 4851 4852 4853
 * @page: The page within the block of interest
 * @start_bitidx: The first bit of interest
 * @end_bitidx: The last bit of interest
 * @flags: The flags to set
 */
void set_pageblock_flags_group(struct page *page, unsigned long flags,
					int start_bitidx, int end_bitidx)
{
	struct zone *zone;
	unsigned long *bitmap;
	unsigned long pfn, bitidx;
	unsigned long value = 1;

	zone = page_zone(page);
	pfn = page_to_pfn(page);
	bitmap = get_pageblock_bitmap(zone, pfn);
	bitidx = pfn_to_bitidx(zone, pfn);
4854 4855
	VM_BUG_ON(pfn < zone->zone_start_pfn);
	VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
4856 4857 4858 4859 4860 4861 4862

	for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
		if (flags & value)
			__set_bit(bitidx + start_bitidx, bitmap);
		else
			__clear_bit(bitidx + start_bitidx, bitmap);
}
K
KAMEZAWA Hiroyuki 已提交
4863 4864 4865 4866 4867 4868 4869 4870 4871 4872 4873 4874 4875 4876 4877 4878 4879 4880 4881 4882 4883 4884 4885 4886 4887 4888

/*
 * This is designed as sub function...plz see page_isolation.c also.
 * set/clear page block's type to be ISOLATE.
 * page allocater never alloc memory from ISOLATE block.
 */

int set_migratetype_isolate(struct page *page)
{
	struct zone *zone;
	unsigned long flags;
	int ret = -EBUSY;

	zone = page_zone(page);
	spin_lock_irqsave(&zone->lock, flags);
	/*
	 * In future, more migrate types will be able to be isolation target.
	 */
	if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE)
		goto out;
	set_pageblock_migratetype(page, MIGRATE_ISOLATE);
	move_freepages_block(zone, page, MIGRATE_ISOLATE);
	ret = 0;
out:
	spin_unlock_irqrestore(&zone->lock, flags);
	if (!ret)
4889
		drain_all_pages();
K
KAMEZAWA Hiroyuki 已提交
4890 4891 4892 4893 4894 4895 4896 4897 4898 4899 4900 4901 4902 4903 4904 4905
	return ret;
}

void unset_migratetype_isolate(struct page *page)
{
	struct zone *zone;
	unsigned long flags;
	zone = page_zone(page);
	spin_lock_irqsave(&zone->lock, flags);
	if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
		goto out;
	set_pageblock_migratetype(page, MIGRATE_MOVABLE);
	move_freepages_block(zone, page, MIGRATE_MOVABLE);
out:
	spin_unlock_irqrestore(&zone->lock, flags);
}
K
KAMEZAWA Hiroyuki 已提交
4906 4907 4908 4909 4910 4911 4912 4913 4914 4915 4916 4917 4918 4919 4920 4921 4922 4923 4924 4925 4926 4927 4928 4929 4930 4931 4932 4933 4934 4935 4936 4937 4938 4939 4940 4941 4942 4943 4944 4945 4946 4947 4948 4949 4950 4951 4952

#ifdef CONFIG_MEMORY_HOTREMOVE
/*
 * All pages in the range must be isolated before calling this.
 */
void
__offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
{
	struct page *page;
	struct zone *zone;
	int order, i;
	unsigned long pfn;
	unsigned long flags;
	/* find the first valid pfn */
	for (pfn = start_pfn; pfn < end_pfn; pfn++)
		if (pfn_valid(pfn))
			break;
	if (pfn == end_pfn)
		return;
	zone = page_zone(pfn_to_page(pfn));
	spin_lock_irqsave(&zone->lock, flags);
	pfn = start_pfn;
	while (pfn < end_pfn) {
		if (!pfn_valid(pfn)) {
			pfn++;
			continue;
		}
		page = pfn_to_page(pfn);
		BUG_ON(page_count(page));
		BUG_ON(!PageBuddy(page));
		order = page_order(page);
#ifdef CONFIG_DEBUG_VM
		printk(KERN_INFO "remove from free list %lx %d %lx\n",
		       pfn, 1 << order, end_pfn);
#endif
		list_del(&page->lru);
		rmv_page_order(page);
		zone->free_area[order].nr_free--;
		__mod_zone_page_state(zone, NR_FREE_PAGES,
				      - (1UL << order));
		for (i = 0; i < (1 << order); i++)
			SetPageReserved((page+i));
		pfn += (1 << order);
	}
	spin_unlock_irqrestore(&zone->lock, flags);
}
#endif