page_alloc.c 88.4 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 22 23
/*
 *  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>
#include <linux/bootmem.h>
#include <linux/compiler.h>
24
#include <linux/kernel.h>
L
Linus Torvalds 已提交
25 26 27 28 29 30 31 32 33 34
#include <linux/module.h>
#include <linux/suspend.h>
#include <linux/pagevec.h>
#include <linux/blkdev.h>
#include <linux/slab.h>
#include <linux/notifier.h>
#include <linux/topology.h>
#include <linux/sysctl.h>
#include <linux/cpu.h>
#include <linux/cpuset.h>
35
#include <linux/memory_hotplug.h>
L
Linus Torvalds 已提交
36 37
#include <linux/nodemask.h>
#include <linux/vmalloc.h>
38
#include <linux/mempolicy.h>
39
#include <linux/stop_machine.h>
40 41
#include <linux/sort.h>
#include <linux/pfn.h>
42
#include <linux/backing-dev.h>
L
Linus Torvalds 已提交
43 44

#include <asm/tlbflush.h>
45
#include <asm/div64.h>
L
Linus Torvalds 已提交
46 47 48 49 50 51
#include "internal.h"

/*
 * MCD - HACK: Find somewhere to initialize this EARLY, or make this
 * initializer cleaner
 */
52
nodemask_t node_online_map __read_mostly = { { [0] = 1UL } };
53
EXPORT_SYMBOL(node_online_map);
54
nodemask_t node_possible_map __read_mostly = NODE_MASK_ALL;
55
EXPORT_SYMBOL(node_possible_map);
56
unsigned long totalram_pages __read_mostly;
57
unsigned long totalreserve_pages __read_mostly;
L
Linus Torvalds 已提交
58
long nr_swap_pages;
59
int percpu_pagelist_fraction;
L
Linus Torvalds 已提交
60

61
static void __free_pages_ok(struct page *page, unsigned int order);
62

L
Linus Torvalds 已提交
63 64 65 66 67 68 69
/*
 * 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
70 71 72
 *
 * 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
73
 */
74 75
int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
	 256,
76
#ifdef CONFIG_ZONE_DMA32
77
	 256,
78
#endif
79
#ifdef CONFIG_HIGHMEM
80
	 32
81
#endif
82
};
L
Linus Torvalds 已提交
83 84 85

EXPORT_SYMBOL(totalram_pages);

86 87
static char *zone_names[MAX_NR_ZONES] = {
	 "DMA",
88
#ifdef CONFIG_ZONE_DMA32
89
	 "DMA32",
90
#endif
91
	 "Normal",
92
#ifdef CONFIG_HIGHMEM
93
	 "HighMem"
94
#endif
95 96
};

L
Linus Torvalds 已提交
97 98
int min_free_kbytes = 1024;

99 100
unsigned long __meminitdata nr_kernel_pages;
unsigned long __meminitdata nr_all_pages;
101
static unsigned long __initdata dma_reserve;
L
Linus Torvalds 已提交
102

103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
  /*
   * MAX_ACTIVE_REGIONS determines the maxmimum number of distinct
   * 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

  struct node_active_region __initdata early_node_map[MAX_ACTIVE_REGIONS];
  int __initdata nr_nodemap_entries;
  unsigned long __initdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
  unsigned long __initdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
128 129 130 131
#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
  unsigned long __initdata node_boundary_start_pfn[MAX_NUMNODES];
  unsigned long __initdata node_boundary_end_pfn[MAX_NUMNODES];
#endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
132 133
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */

N
Nick Piggin 已提交
134
#ifdef CONFIG_DEBUG_VM
135
static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
L
Linus Torvalds 已提交
136
{
137 138 139
	int ret = 0;
	unsigned seq;
	unsigned long pfn = page_to_pfn(page);
140

141 142 143 144 145 146 147 148 149
	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;
150 151 152 153
}

static int page_is_consistent(struct zone *zone, struct page *page)
{
L
Linus Torvalds 已提交
154 155
#ifdef CONFIG_HOLES_IN_ZONE
	if (!pfn_valid(page_to_pfn(page)))
156
		return 0;
L
Linus Torvalds 已提交
157 158
#endif
	if (zone != page_zone(page))
159 160 161 162 163 164 165 166 167 168
		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
169
		return 1;
170 171 172
	if (!page_is_consistent(zone, page))
		return 1;

L
Linus Torvalds 已提交
173 174
	return 0;
}
N
Nick Piggin 已提交
175 176 177 178 179 180 181
#else
static inline int bad_range(struct zone *zone, struct page *page)
{
	return 0;
}
#endif

N
Nick Piggin 已提交
182
static void bad_page(struct page *page)
L
Linus Torvalds 已提交
183
{
N
Nick Piggin 已提交
184
	printk(KERN_EMERG "Bad page state in process '%s'\n"
185 186 187
		KERN_EMERG "page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n"
		KERN_EMERG "Trying to fix it up, but a reboot is needed\n"
		KERN_EMERG "Backtrace:\n",
N
Nick Piggin 已提交
188 189 190
		current->comm, page, (int)(2*sizeof(unsigned long)),
		(unsigned long)page->flags, page->mapping,
		page_mapcount(page), page_count(page));
L
Linus Torvalds 已提交
191
	dump_stack();
192 193
	page->flags &= ~(1 << PG_lru	|
			1 << PG_private |
L
Linus Torvalds 已提交
194 195 196
			1 << PG_locked	|
			1 << PG_active	|
			1 << PG_dirty	|
197 198
			1 << PG_reclaim |
			1 << PG_slab    |
L
Linus Torvalds 已提交
199
			1 << PG_swapcache |
200 201
			1 << PG_writeback |
			1 << PG_buddy );
L
Linus Torvalds 已提交
202 203 204
	set_page_count(page, 0);
	reset_page_mapcount(page);
	page->mapping = NULL;
205
	add_taint(TAINT_BAD_PAGE);
L
Linus Torvalds 已提交
206 207 208 209 210 211 212 213 214 215 216 217
}

/*
 * 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).
 *
218 219 220
 * 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
221
 */
222 223 224 225 226 227

static void free_compound_page(struct page *page)
{
	__free_pages_ok(page, (unsigned long)page[1].lru.prev);
}

L
Linus Torvalds 已提交
228 229 230 231 232
static void prep_compound_page(struct page *page, unsigned long order)
{
	int i;
	int nr_pages = 1 << order;

233
	page[1].lru.next = (void *)free_compound_page;	/* set dtor */
234
	page[1].lru.prev = (void *)order;
L
Linus Torvalds 已提交
235 236 237
	for (i = 0; i < nr_pages; i++) {
		struct page *p = page + i;

238
		__SetPageCompound(p);
H
Hugh Dickins 已提交
239
		set_page_private(p, (unsigned long)page);
L
Linus Torvalds 已提交
240 241 242 243 244 245 246 247
	}
}

static void destroy_compound_page(struct page *page, unsigned long order)
{
	int i;
	int nr_pages = 1 << order;

248
	if (unlikely((unsigned long)page[1].lru.prev != order))
N
Nick Piggin 已提交
249
		bad_page(page);
L
Linus Torvalds 已提交
250 251 252 253

	for (i = 0; i < nr_pages; i++) {
		struct page *p = page + i;

N
Nick Piggin 已提交
254 255 256
		if (unlikely(!PageCompound(p) |
				(page_private(p) != (unsigned long)page)))
			bad_page(page);
257
		__ClearPageCompound(p);
L
Linus Torvalds 已提交
258 259 260
	}
}

N
Nick Piggin 已提交
261 262 263 264
static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
{
	int i;

N
Nick Piggin 已提交
265
	VM_BUG_ON((gfp_flags & (__GFP_WAIT | __GFP_HIGHMEM)) == __GFP_HIGHMEM);
266 267 268 269
	/*
	 * 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
270
	VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt());
N
Nick Piggin 已提交
271 272 273 274
	for (i = 0; i < (1 << order); i++)
		clear_highpage(page + i);
}

L
Linus Torvalds 已提交
275 276 277 278 279
/*
 * function for dealing with page's order in buddy system.
 * zone->lock is already acquired when we use these.
 * So, we don't need atomic page->flags operations here.
 */
280 281
static inline unsigned long page_order(struct page *page)
{
H
Hugh Dickins 已提交
282
	return page_private(page);
L
Linus Torvalds 已提交
283 284
}

285 286
static inline void set_page_order(struct page *page, int order)
{
H
Hugh Dickins 已提交
287
	set_page_private(page, order);
288
	__SetPageBuddy(page);
L
Linus Torvalds 已提交
289 290 291 292
}

static inline void rmv_page_order(struct page *page)
{
293
	__ClearPageBuddy(page);
H
Hugh Dickins 已提交
294
	set_page_private(page, 0);
L
Linus Torvalds 已提交
295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311
}

/*
 * 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
312
 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
L
Linus Torvalds 已提交
313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330
 */
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
331
 * (a) the buddy is not in a hole &&
332
 * (b) the buddy is in the buddy system &&
333 334
 * (c) a page and its buddy have the same order &&
 * (d) a page and its buddy are in the same zone.
335 336 337
 *
 * 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
338
 *
339
 * For recording page's order, we use page_private(page).
L
Linus Torvalds 已提交
340
 */
341 342
static inline int page_is_buddy(struct page *page, struct page *buddy,
								int order)
L
Linus Torvalds 已提交
343
{
N
Nick Piggin 已提交
344
#ifdef CONFIG_HOLES_IN_ZONE
345
	if (!pfn_valid(page_to_pfn(buddy)))
N
Nick Piggin 已提交
346 347 348
		return 0;
#endif

349 350 351 352 353
	if (page_zone_id(page) != page_zone_id(buddy))
		return 0;

	if (PageBuddy(buddy) && page_order(buddy) == order) {
		BUG_ON(page_count(buddy) != 0);
354
		return 1;
355
	}
356
	return 0;
L
Linus Torvalds 已提交
357 358 359 360 361 362 363 364 365 366 367 368 369 370 371
}

/*
 * 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
372
 * free pages of length of (1 << order) and marked with PG_buddy. Page's
H
Hugh Dickins 已提交
373
 * order is recorded in page_private(page) field.
L
Linus Torvalds 已提交
374 375 376 377 378 379 380 381 382
 * 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
383
static inline void __free_one_page(struct page *page,
L
Linus Torvalds 已提交
384 385 386 387 388
		struct zone *zone, unsigned int order)
{
	unsigned long page_idx;
	int order_size = 1 << order;

N
Nick Piggin 已提交
389
	if (unlikely(PageCompound(page)))
L
Linus Torvalds 已提交
390 391 392 393
		destroy_compound_page(page, order);

	page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);

N
Nick Piggin 已提交
394 395
	VM_BUG_ON(page_idx & (order_size - 1));
	VM_BUG_ON(bad_range(zone, page));
L
Linus Torvalds 已提交
396 397 398 399 400 401 402 403

	zone->free_pages += order_size;
	while (order < MAX_ORDER-1) {
		unsigned long combined_idx;
		struct free_area *area;
		struct page *buddy;

		buddy = __page_find_buddy(page, page_idx, order);
404
		if (!page_is_buddy(page, buddy, order))
L
Linus Torvalds 已提交
405
			break;		/* Move the buddy up one level. */
N
Nick Piggin 已提交
406

L
Linus Torvalds 已提交
407 408 409 410
		list_del(&buddy->lru);
		area = zone->free_area + order;
		area->nr_free--;
		rmv_page_order(buddy);
N
Nick Piggin 已提交
411
		combined_idx = __find_combined_index(page_idx, order);
L
Linus Torvalds 已提交
412 413 414 415 416 417 418 419 420
		page = page + (combined_idx - page_idx);
		page_idx = combined_idx;
		order++;
	}
	set_page_order(page, order);
	list_add(&page->lru, &zone->free_area[order].free_list);
	zone->free_area[order].nr_free++;
}

N
Nick Piggin 已提交
421
static inline int free_pages_check(struct page *page)
L
Linus Torvalds 已提交
422
{
N
Nick Piggin 已提交
423 424 425
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
		(page_count(page) != 0)  |
L
Linus Torvalds 已提交
426 427 428 429 430 431 432 433
		(page->flags & (
			1 << PG_lru	|
			1 << PG_private |
			1 << PG_locked	|
			1 << PG_active	|
			1 << PG_reclaim	|
			1 << PG_slab	|
			1 << PG_swapcache |
N
Nick Piggin 已提交
434
			1 << PG_writeback |
435 436
			1 << PG_reserved |
			1 << PG_buddy ))))
N
Nick Piggin 已提交
437
		bad_page(page);
L
Linus Torvalds 已提交
438
	if (PageDirty(page))
N
Nick Piggin 已提交
439
		__ClearPageDirty(page);
440 441 442 443 444 445
	/*
	 * For now, we report if PG_reserved was found set, but do not
	 * clear it, and do not free the page.  But we shall soon need
	 * to do more, for when the ZERO_PAGE count wraps negative.
	 */
	return PageReserved(page);
L
Linus Torvalds 已提交
446 447 448 449 450
}

/*
 * Frees a list of pages. 
 * Assumes all pages on list are in same zone, and of same order.
451
 * count is the number of pages to free.
L
Linus Torvalds 已提交
452 453 454 455 456 457 458
 *
 * 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
459 460
static void free_pages_bulk(struct zone *zone, int count,
					struct list_head *list, int order)
L
Linus Torvalds 已提交
461
{
N
Nick Piggin 已提交
462
	spin_lock(&zone->lock);
L
Linus Torvalds 已提交
463 464
	zone->all_unreclaimable = 0;
	zone->pages_scanned = 0;
N
Nick Piggin 已提交
465 466 467
	while (count--) {
		struct page *page;

N
Nick Piggin 已提交
468
		VM_BUG_ON(list_empty(list));
L
Linus Torvalds 已提交
469
		page = list_entry(list->prev, struct page, lru);
N
Nick Piggin 已提交
470
		/* have to delete it as __free_one_page list manipulates */
L
Linus Torvalds 已提交
471
		list_del(&page->lru);
N
Nick Piggin 已提交
472
		__free_one_page(page, zone, order);
L
Linus Torvalds 已提交
473
	}
N
Nick Piggin 已提交
474
	spin_unlock(&zone->lock);
L
Linus Torvalds 已提交
475 476
}

N
Nick Piggin 已提交
477
static void free_one_page(struct zone *zone, struct page *page, int order)
L
Linus Torvalds 已提交
478
{
479 480 481
	spin_lock(&zone->lock);
	zone->all_unreclaimable = 0;
	zone->pages_scanned = 0;
482
	__free_one_page(page, zone, order);
483
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
484 485 486 487 488
}

static void __free_pages_ok(struct page *page, unsigned int order)
{
	unsigned long flags;
L
Linus Torvalds 已提交
489
	int i;
490
	int reserved = 0;
L
Linus Torvalds 已提交
491 492

	for (i = 0 ; i < (1 << order) ; ++i)
N
Nick Piggin 已提交
493
		reserved += free_pages_check(page + i);
494 495 496
	if (reserved)
		return;

N
Nick Piggin 已提交
497 498
	if (!PageHighMem(page))
		debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
N
Nick Piggin 已提交
499
	arch_free_page(page, order);
N
Nick Piggin 已提交
500
	kernel_map_pages(page, 1 << order, 0);
N
Nick Piggin 已提交
501

N
Nick Piggin 已提交
502
	local_irq_save(flags);
503
	__count_vm_events(PGFREE, 1 << order);
N
Nick Piggin 已提交
504
	free_one_page(page_zone(page), page, order);
N
Nick Piggin 已提交
505
	local_irq_restore(flags);
L
Linus Torvalds 已提交
506 507
}

508 509 510 511 512 513 514 515
/*
 * permit the bootmem allocator to evade page validation on high-order frees
 */
void fastcall __init __free_pages_bootmem(struct page *page, unsigned int order)
{
	if (order == 0) {
		__ClearPageReserved(page);
		set_page_count(page, 0);
516
		set_page_refcounted(page);
N
Nick Piggin 已提交
517
		__free_page(page);
518 519 520
	} else {
		int loop;

N
Nick Piggin 已提交
521
		prefetchw(page);
522 523 524
		for (loop = 0; loop < BITS_PER_LONG; loop++) {
			struct page *p = &page[loop];

N
Nick Piggin 已提交
525 526
			if (loop + 1 < BITS_PER_LONG)
				prefetchw(p + 1);
527 528 529 530
			__ClearPageReserved(p);
			set_page_count(p, 0);
		}

531
		set_page_refcounted(page);
N
Nick Piggin 已提交
532
		__free_pages(page, order);
533 534 535
	}
}

L
Linus Torvalds 已提交
536 537 538 539 540 541 542 543 544 545 546 547 548 549 550

/*
 * 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
551
static inline void expand(struct zone *zone, struct page *page,
L
Linus Torvalds 已提交
552 553 554 555 556 557 558 559
 	int low, int high, struct free_area *area)
{
	unsigned long size = 1 << high;

	while (high > low) {
		area--;
		high--;
		size >>= 1;
N
Nick Piggin 已提交
560
		VM_BUG_ON(bad_range(zone, &page[size]));
L
Linus Torvalds 已提交
561 562 563 564 565 566 567 568 569
		list_add(&page[size].lru, &area->free_list);
		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
570
static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
L
Linus Torvalds 已提交
571
{
N
Nick Piggin 已提交
572 573 574
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
		(page_count(page) != 0)  |
575 576
		(page->flags & (
			1 << PG_lru	|
L
Linus Torvalds 已提交
577 578 579 580 581
			1 << PG_private	|
			1 << PG_locked	|
			1 << PG_active	|
			1 << PG_dirty	|
			1 << PG_reclaim	|
582
			1 << PG_slab    |
L
Linus Torvalds 已提交
583
			1 << PG_swapcache |
N
Nick Piggin 已提交
584
			1 << PG_writeback |
585 586
			1 << PG_reserved |
			1 << PG_buddy ))))
N
Nick Piggin 已提交
587
		bad_page(page);
L
Linus Torvalds 已提交
588

589 590 591 592 593 594 595
	/*
	 * For now, we report if PG_reserved was found set, but do not
	 * clear it, and do not allocate the page: as a safety net.
	 */
	if (PageReserved(page))
		return 1;

L
Linus Torvalds 已提交
596 597 598
	page->flags &= ~(1 << PG_uptodate | 1 << PG_error |
			1 << PG_referenced | 1 << PG_arch_1 |
			1 << PG_checked | 1 << PG_mappedtodisk);
H
Hugh Dickins 已提交
599
	set_page_private(page, 0);
600
	set_page_refcounted(page);
N
Nick Piggin 已提交
601 602

	arch_alloc_page(page, order);
L
Linus Torvalds 已提交
603
	kernel_map_pages(page, 1 << order, 1);
N
Nick Piggin 已提交
604 605 606 607 608 609 610

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

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

611
	return 0;
L
Linus Torvalds 已提交
612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633
}

/* 
 * Do the hard work of removing an element from the buddy allocator.
 * Call me with the zone->lock already held.
 */
static struct page *__rmqueue(struct zone *zone, unsigned int order)
{
	struct free_area * area;
	unsigned int current_order;
	struct page *page;

	for (current_order = order; current_order < MAX_ORDER; ++current_order) {
		area = zone->free_area + current_order;
		if (list_empty(&area->free_list))
			continue;

		page = list_entry(area->free_list.next, struct page, lru);
		list_del(&page->lru);
		rmv_page_order(page);
		area->nr_free--;
		zone->free_pages -= 1UL << order;
N
Nick Piggin 已提交
634 635
		expand(zone, page, order, current_order, area);
		return page;
L
Linus Torvalds 已提交
636 637 638 639 640 641 642 643 644 645 646 647 648 649 650
	}

	return NULL;
}

/* 
 * 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, 
			unsigned long count, struct list_head *list)
{
	int i;
	
N
Nick Piggin 已提交
651
	spin_lock(&zone->lock);
L
Linus Torvalds 已提交
652
	for (i = 0; i < count; ++i) {
N
Nick Piggin 已提交
653 654
		struct page *page = __rmqueue(zone, order);
		if (unlikely(page == NULL))
L
Linus Torvalds 已提交
655 656 657
			break;
		list_add_tail(&page->lru, list);
	}
N
Nick Piggin 已提交
658
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
659
	return i;
L
Linus Torvalds 已提交
660 661
}

662
#ifdef CONFIG_NUMA
663 664
/*
 * Called from the slab reaper to drain pagesets on a particular node that
665
 * belongs to the currently executing processor.
666 667
 * Note that this function must be called with the thread pinned to
 * a single processor.
668 669
 */
void drain_node_pages(int nodeid)
670
{
671 672
	int i;
	enum zone_type z;
673 674
	unsigned long flags;

675 676
	for (z = 0; z < MAX_NR_ZONES; z++) {
		struct zone *zone = NODE_DATA(nodeid)->node_zones + z;
677 678
		struct per_cpu_pageset *pset;

679 680 681
		if (!populated_zone(zone))
			continue;

N
Nick Piggin 已提交
682
		pset = zone_pcp(zone, smp_processor_id());
683 684 685 686
		for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) {
			struct per_cpu_pages *pcp;

			pcp = &pset->pcp[i];
687
			if (pcp->count) {
688 689
				int to_drain;

690
				local_irq_save(flags);
691 692 693 694 695 696
				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;
697 698
				local_irq_restore(flags);
			}
699 700 701 702 703
		}
	}
}
#endif

L
Linus Torvalds 已提交
704 705 706
#if defined(CONFIG_PM) || defined(CONFIG_HOTPLUG_CPU)
static void __drain_pages(unsigned int cpu)
{
N
Nick Piggin 已提交
707
	unsigned long flags;
L
Linus Torvalds 已提交
708 709 710 711 712 713
	struct zone *zone;
	int i;

	for_each_zone(zone) {
		struct per_cpu_pageset *pset;

714
		pset = zone_pcp(zone, cpu);
L
Linus Torvalds 已提交
715 716 717 718
		for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) {
			struct per_cpu_pages *pcp;

			pcp = &pset->pcp[i];
N
Nick Piggin 已提交
719
			local_irq_save(flags);
N
Nick Piggin 已提交
720 721
			free_pages_bulk(zone, pcp->count, &pcp->list, 0);
			pcp->count = 0;
N
Nick Piggin 已提交
722
			local_irq_restore(flags);
L
Linus Torvalds 已提交
723 724 725 726 727 728 729 730 731
		}
	}
}
#endif /* CONFIG_PM || CONFIG_HOTPLUG_CPU */

#ifdef CONFIG_PM

void mark_free_pages(struct zone *zone)
{
732 733
	unsigned long pfn, max_zone_pfn;
	unsigned long flags;
L
Linus Torvalds 已提交
734 735 736 737 738 739 740
	int order;
	struct list_head *curr;

	if (!zone->spanned_pages)
		return;

	spin_lock_irqsave(&zone->lock, flags);
741 742 743 744 745 746 747 748 749

	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);

			if (!PageNosave(page))
				ClearPageNosaveFree(page);
		}
L
Linus Torvalds 已提交
750 751 752

	for (order = MAX_ORDER - 1; order >= 0; --order)
		list_for_each(curr, &zone->free_area[order].free_list) {
753
			unsigned long i;
L
Linus Torvalds 已提交
754

755 756 757 758
			pfn = page_to_pfn(list_entry(curr, struct page, lru));
			for (i = 0; i < (1UL << order); i++)
				SetPageNosaveFree(pfn_to_page(pfn + i));
		}
L
Linus Torvalds 已提交
759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786

	spin_unlock_irqrestore(&zone->lock, flags);
}

/*
 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
 */
void drain_local_pages(void)
{
	unsigned long flags;

	local_irq_save(flags);	
	__drain_pages(smp_processor_id());
	local_irq_restore(flags);	
}
#endif /* CONFIG_PM */

/*
 * Free a 0-order page
 */
static void fastcall free_hot_cold_page(struct page *page, int cold)
{
	struct zone *zone = page_zone(page);
	struct per_cpu_pages *pcp;
	unsigned long flags;

	if (PageAnon(page))
		page->mapping = NULL;
N
Nick Piggin 已提交
787
	if (free_pages_check(page))
788 789
		return;

N
Nick Piggin 已提交
790 791
	if (!PageHighMem(page))
		debug_check_no_locks_freed(page_address(page), PAGE_SIZE);
N
Nick Piggin 已提交
792
	arch_free_page(page, 0);
793 794
	kernel_map_pages(page, 1, 0);

795
	pcp = &zone_pcp(zone, get_cpu())->pcp[cold];
L
Linus Torvalds 已提交
796
	local_irq_save(flags);
797
	__count_vm_event(PGFREE);
L
Linus Torvalds 已提交
798 799
	list_add(&page->lru, &pcp->list);
	pcp->count++;
N
Nick Piggin 已提交
800 801 802 803
	if (pcp->count >= pcp->high) {
		free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
		pcp->count -= pcp->batch;
	}
L
Linus Torvalds 已提交
804 805 806 807 808 809 810 811 812 813 814 815 816 817
	local_irq_restore(flags);
	put_cpu();
}

void fastcall free_hot_page(struct page *page)
{
	free_hot_cold_page(page, 0);
}
	
void fastcall free_cold_page(struct page *page)
{
	free_hot_cold_page(page, 1);
}

N
Nick Piggin 已提交
818 819 820 821 822 823 824 825 826 827 828 829
/*
 * 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
830 831
	VM_BUG_ON(PageCompound(page));
	VM_BUG_ON(!page_count(page));
832 833
	for (i = 1; i < (1 << order); i++)
		set_page_refcounted(page + i);
N
Nick Piggin 已提交
834 835
}

L
Linus Torvalds 已提交
836 837 838 839 840
/*
 * 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.
 */
N
Nick Piggin 已提交
841 842
static struct page *buffered_rmqueue(struct zonelist *zonelist,
			struct zone *zone, int order, gfp_t gfp_flags)
L
Linus Torvalds 已提交
843 844
{
	unsigned long flags;
845
	struct page *page;
L
Linus Torvalds 已提交
846
	int cold = !!(gfp_flags & __GFP_COLD);
N
Nick Piggin 已提交
847
	int cpu;
L
Linus Torvalds 已提交
848

849
again:
N
Nick Piggin 已提交
850
	cpu  = get_cpu();
N
Nick Piggin 已提交
851
	if (likely(order == 0)) {
L
Linus Torvalds 已提交
852 853
		struct per_cpu_pages *pcp;

N
Nick Piggin 已提交
854
		pcp = &zone_pcp(zone, cpu)->pcp[cold];
L
Linus Torvalds 已提交
855
		local_irq_save(flags);
N
Nick Piggin 已提交
856
		if (!pcp->count) {
857
			pcp->count = rmqueue_bulk(zone, 0,
L
Linus Torvalds 已提交
858
						pcp->batch, &pcp->list);
N
Nick Piggin 已提交
859 860
			if (unlikely(!pcp->count))
				goto failed;
L
Linus Torvalds 已提交
861
		}
N
Nick Piggin 已提交
862 863 864
		page = list_entry(pcp->list.next, struct page, lru);
		list_del(&page->lru);
		pcp->count--;
R
Rohit Seth 已提交
865
	} else {
L
Linus Torvalds 已提交
866 867
		spin_lock_irqsave(&zone->lock, flags);
		page = __rmqueue(zone, order);
N
Nick Piggin 已提交
868 869 870
		spin_unlock(&zone->lock);
		if (!page)
			goto failed;
L
Linus Torvalds 已提交
871 872
	}

873
	__count_zone_vm_events(PGALLOC, zone, 1 << order);
874
	zone_statistics(zonelist, zone);
N
Nick Piggin 已提交
875 876
	local_irq_restore(flags);
	put_cpu();
L
Linus Torvalds 已提交
877

N
Nick Piggin 已提交
878
	VM_BUG_ON(bad_range(zone, page));
N
Nick Piggin 已提交
879
	if (prep_new_page(page, order, gfp_flags))
N
Nick Piggin 已提交
880
		goto again;
L
Linus Torvalds 已提交
881
	return page;
N
Nick Piggin 已提交
882 883 884 885 886

failed:
	local_irq_restore(flags);
	put_cpu();
	return NULL;
L
Linus Torvalds 已提交
887 888
}

R
Rohit Seth 已提交
889
#define ALLOC_NO_WATERMARKS	0x01 /* don't check watermarks at all */
890 891 892 893 894 895
#define ALLOC_WMARK_MIN		0x02 /* use pages_min watermark */
#define ALLOC_WMARK_LOW		0x04 /* use pages_low watermark */
#define ALLOC_WMARK_HIGH	0x08 /* use pages_high watermark */
#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
896

L
Linus Torvalds 已提交
897 898 899 900 901
/*
 * 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
902
		      int classzone_idx, int alloc_flags)
L
Linus Torvalds 已提交
903 904
{
	/* free_pages my go negative - that's OK */
905 906
	unsigned long min = mark;
	long free_pages = z->free_pages - (1 << order) + 1;
L
Linus Torvalds 已提交
907 908
	int o;

R
Rohit Seth 已提交
909
	if (alloc_flags & ALLOC_HIGH)
L
Linus Torvalds 已提交
910
		min -= min / 2;
R
Rohit Seth 已提交
911
	if (alloc_flags & ALLOC_HARDER)
L
Linus Torvalds 已提交
912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928
		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;
}

929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048
#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
 * that have to skip over alot of full or unallowed zones.
 *
 * If the zonelist cache is present in the passed in zonelist, then
 * returns a pointer to the allowed node mask (either the current
 * tasks mems_allowed, or node_online_map.)
 *
 * 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;

	if (jiffies - zlc->last_full_zap > 1 * HZ) {
		bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
		zlc->last_full_zap = jiffies;
	}

	allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
					&cpuset_current_mems_allowed :
					&node_online_map;
	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.
 */
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zone **z,
						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;

	i = z - zonelist->zones;
	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.
 */
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zone **z)
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	int i;				/* index of *z in zonelist zones */

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

	i = z - zonelist->zones;

	set_bit(i, zlc->fullzones);
}

#else	/* CONFIG_NUMA */

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

static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zone **z,
				nodemask_t *allowednodes)
{
	return 1;
}

static void zlc_mark_zone_full(struct zonelist *zonelist, struct zone **z)
{
}
#endif	/* CONFIG_NUMA */

R
Rohit Seth 已提交
1049
/*
1050
 * get_page_from_freelist goes through the zonelist trying to allocate
R
Rohit Seth 已提交
1051 1052 1053 1054 1055
 * a page.
 */
static struct page *
get_page_from_freelist(gfp_t gfp_mask, unsigned int order,
		struct zonelist *zonelist, int alloc_flags)
M
Martin Hicks 已提交
1056
{
1057
	struct zone **z;
R
Rohit Seth 已提交
1058
	struct page *page = NULL;
1059
	int classzone_idx = zone_idx(zonelist->zones[0]);
1060
	struct zone *zone;
1061 1062 1063
	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 */
R
Rohit Seth 已提交
1064

1065
zonelist_scan:
R
Rohit Seth 已提交
1066
	/*
1067
	 * Scan zonelist, looking for a zone with enough free.
R
Rohit Seth 已提交
1068 1069
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
	 */
1070 1071
	z = zonelist->zones;

R
Rohit Seth 已提交
1072
	do {
1073 1074 1075
		if (NUMA_BUILD && zlc_active &&
			!zlc_zone_worth_trying(zonelist, z, allowednodes))
				continue;
1076
		zone = *z;
1077
		if (unlikely(NUMA_BUILD && (gfp_mask & __GFP_THISNODE) &&
1078
			zone->zone_pgdat != zonelist->zones[0]->zone_pgdat))
1079
				break;
R
Rohit Seth 已提交
1080
		if ((alloc_flags & ALLOC_CPUSET) &&
1081
			!cpuset_zone_allowed(zone, gfp_mask))
1082
				goto try_next_zone;
R
Rohit Seth 已提交
1083 1084

		if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1085 1086
			unsigned long mark;
			if (alloc_flags & ALLOC_WMARK_MIN)
1087
				mark = zone->pages_min;
1088
			else if (alloc_flags & ALLOC_WMARK_LOW)
1089
				mark = zone->pages_low;
1090
			else
1091
				mark = zone->pages_high;
1092 1093
			if (!zone_watermark_ok(zone, order, mark,
				    classzone_idx, alloc_flags)) {
1094
				if (!zone_reclaim_mode ||
1095
				    !zone_reclaim(zone, gfp_mask, order))
1096
					goto this_zone_full;
1097
			}
R
Rohit Seth 已提交
1098 1099
		}

1100
		page = buffered_rmqueue(zonelist, zone, order, gfp_mask);
1101
		if (page)
R
Rohit Seth 已提交
1102
			break;
1103 1104 1105 1106 1107 1108 1109 1110 1111 1112
this_zone_full:
		if (NUMA_BUILD)
			zlc_mark_zone_full(zonelist, z);
try_next_zone:
		if (NUMA_BUILD && !did_zlc_setup) {
			/* we do zlc_setup after the first zone is tried */
			allowednodes = zlc_setup(zonelist, alloc_flags);
			zlc_active = 1;
			did_zlc_setup = 1;
		}
R
Rohit Seth 已提交
1113
	} while (*(++z) != NULL);
1114 1115 1116 1117 1118 1119

	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
1120
	return page;
M
Martin Hicks 已提交
1121 1122
}

L
Linus Torvalds 已提交
1123 1124 1125 1126
/*
 * This is the 'heart' of the zoned buddy allocator.
 */
struct page * fastcall
A
Al Viro 已提交
1127
__alloc_pages(gfp_t gfp_mask, unsigned int order,
L
Linus Torvalds 已提交
1128 1129
		struct zonelist *zonelist)
{
A
Al Viro 已提交
1130
	const gfp_t wait = gfp_mask & __GFP_WAIT;
R
Rohit Seth 已提交
1131
	struct zone **z;
L
Linus Torvalds 已提交
1132 1133 1134 1135
	struct page *page;
	struct reclaim_state reclaim_state;
	struct task_struct *p = current;
	int do_retry;
R
Rohit Seth 已提交
1136
	int alloc_flags;
L
Linus Torvalds 已提交
1137 1138 1139 1140
	int did_some_progress;

	might_sleep_if(wait);

1141
restart:
R
Rohit Seth 已提交
1142
	z = zonelist->zones;  /* the list of zones suitable for gfp_mask */
L
Linus Torvalds 已提交
1143

R
Rohit Seth 已提交
1144
	if (unlikely(*z == NULL)) {
L
Linus Torvalds 已提交
1145 1146 1147
		/* Should this ever happen?? */
		return NULL;
	}
1148

R
Rohit Seth 已提交
1149
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order,
1150
				zonelist, ALLOC_WMARK_LOW|ALLOC_CPUSET);
R
Rohit Seth 已提交
1151 1152
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1153

1154
	for (z = zonelist->zones; *z; z++)
1155
		wakeup_kswapd(*z, order);
L
Linus Torvalds 已提交
1156

1157
	/*
R
Rohit Seth 已提交
1158 1159 1160 1161 1162 1163
	 * 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.
	 *
	 * The caller may dip into page reserves a bit more if the caller
	 * cannot run direct reclaim, or if the caller has realtime scheduling
P
Paul Jackson 已提交
1164 1165
	 * policy or is asking for __GFP_HIGH memory.  GFP_ATOMIC requests will
	 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1166
	 */
1167
	alloc_flags = ALLOC_WMARK_MIN;
R
Rohit Seth 已提交
1168 1169 1170 1171
	if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait)
		alloc_flags |= ALLOC_HARDER;
	if (gfp_mask & __GFP_HIGH)
		alloc_flags |= ALLOC_HIGH;
1172 1173
	if (wait)
		alloc_flags |= ALLOC_CPUSET;
L
Linus Torvalds 已提交
1174 1175 1176

	/*
	 * Go through the zonelist again. Let __GFP_HIGH and allocations
R
Rohit Seth 已提交
1177
	 * coming from realtime tasks go deeper into reserves.
L
Linus Torvalds 已提交
1178 1179 1180
	 *
	 * This is the last chance, in general, before the goto nopage.
	 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1181
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
L
Linus Torvalds 已提交
1182
	 */
R
Rohit Seth 已提交
1183 1184 1185
	page = get_page_from_freelist(gfp_mask, order, zonelist, alloc_flags);
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1186 1187

	/* This allocation should allow future memory freeing. */
1188

1189
rebalance:
1190 1191 1192
	if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE)))
			&& !in_interrupt()) {
		if (!(gfp_mask & __GFP_NOMEMALLOC)) {
K
Kirill Korotaev 已提交
1193
nofail_alloc:
1194
			/* go through the zonelist yet again, ignoring mins */
R
Rohit Seth 已提交
1195
			page = get_page_from_freelist(gfp_mask, order,
1196
				zonelist, ALLOC_NO_WATERMARKS);
R
Rohit Seth 已提交
1197 1198
			if (page)
				goto got_pg;
K
Kirill Korotaev 已提交
1199
			if (gfp_mask & __GFP_NOFAIL) {
1200
				congestion_wait(WRITE, HZ/50);
K
Kirill Korotaev 已提交
1201 1202
				goto nofail_alloc;
			}
L
Linus Torvalds 已提交
1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213
		}
		goto nopage;
	}

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

	cond_resched();

	/* We now go into synchronous reclaim */
1214
	cpuset_memory_pressure_bump();
L
Linus Torvalds 已提交
1215 1216 1217 1218
	p->flags |= PF_MEMALLOC;
	reclaim_state.reclaimed_slab = 0;
	p->reclaim_state = &reclaim_state;

R
Rohit Seth 已提交
1219
	did_some_progress = try_to_free_pages(zonelist->zones, gfp_mask);
L
Linus Torvalds 已提交
1220 1221 1222 1223 1224 1225 1226

	p->reclaim_state = NULL;
	p->flags &= ~PF_MEMALLOC;

	cond_resched();

	if (likely(did_some_progress)) {
R
Rohit Seth 已提交
1227 1228 1229 1230
		page = get_page_from_freelist(gfp_mask, order,
						zonelist, alloc_flags);
		if (page)
			goto got_pg;
L
Linus Torvalds 已提交
1231 1232 1233 1234 1235 1236 1237
	} else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
		/*
		 * 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.
		 */
R
Rohit Seth 已提交
1238
		page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order,
1239
				zonelist, ALLOC_WMARK_HIGH|ALLOC_CPUSET);
R
Rohit Seth 已提交
1240 1241
		if (page)
			goto got_pg;
L
Linus Torvalds 已提交
1242

1243
		out_of_memory(zonelist, gfp_mask, order);
L
Linus Torvalds 已提交
1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261
		goto restart;
	}

	/*
	 * Don't let big-order allocations loop unless the caller explicitly
	 * requests that.  Wait for some write requests to complete then retry.
	 *
	 * In this implementation, __GFP_REPEAT means __GFP_NOFAIL for order
	 * <= 3, but that may not be true in other implementations.
	 */
	do_retry = 0;
	if (!(gfp_mask & __GFP_NORETRY)) {
		if ((order <= 3) || (gfp_mask & __GFP_REPEAT))
			do_retry = 1;
		if (gfp_mask & __GFP_NOFAIL)
			do_retry = 1;
	}
	if (do_retry) {
1262
		congestion_wait(WRITE, HZ/50);
L
Linus Torvalds 已提交
1263 1264 1265 1266 1267 1268 1269 1270 1271
		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
1272
		show_mem();
L
Linus Torvalds 已提交
1273 1274 1275 1276 1277 1278 1279 1280 1281 1282
	}
got_pg:
	return page;
}

EXPORT_SYMBOL(__alloc_pages);

/*
 * Common helper functions.
 */
A
Al Viro 已提交
1283
fastcall unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
L
Linus Torvalds 已提交
1284 1285 1286 1287 1288 1289 1290 1291 1292 1293
{
	struct page * page;
	page = alloc_pages(gfp_mask, order);
	if (!page)
		return 0;
	return (unsigned long) page_address(page);
}

EXPORT_SYMBOL(__get_free_pages);

A
Al Viro 已提交
1294
fastcall unsigned long get_zeroed_page(gfp_t gfp_mask)
L
Linus Torvalds 已提交
1295 1296 1297 1298 1299 1300 1301
{
	struct page * page;

	/*
	 * get_zeroed_page() returns a 32-bit address, which cannot represent
	 * a highmem page
	 */
N
Nick Piggin 已提交
1302
	VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
L
Linus Torvalds 已提交
1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321

	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);
}

fastcall void __free_pages(struct page *page, unsigned int order)
{
N
Nick Piggin 已提交
1322
	if (put_page_testzero(page)) {
L
Linus Torvalds 已提交
1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334
		if (order == 0)
			free_hot_page(page);
		else
			__free_pages_ok(page, order);
	}
}

EXPORT_SYMBOL(__free_pages);

fastcall void free_pages(unsigned long addr, unsigned int order)
{
	if (addr != 0) {
N
Nick Piggin 已提交
1335
		VM_BUG_ON(!virt_addr_valid((void *)addr));
L
Linus Torvalds 已提交
1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360
		__free_pages(virt_to_page((void *)addr), order);
	}
}

EXPORT_SYMBOL(free_pages);

/*
 * Total amount of free (allocatable) RAM:
 */
unsigned int nr_free_pages(void)
{
	unsigned int sum = 0;
	struct zone *zone;

	for_each_zone(zone)
		sum += zone->free_pages;

	return sum;
}

EXPORT_SYMBOL(nr_free_pages);

#ifdef CONFIG_NUMA
unsigned int nr_free_pages_pgdat(pg_data_t *pgdat)
{
1361 1362
	unsigned int sum = 0;
	enum zone_type i;
L
Linus Torvalds 已提交
1363 1364 1365 1366 1367 1368 1369 1370 1371 1372

	for (i = 0; i < MAX_NR_ZONES; i++)
		sum += pgdat->node_zones[i].free_pages;

	return sum;
}
#endif

static unsigned int nr_free_zone_pages(int offset)
{
1373 1374
	/* Just pick one node, since fallback list is circular */
	pg_data_t *pgdat = NODE_DATA(numa_node_id());
L
Linus Torvalds 已提交
1375 1376
	unsigned int sum = 0;

1377 1378 1379
	struct zonelist *zonelist = pgdat->node_zonelists + offset;
	struct zone **zonep = zonelist->zones;
	struct zone *zone;
L
Linus Torvalds 已提交
1380

1381 1382 1383 1384 1385
	for (zone = *zonep++; zone; zone = *zonep++) {
		unsigned long size = zone->present_pages;
		unsigned long high = zone->pages_high;
		if (size > high)
			sum += size - high;
L
Linus Torvalds 已提交
1386 1387 1388 1389 1390 1391 1392 1393 1394 1395
	}

	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
1396
	return nr_free_zone_pages(gfp_zone(GFP_USER));
L
Linus Torvalds 已提交
1397 1398 1399 1400 1401 1402 1403
}

/*
 * Amount of free RAM allocatable within all zones
 */
unsigned int nr_free_pagecache_pages(void)
{
A
Al Viro 已提交
1404
	return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER));
L
Linus Torvalds 已提交
1405
}
1406 1407

static inline void show_node(struct zone *zone)
L
Linus Torvalds 已提交
1408
{
1409
	if (NUMA_BUILD)
1410
		printk("Node %d ", zone_to_nid(zone));
L
Linus Torvalds 已提交
1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432
}

void si_meminfo(struct sysinfo *val)
{
	val->totalram = totalram_pages;
	val->sharedram = 0;
	val->freeram = nr_free_pages();
	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;
	val->freeram = nr_free_pages_pgdat(pgdat);
1433
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
1434 1435
	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
	val->freehigh = pgdat->node_zones[ZONE_HIGHMEM].free_pages;
1436 1437 1438 1439
#else
	val->totalhigh = 0;
	val->freehigh = 0;
#endif
L
Linus Torvalds 已提交
1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452
	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)
{
1453
	int cpu;
L
Linus Torvalds 已提交
1454 1455 1456 1457 1458 1459
	unsigned long active;
	unsigned long inactive;
	unsigned long free;
	struct zone *zone;

	for_each_zone(zone) {
1460
		if (!populated_zone(zone))
L
Linus Torvalds 已提交
1461
			continue;
1462 1463 1464

		show_node(zone);
		printk("%s per-cpu:\n", zone->name);
L
Linus Torvalds 已提交
1465

1466
		for_each_online_cpu(cpu) {
L
Linus Torvalds 已提交
1467 1468
			struct per_cpu_pageset *pageset;

1469
			pageset = zone_pcp(zone, cpu);
L
Linus Torvalds 已提交
1470

1471 1472 1473 1474 1475 1476
			printk("CPU %4d: Hot: hi:%5d, btch:%4d usd:%4d   "
			       "Cold: hi:%5d, btch:%4d usd:%4d\n",
			       cpu, pageset->pcp[0].high,
			       pageset->pcp[0].batch, pageset->pcp[0].count,
			       pageset->pcp[1].high, pageset->pcp[1].batch,
			       pageset->pcp[1].count);
L
Linus Torvalds 已提交
1477 1478 1479 1480 1481 1482 1483 1484 1485
		}
	}

	get_zone_counts(&active, &inactive, &free);

	printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu "
		"unstable:%lu free:%u slab:%lu mapped:%lu pagetables:%lu\n",
		active,
		inactive,
1486
		global_page_state(NR_FILE_DIRTY),
1487
		global_page_state(NR_WRITEBACK),
1488
		global_page_state(NR_UNSTABLE_NFS),
L
Linus Torvalds 已提交
1489
		nr_free_pages(),
1490 1491
		global_page_state(NR_SLAB_RECLAIMABLE) +
			global_page_state(NR_SLAB_UNRECLAIMABLE),
1492
		global_page_state(NR_FILE_MAPPED),
1493
		global_page_state(NR_PAGETABLE));
L
Linus Torvalds 已提交
1494 1495 1496 1497

	for_each_zone(zone) {
		int i;

1498 1499 1500
		if (!populated_zone(zone))
			continue;

L
Linus Torvalds 已提交
1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530
		show_node(zone);
		printk("%s"
			" free:%lukB"
			" min:%lukB"
			" low:%lukB"
			" high:%lukB"
			" active:%lukB"
			" inactive:%lukB"
			" present:%lukB"
			" pages_scanned:%lu"
			" all_unreclaimable? %s"
			"\n",
			zone->name,
			K(zone->free_pages),
			K(zone->pages_min),
			K(zone->pages_low),
			K(zone->pages_high),
			K(zone->nr_active),
			K(zone->nr_inactive),
			K(zone->present_pages),
			zone->pages_scanned,
			(zone->all_unreclaimable ? "yes" : "no")
			);
		printk("lowmem_reserve[]:");
		for (i = 0; i < MAX_NR_ZONES; i++)
			printk(" %lu", zone->lowmem_reserve[i]);
		printk("\n");
	}

	for_each_zone(zone) {
1531
 		unsigned long nr[MAX_ORDER], flags, order, total = 0;
L
Linus Torvalds 已提交
1532

1533 1534 1535
		if (!populated_zone(zone))
			continue;

L
Linus Torvalds 已提交
1536 1537 1538 1539 1540
		show_node(zone);
		printk("%s: ", zone->name);

		spin_lock_irqsave(&zone->lock, flags);
		for (order = 0; order < MAX_ORDER; order++) {
1541 1542
			nr[order] = zone->free_area[order].nr_free;
			total += nr[order] << order;
L
Linus Torvalds 已提交
1543 1544
		}
		spin_unlock_irqrestore(&zone->lock, flags);
1545 1546
		for (order = 0; order < MAX_ORDER; order++)
			printk("%lu*%lukB ", nr[order], K(1UL) << order);
L
Linus Torvalds 已提交
1547 1548 1549 1550 1551 1552 1553 1554
		printk("= %lukB\n", K(total));
	}

	show_swap_cache_info();
}

/*
 * Builds allocation fallback zone lists.
1555 1556
 *
 * Add all populated zones of a node to the zonelist.
L
Linus Torvalds 已提交
1557
 */
1558
static int __meminit build_zonelists_node(pg_data_t *pgdat,
1559
			struct zonelist *zonelist, int nr_zones, enum zone_type zone_type)
L
Linus Torvalds 已提交
1560
{
1561 1562
	struct zone *zone;

1563
	BUG_ON(zone_type >= MAX_NR_ZONES);
1564
	zone_type++;
1565 1566

	do {
1567
		zone_type--;
1568
		zone = pgdat->node_zones + zone_type;
1569
		if (populated_zone(zone)) {
1570 1571
			zonelist->zones[nr_zones++] = zone;
			check_highest_zone(zone_type);
L
Linus Torvalds 已提交
1572
		}
1573

1574
	} while (zone_type);
1575
	return nr_zones;
L
Linus Torvalds 已提交
1576 1577 1578 1579
}

#ifdef CONFIG_NUMA
#define MAX_NODE_LOAD (num_online_nodes())
1580
static int __meminitdata node_load[MAX_NUMNODES];
L
Linus Torvalds 已提交
1581
/**
1582
 * find_next_best_node - find the next node that should appear in a given node's fallback list
L
Linus Torvalds 已提交
1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594
 * @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.
 */
1595
static int __meminit find_next_best_node(int node, nodemask_t *used_node_mask)
L
Linus Torvalds 已提交
1596
{
1597
	int n, val;
L
Linus Torvalds 已提交
1598 1599 1600
	int min_val = INT_MAX;
	int best_node = -1;

1601 1602 1603 1604 1605
	/* 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
1606

1607 1608
	for_each_online_node(n) {
		cpumask_t tmp;
L
Linus Torvalds 已提交
1609 1610 1611 1612 1613 1614 1615 1616

		/* 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);

1617 1618 1619
		/* Penalize nodes under us ("prefer the next node") */
		val += (n < node);

L
Linus Torvalds 已提交
1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640
		/* Give preference to headless and unused nodes */
		tmp = node_to_cpumask(n);
		if (!cpus_empty(tmp))
			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;
}

1641
static void __meminit build_zonelists(pg_data_t *pgdat)
L
Linus Torvalds 已提交
1642
{
1643 1644
	int j, node, local_node;
	enum zone_type i;
L
Linus Torvalds 已提交
1645 1646 1647 1648 1649
	int prev_node, load;
	struct zonelist *zonelist;
	nodemask_t used_mask;

	/* initialize zonelists */
1650
	for (i = 0; i < MAX_NR_ZONES; i++) {
L
Linus Torvalds 已提交
1651 1652 1653 1654 1655 1656 1657 1658 1659 1660
		zonelist = pgdat->node_zonelists + i;
		zonelist->zones[0] = NULL;
	}

	/* NUMA-aware ordering of nodes */
	local_node = pgdat->node_id;
	load = num_online_nodes();
	prev_node = local_node;
	nodes_clear(used_mask);
	while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
1661 1662 1663 1664 1665 1666 1667 1668 1669
		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
1670 1671 1672 1673 1674
		/*
		 * 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.
		 */
1675 1676

		if (distance != node_distance(local_node, prev_node))
L
Linus Torvalds 已提交
1677 1678 1679
			node_load[node] += load;
		prev_node = node;
		load--;
1680
		for (i = 0; i < MAX_NR_ZONES; i++) {
L
Linus Torvalds 已提交
1681 1682 1683
			zonelist = pgdat->node_zonelists + i;
			for (j = 0; zonelist->zones[j] != NULL; j++);

1684
	 		j = build_zonelists_node(NODE_DATA(node), zonelist, j, i);
L
Linus Torvalds 已提交
1685 1686 1687 1688 1689
			zonelist->zones[j] = NULL;
		}
	}
}

1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707
/* Construct the zonelist performance cache - see further mmzone.h */
static void __meminit build_zonelist_cache(pg_data_t *pgdat)
{
	int i;

	for (i = 0; i < MAX_NR_ZONES; i++) {
		struct zonelist *zonelist;
		struct zonelist_cache *zlc;
		struct zone **z;

		zonelist = pgdat->node_zonelists + i;
		zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
		bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
		for (z = zonelist->zones; *z; z++)
			zlc->z_to_n[z - zonelist->zones] = zone_to_nid(*z);
	}
}

L
Linus Torvalds 已提交
1708 1709
#else	/* CONFIG_NUMA */

1710
static void __meminit build_zonelists(pg_data_t *pgdat)
L
Linus Torvalds 已提交
1711
{
1712 1713
	int node, local_node;
	enum zone_type i,j;
L
Linus Torvalds 已提交
1714 1715

	local_node = pgdat->node_id;
1716
	for (i = 0; i < MAX_NR_ZONES; i++) {
L
Linus Torvalds 已提交
1717 1718 1719 1720
		struct zonelist *zonelist;

		zonelist = pgdat->node_zonelists + i;

1721
 		j = build_zonelists_node(pgdat, zonelist, 0, i);
L
Linus Torvalds 已提交
1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732
 		/*
 		 * 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;
1733
			j = build_zonelists_node(NODE_DATA(node), zonelist, j, i);
L
Linus Torvalds 已提交
1734 1735 1736 1737
		}
		for (node = 0; node < local_node; node++) {
			if (!node_online(node))
				continue;
1738
			j = build_zonelists_node(NODE_DATA(node), zonelist, j, i);
L
Linus Torvalds 已提交
1739 1740 1741 1742 1743 1744
		}

		zonelist->zones[j] = NULL;
	}
}

1745 1746 1747 1748 1749 1750 1751 1752 1753
/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
static void __meminit build_zonelist_cache(pg_data_t *pgdat)
{
	int i;

	for (i = 0; i < MAX_NR_ZONES; i++)
		pgdat->node_zonelists[i].zlcache_ptr = NULL;
}

L
Linus Torvalds 已提交
1754 1755
#endif	/* CONFIG_NUMA */

1756 1757
/* return values int ....just for stop_machine_run() */
static int __meminit __build_all_zonelists(void *dummy)
L
Linus Torvalds 已提交
1758
{
1759
	int nid;
1760 1761

	for_each_online_node(nid) {
1762
		build_zonelists(NODE_DATA(nid));
1763 1764
		build_zonelist_cache(NODE_DATA(nid));
	}
1765 1766 1767 1768 1769 1770
	return 0;
}

void __meminit build_all_zonelists(void)
{
	if (system_state == SYSTEM_BOOTING) {
1771
		__build_all_zonelists(NULL);
1772 1773 1774 1775 1776 1777 1778
		cpuset_init_current_mems_allowed();
	} else {
		/* we have to stop all cpus to guaranntee there is no user
		   of zonelist */
		stop_machine_run(__build_all_zonelists, NULL, NR_CPUS);
		/* cpuset refresh routine should be here */
	}
1779 1780 1781
	vm_total_pages = nr_free_pagecache_pages();
	printk("Built %i zonelists.  Total pages: %ld\n",
			num_online_nodes(), vm_total_pages);
L
Linus Torvalds 已提交
1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796
}

/*
 * 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

1797
#ifndef CONFIG_MEMORY_HOTPLUG
1798
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
L
Linus Torvalds 已提交
1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815
{
	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);
}
1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838
#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
1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856

/*
 * 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))

/*
 * 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.
 */
1857
void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
L
Linus Torvalds 已提交
1858 1859 1860
		unsigned long start_pfn)
{
	struct page *page;
A
Andy Whitcroft 已提交
1861 1862
	unsigned long end_pfn = start_pfn + size;
	unsigned long pfn;
L
Linus Torvalds 已提交
1863

1864
	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
A
Andy Whitcroft 已提交
1865 1866
		if (!early_pfn_valid(pfn))
			continue;
1867 1868
		if (!early_pfn_in_nid(pfn, nid))
			continue;
A
Andy Whitcroft 已提交
1869 1870
		page = pfn_to_page(pfn);
		set_page_links(page, zone, nid, pfn);
1871
		init_page_count(page);
L
Linus Torvalds 已提交
1872 1873 1874 1875 1876 1877
		reset_page_mapcount(page);
		SetPageReserved(page);
		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))
1878
			set_page_address(page, __va(pfn << PAGE_SHIFT));
L
Linus Torvalds 已提交
1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897
#endif
	}
}

void zone_init_free_lists(struct pglist_data *pgdat, struct zone *zone,
				unsigned long size)
{
	int order;
	for (order = 0; order < MAX_ORDER ; order++) {
		INIT_LIST_HEAD(&zone->free_area[order].free_list);
		zone->free_area[order].nr_free = 0;
	}
}

#ifndef __HAVE_ARCH_MEMMAP_INIT
#define memmap_init(size, nid, zone, start_pfn) \
	memmap_init_zone((size), (nid), (zone), (start_pfn))
#endif

1898
static int __cpuinit zone_batchsize(struct zone *zone)
1899 1900 1901 1902 1903
{
	int batch;

	/*
	 * The per-cpu-pages pools are set to around 1000th of the
1904
	 * size of the zone.  But no more than 1/2 of a meg.
1905 1906 1907 1908
	 *
	 * OK, so we don't know how big the cache is.  So guess.
	 */
	batch = zone->present_pages / 1024;
1909 1910
	if (batch * PAGE_SIZE > 512 * 1024)
		batch = (512 * 1024) / PAGE_SIZE;
1911 1912 1913 1914 1915
	batch /= 4;		/* We effectively *= 4 below */
	if (batch < 1)
		batch = 1;

	/*
1916 1917 1918
	 * 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.
1919
	 *
1920 1921 1922 1923
	 * 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.
1924
	 */
1925
	batch = (1 << (fls(batch + batch/2)-1)) - 1;
1926

1927 1928 1929
	return batch;
}

1930 1931 1932 1933
inline void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
{
	struct per_cpu_pages *pcp;

1934 1935
	memset(p, 0, sizeof(*p));

1936 1937 1938 1939 1940 1941 1942 1943 1944
	pcp = &p->pcp[0];		/* hot */
	pcp->count = 0;
	pcp->high = 6 * batch;
	pcp->batch = max(1UL, 1 * batch);
	INIT_LIST_HEAD(&pcp->list);

	pcp = &p->pcp[1];		/* cold*/
	pcp->count = 0;
	pcp->high = 2 * batch;
1945
	pcp->batch = max(1UL, batch/2);
1946 1947 1948
	INIT_LIST_HEAD(&pcp->list);
}

1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966
/*
 * 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;

	pcp = &p->pcp[0]; /* hot list */
	pcp->high = high;
	pcp->batch = max(1UL, high/4);
	if ((high/4) > (PAGE_SHIFT * 8))
		pcp->batch = PAGE_SHIFT * 8;
}


1967 1968
#ifdef CONFIG_NUMA
/*
1969 1970 1971 1972 1973 1974 1975
 * 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.
1976 1977 1978 1979 1980 1981 1982 1983
 *
 * 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.
1984
 */
1985
static struct per_cpu_pageset boot_pageset[NR_CPUS];
1986 1987 1988

/*
 * Dynamically allocate memory for the
1989 1990
 * per cpu pageset array in struct zone.
 */
1991
static int __cpuinit process_zones(int cpu)
1992 1993 1994 1995 1996
{
	struct zone *zone, *dzone;

	for_each_zone(zone) {

1997 1998 1999
		if (!populated_zone(zone))
			continue;

N
Nick Piggin 已提交
2000
		zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset),
2001
					 GFP_KERNEL, cpu_to_node(cpu));
N
Nick Piggin 已提交
2002
		if (!zone_pcp(zone, cpu))
2003 2004
			goto bad;

N
Nick Piggin 已提交
2005
		setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone));
2006 2007 2008 2009

		if (percpu_pagelist_fraction)
			setup_pagelist_highmark(zone_pcp(zone, cpu),
			 	(zone->present_pages / percpu_pagelist_fraction));
2010 2011 2012 2013 2014 2015 2016
	}

	return 0;
bad:
	for_each_zone(dzone) {
		if (dzone == zone)
			break;
N
Nick Piggin 已提交
2017 2018
		kfree(zone_pcp(dzone, cpu));
		zone_pcp(dzone, cpu) = NULL;
2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029
	}
	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);

2030 2031 2032
		/* Free per_cpu_pageset if it is slab allocated */
		if (pset != &boot_pageset[cpu])
			kfree(pset);
2033 2034 2035 2036
		zone_pcp(zone, cpu) = NULL;
	}
}

2037
static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb,
2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048
		unsigned long action,
		void *hcpu)
{
	int cpu = (long)hcpu;
	int ret = NOTIFY_OK;

	switch (action) {
		case CPU_UP_PREPARE:
			if (process_zones(cpu))
				ret = NOTIFY_BAD;
			break;
2049
		case CPU_UP_CANCELED:
2050 2051 2052 2053 2054 2055 2056 2057 2058
		case CPU_DEAD:
			free_zone_pagesets(cpu);
			break;
		default:
			break;
	}
	return ret;
}

2059
static struct notifier_block __cpuinitdata pageset_notifier =
2060 2061
	{ &pageset_cpuup_callback, NULL, 0 };

2062
void __init setup_per_cpu_pageset(void)
2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076
{
	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

2077
static __meminit
2078
int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
2079 2080 2081
{
	int i;
	struct pglist_data *pgdat = zone->zone_pgdat;
2082
	size_t alloc_size;
2083 2084 2085 2086 2087

	/*
	 * The per-page waitqueue mechanism uses hashed waitqueues
	 * per zone.
	 */
2088 2089 2090 2091
	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);
2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112
	alloc_size = zone->wait_table_hash_nr_entries
					* sizeof(wait_queue_head_t);

 	if (system_state == SYSTEM_BOOTING) {
		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.
		 */
		zone->wait_table = (wait_queue_head_t *)vmalloc(alloc_size);
	}
	if (!zone->wait_table)
		return -ENOMEM;
2113

2114
	for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
2115
		init_waitqueue_head(zone->wait_table + i);
2116 2117

	return 0;
2118 2119
}

2120
static __meminit void zone_pcp_init(struct zone *zone)
2121 2122 2123 2124 2125 2126 2127
{
	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
2128
		zone_pcp(zone, cpu) = &boot_pageset[cpu];
2129 2130 2131 2132 2133
		setup_pageset(&boot_pageset[cpu],0);
#else
		setup_pageset(zone_pcp(zone,cpu), batch);
#endif
	}
A
Anton Blanchard 已提交
2134 2135 2136
	if (zone->present_pages)
		printk(KERN_DEBUG "  %s zone: %lu pages, LIFO batch:%lu\n",
			zone->name, zone->present_pages, batch);
2137 2138
}

2139 2140 2141
__meminit int init_currently_empty_zone(struct zone *zone,
					unsigned long zone_start_pfn,
					unsigned long size)
2142 2143
{
	struct pglist_data *pgdat = zone->zone_pgdat;
2144 2145 2146 2147
	int ret;
	ret = zone_wait_table_init(zone, size);
	if (ret)
		return ret;
2148 2149 2150 2151 2152 2153 2154
	pgdat->nr_zones = zone_idx(zone) + 1;

	zone->zone_start_pfn = zone_start_pfn;

	memmap_init(size, pgdat->node_id, zone_idx(zone), zone_start_pfn);

	zone_init_free_lists(pgdat, zone, zone->spanned_pages);
2155 2156

	return 0;
2157 2158
}

2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217
#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
 */
static int __init first_active_region_index_in_nid(int nid)
{
	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
 * Note: nid == MAX_NUMNODES returns next region regardles of node
 */
static int __init next_active_region_index_in_nid(int index, int nid)
{
	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
 */
int __init early_pfn_to_nid(unsigned long pfn)
{
	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;
	}

	return 0;
}
#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */

/* 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
2218 2219
 * @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
2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248
 *
 * 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);
	}
}

/**
 * sparse_memory_present_with_active_regions - Call memory_present for each active range
2249
 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
2250 2251 2252
 *
 * If an architecture guarantees that all ranges registered with
 * add_active_ranges() contain no holes and may be freed, this
2253
 * function may be used instead of calling memory_present() manually.
2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264
 */
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);
}

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
/**
 * push_node_boundaries - Push node boundaries to at least the requested boundary
 * @nid: The nid of the node to push the boundary for
 * @start_pfn: The start pfn of the node
 * @end_pfn: The end pfn of the node
 *
 * In reserve-based hot-add, mem_map is allocated that is unused until hotadd
 * time. Specifically, on x86_64, SRAT will report ranges that can potentially
 * be hotplugged even though no physical memory exists. This function allows
 * an arch to push out the node boundaries so mem_map is allocated that can
 * be used later.
 */
#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
void __init push_node_boundaries(unsigned int nid,
		unsigned long start_pfn, unsigned long end_pfn)
{
	printk(KERN_DEBUG "Entering push_node_boundaries(%u, %lu, %lu)\n",
			nid, start_pfn, end_pfn);

	/* Initialise the boundary for this node if necessary */
	if (node_boundary_end_pfn[nid] == 0)
		node_boundary_start_pfn[nid] = -1UL;

	/* Update the boundaries */
	if (node_boundary_start_pfn[nid] > start_pfn)
		node_boundary_start_pfn[nid] = start_pfn;
	if (node_boundary_end_pfn[nid] < end_pfn)
		node_boundary_end_pfn[nid] = end_pfn;
}

/* If necessary, push the node boundary out for reserve hotadd */
static void __init account_node_boundary(unsigned int nid,
		unsigned long *start_pfn, unsigned long *end_pfn)
{
	printk(KERN_DEBUG "Entering account_node_boundary(%u, %lu, %lu)\n",
			nid, *start_pfn, *end_pfn);

	/* Return if boundary information has not been provided */
	if (node_boundary_end_pfn[nid] == 0)
		return;

	/* Check the boundaries and update if necessary */
	if (node_boundary_start_pfn[nid] < *start_pfn)
		*start_pfn = node_boundary_start_pfn[nid];
	if (node_boundary_end_pfn[nid] > *end_pfn)
		*end_pfn = node_boundary_end_pfn[nid];
}
#else
void __init push_node_boundaries(unsigned int nid,
		unsigned long start_pfn, unsigned long end_pfn) {}

static void __init account_node_boundary(unsigned int nid,
		unsigned long *start_pfn, unsigned long *end_pfn) {}
#endif


2321 2322
/**
 * get_pfn_range_for_nid - Return the start and end page frames for a node
2323 2324 2325
 * @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.
2326 2327 2328 2329
 *
 * 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
2330
 * PFNs will be 0.
2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347
 */
void __init get_pfn_range_for_nid(unsigned int nid,
			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);
	}

	if (*start_pfn == -1UL) {
		printk(KERN_WARNING "Node %u active with no memory\n", nid);
		*start_pfn = 0;
	}
2348 2349 2350

	/* Push the node boundaries out if requested */
	account_node_boundary(nid, start_pfn, end_pfn);
2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382
}

/*
 * 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()
 */
unsigned long __init zone_spanned_pages_in_node(int nid,
					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];

	/* 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,
2383
 * then all holes in the requested range will be accounted for.
2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397
 */
unsigned long __init __absent_pages_in_range(int nid,
				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;

2398 2399 2400 2401
	/* Account for ranges before physical memory on this node */
	if (early_node_map[i].start_pfn > range_start_pfn)
		hole_pages = early_node_map[i].start_pfn - range_start_pfn;

2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422
	prev_end_pfn = early_node_map[i].start_pfn;

	/* 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;
	}

2423 2424
	/* Account for ranges past physical memory on this node */
	if (range_end_pfn > prev_end_pfn)
2425
		hole_pages += range_end_pfn -
2426 2427
				max(range_start_pfn, prev_end_pfn);

2428 2429 2430 2431 2432 2433 2434 2435
	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
 *
2436
 * It returns the number of pages frames in memory holes within a range.
2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448
 */
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 */
unsigned long __init zone_absent_pages_in_node(int nid,
					unsigned long zone_type,
					unsigned long *ignored)
{
2449 2450 2451 2452 2453 2454 2455 2456 2457 2458
	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);

	return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
2459
}
2460

2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477
#else
static inline unsigned long zone_spanned_pages_in_node(int nid,
					unsigned long zone_type,
					unsigned long *zones_size)
{
	return zones_size[zone_type];
}

static inline unsigned long zone_absent_pages_in_node(int nid,
						unsigned long zone_type,
						unsigned long *zholes_size)
{
	if (!zholes_size)
		return 0;

	return zholes_size[zone_type];
}
2478

2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501
#endif

static void __init calculate_node_totalpages(struct pglist_data *pgdat,
		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);
}

L
Linus Torvalds 已提交
2502 2503 2504 2505 2506 2507
/*
 * Set up the zone data structures:
 *   - mark all pages reserved
 *   - mark all memory queues empty
 *   - clear the memory bitmaps
 */
2508
static void __meminit free_area_init_core(struct pglist_data *pgdat,
L
Linus Torvalds 已提交
2509 2510
		unsigned long *zones_size, unsigned long *zholes_size)
{
2511
	enum zone_type j;
2512
	int nid = pgdat->node_id;
L
Linus Torvalds 已提交
2513
	unsigned long zone_start_pfn = pgdat->node_start_pfn;
2514
	int ret;
L
Linus Torvalds 已提交
2515

2516
	pgdat_resize_init(pgdat);
L
Linus Torvalds 已提交
2517 2518 2519 2520 2521 2522
	pgdat->nr_zones = 0;
	init_waitqueue_head(&pgdat->kswapd_wait);
	pgdat->kswapd_max_order = 0;
	
	for (j = 0; j < MAX_NR_ZONES; j++) {
		struct zone *zone = pgdat->node_zones + j;
2523
		unsigned long size, realsize, memmap_pages;
L
Linus Torvalds 已提交
2524

2525 2526 2527
		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
2528

2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551
		/*
		 * 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
		 */
		memmap_pages = (size * sizeof(struct page)) >> PAGE_SHIFT;
		if (realsize >= memmap_pages) {
			realsize -= memmap_pages;
			printk(KERN_DEBUG
				"  %s zone: %lu pages used for memmap\n",
				zone_names[j], memmap_pages);
		} else
			printk(KERN_WARNING
				"  %s zone: %lu pages exceeds realsize %lu\n",
				zone_names[j], memmap_pages, realsize);

		/* Account for reserved DMA pages */
		if (j == ZONE_DMA && realsize > dma_reserve) {
			realsize -= dma_reserve;
			printk(KERN_DEBUG "  DMA zone: %lu pages reserved\n",
								dma_reserve);
		}

2552
		if (!is_highmem_idx(j))
L
Linus Torvalds 已提交
2553 2554 2555 2556 2557
			nr_kernel_pages += realsize;
		nr_all_pages += realsize;

		zone->spanned_pages = size;
		zone->present_pages = realsize;
2558
#ifdef CONFIG_NUMA
2559
		zone->node = nid;
2560
		zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
2561
						/ 100;
2562
		zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
2563
#endif
L
Linus Torvalds 已提交
2564 2565 2566
		zone->name = zone_names[j];
		spin_lock_init(&zone->lock);
		spin_lock_init(&zone->lru_lock);
2567
		zone_seqlock_init(zone);
L
Linus Torvalds 已提交
2568 2569 2570
		zone->zone_pgdat = pgdat;
		zone->free_pages = 0;

2571
		zone->prev_priority = DEF_PRIORITY;
L
Linus Torvalds 已提交
2572

2573
		zone_pcp_init(zone);
L
Linus Torvalds 已提交
2574 2575 2576 2577 2578 2579
		INIT_LIST_HEAD(&zone->active_list);
		INIT_LIST_HEAD(&zone->inactive_list);
		zone->nr_scan_active = 0;
		zone->nr_scan_inactive = 0;
		zone->nr_active = 0;
		zone->nr_inactive = 0;
2580
		zap_zone_vm_stats(zone);
2581
		atomic_set(&zone->reclaim_in_progress, 0);
L
Linus Torvalds 已提交
2582 2583 2584
		if (!size)
			continue;

2585 2586
		ret = init_currently_empty_zone(zone, zone_start_pfn, size);
		BUG_ON(ret);
L
Linus Torvalds 已提交
2587 2588 2589 2590 2591 2592 2593 2594 2595 2596
		zone_start_pfn += size;
	}
}

static void __init alloc_node_mem_map(struct pglist_data *pgdat)
{
	/* Skip empty nodes */
	if (!pgdat->node_spanned_pages)
		return;

A
Andy Whitcroft 已提交
2597
#ifdef CONFIG_FLAT_NODE_MEM_MAP
L
Linus Torvalds 已提交
2598 2599
	/* ia64 gets its own node_mem_map, before this, without bootmem */
	if (!pgdat->node_mem_map) {
2600
		unsigned long size, start, end;
A
Andy Whitcroft 已提交
2601 2602
		struct page *map;

2603 2604 2605 2606 2607 2608 2609 2610 2611
		/*
		 * 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);
2612 2613 2614
		map = alloc_remap(pgdat->node_id, size);
		if (!map)
			map = alloc_bootmem_node(pgdat, size);
2615
		pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
L
Linus Torvalds 已提交
2616
	}
A
Andy Whitcroft 已提交
2617
#ifdef CONFIG_FLATMEM
L
Linus Torvalds 已提交
2618 2619 2620
	/*
	 * With no DISCONTIG, the global mem_map is just set as node 0's
	 */
2621
	if (pgdat == NODE_DATA(0)) {
L
Linus Torvalds 已提交
2622
		mem_map = NODE_DATA(0)->node_mem_map;
2623 2624 2625 2626 2627
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
		if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
			mem_map -= pgdat->node_start_pfn;
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
	}
L
Linus Torvalds 已提交
2628
#endif
A
Andy Whitcroft 已提交
2629
#endif /* CONFIG_FLAT_NODE_MEM_MAP */
L
Linus Torvalds 已提交
2630 2631
}

2632
void __meminit free_area_init_node(int nid, struct pglist_data *pgdat,
L
Linus Torvalds 已提交
2633 2634 2635 2636 2637
		unsigned long *zones_size, unsigned long node_start_pfn,
		unsigned long *zholes_size)
{
	pgdat->node_id = nid;
	pgdat->node_start_pfn = node_start_pfn;
2638
	calculate_node_totalpages(pgdat, zones_size, zholes_size);
L
Linus Torvalds 已提交
2639 2640 2641 2642 2643 2644

	alloc_node_mem_map(pgdat);

	free_area_init_core(pgdat, zones_size, zholes_size);
}

2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
/**
 * 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;

	printk(KERN_DEBUG "Entering add_active_range(%d, %lu, %lu) "
			  "%d entries of %d used\n",
			  nid, start_pfn, end_pfn,
			  nr_nodemap_entries, MAX_ACTIVE_REGIONS);

	/* 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;
}

/**
 * shrink_active_range - Shrink an existing registered range of PFNs
 * @nid: The node id the range is on that should be shrunk
 * @old_end_pfn: The old end PFN of the range
 * @new_end_pfn: The new PFN of the range
 *
 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
 * The map is kept at the end physical page range that has already been
 * registered with add_active_range(). This function allows an arch to shrink
 * an existing registered range.
 */
void __init shrink_active_range(unsigned int nid, unsigned long old_end_pfn,
						unsigned long new_end_pfn)
{
	int i;

	/* Find the old active region end and shrink */
	for_each_active_range_index_in_nid(i, nid)
		if (early_node_map[i].end_pfn == old_end_pfn) {
			early_node_map[i].end_pfn = new_end_pfn;
			break;
		}
}

/**
 * remove_all_active_ranges - Remove all currently registered regions
2732
 *
2733 2734 2735 2736
 * 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.
 */
2737
void __init remove_all_active_ranges(void)
2738 2739 2740
{
	memset(early_node_map, 0, sizeof(early_node_map));
	nr_nodemap_entries = 0;
2741 2742 2743 2744
#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
	memset(node_boundary_start_pfn, 0, sizeof(node_boundary_start_pfn));
	memset(node_boundary_end_pfn, 0, sizeof(node_boundary_end_pfn));
#endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774
}

/* 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);
}

/* Find the lowest pfn for a node. This depends on a sorted early_node_map */
unsigned long __init find_min_pfn_for_node(unsigned long nid)
{
	int i;

2775 2776 2777
	/* Regions in the early_node_map can be in any order */
	sort_node_map();

2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789
	/* Assuming a sorted map, the first range found has the starting pfn */
	for_each_active_range_index_in_nid(i, nid)
		return early_node_map[i].start_pfn;

	printk(KERN_WARNING "Could not find start_pfn for node %lu\n", nid);
	return 0;
}

/**
 * find_min_pfn_with_active_regions - Find the minimum PFN registered
 *
 * It returns the minimum PFN based on information provided via
2790
 * add_active_range().
2791 2792 2793 2794 2795 2796 2797 2798 2799 2800
 */
unsigned long __init find_min_pfn_with_active_regions(void)
{
	return find_min_pfn_for_node(MAX_NUMNODES);
}

/**
 * find_max_pfn_with_active_regions - Find the maximum PFN registered
 *
 * It returns the maximum PFN based on information provided via
2801
 * add_active_range().
2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815
 */
unsigned long __init find_max_pfn_with_active_regions(void)
{
	int i;
	unsigned long max_pfn = 0;

	for (i = 0; i < nr_nodemap_entries; i++)
		max_pfn = max(max_pfn, early_node_map[i].end_pfn);

	return max_pfn;
}

/**
 * free_area_init_nodes - Initialise all pg_data_t and zone data
2816
 * @max_zone_pfn: an array of max PFNs for each zone
2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869
 *
 * 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;
	enum zone_type i;

	/* 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++) {
		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]);
	}

	/* Print out the zone ranges */
	printk("Zone PFN ranges:\n");
	for (i = 0; i < MAX_NR_ZONES; i++)
		printk("  %-8s %8lu -> %8lu\n",
				zone_names[i],
				arch_zone_lowest_possible_pfn[i],
				arch_zone_highest_possible_pfn[i]);

	/* 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++)
		printk("  %3d: %8lu -> %8lu\n", early_node_map[i].nid,
						early_node_map[i].start_pfn,
						early_node_map[i].end_pfn);

	/* Initialise every node */
	for_each_online_node(nid) {
		pg_data_t *pgdat = NODE_DATA(nid);
		free_area_init_node(nid, pgdat, NULL,
				find_min_pfn_for_node(nid), NULL);
	}
}
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */

2870
/**
2871 2872
 * set_dma_reserve - set the specified number of pages reserved in the first zone
 * @new_dma_reserve: The number of pages to mark reserved
2873 2874 2875 2876
 *
 * 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
2877 2878 2879
 * 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.
2880 2881 2882 2883 2884 2885
 */
void __init set_dma_reserve(unsigned long new_dma_reserve)
{
	dma_reserve = new_dma_reserve;
}

2886
#ifndef CONFIG_NEED_MULTIPLE_NODES
L
Linus Torvalds 已提交
2887 2888 2889 2890
static bootmem_data_t contig_bootmem_data;
struct pglist_data contig_page_data = { .bdata = &contig_bootmem_data };

EXPORT_SYMBOL(contig_page_data);
2891
#endif
L
Linus Torvalds 已提交
2892 2893 2894

void __init free_area_init(unsigned long *zones_size)
{
2895
	free_area_init_node(0, NODE_DATA(0), zones_size,
L
Linus Torvalds 已提交
2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907
			__pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
}

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

	if (action == CPU_DEAD) {
		local_irq_disable();
		__drain_pages(cpu);
2908
		vm_events_fold_cpu(cpu);
L
Linus Torvalds 已提交
2909
		local_irq_enable();
2910
		refresh_cpu_vm_stats(cpu);
L
Linus Torvalds 已提交
2911 2912 2913 2914 2915 2916 2917 2918 2919 2920
	}
	return NOTIFY_OK;
}
#endif /* CONFIG_HOTPLUG_CPU */

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

2921 2922 2923 2924 2925 2926 2927 2928
/*
 * 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;
2929
	enum zone_type i, j;
2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952

	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];
			}

			/* we treat pages_high as reserved pages. */
			max += zone->pages_high;

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

L
Linus Torvalds 已提交
2953 2954 2955 2956 2957 2958 2959 2960 2961
/*
 * 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;
2962
	enum zone_type j, idx;
L
Linus Torvalds 已提交
2963

2964
	for_each_online_pgdat(pgdat) {
L
Linus Torvalds 已提交
2965 2966 2967 2968 2969 2970
		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;

2971 2972
			idx = j;
			while (idx) {
L
Linus Torvalds 已提交
2973 2974
				struct zone *lower_zone;

2975 2976
				idx--;

L
Linus Torvalds 已提交
2977 2978 2979 2980 2981 2982 2983 2984 2985 2986
				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;
			}
		}
	}
2987 2988 2989

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
2990 2991
}

2992 2993 2994 2995 2996
/**
 * setup_per_zone_pages_min - called when min_free_kbytes changes.
 *
 * Ensures that the pages_{min,low,high} values for each zone are set correctly
 * with respect to min_free_kbytes.
L
Linus Torvalds 已提交
2997
 */
2998
void setup_per_zone_pages_min(void)
L
Linus Torvalds 已提交
2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011
{
	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) {
3012 3013
		u64 tmp;

L
Linus Torvalds 已提交
3014
		spin_lock_irqsave(&zone->lru_lock, flags);
3015 3016
		tmp = (u64)pages_min * zone->present_pages;
		do_div(tmp, lowmem_pages);
L
Linus Torvalds 已提交
3017 3018
		if (is_highmem(zone)) {
			/*
N
Nick Piggin 已提交
3019 3020 3021 3022 3023 3024 3025
			 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
			 * need highmem pages, so cap pages_min to a small
			 * value here.
			 *
			 * The (pages_high-pages_low) and (pages_low-pages_min)
			 * deltas controls asynch page reclaim, and so should
			 * not be capped for highmem.
L
Linus Torvalds 已提交
3026 3027 3028 3029 3030 3031 3032 3033 3034 3035
			 */
			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;
			zone->pages_min = min_pages;
		} else {
N
Nick Piggin 已提交
3036 3037
			/*
			 * If it's a lowmem zone, reserve a number of pages
L
Linus Torvalds 已提交
3038 3039
			 * proportionate to the zone's size.
			 */
N
Nick Piggin 已提交
3040
			zone->pages_min = tmp;
L
Linus Torvalds 已提交
3041 3042
		}

3043 3044
		zone->pages_low   = zone->pages_min + (tmp >> 2);
		zone->pages_high  = zone->pages_min + (tmp >> 1);
L
Linus Torvalds 已提交
3045 3046
		spin_unlock_irqrestore(&zone->lru_lock, flags);
	}
3047 3048 3049

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105
}

/*
 * 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
 */
static int __init init_per_zone_pages_min(void)
{
	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;
	setup_per_zone_pages_min();
	setup_per_zone_lowmem_reserve();
	return 0;
}
module_init(init_per_zone_pages_min)

/*
 * 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);
	setup_per_zone_pages_min();
	return 0;
}

3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117
#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)
3118
		zone->min_unmapped_pages = (zone->present_pages *
3119 3120 3121
				sysctl_min_unmapped_ratio) / 100;
	return 0;
}
3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137

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;
}
3138 3139
#endif

L
Linus Torvalds 已提交
3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156
/*
 * 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
 * pages_min watermarks. The lowmem reserve ratio can only make sense
 * 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;
}

3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182
/*
 * 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;
	for_each_zone(zone) {
		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;
}

3183
int hashdist = HASHDIST_DEFAULT;
L
Linus Torvalds 已提交
3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228

#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 */
		numentries = (flags & HASH_HIGHMEM) ? nr_all_pages : nr_kernel_pages;
		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);
	}
3229
	numentries = roundup_pow_of_two(numentries);
L
Linus Torvalds 已提交
3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271

	/* 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;

	log2qty = long_log2(numentries);

	do {
		size = bucketsize << log2qty;
		if (flags & HASH_EARLY)
			table = alloc_bootmem(size);
		else if (hashdist)
			table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
		else {
			unsigned long order;
			for (order = 0; ((1UL << order) << PAGE_SHIFT) < size; order++)
				;
			table = (void*) __get_free_pages(GFP_ATOMIC, order);
		}
	} while (!table && size > PAGE_SIZE && --log2qty);

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

	printk("%s hash table entries: %d (order: %d, %lu bytes)\n",
	       tablename,
	       (1U << log2qty),
	       long_log2(size) - PAGE_SHIFT,
	       size);

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

	return table;
}
3272 3273 3274 3275

#ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
struct page *pfn_to_page(unsigned long pfn)
{
3276
	return __pfn_to_page(pfn);
3277 3278 3279
}
unsigned long page_to_pfn(struct page *page)
{
3280
	return __page_to_pfn(page);
3281 3282 3283 3284
}
EXPORT_SYMBOL(pfn_to_page);
EXPORT_SYMBOL(page_to_pfn);
#endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */
3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300

#if MAX_NUMNODES > 1
/*
 * Find the highest possible node id.
 */
int highest_possible_node_id(void)
{
	unsigned int node;
	unsigned int highest = 0;

	for_each_node_mask(node, node_possible_map)
		highest = node;
	return highest;
}
EXPORT_SYMBOL(highest_possible_node_id);
#endif