page_alloc.c 64.1 KB
Newer Older
Linus Torvalds's avatar
Linus Torvalds committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
/*
 *  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/config.h>
#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>
25
#include <linux/kernel.h>
Linus Torvalds's avatar
Linus Torvalds committed
26 27 28 29 30 31 32 33 34 35
#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>
36
#include <linux/memory_hotplug.h>
Linus Torvalds's avatar
Linus Torvalds committed
37 38 39 40 41 42 43 44 45 46
#include <linux/nodemask.h>
#include <linux/vmalloc.h>

#include <asm/tlbflush.h>
#include "internal.h"

/*
 * MCD - HACK: Find somewhere to initialize this EARLY, or make this
 * initializer cleaner
 */
47
nodemask_t node_online_map __read_mostly = { { [0] = 1UL } };
48
EXPORT_SYMBOL(node_online_map);
49
nodemask_t node_possible_map __read_mostly = NODE_MASK_ALL;
50
EXPORT_SYMBOL(node_possible_map);
51
struct pglist_data *pgdat_list __read_mostly;
52 53
unsigned long totalram_pages __read_mostly;
unsigned long totalhigh_pages __read_mostly;
Linus Torvalds's avatar
Linus Torvalds committed
54 55 56 57 58 59 60 61 62
long nr_swap_pages;

/*
 * 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
63 64 65
 *
 * TBD: should special case ZONE_DMA32 machines here - in those we normally
 * don't need any ZONE_NORMAL reservation
Linus Torvalds's avatar
Linus Torvalds committed
66
 */
67
int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { 256, 256, 32 };
Linus Torvalds's avatar
Linus Torvalds committed
68 69 70 71 72 73 74

EXPORT_SYMBOL(totalram_pages);

/*
 * Used by page_zone() to look up the address of the struct zone whose
 * id is encoded in the upper bits of page->flags
 */
75
struct zone *zone_table[1 << ZONETABLE_SHIFT] __read_mostly;
Linus Torvalds's avatar
Linus Torvalds committed
76 77
EXPORT_SYMBOL(zone_table);

78
static char *zone_names[MAX_NR_ZONES] = { "DMA", "DMA32", "Normal", "HighMem" };
Linus Torvalds's avatar
Linus Torvalds committed
79 80 81 82 83
int min_free_kbytes = 1024;

unsigned long __initdata nr_kernel_pages;
unsigned long __initdata nr_all_pages;

Nick Piggin's avatar
Nick Piggin committed
84
#ifdef CONFIG_DEBUG_VM
85
static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
Linus Torvalds's avatar
Linus Torvalds committed
86
{
87 88 89
	int ret = 0;
	unsigned seq;
	unsigned long pfn = page_to_pfn(page);
90

91 92 93 94 95 96 97 98 99
	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;
100 101 102 103
}

static int page_is_consistent(struct zone *zone, struct page *page)
{
Linus Torvalds's avatar
Linus Torvalds committed
104 105
#ifdef CONFIG_HOLES_IN_ZONE
	if (!pfn_valid(page_to_pfn(page)))
106
		return 0;
Linus Torvalds's avatar
Linus Torvalds committed
107 108
#endif
	if (zone != page_zone(page))
109 110 111 112 113 114 115 116 117 118
		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))
Linus Torvalds's avatar
Linus Torvalds committed
119
		return 1;
120 121 122
	if (!page_is_consistent(zone, page))
		return 1;

Linus Torvalds's avatar
Linus Torvalds committed
123 124 125
	return 0;
}

Nick Piggin's avatar
Nick Piggin committed
126 127 128 129 130 131 132
#else
static inline int bad_range(struct zone *zone, struct page *page)
{
	return 0;
}
#endif

Linus Torvalds's avatar
Linus Torvalds committed
133 134 135 136 137
static void bad_page(const char *function, struct page *page)
{
	printk(KERN_EMERG "Bad page state at %s (in process '%s', page %p)\n",
		function, current->comm, page);
	printk(KERN_EMERG "flags:0x%0*lx mapping:%p mapcount:%d count:%d\n",
138
		(int)(2*sizeof(unsigned long)), (unsigned long)page->flags,
Linus Torvalds's avatar
Linus Torvalds committed
139 140 141 142
		page->mapping, page_mapcount(page), page_count(page));
	printk(KERN_EMERG "Backtrace:\n");
	dump_stack();
	printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n");
143 144
	page->flags &= ~(1 << PG_lru	|
			1 << PG_private |
Linus Torvalds's avatar
Linus Torvalds committed
145 146 147
			1 << PG_locked	|
			1 << PG_active	|
			1 << PG_dirty	|
148 149
			1 << PG_reclaim |
			1 << PG_slab    |
Linus Torvalds's avatar
Linus Torvalds committed
150
			1 << PG_swapcache |
151
			1 << PG_writeback );
Linus Torvalds's avatar
Linus Torvalds committed
152 153 154
	set_page_count(page, 0);
	reset_page_mapcount(page);
	page->mapping = NULL;
155
	add_taint(TAINT_BAD_PAGE);
Linus Torvalds's avatar
Linus Torvalds committed
156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185
}

/*
 * 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).
 *
 * The first tail page's ->mapping, if non-zero, holds the address of the
 * compound page's put_page() function.
 *
 * The order of the allocation is stored in the first tail page's ->index
 * This is only for debug at present.  This usage means that zero-order pages
 * may not be compound.
 */
static void prep_compound_page(struct page *page, unsigned long order)
{
	int i;
	int nr_pages = 1 << order;

	page[1].mapping = NULL;
	page[1].index = order;
	for (i = 0; i < nr_pages; i++) {
		struct page *p = page + i;

		SetPageCompound(p);
186
		set_page_private(p, (unsigned long)page);
Linus Torvalds's avatar
Linus Torvalds committed
187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205
	}
}

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

	if (!PageCompound(page))
		return;

	if (page[1].index != order)
		bad_page(__FUNCTION__, page);

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

		if (!PageCompound(p))
			bad_page(__FUNCTION__, page);
206
		if (page_private(p) != (unsigned long)page)
Linus Torvalds's avatar
Linus Torvalds committed
207 208 209 210 211 212 213 214 215 216 217
			bad_page(__FUNCTION__, page);
		ClearPageCompound(p);
	}
}

/*
 * 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.
 */
static inline unsigned long page_order(struct page *page) {
218
	return page_private(page);
Linus Torvalds's avatar
Linus Torvalds committed
219 220 221
}

static inline void set_page_order(struct page *page, int order) {
222
	set_page_private(page, order);
Linus Torvalds's avatar
Linus Torvalds committed
223 224 225 226 227 228
	__SetPagePrivate(page);
}

static inline void rmv_page_order(struct page *page)
{
	__ClearPagePrivate(page);
229
	set_page_private(page, 0);
Linus Torvalds's avatar
Linus Torvalds committed
230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265
}

/*
 * 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)
 *
 * Assumption: *_mem_map is contigious at least up to MAX_ORDER
 */
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
Nick Piggin's avatar
Nick Piggin committed
266 267 268 269
 * (a) the buddy is not in a hole &&
 * (b) the buddy is free &&
 * (c) the buddy is on the buddy system &&
 * (d) a page and its buddy have the same order.
270
 * for recording page's order, we use page_private(page) and PG_private.
Linus Torvalds's avatar
Linus Torvalds committed
271 272 273 274
 *
 */
static inline int page_is_buddy(struct page *page, int order)
{
Nick Piggin's avatar
Nick Piggin committed
275 276 277 278 279
#ifdef CONFIG_HOLES_IN_ZONE
	if (!pfn_valid(page_to_pfn(page)))
		return 0;
#endif

Linus Torvalds's avatar
Linus Torvalds committed
280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300
       if (PagePrivate(page)           &&
           (page_order(page) == order) &&
            page_count(page) == 0)
               return 1;
       return 0;
}

/*
 * 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
 * free pages of length of (1 << order) and marked with PG_Private.Page's
301
 * order is recorded in page_private(page) field.
Linus Torvalds's avatar
Linus Torvalds committed
302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333
 * 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
 */

static inline void __free_pages_bulk (struct page *page,
		struct zone *zone, unsigned int order)
{
	unsigned long page_idx;
	int order_size = 1 << order;

	if (unlikely(order))
		destroy_compound_page(page, order);

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

	BUG_ON(page_idx & (order_size - 1));
	BUG_ON(bad_range(zone, page));

	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);
		if (!page_is_buddy(buddy, order))
			break;		/* Move the buddy up one level. */
Nick Piggin's avatar
Nick Piggin committed
334

Linus Torvalds's avatar
Linus Torvalds committed
335 336 337 338
		list_del(&buddy->lru);
		area = zone->free_area + order;
		area->nr_free--;
		rmv_page_order(buddy);
Nick Piggin's avatar
Nick Piggin committed
339
		combined_idx = __find_combined_index(page_idx, order);
Linus Torvalds's avatar
Linus Torvalds committed
340 341 342 343 344 345 346 347 348
		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++;
}

349
static inline int free_pages_check(const char *function, struct page *page)
Linus Torvalds's avatar
Linus Torvalds committed
350
{
Nick Piggin's avatar
Nick Piggin committed
351 352 353
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
		(page_count(page) != 0)  |
Linus Torvalds's avatar
Linus Torvalds committed
354 355 356 357 358 359 360 361
		(page->flags & (
			1 << PG_lru	|
			1 << PG_private |
			1 << PG_locked	|
			1 << PG_active	|
			1 << PG_reclaim	|
			1 << PG_slab	|
			1 << PG_swapcache |
Nick Piggin's avatar
Nick Piggin committed
362
			1 << PG_writeback |
Nick Piggin's avatar
Nick Piggin committed
363
			1 << PG_reserved ))))
Linus Torvalds's avatar
Linus Torvalds committed
364 365
		bad_page(function, page);
	if (PageDirty(page))
Nick Piggin's avatar
Nick Piggin committed
366
		__ClearPageDirty(page);
367 368 369 370 371 372
	/*
	 * 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);
Linus Torvalds's avatar
Linus Torvalds committed
373 374 375 376 377
}

/*
 * Frees a list of pages. 
 * Assumes all pages on list are in same zone, and of same order.
378
 * count is the number of pages to free.
Linus Torvalds's avatar
Linus Torvalds committed
379 380 381 382 383 384 385 386 387 388 389 390 391 392
 *
 * 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.
 */
static int
free_pages_bulk(struct zone *zone, int count,
		struct list_head *list, unsigned int order)
{
	struct page *page = NULL;
	int ret = 0;

Nick Piggin's avatar
Nick Piggin committed
393
	spin_lock(&zone->lock);
Linus Torvalds's avatar
Linus Torvalds committed
394 395 396 397 398 399 400 401 402
	zone->all_unreclaimable = 0;
	zone->pages_scanned = 0;
	while (!list_empty(list) && count--) {
		page = list_entry(list->prev, struct page, lru);
		/* have to delete it as __free_pages_bulk list manipulates */
		list_del(&page->lru);
		__free_pages_bulk(page, zone, order);
		ret++;
	}
Nick Piggin's avatar
Nick Piggin committed
403
	spin_unlock(&zone->lock);
Linus Torvalds's avatar
Linus Torvalds committed
404 405 406 407 408
	return ret;
}

void __free_pages_ok(struct page *page, unsigned int order)
{
Nick Piggin's avatar
Nick Piggin committed
409
	unsigned long flags;
Linus Torvalds's avatar
Linus Torvalds committed
410 411
	LIST_HEAD(list);
	int i;
412
	int reserved = 0;
Linus Torvalds's avatar
Linus Torvalds committed
413 414 415 416 417 418 419 420 421 422

	arch_free_page(page, order);

#ifndef CONFIG_MMU
	if (order > 0)
		for (i = 1 ; i < (1 << order) ; ++i)
			__put_page(page + i);
#endif

	for (i = 0 ; i < (1 << order) ; ++i)
423 424 425 426
		reserved += free_pages_check(__FUNCTION__, page + i);
	if (reserved)
		return;

Linus Torvalds's avatar
Linus Torvalds committed
427
	list_add(&page->lru, &list);
428
	mod_page_state(pgfree, 1 << order);
Linus Torvalds's avatar
Linus Torvalds committed
429
	kernel_map_pages(page, 1<<order, 0);
Nick Piggin's avatar
Nick Piggin committed
430
	local_irq_save(flags);
Linus Torvalds's avatar
Linus Torvalds committed
431
	free_pages_bulk(page_zone(page), 1, &list, order);
Nick Piggin's avatar
Nick Piggin committed
432
	local_irq_restore(flags);
Linus Torvalds's avatar
Linus Torvalds committed
433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449
}


/*
 * 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
 */
Nick Piggin's avatar
Nick Piggin committed
450
static inline void expand(struct zone *zone, struct page *page,
Linus Torvalds's avatar
Linus Torvalds committed
451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468
 	int low, int high, struct free_area *area)
{
	unsigned long size = 1 << high;

	while (high > low) {
		area--;
		high--;
		size >>= 1;
		BUG_ON(bad_range(zone, &page[size]));
		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
 */
469
static int prep_new_page(struct page *page, int order)
Linus Torvalds's avatar
Linus Torvalds committed
470
{
Nick Piggin's avatar
Nick Piggin committed
471 472 473
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
		(page_count(page) != 0)  |
474 475
		(page->flags & (
			1 << PG_lru	|
Linus Torvalds's avatar
Linus Torvalds committed
476 477 478 479 480
			1 << PG_private	|
			1 << PG_locked	|
			1 << PG_active	|
			1 << PG_dirty	|
			1 << PG_reclaim	|
481
			1 << PG_slab    |
Linus Torvalds's avatar
Linus Torvalds committed
482
			1 << PG_swapcache |
Nick Piggin's avatar
Nick Piggin committed
483
			1 << PG_writeback |
Nick Piggin's avatar
Nick Piggin committed
484
			1 << PG_reserved ))))
Linus Torvalds's avatar
Linus Torvalds committed
485 486
		bad_page(__FUNCTION__, page);

487 488 489 490 491 492 493
	/*
	 * 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;

Linus Torvalds's avatar
Linus Torvalds committed
494 495 496
	page->flags &= ~(1 << PG_uptodate | 1 << PG_error |
			1 << PG_referenced | 1 << PG_arch_1 |
			1 << PG_checked | 1 << PG_mappedtodisk);
497
	set_page_private(page, 0);
Linus Torvalds's avatar
Linus Torvalds committed
498 499
	set_page_refs(page, order);
	kernel_map_pages(page, 1 << order, 1);
500
	return 0;
Linus Torvalds's avatar
Linus Torvalds committed
501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522
}

/* 
 * 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;
Nick Piggin's avatar
Nick Piggin committed
523 524
		expand(zone, page, order, current_order, area);
		return page;
Linus Torvalds's avatar
Linus Torvalds committed
525 526 527 528 529 530 531 532 533 534 535 536 537 538 539
	}

	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;
	
Nick Piggin's avatar
Nick Piggin committed
540
	spin_lock(&zone->lock);
Linus Torvalds's avatar
Linus Torvalds committed
541
	for (i = 0; i < count; ++i) {
Nick Piggin's avatar
Nick Piggin committed
542 543
		struct page *page = __rmqueue(zone, order);
		if (unlikely(page == NULL))
Linus Torvalds's avatar
Linus Torvalds committed
544 545 546
			break;
		list_add_tail(&page->lru, list);
	}
Nick Piggin's avatar
Nick Piggin committed
547
	spin_unlock(&zone->lock);
Nick Piggin's avatar
Nick Piggin committed
548
	return i;
Linus Torvalds's avatar
Linus Torvalds committed
549 550
}

551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580
#ifdef CONFIG_NUMA
/* Called from the slab reaper to drain remote pagesets */
void drain_remote_pages(void)
{
	struct zone *zone;
	int i;
	unsigned long flags;

	local_irq_save(flags);
	for_each_zone(zone) {
		struct per_cpu_pageset *pset;

		/* Do not drain local pagesets */
		if (zone->zone_pgdat->node_id == numa_node_id())
			continue;

		pset = zone->pageset[smp_processor_id()];
		for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) {
			struct per_cpu_pages *pcp;

			pcp = &pset->pcp[i];
			if (pcp->count)
				pcp->count -= free_pages_bulk(zone, pcp->count,
						&pcp->list, 0);
		}
	}
	local_irq_restore(flags);
}
#endif

Linus Torvalds's avatar
Linus Torvalds committed
581 582 583
#if defined(CONFIG_PM) || defined(CONFIG_HOTPLUG_CPU)
static void __drain_pages(unsigned int cpu)
{
Nick Piggin's avatar
Nick Piggin committed
584
	unsigned long flags;
Linus Torvalds's avatar
Linus Torvalds committed
585 586 587 588 589 590
	struct zone *zone;
	int i;

	for_each_zone(zone) {
		struct per_cpu_pageset *pset;

591
		pset = zone_pcp(zone, cpu);
Linus Torvalds's avatar
Linus Torvalds committed
592 593 594 595
		for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) {
			struct per_cpu_pages *pcp;

			pcp = &pset->pcp[i];
Nick Piggin's avatar
Nick Piggin committed
596
			local_irq_save(flags);
Linus Torvalds's avatar
Linus Torvalds committed
597 598
			pcp->count -= free_pages_bulk(zone, pcp->count,
						&pcp->list, 0);
Nick Piggin's avatar
Nick Piggin committed
599
			local_irq_restore(flags);
Linus Torvalds's avatar
Linus Torvalds committed
600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655
		}
	}
}
#endif /* CONFIG_PM || CONFIG_HOTPLUG_CPU */

#ifdef CONFIG_PM

void mark_free_pages(struct zone *zone)
{
	unsigned long zone_pfn, flags;
	int order;
	struct list_head *curr;

	if (!zone->spanned_pages)
		return;

	spin_lock_irqsave(&zone->lock, flags);
	for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
		ClearPageNosaveFree(pfn_to_page(zone_pfn + zone->zone_start_pfn));

	for (order = MAX_ORDER - 1; order >= 0; --order)
		list_for_each(curr, &zone->free_area[order].free_list) {
			unsigned long start_pfn, i;

			start_pfn = page_to_pfn(list_entry(curr, struct page, lru));

			for (i=0; i < (1<<order); i++)
				SetPageNosaveFree(pfn_to_page(start_pfn+i));
	}
	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 */

static void zone_statistics(struct zonelist *zonelist, struct zone *z)
{
#ifdef CONFIG_NUMA
	unsigned long flags;
	int cpu;
	pg_data_t *pg = z->zone_pgdat;
	pg_data_t *orig = zonelist->zones[0]->zone_pgdat;
	struct per_cpu_pageset *p;

	local_irq_save(flags);
	cpu = smp_processor_id();
656
	p = zone_pcp(z,cpu);
Linus Torvalds's avatar
Linus Torvalds committed
657
	if (pg == orig) {
658
		p->numa_hit++;
Linus Torvalds's avatar
Linus Torvalds committed
659 660
	} else {
		p->numa_miss++;
661
		zone_pcp(zonelist->zones[0], cpu)->numa_foreign++;
Linus Torvalds's avatar
Linus Torvalds committed
662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684
	}
	if (pg == NODE_DATA(numa_node_id()))
		p->local_node++;
	else
		p->other_node++;
	local_irq_restore(flags);
#endif
}

/*
 * Free a 0-order page
 */
static void FASTCALL(free_hot_cold_page(struct page *page, int cold));
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;

	arch_free_page(page, 0);

	if (PageAnon(page))
		page->mapping = NULL;
685 686 687 688 689 690
	if (free_pages_check(__FUNCTION__, page))
		return;

	inc_page_state(pgfree);
	kernel_map_pages(page, 1, 0);

691
	pcp = &zone_pcp(zone, get_cpu())->pcp[cold];
Linus Torvalds's avatar
Linus Torvalds committed
692 693 694
	local_irq_save(flags);
	list_add(&page->lru, &pcp->list);
	pcp->count++;
695 696
	if (pcp->count >= pcp->high)
		pcp->count -= free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
Linus Torvalds's avatar
Linus Torvalds committed
697 698 699 700 701 702 703 704 705 706 707 708 709 710
	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);
}

711
static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
Linus Torvalds's avatar
Linus Torvalds committed
712 713 714 715 716 717 718 719 720 721 722 723 724 725
{
	int i;

	BUG_ON((gfp_flags & (__GFP_WAIT | __GFP_HIGHMEM)) == __GFP_HIGHMEM);
	for(i = 0; i < (1 << order); i++)
		clear_highpage(page + i);
}

/*
 * 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.
 */
static struct page *
726
buffered_rmqueue(struct zone *zone, int order, gfp_t gfp_flags)
Linus Torvalds's avatar
Linus Torvalds committed
727 728
{
	unsigned long flags;
729
	struct page *page;
Linus Torvalds's avatar
Linus Torvalds committed
730 731
	int cold = !!(gfp_flags & __GFP_COLD);

732
again:
Linus Torvalds's avatar
Linus Torvalds committed
733 734 735
	if (order == 0) {
		struct per_cpu_pages *pcp;

736
		page = NULL;
737
		pcp = &zone_pcp(zone, get_cpu())->pcp[cold];
Linus Torvalds's avatar
Linus Torvalds committed
738
		local_irq_save(flags);
Nick Piggin's avatar
Nick Piggin committed
739
		if (!pcp->count)
Linus Torvalds's avatar
Linus Torvalds committed
740 741
			pcp->count += rmqueue_bulk(zone, 0,
						pcp->batch, &pcp->list);
Nick Piggin's avatar
Nick Piggin committed
742
		if (likely(pcp->count)) {
Linus Torvalds's avatar
Linus Torvalds committed
743 744 745 746 747 748
			page = list_entry(pcp->list.next, struct page, lru);
			list_del(&page->lru);
			pcp->count--;
		}
		local_irq_restore(flags);
		put_cpu();
Rohit Seth's avatar
Rohit Seth committed
749
	} else {
Linus Torvalds's avatar
Linus Torvalds committed
750 751 752 753 754 755 756 757
		spin_lock_irqsave(&zone->lock, flags);
		page = __rmqueue(zone, order);
		spin_unlock_irqrestore(&zone->lock, flags);
	}

	if (page != NULL) {
		BUG_ON(bad_range(zone, page));
		mod_page_state_zone(zone, pgalloc, 1 << order);
758 759
		if (prep_new_page(page, order))
			goto again;
Linus Torvalds's avatar
Linus Torvalds committed
760 761 762 763 764 765 766 767 768 769

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

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

Rohit Seth's avatar
Rohit Seth committed
770
#define ALLOC_NO_WATERMARKS	0x01 /* don't check watermarks at all */
771 772 773 774 775 776
#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 */
Rohit Seth's avatar
Rohit Seth committed
777

Linus Torvalds's avatar
Linus Torvalds committed
778 779 780 781 782
/*
 * 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,
Rohit Seth's avatar
Rohit Seth committed
783
		      int classzone_idx, int alloc_flags)
Linus Torvalds's avatar
Linus Torvalds committed
784 785 786 787 788
{
	/* free_pages my go negative - that's OK */
	long min = mark, free_pages = z->free_pages - (1 << order) + 1;
	int o;

Rohit Seth's avatar
Rohit Seth committed
789
	if (alloc_flags & ALLOC_HIGH)
Linus Torvalds's avatar
Linus Torvalds committed
790
		min -= min / 2;
Rohit Seth's avatar
Rohit Seth committed
791
	if (alloc_flags & ALLOC_HARDER)
Linus Torvalds's avatar
Linus Torvalds committed
792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808
		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;
}

Rohit Seth's avatar
Rohit Seth committed
809 810 811 812 813 814 815
/*
 * get_page_from_freeliest goes through the zonelist trying to allocate
 * a page.
 */
static struct page *
get_page_from_freelist(gfp_t gfp_mask, unsigned int order,
		struct zonelist *zonelist, int alloc_flags)
Martin Hicks's avatar
Martin Hicks committed
816
{
Rohit Seth's avatar
Rohit Seth committed
817 818 819 820 821 822 823 824 825 826 827 828 829 830
	struct zone **z = zonelist->zones;
	struct page *page = NULL;
	int classzone_idx = zone_idx(*z);

	/*
	 * Go through the zonelist once, looking for a zone with enough free.
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
	 */
	do {
		if ((alloc_flags & ALLOC_CPUSET) &&
				!cpuset_zone_allowed(*z, gfp_mask))
			continue;

		if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
831 832 833 834 835 836 837 838
			unsigned long mark;
			if (alloc_flags & ALLOC_WMARK_MIN)
				mark = (*z)->pages_min;
			else if (alloc_flags & ALLOC_WMARK_LOW)
				mark = (*z)->pages_low;
			else
				mark = (*z)->pages_high;
			if (!zone_watermark_ok(*z, order, mark,
Rohit Seth's avatar
Rohit Seth committed
839 840 841 842 843 844 845 846 847 848 849
				    classzone_idx, alloc_flags))
				continue;
		}

		page = buffered_rmqueue(*z, order, gfp_mask);
		if (page) {
			zone_statistics(zonelist, *z);
			break;
		}
	} while (*(++z) != NULL);
	return page;
Martin Hicks's avatar
Martin Hicks committed
850 851
}

Linus Torvalds's avatar
Linus Torvalds committed
852 853 854 855
/*
 * This is the 'heart' of the zoned buddy allocator.
 */
struct page * fastcall
856
__alloc_pages(gfp_t gfp_mask, unsigned int order,
Linus Torvalds's avatar
Linus Torvalds committed
857 858
		struct zonelist *zonelist)
{
Al Viro's avatar
Al Viro committed
859
	const gfp_t wait = gfp_mask & __GFP_WAIT;
Rohit Seth's avatar
Rohit Seth committed
860
	struct zone **z;
Linus Torvalds's avatar
Linus Torvalds committed
861 862 863 864
	struct page *page;
	struct reclaim_state reclaim_state;
	struct task_struct *p = current;
	int do_retry;
Rohit Seth's avatar
Rohit Seth committed
865
	int alloc_flags;
Linus Torvalds's avatar
Linus Torvalds committed
866 867 868 869
	int did_some_progress;

	might_sleep_if(wait);

870
restart:
Rohit Seth's avatar
Rohit Seth committed
871
	z = zonelist->zones;  /* the list of zones suitable for gfp_mask */
Linus Torvalds's avatar
Linus Torvalds committed
872

Rohit Seth's avatar
Rohit Seth committed
873
	if (unlikely(*z == NULL)) {
Linus Torvalds's avatar
Linus Torvalds committed
874 875 876
		/* Should this ever happen?? */
		return NULL;
	}
877

Rohit Seth's avatar
Rohit Seth committed
878
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order,
879
				zonelist, ALLOC_WMARK_LOW|ALLOC_CPUSET);
Rohit Seth's avatar
Rohit Seth committed
880 881
	if (page)
		goto got_pg;
Linus Torvalds's avatar
Linus Torvalds committed
882

883
	do {
Rohit Seth's avatar
Rohit Seth committed
884
		wakeup_kswapd(*z, order);
885
	} while (*(++z));
Linus Torvalds's avatar
Linus Torvalds committed
886

887
	/*
Rohit Seth's avatar
Rohit Seth committed
888 889 890 891 892 893 894
	 * 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
	 * policy.
895
	 */
896
	alloc_flags = ALLOC_WMARK_MIN;
Rohit Seth's avatar
Rohit Seth committed
897 898 899 900
	if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait)
		alloc_flags |= ALLOC_HARDER;
	if (gfp_mask & __GFP_HIGH)
		alloc_flags |= ALLOC_HIGH;
901
	alloc_flags |= ALLOC_CPUSET;
Linus Torvalds's avatar
Linus Torvalds committed
902 903 904

	/*
	 * Go through the zonelist again. Let __GFP_HIGH and allocations
Rohit Seth's avatar
Rohit Seth committed
905
	 * coming from realtime tasks go deeper into reserves.
Linus Torvalds's avatar
Linus Torvalds committed
906 907 908
	 *
	 * This is the last chance, in general, before the goto nopage.
	 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
909
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
Linus Torvalds's avatar
Linus Torvalds committed
910
	 */
Rohit Seth's avatar
Rohit Seth committed
911 912 913
	page = get_page_from_freelist(gfp_mask, order, zonelist, alloc_flags);
	if (page)
		goto got_pg;
Linus Torvalds's avatar
Linus Torvalds committed
914 915

	/* This allocation should allow future memory freeing. */
916 917 918 919

	if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE)))
			&& !in_interrupt()) {
		if (!(gfp_mask & __GFP_NOMEMALLOC)) {
Kirill Korotaev's avatar
Kirill Korotaev committed
920
nofail_alloc:
921
			/* go through the zonelist yet again, ignoring mins */
Rohit Seth's avatar
Rohit Seth committed
922
			page = get_page_from_freelist(gfp_mask, order,
923
				zonelist, ALLOC_NO_WATERMARKS);
Rohit Seth's avatar
Rohit Seth committed
924 925
			if (page)
				goto got_pg;
Kirill Korotaev's avatar
Kirill Korotaev committed
926 927 928 929
			if (gfp_mask & __GFP_NOFAIL) {
				blk_congestion_wait(WRITE, HZ/50);
				goto nofail_alloc;
			}
Linus Torvalds's avatar
Linus Torvalds committed
930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945
		}
		goto nopage;
	}

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

rebalance:
	cond_resched();

	/* We now go into synchronous reclaim */
	p->flags |= PF_MEMALLOC;
	reclaim_state.reclaimed_slab = 0;
	p->reclaim_state = &reclaim_state;

Rohit Seth's avatar
Rohit Seth committed
946
	did_some_progress = try_to_free_pages(zonelist->zones, gfp_mask);
Linus Torvalds's avatar
Linus Torvalds committed
947 948 949 950 951 952 953

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

	cond_resched();

	if (likely(did_some_progress)) {
Rohit Seth's avatar
Rohit Seth committed
954 955 956 957
		page = get_page_from_freelist(gfp_mask, order,
						zonelist, alloc_flags);
		if (page)
			goto got_pg;
Linus Torvalds's avatar
Linus Torvalds committed
958 959 960 961 962 963 964
	} 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.
		 */
Rohit Seth's avatar
Rohit Seth committed
965
		page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order,
966
				zonelist, ALLOC_WMARK_HIGH|ALLOC_CPUSET);
Rohit Seth's avatar
Rohit Seth committed
967 968
		if (page)
			goto got_pg;
Linus Torvalds's avatar
Linus Torvalds committed
969

970
		out_of_memory(gfp_mask, order);
Linus Torvalds's avatar
Linus Torvalds committed
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
		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) {
		blk_congestion_wait(WRITE, HZ/50);
		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();
Janet Morgan's avatar
Janet Morgan committed
999
		show_mem();
Linus Torvalds's avatar
Linus Torvalds committed
1000 1001 1002 1003 1004 1005 1006 1007 1008 1009
	}
got_pg:
	return page;
}

EXPORT_SYMBOL(__alloc_pages);

/*
 * Common helper functions.
 */
1010
fastcall unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
Linus Torvalds's avatar
Linus Torvalds committed
1011 1012 1013 1014 1015 1016 1017 1018 1019 1020
{
	struct page * page;
	page = alloc_pages(gfp_mask, order);
	if (!page)
		return 0;
	return (unsigned long) page_address(page);
}

EXPORT_SYMBOL(__get_free_pages);

1021
fastcall unsigned long get_zeroed_page(gfp_t gfp_mask)
Linus Torvalds's avatar
Linus Torvalds committed
1022 1023 1024 1025 1026 1027 1028
{
	struct page * page;

	/*
	 * get_zeroed_page() returns a 32-bit address, which cannot represent
	 * a highmem page
	 */
Al Viro's avatar
Al Viro committed
1029
	BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
Linus Torvalds's avatar
Linus Torvalds committed
1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048

	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)
{
Nick Piggin's avatar
Nick Piggin committed
1049
	if (put_page_testzero(page)) {
Linus Torvalds's avatar
Linus Torvalds committed
1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098
		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) {
		BUG_ON(!virt_addr_valid((void *)addr));
		__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)
{
	unsigned int i, sum = 0;

	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)
{
1099 1100
	/* Just pick one node, since fallback list is circular */
	pg_data_t *pgdat = NODE_DATA(numa_node_id());
Linus Torvalds's avatar
Linus Torvalds committed
1101 1102
	unsigned int sum = 0;

1103 1104 1105
	struct zonelist *zonelist = pgdat->node_zonelists + offset;
	struct zone **zonep = zonelist->zones;
	struct zone *zone;
Linus Torvalds's avatar
Linus Torvalds committed
1106

1107 1108 1109 1110 1111
	for (zone = *zonep++; zone; zone = *zonep++) {
		unsigned long size = zone->present_pages;
		unsigned long high = zone->pages_high;
		if (size > high)
			sum += size - high;
Linus Torvalds's avatar
Linus Torvalds committed
1112 1113 1114 1115 1116 1117 1118 1119 1120 1121
	}

	return sum;
}

/*
 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
 */
unsigned int nr_free_buffer_pages(void)
{
Al Viro's avatar
Al Viro committed
1122
	return nr_free_zone_pages(gfp_zone(GFP_USER));
Linus Torvalds's avatar
Linus Torvalds committed
1123 1124 1125 1126 1127 1128 1129
}

/*
 * Amount of free RAM allocatable within all zones
 */
unsigned int nr_free_pagecache_pages(void)
{
Al Viro's avatar
Al Viro committed
1130
	return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER));
Linus Torvalds's avatar
Linus Torvalds committed
1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167
}

#ifdef CONFIG_HIGHMEM
unsigned int nr_free_highpages (void)
{
	pg_data_t *pgdat;
	unsigned int pages = 0;

	for_each_pgdat(pgdat)
		pages += pgdat->node_zones[ZONE_HIGHMEM].free_pages;

	return pages;
}
#endif

#ifdef CONFIG_NUMA
static void show_node(struct zone *zone)
{
	printk("Node %d ", zone->zone_pgdat->node_id);
}
#else
#define show_node(zone)	do { } while (0)
#endif

/*
 * Accumulate the page_state information across all CPUs.
 * The result is unavoidably approximate - it can change
 * during and after execution of this function.
 */
static DEFINE_PER_CPU(struct page_state, page_states) = {0};

atomic_t nr_pagecache = ATOMIC_INIT(0);
EXPORT_SYMBOL(nr_pagecache);
#ifdef CONFIG_SMP
DEFINE_PER_CPU(long, nr_pagecache_local) = 0;
#endif

Nick Piggin's avatar
Nick Piggin committed
1168
static void __get_page_state(struct page_state *ret, int nr, cpumask_t *cpumask)
Linus Torvalds's avatar
Linus Torvalds committed
1169 1170 1171 1172 1173
{
	int cpu = 0;

	memset(ret, 0, sizeof(*ret));

1174
	cpu = first_cpu(*cpumask);
Linus Torvalds's avatar
Linus Torvalds committed
1175 1176 1177 1178 1179
	while (cpu < NR_CPUS) {
		unsigned long *in, *out, off;

		in = (unsigned long *)&per_cpu(page_states, cpu);

1180
		cpu = next_cpu(cpu, *cpumask);
Linus Torvalds's avatar
Linus Torvalds committed
1181 1182 1183 1184 1185 1186 1187 1188 1189 1190

		if (cpu < NR_CPUS)
			prefetch(&per_cpu(page_states, cpu));

		out = (unsigned long *)ret;
		for (off = 0; off < nr; off++)
			*out++ += *in++;
	}
}

1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201
void get_page_state_node(struct page_state *ret, int node)
{
	int nr;
	cpumask_t mask = node_to_cpumask(node);

	nr = offsetof(struct page_state, GET_PAGE_STATE_LAST);
	nr /= sizeof(unsigned long);

	__get_page_state(ret, nr+1, &mask);
}

Linus Torvalds's avatar
Linus Torvalds committed
1202 1203 1204
void get_page_state(struct page_state *ret)
{
	int nr;
1205
	cpumask_t mask = CPU_MASK_ALL;
Linus Torvalds's avatar
Linus Torvalds committed
1206 1207 1208 1209

	nr = offsetof(struct page_state, GET_PAGE_STATE_LAST);
	nr /= sizeof(unsigned long);

1210
	__get_page_state(ret, nr + 1, &mask);
Linus Torvalds's avatar
Linus Torvalds committed
1211 1212 1213 1214
}

void get_full_page_state(struct page_state *ret)
{
1215 1216 1217
	cpumask_t mask = CPU_MASK_ALL;

	__get_page_state(ret, sizeof(*ret) / sizeof(unsigned long), &mask);
Linus Torvalds's avatar
Linus Torvalds committed
1218 1219
}

1220
unsigned long __read_page_state(unsigned long offset)
Linus Torvalds's avatar
Linus Torvalds committed
1221 1222 1223 1224
{
	unsigned long ret = 0;
	int cpu;

Nick Piggin's avatar
Nick Piggin committed
1225
	for_each_cpu(cpu) {
Linus Torvalds's avatar
Linus Torvalds committed
1226 1227 1228 1229 1230 1231 1232 1233
		unsigned long in;

		in = (unsigned long)&per_cpu(page_states, cpu) + offset;
		ret += *((unsigned long *)in);
	}
	return ret;
}

1234
void __mod_page_state(unsigned long offset, unsigned long delta)
Linus Torvalds's avatar
Linus Torvalds committed
1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336
{
	unsigned long flags;
	void* ptr;

	local_irq_save(flags);
	ptr = &__get_cpu_var(page_states);
	*(unsigned long*)(ptr + offset) += delta;
	local_irq_restore(flags);
}

EXPORT_SYMBOL(__mod_page_state);

void __get_zone_counts(unsigned long *active, unsigned long *inactive,
			unsigned long *free, struct pglist_data *pgdat)
{
	struct zone *zones = pgdat->node_zones;
	int i;

	*active = 0;
	*inactive = 0;
	*free = 0;
	for (i = 0; i < MAX_NR_ZONES; i++) {
		*active += zones[i].nr_active;
		*inactive += zones[i].nr_inactive;
		*free += zones[i].free_pages;
	}
}

void get_zone_counts(unsigned long *active,
		unsigned long *inactive, unsigned long *free)
{
	struct pglist_data *pgdat;

	*active = 0;
	*inactive = 0;
	*free = 0;
	for_each_pgdat(pgdat) {
		unsigned long l, m, n;
		__get_zone_counts(&l, &m, &n, pgdat);
		*active += l;
		*inactive += m;
		*free += n;
	}
}

void si_meminfo(struct sysinfo *val)
{
	val->totalram = totalram_pages;
	val->sharedram = 0;
	val->freeram = nr_free_pages();
	val->bufferram = nr_blockdev_pages();
#ifdef CONFIG_HIGHMEM
	val->totalhigh = totalhigh_pages;
	val->freehigh = nr_free_highpages();
#else
	val->totalhigh = 0;
	val->freehigh = 0;
#endif
	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);
	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
	val->freehigh = pgdat->node_zones[ZONE_HIGHMEM].free_pages;
	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)
{
	struct page_state ps;
	int cpu, temperature;
	unsigned long active;
	unsigned long inactive;
	unsigned long free;
	struct zone *zone;

	for_each_zone(zone) {
		show_node(zone);
		printk("%s per-cpu:", zone->name);

		if (!zone->present_pages) {
			printk(" empty\n");
			continue;
		} else
			printk("\n");

1337
		for_each_online_cpu(cpu) {
Linus Torvalds's avatar
Linus Torvalds committed
1338 1339
			struct per_cpu_pageset *pageset;

1340
			pageset = zone_pcp(zone, cpu);
Linus Torvalds's avatar
Linus Torvalds committed
1341 1342

			for (temperature = 0; temperature < 2; temperature++)
Nick Piggin's avatar
Nick Piggin committed
1343
				printk("cpu %d %s: high %d, batch %d used:%d\n",
Linus Torvalds's avatar
Linus Torvalds committed
1344 1345 1346
					cpu,
					temperature ? "cold" : "hot",
					pageset->pcp[temperature].high,
1347 1348
					pageset->pcp[temperature].batch,
					pageset->pcp[temperature].count);
Linus Torvalds's avatar
Linus Torvalds committed
1349 1350 1351 1352 1353 1354
		}
	}

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

Denis Vlasenko's avatar
Denis Vlasenko committed
1355
	printk("Free pages: %11ukB (%ukB HighMem)\n",
Linus Torvalds's avatar
Linus Torvalds committed
1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396