page_alloc.c 70.3 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 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>
L
Linus Torvalds 已提交
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>
L
Linus Torvalds 已提交
37 38
#include <linux/nodemask.h>
#include <linux/vmalloc.h>
39
#include <linux/mempolicy.h>
L
Linus Torvalds 已提交
40 41

#include <asm/tlbflush.h>
42
#include <asm/div64.h>
L
Linus Torvalds 已提交
43 44 45 46 47 48
#include "internal.h"

/*
 * MCD - HACK: Find somewhere to initialize this EARLY, or make this
 * initializer cleaner
 */
49
nodemask_t node_online_map __read_mostly = { { [0] = 1UL } };
50
EXPORT_SYMBOL(node_online_map);
51
nodemask_t node_possible_map __read_mostly = NODE_MASK_ALL;
52
EXPORT_SYMBOL(node_possible_map);
53 54
unsigned long totalram_pages __read_mostly;
unsigned long totalhigh_pages __read_mostly;
55
unsigned long totalreserve_pages __read_mostly;
L
Linus Torvalds 已提交
56
long nr_swap_pages;
57
int percpu_pagelist_fraction;
L
Linus Torvalds 已提交
58

59
static void __free_pages_ok(struct page *page, unsigned int order);
60

L
Linus Torvalds 已提交
61 62 63 64 65 66 67
/*
 * 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
68 69 70
 *
 * 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
71
 */
A
Andi Kleen 已提交
72
int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { 256, 256, 32 };
L
Linus Torvalds 已提交
73 74 75 76 77 78 79

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
 */
80
struct zone *zone_table[1 << ZONETABLE_SHIFT] __read_mostly;
L
Linus Torvalds 已提交
81 82
EXPORT_SYMBOL(zone_table);

A
Andi Kleen 已提交
83
static char *zone_names[MAX_NR_ZONES] = { "DMA", "DMA32", "Normal", "HighMem" };
L
Linus Torvalds 已提交
84 85 86 87 88
int min_free_kbytes = 1024;

unsigned long __initdata nr_kernel_pages;
unsigned long __initdata nr_all_pages;

N
Nick Piggin 已提交
89
#ifdef CONFIG_DEBUG_VM
90
static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
L
Linus Torvalds 已提交
91
{
92 93 94
	int ret = 0;
	unsigned seq;
	unsigned long pfn = page_to_pfn(page);
95

96 97 98 99 100 101 102 103 104
	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;
105 106 107 108
}

static int page_is_consistent(struct zone *zone, struct page *page)
{
L
Linus Torvalds 已提交
109 110
#ifdef CONFIG_HOLES_IN_ZONE
	if (!pfn_valid(page_to_pfn(page)))
111
		return 0;
L
Linus Torvalds 已提交
112 113
#endif
	if (zone != page_zone(page))
114 115 116 117 118 119 120 121 122 123
		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
124
		return 1;
125 126 127
	if (!page_is_consistent(zone, page))
		return 1;

L
Linus Torvalds 已提交
128 129 130
	return 0;
}

N
Nick Piggin 已提交
131 132 133 134 135 136 137
#else
static inline int bad_range(struct zone *zone, struct page *page)
{
	return 0;
}
#endif

N
Nick Piggin 已提交
138
static void bad_page(struct page *page)
L
Linus Torvalds 已提交
139
{
N
Nick Piggin 已提交
140
	printk(KERN_EMERG "Bad page state in process '%s'\n"
141 142 143
		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
144 145 146
		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
147
	dump_stack();
148 149
	page->flags &= ~(1 << PG_lru	|
			1 << PG_private |
L
Linus Torvalds 已提交
150 151 152
			1 << PG_locked	|
			1 << PG_active	|
			1 << PG_dirty	|
153 154
			1 << PG_reclaim |
			1 << PG_slab    |
L
Linus Torvalds 已提交
155
			1 << PG_swapcache |
156 157
			1 << PG_writeback |
			1 << PG_buddy );
L
Linus Torvalds 已提交
158 159 160
	set_page_count(page, 0);
	reset_page_mapcount(page);
	page->mapping = NULL;
161
	add_taint(TAINT_BAD_PAGE);
L
Linus Torvalds 已提交
162 163 164 165 166 167 168 169 170 171 172 173
}

/*
 * 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).
 *
174 175 176
 * 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
177
 */
178 179 180 181 182 183

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

L
Linus Torvalds 已提交
184 185 186 187 188
static void prep_compound_page(struct page *page, unsigned long order)
{
	int i;
	int nr_pages = 1 << order;

189
	page[1].lru.next = (void *)free_compound_page;	/* set dtor */
190
	page[1].lru.prev = (void *)order;
L
Linus Torvalds 已提交
191 192 193
	for (i = 0; i < nr_pages; i++) {
		struct page *p = page + i;

194
		__SetPageCompound(p);
H
Hugh Dickins 已提交
195
		set_page_private(p, (unsigned long)page);
L
Linus Torvalds 已提交
196 197 198 199 200 201 202 203
	}
}

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

204
	if (unlikely((unsigned long)page[1].lru.prev != order))
N
Nick Piggin 已提交
205
		bad_page(page);
L
Linus Torvalds 已提交
206 207 208 209

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

N
Nick Piggin 已提交
210 211 212
		if (unlikely(!PageCompound(p) |
				(page_private(p) != (unsigned long)page)))
			bad_page(page);
213
		__ClearPageCompound(p);
L
Linus Torvalds 已提交
214 215 216
	}
}

N
Nick Piggin 已提交
217 218 219 220 221
static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
{
	int i;

	BUG_ON((gfp_flags & (__GFP_WAIT | __GFP_HIGHMEM)) == __GFP_HIGHMEM);
222 223 224 225 226
	/*
	 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
	 * and __GFP_HIGHMEM from hard or soft interrupt context.
	 */
	BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt());
N
Nick Piggin 已提交
227 228 229 230
	for (i = 0; i < (1 << order); i++)
		clear_highpage(page + i);
}

L
Linus Torvalds 已提交
231 232 233 234 235
/*
 * 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.
 */
236 237
static inline unsigned long page_order(struct page *page)
{
H
Hugh Dickins 已提交
238
	return page_private(page);
L
Linus Torvalds 已提交
239 240
}

241 242
static inline void set_page_order(struct page *page, int order)
{
H
Hugh Dickins 已提交
243
	set_page_private(page, order);
244
	__SetPageBuddy(page);
L
Linus Torvalds 已提交
245 246 247 248
}

static inline void rmv_page_order(struct page *page)
{
249
	__ClearPageBuddy(page);
H
Hugh Dickins 已提交
250
	set_page_private(page, 0);
L
Linus Torvalds 已提交
251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286
}

/*
 * 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
N
Nick Piggin 已提交
287
 * (a) the buddy is not in a hole &&
288
 * (b) the buddy is in the buddy system &&
289 290
 * (c) a page and its buddy have the same order &&
 * (d) a page and its buddy are in the same zone.
291 292 293
 *
 * 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
294
 *
295
 * For recording page's order, we use page_private(page).
L
Linus Torvalds 已提交
296
 */
297 298
static inline int page_is_buddy(struct page *page, struct page *buddy,
								int order)
L
Linus Torvalds 已提交
299
{
N
Nick Piggin 已提交
300
#ifdef CONFIG_HOLES_IN_ZONE
301
	if (!pfn_valid(page_to_pfn(buddy)))
N
Nick Piggin 已提交
302 303 304
		return 0;
#endif

305 306 307 308 309
	if (page_zone_id(page) != page_zone_id(buddy))
		return 0;

	if (PageBuddy(buddy) && page_order(buddy) == order) {
		BUG_ON(page_count(buddy) != 0);
310
		return 1;
311
	}
312
	return 0;
L
Linus Torvalds 已提交
313 314 315 316 317 318 319 320 321 322 323 324 325 326 327
}

/*
 * 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
328
 * free pages of length of (1 << order) and marked with PG_buddy. Page's
H
Hugh Dickins 已提交
329
 * order is recorded in page_private(page) field.
L
Linus Torvalds 已提交
330 331 332 333 334 335 336 337 338
 * 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
339
static inline void __free_one_page(struct page *page,
L
Linus Torvalds 已提交
340 341 342 343 344
		struct zone *zone, unsigned int order)
{
	unsigned long page_idx;
	int order_size = 1 << order;

N
Nick Piggin 已提交
345
	if (unlikely(PageCompound(page)))
L
Linus Torvalds 已提交
346 347 348 349 350 351 352 353 354 355 356 357 358 359
		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);
360
		if (!page_is_buddy(page, buddy, order))
L
Linus Torvalds 已提交
361
			break;		/* Move the buddy up one level. */
N
Nick Piggin 已提交
362

L
Linus Torvalds 已提交
363 364 365 366
		list_del(&buddy->lru);
		area = zone->free_area + order;
		area->nr_free--;
		rmv_page_order(buddy);
N
Nick Piggin 已提交
367
		combined_idx = __find_combined_index(page_idx, order);
L
Linus Torvalds 已提交
368 369 370 371 372 373 374 375 376
		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
377
static inline int free_pages_check(struct page *page)
L
Linus Torvalds 已提交
378
{
N
Nick Piggin 已提交
379 380 381
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
		(page_count(page) != 0)  |
L
Linus Torvalds 已提交
382 383 384 385 386 387 388 389
		(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
390
			1 << PG_writeback |
391 392
			1 << PG_reserved |
			1 << PG_buddy ))))
N
Nick Piggin 已提交
393
		bad_page(page);
L
Linus Torvalds 已提交
394
	if (PageDirty(page))
N
Nick Piggin 已提交
395
		__ClearPageDirty(page);
396 397 398 399 400 401
	/*
	 * 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
402 403 404 405 406
}

/*
 * Frees a list of pages. 
 * Assumes all pages on list are in same zone, and of same order.
407
 * count is the number of pages to free.
L
Linus Torvalds 已提交
408 409 410 411 412 413 414
 *
 * 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
415 416
static void free_pages_bulk(struct zone *zone, int count,
					struct list_head *list, int order)
L
Linus Torvalds 已提交
417
{
N
Nick Piggin 已提交
418
	spin_lock(&zone->lock);
L
Linus Torvalds 已提交
419 420
	zone->all_unreclaimable = 0;
	zone->pages_scanned = 0;
N
Nick Piggin 已提交
421 422 423 424
	while (count--) {
		struct page *page;

		BUG_ON(list_empty(list));
L
Linus Torvalds 已提交
425
		page = list_entry(list->prev, struct page, lru);
N
Nick Piggin 已提交
426
		/* have to delete it as __free_one_page list manipulates */
L
Linus Torvalds 已提交
427
		list_del(&page->lru);
N
Nick Piggin 已提交
428
		__free_one_page(page, zone, order);
L
Linus Torvalds 已提交
429
	}
N
Nick Piggin 已提交
430
	spin_unlock(&zone->lock);
L
Linus Torvalds 已提交
431 432
}

N
Nick Piggin 已提交
433
static void free_one_page(struct zone *zone, struct page *page, int order)
L
Linus Torvalds 已提交
434 435
{
	LIST_HEAD(list);
N
Nick Piggin 已提交
436 437 438 439 440 441 442
	list_add(&page->lru, &list);
	free_pages_bulk(zone, 1, &list, order);
}

static void __free_pages_ok(struct page *page, unsigned int order)
{
	unsigned long flags;
L
Linus Torvalds 已提交
443
	int i;
444
	int reserved = 0;
L
Linus Torvalds 已提交
445 446

	arch_free_page(page, order);
447 448
	if (!PageHighMem(page))
		mutex_debug_check_no_locks_freed(page_address(page),
449
						 PAGE_SIZE<<order);
L
Linus Torvalds 已提交
450 451

	for (i = 0 ; i < (1 << order) ; ++i)
N
Nick Piggin 已提交
452
		reserved += free_pages_check(page + i);
453 454 455
	if (reserved)
		return;

N
Nick Piggin 已提交
456
	kernel_map_pages(page, 1 << order, 0);
N
Nick Piggin 已提交
457
	local_irq_save(flags);
N
Nick Piggin 已提交
458
	__mod_page_state(pgfree, 1 << order);
N
Nick Piggin 已提交
459
	free_one_page(page_zone(page), page, order);
N
Nick Piggin 已提交
460
	local_irq_restore(flags);
L
Linus Torvalds 已提交
461 462
}

463 464 465 466 467 468 469 470
/*
 * 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);
471
		set_page_refcounted(page);
N
Nick Piggin 已提交
472
		__free_page(page);
473 474 475
	} else {
		int loop;

N
Nick Piggin 已提交
476
		prefetchw(page);
477 478 479
		for (loop = 0; loop < BITS_PER_LONG; loop++) {
			struct page *p = &page[loop];

N
Nick Piggin 已提交
480 481
			if (loop + 1 < BITS_PER_LONG)
				prefetchw(p + 1);
482 483 484 485
			__ClearPageReserved(p);
			set_page_count(p, 0);
		}

486
		set_page_refcounted(page);
N
Nick Piggin 已提交
487
		__free_pages(page, order);
488 489 490
	}
}

L
Linus Torvalds 已提交
491 492 493 494 495 496 497 498 499 500 501 502 503 504 505

/*
 * 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
506
static inline void expand(struct zone *zone, struct page *page,
L
Linus Torvalds 已提交
507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524
 	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
 */
N
Nick Piggin 已提交
525
static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
L
Linus Torvalds 已提交
526
{
N
Nick Piggin 已提交
527 528 529
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
		(page_count(page) != 0)  |
530 531
		(page->flags & (
			1 << PG_lru	|
L
Linus Torvalds 已提交
532 533 534 535 536
			1 << PG_private	|
			1 << PG_locked	|
			1 << PG_active	|
			1 << PG_dirty	|
			1 << PG_reclaim	|
537
			1 << PG_slab    |
L
Linus Torvalds 已提交
538
			1 << PG_swapcache |
N
Nick Piggin 已提交
539
			1 << PG_writeback |
540 541
			1 << PG_reserved |
			1 << PG_buddy ))))
N
Nick Piggin 已提交
542
		bad_page(page);
L
Linus Torvalds 已提交
543

544 545 546 547 548 549 550
	/*
	 * 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
551 552 553
	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
554
	set_page_private(page, 0);
555
	set_page_refcounted(page);
L
Linus Torvalds 已提交
556
	kernel_map_pages(page, 1 << order, 1);
N
Nick Piggin 已提交
557 558 559 560 561 562 563

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

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

564
	return 0;
L
Linus Torvalds 已提交
565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586
}

/* 
 * 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
587 588
		expand(zone, page, order, current_order, area);
		return page;
L
Linus Torvalds 已提交
589 590 591 592 593 594 595 596 597 598 599 600 601 602 603
	}

	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
604
	spin_lock(&zone->lock);
L
Linus Torvalds 已提交
605
	for (i = 0; i < count; ++i) {
N
Nick Piggin 已提交
606 607
		struct page *page = __rmqueue(zone, order);
		if (unlikely(page == NULL))
L
Linus Torvalds 已提交
608 609 610
			break;
		list_add_tail(&page->lru, list);
	}
N
Nick Piggin 已提交
611
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
612
	return i;
L
Linus Torvalds 已提交
613 614
}

615
#ifdef CONFIG_NUMA
616 617 618
/*
 * Called from the slab reaper to drain pagesets on a particular node that
 * belong to the currently executing processor.
619 620
 * Note that this function must be called with the thread pinned to
 * a single processor.
621 622
 */
void drain_node_pages(int nodeid)
623
{
624
	int i, z;
625 626
	unsigned long flags;

627 628
	for (z = 0; z < MAX_NR_ZONES; z++) {
		struct zone *zone = NODE_DATA(nodeid)->node_zones + z;
629 630
		struct per_cpu_pageset *pset;

N
Nick Piggin 已提交
631
		pset = zone_pcp(zone, smp_processor_id());
632 633 634 635
		for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) {
			struct per_cpu_pages *pcp;

			pcp = &pset->pcp[i];
636 637 638 639 640 641
			if (pcp->count) {
				local_irq_save(flags);
				free_pages_bulk(zone, pcp->count, &pcp->list, 0);
				pcp->count = 0;
				local_irq_restore(flags);
			}
642 643 644 645 646
		}
	}
}
#endif

L
Linus Torvalds 已提交
647 648 649
#if defined(CONFIG_PM) || defined(CONFIG_HOTPLUG_CPU)
static void __drain_pages(unsigned int cpu)
{
N
Nick Piggin 已提交
650
	unsigned long flags;
L
Linus Torvalds 已提交
651 652 653 654 655 656
	struct zone *zone;
	int i;

	for_each_zone(zone) {
		struct per_cpu_pageset *pset;

657
		pset = zone_pcp(zone, cpu);
L
Linus Torvalds 已提交
658 659 660 661
		for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) {
			struct per_cpu_pages *pcp;

			pcp = &pset->pcp[i];
N
Nick Piggin 已提交
662
			local_irq_save(flags);
N
Nick Piggin 已提交
663 664
			free_pages_bulk(zone, pcp->count, &pcp->list, 0);
			pcp->count = 0;
N
Nick Piggin 已提交
665
			local_irq_restore(flags);
L
Linus Torvalds 已提交
666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710
		}
	}
}
#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 */

N
Nick Piggin 已提交
711
static void zone_statistics(struct zonelist *zonelist, struct zone *z, int cpu)
L
Linus Torvalds 已提交
712 713 714 715 716 717
{
#ifdef CONFIG_NUMA
	pg_data_t *pg = z->zone_pgdat;
	pg_data_t *orig = zonelist->zones[0]->zone_pgdat;
	struct per_cpu_pageset *p;

N
Nick Piggin 已提交
718
	p = zone_pcp(z, cpu);
L
Linus Torvalds 已提交
719
	if (pg == orig) {
720
		p->numa_hit++;
L
Linus Torvalds 已提交
721 722
	} else {
		p->numa_miss++;
723
		zone_pcp(zonelist->zones[0], cpu)->numa_foreign++;
L
Linus Torvalds 已提交
724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744
	}
	if (pg == NODE_DATA(numa_node_id()))
		p->local_node++;
	else
		p->other_node++;
#endif
}

/*
 * 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;

	arch_free_page(page, 0);

	if (PageAnon(page))
		page->mapping = NULL;
N
Nick Piggin 已提交
745
	if (free_pages_check(page))
746 747 748 749
		return;

	kernel_map_pages(page, 1, 0);

750
	pcp = &zone_pcp(zone, get_cpu())->pcp[cold];
L
Linus Torvalds 已提交
751
	local_irq_save(flags);
N
Nick Piggin 已提交
752
	__inc_page_state(pgfree);
L
Linus Torvalds 已提交
753 754
	list_add(&page->lru, &pcp->list);
	pcp->count++;
N
Nick Piggin 已提交
755 756 757 758
	if (pcp->count >= pcp->high) {
		free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
		pcp->count -= pcp->batch;
	}
L
Linus Torvalds 已提交
759 760 761 762 763 764 765 766 767 768 769 770 771 772
	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
773 774 775 776 777 778 779 780 781 782 783 784 785 786
/*
 * 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;

	BUG_ON(PageCompound(page));
	BUG_ON(!page_count(page));
787 788
	for (i = 1; i < (1 << order); i++)
		set_page_refcounted(page + i);
N
Nick Piggin 已提交
789 790
}

L
Linus Torvalds 已提交
791 792 793 794 795
/*
 * 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
796 797
static struct page *buffered_rmqueue(struct zonelist *zonelist,
			struct zone *zone, int order, gfp_t gfp_flags)
L
Linus Torvalds 已提交
798 799
{
	unsigned long flags;
800
	struct page *page;
L
Linus Torvalds 已提交
801
	int cold = !!(gfp_flags & __GFP_COLD);
N
Nick Piggin 已提交
802
	int cpu;
L
Linus Torvalds 已提交
803

804
again:
N
Nick Piggin 已提交
805
	cpu  = get_cpu();
N
Nick Piggin 已提交
806
	if (likely(order == 0)) {
L
Linus Torvalds 已提交
807 808
		struct per_cpu_pages *pcp;

N
Nick Piggin 已提交
809
		pcp = &zone_pcp(zone, cpu)->pcp[cold];
L
Linus Torvalds 已提交
810
		local_irq_save(flags);
N
Nick Piggin 已提交
811
		if (!pcp->count) {
L
Linus Torvalds 已提交
812 813
			pcp->count += rmqueue_bulk(zone, 0,
						pcp->batch, &pcp->list);
N
Nick Piggin 已提交
814 815
			if (unlikely(!pcp->count))
				goto failed;
L
Linus Torvalds 已提交
816
		}
N
Nick Piggin 已提交
817 818 819
		page = list_entry(pcp->list.next, struct page, lru);
		list_del(&page->lru);
		pcp->count--;
R
Rohit Seth 已提交
820
	} else {
L
Linus Torvalds 已提交
821 822
		spin_lock_irqsave(&zone->lock, flags);
		page = __rmqueue(zone, order);
N
Nick Piggin 已提交
823 824 825
		spin_unlock(&zone->lock);
		if (!page)
			goto failed;
L
Linus Torvalds 已提交
826 827
	}

N
Nick Piggin 已提交
828 829 830 831
	__mod_page_state_zone(zone, pgalloc, 1 << order);
	zone_statistics(zonelist, zone, cpu);
	local_irq_restore(flags);
	put_cpu();
L
Linus Torvalds 已提交
832

N
Nick Piggin 已提交
833
	BUG_ON(bad_range(zone, page));
N
Nick Piggin 已提交
834
	if (prep_new_page(page, order, gfp_flags))
N
Nick Piggin 已提交
835
		goto again;
L
Linus Torvalds 已提交
836
	return page;
N
Nick Piggin 已提交
837 838 839 840 841

failed:
	local_irq_restore(flags);
	put_cpu();
	return NULL;
L
Linus Torvalds 已提交
842 843
}

R
Rohit Seth 已提交
844
#define ALLOC_NO_WATERMARKS	0x01 /* don't check watermarks at all */
845 846 847 848 849 850
#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
851

L
Linus Torvalds 已提交
852 853 854 855 856
/*
 * 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
857
		      int classzone_idx, int alloc_flags)
L
Linus Torvalds 已提交
858 859 860 861 862
{
	/* free_pages my go negative - that's OK */
	long min = mark, free_pages = z->free_pages - (1 << order) + 1;
	int o;

R
Rohit Seth 已提交
863
	if (alloc_flags & ALLOC_HIGH)
L
Linus Torvalds 已提交
864
		min -= min / 2;
R
Rohit Seth 已提交
865
	if (alloc_flags & ALLOC_HARDER)
L
Linus Torvalds 已提交
866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882
		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;
}

R
Rohit Seth 已提交
883 884 885 886 887 888 889
/*
 * 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)
M
Martin Hicks 已提交
890
{
R
Rohit Seth 已提交
891 892 893 894 895 896 897 898 899 900 901 902 903 904
	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)) {
905 906 907 908 909 910 911 912
			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,
R
Rohit Seth 已提交
913
				    classzone_idx, alloc_flags))
914 915 916
				if (!zone_reclaim_mode ||
				    !zone_reclaim(*z, gfp_mask, order))
					continue;
R
Rohit Seth 已提交
917 918
		}

N
Nick Piggin 已提交
919
		page = buffered_rmqueue(zonelist, *z, order, gfp_mask);
R
Rohit Seth 已提交
920 921 922 923 924
		if (page) {
			break;
		}
	} while (*(++z) != NULL);
	return page;
M
Martin Hicks 已提交
925 926
}

L
Linus Torvalds 已提交
927 928 929 930
/*
 * This is the 'heart' of the zoned buddy allocator.
 */
struct page * fastcall
A
Al Viro 已提交
931
__alloc_pages(gfp_t gfp_mask, unsigned int order,
L
Linus Torvalds 已提交
932 933
		struct zonelist *zonelist)
{
A
Al Viro 已提交
934
	const gfp_t wait = gfp_mask & __GFP_WAIT;
R
Rohit Seth 已提交
935
	struct zone **z;
L
Linus Torvalds 已提交
936 937 938 939
	struct page *page;
	struct reclaim_state reclaim_state;
	struct task_struct *p = current;
	int do_retry;
R
Rohit Seth 已提交
940
	int alloc_flags;
L
Linus Torvalds 已提交
941 942 943 944
	int did_some_progress;

	might_sleep_if(wait);

945
restart:
R
Rohit Seth 已提交
946
	z = zonelist->zones;  /* the list of zones suitable for gfp_mask */
L
Linus Torvalds 已提交
947

R
Rohit Seth 已提交
948
	if (unlikely(*z == NULL)) {
L
Linus Torvalds 已提交
949 950 951
		/* Should this ever happen?? */
		return NULL;
	}
952

R
Rohit Seth 已提交
953
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order,
954
				zonelist, ALLOC_WMARK_LOW|ALLOC_CPUSET);
R
Rohit Seth 已提交
955 956
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
957

958
	do {
959
		if (cpuset_zone_allowed(*z, gfp_mask|__GFP_HARDWALL))
960
			wakeup_kswapd(*z, order);
961
	} while (*(++z));
L
Linus Torvalds 已提交
962

963
	/*
R
Rohit Seth 已提交
964 965 966 967 968 969
	 * 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
970 971
	 * policy or is asking for __GFP_HIGH memory.  GFP_ATOMIC requests will
	 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
972
	 */
973
	alloc_flags = ALLOC_WMARK_MIN;
R
Rohit Seth 已提交
974 975 976 977
	if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait)
		alloc_flags |= ALLOC_HARDER;
	if (gfp_mask & __GFP_HIGH)
		alloc_flags |= ALLOC_HIGH;
978 979
	if (wait)
		alloc_flags |= ALLOC_CPUSET;
L
Linus Torvalds 已提交
980 981 982

	/*
	 * Go through the zonelist again. Let __GFP_HIGH and allocations
R
Rohit Seth 已提交
983
	 * coming from realtime tasks go deeper into reserves.
L
Linus Torvalds 已提交
984 985 986
	 *
	 * This is the last chance, in general, before the goto nopage.
	 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
987
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
L
Linus Torvalds 已提交
988
	 */
R
Rohit Seth 已提交
989 990 991
	page = get_page_from_freelist(gfp_mask, order, zonelist, alloc_flags);
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
992 993

	/* This allocation should allow future memory freeing. */
994 995 996 997

	if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE)))
			&& !in_interrupt()) {
		if (!(gfp_mask & __GFP_NOMEMALLOC)) {
K
Kirill Korotaev 已提交
998
nofail_alloc:
999
			/* go through the zonelist yet again, ignoring mins */
R
Rohit Seth 已提交
1000
			page = get_page_from_freelist(gfp_mask, order,
1001
				zonelist, ALLOC_NO_WATERMARKS);
R
Rohit Seth 已提交
1002 1003
			if (page)
				goto got_pg;
K
Kirill Korotaev 已提交
1004 1005 1006 1007
			if (gfp_mask & __GFP_NOFAIL) {
				blk_congestion_wait(WRITE, HZ/50);
				goto nofail_alloc;
			}
L
Linus Torvalds 已提交
1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019
		}
		goto nopage;
	}

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

rebalance:
	cond_resched();

	/* We now go into synchronous reclaim */
1020
	cpuset_memory_pressure_bump();
L
Linus Torvalds 已提交
1021 1022 1023 1024
	p->flags |= PF_MEMALLOC;
	reclaim_state.reclaimed_slab = 0;
	p->reclaim_state = &reclaim_state;

R
Rohit Seth 已提交
1025
	did_some_progress = try_to_free_pages(zonelist->zones, gfp_mask);
L
Linus Torvalds 已提交
1026 1027 1028 1029 1030 1031 1032

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

	cond_resched();

	if (likely(did_some_progress)) {
R
Rohit Seth 已提交
1033 1034 1035 1036
		page = get_page_from_freelist(gfp_mask, order,
						zonelist, alloc_flags);
		if (page)
			goto got_pg;
L
Linus Torvalds 已提交
1037 1038 1039 1040 1041 1042 1043
	} 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
1044
		page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order,
1045
				zonelist, ALLOC_WMARK_HIGH|ALLOC_CPUSET);
R
Rohit Seth 已提交
1046 1047
		if (page)
			goto got_pg;
L
Linus Torvalds 已提交
1048

1049
		out_of_memory(zonelist, gfp_mask, order);
L
Linus Torvalds 已提交
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
		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();
J
Janet Morgan 已提交
1078
		show_mem();
L
Linus Torvalds 已提交
1079 1080 1081 1082 1083 1084 1085 1086 1087 1088
	}
got_pg:
	return page;
}

EXPORT_SYMBOL(__alloc_pages);

/*
 * Common helper functions.
 */
A
Al Viro 已提交
1089
fastcall unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
L
Linus Torvalds 已提交
1090 1091 1092 1093 1094 1095 1096 1097 1098 1099
{
	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
1100
fastcall unsigned long get_zeroed_page(gfp_t gfp_mask)
L
Linus Torvalds 已提交
1101 1102 1103 1104 1105 1106 1107
{
	struct page * page;

	/*
	 * get_zeroed_page() returns a 32-bit address, which cannot represent
	 * a highmem page
	 */
A
Al Viro 已提交
1108
	BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
L
Linus Torvalds 已提交
1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127

	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
1128
	if (put_page_testzero(page)) {
L
Linus Torvalds 已提交
1129 1130 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 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177
		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)
{
1178 1179
	/* Just pick one node, since fallback list is circular */
	pg_data_t *pgdat = NODE_DATA(numa_node_id());
L
Linus Torvalds 已提交
1180 1181
	unsigned int sum = 0;

1182 1183 1184
	struct zonelist *zonelist = pgdat->node_zonelists + offset;
	struct zone **zonep = zonelist->zones;
	struct zone *zone;
L
Linus Torvalds 已提交
1185

1186 1187 1188 1189 1190
	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
1191 1192 1193 1194 1195 1196 1197 1198 1199 1200
	}

	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
1201
	return nr_free_zone_pages(gfp_zone(GFP_USER));
L
Linus Torvalds 已提交
1202 1203 1204 1205 1206 1207 1208
}

/*
 * Amount of free RAM allocatable within all zones
 */
unsigned int nr_free_pagecache_pages(void)
{
A
Al Viro 已提交
1209
	return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER));
L
Linus Torvalds 已提交
1210 1211 1212 1213 1214 1215 1216 1217
}

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

1218
	for_each_online_pgdat(pgdat)
L
Linus Torvalds 已提交
1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246
		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

N
Nick Piggin 已提交
1247
static void __get_page_state(struct page_state *ret, int nr, cpumask_t *cpumask)
L
Linus Torvalds 已提交
1248
{
1249
	unsigned cpu;
L
Linus Torvalds 已提交
1250

1251
	memset(ret, 0, nr * sizeof(unsigned long));
1252
	cpus_and(*cpumask, *cpumask, cpu_online_map);
L
Linus Torvalds 已提交
1253

1254 1255 1256 1257 1258
	for_each_cpu_mask(cpu, *cpumask) {
		unsigned long *in;
		unsigned long *out;
		unsigned off;
		unsigned next_cpu;
1259

L
Linus Torvalds 已提交
1260 1261
		in = (unsigned long *)&per_cpu(page_states, cpu);

1262 1263 1264
		next_cpu = next_cpu(cpu, *cpumask);
		if (likely(next_cpu < NR_CPUS))
			prefetch(&per_cpu(page_states, next_cpu));
L
Linus Torvalds 已提交
1265 1266 1267 1268 1269 1270 1271

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

1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282
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);
}

L
Linus Torvalds 已提交
1283 1284 1285
void get_page_state(struct page_state *ret)
{
	int nr;
1286
	cpumask_t mask = CPU_MASK_ALL;
L
Linus Torvalds 已提交
1287 1288 1289 1290

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

1291
	__get_page_state(ret, nr + 1, &mask);
L
Linus Torvalds 已提交
1292 1293 1294 1295
}

void get_full_page_state(struct page_state *ret)
{
1296 1297 1298
	cpumask_t mask = CPU_MASK_ALL;

	__get_page_state(ret, sizeof(*ret) / sizeof(unsigned long), &mask);
L
Linus Torvalds 已提交
1299 1300
}

N
Nick Piggin 已提交
1301
unsigned long read_page_state_offset(unsigned long offset)
L
Linus Torvalds 已提交
1302 1303 1304 1305
{
	unsigned long ret = 0;
	int cpu;

1306
	for_each_online_cpu(cpu) {
L
Linus Torvalds 已提交
1307 1308 1309 1310 1311 1312 1313 1314
		unsigned long in;

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

N
Nick Piggin 已提交
1315 1316 1317 1318 1319 1320 1321 1322 1323 1324
void __mod_page_state_offset(unsigned long offset, unsigned long delta)
{
	void *ptr;

	ptr = &__get_cpu_var(page_states);
	*(unsigned long *)(ptr + offset) += delta;
}
EXPORT_SYMBOL(__mod_page_state_offset);

void mod_page_state_offset(unsigned long offset, unsigned long delta)
L
Linus Torvalds 已提交
1325 1326
{
	unsigned long flags;
N
Nick Piggin 已提交
1327
	void *ptr;
L
Linus Torvalds 已提交
1328 1329 1330

	local_irq_save(flags);
	ptr = &__get_cpu_var(page_states);
N
Nick Piggin 已提交
1331
	*(unsigned long *)(ptr + offset) += delta;
L
Linus Torvalds 已提交
1332 1333
	local_irq_restore(flags);
}
N
Nick Piggin 已提交
1334
EXPORT_SYMBOL(mod_page_state_offset);
L
Linus Torvalds 已提交
1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359

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;
1360
	for_each_online_pgdat(pgdat) {
L
Linus Torvalds 已提交
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 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419
		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);

1420
		if (!populated_zone(zone)) {
L
Linus Torvalds 已提交
1421 1422 1423 1424 1425
			printk(" empty\n");
			continue;
		} else
			printk("\n");

1426
		for_each_online_cpu(cpu) {
L
Linus Torvalds 已提交
1427 1428
			struct per_cpu_pageset *pageset;

1429
			pageset = zone_pcp(zone, cpu);
L
Linus Torvalds 已提交
1430 1431

			for (temperature = 0; temperature < 2; temperature++)
N
Nick Piggin 已提交
1432
				printk("cpu %d %s: high %d, batch %d used:%d\n",
L
Linus Torvalds 已提交
1433 1434 1435
					cpu,
					temperature ? "cold" : "hot",
					pageset->pcp[temperature].high,
1436 1437
					pageset->pcp[temperature].batch,
					pageset->pcp[temperature].count);
L
Linus Torvalds 已提交
1438 1439 1440 1441 1442 1443
		}
	}

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

D
Denis Vlasenko 已提交
1444
	printk("Free pages: %11ukB (%ukB HighMem)\n",
L
Linus Torvalds 已提交
1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496
		K(nr_free_pages()),
		K(nr_free_highpages()));

	printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu "
		"unstable:%lu free:%u slab:%lu mapped:%lu pagetables:%lu\n",
		active,
		inactive,
		ps.nr_dirty,
		ps.nr_writeback,
		ps.nr_unstable,
		nr_free_pages(),
		ps.nr_slab,
		ps.nr_mapped,
		ps.nr_page_table_pages);

	for_each_zone(zone) {
		int i;

		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) {
 		unsigned long nr, flags, order, total = 0;

		show_node(zone);
		printk("%s: ", zone->name);
1497
		if (!populated_zone(zone)) {
L
Linus Torvalds 已提交
1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516
			printk("empty\n");
			continue;
		}

		spin_lock_irqsave(&zone->lock, flags);
		for (order = 0; order < MAX_ORDER; order++) {
			nr = zone->free_area[order].nr_free;
			total += nr << order;
			printk("%lu*%lukB ", nr, K(1UL) << order);
		}
		spin_unlock_irqrestore(&zone->lock, flags);
		printk("= %lukB\n", K(total));
	}

	show_swap_cache_info();
}

/*
 * Builds allocation fallback zone lists.
1517 1518
 *
 * Add all populated zones of a node to the zonelist.
L
Linus Torvalds 已提交
1519
 */
1520
static int __init build_zonelists_node(pg_data_t *pgdat,
1521
			struct zonelist *zonelist, int nr_zones, int zone_type)
L
Linus Torvalds 已提交
1522
{
1523 1524
	struct zone *zone;

1525
	BUG_ON(zone_type > ZONE_HIGHMEM);
1526 1527

	do {
1528
		zone = pgdat->node_zones + zone_type;
1529
		if (populated_zone(zone)) {
L
Linus Torvalds 已提交
1530
#ifndef CONFIG_HIGHMEM
1531
			BUG_ON(zone_type > ZONE_NORMAL);
L
Linus Torvalds 已提交
1532
#endif
1533 1534
			zonelist->zones[nr_zones++] = zone;
			check_highest_zone(zone_type);
L
Linus Torvalds 已提交
1535
		}
1536
		zone_type--;
1537

1538 1539
	} while (zone_type >= 0);
	return nr_zones;
L
Linus Torvalds 已提交
1540 1541
}

A
Al Viro 已提交
1542 1543 1544 1545 1546
static inline int highest_zone(int zone_bits)
{
	int res = ZONE_NORMAL;
	if (zone_bits & (__force int)__GFP_HIGHMEM)
		res = ZONE_HIGHMEM;
A
Andi Kleen 已提交
1547 1548
	if (zone_bits & (__force int)__GFP_DMA32)
		res = ZONE_DMA32;
A
Al Viro 已提交
1549 1550 1551 1552 1553
	if (zone_bits & (__force int)__GFP_DMA)
		res = ZONE_DMA;
	return res;
}

L
Linus Torvalds 已提交
1554 1555 1556 1557
#ifdef CONFIG_NUMA
#define MAX_NODE_LOAD (num_online_nodes())
static int __initdata node_load[MAX_NUMNODES];
/**
1558
 * find_next_best_node - find the next node that should appear in a given node's fallback list
L
Linus Torvalds 已提交
1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572
 * @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.
 */
static int __init find_next_best_node(int node, nodemask_t *used_node_mask)
{
1573
	int n, val;
L
Linus Torvalds 已提交
1574 1575 1576
	int min_val = INT_MAX;
	int best_node = -1;

1577 1578 1579 1580 1581
	/* 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
1582

1583 1584
	for_each_online_node(n) {
		cpumask_t tmp;
L
Linus Torvalds 已提交
1585 1586 1587 1588 1589 1590 1591 1592

		/* 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);

1593 1594 1595
		/* Penalize nodes under us ("prefer the next node") */
		val += (n < node);

L
Linus Torvalds 已提交
1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635
		/* 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;
}

static void __init build_zonelists(pg_data_t *pgdat)
{
	int i, j, k, node, local_node;
	int prev_node, load;
	struct zonelist *zonelist;
	nodemask_t used_mask;

	/* initialize zonelists */
	for (i = 0; i < GFP_ZONETYPES; i++) {
		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) {
1636 1637 1638 1639 1640 1641 1642 1643 1644
		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
1645 1646 1647 1648 1649
		/*
		 * 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.
		 */
1650 1651

		if (distance != node_distance(local_node, prev_node))
L
Linus Torvalds 已提交
1652 1653 1654 1655 1656 1657 1658
			node_load[node] += load;
		prev_node = node;
		load--;
		for (i = 0; i < GFP_ZONETYPES; i++) {
			zonelist = pgdat->node_zonelists + i;
			for (j = 0; zonelist->zones[j] != NULL; j++);

A
Al Viro 已提交
1659
			k = highest_zone(i);
L
Linus Torvalds 已提交
1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679

	 		j = build_zonelists_node(NODE_DATA(node), zonelist, j, k);
			zonelist->zones[j] = NULL;
		}
	}
}

#else	/* CONFIG_NUMA */

static void __init build_zonelists(pg_data_t *pgdat)
{
	int i, j, k, node, local_node;

	local_node = pgdat->node_id;
	for (i = 0; i < GFP_ZONETYPES; i++) {
		struct zonelist *zonelist;

		zonelist = pgdat->node_zonelists + i;

		j = 0;
A
Al Viro 已提交
1680
		k = highest_zone(i);
L
Linus Torvalds 已提交
1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729
 		j = build_zonelists_node(pgdat, zonelist, j, k);
 		/*
 		 * Now we build the zonelist so that it contains the zones
 		 * of all the other nodes.
 		 * We don't want to pressure a particular node, so when
 		 * building the zones for node N, we make sure that the
 		 * zones coming right after the local ones are those from
 		 * node N+1 (modulo N)
 		 */
		for (node = local_node + 1; node < MAX_NUMNODES; node++) {
			if (!node_online(node))
				continue;
			j = build_zonelists_node(NODE_DATA(node), zonelist, j, k);
		}
		for (node = 0; node < local_node; node++) {
			if (!node_online(node))
				continue;
			j = build_zonelists_node(NODE_DATA(node), zonelist, j, k);
		}

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

#endif	/* CONFIG_NUMA */

void __init build_all_zonelists(void)
{
	int i;

	for_each_online_node(i)
		build_zonelists(NODE_DATA(i));
	printk("Built %i zonelists\n", num_online_nodes());
	cpuset_init_current_mems_allowed();
}

/*
 * 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

1730
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
L
Linus Torvalds 已提交
1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784
{
	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);
}

/*
 * 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))

static void __init calculate_zone_totalpages(struct pglist_data *pgdat,
		unsigned long *zones_size, unsigned long *zholes_size)
{
	unsigned long realtotalpages, totalpages = 0;
	int i;

	for (i = 0; i < MAX_NR_ZONES; i++)
		totalpages += zones_size[i];
	pgdat->node_spanned_pages = totalpages;

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


/*
 * 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.
 */
1785
void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
L
Linus Torvalds 已提交
1786 1787 1788
		unsigned long start_pfn)
{
	struct page *page;
A
Andy Whitcroft 已提交
1789 1790
	unsigned long end_pfn = start_pfn + size;
	unsigned long pfn;
L
Linus Torvalds 已提交
1791

1792
	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
A
Andy Whitcroft 已提交
1793 1794 1795 1796
		if (!early_pfn_valid(pfn))
			continue;
		page = pfn_to_page(pfn);
		set_page_links(page, zone, nid, pfn);
1797
		init_page_count(page);
L
Linus Torvalds 已提交
1798 1799 1800 1801 1802 1803
		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))
1804
			set_page_address(page, __va(pfn << PAGE_SHIFT));
L
Linus Torvalds 已提交
1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818
#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;
	}
}

A
Andy Whitcroft 已提交
1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832
#define ZONETABLE_INDEX(x, zone_nr)	((x << ZONES_SHIFT) | zone_nr)
void zonetable_add(struct zone *zone, int nid, int zid, unsigned long pfn,
		unsigned long size)
{
	unsigned long snum = pfn_to_section_nr(pfn);
	unsigned long end = pfn_to_section_nr(pfn + size);

	if (FLAGS_HAS_NODE)
		zone_table[ZONETABLE_INDEX(nid, zid)] = zone;
	else
		for (; snum <= end; snum++)
			zone_table[ZONETABLE_INDEX(snum, zid)] = zone;
}

L
Linus Torvalds 已提交
1833 1834 1835 1836 1837
#ifndef __HAVE_ARCH_MEMMAP_INIT
#define memmap_init(size, nid, zone, start_pfn) \
	memmap_init_zone((size), (nid), (zone), (start_pfn))
#endif

1838
static int __cpuinit zone_batchsize(struct zone *zone)
1839 1840 1841 1842 1843
{
	int batch;

	/*
	 * The per-cpu-pages pools are set to around 1000th of the
1844
	 * size of the zone.  But no more than 1/2 of a meg.
1845 1846 1847 1848
	 *
	 * OK, so we don't know how big the cache is.  So guess.
	 */
	batch = zone->present_pages / 1024;
1849 1850
	if (batch * PAGE_SIZE > 512 * 1024)
		batch = (512 * 1024) / PAGE_SIZE;
1851 1852 1853 1854 1855
	batch /= 4;		/* We effectively *= 4 below */
	if (batch < 1)
		batch = 1;

	/*
1856 1857 1858
	 * 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.
1859
	 *
1860 1861 1862 1863
	 * 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.
1864
	 */
1865
	batch = (1 << (fls(batch + batch/2)-1)) - 1;
1866

1867 1868 1869
	return batch;
}

1870 1871 1872 1873
inline void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
{
	struct per_cpu_pages *pcp;

1874 1875
	memset(p, 0, sizeof(*p));

1876 1877 1878 1879 1880 1881 1882 1883 1884
	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;
1885
	pcp->batch = max(1UL, batch/2);
1886 1887 1888
	INIT_LIST_HEAD(&pcp->list);
}

1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906
/*
 * 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;
}


1907 1908
#ifdef CONFIG_NUMA
/*
1909 1910 1911 1912 1913 1914 1915
 * 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.
1916 1917 1918 1919 1920 1921 1922 1923
 *
 * 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.
1924
 */
1925
static struct per_cpu_pageset boot_pageset[NR_CPUS];
1926 1927 1928

/*
 * Dynamically allocate memory for the
1929 1930
 * per cpu pageset array in struct zone.
 */
1931
static int __cpuinit process_zones(int cpu)
1932 1933 1934 1935 1936
{
	struct zone *zone, *dzone;

	for_each_zone(zone) {

N
Nick Piggin 已提交
1937
		zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset),
1938
					 GFP_KERNEL, cpu_to_node(cpu));
N
Nick Piggin 已提交
1939
		if (!zone_pcp(zone, cpu))
1940 1941
			goto bad;

N
Nick Piggin 已提交
1942
		setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone));
1943 1944 1945 1946

		if (percpu_pagelist_fraction)
			setup_pagelist_highmark(zone_pcp(zone, cpu),
			 	(zone->present_pages / percpu_pagelist_fraction));
1947 1948 1949 1950 1951 1952 1953
	}

	return 0;
bad:
	for_each_zone(dzone) {
		if (dzone == zone)
			break;
N
Nick Piggin 已提交
1954 1955
		kfree(zone_pcp(dzone, cpu));
		zone_pcp(dzone, cpu) = NULL;
1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971
	}
	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);

		zone_pcp(zone, cpu) = NULL;
		kfree(pset);
	}
}

1972
static int pageset_cpuup_callback(struct notifier_block *nfb,
1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983
		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;
1984
		case CPU_UP_CANCELED:
1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996
		case CPU_DEAD:
			free_zone_pagesets(cpu);
			break;
		default:
			break;
	}
	return ret;
}

static struct notifier_block pageset_notifier =
	{ &pageset_cpuup_callback, NULL, 0 };

1997
void __init setup_per_cpu_pageset(void)
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
{
	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

2012
static __meminit
2013 2014 2015 2016 2017 2018 2019 2020 2021
void zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
{
	int i;
	struct pglist_data *pgdat = zone->zone_pgdat;

	/*
	 * The per-page waitqueue mechanism uses hashed waitqueues
	 * per zone.
	 */
2022 2023 2024 2025
	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);
2026
	zone->wait_table = (wait_queue_head_t *)
2027
		alloc_bootmem_node(pgdat, zone->wait_table_hash_nr_entries
2028 2029
					* sizeof(wait_queue_head_t));

2030
	for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
2031 2032 2033
		init_waitqueue_head(zone->wait_table + i);
}

2034
static __meminit void zone_pcp_init(struct zone *zone)
2035 2036 2037 2038 2039 2040 2041
{
	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
2042
		zone_pcp(zone, cpu) = &boot_pageset[cpu];
2043 2044 2045 2046 2047
		setup_pageset(&boot_pageset[cpu],0);
#else
		setup_pageset(zone_pcp(zone,cpu), batch);
#endif
	}
A
Anton Blanchard 已提交
2048 2049 2050
	if (zone->present_pages)
		printk(KERN_DEBUG "  %s zone: %lu pages, LIFO batch:%lu\n",
			zone->name, zone->present_pages, batch);
2051 2052
}

2053
static __meminit void init_currently_empty_zone(struct zone *zone,
2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067
		unsigned long zone_start_pfn, unsigned long size)
{
	struct pglist_data *pgdat = zone->zone_pgdat;

	zone_wait_table_init(zone, size);
	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);
}

L
Linus Torvalds 已提交
2068 2069 2070 2071 2072 2073 2074 2075 2076
/*
 * Set up the zone data structures:
 *   - mark all pages reserved
 *   - mark all memory queues empty
 *   - clear the memory bitmaps
 */
static void __init free_area_init_core(struct pglist_data *pgdat,
		unsigned long *zones_size, unsigned long *zholes_size)
{
2077 2078
	unsigned long j;
	int nid = pgdat->node_id;
L
Linus Torvalds 已提交
2079 2080
	unsigned long zone_start_pfn = pgdat->node_start_pfn;

2081
	pgdat_resize_init(pgdat);
L
Linus Torvalds 已提交
2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093
	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;
		unsigned long size, realsize;

		realsize = size = zones_size[j];
		if (zholes_size)
			realsize -= zholes_size[j];

A
Andi Kleen 已提交
2094
		if (j < ZONE_HIGHMEM)
L
Linus Torvalds 已提交
2095 2096 2097 2098 2099 2100 2101 2102
			nr_kernel_pages += realsize;
		nr_all_pages += realsize;

		zone->spanned_pages = size;
		zone->present_pages = realsize;
		zone->name = zone_names[j];
		spin_lock_init(&zone->lock);
		spin_lock_init(&zone->lru_lock);
2103
		zone_seqlock_init(zone);
L
Linus Torvalds 已提交
2104 2105 2106 2107 2108
		zone->zone_pgdat = pgdat;
		zone->free_pages = 0;

		zone->temp_priority = zone->prev_priority = DEF_PRIORITY;

2109
		zone_pcp_init(zone);
L
Linus Torvalds 已提交
2110 2111 2112 2113 2114 2115
		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;
2116
		atomic_set(&zone->reclaim_in_progress, 0);
L
Linus Torvalds 已提交
2117 2118 2119
		if (!size)
			continue;

A
Andy Whitcroft 已提交
2120
		zonetable_add(zone, nid, j, zone_start_pfn, size);
2121
		init_currently_empty_zone(zone, zone_start_pfn, size);
L
Linus Torvalds 已提交
2122 2123 2124 2125 2126 2127 2128 2129 2130 2131
		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
2132
#ifdef CONFIG_FLAT_NODE_MEM_MAP
L
Linus Torvalds 已提交
2133 2134
	/* ia64 gets its own node_mem_map, before this, without bootmem */
	if (!pgdat->node_mem_map) {
2135
		unsigned long size, start, end;
A
Andy Whitcroft 已提交
2136 2137
		struct page *map;

2138 2139 2140 2141 2142 2143 2144 2145 2146
		/*
		 * 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);
2147 2148 2149
		map = alloc_remap(pgdat->node_id, size);
		if (!map)
			map = alloc_bootmem_node(pgdat, size);
2150
		pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
L
Linus Torvalds 已提交
2151
	}
A
Andy Whitcroft 已提交
2152
#ifdef CONFIG_FLATMEM
L
Linus Torvalds 已提交
2153 2154 2155 2156 2157 2158
	/*
	 * With no DISCONTIG, the global mem_map is just set as node 0's
	 */
	if (pgdat == NODE_DATA(0))
		mem_map = NODE_DATA(0)->node_mem_map;
#endif
A
Andy Whitcroft 已提交
2159
#endif /* CONFIG_FLAT_NODE_MEM_MAP */
L
Linus Torvalds 已提交
2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174
}

void __init free_area_init_node(int nid, struct pglist_data *pgdat,
		unsigned long *zones_size, unsigned long node_start_pfn,
		unsigned long *zholes_size)
{
	pgdat->node_id = nid;
	pgdat->node_start_pfn = node_start_pfn;
	calculate_zone_totalpages(pgdat, zones_size, zholes_size);

	alloc_node_mem_map(pgdat);

	free_area_init_core(pgdat, zones_size, zholes_size);
}

2175
#ifndef CONFIG_NEED_MULTIPLE_NODES
L
Linus Torvalds 已提交
2176 2177 2178 2179
static bootmem_data_t contig_bootmem_data;
struct pglist_data contig_page_data = { .bdata = &contig_bootmem_data };

EXPORT_SYMBOL(contig_page_data);
2180
#endif
L
Linus Torvalds 已提交
2181 2182 2183

void __init free_area_init(unsigned long *zones_size)
{
2184
	free_area_init_node(0, NODE_DATA(0), zones_size,
L
Linus Torvalds 已提交
2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195
			__pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
}

#ifdef CONFIG_PROC_FS

#include <linux/seq_file.h>

static void *frag_start(struct seq_file *m, loff_t *pos)
{
	pg_data_t *pgdat;
	loff_t node = *pos;
2196 2197 2198
	for (pgdat = first_online_pgdat();
	     pgdat && node;
	     pgdat = next_online_pgdat(pgdat))
L
Linus Torvalds 已提交
2199 2200 2201 2202 2203 2204 2205 2206 2207 2208
		--node;

	return pgdat;
}

static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
{
	pg_data_t *pgdat = (pg_data_t *)arg;

	(*pos)++;
2209
	return next_online_pgdat(pgdat);
L
Linus Torvalds 已提交
2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227
}

static void frag_stop(struct seq_file *m, void *arg)
{
}

/* 
 * This walks the free areas for each zone.
 */
static int frag_show(struct seq_file *m, void *arg)
{
	pg_data_t *pgdat = (pg_data_t *)arg;
	struct zone *zone;
	struct zone *node_zones = pgdat->node_zones;
	unsigned long flags;
	int order;

	for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
2228
		if (!populated_zone(zone))
L
Linus Torvalds 已提交
2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247
			continue;

		spin_lock_irqsave(&zone->lock, flags);
		seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
		for (order = 0; order < MAX_ORDER; ++order)
			seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
		spin_unlock_irqrestore(&zone->lock, flags);
		seq_putc(m, '\n');
	}
	return 0;
}

struct seq_operations fragmentation_op = {
	.start	= frag_start,
	.next	= frag_next,
	.stop	= frag_stop,
	.show	= frag_show,
};

N
Nikita Danilov 已提交
2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260
/*
 * Output information about zones in @pgdat.
 */
static int zoneinfo_show(struct seq_file *m, void *arg)
{
	pg_data_t *pgdat = arg;
	struct zone *zone;
	struct zone *node_zones = pgdat->node_zones;
	unsigned long flags;

	for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; zone++) {
		int i;

2261
		if (!populated_zone(zone))
N
Nikita Danilov 已提交
2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293
			continue;

		spin_lock_irqsave(&zone->lock, flags);
		seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
		seq_printf(m,
			   "\n  pages free     %lu"
			   "\n        min      %lu"
			   "\n        low      %lu"
			   "\n        high     %lu"
			   "\n        active   %lu"
			   "\n        inactive %lu"
			   "\n        scanned  %lu (a: %lu i: %lu)"
			   "\n        spanned  %lu"
			   "\n        present  %lu",
			   zone->free_pages,
			   zone->pages_min,
			   zone->pages_low,
			   zone->pages_high,
			   zone->nr_active,
			   zone->nr_inactive,
			   zone->pages_scanned,
			   zone->nr_scan_active, zone->nr_scan_inactive,
			   zone->spanned_pages,
			   zone->present_pages);
		seq_printf(m,
			   "\n        protection: (%lu",
			   zone->lowmem_reserve[0]);
		for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
			seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
		seq_printf(m,
			   ")"
			   "\n  pagesets");
N
Nick Piggin 已提交
2294
		for_each_online_cpu(i) {
N
Nikita Danilov 已提交
2295 2296 2297
			struct per_cpu_pageset *pageset;
			int j;

2298
			pageset = zone_pcp(zone, i);
N
Nikita Danilov 已提交
2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354
			for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {
				if (pageset->pcp[j].count)
					break;
			}
			if (j == ARRAY_SIZE(pageset->pcp))
				continue;
			for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {
				seq_printf(m,
					   "\n    cpu: %i pcp: %i"
					   "\n              count: %i"
					   "\n              high:  %i"
					   "\n              batch: %i",
					   i, j,
					   pageset->pcp[j].count,
					   pageset->pcp[j].high,
					   pageset->pcp[j].batch);
			}
#ifdef CONFIG_NUMA
			seq_printf(m,
				   "\n            numa_hit:       %lu"
				   "\n            numa_miss:      %lu"
				   "\n            numa_foreign:   %lu"
				   "\n            interleave_hit: %lu"
				   "\n            local_node:     %lu"
				   "\n            other_node:     %lu",
				   pageset->numa_hit,
				   pageset->numa_miss,
				   pageset->numa_foreign,
				   pageset->interleave_hit,
				   pageset->local_node,
				   pageset->other_node);
#endif
		}
		seq_printf(m,
			   "\n  all_unreclaimable: %u"
			   "\n  prev_priority:     %i"
			   "\n  temp_priority:     %i"
			   "\n  start_pfn:         %lu",
			   zone->all_unreclaimable,
			   zone->prev_priority,
			   zone->temp_priority,
			   zone->zone_start_pfn);
		spin_unlock_irqrestore(&zone->lock, flags);
		seq_putc(m, '\n');
	}
	return 0;
}

struct seq_operations zoneinfo_op = {
	.start	= frag_start, /* iterate over all zones. The same as in
			       * fragmentation. */
	.next	= frag_next,
	.stop	= frag_stop,
	.show	= zoneinfo_show,
};

L
Linus Torvalds 已提交
2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367
static char *vmstat_text[] = {
	"nr_dirty",
	"nr_writeback",
	"nr_unstable",
	"nr_page_table_pages",
	"nr_mapped",
	"nr_slab",

	"pgpgin",
	"pgpgout",
	"pswpin",
	"pswpout",

N
Nick Piggin 已提交
2368
	"pgalloc_high",
L
Linus Torvalds 已提交
2369
	"pgalloc_normal",
N
Nick Piggin 已提交
2370
	"pgalloc_dma32",
L
Linus Torvalds 已提交
2371
	"pgalloc_dma",
N
Nick Piggin 已提交
2372

L
Linus Torvalds 已提交
2373 2374 2375 2376 2377 2378
	"pgfree",
	"pgactivate",
	"pgdeactivate",

	"pgfault",
	"pgmajfault",
N
Nick Piggin 已提交
2379

L
Linus Torvalds 已提交
2380 2381
	"pgrefill_high",
	"pgrefill_normal",
N
Nick Piggin 已提交
2382
	"pgrefill_dma32",
L
Linus Torvalds 已提交
2383 2384 2385 2386
	"pgrefill_dma",

	"pgsteal_high",
	"pgsteal_normal",
N
Nick Piggin 已提交
2387
	"pgsteal_dma32",
L
Linus Torvalds 已提交
2388
	"pgsteal_dma",
N
Nick Piggin 已提交
2389

L
Linus Torvalds 已提交
2390 2391
	"pgscan_kswapd_high",
	"pgscan_kswapd_normal",
N
Nick Piggin 已提交
2392
	"pgscan_kswapd_dma32",
L
Linus Torvalds 已提交
2393
	"pgscan_kswapd_dma",
N
Nick Piggin 已提交
2394

L
Linus Torvalds 已提交
2395 2396
	"pgscan_direct_high",
	"pgscan_direct_normal",
N
Nick Piggin 已提交
2397
	"pgscan_direct_dma32",
L
Linus Torvalds 已提交
2398 2399
	"pgscan_direct_dma",

N
Nick Piggin 已提交
2400
	"pginodesteal",
L
Linus Torvalds 已提交
2401 2402 2403 2404 2405 2406 2407
	"slabs_scanned",
	"kswapd_steal",
	"kswapd_inodesteal",
	"pageoutrun",
	"allocstall",

	"pgrotated",
2408
	"nr_bounce",
L
Linus Torvalds 已提交
2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498
};

static void *vmstat_start(struct seq_file *m, loff_t *pos)
{
	struct page_state *ps;

	if (*pos >= ARRAY_SIZE(vmstat_text))
		return NULL;

	ps = kmalloc(sizeof(*ps), GFP_KERNEL);
	m->private = ps;
	if (!ps)
		return ERR_PTR(-ENOMEM);
	get_full_page_state(ps);
	ps->pgpgin /= 2;		/* sectors -> kbytes */
	ps->pgpgout /= 2;
	return (unsigned long *)ps + *pos;
}

static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
{
	(*pos)++;
	if (*pos >= ARRAY_SIZE(vmstat_text))
		return NULL;
	return (unsigned long *)m->private + *pos;
}

static int vmstat_show(struct seq_file *m, void *arg)
{
	unsigned long *l = arg;
	unsigned long off = l - (unsigned long *)m->private;

	seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
	return 0;
}

static void vmstat_stop(struct seq_file *m, void *arg)
{
	kfree(m->private);
	m->private = NULL;
}

struct seq_operations vmstat_op = {
	.start	= vmstat_start,
	.next	= vmstat_next,
	.stop	= vmstat_stop,
	.show	= vmstat_show,
};

#endif /* CONFIG_PROC_FS */

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

	if (action == CPU_DEAD) {
		int i;

		/* Drain local pagecache count. */
		count = &per_cpu(nr_pagecache_local, cpu);
		atomic_add(*count, &nr_pagecache);
		*count = 0;
		local_irq_disable();
		__drain_pages(cpu);

		/* Add dead cpu's page_states to our own. */
		dest = (unsigned long *)&__get_cpu_var(page_states);
		src = (unsigned long *)&per_cpu(page_states, cpu);

		for (i = 0; i < sizeof(struct page_state)/sizeof(unsigned long);
				i++) {
			dest[i] += src[i];
			src[i] = 0;
		}

		local_irq_enable();
	}
	return NOTIFY_OK;
}
#endif /* CONFIG_HOTPLUG_CPU */

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

2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530
/*
 * 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;
	int i, j;

	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
2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541
/*
 * 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;
	int j, idx;

2542
	for_each_online_pgdat(pgdat) {
L
Linus Torvalds 已提交
2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561
		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;

			for (idx = j-1; idx >= 0; idx--) {
				struct zone *lower_zone;

				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;
			}
		}
	}
2562 2563 2564

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
2565 2566 2567 2568 2569 2570 2571
}

/*
 * 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.
 */
2572
void setup_per_zone_pages_min(void)
L
Linus Torvalds 已提交
2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585
{
	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) {
2586 2587
		u64 tmp;

L
Linus Torvalds 已提交
2588
		spin_lock_irqsave(&zone->lru_lock, flags);
2589 2590
		tmp = (u64)pages_min * zone->present_pages;
		do_div(tmp, lowmem_pages);
L
Linus Torvalds 已提交
2591 2592
		if (is_highmem(zone)) {
			/*
N
Nick Piggin 已提交
2593 2594 2595 2596 2597 2598 2599
			 * __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
2600 2601 2602 2603 2604 2605 2606 2607 2608 2609
			 */
			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
2610 2611
			/*
			 * If it's a lowmem zone, reserve a number of pages
L
Linus Torvalds 已提交
2612 2613
			 * proportionate to the zone's size.
			 */
N
Nick Piggin 已提交
2614
			zone->pages_min = tmp;
L
Linus Torvalds 已提交
2615 2616
		}

2617 2618
		zone->pages_low   = zone->pages_min + (tmp >> 2);
		zone->pages_high  = zone->pages_min + (tmp >> 1);
L
Linus Torvalds 已提交
2619 2620
		spin_unlock_irqrestore(&zone->lru_lock, flags);
	}
2621 2622 2623

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 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
}

/*
 * 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;
}

/*
 * 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;
}

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
/*
 * 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;
}

L
Linus Torvalds 已提交
2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768
__initdata int hashdist = HASHDIST_DEFAULT;

#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);
	}
2769
	numentries = roundup_pow_of_two(numentries);
L
Linus Torvalds 已提交
2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811

	/* 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;
}
2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834

#ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
/*
 * pfn <-> page translation. out-of-line version.
 * (see asm-generic/memory_model.h)
 */
#if defined(CONFIG_FLATMEM)
struct page *pfn_to_page(unsigned long pfn)
{
	return mem_map + (pfn - ARCH_PFN_OFFSET);
}
unsigned long page_to_pfn(struct page *page)
{
	return (page - mem_map) + ARCH_PFN_OFFSET;
}
#elif defined(CONFIG_DISCONTIGMEM)
struct page *pfn_to_page(unsigned long pfn)
{
	int nid = arch_pfn_to_nid(pfn);
	return NODE_DATA(nid)->node_mem_map + arch_local_page_offset(pfn,nid);
}
unsigned long page_to_pfn(struct page *page)
{
K
KAMEZAWA Hiroyuki 已提交
2835 2836
	struct pglist_data *pgdat = NODE_DATA(page_to_nid(page));
	return (page - pgdat->node_mem_map) + pgdat->node_start_pfn;
2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852
}
#elif defined(CONFIG_SPARSEMEM)
struct page *pfn_to_page(unsigned long pfn)
{
	return __section_mem_map_addr(__pfn_to_section(pfn)) + pfn;
}

unsigned long page_to_pfn(struct page *page)
{
	long section_id = page_to_section(page);
	return page - __section_mem_map_addr(__nr_to_section(section_id));
}
#endif /* CONFIG_FLATMEM/DISCONTIGMME/SPARSEMEM */
EXPORT_SYMBOL(pfn_to_page);
EXPORT_SYMBOL(page_to_pfn);
#endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */