blob: 791690d7d3fa02e4e5956af69fffedf654088adc [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/mm/page_alloc.c
3 *
4 * Manages the free list, the system allocates free pages here.
5 * Note that kmalloc() lives in slab.c
6 *
7 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
8 * Swap reorganised 29.12.95, Stephen Tweedie
9 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
10 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
11 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
12 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000
13 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
14 * (lots of bits borrowed from Ingo Molnar & Andrew Morton)
15 */
16
17#include <linux/config.h>
18#include <linux/stddef.h>
19#include <linux/mm.h>
20#include <linux/swap.h>
21#include <linux/interrupt.h>
22#include <linux/pagemap.h>
23#include <linux/bootmem.h>
24#include <linux/compiler.h>
Randy Dunlap9f158332005-09-13 01:25:16 -070025#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/module.h>
27#include <linux/suspend.h>
28#include <linux/pagevec.h>
29#include <linux/blkdev.h>
30#include <linux/slab.h>
31#include <linux/notifier.h>
32#include <linux/topology.h>
33#include <linux/sysctl.h>
34#include <linux/cpu.h>
35#include <linux/cpuset.h>
Dave Hansenbdc8cb92005-10-29 18:16:53 -070036#include <linux/memory_hotplug.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070037#include <linux/nodemask.h>
38#include <linux/vmalloc.h>
Christoph Lameter4be38e32006-01-06 00:11:17 -080039#include <linux/mempolicy.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070040
41#include <asm/tlbflush.h>
42#include "internal.h"
43
44/*
45 * MCD - HACK: Find somewhere to initialize this EARLY, or make this
46 * initializer cleaner
47 */
Christoph Lameterc3d8c142005-09-06 15:16:33 -070048nodemask_t node_online_map __read_mostly = { { [0] = 1UL } };
Dean Nelson7223a932005-03-23 19:00:00 -070049EXPORT_SYMBOL(node_online_map);
Christoph Lameterc3d8c142005-09-06 15:16:33 -070050nodemask_t node_possible_map __read_mostly = NODE_MASK_ALL;
Dean Nelson7223a932005-03-23 19:00:00 -070051EXPORT_SYMBOL(node_possible_map);
Christoph Lameterc3d8c142005-09-06 15:16:33 -070052struct pglist_data *pgdat_list __read_mostly;
Ravikiran G Thirumalai6c231b72005-09-06 15:17:45 -070053unsigned long totalram_pages __read_mostly;
54unsigned long totalhigh_pages __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070055long nr_swap_pages;
Rohit Seth8ad4b1f2006-01-08 01:00:40 -080056int percpu_pagelist_fraction;
Linus Torvalds1da177e2005-04-16 15:20:36 -070057
David Howellsa226f6c2006-01-06 00:11:08 -080058static void fastcall free_hot_cold_page(struct page *page, int cold);
Hugh Dickinsd98c7a02006-02-14 13:52:59 -080059static void __free_pages_ok(struct page *page, unsigned int order);
David Howellsa226f6c2006-01-06 00:11:08 -080060
Linus Torvalds1da177e2005-04-16 15:20:36 -070061/*
62 * results with 256, 32 in the lowmem_reserve sysctl:
63 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
64 * 1G machine -> (16M dma, 784M normal, 224M high)
65 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
66 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
67 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
Andi Kleena2f1b422005-11-05 17:25:53 +010068 *
69 * TBD: should special case ZONE_DMA32 machines here - in those we normally
70 * don't need any ZONE_NORMAL reservation
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 */
Andi Kleena2f1b422005-11-05 17:25:53 +010072int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { 256, 256, 32 };
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
74EXPORT_SYMBOL(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -070075
76/*
77 * Used by page_zone() to look up the address of the struct zone whose
78 * id is encoded in the upper bits of page->flags
79 */
Christoph Lameterc3d8c142005-09-06 15:16:33 -070080struct zone *zone_table[1 << ZONETABLE_SHIFT] __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070081EXPORT_SYMBOL(zone_table);
82
Andi Kleena2f1b422005-11-05 17:25:53 +010083static char *zone_names[MAX_NR_ZONES] = { "DMA", "DMA32", "Normal", "HighMem" };
Linus Torvalds1da177e2005-04-16 15:20:36 -070084int min_free_kbytes = 1024;
85
86unsigned long __initdata nr_kernel_pages;
87unsigned long __initdata nr_all_pages;
88
Nick Piggin13e74442006-01-06 00:10:58 -080089#ifdef CONFIG_DEBUG_VM
Dave Hansenc6a57e12005-10-29 18:16:52 -070090static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
Linus Torvalds1da177e2005-04-16 15:20:36 -070091{
Dave Hansenbdc8cb92005-10-29 18:16:53 -070092 int ret = 0;
93 unsigned seq;
94 unsigned long pfn = page_to_pfn(page);
Dave Hansenc6a57e12005-10-29 18:16:52 -070095
Dave Hansenbdc8cb92005-10-29 18:16:53 -070096 do {
97 seq = zone_span_seqbegin(zone);
98 if (pfn >= zone->zone_start_pfn + zone->spanned_pages)
99 ret = 1;
100 else if (pfn < zone->zone_start_pfn)
101 ret = 1;
102 } while (zone_span_seqretry(zone, seq));
103
104 return ret;
Dave Hansenc6a57e12005-10-29 18:16:52 -0700105}
106
107static int page_is_consistent(struct zone *zone, struct page *page)
108{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109#ifdef CONFIG_HOLES_IN_ZONE
110 if (!pfn_valid(page_to_pfn(page)))
Dave Hansenc6a57e12005-10-29 18:16:52 -0700111 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112#endif
113 if (zone != page_zone(page))
Dave Hansenc6a57e12005-10-29 18:16:52 -0700114 return 0;
115
116 return 1;
117}
118/*
119 * Temporary debugging check for pages not lying within a given zone.
120 */
121static int bad_range(struct zone *zone, struct page *page)
122{
123 if (page_outside_zone_boundaries(zone, page))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 return 1;
Dave Hansenc6a57e12005-10-29 18:16:52 -0700125 if (!page_is_consistent(zone, page))
126 return 1;
127
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 return 0;
129}
130
Nick Piggin13e74442006-01-06 00:10:58 -0800131#else
132static inline int bad_range(struct zone *zone, struct page *page)
133{
134 return 0;
135}
136#endif
137
Nick Piggin224abf92006-01-06 00:11:11 -0800138static void bad_page(struct page *page)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139{
Nick Piggin224abf92006-01-06 00:11:11 -0800140 printk(KERN_EMERG "Bad page state in process '%s'\n"
Hugh Dickins7365f3d2006-01-11 12:17:18 -0800141 KERN_EMERG "page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n"
142 KERN_EMERG "Trying to fix it up, but a reboot is needed\n"
143 KERN_EMERG "Backtrace:\n",
Nick Piggin224abf92006-01-06 00:11:11 -0800144 current->comm, page, (int)(2*sizeof(unsigned long)),
145 (unsigned long)page->flags, page->mapping,
146 page_mapcount(page), page_count(page));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 dump_stack();
Hugh Dickins334795e2005-06-21 17:15:08 -0700148 page->flags &= ~(1 << PG_lru |
149 1 << PG_private |
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 1 << PG_locked |
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 1 << PG_active |
152 1 << PG_dirty |
Hugh Dickins334795e2005-06-21 17:15:08 -0700153 1 << PG_reclaim |
154 1 << PG_slab |
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 1 << PG_swapcache |
Hugh Dickins689bceb2005-11-21 21:32:20 -0800156 1 << PG_writeback );
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 set_page_count(page, 0);
158 reset_page_mapcount(page);
159 page->mapping = NULL;
Randy Dunlap9f158332005-09-13 01:25:16 -0700160 add_taint(TAINT_BAD_PAGE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161}
162
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163/*
164 * Higher-order pages are called "compound pages". They are structured thusly:
165 *
166 * The first PAGE_SIZE page is called the "head page".
167 *
168 * The remaining PAGE_SIZE pages are called "tail pages".
169 *
170 * All pages have PG_compound set. All pages have their ->private pointing at
171 * the head page (even the head page has this).
172 *
Hugh Dickins41d78ba2006-02-14 13:52:58 -0800173 * The first tail page's ->lru.next holds the address of the compound page's
174 * put_page() function. Its ->lru.prev holds the order of allocation.
175 * This usage means that zero-order pages may not be compound.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 */
Hugh Dickinsd98c7a02006-02-14 13:52:59 -0800177
178static void free_compound_page(struct page *page)
179{
180 __free_pages_ok(page, (unsigned long)page[1].lru.prev);
181}
182
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183static void prep_compound_page(struct page *page, unsigned long order)
184{
185 int i;
186 int nr_pages = 1 << order;
187
Hugh Dickinsd98c7a02006-02-14 13:52:59 -0800188 page[1].lru.next = (void *)free_compound_page; /* set dtor */
Hugh Dickins41d78ba2006-02-14 13:52:58 -0800189 page[1].lru.prev = (void *)order;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 for (i = 0; i < nr_pages; i++) {
191 struct page *p = page + i;
192
193 SetPageCompound(p);
Hugh Dickins4c21e2f2005-10-29 18:16:40 -0700194 set_page_private(p, (unsigned long)page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 }
196}
197
198static void destroy_compound_page(struct page *page, unsigned long order)
199{
200 int i;
201 int nr_pages = 1 << order;
202
Hugh Dickins41d78ba2006-02-14 13:52:58 -0800203 if (unlikely((unsigned long)page[1].lru.prev != order))
Nick Piggin224abf92006-01-06 00:11:11 -0800204 bad_page(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205
206 for (i = 0; i < nr_pages; i++) {
207 struct page *p = page + i;
208
Nick Piggin224abf92006-01-06 00:11:11 -0800209 if (unlikely(!PageCompound(p) |
210 (page_private(p) != (unsigned long)page)))
211 bad_page(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 ClearPageCompound(p);
213 }
214}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
216/*
217 * function for dealing with page's order in buddy system.
218 * zone->lock is already acquired when we use these.
219 * So, we don't need atomic page->flags operations here.
220 */
221static inline unsigned long page_order(struct page *page) {
Hugh Dickins4c21e2f2005-10-29 18:16:40 -0700222 return page_private(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223}
224
225static inline void set_page_order(struct page *page, int order) {
Hugh Dickins4c21e2f2005-10-29 18:16:40 -0700226 set_page_private(page, order);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 __SetPagePrivate(page);
228}
229
230static inline void rmv_page_order(struct page *page)
231{
232 __ClearPagePrivate(page);
Hugh Dickins4c21e2f2005-10-29 18:16:40 -0700233 set_page_private(page, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234}
235
236/*
237 * Locate the struct page for both the matching buddy in our
238 * pair (buddy1) and the combined O(n+1) page they form (page).
239 *
240 * 1) Any buddy B1 will have an order O twin B2 which satisfies
241 * the following equation:
242 * B2 = B1 ^ (1 << O)
243 * For example, if the starting buddy (buddy2) is #8 its order
244 * 1 buddy is #10:
245 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
246 *
247 * 2) Any buddy B will have an order O+1 parent P which
248 * satisfies the following equation:
249 * P = B & ~(1 << O)
250 *
251 * Assumption: *_mem_map is contigious at least up to MAX_ORDER
252 */
253static inline struct page *
254__page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order)
255{
256 unsigned long buddy_idx = page_idx ^ (1 << order);
257
258 return page + (buddy_idx - page_idx);
259}
260
261static inline unsigned long
262__find_combined_index(unsigned long page_idx, unsigned int order)
263{
264 return (page_idx & ~(1 << order));
265}
266
267/*
268 * This function checks whether a page is free && is the buddy
269 * we can do coalesce a page and its buddy if
Nick Piggin13e74442006-01-06 00:10:58 -0800270 * (a) the buddy is not in a hole &&
271 * (b) the buddy is free &&
272 * (c) the buddy is on the buddy system &&
273 * (d) a page and its buddy have the same order.
Hugh Dickins4c21e2f2005-10-29 18:16:40 -0700274 * for recording page's order, we use page_private(page) and PG_private.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 *
276 */
277static inline int page_is_buddy(struct page *page, int order)
278{
Nick Piggin13e74442006-01-06 00:10:58 -0800279#ifdef CONFIG_HOLES_IN_ZONE
280 if (!pfn_valid(page_to_pfn(page)))
281 return 0;
282#endif
283
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284 if (PagePrivate(page) &&
285 (page_order(page) == order) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 page_count(page) == 0)
287 return 1;
288 return 0;
289}
290
291/*
292 * Freeing function for a buddy system allocator.
293 *
294 * The concept of a buddy system is to maintain direct-mapped table
295 * (containing bit values) for memory blocks of various "orders".
296 * The bottom level table contains the map for the smallest allocatable
297 * units of memory (here, pages), and each level above it describes
298 * pairs of units from the levels below, hence, "buddies".
299 * At a high level, all that happens here is marking the table entry
300 * at the bottom level available, and propagating the changes upward
301 * as necessary, plus some accounting needed to play nicely with other
302 * parts of the VM system.
303 * At each level, we keep a list of pages, which are heads of continuous
304 * free pages of length of (1 << order) and marked with PG_Private.Page's
Hugh Dickins4c21e2f2005-10-29 18:16:40 -0700305 * order is recorded in page_private(page) field.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 * So when we are allocating or freeing one, we can derive the state of the
307 * other. That is, if we allocate a small block, and both were
308 * free, the remainder of the region must be split into blocks.
309 * If a block is freed, and its buddy is also free, then this
310 * triggers coalescing into a block of larger size.
311 *
312 * -- wli
313 */
314
Nick Piggin48db57f2006-01-08 01:00:42 -0800315static inline void __free_one_page(struct page *page,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316 struct zone *zone, unsigned int order)
317{
318 unsigned long page_idx;
319 int order_size = 1 << order;
320
Nick Piggin224abf92006-01-06 00:11:11 -0800321 if (unlikely(PageCompound(page)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 destroy_compound_page(page, order);
323
324 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
325
326 BUG_ON(page_idx & (order_size - 1));
327 BUG_ON(bad_range(zone, page));
328
329 zone->free_pages += order_size;
330 while (order < MAX_ORDER-1) {
331 unsigned long combined_idx;
332 struct free_area *area;
333 struct page *buddy;
334
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 buddy = __page_find_buddy(page, page_idx, order);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 if (!page_is_buddy(buddy, order))
337 break; /* Move the buddy up one level. */
Nick Piggin13e74442006-01-06 00:10:58 -0800338
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 list_del(&buddy->lru);
340 area = zone->free_area + order;
341 area->nr_free--;
342 rmv_page_order(buddy);
Nick Piggin13e74442006-01-06 00:10:58 -0800343 combined_idx = __find_combined_index(page_idx, order);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 page = page + (combined_idx - page_idx);
345 page_idx = combined_idx;
346 order++;
347 }
348 set_page_order(page, order);
349 list_add(&page->lru, &zone->free_area[order].free_list);
350 zone->free_area[order].nr_free++;
351}
352
Nick Piggin224abf92006-01-06 00:11:11 -0800353static inline int free_pages_check(struct page *page)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354{
Nick Piggin92be2e32006-01-06 00:10:57 -0800355 if (unlikely(page_mapcount(page) |
356 (page->mapping != NULL) |
357 (page_count(page) != 0) |
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358 (page->flags & (
359 1 << PG_lru |
360 1 << PG_private |
361 1 << PG_locked |
362 1 << PG_active |
363 1 << PG_reclaim |
364 1 << PG_slab |
365 1 << PG_swapcache |
Nick Pigginb5810032005-10-29 18:16:12 -0700366 1 << PG_writeback |
Nick Piggin92be2e32006-01-06 00:10:57 -0800367 1 << PG_reserved ))))
Nick Piggin224abf92006-01-06 00:11:11 -0800368 bad_page(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369 if (PageDirty(page))
Nick Piggin242e5462005-09-03 15:54:50 -0700370 __ClearPageDirty(page);
Hugh Dickins689bceb2005-11-21 21:32:20 -0800371 /*
372 * For now, we report if PG_reserved was found set, but do not
373 * clear it, and do not free the page. But we shall soon need
374 * to do more, for when the ZERO_PAGE count wraps negative.
375 */
376 return PageReserved(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377}
378
379/*
380 * Frees a list of pages.
381 * Assumes all pages on list are in same zone, and of same order.
Renaud Lienhart207f36e2005-09-10 00:26:59 -0700382 * count is the number of pages to free.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 *
384 * If the zone was previously in an "all pages pinned" state then look to
385 * see if this freeing clears that state.
386 *
387 * And clear the zone's pages_scanned counter, to hold off the "all pages are
388 * pinned" detection logic.
389 */
Nick Piggin48db57f2006-01-08 01:00:42 -0800390static void free_pages_bulk(struct zone *zone, int count,
391 struct list_head *list, int order)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392{
Nick Pigginc54ad302006-01-06 00:10:56 -0800393 spin_lock(&zone->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 zone->all_unreclaimable = 0;
395 zone->pages_scanned = 0;
Nick Piggin48db57f2006-01-08 01:00:42 -0800396 while (count--) {
397 struct page *page;
398
399 BUG_ON(list_empty(list));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400 page = list_entry(list->prev, struct page, lru);
Nick Piggin48db57f2006-01-08 01:00:42 -0800401 /* have to delete it as __free_one_page list manipulates */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 list_del(&page->lru);
Nick Piggin48db57f2006-01-08 01:00:42 -0800403 __free_one_page(page, zone, order);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 }
Nick Pigginc54ad302006-01-06 00:10:56 -0800405 spin_unlock(&zone->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406}
407
Nick Piggin48db57f2006-01-08 01:00:42 -0800408static void free_one_page(struct zone *zone, struct page *page, int order)
409{
410 LIST_HEAD(list);
411 list_add(&page->lru, &list);
412 free_pages_bulk(zone, 1, &list, order);
413}
414
415static void __free_pages_ok(struct page *page, unsigned int order)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416{
Nick Pigginc54ad302006-01-06 00:10:56 -0800417 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 int i;
Hugh Dickins689bceb2005-11-21 21:32:20 -0800419 int reserved = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420
421 arch_free_page(page, order);
Ingo Molnarde5097c2006-01-09 15:59:21 -0800422 if (!PageHighMem(page))
423 mutex_debug_check_no_locks_freed(page_address(page),
David Woodhousea4fc7ab2006-01-11 14:41:26 +0000424 PAGE_SIZE<<order);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426#ifndef CONFIG_MMU
Nick Piggin48db57f2006-01-08 01:00:42 -0800427 for (i = 1 ; i < (1 << order) ; ++i)
428 __put_page(page + i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429#endif
430
431 for (i = 0 ; i < (1 << order) ; ++i)
Nick Piggin224abf92006-01-06 00:11:11 -0800432 reserved += free_pages_check(page + i);
Hugh Dickins689bceb2005-11-21 21:32:20 -0800433 if (reserved)
434 return;
435
Nick Piggin48db57f2006-01-08 01:00:42 -0800436 kernel_map_pages(page, 1 << order, 0);
Nick Pigginc54ad302006-01-06 00:10:56 -0800437 local_irq_save(flags);
Nick Piggina74609f2006-01-06 00:11:20 -0800438 __mod_page_state(pgfree, 1 << order);
Nick Piggin48db57f2006-01-08 01:00:42 -0800439 free_one_page(page_zone(page), page, order);
Nick Pigginc54ad302006-01-06 00:10:56 -0800440 local_irq_restore(flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441}
442
David Howellsa226f6c2006-01-06 00:11:08 -0800443/*
444 * permit the bootmem allocator to evade page validation on high-order frees
445 */
446void fastcall __init __free_pages_bootmem(struct page *page, unsigned int order)
447{
448 if (order == 0) {
449 __ClearPageReserved(page);
450 set_page_count(page, 0);
451
452 free_hot_cold_page(page, 0);
453 } else {
454 LIST_HEAD(list);
455 int loop;
456
457 for (loop = 0; loop < BITS_PER_LONG; loop++) {
458 struct page *p = &page[loop];
459
460 if (loop + 16 < BITS_PER_LONG)
461 prefetchw(p + 16);
462 __ClearPageReserved(p);
463 set_page_count(p, 0);
464 }
465
466 arch_free_page(page, order);
467
468 mod_page_state(pgfree, 1 << order);
469
470 list_add(&page->lru, &list);
471 kernel_map_pages(page, 1 << order, 0);
472 free_pages_bulk(page_zone(page), 1, &list, order);
473 }
474}
475
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476
477/*
478 * The order of subdivision here is critical for the IO subsystem.
479 * Please do not alter this order without good reasons and regression
480 * testing. Specifically, as large blocks of memory are subdivided,
481 * the order in which smaller blocks are delivered depends on the order
482 * they're subdivided in this function. This is the primary factor
483 * influencing the order in which pages are delivered to the IO
484 * subsystem according to empirical testing, and this is also justified
485 * by considering the behavior of a buddy system containing a single
486 * large block of memory acted on by a series of small allocations.
487 * This behavior is a critical factor in sglist merging's success.
488 *
489 * -- wli
490 */
Nick Piggin085cc7d2006-01-06 00:11:01 -0800491static inline void expand(struct zone *zone, struct page *page,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492 int low, int high, struct free_area *area)
493{
494 unsigned long size = 1 << high;
495
496 while (high > low) {
497 area--;
498 high--;
499 size >>= 1;
500 BUG_ON(bad_range(zone, &page[size]));
501 list_add(&page[size].lru, &area->free_list);
502 area->nr_free++;
503 set_page_order(&page[size], high);
504 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505}
506
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507/*
508 * This page is about to be returned from the page allocator
509 */
Hugh Dickins689bceb2005-11-21 21:32:20 -0800510static int prep_new_page(struct page *page, int order)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511{
Nick Piggin92be2e32006-01-06 00:10:57 -0800512 if (unlikely(page_mapcount(page) |
513 (page->mapping != NULL) |
514 (page_count(page) != 0) |
Hugh Dickins334795e2005-06-21 17:15:08 -0700515 (page->flags & (
516 1 << PG_lru |
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 1 << PG_private |
518 1 << PG_locked |
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519 1 << PG_active |
520 1 << PG_dirty |
521 1 << PG_reclaim |
Hugh Dickins334795e2005-06-21 17:15:08 -0700522 1 << PG_slab |
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 1 << PG_swapcache |
Nick Pigginb5810032005-10-29 18:16:12 -0700524 1 << PG_writeback |
Nick Piggin92be2e32006-01-06 00:10:57 -0800525 1 << PG_reserved ))))
Nick Piggin224abf92006-01-06 00:11:11 -0800526 bad_page(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527
Hugh Dickins689bceb2005-11-21 21:32:20 -0800528 /*
529 * For now, we report if PG_reserved was found set, but do not
530 * clear it, and do not allocate the page: as a safety net.
531 */
532 if (PageReserved(page))
533 return 1;
534
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535 page->flags &= ~(1 << PG_uptodate | 1 << PG_error |
536 1 << PG_referenced | 1 << PG_arch_1 |
537 1 << PG_checked | 1 << PG_mappedtodisk);
Hugh Dickins4c21e2f2005-10-29 18:16:40 -0700538 set_page_private(page, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539 set_page_refs(page, order);
540 kernel_map_pages(page, 1 << order, 1);
Hugh Dickins689bceb2005-11-21 21:32:20 -0800541 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542}
543
544/*
545 * Do the hard work of removing an element from the buddy allocator.
546 * Call me with the zone->lock already held.
547 */
548static struct page *__rmqueue(struct zone *zone, unsigned int order)
549{
550 struct free_area * area;
551 unsigned int current_order;
552 struct page *page;
553
554 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
555 area = zone->free_area + current_order;
556 if (list_empty(&area->free_list))
557 continue;
558
559 page = list_entry(area->free_list.next, struct page, lru);
560 list_del(&page->lru);
561 rmv_page_order(page);
562 area->nr_free--;
563 zone->free_pages -= 1UL << order;
Nick Piggin085cc7d2006-01-06 00:11:01 -0800564 expand(zone, page, order, current_order, area);
565 return page;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566 }
567
568 return NULL;
569}
570
571/*
572 * Obtain a specified number of elements from the buddy allocator, all under
573 * a single hold of the lock, for efficiency. Add them to the supplied list.
574 * Returns the number of new pages which were placed at *list.
575 */
576static int rmqueue_bulk(struct zone *zone, unsigned int order,
577 unsigned long count, struct list_head *list)
578{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580
Nick Pigginc54ad302006-01-06 00:10:56 -0800581 spin_lock(&zone->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582 for (i = 0; i < count; ++i) {
Nick Piggin085cc7d2006-01-06 00:11:01 -0800583 struct page *page = __rmqueue(zone, order);
584 if (unlikely(page == NULL))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586 list_add_tail(&page->lru, list);
587 }
Nick Pigginc54ad302006-01-06 00:10:56 -0800588 spin_unlock(&zone->lock);
Nick Piggin085cc7d2006-01-06 00:11:01 -0800589 return i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590}
591
Christoph Lameter4ae7c032005-06-21 17:14:57 -0700592#ifdef CONFIG_NUMA
593/* Called from the slab reaper to drain remote pagesets */
594void drain_remote_pages(void)
595{
596 struct zone *zone;
597 int i;
598 unsigned long flags;
599
600 local_irq_save(flags);
601 for_each_zone(zone) {
602 struct per_cpu_pageset *pset;
603
604 /* Do not drain local pagesets */
605 if (zone->zone_pgdat->node_id == numa_node_id())
606 continue;
607
Nick Piggin23316bc2006-01-08 01:00:41 -0800608 pset = zone_pcp(zone, smp_processor_id());
Christoph Lameter4ae7c032005-06-21 17:14:57 -0700609 for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) {
610 struct per_cpu_pages *pcp;
611
612 pcp = &pset->pcp[i];
Nick Piggin48db57f2006-01-08 01:00:42 -0800613 free_pages_bulk(zone, pcp->count, &pcp->list, 0);
614 pcp->count = 0;
Christoph Lameter4ae7c032005-06-21 17:14:57 -0700615 }
616 }
617 local_irq_restore(flags);
618}
619#endif
620
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621#if defined(CONFIG_PM) || defined(CONFIG_HOTPLUG_CPU)
622static void __drain_pages(unsigned int cpu)
623{
Nick Pigginc54ad302006-01-06 00:10:56 -0800624 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625 struct zone *zone;
626 int i;
627
628 for_each_zone(zone) {
629 struct per_cpu_pageset *pset;
630
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700631 pset = zone_pcp(zone, cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632 for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) {
633 struct per_cpu_pages *pcp;
634
635 pcp = &pset->pcp[i];
Nick Pigginc54ad302006-01-06 00:10:56 -0800636 local_irq_save(flags);
Nick Piggin48db57f2006-01-08 01:00:42 -0800637 free_pages_bulk(zone, pcp->count, &pcp->list, 0);
638 pcp->count = 0;
Nick Pigginc54ad302006-01-06 00:10:56 -0800639 local_irq_restore(flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640 }
641 }
642}
643#endif /* CONFIG_PM || CONFIG_HOTPLUG_CPU */
644
645#ifdef CONFIG_PM
646
647void mark_free_pages(struct zone *zone)
648{
649 unsigned long zone_pfn, flags;
650 int order;
651 struct list_head *curr;
652
653 if (!zone->spanned_pages)
654 return;
655
656 spin_lock_irqsave(&zone->lock, flags);
657 for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
658 ClearPageNosaveFree(pfn_to_page(zone_pfn + zone->zone_start_pfn));
659
660 for (order = MAX_ORDER - 1; order >= 0; --order)
661 list_for_each(curr, &zone->free_area[order].free_list) {
662 unsigned long start_pfn, i;
663
664 start_pfn = page_to_pfn(list_entry(curr, struct page, lru));
665
666 for (i=0; i < (1<<order); i++)
667 SetPageNosaveFree(pfn_to_page(start_pfn+i));
668 }
669 spin_unlock_irqrestore(&zone->lock, flags);
670}
671
672/*
673 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
674 */
675void drain_local_pages(void)
676{
677 unsigned long flags;
678
679 local_irq_save(flags);
680 __drain_pages(smp_processor_id());
681 local_irq_restore(flags);
682}
683#endif /* CONFIG_PM */
684
Nick Piggina74609f2006-01-06 00:11:20 -0800685static void zone_statistics(struct zonelist *zonelist, struct zone *z, int cpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686{
687#ifdef CONFIG_NUMA
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688 pg_data_t *pg = z->zone_pgdat;
689 pg_data_t *orig = zonelist->zones[0]->zone_pgdat;
690 struct per_cpu_pageset *p;
691
Nick Piggina74609f2006-01-06 00:11:20 -0800692 p = zone_pcp(z, cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693 if (pg == orig) {
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700694 p->numa_hit++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 } else {
696 p->numa_miss++;
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700697 zone_pcp(zonelist->zones[0], cpu)->numa_foreign++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 }
699 if (pg == NODE_DATA(numa_node_id()))
700 p->local_node++;
701 else
702 p->other_node++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703#endif
704}
705
706/*
707 * Free a 0-order page
708 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709static void fastcall free_hot_cold_page(struct page *page, int cold)
710{
711 struct zone *zone = page_zone(page);
712 struct per_cpu_pages *pcp;
713 unsigned long flags;
714
715 arch_free_page(page, 0);
716
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717 if (PageAnon(page))
718 page->mapping = NULL;
Nick Piggin224abf92006-01-06 00:11:11 -0800719 if (free_pages_check(page))
Hugh Dickins689bceb2005-11-21 21:32:20 -0800720 return;
721
Hugh Dickins689bceb2005-11-21 21:32:20 -0800722 kernel_map_pages(page, 1, 0);
723
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700724 pcp = &zone_pcp(zone, get_cpu())->pcp[cold];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725 local_irq_save(flags);
Nick Piggina74609f2006-01-06 00:11:20 -0800726 __inc_page_state(pgfree);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727 list_add(&page->lru, &pcp->list);
728 pcp->count++;
Nick Piggin48db57f2006-01-08 01:00:42 -0800729 if (pcp->count >= pcp->high) {
730 free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
731 pcp->count -= pcp->batch;
732 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733 local_irq_restore(flags);
734 put_cpu();
735}
736
737void fastcall free_hot_page(struct page *page)
738{
739 free_hot_cold_page(page, 0);
740}
741
742void fastcall free_cold_page(struct page *page)
743{
744 free_hot_cold_page(page, 1);
745}
746
Al Virodd0fc662005-10-07 07:46:04 +0100747static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748{
749 int i;
750
751 BUG_ON((gfp_flags & (__GFP_WAIT | __GFP_HIGHMEM)) == __GFP_HIGHMEM);
752 for(i = 0; i < (1 << order); i++)
753 clear_highpage(page + i);
754}
755
756/*
757 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
758 * we cheat by calling it from here, in the order > 0 path. Saves a branch
759 * or two.
760 */
Nick Piggina74609f2006-01-06 00:11:20 -0800761static struct page *buffered_rmqueue(struct zonelist *zonelist,
762 struct zone *zone, int order, gfp_t gfp_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763{
764 unsigned long flags;
Hugh Dickins689bceb2005-11-21 21:32:20 -0800765 struct page *page;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766 int cold = !!(gfp_flags & __GFP_COLD);
Nick Piggina74609f2006-01-06 00:11:20 -0800767 int cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768
Hugh Dickins689bceb2005-11-21 21:32:20 -0800769again:
Nick Piggina74609f2006-01-06 00:11:20 -0800770 cpu = get_cpu();
Nick Piggin48db57f2006-01-08 01:00:42 -0800771 if (likely(order == 0)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772 struct per_cpu_pages *pcp;
773
Nick Piggina74609f2006-01-06 00:11:20 -0800774 pcp = &zone_pcp(zone, cpu)->pcp[cold];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775 local_irq_save(flags);
Nick Piggina74609f2006-01-06 00:11:20 -0800776 if (!pcp->count) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 pcp->count += rmqueue_bulk(zone, 0,
778 pcp->batch, &pcp->list);
Nick Piggina74609f2006-01-06 00:11:20 -0800779 if (unlikely(!pcp->count))
780 goto failed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781 }
Nick Piggina74609f2006-01-06 00:11:20 -0800782 page = list_entry(pcp->list.next, struct page, lru);
783 list_del(&page->lru);
784 pcp->count--;
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800785 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786 spin_lock_irqsave(&zone->lock, flags);
787 page = __rmqueue(zone, order);
Nick Piggina74609f2006-01-06 00:11:20 -0800788 spin_unlock(&zone->lock);
789 if (!page)
790 goto failed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791 }
792
Nick Piggina74609f2006-01-06 00:11:20 -0800793 __mod_page_state_zone(zone, pgalloc, 1 << order);
794 zone_statistics(zonelist, zone, cpu);
795 local_irq_restore(flags);
796 put_cpu();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797
Nick Piggina74609f2006-01-06 00:11:20 -0800798 BUG_ON(bad_range(zone, page));
799 if (prep_new_page(page, order))
800 goto again;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801
Nick Piggina74609f2006-01-06 00:11:20 -0800802 if (gfp_flags & __GFP_ZERO)
803 prep_zero_page(page, order, gfp_flags);
804
805 if (order && (gfp_flags & __GFP_COMP))
806 prep_compound_page(page, order);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807 return page;
Nick Piggina74609f2006-01-06 00:11:20 -0800808
809failed:
810 local_irq_restore(flags);
811 put_cpu();
812 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700813}
814
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800815#define ALLOC_NO_WATERMARKS 0x01 /* don't check watermarks at all */
Nick Piggin31488902005-11-28 13:44:03 -0800816#define ALLOC_WMARK_MIN 0x02 /* use pages_min watermark */
817#define ALLOC_WMARK_LOW 0x04 /* use pages_low watermark */
818#define ALLOC_WMARK_HIGH 0x08 /* use pages_high watermark */
819#define ALLOC_HARDER 0x10 /* try to alloc harder */
820#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
821#define ALLOC_CPUSET 0x40 /* check for correct cpuset */
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800822
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823/*
824 * Return 1 if free pages are above 'mark'. This takes into account the order
825 * of the allocation.
826 */
827int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800828 int classzone_idx, int alloc_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829{
830 /* free_pages my go negative - that's OK */
831 long min = mark, free_pages = z->free_pages - (1 << order) + 1;
832 int o;
833
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800834 if (alloc_flags & ALLOC_HIGH)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835 min -= min / 2;
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800836 if (alloc_flags & ALLOC_HARDER)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837 min -= min / 4;
838
839 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
840 return 0;
841 for (o = 0; o < order; o++) {
842 /* At the next order, this order's pages become unavailable */
843 free_pages -= z->free_area[o].nr_free << o;
844
845 /* Require fewer higher order pages to be free */
846 min >>= 1;
847
848 if (free_pages <= min)
849 return 0;
850 }
851 return 1;
852}
853
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800854/*
855 * get_page_from_freeliest goes through the zonelist trying to allocate
856 * a page.
857 */
858static struct page *
859get_page_from_freelist(gfp_t gfp_mask, unsigned int order,
860 struct zonelist *zonelist, int alloc_flags)
Martin Hicks753ee722005-06-21 17:14:41 -0700861{
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800862 struct zone **z = zonelist->zones;
863 struct page *page = NULL;
864 int classzone_idx = zone_idx(*z);
865
866 /*
867 * Go through the zonelist once, looking for a zone with enough free.
868 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
869 */
870 do {
871 if ((alloc_flags & ALLOC_CPUSET) &&
872 !cpuset_zone_allowed(*z, gfp_mask))
873 continue;
874
875 if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
Nick Piggin31488902005-11-28 13:44:03 -0800876 unsigned long mark;
877 if (alloc_flags & ALLOC_WMARK_MIN)
878 mark = (*z)->pages_min;
879 else if (alloc_flags & ALLOC_WMARK_LOW)
880 mark = (*z)->pages_low;
881 else
882 mark = (*z)->pages_high;
883 if (!zone_watermark_ok(*z, order, mark,
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800884 classzone_idx, alloc_flags))
Christoph Lameter9eeff232006-01-18 17:42:31 -0800885 if (!zone_reclaim_mode ||
886 !zone_reclaim(*z, gfp_mask, order))
887 continue;
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800888 }
889
Nick Piggina74609f2006-01-06 00:11:20 -0800890 page = buffered_rmqueue(zonelist, *z, order, gfp_mask);
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800891 if (page) {
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800892 break;
893 }
894 } while (*(++z) != NULL);
895 return page;
Martin Hicks753ee722005-06-21 17:14:41 -0700896}
897
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898/*
899 * This is the 'heart' of the zoned buddy allocator.
900 */
901struct page * fastcall
Al Virodd0fc662005-10-07 07:46:04 +0100902__alloc_pages(gfp_t gfp_mask, unsigned int order,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903 struct zonelist *zonelist)
904{
Al Viro260b2362005-10-21 03:22:44 -0400905 const gfp_t wait = gfp_mask & __GFP_WAIT;
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800906 struct zone **z;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907 struct page *page;
908 struct reclaim_state reclaim_state;
909 struct task_struct *p = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910 int do_retry;
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800911 int alloc_flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700912 int did_some_progress;
913
914 might_sleep_if(wait);
915
Jens Axboe6b1de912005-11-17 21:35:02 +0100916restart:
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800917 z = zonelist->zones; /* the list of zones suitable for gfp_mask */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800919 if (unlikely(*z == NULL)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920 /* Should this ever happen?? */
921 return NULL;
922 }
Jens Axboe6b1de912005-11-17 21:35:02 +0100923
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800924 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order,
Nick Piggin31488902005-11-28 13:44:03 -0800925 zonelist, ALLOC_WMARK_LOW|ALLOC_CPUSET);
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800926 if (page)
927 goto got_pg;
928
Jens Axboe6b1de912005-11-17 21:35:02 +0100929 do {
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800930 wakeup_kswapd(*z, order);
Jens Axboe6b1de912005-11-17 21:35:02 +0100931 } while (*(++z));
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800932
Paul Jackson9bf22292005-09-06 15:18:12 -0700933 /*
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800934 * OK, we're below the kswapd watermark and have kicked background
935 * reclaim. Now things get more complex, so set up alloc_flags according
936 * to how we want to proceed.
937 *
938 * The caller may dip into page reserves a bit more if the caller
939 * cannot run direct reclaim, or if the caller has realtime scheduling
Paul Jackson4eac9152006-01-11 12:17:19 -0800940 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
941 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
Paul Jackson9bf22292005-09-06 15:18:12 -0700942 */
Nick Piggin31488902005-11-28 13:44:03 -0800943 alloc_flags = ALLOC_WMARK_MIN;
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800944 if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait)
945 alloc_flags |= ALLOC_HARDER;
946 if (gfp_mask & __GFP_HIGH)
947 alloc_flags |= ALLOC_HIGH;
Paul Jackson47f3a862006-01-06 00:10:32 -0800948 alloc_flags |= ALLOC_CPUSET;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949
950 /*
951 * Go through the zonelist again. Let __GFP_HIGH and allocations
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800952 * coming from realtime tasks go deeper into reserves.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953 *
954 * This is the last chance, in general, before the goto nopage.
955 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
Paul Jackson9bf22292005-09-06 15:18:12 -0700956 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700957 */
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800958 page = get_page_from_freelist(gfp_mask, order, zonelist, alloc_flags);
959 if (page)
960 goto got_pg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961
962 /* This allocation should allow future memory freeing. */
Nick Pigginb84a35b2005-05-01 08:58:36 -0700963
964 if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE)))
965 && !in_interrupt()) {
966 if (!(gfp_mask & __GFP_NOMEMALLOC)) {
Kirill Korotaev885036d2005-11-13 16:06:41 -0800967nofail_alloc:
Nick Pigginb84a35b2005-05-01 08:58:36 -0700968 /* go through the zonelist yet again, ignoring mins */
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800969 page = get_page_from_freelist(gfp_mask, order,
Paul Jackson47f3a862006-01-06 00:10:32 -0800970 zonelist, ALLOC_NO_WATERMARKS);
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800971 if (page)
972 goto got_pg;
Kirill Korotaev885036d2005-11-13 16:06:41 -0800973 if (gfp_mask & __GFP_NOFAIL) {
974 blk_congestion_wait(WRITE, HZ/50);
975 goto nofail_alloc;
976 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977 }
978 goto nopage;
979 }
980
981 /* Atomic allocations - we can't balance anything */
982 if (!wait)
983 goto nopage;
984
985rebalance:
986 cond_resched();
987
988 /* We now go into synchronous reclaim */
Paul Jackson3e0d98b2006-01-08 01:01:49 -0800989 cpuset_memory_pressure_bump();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700990 p->flags |= PF_MEMALLOC;
991 reclaim_state.reclaimed_slab = 0;
992 p->reclaim_state = &reclaim_state;
993
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800994 did_some_progress = try_to_free_pages(zonelist->zones, gfp_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700995
996 p->reclaim_state = NULL;
997 p->flags &= ~PF_MEMALLOC;
998
999 cond_resched();
1000
1001 if (likely(did_some_progress)) {
Rohit Seth7fb1d9f2005-11-13 16:06:43 -08001002 page = get_page_from_freelist(gfp_mask, order,
1003 zonelist, alloc_flags);
1004 if (page)
1005 goto got_pg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001006 } else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
1007 /*
1008 * Go through the zonelist yet one more time, keep
1009 * very high watermark here, this is only to catch
1010 * a parallel oom killing, we must fail if we're still
1011 * under heavy pressure.
1012 */
Rohit Seth7fb1d9f2005-11-13 16:06:43 -08001013 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order,
Nick Piggin31488902005-11-28 13:44:03 -08001014 zonelist, ALLOC_WMARK_HIGH|ALLOC_CPUSET);
Rohit Seth7fb1d9f2005-11-13 16:06:43 -08001015 if (page)
1016 goto got_pg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017
Christoph Lameter9b0f8b02006-02-20 18:27:52 -08001018 out_of_memory(zonelist, gfp_mask, order);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001019 goto restart;
1020 }
1021
1022 /*
1023 * Don't let big-order allocations loop unless the caller explicitly
1024 * requests that. Wait for some write requests to complete then retry.
1025 *
1026 * In this implementation, __GFP_REPEAT means __GFP_NOFAIL for order
1027 * <= 3, but that may not be true in other implementations.
1028 */
1029 do_retry = 0;
1030 if (!(gfp_mask & __GFP_NORETRY)) {
1031 if ((order <= 3) || (gfp_mask & __GFP_REPEAT))
1032 do_retry = 1;
1033 if (gfp_mask & __GFP_NOFAIL)
1034 do_retry = 1;
1035 }
1036 if (do_retry) {
1037 blk_congestion_wait(WRITE, HZ/50);
1038 goto rebalance;
1039 }
1040
1041nopage:
1042 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) {
1043 printk(KERN_WARNING "%s: page allocation failure."
1044 " order:%d, mode:0x%x\n",
1045 p->comm, order, gfp_mask);
1046 dump_stack();
Janet Morgan578c2fd2005-06-21 17:14:56 -07001047 show_mem();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001048 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001049got_pg:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001050 return page;
1051}
1052
1053EXPORT_SYMBOL(__alloc_pages);
1054
1055/*
1056 * Common helper functions.
1057 */
Al Virodd0fc662005-10-07 07:46:04 +01001058fastcall unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001059{
1060 struct page * page;
1061 page = alloc_pages(gfp_mask, order);
1062 if (!page)
1063 return 0;
1064 return (unsigned long) page_address(page);
1065}
1066
1067EXPORT_SYMBOL(__get_free_pages);
1068
Al Virodd0fc662005-10-07 07:46:04 +01001069fastcall unsigned long get_zeroed_page(gfp_t gfp_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001070{
1071 struct page * page;
1072
1073 /*
1074 * get_zeroed_page() returns a 32-bit address, which cannot represent
1075 * a highmem page
1076 */
Al Viro260b2362005-10-21 03:22:44 -04001077 BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001078
1079 page = alloc_pages(gfp_mask | __GFP_ZERO, 0);
1080 if (page)
1081 return (unsigned long) page_address(page);
1082 return 0;
1083}
1084
1085EXPORT_SYMBOL(get_zeroed_page);
1086
1087void __pagevec_free(struct pagevec *pvec)
1088{
1089 int i = pagevec_count(pvec);
1090
1091 while (--i >= 0)
1092 free_hot_cold_page(pvec->pages[i], pvec->cold);
1093}
1094
1095fastcall void __free_pages(struct page *page, unsigned int order)
1096{
Nick Pigginb5810032005-10-29 18:16:12 -07001097 if (put_page_testzero(page)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001098 if (order == 0)
1099 free_hot_page(page);
1100 else
1101 __free_pages_ok(page, order);
1102 }
1103}
1104
1105EXPORT_SYMBOL(__free_pages);
1106
1107fastcall void free_pages(unsigned long addr, unsigned int order)
1108{
1109 if (addr != 0) {
1110 BUG_ON(!virt_addr_valid((void *)addr));
1111 __free_pages(virt_to_page((void *)addr), order);
1112 }
1113}
1114
1115EXPORT_SYMBOL(free_pages);
1116
1117/*
1118 * Total amount of free (allocatable) RAM:
1119 */
1120unsigned int nr_free_pages(void)
1121{
1122 unsigned int sum = 0;
1123 struct zone *zone;
1124
1125 for_each_zone(zone)
1126 sum += zone->free_pages;
1127
1128 return sum;
1129}
1130
1131EXPORT_SYMBOL(nr_free_pages);
1132
1133#ifdef CONFIG_NUMA
1134unsigned int nr_free_pages_pgdat(pg_data_t *pgdat)
1135{
1136 unsigned int i, sum = 0;
1137
1138 for (i = 0; i < MAX_NR_ZONES; i++)
1139 sum += pgdat->node_zones[i].free_pages;
1140
1141 return sum;
1142}
1143#endif
1144
1145static unsigned int nr_free_zone_pages(int offset)
1146{
Martin J. Blighe310fd42005-07-29 22:59:18 -07001147 /* Just pick one node, since fallback list is circular */
1148 pg_data_t *pgdat = NODE_DATA(numa_node_id());
Linus Torvalds1da177e2005-04-16 15:20:36 -07001149 unsigned int sum = 0;
1150
Martin J. Blighe310fd42005-07-29 22:59:18 -07001151 struct zonelist *zonelist = pgdat->node_zonelists + offset;
1152 struct zone **zonep = zonelist->zones;
1153 struct zone *zone;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154
Martin J. Blighe310fd42005-07-29 22:59:18 -07001155 for (zone = *zonep++; zone; zone = *zonep++) {
1156 unsigned long size = zone->present_pages;
1157 unsigned long high = zone->pages_high;
1158 if (size > high)
1159 sum += size - high;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001160 }
1161
1162 return sum;
1163}
1164
1165/*
1166 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
1167 */
1168unsigned int nr_free_buffer_pages(void)
1169{
Al Viroaf4ca452005-10-21 02:55:38 -04001170 return nr_free_zone_pages(gfp_zone(GFP_USER));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001171}
1172
1173/*
1174 * Amount of free RAM allocatable within all zones
1175 */
1176unsigned int nr_free_pagecache_pages(void)
1177{
Al Viroaf4ca452005-10-21 02:55:38 -04001178 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001179}
1180
1181#ifdef CONFIG_HIGHMEM
1182unsigned int nr_free_highpages (void)
1183{
1184 pg_data_t *pgdat;
1185 unsigned int pages = 0;
1186
1187 for_each_pgdat(pgdat)
1188 pages += pgdat->node_zones[ZONE_HIGHMEM].free_pages;
1189
1190 return pages;
1191}
1192#endif
1193
1194#ifdef CONFIG_NUMA
1195static void show_node(struct zone *zone)
1196{
1197 printk("Node %d ", zone->zone_pgdat->node_id);
1198}
1199#else
1200#define show_node(zone) do { } while (0)
1201#endif
1202
1203/*
1204 * Accumulate the page_state information across all CPUs.
1205 * The result is unavoidably approximate - it can change
1206 * during and after execution of this function.
1207 */
1208static DEFINE_PER_CPU(struct page_state, page_states) = {0};
1209
1210atomic_t nr_pagecache = ATOMIC_INIT(0);
1211EXPORT_SYMBOL(nr_pagecache);
1212#ifdef CONFIG_SMP
1213DEFINE_PER_CPU(long, nr_pagecache_local) = 0;
1214#endif
1215
Nick Piggina86b1f52006-01-06 00:11:00 -08001216static void __get_page_state(struct page_state *ret, int nr, cpumask_t *cpumask)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001217{
1218 int cpu = 0;
1219
Eric Dumazet88a2a4ac2006-02-04 23:27:36 -08001220 memset(ret, 0, nr * sizeof(unsigned long));
Andrew Morton84c20082006-01-08 01:00:28 -08001221 cpus_and(*cpumask, *cpumask, cpu_online_map);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001222
Martin Hicksc07e02d2005-09-03 15:55:11 -07001223 cpu = first_cpu(*cpumask);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001224 while (cpu < NR_CPUS) {
1225 unsigned long *in, *out, off;
1226
Eric Dumazet88a2a4ac2006-02-04 23:27:36 -08001227 if (!cpu_isset(cpu, *cpumask))
1228 continue;
1229
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230 in = (unsigned long *)&per_cpu(page_states, cpu);
1231
Martin Hicksc07e02d2005-09-03 15:55:11 -07001232 cpu = next_cpu(cpu, *cpumask);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001233
Eric Dumazet88a2a4ac2006-02-04 23:27:36 -08001234 if (likely(cpu < NR_CPUS))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001235 prefetch(&per_cpu(page_states, cpu));
1236
1237 out = (unsigned long *)ret;
1238 for (off = 0; off < nr; off++)
1239 *out++ += *in++;
1240 }
1241}
1242
Martin Hicksc07e02d2005-09-03 15:55:11 -07001243void get_page_state_node(struct page_state *ret, int node)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244{
1245 int nr;
Martin Hicksc07e02d2005-09-03 15:55:11 -07001246 cpumask_t mask = node_to_cpumask(node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001247
1248 nr = offsetof(struct page_state, GET_PAGE_STATE_LAST);
1249 nr /= sizeof(unsigned long);
1250
Martin Hicksc07e02d2005-09-03 15:55:11 -07001251 __get_page_state(ret, nr+1, &mask);
1252}
1253
1254void get_page_state(struct page_state *ret)
1255{
1256 int nr;
1257 cpumask_t mask = CPU_MASK_ALL;
1258
1259 nr = offsetof(struct page_state, GET_PAGE_STATE_LAST);
1260 nr /= sizeof(unsigned long);
1261
1262 __get_page_state(ret, nr + 1, &mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263}
1264
1265void get_full_page_state(struct page_state *ret)
1266{
Martin Hicksc07e02d2005-09-03 15:55:11 -07001267 cpumask_t mask = CPU_MASK_ALL;
1268
1269 __get_page_state(ret, sizeof(*ret) / sizeof(unsigned long), &mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001270}
1271
Nick Piggina74609f2006-01-06 00:11:20 -08001272unsigned long read_page_state_offset(unsigned long offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001273{
1274 unsigned long ret = 0;
1275 int cpu;
1276
Andrew Morton84c20082006-01-08 01:00:28 -08001277 for_each_online_cpu(cpu) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001278 unsigned long in;
1279
1280 in = (unsigned long)&per_cpu(page_states, cpu) + offset;
1281 ret += *((unsigned long *)in);
1282 }
1283 return ret;
1284}
1285
Nick Piggina74609f2006-01-06 00:11:20 -08001286void __mod_page_state_offset(unsigned long offset, unsigned long delta)
1287{
1288 void *ptr;
1289
1290 ptr = &__get_cpu_var(page_states);
1291 *(unsigned long *)(ptr + offset) += delta;
1292}
1293EXPORT_SYMBOL(__mod_page_state_offset);
1294
1295void mod_page_state_offset(unsigned long offset, unsigned long delta)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001296{
1297 unsigned long flags;
Nick Piggina74609f2006-01-06 00:11:20 -08001298 void *ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001299
1300 local_irq_save(flags);
1301 ptr = &__get_cpu_var(page_states);
Nick Piggina74609f2006-01-06 00:11:20 -08001302 *(unsigned long *)(ptr + offset) += delta;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001303 local_irq_restore(flags);
1304}
Nick Piggina74609f2006-01-06 00:11:20 -08001305EXPORT_SYMBOL(mod_page_state_offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001306
1307void __get_zone_counts(unsigned long *active, unsigned long *inactive,
1308 unsigned long *free, struct pglist_data *pgdat)
1309{
1310 struct zone *zones = pgdat->node_zones;
1311 int i;
1312
1313 *active = 0;
1314 *inactive = 0;
1315 *free = 0;
1316 for (i = 0; i < MAX_NR_ZONES; i++) {
1317 *active += zones[i].nr_active;
1318 *inactive += zones[i].nr_inactive;
1319 *free += zones[i].free_pages;
1320 }
1321}
1322
1323void get_zone_counts(unsigned long *active,
1324 unsigned long *inactive, unsigned long *free)
1325{
1326 struct pglist_data *pgdat;
1327
1328 *active = 0;
1329 *inactive = 0;
1330 *free = 0;
1331 for_each_pgdat(pgdat) {
1332 unsigned long l, m, n;
1333 __get_zone_counts(&l, &m, &n, pgdat);
1334 *active += l;
1335 *inactive += m;
1336 *free += n;
1337 }
1338}
1339
1340void si_meminfo(struct sysinfo *val)
1341{
1342 val->totalram = totalram_pages;
1343 val->sharedram = 0;
1344 val->freeram = nr_free_pages();
1345 val->bufferram = nr_blockdev_pages();
1346#ifdef CONFIG_HIGHMEM
1347 val->totalhigh = totalhigh_pages;
1348 val->freehigh = nr_free_highpages();
1349#else
1350 val->totalhigh = 0;
1351 val->freehigh = 0;
1352#endif
1353 val->mem_unit = PAGE_SIZE;
1354}
1355
1356EXPORT_SYMBOL(si_meminfo);
1357
1358#ifdef CONFIG_NUMA
1359void si_meminfo_node(struct sysinfo *val, int nid)
1360{
1361 pg_data_t *pgdat = NODE_DATA(nid);
1362
1363 val->totalram = pgdat->node_present_pages;
1364 val->freeram = nr_free_pages_pgdat(pgdat);
1365 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
1366 val->freehigh = pgdat->node_zones[ZONE_HIGHMEM].free_pages;
1367 val->mem_unit = PAGE_SIZE;
1368}
1369#endif
1370
1371#define K(x) ((x) << (PAGE_SHIFT-10))
1372
1373/*
1374 * Show free area list (used inside shift_scroll-lock stuff)
1375 * We also calculate the percentage fragmentation. We do this by counting the
1376 * memory on each free list with the exception of the first item on the list.
1377 */
1378void show_free_areas(void)
1379{
1380 struct page_state ps;
1381 int cpu, temperature;
1382 unsigned long active;
1383 unsigned long inactive;
1384 unsigned long free;
1385 struct zone *zone;
1386
1387 for_each_zone(zone) {
1388 show_node(zone);
1389 printk("%s per-cpu:", zone->name);
1390
Con Kolivasf3fe6512006-01-06 00:11:15 -08001391 if (!populated_zone(zone)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001392 printk(" empty\n");
1393 continue;
1394 } else
1395 printk("\n");
1396
Dave Jones6b482c62005-11-10 15:45:56 -05001397 for_each_online_cpu(cpu) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001398 struct per_cpu_pageset *pageset;
1399
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001400 pageset = zone_pcp(zone, cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001401
1402 for (temperature = 0; temperature < 2; temperature++)
Nick Piggin2d92c5c2006-01-06 00:10:59 -08001403 printk("cpu %d %s: high %d, batch %d used:%d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001404 cpu,
1405 temperature ? "cold" : "hot",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001406 pageset->pcp[temperature].high,
Christoph Lameter4ae7c032005-06-21 17:14:57 -07001407 pageset->pcp[temperature].batch,
1408 pageset->pcp[temperature].count);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001409 }
1410 }
1411
1412 get_page_state(&ps);
1413 get_zone_counts(&active, &inactive, &free);
1414
Denis Vlasenkoc0d62212005-06-21 17:15:14 -07001415 printk("Free pages: %11ukB (%ukB HighMem)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001416 K(nr_free_pages()),
1417 K(nr_free_highpages()));
1418
1419 printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu "
1420 "unstable:%lu free:%u slab:%lu mapped:%lu pagetables:%lu\n",
1421 active,
1422 inactive,
1423 ps.nr_dirty,
1424 ps.nr_writeback,
1425 ps.nr_unstable,
1426 nr_free_pages(),
1427 ps.nr_slab,
1428 ps.nr_mapped,
1429 ps.nr_page_table_pages);
1430
1431 for_each_zone(zone) {
1432 int i;
1433
1434 show_node(zone);
1435 printk("%s"
1436 " free:%lukB"
1437 " min:%lukB"
1438 " low:%lukB"
1439 " high:%lukB"
1440 " active:%lukB"
1441 " inactive:%lukB"
1442 " present:%lukB"
1443 " pages_scanned:%lu"
1444 " all_unreclaimable? %s"
1445 "\n",
1446 zone->name,
1447 K(zone->free_pages),
1448 K(zone->pages_min),
1449 K(zone->pages_low),
1450 K(zone->pages_high),
1451 K(zone->nr_active),
1452 K(zone->nr_inactive),
1453 K(zone->present_pages),
1454 zone->pages_scanned,
1455 (zone->all_unreclaimable ? "yes" : "no")
1456 );
1457 printk("lowmem_reserve[]:");
1458 for (i = 0; i < MAX_NR_ZONES; i++)
1459 printk(" %lu", zone->lowmem_reserve[i]);
1460 printk("\n");
1461 }
1462
1463 for_each_zone(zone) {
1464 unsigned long nr, flags, order, total = 0;
1465
1466 show_node(zone);
1467 printk("%s: ", zone->name);
Con Kolivasf3fe6512006-01-06 00:11:15 -08001468 if (!populated_zone(zone)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001469 printk("empty\n");
1470 continue;
1471 }
1472
1473 spin_lock_irqsave(&zone->lock, flags);
1474 for (order = 0; order < MAX_ORDER; order++) {
1475 nr = zone->free_area[order].nr_free;
1476 total += nr << order;
1477 printk("%lu*%lukB ", nr, K(1UL) << order);
1478 }
1479 spin_unlock_irqrestore(&zone->lock, flags);
1480 printk("= %lukB\n", K(total));
1481 }
1482
1483 show_swap_cache_info();
1484}
1485
1486/*
1487 * Builds allocation fallback zone lists.
Christoph Lameter1a932052006-01-06 00:11:16 -08001488 *
1489 * Add all populated zones of a node to the zonelist.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001490 */
Christoph Lameter1a932052006-01-06 00:11:16 -08001491static int __init build_zonelists_node(pg_data_t *pgdat,
Christoph Lameter070f8032006-01-06 00:11:19 -08001492 struct zonelist *zonelist, int nr_zones, int zone_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001493{
Christoph Lameter1a932052006-01-06 00:11:16 -08001494 struct zone *zone;
1495
Christoph Lameter070f8032006-01-06 00:11:19 -08001496 BUG_ON(zone_type > ZONE_HIGHMEM);
Christoph Lameter02a68a52006-01-06 00:11:18 -08001497
1498 do {
Christoph Lameter070f8032006-01-06 00:11:19 -08001499 zone = pgdat->node_zones + zone_type;
Christoph Lameter1a932052006-01-06 00:11:16 -08001500 if (populated_zone(zone)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001501#ifndef CONFIG_HIGHMEM
Christoph Lameter070f8032006-01-06 00:11:19 -08001502 BUG_ON(zone_type > ZONE_NORMAL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001503#endif
Christoph Lameter070f8032006-01-06 00:11:19 -08001504 zonelist->zones[nr_zones++] = zone;
1505 check_highest_zone(zone_type);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001506 }
Christoph Lameter070f8032006-01-06 00:11:19 -08001507 zone_type--;
Christoph Lameter02a68a52006-01-06 00:11:18 -08001508
Christoph Lameter070f8032006-01-06 00:11:19 -08001509 } while (zone_type >= 0);
1510 return nr_zones;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001511}
1512
Al Viro260b2362005-10-21 03:22:44 -04001513static inline int highest_zone(int zone_bits)
1514{
1515 int res = ZONE_NORMAL;
1516 if (zone_bits & (__force int)__GFP_HIGHMEM)
1517 res = ZONE_HIGHMEM;
Andi Kleena2f1b422005-11-05 17:25:53 +01001518 if (zone_bits & (__force int)__GFP_DMA32)
1519 res = ZONE_DMA32;
Al Viro260b2362005-10-21 03:22:44 -04001520 if (zone_bits & (__force int)__GFP_DMA)
1521 res = ZONE_DMA;
1522 return res;
1523}
1524
Linus Torvalds1da177e2005-04-16 15:20:36 -07001525#ifdef CONFIG_NUMA
1526#define MAX_NODE_LOAD (num_online_nodes())
1527static int __initdata node_load[MAX_NUMNODES];
1528/**
Pavel Pisa4dc3b162005-05-01 08:59:25 -07001529 * find_next_best_node - find the next node that should appear in a given node's fallback list
Linus Torvalds1da177e2005-04-16 15:20:36 -07001530 * @node: node whose fallback list we're appending
1531 * @used_node_mask: nodemask_t of already used nodes
1532 *
1533 * We use a number of factors to determine which is the next node that should
1534 * appear on a given node's fallback list. The node should not have appeared
1535 * already in @node's fallback list, and it should be the next closest node
1536 * according to the distance array (which contains arbitrary distance values
1537 * from each node to each node in the system), and should also prefer nodes
1538 * with no CPUs, since presumably they'll have very little allocation pressure
1539 * on them otherwise.
1540 * It returns -1 if no node is found.
1541 */
1542static int __init find_next_best_node(int node, nodemask_t *used_node_mask)
1543{
Linus Torvalds4cf808e2006-02-17 20:38:21 +01001544 int n, val;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001545 int min_val = INT_MAX;
1546 int best_node = -1;
1547
Linus Torvalds4cf808e2006-02-17 20:38:21 +01001548 /* Use the local node if we haven't already */
1549 if (!node_isset(node, *used_node_mask)) {
1550 node_set(node, *used_node_mask);
1551 return node;
1552 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001553
Linus Torvalds4cf808e2006-02-17 20:38:21 +01001554 for_each_online_node(n) {
1555 cpumask_t tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001556
1557 /* Don't want a node to appear more than once */
1558 if (node_isset(n, *used_node_mask))
1559 continue;
1560
Linus Torvalds1da177e2005-04-16 15:20:36 -07001561 /* Use the distance array to find the distance */
1562 val = node_distance(node, n);
1563
Linus Torvalds4cf808e2006-02-17 20:38:21 +01001564 /* Penalize nodes under us ("prefer the next node") */
1565 val += (n < node);
1566
Linus Torvalds1da177e2005-04-16 15:20:36 -07001567 /* Give preference to headless and unused nodes */
1568 tmp = node_to_cpumask(n);
1569 if (!cpus_empty(tmp))
1570 val += PENALTY_FOR_NODE_WITH_CPUS;
1571
1572 /* Slight preference for less loaded node */
1573 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
1574 val += node_load[n];
1575
1576 if (val < min_val) {
1577 min_val = val;
1578 best_node = n;
1579 }
1580 }
1581
1582 if (best_node >= 0)
1583 node_set(best_node, *used_node_mask);
1584
1585 return best_node;
1586}
1587
1588static void __init build_zonelists(pg_data_t *pgdat)
1589{
1590 int i, j, k, node, local_node;
1591 int prev_node, load;
1592 struct zonelist *zonelist;
1593 nodemask_t used_mask;
1594
1595 /* initialize zonelists */
1596 for (i = 0; i < GFP_ZONETYPES; i++) {
1597 zonelist = pgdat->node_zonelists + i;
1598 zonelist->zones[0] = NULL;
1599 }
1600
1601 /* NUMA-aware ordering of nodes */
1602 local_node = pgdat->node_id;
1603 load = num_online_nodes();
1604 prev_node = local_node;
1605 nodes_clear(used_mask);
1606 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
Christoph Lameter9eeff232006-01-18 17:42:31 -08001607 int distance = node_distance(local_node, node);
1608
1609 /*
1610 * If another node is sufficiently far away then it is better
1611 * to reclaim pages in a zone before going off node.
1612 */
1613 if (distance > RECLAIM_DISTANCE)
1614 zone_reclaim_mode = 1;
1615
Linus Torvalds1da177e2005-04-16 15:20:36 -07001616 /*
1617 * We don't want to pressure a particular node.
1618 * So adding penalty to the first node in same
1619 * distance group to make it round-robin.
1620 */
Christoph Lameter9eeff232006-01-18 17:42:31 -08001621
1622 if (distance != node_distance(local_node, prev_node))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001623 node_load[node] += load;
1624 prev_node = node;
1625 load--;
1626 for (i = 0; i < GFP_ZONETYPES; i++) {
1627 zonelist = pgdat->node_zonelists + i;
1628 for (j = 0; zonelist->zones[j] != NULL; j++);
1629
Al Viro260b2362005-10-21 03:22:44 -04001630 k = highest_zone(i);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001631
1632 j = build_zonelists_node(NODE_DATA(node), zonelist, j, k);
1633 zonelist->zones[j] = NULL;
1634 }
1635 }
1636}
1637
1638#else /* CONFIG_NUMA */
1639
1640static void __init build_zonelists(pg_data_t *pgdat)
1641{
1642 int i, j, k, node, local_node;
1643
1644 local_node = pgdat->node_id;
1645 for (i = 0; i < GFP_ZONETYPES; i++) {
1646 struct zonelist *zonelist;
1647
1648 zonelist = pgdat->node_zonelists + i;
1649
1650 j = 0;
Al Viro260b2362005-10-21 03:22:44 -04001651 k = highest_zone(i);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001652 j = build_zonelists_node(pgdat, zonelist, j, k);
1653 /*
1654 * Now we build the zonelist so that it contains the zones
1655 * of all the other nodes.
1656 * We don't want to pressure a particular node, so when
1657 * building the zones for node N, we make sure that the
1658 * zones coming right after the local ones are those from
1659 * node N+1 (modulo N)
1660 */
1661 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
1662 if (!node_online(node))
1663 continue;
1664 j = build_zonelists_node(NODE_DATA(node), zonelist, j, k);
1665 }
1666 for (node = 0; node < local_node; node++) {
1667 if (!node_online(node))
1668 continue;
1669 j = build_zonelists_node(NODE_DATA(node), zonelist, j, k);
1670 }
1671
1672 zonelist->zones[j] = NULL;
1673 }
1674}
1675
1676#endif /* CONFIG_NUMA */
1677
1678void __init build_all_zonelists(void)
1679{
1680 int i;
1681
1682 for_each_online_node(i)
1683 build_zonelists(NODE_DATA(i));
1684 printk("Built %i zonelists\n", num_online_nodes());
1685 cpuset_init_current_mems_allowed();
1686}
1687
1688/*
1689 * Helper functions to size the waitqueue hash table.
1690 * Essentially these want to choose hash table sizes sufficiently
1691 * large so that collisions trying to wait on pages are rare.
1692 * But in fact, the number of active page waitqueues on typical
1693 * systems is ridiculously low, less than 200. So this is even
1694 * conservative, even though it seems large.
1695 *
1696 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
1697 * waitqueues, i.e. the size of the waitq table given the number of pages.
1698 */
1699#define PAGES_PER_WAITQUEUE 256
1700
1701static inline unsigned long wait_table_size(unsigned long pages)
1702{
1703 unsigned long size = 1;
1704
1705 pages /= PAGES_PER_WAITQUEUE;
1706
1707 while (size < pages)
1708 size <<= 1;
1709
1710 /*
1711 * Once we have dozens or even hundreds of threads sleeping
1712 * on IO we've got bigger problems than wait queue collision.
1713 * Limit the size of the wait table to a reasonable size.
1714 */
1715 size = min(size, 4096UL);
1716
1717 return max(size, 4UL);
1718}
1719
1720/*
1721 * This is an integer logarithm so that shifts can be used later
1722 * to extract the more random high bits from the multiplicative
1723 * hash function before the remainder is taken.
1724 */
1725static inline unsigned long wait_table_bits(unsigned long size)
1726{
1727 return ffz(~size);
1728}
1729
1730#define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
1731
1732static void __init calculate_zone_totalpages(struct pglist_data *pgdat,
1733 unsigned long *zones_size, unsigned long *zholes_size)
1734{
1735 unsigned long realtotalpages, totalpages = 0;
1736 int i;
1737
1738 for (i = 0; i < MAX_NR_ZONES; i++)
1739 totalpages += zones_size[i];
1740 pgdat->node_spanned_pages = totalpages;
1741
1742 realtotalpages = totalpages;
1743 if (zholes_size)
1744 for (i = 0; i < MAX_NR_ZONES; i++)
1745 realtotalpages -= zholes_size[i];
1746 pgdat->node_present_pages = realtotalpages;
1747 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, realtotalpages);
1748}
1749
1750
1751/*
1752 * Initially all pages are reserved - free ones are freed
1753 * up by free_all_bootmem() once the early boot process is
1754 * done. Non-atomic initialization, single-pass.
1755 */
Matt Tolentinoc09b4242006-01-17 07:03:44 +01001756void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001757 unsigned long start_pfn)
1758{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001759 struct page *page;
Andy Whitcroft29751f62005-06-23 00:08:00 -07001760 unsigned long end_pfn = start_pfn + size;
1761 unsigned long pfn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001762
Greg Ungerercbe8dd42006-01-12 01:05:24 -08001763 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
Andy Whitcroftd41dee32005-06-23 00:07:54 -07001764 if (!early_pfn_valid(pfn))
1765 continue;
1766 page = pfn_to_page(pfn);
1767 set_page_links(page, zone, nid, pfn);
Nick Pigginb5810032005-10-29 18:16:12 -07001768 set_page_count(page, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001769 reset_page_mapcount(page);
1770 SetPageReserved(page);
1771 INIT_LIST_HEAD(&page->lru);
1772#ifdef WANT_PAGE_VIRTUAL
1773 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1774 if (!is_highmem_idx(zone))
Bob Picco3212c6b2005-06-27 14:36:28 -07001775 set_page_address(page, __va(pfn << PAGE_SHIFT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001776#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001777 }
1778}
1779
1780void zone_init_free_lists(struct pglist_data *pgdat, struct zone *zone,
1781 unsigned long size)
1782{
1783 int order;
1784 for (order = 0; order < MAX_ORDER ; order++) {
1785 INIT_LIST_HEAD(&zone->free_area[order].free_list);
1786 zone->free_area[order].nr_free = 0;
1787 }
1788}
1789
Andy Whitcroftd41dee32005-06-23 00:07:54 -07001790#define ZONETABLE_INDEX(x, zone_nr) ((x << ZONES_SHIFT) | zone_nr)
1791void zonetable_add(struct zone *zone, int nid, int zid, unsigned long pfn,
1792 unsigned long size)
1793{
1794 unsigned long snum = pfn_to_section_nr(pfn);
1795 unsigned long end = pfn_to_section_nr(pfn + size);
1796
1797 if (FLAGS_HAS_NODE)
1798 zone_table[ZONETABLE_INDEX(nid, zid)] = zone;
1799 else
1800 for (; snum <= end; snum++)
1801 zone_table[ZONETABLE_INDEX(snum, zid)] = zone;
1802}
1803
Linus Torvalds1da177e2005-04-16 15:20:36 -07001804#ifndef __HAVE_ARCH_MEMMAP_INIT
1805#define memmap_init(size, nid, zone, start_pfn) \
1806 memmap_init_zone((size), (nid), (zone), (start_pfn))
1807#endif
1808
Ashok Raj6292d9a2006-02-01 03:04:44 -08001809static int __cpuinit zone_batchsize(struct zone *zone)
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001810{
1811 int batch;
1812
1813 /*
1814 * The per-cpu-pages pools are set to around 1000th of the
Seth, Rohitba56e912005-10-29 18:15:47 -07001815 * size of the zone. But no more than 1/2 of a meg.
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001816 *
1817 * OK, so we don't know how big the cache is. So guess.
1818 */
1819 batch = zone->present_pages / 1024;
Seth, Rohitba56e912005-10-29 18:15:47 -07001820 if (batch * PAGE_SIZE > 512 * 1024)
1821 batch = (512 * 1024) / PAGE_SIZE;
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001822 batch /= 4; /* We effectively *= 4 below */
1823 if (batch < 1)
1824 batch = 1;
1825
1826 /*
Nick Piggin0ceaacc2005-12-04 13:55:25 +11001827 * Clamp the batch to a 2^n - 1 value. Having a power
1828 * of 2 value was found to be more likely to have
1829 * suboptimal cache aliasing properties in some cases.
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001830 *
Nick Piggin0ceaacc2005-12-04 13:55:25 +11001831 * For example if 2 tasks are alternately allocating
1832 * batches of pages, one task can end up with a lot
1833 * of pages of one half of the possible page colors
1834 * and the other with pages of the other colors.
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001835 */
Nick Piggin0ceaacc2005-12-04 13:55:25 +11001836 batch = (1 << (fls(batch + batch/2)-1)) - 1;
Seth, Rohitba56e912005-10-29 18:15:47 -07001837
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001838 return batch;
1839}
1840
Christoph Lameter2caaad42005-06-21 17:15:00 -07001841inline void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
1842{
1843 struct per_cpu_pages *pcp;
1844
Magnus Damm1c6fe942005-10-26 01:58:59 -07001845 memset(p, 0, sizeof(*p));
1846
Christoph Lameter2caaad42005-06-21 17:15:00 -07001847 pcp = &p->pcp[0]; /* hot */
1848 pcp->count = 0;
Christoph Lameter2caaad42005-06-21 17:15:00 -07001849 pcp->high = 6 * batch;
1850 pcp->batch = max(1UL, 1 * batch);
1851 INIT_LIST_HEAD(&pcp->list);
1852
1853 pcp = &p->pcp[1]; /* cold*/
1854 pcp->count = 0;
Christoph Lameter2caaad42005-06-21 17:15:00 -07001855 pcp->high = 2 * batch;
Seth, Rohite46a5e22005-10-29 18:15:48 -07001856 pcp->batch = max(1UL, batch/2);
Christoph Lameter2caaad42005-06-21 17:15:00 -07001857 INIT_LIST_HEAD(&pcp->list);
1858}
1859
Rohit Seth8ad4b1f2006-01-08 01:00:40 -08001860/*
1861 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
1862 * to the value high for the pageset p.
1863 */
1864
1865static void setup_pagelist_highmark(struct per_cpu_pageset *p,
1866 unsigned long high)
1867{
1868 struct per_cpu_pages *pcp;
1869
1870 pcp = &p->pcp[0]; /* hot list */
1871 pcp->high = high;
1872 pcp->batch = max(1UL, high/4);
1873 if ((high/4) > (PAGE_SHIFT * 8))
1874 pcp->batch = PAGE_SHIFT * 8;
1875}
1876
1877
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001878#ifdef CONFIG_NUMA
1879/*
Christoph Lameter2caaad42005-06-21 17:15:00 -07001880 * Boot pageset table. One per cpu which is going to be used for all
1881 * zones and all nodes. The parameters will be set in such a way
1882 * that an item put on a list will immediately be handed over to
1883 * the buddy list. This is safe since pageset manipulation is done
1884 * with interrupts disabled.
1885 *
1886 * Some NUMA counter updates may also be caught by the boot pagesets.
Christoph Lameterb7c84c62005-06-22 20:26:07 -07001887 *
1888 * The boot_pagesets must be kept even after bootup is complete for
1889 * unused processors and/or zones. They do play a role for bootstrapping
1890 * hotplugged processors.
1891 *
1892 * zoneinfo_show() and maybe other functions do
1893 * not check if the processor is online before following the pageset pointer.
1894 * Other parts of the kernel may not check if the zone is available.
Christoph Lameter2caaad42005-06-21 17:15:00 -07001895 */
Eric Dumazet88a2a4ac2006-02-04 23:27:36 -08001896static struct per_cpu_pageset boot_pageset[NR_CPUS];
Christoph Lameter2caaad42005-06-21 17:15:00 -07001897
1898/*
1899 * Dynamically allocate memory for the
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001900 * per cpu pageset array in struct zone.
1901 */
Ashok Raj6292d9a2006-02-01 03:04:44 -08001902static int __cpuinit process_zones(int cpu)
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001903{
1904 struct zone *zone, *dzone;
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001905
1906 for_each_zone(zone) {
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001907
Nick Piggin23316bc2006-01-08 01:00:41 -08001908 zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset),
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001909 GFP_KERNEL, cpu_to_node(cpu));
Nick Piggin23316bc2006-01-08 01:00:41 -08001910 if (!zone_pcp(zone, cpu))
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001911 goto bad;
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001912
Nick Piggin23316bc2006-01-08 01:00:41 -08001913 setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone));
Rohit Seth8ad4b1f2006-01-08 01:00:40 -08001914
1915 if (percpu_pagelist_fraction)
1916 setup_pagelist_highmark(zone_pcp(zone, cpu),
1917 (zone->present_pages / percpu_pagelist_fraction));
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001918 }
1919
1920 return 0;
1921bad:
1922 for_each_zone(dzone) {
1923 if (dzone == zone)
1924 break;
Nick Piggin23316bc2006-01-08 01:00:41 -08001925 kfree(zone_pcp(dzone, cpu));
1926 zone_pcp(dzone, cpu) = NULL;
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001927 }
1928 return -ENOMEM;
1929}
1930
1931static inline void free_zone_pagesets(int cpu)
1932{
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001933 struct zone *zone;
1934
1935 for_each_zone(zone) {
1936 struct per_cpu_pageset *pset = zone_pcp(zone, cpu);
1937
1938 zone_pcp(zone, cpu) = NULL;
1939 kfree(pset);
1940 }
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001941}
1942
Ashok Raj6292d9a2006-02-01 03:04:44 -08001943static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb,
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001944 unsigned long action,
1945 void *hcpu)
1946{
1947 int cpu = (long)hcpu;
1948 int ret = NOTIFY_OK;
1949
1950 switch (action) {
1951 case CPU_UP_PREPARE:
1952 if (process_zones(cpu))
1953 ret = NOTIFY_BAD;
1954 break;
Andi Kleenb0d41692005-11-05 17:25:53 +01001955 case CPU_UP_CANCELED:
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001956 case CPU_DEAD:
1957 free_zone_pagesets(cpu);
1958 break;
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001959 default:
1960 break;
1961 }
1962 return ret;
1963}
1964
1965static struct notifier_block pageset_notifier =
1966 { &pageset_cpuup_callback, NULL, 0 };
1967
Al Viro78d99552005-12-15 09:18:25 +00001968void __init setup_per_cpu_pageset(void)
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001969{
1970 int err;
1971
1972 /* Initialize per_cpu_pageset for cpu 0.
1973 * A cpuup callback will do this for every cpu
1974 * as it comes online
1975 */
1976 err = process_zones(smp_processor_id());
1977 BUG_ON(err);
1978 register_cpu_notifier(&pageset_notifier);
1979}
1980
1981#endif
1982
Matt Tolentinoc09b4242006-01-17 07:03:44 +01001983static __meminit
Dave Hansened8ece22005-10-29 18:16:50 -07001984void zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
1985{
1986 int i;
1987 struct pglist_data *pgdat = zone->zone_pgdat;
1988
1989 /*
1990 * The per-page waitqueue mechanism uses hashed waitqueues
1991 * per zone.
1992 */
1993 zone->wait_table_size = wait_table_size(zone_size_pages);
1994 zone->wait_table_bits = wait_table_bits(zone->wait_table_size);
1995 zone->wait_table = (wait_queue_head_t *)
1996 alloc_bootmem_node(pgdat, zone->wait_table_size
1997 * sizeof(wait_queue_head_t));
1998
1999 for(i = 0; i < zone->wait_table_size; ++i)
2000 init_waitqueue_head(zone->wait_table + i);
2001}
2002
Matt Tolentinoc09b4242006-01-17 07:03:44 +01002003static __meminit void zone_pcp_init(struct zone *zone)
Dave Hansened8ece22005-10-29 18:16:50 -07002004{
2005 int cpu;
2006 unsigned long batch = zone_batchsize(zone);
2007
2008 for (cpu = 0; cpu < NR_CPUS; cpu++) {
2009#ifdef CONFIG_NUMA
2010 /* Early boot. Slab allocator not functional yet */
Nick Piggin23316bc2006-01-08 01:00:41 -08002011 zone_pcp(zone, cpu) = &boot_pageset[cpu];
Dave Hansened8ece22005-10-29 18:16:50 -07002012 setup_pageset(&boot_pageset[cpu],0);
2013#else
2014 setup_pageset(zone_pcp(zone,cpu), batch);
2015#endif
2016 }
2017 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n",
2018 zone->name, zone->present_pages, batch);
2019}
2020
Matt Tolentinoc09b4242006-01-17 07:03:44 +01002021static __meminit void init_currently_empty_zone(struct zone *zone,
Dave Hansened8ece22005-10-29 18:16:50 -07002022 unsigned long zone_start_pfn, unsigned long size)
2023{
2024 struct pglist_data *pgdat = zone->zone_pgdat;
2025
2026 zone_wait_table_init(zone, size);
2027 pgdat->nr_zones = zone_idx(zone) + 1;
2028
2029 zone->zone_mem_map = pfn_to_page(zone_start_pfn);
2030 zone->zone_start_pfn = zone_start_pfn;
2031
2032 memmap_init(size, pgdat->node_id, zone_idx(zone), zone_start_pfn);
2033
2034 zone_init_free_lists(pgdat, zone, zone->spanned_pages);
2035}
2036
Linus Torvalds1da177e2005-04-16 15:20:36 -07002037/*
2038 * Set up the zone data structures:
2039 * - mark all pages reserved
2040 * - mark all memory queues empty
2041 * - clear the memory bitmaps
2042 */
2043static void __init free_area_init_core(struct pglist_data *pgdat,
2044 unsigned long *zones_size, unsigned long *zholes_size)
2045{
Dave Hansened8ece22005-10-29 18:16:50 -07002046 unsigned long j;
2047 int nid = pgdat->node_id;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002048 unsigned long zone_start_pfn = pgdat->node_start_pfn;
2049
Dave Hansen208d54e2005-10-29 18:16:52 -07002050 pgdat_resize_init(pgdat);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002051 pgdat->nr_zones = 0;
2052 init_waitqueue_head(&pgdat->kswapd_wait);
2053 pgdat->kswapd_max_order = 0;
2054
2055 for (j = 0; j < MAX_NR_ZONES; j++) {
2056 struct zone *zone = pgdat->node_zones + j;
2057 unsigned long size, realsize;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002058
Linus Torvalds1da177e2005-04-16 15:20:36 -07002059 realsize = size = zones_size[j];
2060 if (zholes_size)
2061 realsize -= zholes_size[j];
2062
Andi Kleena2f1b422005-11-05 17:25:53 +01002063 if (j < ZONE_HIGHMEM)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002064 nr_kernel_pages += realsize;
2065 nr_all_pages += realsize;
2066
2067 zone->spanned_pages = size;
2068 zone->present_pages = realsize;
2069 zone->name = zone_names[j];
2070 spin_lock_init(&zone->lock);
2071 spin_lock_init(&zone->lru_lock);
Dave Hansenbdc8cb92005-10-29 18:16:53 -07002072 zone_seqlock_init(zone);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002073 zone->zone_pgdat = pgdat;
2074 zone->free_pages = 0;
2075
2076 zone->temp_priority = zone->prev_priority = DEF_PRIORITY;
2077
Dave Hansened8ece22005-10-29 18:16:50 -07002078 zone_pcp_init(zone);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002079 INIT_LIST_HEAD(&zone->active_list);
2080 INIT_LIST_HEAD(&zone->inactive_list);
2081 zone->nr_scan_active = 0;
2082 zone->nr_scan_inactive = 0;
2083 zone->nr_active = 0;
2084 zone->nr_inactive = 0;
Martin Hicks53e9a612005-09-03 15:54:51 -07002085 atomic_set(&zone->reclaim_in_progress, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002086 if (!size)
2087 continue;
2088
Andy Whitcroftd41dee32005-06-23 00:07:54 -07002089 zonetable_add(zone, nid, j, zone_start_pfn, size);
Dave Hansened8ece22005-10-29 18:16:50 -07002090 init_currently_empty_zone(zone, zone_start_pfn, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002091 zone_start_pfn += size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002092 }
2093}
2094
2095static void __init alloc_node_mem_map(struct pglist_data *pgdat)
2096{
Linus Torvalds1da177e2005-04-16 15:20:36 -07002097 /* Skip empty nodes */
2098 if (!pgdat->node_spanned_pages)
2099 return;
2100
Andy Whitcroftd41dee32005-06-23 00:07:54 -07002101#ifdef CONFIG_FLAT_NODE_MEM_MAP
Linus Torvalds1da177e2005-04-16 15:20:36 -07002102 /* ia64 gets its own node_mem_map, before this, without bootmem */
2103 if (!pgdat->node_mem_map) {
Andy Whitcroftd41dee32005-06-23 00:07:54 -07002104 unsigned long size;
2105 struct page *map;
2106
Linus Torvalds1da177e2005-04-16 15:20:36 -07002107 size = (pgdat->node_spanned_pages + 1) * sizeof(struct page);
Dave Hansen6f167ec2005-06-23 00:07:39 -07002108 map = alloc_remap(pgdat->node_id, size);
2109 if (!map)
2110 map = alloc_bootmem_node(pgdat, size);
2111 pgdat->node_mem_map = map;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002112 }
Andy Whitcroftd41dee32005-06-23 00:07:54 -07002113#ifdef CONFIG_FLATMEM
Linus Torvalds1da177e2005-04-16 15:20:36 -07002114 /*
2115 * With no DISCONTIG, the global mem_map is just set as node 0's
2116 */
2117 if (pgdat == NODE_DATA(0))
2118 mem_map = NODE_DATA(0)->node_mem_map;
2119#endif
Andy Whitcroftd41dee32005-06-23 00:07:54 -07002120#endif /* CONFIG_FLAT_NODE_MEM_MAP */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002121}
2122
2123void __init free_area_init_node(int nid, struct pglist_data *pgdat,
2124 unsigned long *zones_size, unsigned long node_start_pfn,
2125 unsigned long *zholes_size)
2126{
2127 pgdat->node_id = nid;
2128 pgdat->node_start_pfn = node_start_pfn;
2129 calculate_zone_totalpages(pgdat, zones_size, zholes_size);
2130
2131 alloc_node_mem_map(pgdat);
2132
2133 free_area_init_core(pgdat, zones_size, zholes_size);
2134}
2135
Dave Hansen93b75042005-06-23 00:07:47 -07002136#ifndef CONFIG_NEED_MULTIPLE_NODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07002137static bootmem_data_t contig_bootmem_data;
2138struct pglist_data contig_page_data = { .bdata = &contig_bootmem_data };
2139
2140EXPORT_SYMBOL(contig_page_data);
Dave Hansen93b75042005-06-23 00:07:47 -07002141#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002142
2143void __init free_area_init(unsigned long *zones_size)
2144{
Dave Hansen93b75042005-06-23 00:07:47 -07002145 free_area_init_node(0, NODE_DATA(0), zones_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002146 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
2147}
Linus Torvalds1da177e2005-04-16 15:20:36 -07002148
2149#ifdef CONFIG_PROC_FS
2150
2151#include <linux/seq_file.h>
2152
2153static void *frag_start(struct seq_file *m, loff_t *pos)
2154{
2155 pg_data_t *pgdat;
2156 loff_t node = *pos;
2157
2158 for (pgdat = pgdat_list; pgdat && node; pgdat = pgdat->pgdat_next)
2159 --node;
2160
2161 return pgdat;
2162}
2163
2164static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
2165{
2166 pg_data_t *pgdat = (pg_data_t *)arg;
2167
2168 (*pos)++;
2169 return pgdat->pgdat_next;
2170}
2171
2172static void frag_stop(struct seq_file *m, void *arg)
2173{
2174}
2175
2176/*
2177 * This walks the free areas for each zone.
2178 */
2179static int frag_show(struct seq_file *m, void *arg)
2180{
2181 pg_data_t *pgdat = (pg_data_t *)arg;
2182 struct zone *zone;
2183 struct zone *node_zones = pgdat->node_zones;
2184 unsigned long flags;
2185 int order;
2186
2187 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
Con Kolivasf3fe6512006-01-06 00:11:15 -08002188 if (!populated_zone(zone))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002189 continue;
2190
2191 spin_lock_irqsave(&zone->lock, flags);
2192 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
2193 for (order = 0; order < MAX_ORDER; ++order)
2194 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
2195 spin_unlock_irqrestore(&zone->lock, flags);
2196 seq_putc(m, '\n');
2197 }
2198 return 0;
2199}
2200
2201struct seq_operations fragmentation_op = {
2202 .start = frag_start,
2203 .next = frag_next,
2204 .stop = frag_stop,
2205 .show = frag_show,
2206};
2207
Nikita Danilov295ab932005-06-21 17:14:38 -07002208/*
2209 * Output information about zones in @pgdat.
2210 */
2211static int zoneinfo_show(struct seq_file *m, void *arg)
2212{
2213 pg_data_t *pgdat = arg;
2214 struct zone *zone;
2215 struct zone *node_zones = pgdat->node_zones;
2216 unsigned long flags;
2217
2218 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; zone++) {
2219 int i;
2220
Con Kolivasf3fe6512006-01-06 00:11:15 -08002221 if (!populated_zone(zone))
Nikita Danilov295ab932005-06-21 17:14:38 -07002222 continue;
2223
2224 spin_lock_irqsave(&zone->lock, flags);
2225 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
2226 seq_printf(m,
2227 "\n pages free %lu"
2228 "\n min %lu"
2229 "\n low %lu"
2230 "\n high %lu"
2231 "\n active %lu"
2232 "\n inactive %lu"
2233 "\n scanned %lu (a: %lu i: %lu)"
2234 "\n spanned %lu"
2235 "\n present %lu",
2236 zone->free_pages,
2237 zone->pages_min,
2238 zone->pages_low,
2239 zone->pages_high,
2240 zone->nr_active,
2241 zone->nr_inactive,
2242 zone->pages_scanned,
2243 zone->nr_scan_active, zone->nr_scan_inactive,
2244 zone->spanned_pages,
2245 zone->present_pages);
2246 seq_printf(m,
2247 "\n protection: (%lu",
2248 zone->lowmem_reserve[0]);
2249 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
2250 seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
2251 seq_printf(m,
2252 ")"
2253 "\n pagesets");
Nick Piggin23316bc2006-01-08 01:00:41 -08002254 for_each_online_cpu(i) {
Nikita Danilov295ab932005-06-21 17:14:38 -07002255 struct per_cpu_pageset *pageset;
2256 int j;
2257
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07002258 pageset = zone_pcp(zone, i);
Nikita Danilov295ab932005-06-21 17:14:38 -07002259 for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {
2260 if (pageset->pcp[j].count)
2261 break;
2262 }
2263 if (j == ARRAY_SIZE(pageset->pcp))
2264 continue;
2265 for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {
2266 seq_printf(m,
2267 "\n cpu: %i pcp: %i"
2268 "\n count: %i"
Nikita Danilov295ab932005-06-21 17:14:38 -07002269 "\n high: %i"
2270 "\n batch: %i",
2271 i, j,
2272 pageset->pcp[j].count,
Nikita Danilov295ab932005-06-21 17:14:38 -07002273 pageset->pcp[j].high,
2274 pageset->pcp[j].batch);
2275 }
2276#ifdef CONFIG_NUMA
2277 seq_printf(m,
2278 "\n numa_hit: %lu"
2279 "\n numa_miss: %lu"
2280 "\n numa_foreign: %lu"
2281 "\n interleave_hit: %lu"
2282 "\n local_node: %lu"
2283 "\n other_node: %lu",
2284 pageset->numa_hit,
2285 pageset->numa_miss,
2286 pageset->numa_foreign,
2287 pageset->interleave_hit,
2288 pageset->local_node,
2289 pageset->other_node);
2290#endif
2291 }
2292 seq_printf(m,
2293 "\n all_unreclaimable: %u"
2294 "\n prev_priority: %i"
2295 "\n temp_priority: %i"
2296 "\n start_pfn: %lu",
2297 zone->all_unreclaimable,
2298 zone->prev_priority,
2299 zone->temp_priority,
2300 zone->zone_start_pfn);
2301 spin_unlock_irqrestore(&zone->lock, flags);
2302 seq_putc(m, '\n');
2303 }
2304 return 0;
2305}
2306
2307struct seq_operations zoneinfo_op = {
2308 .start = frag_start, /* iterate over all zones. The same as in
2309 * fragmentation. */
2310 .next = frag_next,
2311 .stop = frag_stop,
2312 .show = zoneinfo_show,
2313};
2314
Linus Torvalds1da177e2005-04-16 15:20:36 -07002315static char *vmstat_text[] = {
2316 "nr_dirty",
2317 "nr_writeback",
2318 "nr_unstable",
2319 "nr_page_table_pages",
2320 "nr_mapped",
2321 "nr_slab",
2322
2323 "pgpgin",
2324 "pgpgout",
2325 "pswpin",
2326 "pswpout",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002327
Nick Piggin9328b8f2006-01-06 00:11:10 -08002328 "pgalloc_high",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002329 "pgalloc_normal",
Nick Piggin9328b8f2006-01-06 00:11:10 -08002330 "pgalloc_dma32",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002331 "pgalloc_dma",
Nick Piggin9328b8f2006-01-06 00:11:10 -08002332
Linus Torvalds1da177e2005-04-16 15:20:36 -07002333 "pgfree",
2334 "pgactivate",
2335 "pgdeactivate",
2336
2337 "pgfault",
2338 "pgmajfault",
Nick Piggin9328b8f2006-01-06 00:11:10 -08002339
Linus Torvalds1da177e2005-04-16 15:20:36 -07002340 "pgrefill_high",
2341 "pgrefill_normal",
Nick Piggin9328b8f2006-01-06 00:11:10 -08002342 "pgrefill_dma32",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002343 "pgrefill_dma",
2344
2345 "pgsteal_high",
2346 "pgsteal_normal",
Nick Piggin9328b8f2006-01-06 00:11:10 -08002347 "pgsteal_dma32",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002348 "pgsteal_dma",
Nick Piggin9328b8f2006-01-06 00:11:10 -08002349
Linus Torvalds1da177e2005-04-16 15:20:36 -07002350 "pgscan_kswapd_high",
2351 "pgscan_kswapd_normal",
Nick Piggin9328b8f2006-01-06 00:11:10 -08002352 "pgscan_kswapd_dma32",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002353 "pgscan_kswapd_dma",
Nick Piggin9328b8f2006-01-06 00:11:10 -08002354
Linus Torvalds1da177e2005-04-16 15:20:36 -07002355 "pgscan_direct_high",
2356 "pgscan_direct_normal",
Nick Piggin9328b8f2006-01-06 00:11:10 -08002357 "pgscan_direct_dma32",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002358 "pgscan_direct_dma",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002359
Nick Piggin9328b8f2006-01-06 00:11:10 -08002360 "pginodesteal",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002361 "slabs_scanned",
2362 "kswapd_steal",
2363 "kswapd_inodesteal",
2364 "pageoutrun",
2365 "allocstall",
2366
2367 "pgrotated",
KAMEZAWA Hiroyukiedfbe2b2005-05-01 08:58:37 -07002368 "nr_bounce",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002369};
2370
2371static void *vmstat_start(struct seq_file *m, loff_t *pos)
2372{
2373 struct page_state *ps;
2374
2375 if (*pos >= ARRAY_SIZE(vmstat_text))
2376 return NULL;
2377
2378 ps = kmalloc(sizeof(*ps), GFP_KERNEL);
2379 m->private = ps;
2380 if (!ps)
2381 return ERR_PTR(-ENOMEM);
2382 get_full_page_state(ps);
2383 ps->pgpgin /= 2; /* sectors -> kbytes */
2384 ps->pgpgout /= 2;
2385 return (unsigned long *)ps + *pos;
2386}
2387
2388static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
2389{
2390 (*pos)++;
2391 if (*pos >= ARRAY_SIZE(vmstat_text))
2392 return NULL;
2393 return (unsigned long *)m->private + *pos;
2394}
2395
2396static int vmstat_show(struct seq_file *m, void *arg)
2397{
2398 unsigned long *l = arg;
2399 unsigned long off = l - (unsigned long *)m->private;
2400
2401 seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
2402 return 0;
2403}
2404
2405static void vmstat_stop(struct seq_file *m, void *arg)
2406{
2407 kfree(m->private);
2408 m->private = NULL;
2409}
2410
2411struct seq_operations vmstat_op = {
2412 .start = vmstat_start,
2413 .next = vmstat_next,
2414 .stop = vmstat_stop,
2415 .show = vmstat_show,
2416};
2417
2418#endif /* CONFIG_PROC_FS */
2419
2420#ifdef CONFIG_HOTPLUG_CPU
2421static int page_alloc_cpu_notify(struct notifier_block *self,
2422 unsigned long action, void *hcpu)
2423{
2424 int cpu = (unsigned long)hcpu;
2425 long *count;
2426 unsigned long *src, *dest;
2427
2428 if (action == CPU_DEAD) {
2429 int i;
2430
2431 /* Drain local pagecache count. */
2432 count = &per_cpu(nr_pagecache_local, cpu);
2433 atomic_add(*count, &nr_pagecache);
2434 *count = 0;
2435 local_irq_disable();
2436 __drain_pages(cpu);
2437
2438 /* Add dead cpu's page_states to our own. */
2439 dest = (unsigned long *)&__get_cpu_var(page_states);
2440 src = (unsigned long *)&per_cpu(page_states, cpu);
2441
2442 for (i = 0; i < sizeof(struct page_state)/sizeof(unsigned long);
2443 i++) {
2444 dest[i] += src[i];
2445 src[i] = 0;
2446 }
2447
2448 local_irq_enable();
2449 }
2450 return NOTIFY_OK;
2451}
2452#endif /* CONFIG_HOTPLUG_CPU */
2453
2454void __init page_alloc_init(void)
2455{
2456 hotcpu_notifier(page_alloc_cpu_notify, 0);
2457}
2458
2459/*
2460 * setup_per_zone_lowmem_reserve - called whenever
2461 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
2462 * has a correct pages reserved value, so an adequate number of
2463 * pages are left in the zone after a successful __alloc_pages().
2464 */
2465static void setup_per_zone_lowmem_reserve(void)
2466{
2467 struct pglist_data *pgdat;
2468 int j, idx;
2469
2470 for_each_pgdat(pgdat) {
2471 for (j = 0; j < MAX_NR_ZONES; j++) {
2472 struct zone *zone = pgdat->node_zones + j;
2473 unsigned long present_pages = zone->present_pages;
2474
2475 zone->lowmem_reserve[j] = 0;
2476
2477 for (idx = j-1; idx >= 0; idx--) {
2478 struct zone *lower_zone;
2479
2480 if (sysctl_lowmem_reserve_ratio[idx] < 1)
2481 sysctl_lowmem_reserve_ratio[idx] = 1;
2482
2483 lower_zone = pgdat->node_zones + idx;
2484 lower_zone->lowmem_reserve[j] = present_pages /
2485 sysctl_lowmem_reserve_ratio[idx];
2486 present_pages += lower_zone->present_pages;
2487 }
2488 }
2489 }
2490}
2491
2492/*
2493 * setup_per_zone_pages_min - called when min_free_kbytes changes. Ensures
2494 * that the pages_{min,low,high} values for each zone are set correctly
2495 * with respect to min_free_kbytes.
2496 */
Dave Hansen3947be12005-10-29 18:16:54 -07002497void setup_per_zone_pages_min(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002498{
2499 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
2500 unsigned long lowmem_pages = 0;
2501 struct zone *zone;
2502 unsigned long flags;
2503
2504 /* Calculate total number of !ZONE_HIGHMEM pages */
2505 for_each_zone(zone) {
2506 if (!is_highmem(zone))
2507 lowmem_pages += zone->present_pages;
2508 }
2509
2510 for_each_zone(zone) {
Nick Piggin669ed172005-11-13 16:06:45 -08002511 unsigned long tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002512 spin_lock_irqsave(&zone->lru_lock, flags);
Nick Piggin669ed172005-11-13 16:06:45 -08002513 tmp = (pages_min * zone->present_pages) / lowmem_pages;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002514 if (is_highmem(zone)) {
2515 /*
Nick Piggin669ed172005-11-13 16:06:45 -08002516 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
2517 * need highmem pages, so cap pages_min to a small
2518 * value here.
2519 *
2520 * The (pages_high-pages_low) and (pages_low-pages_min)
2521 * deltas controls asynch page reclaim, and so should
2522 * not be capped for highmem.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002523 */
2524 int min_pages;
2525
2526 min_pages = zone->present_pages / 1024;
2527 if (min_pages < SWAP_CLUSTER_MAX)
2528 min_pages = SWAP_CLUSTER_MAX;
2529 if (min_pages > 128)
2530 min_pages = 128;
2531 zone->pages_min = min_pages;
2532 } else {
Nick Piggin669ed172005-11-13 16:06:45 -08002533 /*
2534 * If it's a lowmem zone, reserve a number of pages
Linus Torvalds1da177e2005-04-16 15:20:36 -07002535 * proportionate to the zone's size.
2536 */
Nick Piggin669ed172005-11-13 16:06:45 -08002537 zone->pages_min = tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002538 }
2539
Nick Piggin669ed172005-11-13 16:06:45 -08002540 zone->pages_low = zone->pages_min + tmp / 4;
2541 zone->pages_high = zone->pages_min + tmp / 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002542 spin_unlock_irqrestore(&zone->lru_lock, flags);
2543 }
2544}
2545
2546/*
2547 * Initialise min_free_kbytes.
2548 *
2549 * For small machines we want it small (128k min). For large machines
2550 * we want it large (64MB max). But it is not linear, because network
2551 * bandwidth does not increase linearly with machine size. We use
2552 *
2553 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
2554 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
2555 *
2556 * which yields
2557 *
2558 * 16MB: 512k
2559 * 32MB: 724k
2560 * 64MB: 1024k
2561 * 128MB: 1448k
2562 * 256MB: 2048k
2563 * 512MB: 2896k
2564 * 1024MB: 4096k
2565 * 2048MB: 5792k
2566 * 4096MB: 8192k
2567 * 8192MB: 11584k
2568 * 16384MB: 16384k
2569 */
2570static int __init init_per_zone_pages_min(void)
2571{
2572 unsigned long lowmem_kbytes;
2573
2574 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
2575
2576 min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
2577 if (min_free_kbytes < 128)
2578 min_free_kbytes = 128;
2579 if (min_free_kbytes > 65536)
2580 min_free_kbytes = 65536;
2581 setup_per_zone_pages_min();
2582 setup_per_zone_lowmem_reserve();
2583 return 0;
2584}
2585module_init(init_per_zone_pages_min)
2586
2587/*
2588 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
2589 * that we can call two helper functions whenever min_free_kbytes
2590 * changes.
2591 */
2592int min_free_kbytes_sysctl_handler(ctl_table *table, int write,
2593 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
2594{
2595 proc_dointvec(table, write, file, buffer, length, ppos);
2596 setup_per_zone_pages_min();
2597 return 0;
2598}
2599
2600/*
2601 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
2602 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
2603 * whenever sysctl_lowmem_reserve_ratio changes.
2604 *
2605 * The reserve ratio obviously has absolutely no relation with the
2606 * pages_min watermarks. The lowmem reserve ratio can only make sense
2607 * if in function of the boot time zone sizes.
2608 */
2609int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
2610 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
2611{
2612 proc_dointvec_minmax(table, write, file, buffer, length, ppos);
2613 setup_per_zone_lowmem_reserve();
2614 return 0;
2615}
2616
Rohit Seth8ad4b1f2006-01-08 01:00:40 -08002617/*
2618 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
2619 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
2620 * can have before it gets flushed back to buddy allocator.
2621 */
2622
2623int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
2624 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
2625{
2626 struct zone *zone;
2627 unsigned int cpu;
2628 int ret;
2629
2630 ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
2631 if (!write || (ret == -EINVAL))
2632 return ret;
2633 for_each_zone(zone) {
2634 for_each_online_cpu(cpu) {
2635 unsigned long high;
2636 high = zone->present_pages / percpu_pagelist_fraction;
2637 setup_pagelist_highmark(zone_pcp(zone, cpu), high);
2638 }
2639 }
2640 return 0;
2641}
2642
Linus Torvalds1da177e2005-04-16 15:20:36 -07002643__initdata int hashdist = HASHDIST_DEFAULT;
2644
2645#ifdef CONFIG_NUMA
2646static int __init set_hashdist(char *str)
2647{
2648 if (!str)
2649 return 0;
2650 hashdist = simple_strtoul(str, &str, 0);
2651 return 1;
2652}
2653__setup("hashdist=", set_hashdist);
2654#endif
2655
2656/*
2657 * allocate a large system hash table from bootmem
2658 * - it is assumed that the hash table must contain an exact power-of-2
2659 * quantity of entries
2660 * - limit is the number of hash buckets, not the total allocation size
2661 */
2662void *__init alloc_large_system_hash(const char *tablename,
2663 unsigned long bucketsize,
2664 unsigned long numentries,
2665 int scale,
2666 int flags,
2667 unsigned int *_hash_shift,
2668 unsigned int *_hash_mask,
2669 unsigned long limit)
2670{
2671 unsigned long long max = limit;
2672 unsigned long log2qty, size;
2673 void *table = NULL;
2674
2675 /* allow the kernel cmdline to have a say */
2676 if (!numentries) {
2677 /* round applicable memory size up to nearest megabyte */
2678 numentries = (flags & HASH_HIGHMEM) ? nr_all_pages : nr_kernel_pages;
2679 numentries += (1UL << (20 - PAGE_SHIFT)) - 1;
2680 numentries >>= 20 - PAGE_SHIFT;
2681 numentries <<= 20 - PAGE_SHIFT;
2682
2683 /* limit to 1 bucket per 2^scale bytes of low memory */
2684 if (scale > PAGE_SHIFT)
2685 numentries >>= (scale - PAGE_SHIFT);
2686 else
2687 numentries <<= (PAGE_SHIFT - scale);
2688 }
2689 /* rounded up to nearest power of 2 in size */
2690 numentries = 1UL << (long_log2(numentries) + 1);
2691
2692 /* limit allocation size to 1/16 total memory by default */
2693 if (max == 0) {
2694 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
2695 do_div(max, bucketsize);
2696 }
2697
2698 if (numentries > max)
2699 numentries = max;
2700
2701 log2qty = long_log2(numentries);
2702
2703 do {
2704 size = bucketsize << log2qty;
2705 if (flags & HASH_EARLY)
2706 table = alloc_bootmem(size);
2707 else if (hashdist)
2708 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
2709 else {
2710 unsigned long order;
2711 for (order = 0; ((1UL << order) << PAGE_SHIFT) < size; order++)
2712 ;
2713 table = (void*) __get_free_pages(GFP_ATOMIC, order);
2714 }
2715 } while (!table && size > PAGE_SIZE && --log2qty);
2716
2717 if (!table)
2718 panic("Failed to allocate %s hash table\n", tablename);
2719
2720 printk("%s hash table entries: %d (order: %d, %lu bytes)\n",
2721 tablename,
2722 (1U << log2qty),
2723 long_log2(size) - PAGE_SHIFT,
2724 size);
2725
2726 if (_hash_shift)
2727 *_hash_shift = log2qty;
2728 if (_hash_mask)
2729 *_hash_mask = (1 << log2qty) - 1;
2730
2731 return table;
2732}