blob: a95e72d7f9452e28a6ea77b34f8a483a321392e4 [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>
25#include <linux/module.h>
26#include <linux/suspend.h>
27#include <linux/pagevec.h>
28#include <linux/blkdev.h>
29#include <linux/slab.h>
30#include <linux/notifier.h>
31#include <linux/topology.h>
32#include <linux/sysctl.h>
33#include <linux/cpu.h>
34#include <linux/cpuset.h>
35#include <linux/nodemask.h>
36#include <linux/vmalloc.h>
37
38#include <asm/tlbflush.h>
39#include "internal.h"
40
41/*
42 * MCD - HACK: Find somewhere to initialize this EARLY, or make this
43 * initializer cleaner
44 */
45nodemask_t node_online_map = { { [0] = 1UL } };
Dean Nelson7223a932005-03-23 19:00:00 -070046EXPORT_SYMBOL(node_online_map);
Linus Torvalds1da177e2005-04-16 15:20:36 -070047nodemask_t node_possible_map = NODE_MASK_ALL;
Dean Nelson7223a932005-03-23 19:00:00 -070048EXPORT_SYMBOL(node_possible_map);
Linus Torvalds1da177e2005-04-16 15:20:36 -070049struct pglist_data *pgdat_list;
50unsigned long totalram_pages;
51unsigned long totalhigh_pages;
52long nr_swap_pages;
53
54/*
55 * results with 256, 32 in the lowmem_reserve sysctl:
56 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
57 * 1G machine -> (16M dma, 784M normal, 224M high)
58 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
59 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
60 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
61 */
62int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { 256, 32 };
63
64EXPORT_SYMBOL(totalram_pages);
65EXPORT_SYMBOL(nr_swap_pages);
66
67/*
68 * Used by page_zone() to look up the address of the struct zone whose
69 * id is encoded in the upper bits of page->flags
70 */
71struct zone *zone_table[1 << (ZONES_SHIFT + NODES_SHIFT)];
72EXPORT_SYMBOL(zone_table);
73
Christoph Lametere7c8d5c2005-06-21 17:14:47 -070074#ifdef CONFIG_NUMA
75static struct per_cpu_pageset
76 pageset_table[MAX_NR_ZONES*MAX_NUMNODES*NR_CPUS] __initdata;
77#endif
78
Linus Torvalds1da177e2005-04-16 15:20:36 -070079static char *zone_names[MAX_NR_ZONES] = { "DMA", "Normal", "HighMem" };
80int min_free_kbytes = 1024;
81
82unsigned long __initdata nr_kernel_pages;
83unsigned long __initdata nr_all_pages;
84
85/*
86 * Temporary debugging check for pages not lying within a given zone.
87 */
88static int bad_range(struct zone *zone, struct page *page)
89{
90 if (page_to_pfn(page) >= zone->zone_start_pfn + zone->spanned_pages)
91 return 1;
92 if (page_to_pfn(page) < zone->zone_start_pfn)
93 return 1;
94#ifdef CONFIG_HOLES_IN_ZONE
95 if (!pfn_valid(page_to_pfn(page)))
96 return 1;
97#endif
98 if (zone != page_zone(page))
99 return 1;
100 return 0;
101}
102
103static void bad_page(const char *function, struct page *page)
104{
105 printk(KERN_EMERG "Bad page state at %s (in process '%s', page %p)\n",
106 function, current->comm, page);
107 printk(KERN_EMERG "flags:0x%0*lx mapping:%p mapcount:%d count:%d\n",
108 (int)(2*sizeof(page_flags_t)), (unsigned long)page->flags,
109 page->mapping, page_mapcount(page), page_count(page));
110 printk(KERN_EMERG "Backtrace:\n");
111 dump_stack();
112 printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n");
113 page->flags &= ~(1 << PG_private |
114 1 << PG_locked |
115 1 << PG_lru |
116 1 << PG_active |
117 1 << PG_dirty |
118 1 << PG_swapcache |
119 1 << PG_writeback);
120 set_page_count(page, 0);
121 reset_page_mapcount(page);
122 page->mapping = NULL;
123 tainted |= TAINT_BAD_PAGE;
124}
125
126#ifndef CONFIG_HUGETLB_PAGE
127#define prep_compound_page(page, order) do { } while (0)
128#define destroy_compound_page(page, order) do { } while (0)
129#else
130/*
131 * Higher-order pages are called "compound pages". They are structured thusly:
132 *
133 * The first PAGE_SIZE page is called the "head page".
134 *
135 * The remaining PAGE_SIZE pages are called "tail pages".
136 *
137 * All pages have PG_compound set. All pages have their ->private pointing at
138 * the head page (even the head page has this).
139 *
140 * The first tail page's ->mapping, if non-zero, holds the address of the
141 * compound page's put_page() function.
142 *
143 * The order of the allocation is stored in the first tail page's ->index
144 * This is only for debug at present. This usage means that zero-order pages
145 * may not be compound.
146 */
147static void prep_compound_page(struct page *page, unsigned long order)
148{
149 int i;
150 int nr_pages = 1 << order;
151
152 page[1].mapping = NULL;
153 page[1].index = order;
154 for (i = 0; i < nr_pages; i++) {
155 struct page *p = page + i;
156
157 SetPageCompound(p);
158 p->private = (unsigned long)page;
159 }
160}
161
162static void destroy_compound_page(struct page *page, unsigned long order)
163{
164 int i;
165 int nr_pages = 1 << order;
166
167 if (!PageCompound(page))
168 return;
169
170 if (page[1].index != order)
171 bad_page(__FUNCTION__, page);
172
173 for (i = 0; i < nr_pages; i++) {
174 struct page *p = page + i;
175
176 if (!PageCompound(p))
177 bad_page(__FUNCTION__, page);
178 if (p->private != (unsigned long)page)
179 bad_page(__FUNCTION__, page);
180 ClearPageCompound(p);
181 }
182}
183#endif /* CONFIG_HUGETLB_PAGE */
184
185/*
186 * function for dealing with page's order in buddy system.
187 * zone->lock is already acquired when we use these.
188 * So, we don't need atomic page->flags operations here.
189 */
190static inline unsigned long page_order(struct page *page) {
191 return page->private;
192}
193
194static inline void set_page_order(struct page *page, int order) {
195 page->private = order;
196 __SetPagePrivate(page);
197}
198
199static inline void rmv_page_order(struct page *page)
200{
201 __ClearPagePrivate(page);
202 page->private = 0;
203}
204
205/*
206 * Locate the struct page for both the matching buddy in our
207 * pair (buddy1) and the combined O(n+1) page they form (page).
208 *
209 * 1) Any buddy B1 will have an order O twin B2 which satisfies
210 * the following equation:
211 * B2 = B1 ^ (1 << O)
212 * For example, if the starting buddy (buddy2) is #8 its order
213 * 1 buddy is #10:
214 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
215 *
216 * 2) Any buddy B will have an order O+1 parent P which
217 * satisfies the following equation:
218 * P = B & ~(1 << O)
219 *
220 * Assumption: *_mem_map is contigious at least up to MAX_ORDER
221 */
222static inline struct page *
223__page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order)
224{
225 unsigned long buddy_idx = page_idx ^ (1 << order);
226
227 return page + (buddy_idx - page_idx);
228}
229
230static inline unsigned long
231__find_combined_index(unsigned long page_idx, unsigned int order)
232{
233 return (page_idx & ~(1 << order));
234}
235
236/*
237 * This function checks whether a page is free && is the buddy
238 * we can do coalesce a page and its buddy if
239 * (a) the buddy is free &&
240 * (b) the buddy is on the buddy system &&
241 * (c) a page and its buddy have the same order.
242 * for recording page's order, we use page->private and PG_private.
243 *
244 */
245static inline int page_is_buddy(struct page *page, int order)
246{
247 if (PagePrivate(page) &&
248 (page_order(page) == order) &&
249 !PageReserved(page) &&
250 page_count(page) == 0)
251 return 1;
252 return 0;
253}
254
255/*
256 * Freeing function for a buddy system allocator.
257 *
258 * The concept of a buddy system is to maintain direct-mapped table
259 * (containing bit values) for memory blocks of various "orders".
260 * The bottom level table contains the map for the smallest allocatable
261 * units of memory (here, pages), and each level above it describes
262 * pairs of units from the levels below, hence, "buddies".
263 * At a high level, all that happens here is marking the table entry
264 * at the bottom level available, and propagating the changes upward
265 * as necessary, plus some accounting needed to play nicely with other
266 * parts of the VM system.
267 * At each level, we keep a list of pages, which are heads of continuous
268 * free pages of length of (1 << order) and marked with PG_Private.Page's
269 * order is recorded in page->private field.
270 * So when we are allocating or freeing one, we can derive the state of the
271 * other. That is, if we allocate a small block, and both were
272 * free, the remainder of the region must be split into blocks.
273 * If a block is freed, and its buddy is also free, then this
274 * triggers coalescing into a block of larger size.
275 *
276 * -- wli
277 */
278
279static inline void __free_pages_bulk (struct page *page,
280 struct zone *zone, unsigned int order)
281{
282 unsigned long page_idx;
283 int order_size = 1 << order;
284
285 if (unlikely(order))
286 destroy_compound_page(page, order);
287
288 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
289
290 BUG_ON(page_idx & (order_size - 1));
291 BUG_ON(bad_range(zone, page));
292
293 zone->free_pages += order_size;
294 while (order < MAX_ORDER-1) {
295 unsigned long combined_idx;
296 struct free_area *area;
297 struct page *buddy;
298
299 combined_idx = __find_combined_index(page_idx, order);
300 buddy = __page_find_buddy(page, page_idx, order);
301
302 if (bad_range(zone, buddy))
303 break;
304 if (!page_is_buddy(buddy, order))
305 break; /* Move the buddy up one level. */
306 list_del(&buddy->lru);
307 area = zone->free_area + order;
308 area->nr_free--;
309 rmv_page_order(buddy);
310 page = page + (combined_idx - page_idx);
311 page_idx = combined_idx;
312 order++;
313 }
314 set_page_order(page, order);
315 list_add(&page->lru, &zone->free_area[order].free_list);
316 zone->free_area[order].nr_free++;
317}
318
319static inline void free_pages_check(const char *function, struct page *page)
320{
321 if ( page_mapcount(page) ||
322 page->mapping != NULL ||
323 page_count(page) != 0 ||
324 (page->flags & (
325 1 << PG_lru |
326 1 << PG_private |
327 1 << PG_locked |
328 1 << PG_active |
329 1 << PG_reclaim |
330 1 << PG_slab |
331 1 << PG_swapcache |
332 1 << PG_writeback )))
333 bad_page(function, page);
334 if (PageDirty(page))
335 ClearPageDirty(page);
336}
337
338/*
339 * Frees a list of pages.
340 * Assumes all pages on list are in same zone, and of same order.
341 * count is the number of pages to free, or 0 for all on the list.
342 *
343 * If the zone was previously in an "all pages pinned" state then look to
344 * see if this freeing clears that state.
345 *
346 * And clear the zone's pages_scanned counter, to hold off the "all pages are
347 * pinned" detection logic.
348 */
349static int
350free_pages_bulk(struct zone *zone, int count,
351 struct list_head *list, unsigned int order)
352{
353 unsigned long flags;
354 struct page *page = NULL;
355 int ret = 0;
356
357 spin_lock_irqsave(&zone->lock, flags);
358 zone->all_unreclaimable = 0;
359 zone->pages_scanned = 0;
360 while (!list_empty(list) && count--) {
361 page = list_entry(list->prev, struct page, lru);
362 /* have to delete it as __free_pages_bulk list manipulates */
363 list_del(&page->lru);
364 __free_pages_bulk(page, zone, order);
365 ret++;
366 }
367 spin_unlock_irqrestore(&zone->lock, flags);
368 return ret;
369}
370
371void __free_pages_ok(struct page *page, unsigned int order)
372{
373 LIST_HEAD(list);
374 int i;
375
376 arch_free_page(page, order);
377
378 mod_page_state(pgfree, 1 << order);
379
380#ifndef CONFIG_MMU
381 if (order > 0)
382 for (i = 1 ; i < (1 << order) ; ++i)
383 __put_page(page + i);
384#endif
385
386 for (i = 0 ; i < (1 << order) ; ++i)
387 free_pages_check(__FUNCTION__, page + i);
388 list_add(&page->lru, &list);
389 kernel_map_pages(page, 1<<order, 0);
390 free_pages_bulk(page_zone(page), 1, &list, order);
391}
392
393
394/*
395 * The order of subdivision here is critical for the IO subsystem.
396 * Please do not alter this order without good reasons and regression
397 * testing. Specifically, as large blocks of memory are subdivided,
398 * the order in which smaller blocks are delivered depends on the order
399 * they're subdivided in this function. This is the primary factor
400 * influencing the order in which pages are delivered to the IO
401 * subsystem according to empirical testing, and this is also justified
402 * by considering the behavior of a buddy system containing a single
403 * large block of memory acted on by a series of small allocations.
404 * This behavior is a critical factor in sglist merging's success.
405 *
406 * -- wli
407 */
408static inline struct page *
409expand(struct zone *zone, struct page *page,
410 int low, int high, struct free_area *area)
411{
412 unsigned long size = 1 << high;
413
414 while (high > low) {
415 area--;
416 high--;
417 size >>= 1;
418 BUG_ON(bad_range(zone, &page[size]));
419 list_add(&page[size].lru, &area->free_list);
420 area->nr_free++;
421 set_page_order(&page[size], high);
422 }
423 return page;
424}
425
426void set_page_refs(struct page *page, int order)
427{
428#ifdef CONFIG_MMU
429 set_page_count(page, 1);
430#else
431 int i;
432
433 /*
434 * We need to reference all the pages for this order, otherwise if
435 * anyone accesses one of the pages with (get/put) it will be freed.
436 * - eg: access_process_vm()
437 */
438 for (i = 0; i < (1 << order); i++)
439 set_page_count(page + i, 1);
440#endif /* CONFIG_MMU */
441}
442
443/*
444 * This page is about to be returned from the page allocator
445 */
446static void prep_new_page(struct page *page, int order)
447{
448 if (page->mapping || page_mapcount(page) ||
449 (page->flags & (
450 1 << PG_private |
451 1 << PG_locked |
452 1 << PG_lru |
453 1 << PG_active |
454 1 << PG_dirty |
455 1 << PG_reclaim |
456 1 << PG_swapcache |
457 1 << PG_writeback )))
458 bad_page(__FUNCTION__, page);
459
460 page->flags &= ~(1 << PG_uptodate | 1 << PG_error |
461 1 << PG_referenced | 1 << PG_arch_1 |
462 1 << PG_checked | 1 << PG_mappedtodisk);
463 page->private = 0;
464 set_page_refs(page, order);
465 kernel_map_pages(page, 1 << order, 1);
466}
467
468/*
469 * Do the hard work of removing an element from the buddy allocator.
470 * Call me with the zone->lock already held.
471 */
472static struct page *__rmqueue(struct zone *zone, unsigned int order)
473{
474 struct free_area * area;
475 unsigned int current_order;
476 struct page *page;
477
478 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
479 area = zone->free_area + current_order;
480 if (list_empty(&area->free_list))
481 continue;
482
483 page = list_entry(area->free_list.next, struct page, lru);
484 list_del(&page->lru);
485 rmv_page_order(page);
486 area->nr_free--;
487 zone->free_pages -= 1UL << order;
488 return expand(zone, page, order, current_order, area);
489 }
490
491 return NULL;
492}
493
494/*
495 * Obtain a specified number of elements from the buddy allocator, all under
496 * a single hold of the lock, for efficiency. Add them to the supplied list.
497 * Returns the number of new pages which were placed at *list.
498 */
499static int rmqueue_bulk(struct zone *zone, unsigned int order,
500 unsigned long count, struct list_head *list)
501{
502 unsigned long flags;
503 int i;
504 int allocated = 0;
505 struct page *page;
506
507 spin_lock_irqsave(&zone->lock, flags);
508 for (i = 0; i < count; ++i) {
509 page = __rmqueue(zone, order);
510 if (page == NULL)
511 break;
512 allocated++;
513 list_add_tail(&page->lru, list);
514 }
515 spin_unlock_irqrestore(&zone->lock, flags);
516 return allocated;
517}
518
Christoph Lameter4ae7c032005-06-21 17:14:57 -0700519#ifdef CONFIG_NUMA
520/* Called from the slab reaper to drain remote pagesets */
521void drain_remote_pages(void)
522{
523 struct zone *zone;
524 int i;
525 unsigned long flags;
526
527 local_irq_save(flags);
528 for_each_zone(zone) {
529 struct per_cpu_pageset *pset;
530
531 /* Do not drain local pagesets */
532 if (zone->zone_pgdat->node_id == numa_node_id())
533 continue;
534
535 pset = zone->pageset[smp_processor_id()];
536 for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) {
537 struct per_cpu_pages *pcp;
538
539 pcp = &pset->pcp[i];
540 if (pcp->count)
541 pcp->count -= free_pages_bulk(zone, pcp->count,
542 &pcp->list, 0);
543 }
544 }
545 local_irq_restore(flags);
546}
547#endif
548
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549#if defined(CONFIG_PM) || defined(CONFIG_HOTPLUG_CPU)
550static void __drain_pages(unsigned int cpu)
551{
552 struct zone *zone;
553 int i;
554
555 for_each_zone(zone) {
556 struct per_cpu_pageset *pset;
557
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700558 pset = zone_pcp(zone, cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) {
560 struct per_cpu_pages *pcp;
561
562 pcp = &pset->pcp[i];
563 pcp->count -= free_pages_bulk(zone, pcp->count,
564 &pcp->list, 0);
565 }
566 }
567}
568#endif /* CONFIG_PM || CONFIG_HOTPLUG_CPU */
569
570#ifdef CONFIG_PM
571
572void mark_free_pages(struct zone *zone)
573{
574 unsigned long zone_pfn, flags;
575 int order;
576 struct list_head *curr;
577
578 if (!zone->spanned_pages)
579 return;
580
581 spin_lock_irqsave(&zone->lock, flags);
582 for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
583 ClearPageNosaveFree(pfn_to_page(zone_pfn + zone->zone_start_pfn));
584
585 for (order = MAX_ORDER - 1; order >= 0; --order)
586 list_for_each(curr, &zone->free_area[order].free_list) {
587 unsigned long start_pfn, i;
588
589 start_pfn = page_to_pfn(list_entry(curr, struct page, lru));
590
591 for (i=0; i < (1<<order); i++)
592 SetPageNosaveFree(pfn_to_page(start_pfn+i));
593 }
594 spin_unlock_irqrestore(&zone->lock, flags);
595}
596
597/*
598 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
599 */
600void drain_local_pages(void)
601{
602 unsigned long flags;
603
604 local_irq_save(flags);
605 __drain_pages(smp_processor_id());
606 local_irq_restore(flags);
607}
608#endif /* CONFIG_PM */
609
610static void zone_statistics(struct zonelist *zonelist, struct zone *z)
611{
612#ifdef CONFIG_NUMA
613 unsigned long flags;
614 int cpu;
615 pg_data_t *pg = z->zone_pgdat;
616 pg_data_t *orig = zonelist->zones[0]->zone_pgdat;
617 struct per_cpu_pageset *p;
618
619 local_irq_save(flags);
620 cpu = smp_processor_id();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700621 p = zone_pcp(z,cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622 if (pg == orig) {
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700623 p->numa_hit++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 } else {
625 p->numa_miss++;
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700626 zone_pcp(zonelist->zones[0], cpu)->numa_foreign++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 }
628 if (pg == NODE_DATA(numa_node_id()))
629 p->local_node++;
630 else
631 p->other_node++;
632 local_irq_restore(flags);
633#endif
634}
635
636/*
637 * Free a 0-order page
638 */
639static void FASTCALL(free_hot_cold_page(struct page *page, int cold));
640static void fastcall free_hot_cold_page(struct page *page, int cold)
641{
642 struct zone *zone = page_zone(page);
643 struct per_cpu_pages *pcp;
644 unsigned long flags;
645
646 arch_free_page(page, 0);
647
648 kernel_map_pages(page, 1, 0);
649 inc_page_state(pgfree);
650 if (PageAnon(page))
651 page->mapping = NULL;
652 free_pages_check(__FUNCTION__, page);
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700653 pcp = &zone_pcp(zone, get_cpu())->pcp[cold];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654 local_irq_save(flags);
655 if (pcp->count >= pcp->high)
656 pcp->count -= free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
657 list_add(&page->lru, &pcp->list);
658 pcp->count++;
659 local_irq_restore(flags);
660 put_cpu();
661}
662
663void fastcall free_hot_page(struct page *page)
664{
665 free_hot_cold_page(page, 0);
666}
667
668void fastcall free_cold_page(struct page *page)
669{
670 free_hot_cold_page(page, 1);
671}
672
673static inline void prep_zero_page(struct page *page, int order, unsigned int __nocast gfp_flags)
674{
675 int i;
676
677 BUG_ON((gfp_flags & (__GFP_WAIT | __GFP_HIGHMEM)) == __GFP_HIGHMEM);
678 for(i = 0; i < (1 << order); i++)
679 clear_highpage(page + i);
680}
681
682/*
683 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
684 * we cheat by calling it from here, in the order > 0 path. Saves a branch
685 * or two.
686 */
687static struct page *
688buffered_rmqueue(struct zone *zone, int order, unsigned int __nocast gfp_flags)
689{
690 unsigned long flags;
691 struct page *page = NULL;
692 int cold = !!(gfp_flags & __GFP_COLD);
693
694 if (order == 0) {
695 struct per_cpu_pages *pcp;
696
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700697 pcp = &zone_pcp(zone, get_cpu())->pcp[cold];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 local_irq_save(flags);
699 if (pcp->count <= pcp->low)
700 pcp->count += rmqueue_bulk(zone, 0,
701 pcp->batch, &pcp->list);
702 if (pcp->count) {
703 page = list_entry(pcp->list.next, struct page, lru);
704 list_del(&page->lru);
705 pcp->count--;
706 }
707 local_irq_restore(flags);
708 put_cpu();
709 }
710
711 if (page == NULL) {
712 spin_lock_irqsave(&zone->lock, flags);
713 page = __rmqueue(zone, order);
714 spin_unlock_irqrestore(&zone->lock, flags);
715 }
716
717 if (page != NULL) {
718 BUG_ON(bad_range(zone, page));
719 mod_page_state_zone(zone, pgalloc, 1 << order);
720 prep_new_page(page, order);
721
722 if (gfp_flags & __GFP_ZERO)
723 prep_zero_page(page, order, gfp_flags);
724
725 if (order && (gfp_flags & __GFP_COMP))
726 prep_compound_page(page, order);
727 }
728 return page;
729}
730
731/*
732 * Return 1 if free pages are above 'mark'. This takes into account the order
733 * of the allocation.
734 */
735int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
736 int classzone_idx, int can_try_harder, int gfp_high)
737{
738 /* free_pages my go negative - that's OK */
739 long min = mark, free_pages = z->free_pages - (1 << order) + 1;
740 int o;
741
742 if (gfp_high)
743 min -= min / 2;
744 if (can_try_harder)
745 min -= min / 4;
746
747 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
748 return 0;
749 for (o = 0; o < order; o++) {
750 /* At the next order, this order's pages become unavailable */
751 free_pages -= z->free_area[o].nr_free << o;
752
753 /* Require fewer higher order pages to be free */
754 min >>= 1;
755
756 if (free_pages <= min)
757 return 0;
758 }
759 return 1;
760}
761
Martin Hicks753ee722005-06-21 17:14:41 -0700762static inline int
763should_reclaim_zone(struct zone *z, unsigned int gfp_mask)
764{
765 if (!z->reclaim_pages)
766 return 0;
Martin Hicks0c35bba2005-06-21 17:14:42 -0700767 if (gfp_mask & __GFP_NORECLAIM)
768 return 0;
Martin Hicks753ee722005-06-21 17:14:41 -0700769 return 1;
770}
771
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772/*
773 * This is the 'heart' of the zoned buddy allocator.
774 */
775struct page * fastcall
776__alloc_pages(unsigned int __nocast gfp_mask, unsigned int order,
777 struct zonelist *zonelist)
778{
779 const int wait = gfp_mask & __GFP_WAIT;
780 struct zone **zones, *z;
781 struct page *page;
782 struct reclaim_state reclaim_state;
783 struct task_struct *p = current;
784 int i;
785 int classzone_idx;
786 int do_retry;
787 int can_try_harder;
788 int did_some_progress;
789
790 might_sleep_if(wait);
791
792 /*
793 * The caller may dip into page reserves a bit more if the caller
794 * cannot run direct reclaim, or is the caller has realtime scheduling
795 * policy
796 */
797 can_try_harder = (unlikely(rt_task(p)) && !in_interrupt()) || !wait;
798
799 zones = zonelist->zones; /* the list of zones suitable for gfp_mask */
800
801 if (unlikely(zones[0] == NULL)) {
802 /* Should this ever happen?? */
803 return NULL;
804 }
805
806 classzone_idx = zone_idx(zones[0]);
807
Martin Hicks753ee722005-06-21 17:14:41 -0700808restart:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809 /* Go through the zonelist once, looking for a zone with enough free */
810 for (i = 0; (z = zones[i]) != NULL; i++) {
Martin Hicks753ee722005-06-21 17:14:41 -0700811 int do_reclaim = should_reclaim_zone(z, gfp_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700812
813 if (!cpuset_zone_allowed(z))
814 continue;
815
Martin Hicks753ee722005-06-21 17:14:41 -0700816 /*
817 * If the zone is to attempt early page reclaim then this loop
818 * will try to reclaim pages and check the watermark a second
819 * time before giving up and falling back to the next zone.
820 */
821zone_reclaim_retry:
822 if (!zone_watermark_ok(z, order, z->pages_low,
823 classzone_idx, 0, 0)) {
824 if (!do_reclaim)
825 continue;
826 else {
827 zone_reclaim(z, gfp_mask, order);
828 /* Only try reclaim once */
829 do_reclaim = 0;
830 goto zone_reclaim_retry;
831 }
832 }
833
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834 page = buffered_rmqueue(z, order, gfp_mask);
835 if (page)
836 goto got_pg;
837 }
838
839 for (i = 0; (z = zones[i]) != NULL; i++)
840 wakeup_kswapd(z, order);
841
842 /*
843 * Go through the zonelist again. Let __GFP_HIGH and allocations
844 * coming from realtime tasks to go deeper into reserves
845 *
846 * This is the last chance, in general, before the goto nopage.
847 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
848 */
849 for (i = 0; (z = zones[i]) != NULL; i++) {
850 if (!zone_watermark_ok(z, order, z->pages_min,
851 classzone_idx, can_try_harder,
852 gfp_mask & __GFP_HIGH))
853 continue;
854
855 if (wait && !cpuset_zone_allowed(z))
856 continue;
857
858 page = buffered_rmqueue(z, order, gfp_mask);
859 if (page)
860 goto got_pg;
861 }
862
863 /* This allocation should allow future memory freeing. */
Nick Pigginb84a35b2005-05-01 08:58:36 -0700864
865 if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE)))
866 && !in_interrupt()) {
867 if (!(gfp_mask & __GFP_NOMEMALLOC)) {
868 /* go through the zonelist yet again, ignoring mins */
869 for (i = 0; (z = zones[i]) != NULL; i++) {
870 if (!cpuset_zone_allowed(z))
871 continue;
872 page = buffered_rmqueue(z, order, gfp_mask);
873 if (page)
874 goto got_pg;
875 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876 }
877 goto nopage;
878 }
879
880 /* Atomic allocations - we can't balance anything */
881 if (!wait)
882 goto nopage;
883
884rebalance:
885 cond_resched();
886
887 /* We now go into synchronous reclaim */
888 p->flags |= PF_MEMALLOC;
889 reclaim_state.reclaimed_slab = 0;
890 p->reclaim_state = &reclaim_state;
891
Darren Hart1ad539b2005-06-21 17:14:53 -0700892 did_some_progress = try_to_free_pages(zones, gfp_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893
894 p->reclaim_state = NULL;
895 p->flags &= ~PF_MEMALLOC;
896
897 cond_resched();
898
899 if (likely(did_some_progress)) {
900 /*
901 * Go through the zonelist yet one more time, keep
902 * very high watermark here, this is only to catch
903 * a parallel oom killing, we must fail if we're still
904 * under heavy pressure.
905 */
906 for (i = 0; (z = zones[i]) != NULL; i++) {
907 if (!zone_watermark_ok(z, order, z->pages_min,
908 classzone_idx, can_try_harder,
909 gfp_mask & __GFP_HIGH))
910 continue;
911
912 if (!cpuset_zone_allowed(z))
913 continue;
914
915 page = buffered_rmqueue(z, order, gfp_mask);
916 if (page)
917 goto got_pg;
918 }
919 } else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
920 /*
921 * Go through the zonelist yet one more time, keep
922 * very high watermark here, this is only to catch
923 * a parallel oom killing, we must fail if we're still
924 * under heavy pressure.
925 */
926 for (i = 0; (z = zones[i]) != NULL; i++) {
927 if (!zone_watermark_ok(z, order, z->pages_high,
928 classzone_idx, 0, 0))
929 continue;
930
931 if (!cpuset_zone_allowed(z))
932 continue;
933
934 page = buffered_rmqueue(z, order, gfp_mask);
935 if (page)
936 goto got_pg;
937 }
938
939 out_of_memory(gfp_mask);
940 goto restart;
941 }
942
943 /*
944 * Don't let big-order allocations loop unless the caller explicitly
945 * requests that. Wait for some write requests to complete then retry.
946 *
947 * In this implementation, __GFP_REPEAT means __GFP_NOFAIL for order
948 * <= 3, but that may not be true in other implementations.
949 */
950 do_retry = 0;
951 if (!(gfp_mask & __GFP_NORETRY)) {
952 if ((order <= 3) || (gfp_mask & __GFP_REPEAT))
953 do_retry = 1;
954 if (gfp_mask & __GFP_NOFAIL)
955 do_retry = 1;
956 }
957 if (do_retry) {
958 blk_congestion_wait(WRITE, HZ/50);
959 goto rebalance;
960 }
961
962nopage:
963 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) {
964 printk(KERN_WARNING "%s: page allocation failure."
965 " order:%d, mode:0x%x\n",
966 p->comm, order, gfp_mask);
967 dump_stack();
Janet Morgan578c2fd2005-06-21 17:14:56 -0700968 show_mem();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969 }
970 return NULL;
971got_pg:
972 zone_statistics(zonelist, z);
973 return page;
974}
975
976EXPORT_SYMBOL(__alloc_pages);
977
978/*
979 * Common helper functions.
980 */
981fastcall unsigned long __get_free_pages(unsigned int __nocast gfp_mask, unsigned int order)
982{
983 struct page * page;
984 page = alloc_pages(gfp_mask, order);
985 if (!page)
986 return 0;
987 return (unsigned long) page_address(page);
988}
989
990EXPORT_SYMBOL(__get_free_pages);
991
992fastcall unsigned long get_zeroed_page(unsigned int __nocast gfp_mask)
993{
994 struct page * page;
995
996 /*
997 * get_zeroed_page() returns a 32-bit address, which cannot represent
998 * a highmem page
999 */
1000 BUG_ON(gfp_mask & __GFP_HIGHMEM);
1001
1002 page = alloc_pages(gfp_mask | __GFP_ZERO, 0);
1003 if (page)
1004 return (unsigned long) page_address(page);
1005 return 0;
1006}
1007
1008EXPORT_SYMBOL(get_zeroed_page);
1009
1010void __pagevec_free(struct pagevec *pvec)
1011{
1012 int i = pagevec_count(pvec);
1013
1014 while (--i >= 0)
1015 free_hot_cold_page(pvec->pages[i], pvec->cold);
1016}
1017
1018fastcall void __free_pages(struct page *page, unsigned int order)
1019{
1020 if (!PageReserved(page) && put_page_testzero(page)) {
1021 if (order == 0)
1022 free_hot_page(page);
1023 else
1024 __free_pages_ok(page, order);
1025 }
1026}
1027
1028EXPORT_SYMBOL(__free_pages);
1029
1030fastcall void free_pages(unsigned long addr, unsigned int order)
1031{
1032 if (addr != 0) {
1033 BUG_ON(!virt_addr_valid((void *)addr));
1034 __free_pages(virt_to_page((void *)addr), order);
1035 }
1036}
1037
1038EXPORT_SYMBOL(free_pages);
1039
1040/*
1041 * Total amount of free (allocatable) RAM:
1042 */
1043unsigned int nr_free_pages(void)
1044{
1045 unsigned int sum = 0;
1046 struct zone *zone;
1047
1048 for_each_zone(zone)
1049 sum += zone->free_pages;
1050
1051 return sum;
1052}
1053
1054EXPORT_SYMBOL(nr_free_pages);
1055
1056#ifdef CONFIG_NUMA
1057unsigned int nr_free_pages_pgdat(pg_data_t *pgdat)
1058{
1059 unsigned int i, sum = 0;
1060
1061 for (i = 0; i < MAX_NR_ZONES; i++)
1062 sum += pgdat->node_zones[i].free_pages;
1063
1064 return sum;
1065}
1066#endif
1067
1068static unsigned int nr_free_zone_pages(int offset)
1069{
1070 pg_data_t *pgdat;
1071 unsigned int sum = 0;
1072
1073 for_each_pgdat(pgdat) {
1074 struct zonelist *zonelist = pgdat->node_zonelists + offset;
1075 struct zone **zonep = zonelist->zones;
1076 struct zone *zone;
1077
1078 for (zone = *zonep++; zone; zone = *zonep++) {
1079 unsigned long size = zone->present_pages;
1080 unsigned long high = zone->pages_high;
1081 if (size > high)
1082 sum += size - high;
1083 }
1084 }
1085
1086 return sum;
1087}
1088
1089/*
1090 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
1091 */
1092unsigned int nr_free_buffer_pages(void)
1093{
1094 return nr_free_zone_pages(GFP_USER & GFP_ZONEMASK);
1095}
1096
1097/*
1098 * Amount of free RAM allocatable within all zones
1099 */
1100unsigned int nr_free_pagecache_pages(void)
1101{
1102 return nr_free_zone_pages(GFP_HIGHUSER & GFP_ZONEMASK);
1103}
1104
1105#ifdef CONFIG_HIGHMEM
1106unsigned int nr_free_highpages (void)
1107{
1108 pg_data_t *pgdat;
1109 unsigned int pages = 0;
1110
1111 for_each_pgdat(pgdat)
1112 pages += pgdat->node_zones[ZONE_HIGHMEM].free_pages;
1113
1114 return pages;
1115}
1116#endif
1117
1118#ifdef CONFIG_NUMA
1119static void show_node(struct zone *zone)
1120{
1121 printk("Node %d ", zone->zone_pgdat->node_id);
1122}
1123#else
1124#define show_node(zone) do { } while (0)
1125#endif
1126
1127/*
1128 * Accumulate the page_state information across all CPUs.
1129 * The result is unavoidably approximate - it can change
1130 * during and after execution of this function.
1131 */
1132static DEFINE_PER_CPU(struct page_state, page_states) = {0};
1133
1134atomic_t nr_pagecache = ATOMIC_INIT(0);
1135EXPORT_SYMBOL(nr_pagecache);
1136#ifdef CONFIG_SMP
1137DEFINE_PER_CPU(long, nr_pagecache_local) = 0;
1138#endif
1139
1140void __get_page_state(struct page_state *ret, int nr)
1141{
1142 int cpu = 0;
1143
1144 memset(ret, 0, sizeof(*ret));
1145
1146 cpu = first_cpu(cpu_online_map);
1147 while (cpu < NR_CPUS) {
1148 unsigned long *in, *out, off;
1149
1150 in = (unsigned long *)&per_cpu(page_states, cpu);
1151
1152 cpu = next_cpu(cpu, cpu_online_map);
1153
1154 if (cpu < NR_CPUS)
1155 prefetch(&per_cpu(page_states, cpu));
1156
1157 out = (unsigned long *)ret;
1158 for (off = 0; off < nr; off++)
1159 *out++ += *in++;
1160 }
1161}
1162
1163void get_page_state(struct page_state *ret)
1164{
1165 int nr;
1166
1167 nr = offsetof(struct page_state, GET_PAGE_STATE_LAST);
1168 nr /= sizeof(unsigned long);
1169
1170 __get_page_state(ret, nr + 1);
1171}
1172
1173void get_full_page_state(struct page_state *ret)
1174{
1175 __get_page_state(ret, sizeof(*ret) / sizeof(unsigned long));
1176}
1177
Benjamin LaHaisec2f29ea2005-06-21 17:14:55 -07001178unsigned long __read_page_state(unsigned long offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001179{
1180 unsigned long ret = 0;
1181 int cpu;
1182
1183 for_each_online_cpu(cpu) {
1184 unsigned long in;
1185
1186 in = (unsigned long)&per_cpu(page_states, cpu) + offset;
1187 ret += *((unsigned long *)in);
1188 }
1189 return ret;
1190}
1191
Benjamin LaHaise83e5d8f2005-06-21 17:14:54 -07001192void __mod_page_state(unsigned long offset, unsigned long delta)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001193{
1194 unsigned long flags;
1195 void* ptr;
1196
1197 local_irq_save(flags);
1198 ptr = &__get_cpu_var(page_states);
1199 *(unsigned long*)(ptr + offset) += delta;
1200 local_irq_restore(flags);
1201}
1202
1203EXPORT_SYMBOL(__mod_page_state);
1204
1205void __get_zone_counts(unsigned long *active, unsigned long *inactive,
1206 unsigned long *free, struct pglist_data *pgdat)
1207{
1208 struct zone *zones = pgdat->node_zones;
1209 int i;
1210
1211 *active = 0;
1212 *inactive = 0;
1213 *free = 0;
1214 for (i = 0; i < MAX_NR_ZONES; i++) {
1215 *active += zones[i].nr_active;
1216 *inactive += zones[i].nr_inactive;
1217 *free += zones[i].free_pages;
1218 }
1219}
1220
1221void get_zone_counts(unsigned long *active,
1222 unsigned long *inactive, unsigned long *free)
1223{
1224 struct pglist_data *pgdat;
1225
1226 *active = 0;
1227 *inactive = 0;
1228 *free = 0;
1229 for_each_pgdat(pgdat) {
1230 unsigned long l, m, n;
1231 __get_zone_counts(&l, &m, &n, pgdat);
1232 *active += l;
1233 *inactive += m;
1234 *free += n;
1235 }
1236}
1237
1238void si_meminfo(struct sysinfo *val)
1239{
1240 val->totalram = totalram_pages;
1241 val->sharedram = 0;
1242 val->freeram = nr_free_pages();
1243 val->bufferram = nr_blockdev_pages();
1244#ifdef CONFIG_HIGHMEM
1245 val->totalhigh = totalhigh_pages;
1246 val->freehigh = nr_free_highpages();
1247#else
1248 val->totalhigh = 0;
1249 val->freehigh = 0;
1250#endif
1251 val->mem_unit = PAGE_SIZE;
1252}
1253
1254EXPORT_SYMBOL(si_meminfo);
1255
1256#ifdef CONFIG_NUMA
1257void si_meminfo_node(struct sysinfo *val, int nid)
1258{
1259 pg_data_t *pgdat = NODE_DATA(nid);
1260
1261 val->totalram = pgdat->node_present_pages;
1262 val->freeram = nr_free_pages_pgdat(pgdat);
1263 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
1264 val->freehigh = pgdat->node_zones[ZONE_HIGHMEM].free_pages;
1265 val->mem_unit = PAGE_SIZE;
1266}
1267#endif
1268
1269#define K(x) ((x) << (PAGE_SHIFT-10))
1270
1271/*
1272 * Show free area list (used inside shift_scroll-lock stuff)
1273 * We also calculate the percentage fragmentation. We do this by counting the
1274 * memory on each free list with the exception of the first item on the list.
1275 */
1276void show_free_areas(void)
1277{
1278 struct page_state ps;
1279 int cpu, temperature;
1280 unsigned long active;
1281 unsigned long inactive;
1282 unsigned long free;
1283 struct zone *zone;
1284
1285 for_each_zone(zone) {
1286 show_node(zone);
1287 printk("%s per-cpu:", zone->name);
1288
1289 if (!zone->present_pages) {
1290 printk(" empty\n");
1291 continue;
1292 } else
1293 printk("\n");
1294
1295 for (cpu = 0; cpu < NR_CPUS; ++cpu) {
1296 struct per_cpu_pageset *pageset;
1297
1298 if (!cpu_possible(cpu))
1299 continue;
1300
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001301 pageset = zone_pcp(zone, cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001302
1303 for (temperature = 0; temperature < 2; temperature++)
Christoph Lameter4ae7c032005-06-21 17:14:57 -07001304 printk("cpu %d %s: low %d, high %d, batch %d used:%d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001305 cpu,
1306 temperature ? "cold" : "hot",
1307 pageset->pcp[temperature].low,
1308 pageset->pcp[temperature].high,
Christoph Lameter4ae7c032005-06-21 17:14:57 -07001309 pageset->pcp[temperature].batch,
1310 pageset->pcp[temperature].count);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001311 }
1312 }
1313
1314 get_page_state(&ps);
1315 get_zone_counts(&active, &inactive, &free);
1316
1317 printk("\nFree pages: %11ukB (%ukB HighMem)\n",
1318 K(nr_free_pages()),
1319 K(nr_free_highpages()));
1320
1321 printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu "
1322 "unstable:%lu free:%u slab:%lu mapped:%lu pagetables:%lu\n",
1323 active,
1324 inactive,
1325 ps.nr_dirty,
1326 ps.nr_writeback,
1327 ps.nr_unstable,
1328 nr_free_pages(),
1329 ps.nr_slab,
1330 ps.nr_mapped,
1331 ps.nr_page_table_pages);
1332
1333 for_each_zone(zone) {
1334 int i;
1335
1336 show_node(zone);
1337 printk("%s"
1338 " free:%lukB"
1339 " min:%lukB"
1340 " low:%lukB"
1341 " high:%lukB"
1342 " active:%lukB"
1343 " inactive:%lukB"
1344 " present:%lukB"
1345 " pages_scanned:%lu"
1346 " all_unreclaimable? %s"
1347 "\n",
1348 zone->name,
1349 K(zone->free_pages),
1350 K(zone->pages_min),
1351 K(zone->pages_low),
1352 K(zone->pages_high),
1353 K(zone->nr_active),
1354 K(zone->nr_inactive),
1355 K(zone->present_pages),
1356 zone->pages_scanned,
1357 (zone->all_unreclaimable ? "yes" : "no")
1358 );
1359 printk("lowmem_reserve[]:");
1360 for (i = 0; i < MAX_NR_ZONES; i++)
1361 printk(" %lu", zone->lowmem_reserve[i]);
1362 printk("\n");
1363 }
1364
1365 for_each_zone(zone) {
1366 unsigned long nr, flags, order, total = 0;
1367
1368 show_node(zone);
1369 printk("%s: ", zone->name);
1370 if (!zone->present_pages) {
1371 printk("empty\n");
1372 continue;
1373 }
1374
1375 spin_lock_irqsave(&zone->lock, flags);
1376 for (order = 0; order < MAX_ORDER; order++) {
1377 nr = zone->free_area[order].nr_free;
1378 total += nr << order;
1379 printk("%lu*%lukB ", nr, K(1UL) << order);
1380 }
1381 spin_unlock_irqrestore(&zone->lock, flags);
1382 printk("= %lukB\n", K(total));
1383 }
1384
1385 show_swap_cache_info();
1386}
1387
1388/*
1389 * Builds allocation fallback zone lists.
1390 */
1391static int __init build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist, int j, int k)
1392{
1393 switch (k) {
1394 struct zone *zone;
1395 default:
1396 BUG();
1397 case ZONE_HIGHMEM:
1398 zone = pgdat->node_zones + ZONE_HIGHMEM;
1399 if (zone->present_pages) {
1400#ifndef CONFIG_HIGHMEM
1401 BUG();
1402#endif
1403 zonelist->zones[j++] = zone;
1404 }
1405 case ZONE_NORMAL:
1406 zone = pgdat->node_zones + ZONE_NORMAL;
1407 if (zone->present_pages)
1408 zonelist->zones[j++] = zone;
1409 case ZONE_DMA:
1410 zone = pgdat->node_zones + ZONE_DMA;
1411 if (zone->present_pages)
1412 zonelist->zones[j++] = zone;
1413 }
1414
1415 return j;
1416}
1417
1418#ifdef CONFIG_NUMA
1419#define MAX_NODE_LOAD (num_online_nodes())
1420static int __initdata node_load[MAX_NUMNODES];
1421/**
Pavel Pisa4dc3b162005-05-01 08:59:25 -07001422 * 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 -07001423 * @node: node whose fallback list we're appending
1424 * @used_node_mask: nodemask_t of already used nodes
1425 *
1426 * We use a number of factors to determine which is the next node that should
1427 * appear on a given node's fallback list. The node should not have appeared
1428 * already in @node's fallback list, and it should be the next closest node
1429 * according to the distance array (which contains arbitrary distance values
1430 * from each node to each node in the system), and should also prefer nodes
1431 * with no CPUs, since presumably they'll have very little allocation pressure
1432 * on them otherwise.
1433 * It returns -1 if no node is found.
1434 */
1435static int __init find_next_best_node(int node, nodemask_t *used_node_mask)
1436{
1437 int i, n, val;
1438 int min_val = INT_MAX;
1439 int best_node = -1;
1440
1441 for_each_online_node(i) {
1442 cpumask_t tmp;
1443
1444 /* Start from local node */
1445 n = (node+i) % num_online_nodes();
1446
1447 /* Don't want a node to appear more than once */
1448 if (node_isset(n, *used_node_mask))
1449 continue;
1450
1451 /* Use the local node if we haven't already */
1452 if (!node_isset(node, *used_node_mask)) {
1453 best_node = node;
1454 break;
1455 }
1456
1457 /* Use the distance array to find the distance */
1458 val = node_distance(node, n);
1459
1460 /* Give preference to headless and unused nodes */
1461 tmp = node_to_cpumask(n);
1462 if (!cpus_empty(tmp))
1463 val += PENALTY_FOR_NODE_WITH_CPUS;
1464
1465 /* Slight preference for less loaded node */
1466 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
1467 val += node_load[n];
1468
1469 if (val < min_val) {
1470 min_val = val;
1471 best_node = n;
1472 }
1473 }
1474
1475 if (best_node >= 0)
1476 node_set(best_node, *used_node_mask);
1477
1478 return best_node;
1479}
1480
1481static void __init build_zonelists(pg_data_t *pgdat)
1482{
1483 int i, j, k, node, local_node;
1484 int prev_node, load;
1485 struct zonelist *zonelist;
1486 nodemask_t used_mask;
1487
1488 /* initialize zonelists */
1489 for (i = 0; i < GFP_ZONETYPES; i++) {
1490 zonelist = pgdat->node_zonelists + i;
1491 zonelist->zones[0] = NULL;
1492 }
1493
1494 /* NUMA-aware ordering of nodes */
1495 local_node = pgdat->node_id;
1496 load = num_online_nodes();
1497 prev_node = local_node;
1498 nodes_clear(used_mask);
1499 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
1500 /*
1501 * We don't want to pressure a particular node.
1502 * So adding penalty to the first node in same
1503 * distance group to make it round-robin.
1504 */
1505 if (node_distance(local_node, node) !=
1506 node_distance(local_node, prev_node))
1507 node_load[node] += load;
1508 prev_node = node;
1509 load--;
1510 for (i = 0; i < GFP_ZONETYPES; i++) {
1511 zonelist = pgdat->node_zonelists + i;
1512 for (j = 0; zonelist->zones[j] != NULL; j++);
1513
1514 k = ZONE_NORMAL;
1515 if (i & __GFP_HIGHMEM)
1516 k = ZONE_HIGHMEM;
1517 if (i & __GFP_DMA)
1518 k = ZONE_DMA;
1519
1520 j = build_zonelists_node(NODE_DATA(node), zonelist, j, k);
1521 zonelist->zones[j] = NULL;
1522 }
1523 }
1524}
1525
1526#else /* CONFIG_NUMA */
1527
1528static void __init build_zonelists(pg_data_t *pgdat)
1529{
1530 int i, j, k, node, local_node;
1531
1532 local_node = pgdat->node_id;
1533 for (i = 0; i < GFP_ZONETYPES; i++) {
1534 struct zonelist *zonelist;
1535
1536 zonelist = pgdat->node_zonelists + i;
1537
1538 j = 0;
1539 k = ZONE_NORMAL;
1540 if (i & __GFP_HIGHMEM)
1541 k = ZONE_HIGHMEM;
1542 if (i & __GFP_DMA)
1543 k = ZONE_DMA;
1544
1545 j = build_zonelists_node(pgdat, zonelist, j, k);
1546 /*
1547 * Now we build the zonelist so that it contains the zones
1548 * of all the other nodes.
1549 * We don't want to pressure a particular node, so when
1550 * building the zones for node N, we make sure that the
1551 * zones coming right after the local ones are those from
1552 * node N+1 (modulo N)
1553 */
1554 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
1555 if (!node_online(node))
1556 continue;
1557 j = build_zonelists_node(NODE_DATA(node), zonelist, j, k);
1558 }
1559 for (node = 0; node < local_node; node++) {
1560 if (!node_online(node))
1561 continue;
1562 j = build_zonelists_node(NODE_DATA(node), zonelist, j, k);
1563 }
1564
1565 zonelist->zones[j] = NULL;
1566 }
1567}
1568
1569#endif /* CONFIG_NUMA */
1570
1571void __init build_all_zonelists(void)
1572{
1573 int i;
1574
1575 for_each_online_node(i)
1576 build_zonelists(NODE_DATA(i));
1577 printk("Built %i zonelists\n", num_online_nodes());
1578 cpuset_init_current_mems_allowed();
1579}
1580
1581/*
1582 * Helper functions to size the waitqueue hash table.
1583 * Essentially these want to choose hash table sizes sufficiently
1584 * large so that collisions trying to wait on pages are rare.
1585 * But in fact, the number of active page waitqueues on typical
1586 * systems is ridiculously low, less than 200. So this is even
1587 * conservative, even though it seems large.
1588 *
1589 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
1590 * waitqueues, i.e. the size of the waitq table given the number of pages.
1591 */
1592#define PAGES_PER_WAITQUEUE 256
1593
1594static inline unsigned long wait_table_size(unsigned long pages)
1595{
1596 unsigned long size = 1;
1597
1598 pages /= PAGES_PER_WAITQUEUE;
1599
1600 while (size < pages)
1601 size <<= 1;
1602
1603 /*
1604 * Once we have dozens or even hundreds of threads sleeping
1605 * on IO we've got bigger problems than wait queue collision.
1606 * Limit the size of the wait table to a reasonable size.
1607 */
1608 size = min(size, 4096UL);
1609
1610 return max(size, 4UL);
1611}
1612
1613/*
1614 * This is an integer logarithm so that shifts can be used later
1615 * to extract the more random high bits from the multiplicative
1616 * hash function before the remainder is taken.
1617 */
1618static inline unsigned long wait_table_bits(unsigned long size)
1619{
1620 return ffz(~size);
1621}
1622
1623#define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
1624
1625static void __init calculate_zone_totalpages(struct pglist_data *pgdat,
1626 unsigned long *zones_size, unsigned long *zholes_size)
1627{
1628 unsigned long realtotalpages, totalpages = 0;
1629 int i;
1630
1631 for (i = 0; i < MAX_NR_ZONES; i++)
1632 totalpages += zones_size[i];
1633 pgdat->node_spanned_pages = totalpages;
1634
1635 realtotalpages = totalpages;
1636 if (zholes_size)
1637 for (i = 0; i < MAX_NR_ZONES; i++)
1638 realtotalpages -= zholes_size[i];
1639 pgdat->node_present_pages = realtotalpages;
1640 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, realtotalpages);
1641}
1642
1643
1644/*
1645 * Initially all pages are reserved - free ones are freed
1646 * up by free_all_bootmem() once the early boot process is
1647 * done. Non-atomic initialization, single-pass.
1648 */
1649void __init memmap_init_zone(unsigned long size, int nid, unsigned long zone,
1650 unsigned long start_pfn)
1651{
1652 struct page *start = pfn_to_page(start_pfn);
1653 struct page *page;
1654
1655 for (page = start; page < (start + size); page++) {
1656 set_page_zone(page, NODEZONE(nid, zone));
1657 set_page_count(page, 0);
1658 reset_page_mapcount(page);
1659 SetPageReserved(page);
1660 INIT_LIST_HEAD(&page->lru);
1661#ifdef WANT_PAGE_VIRTUAL
1662 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1663 if (!is_highmem_idx(zone))
1664 set_page_address(page, __va(start_pfn << PAGE_SHIFT));
1665#endif
1666 start_pfn++;
1667 }
1668}
1669
1670void zone_init_free_lists(struct pglist_data *pgdat, struct zone *zone,
1671 unsigned long size)
1672{
1673 int order;
1674 for (order = 0; order < MAX_ORDER ; order++) {
1675 INIT_LIST_HEAD(&zone->free_area[order].free_list);
1676 zone->free_area[order].nr_free = 0;
1677 }
1678}
1679
1680#ifndef __HAVE_ARCH_MEMMAP_INIT
1681#define memmap_init(size, nid, zone, start_pfn) \
1682 memmap_init_zone((size), (nid), (zone), (start_pfn))
1683#endif
1684
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001685static int __devinit zone_batchsize(struct zone *zone)
1686{
1687 int batch;
1688
1689 /*
1690 * The per-cpu-pages pools are set to around 1000th of the
1691 * size of the zone. But no more than 1/4 of a meg - there's
1692 * no point in going beyond the size of L2 cache.
1693 *
1694 * OK, so we don't know how big the cache is. So guess.
1695 */
1696 batch = zone->present_pages / 1024;
1697 if (batch * PAGE_SIZE > 256 * 1024)
1698 batch = (256 * 1024) / PAGE_SIZE;
1699 batch /= 4; /* We effectively *= 4 below */
1700 if (batch < 1)
1701 batch = 1;
1702
1703 /*
1704 * Clamp the batch to a 2^n - 1 value. Having a power
1705 * of 2 value was found to be more likely to have
1706 * suboptimal cache aliasing properties in some cases.
1707 *
1708 * For example if 2 tasks are alternately allocating
1709 * batches of pages, one task can end up with a lot
1710 * of pages of one half of the possible page colors
1711 * and the other with pages of the other colors.
1712 */
1713 batch = (1 << fls(batch + batch/2)) - 1;
1714 return batch;
1715}
1716
1717#ifdef CONFIG_NUMA
1718/*
1719 * Dynamicaly allocate memory for the
1720 * per cpu pageset array in struct zone.
1721 */
1722static int __devinit process_zones(int cpu)
1723{
1724 struct zone *zone, *dzone;
1725 int i;
1726
1727 for_each_zone(zone) {
1728 struct per_cpu_pageset *npageset = NULL;
1729
1730 npageset = kmalloc_node(sizeof(struct per_cpu_pageset),
1731 GFP_KERNEL, cpu_to_node(cpu));
1732 if (!npageset) {
1733 zone->pageset[cpu] = NULL;
1734 goto bad;
1735 }
1736
1737 if (zone->pageset[cpu]) {
1738 memcpy(npageset, zone->pageset[cpu],
1739 sizeof(struct per_cpu_pageset));
1740
1741 /* Relocate lists */
1742 for (i = 0; i < 2; i++) {
1743 INIT_LIST_HEAD(&npageset->pcp[i].list);
1744 list_splice(&zone->pageset[cpu]->pcp[i].list,
1745 &npageset->pcp[i].list);
1746 }
1747 } else {
1748 struct per_cpu_pages *pcp;
1749 unsigned long batch;
1750
1751 batch = zone_batchsize(zone);
1752
1753 pcp = &npageset->pcp[0]; /* hot */
1754 pcp->count = 0;
1755 pcp->low = 2 * batch;
1756 pcp->high = 6 * batch;
1757 pcp->batch = 1 * batch;
1758 INIT_LIST_HEAD(&pcp->list);
1759
1760 pcp = &npageset->pcp[1]; /* cold*/
1761 pcp->count = 0;
1762 pcp->low = 0;
1763 pcp->high = 2 * batch;
1764 pcp->batch = 1 * batch;
1765 INIT_LIST_HEAD(&pcp->list);
1766 }
1767 zone->pageset[cpu] = npageset;
1768 }
1769
1770 return 0;
1771bad:
1772 for_each_zone(dzone) {
1773 if (dzone == zone)
1774 break;
1775 kfree(dzone->pageset[cpu]);
1776 dzone->pageset[cpu] = NULL;
1777 }
1778 return -ENOMEM;
1779}
1780
1781static inline void free_zone_pagesets(int cpu)
1782{
1783#ifdef CONFIG_NUMA
1784 struct zone *zone;
1785
1786 for_each_zone(zone) {
1787 struct per_cpu_pageset *pset = zone_pcp(zone, cpu);
1788
1789 zone_pcp(zone, cpu) = NULL;
1790 kfree(pset);
1791 }
1792#endif
1793}
1794
1795static int __devinit pageset_cpuup_callback(struct notifier_block *nfb,
1796 unsigned long action,
1797 void *hcpu)
1798{
1799 int cpu = (long)hcpu;
1800 int ret = NOTIFY_OK;
1801
1802 switch (action) {
1803 case CPU_UP_PREPARE:
1804 if (process_zones(cpu))
1805 ret = NOTIFY_BAD;
1806 break;
1807#ifdef CONFIG_HOTPLUG_CPU
1808 case CPU_DEAD:
1809 free_zone_pagesets(cpu);
1810 break;
1811#endif
1812 default:
1813 break;
1814 }
1815 return ret;
1816}
1817
1818static struct notifier_block pageset_notifier =
1819 { &pageset_cpuup_callback, NULL, 0 };
1820
1821void __init setup_per_cpu_pageset()
1822{
1823 int err;
1824
1825 /* Initialize per_cpu_pageset for cpu 0.
1826 * A cpuup callback will do this for every cpu
1827 * as it comes online
1828 */
1829 err = process_zones(smp_processor_id());
1830 BUG_ON(err);
1831 register_cpu_notifier(&pageset_notifier);
1832}
1833
1834#endif
1835
Linus Torvalds1da177e2005-04-16 15:20:36 -07001836/*
1837 * Set up the zone data structures:
1838 * - mark all pages reserved
1839 * - mark all memory queues empty
1840 * - clear the memory bitmaps
1841 */
1842static void __init free_area_init_core(struct pglist_data *pgdat,
1843 unsigned long *zones_size, unsigned long *zholes_size)
1844{
1845 unsigned long i, j;
1846 const unsigned long zone_required_alignment = 1UL << (MAX_ORDER-1);
1847 int cpu, nid = pgdat->node_id;
1848 unsigned long zone_start_pfn = pgdat->node_start_pfn;
1849
1850 pgdat->nr_zones = 0;
1851 init_waitqueue_head(&pgdat->kswapd_wait);
1852 pgdat->kswapd_max_order = 0;
1853
1854 for (j = 0; j < MAX_NR_ZONES; j++) {
1855 struct zone *zone = pgdat->node_zones + j;
1856 unsigned long size, realsize;
1857 unsigned long batch;
1858
1859 zone_table[NODEZONE(nid, j)] = zone;
1860 realsize = size = zones_size[j];
1861 if (zholes_size)
1862 realsize -= zholes_size[j];
1863
1864 if (j == ZONE_DMA || j == ZONE_NORMAL)
1865 nr_kernel_pages += realsize;
1866 nr_all_pages += realsize;
1867
1868 zone->spanned_pages = size;
1869 zone->present_pages = realsize;
1870 zone->name = zone_names[j];
1871 spin_lock_init(&zone->lock);
1872 spin_lock_init(&zone->lru_lock);
1873 zone->zone_pgdat = pgdat;
1874 zone->free_pages = 0;
1875
1876 zone->temp_priority = zone->prev_priority = DEF_PRIORITY;
1877
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001878 batch = zone_batchsize(zone);
Nick Piggin8e30f272005-05-01 08:58:36 -07001879
Linus Torvalds1da177e2005-04-16 15:20:36 -07001880 for (cpu = 0; cpu < NR_CPUS; cpu++) {
1881 struct per_cpu_pages *pcp;
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001882#ifdef CONFIG_NUMA
1883 struct per_cpu_pageset *pgset;
1884 pgset = &pageset_table[nid*MAX_NR_ZONES*NR_CPUS +
1885 (j * NR_CPUS) + cpu];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001886
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001887 zone->pageset[cpu] = pgset;
1888#else
1889 struct per_cpu_pageset *pgset = zone_pcp(zone, cpu);
1890#endif
1891
1892 pcp = &pgset->pcp[0]; /* hot */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001893 pcp->count = 0;
1894 pcp->low = 2 * batch;
1895 pcp->high = 6 * batch;
1896 pcp->batch = 1 * batch;
1897 INIT_LIST_HEAD(&pcp->list);
1898
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001899 pcp = &pgset->pcp[1]; /* cold */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001900 pcp->count = 0;
1901 pcp->low = 0;
1902 pcp->high = 2 * batch;
1903 pcp->batch = 1 * batch;
1904 INIT_LIST_HEAD(&pcp->list);
1905 }
1906 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n",
1907 zone_names[j], realsize, batch);
1908 INIT_LIST_HEAD(&zone->active_list);
1909 INIT_LIST_HEAD(&zone->inactive_list);
1910 zone->nr_scan_active = 0;
1911 zone->nr_scan_inactive = 0;
1912 zone->nr_active = 0;
1913 zone->nr_inactive = 0;
Martin Hicks1e7e5a92005-06-21 17:14:43 -07001914 atomic_set(&zone->reclaim_in_progress, -1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001915 if (!size)
1916 continue;
1917
1918 /*
1919 * The per-page waitqueue mechanism uses hashed waitqueues
1920 * per zone.
1921 */
1922 zone->wait_table_size = wait_table_size(size);
1923 zone->wait_table_bits =
1924 wait_table_bits(zone->wait_table_size);
1925 zone->wait_table = (wait_queue_head_t *)
1926 alloc_bootmem_node(pgdat, zone->wait_table_size
1927 * sizeof(wait_queue_head_t));
1928
1929 for(i = 0; i < zone->wait_table_size; ++i)
1930 init_waitqueue_head(zone->wait_table + i);
1931
1932 pgdat->nr_zones = j+1;
1933
1934 zone->zone_mem_map = pfn_to_page(zone_start_pfn);
1935 zone->zone_start_pfn = zone_start_pfn;
1936
1937 if ((zone_start_pfn) & (zone_required_alignment-1))
1938 printk(KERN_CRIT "BUG: wrong zone alignment, it will crash\n");
1939
1940 memmap_init(size, nid, j, zone_start_pfn);
1941
1942 zone_start_pfn += size;
1943
1944 zone_init_free_lists(pgdat, zone, zone->spanned_pages);
1945 }
1946}
1947
1948static void __init alloc_node_mem_map(struct pglist_data *pgdat)
1949{
1950 unsigned long size;
1951
1952 /* Skip empty nodes */
1953 if (!pgdat->node_spanned_pages)
1954 return;
1955
1956 /* ia64 gets its own node_mem_map, before this, without bootmem */
1957 if (!pgdat->node_mem_map) {
1958 size = (pgdat->node_spanned_pages + 1) * sizeof(struct page);
1959 pgdat->node_mem_map = alloc_bootmem_node(pgdat, size);
1960 }
1961#ifndef CONFIG_DISCONTIGMEM
1962 /*
1963 * With no DISCONTIG, the global mem_map is just set as node 0's
1964 */
1965 if (pgdat == NODE_DATA(0))
1966 mem_map = NODE_DATA(0)->node_mem_map;
1967#endif
1968}
1969
1970void __init free_area_init_node(int nid, struct pglist_data *pgdat,
1971 unsigned long *zones_size, unsigned long node_start_pfn,
1972 unsigned long *zholes_size)
1973{
1974 pgdat->node_id = nid;
1975 pgdat->node_start_pfn = node_start_pfn;
1976 calculate_zone_totalpages(pgdat, zones_size, zholes_size);
1977
1978 alloc_node_mem_map(pgdat);
1979
1980 free_area_init_core(pgdat, zones_size, zholes_size);
1981}
1982
1983#ifndef CONFIG_DISCONTIGMEM
1984static bootmem_data_t contig_bootmem_data;
1985struct pglist_data contig_page_data = { .bdata = &contig_bootmem_data };
1986
1987EXPORT_SYMBOL(contig_page_data);
1988
1989void __init free_area_init(unsigned long *zones_size)
1990{
1991 free_area_init_node(0, &contig_page_data, zones_size,
1992 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
1993}
1994#endif
1995
1996#ifdef CONFIG_PROC_FS
1997
1998#include <linux/seq_file.h>
1999
2000static void *frag_start(struct seq_file *m, loff_t *pos)
2001{
2002 pg_data_t *pgdat;
2003 loff_t node = *pos;
2004
2005 for (pgdat = pgdat_list; pgdat && node; pgdat = pgdat->pgdat_next)
2006 --node;
2007
2008 return pgdat;
2009}
2010
2011static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
2012{
2013 pg_data_t *pgdat = (pg_data_t *)arg;
2014
2015 (*pos)++;
2016 return pgdat->pgdat_next;
2017}
2018
2019static void frag_stop(struct seq_file *m, void *arg)
2020{
2021}
2022
2023/*
2024 * This walks the free areas for each zone.
2025 */
2026static int frag_show(struct seq_file *m, void *arg)
2027{
2028 pg_data_t *pgdat = (pg_data_t *)arg;
2029 struct zone *zone;
2030 struct zone *node_zones = pgdat->node_zones;
2031 unsigned long flags;
2032 int order;
2033
2034 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
2035 if (!zone->present_pages)
2036 continue;
2037
2038 spin_lock_irqsave(&zone->lock, flags);
2039 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
2040 for (order = 0; order < MAX_ORDER; ++order)
2041 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
2042 spin_unlock_irqrestore(&zone->lock, flags);
2043 seq_putc(m, '\n');
2044 }
2045 return 0;
2046}
2047
2048struct seq_operations fragmentation_op = {
2049 .start = frag_start,
2050 .next = frag_next,
2051 .stop = frag_stop,
2052 .show = frag_show,
2053};
2054
Nikita Danilov295ab932005-06-21 17:14:38 -07002055/*
2056 * Output information about zones in @pgdat.
2057 */
2058static int zoneinfo_show(struct seq_file *m, void *arg)
2059{
2060 pg_data_t *pgdat = arg;
2061 struct zone *zone;
2062 struct zone *node_zones = pgdat->node_zones;
2063 unsigned long flags;
2064
2065 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; zone++) {
2066 int i;
2067
2068 if (!zone->present_pages)
2069 continue;
2070
2071 spin_lock_irqsave(&zone->lock, flags);
2072 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
2073 seq_printf(m,
2074 "\n pages free %lu"
2075 "\n min %lu"
2076 "\n low %lu"
2077 "\n high %lu"
2078 "\n active %lu"
2079 "\n inactive %lu"
2080 "\n scanned %lu (a: %lu i: %lu)"
2081 "\n spanned %lu"
2082 "\n present %lu",
2083 zone->free_pages,
2084 zone->pages_min,
2085 zone->pages_low,
2086 zone->pages_high,
2087 zone->nr_active,
2088 zone->nr_inactive,
2089 zone->pages_scanned,
2090 zone->nr_scan_active, zone->nr_scan_inactive,
2091 zone->spanned_pages,
2092 zone->present_pages);
2093 seq_printf(m,
2094 "\n protection: (%lu",
2095 zone->lowmem_reserve[0]);
2096 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
2097 seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
2098 seq_printf(m,
2099 ")"
2100 "\n pagesets");
2101 for (i = 0; i < ARRAY_SIZE(zone->pageset); i++) {
2102 struct per_cpu_pageset *pageset;
2103 int j;
2104
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07002105 pageset = zone_pcp(zone, i);
Nikita Danilov295ab932005-06-21 17:14:38 -07002106 for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {
2107 if (pageset->pcp[j].count)
2108 break;
2109 }
2110 if (j == ARRAY_SIZE(pageset->pcp))
2111 continue;
2112 for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {
2113 seq_printf(m,
2114 "\n cpu: %i pcp: %i"
2115 "\n count: %i"
2116 "\n low: %i"
2117 "\n high: %i"
2118 "\n batch: %i",
2119 i, j,
2120 pageset->pcp[j].count,
2121 pageset->pcp[j].low,
2122 pageset->pcp[j].high,
2123 pageset->pcp[j].batch);
2124 }
2125#ifdef CONFIG_NUMA
2126 seq_printf(m,
2127 "\n numa_hit: %lu"
2128 "\n numa_miss: %lu"
2129 "\n numa_foreign: %lu"
2130 "\n interleave_hit: %lu"
2131 "\n local_node: %lu"
2132 "\n other_node: %lu",
2133 pageset->numa_hit,
2134 pageset->numa_miss,
2135 pageset->numa_foreign,
2136 pageset->interleave_hit,
2137 pageset->local_node,
2138 pageset->other_node);
2139#endif
2140 }
2141 seq_printf(m,
2142 "\n all_unreclaimable: %u"
2143 "\n prev_priority: %i"
2144 "\n temp_priority: %i"
2145 "\n start_pfn: %lu",
2146 zone->all_unreclaimable,
2147 zone->prev_priority,
2148 zone->temp_priority,
2149 zone->zone_start_pfn);
2150 spin_unlock_irqrestore(&zone->lock, flags);
2151 seq_putc(m, '\n');
2152 }
2153 return 0;
2154}
2155
2156struct seq_operations zoneinfo_op = {
2157 .start = frag_start, /* iterate over all zones. The same as in
2158 * fragmentation. */
2159 .next = frag_next,
2160 .stop = frag_stop,
2161 .show = zoneinfo_show,
2162};
2163
Linus Torvalds1da177e2005-04-16 15:20:36 -07002164static char *vmstat_text[] = {
2165 "nr_dirty",
2166 "nr_writeback",
2167 "nr_unstable",
2168 "nr_page_table_pages",
2169 "nr_mapped",
2170 "nr_slab",
2171
2172 "pgpgin",
2173 "pgpgout",
2174 "pswpin",
2175 "pswpout",
2176 "pgalloc_high",
2177
2178 "pgalloc_normal",
2179 "pgalloc_dma",
2180 "pgfree",
2181 "pgactivate",
2182 "pgdeactivate",
2183
2184 "pgfault",
2185 "pgmajfault",
2186 "pgrefill_high",
2187 "pgrefill_normal",
2188 "pgrefill_dma",
2189
2190 "pgsteal_high",
2191 "pgsteal_normal",
2192 "pgsteal_dma",
2193 "pgscan_kswapd_high",
2194 "pgscan_kswapd_normal",
2195
2196 "pgscan_kswapd_dma",
2197 "pgscan_direct_high",
2198 "pgscan_direct_normal",
2199 "pgscan_direct_dma",
2200 "pginodesteal",
2201
2202 "slabs_scanned",
2203 "kswapd_steal",
2204 "kswapd_inodesteal",
2205 "pageoutrun",
2206 "allocstall",
2207
2208 "pgrotated",
KAMEZAWA Hiroyukiedfbe2b2005-05-01 08:58:37 -07002209 "nr_bounce",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002210};
2211
2212static void *vmstat_start(struct seq_file *m, loff_t *pos)
2213{
2214 struct page_state *ps;
2215
2216 if (*pos >= ARRAY_SIZE(vmstat_text))
2217 return NULL;
2218
2219 ps = kmalloc(sizeof(*ps), GFP_KERNEL);
2220 m->private = ps;
2221 if (!ps)
2222 return ERR_PTR(-ENOMEM);
2223 get_full_page_state(ps);
2224 ps->pgpgin /= 2; /* sectors -> kbytes */
2225 ps->pgpgout /= 2;
2226 return (unsigned long *)ps + *pos;
2227}
2228
2229static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
2230{
2231 (*pos)++;
2232 if (*pos >= ARRAY_SIZE(vmstat_text))
2233 return NULL;
2234 return (unsigned long *)m->private + *pos;
2235}
2236
2237static int vmstat_show(struct seq_file *m, void *arg)
2238{
2239 unsigned long *l = arg;
2240 unsigned long off = l - (unsigned long *)m->private;
2241
2242 seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
2243 return 0;
2244}
2245
2246static void vmstat_stop(struct seq_file *m, void *arg)
2247{
2248 kfree(m->private);
2249 m->private = NULL;
2250}
2251
2252struct seq_operations vmstat_op = {
2253 .start = vmstat_start,
2254 .next = vmstat_next,
2255 .stop = vmstat_stop,
2256 .show = vmstat_show,
2257};
2258
2259#endif /* CONFIG_PROC_FS */
2260
2261#ifdef CONFIG_HOTPLUG_CPU
2262static int page_alloc_cpu_notify(struct notifier_block *self,
2263 unsigned long action, void *hcpu)
2264{
2265 int cpu = (unsigned long)hcpu;
2266 long *count;
2267 unsigned long *src, *dest;
2268
2269 if (action == CPU_DEAD) {
2270 int i;
2271
2272 /* Drain local pagecache count. */
2273 count = &per_cpu(nr_pagecache_local, cpu);
2274 atomic_add(*count, &nr_pagecache);
2275 *count = 0;
2276 local_irq_disable();
2277 __drain_pages(cpu);
2278
2279 /* Add dead cpu's page_states to our own. */
2280 dest = (unsigned long *)&__get_cpu_var(page_states);
2281 src = (unsigned long *)&per_cpu(page_states, cpu);
2282
2283 for (i = 0; i < sizeof(struct page_state)/sizeof(unsigned long);
2284 i++) {
2285 dest[i] += src[i];
2286 src[i] = 0;
2287 }
2288
2289 local_irq_enable();
2290 }
2291 return NOTIFY_OK;
2292}
2293#endif /* CONFIG_HOTPLUG_CPU */
2294
2295void __init page_alloc_init(void)
2296{
2297 hotcpu_notifier(page_alloc_cpu_notify, 0);
2298}
2299
2300/*
2301 * setup_per_zone_lowmem_reserve - called whenever
2302 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
2303 * has a correct pages reserved value, so an adequate number of
2304 * pages are left in the zone after a successful __alloc_pages().
2305 */
2306static void setup_per_zone_lowmem_reserve(void)
2307{
2308 struct pglist_data *pgdat;
2309 int j, idx;
2310
2311 for_each_pgdat(pgdat) {
2312 for (j = 0; j < MAX_NR_ZONES; j++) {
2313 struct zone *zone = pgdat->node_zones + j;
2314 unsigned long present_pages = zone->present_pages;
2315
2316 zone->lowmem_reserve[j] = 0;
2317
2318 for (idx = j-1; idx >= 0; idx--) {
2319 struct zone *lower_zone;
2320
2321 if (sysctl_lowmem_reserve_ratio[idx] < 1)
2322 sysctl_lowmem_reserve_ratio[idx] = 1;
2323
2324 lower_zone = pgdat->node_zones + idx;
2325 lower_zone->lowmem_reserve[j] = present_pages /
2326 sysctl_lowmem_reserve_ratio[idx];
2327 present_pages += lower_zone->present_pages;
2328 }
2329 }
2330 }
2331}
2332
2333/*
2334 * setup_per_zone_pages_min - called when min_free_kbytes changes. Ensures
2335 * that the pages_{min,low,high} values for each zone are set correctly
2336 * with respect to min_free_kbytes.
2337 */
2338static void setup_per_zone_pages_min(void)
2339{
2340 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
2341 unsigned long lowmem_pages = 0;
2342 struct zone *zone;
2343 unsigned long flags;
2344
2345 /* Calculate total number of !ZONE_HIGHMEM pages */
2346 for_each_zone(zone) {
2347 if (!is_highmem(zone))
2348 lowmem_pages += zone->present_pages;
2349 }
2350
2351 for_each_zone(zone) {
2352 spin_lock_irqsave(&zone->lru_lock, flags);
2353 if (is_highmem(zone)) {
2354 /*
2355 * Often, highmem doesn't need to reserve any pages.
2356 * But the pages_min/low/high values are also used for
2357 * batching up page reclaim activity so we need a
2358 * decent value here.
2359 */
2360 int min_pages;
2361
2362 min_pages = zone->present_pages / 1024;
2363 if (min_pages < SWAP_CLUSTER_MAX)
2364 min_pages = SWAP_CLUSTER_MAX;
2365 if (min_pages > 128)
2366 min_pages = 128;
2367 zone->pages_min = min_pages;
2368 } else {
Nikita Danilov295ab932005-06-21 17:14:38 -07002369 /* if it's a lowmem zone, reserve a number of pages
Linus Torvalds1da177e2005-04-16 15:20:36 -07002370 * proportionate to the zone's size.
2371 */
Nikita Danilov295ab932005-06-21 17:14:38 -07002372 zone->pages_min = (pages_min * zone->present_pages) /
Linus Torvalds1da177e2005-04-16 15:20:36 -07002373 lowmem_pages;
2374 }
2375
2376 /*
2377 * When interpreting these watermarks, just keep in mind that:
2378 * zone->pages_min == (zone->pages_min * 4) / 4;
2379 */
2380 zone->pages_low = (zone->pages_min * 5) / 4;
2381 zone->pages_high = (zone->pages_min * 6) / 4;
2382 spin_unlock_irqrestore(&zone->lru_lock, flags);
2383 }
2384}
2385
2386/*
2387 * Initialise min_free_kbytes.
2388 *
2389 * For small machines we want it small (128k min). For large machines
2390 * we want it large (64MB max). But it is not linear, because network
2391 * bandwidth does not increase linearly with machine size. We use
2392 *
2393 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
2394 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
2395 *
2396 * which yields
2397 *
2398 * 16MB: 512k
2399 * 32MB: 724k
2400 * 64MB: 1024k
2401 * 128MB: 1448k
2402 * 256MB: 2048k
2403 * 512MB: 2896k
2404 * 1024MB: 4096k
2405 * 2048MB: 5792k
2406 * 4096MB: 8192k
2407 * 8192MB: 11584k
2408 * 16384MB: 16384k
2409 */
2410static int __init init_per_zone_pages_min(void)
2411{
2412 unsigned long lowmem_kbytes;
2413
2414 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
2415
2416 min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
2417 if (min_free_kbytes < 128)
2418 min_free_kbytes = 128;
2419 if (min_free_kbytes > 65536)
2420 min_free_kbytes = 65536;
2421 setup_per_zone_pages_min();
2422 setup_per_zone_lowmem_reserve();
2423 return 0;
2424}
2425module_init(init_per_zone_pages_min)
2426
2427/*
2428 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
2429 * that we can call two helper functions whenever min_free_kbytes
2430 * changes.
2431 */
2432int min_free_kbytes_sysctl_handler(ctl_table *table, int write,
2433 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
2434{
2435 proc_dointvec(table, write, file, buffer, length, ppos);
2436 setup_per_zone_pages_min();
2437 return 0;
2438}
2439
2440/*
2441 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
2442 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
2443 * whenever sysctl_lowmem_reserve_ratio changes.
2444 *
2445 * The reserve ratio obviously has absolutely no relation with the
2446 * pages_min watermarks. The lowmem reserve ratio can only make sense
2447 * if in function of the boot time zone sizes.
2448 */
2449int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
2450 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
2451{
2452 proc_dointvec_minmax(table, write, file, buffer, length, ppos);
2453 setup_per_zone_lowmem_reserve();
2454 return 0;
2455}
2456
2457__initdata int hashdist = HASHDIST_DEFAULT;
2458
2459#ifdef CONFIG_NUMA
2460static int __init set_hashdist(char *str)
2461{
2462 if (!str)
2463 return 0;
2464 hashdist = simple_strtoul(str, &str, 0);
2465 return 1;
2466}
2467__setup("hashdist=", set_hashdist);
2468#endif
2469
2470/*
2471 * allocate a large system hash table from bootmem
2472 * - it is assumed that the hash table must contain an exact power-of-2
2473 * quantity of entries
2474 * - limit is the number of hash buckets, not the total allocation size
2475 */
2476void *__init alloc_large_system_hash(const char *tablename,
2477 unsigned long bucketsize,
2478 unsigned long numentries,
2479 int scale,
2480 int flags,
2481 unsigned int *_hash_shift,
2482 unsigned int *_hash_mask,
2483 unsigned long limit)
2484{
2485 unsigned long long max = limit;
2486 unsigned long log2qty, size;
2487 void *table = NULL;
2488
2489 /* allow the kernel cmdline to have a say */
2490 if (!numentries) {
2491 /* round applicable memory size up to nearest megabyte */
2492 numentries = (flags & HASH_HIGHMEM) ? nr_all_pages : nr_kernel_pages;
2493 numentries += (1UL << (20 - PAGE_SHIFT)) - 1;
2494 numentries >>= 20 - PAGE_SHIFT;
2495 numentries <<= 20 - PAGE_SHIFT;
2496
2497 /* limit to 1 bucket per 2^scale bytes of low memory */
2498 if (scale > PAGE_SHIFT)
2499 numentries >>= (scale - PAGE_SHIFT);
2500 else
2501 numentries <<= (PAGE_SHIFT - scale);
2502 }
2503 /* rounded up to nearest power of 2 in size */
2504 numentries = 1UL << (long_log2(numentries) + 1);
2505
2506 /* limit allocation size to 1/16 total memory by default */
2507 if (max == 0) {
2508 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
2509 do_div(max, bucketsize);
2510 }
2511
2512 if (numentries > max)
2513 numentries = max;
2514
2515 log2qty = long_log2(numentries);
2516
2517 do {
2518 size = bucketsize << log2qty;
2519 if (flags & HASH_EARLY)
2520 table = alloc_bootmem(size);
2521 else if (hashdist)
2522 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
2523 else {
2524 unsigned long order;
2525 for (order = 0; ((1UL << order) << PAGE_SHIFT) < size; order++)
2526 ;
2527 table = (void*) __get_free_pages(GFP_ATOMIC, order);
2528 }
2529 } while (!table && size > PAGE_SIZE && --log2qty);
2530
2531 if (!table)
2532 panic("Failed to allocate %s hash table\n", tablename);
2533
2534 printk("%s hash table entries: %d (order: %d, %lu bytes)\n",
2535 tablename,
2536 (1U << log2qty),
2537 long_log2(size) - PAGE_SHIFT,
2538 size);
2539
2540 if (_hash_shift)
2541 *_hash_shift = log2qty;
2542 if (_hash_mask)
2543 *_hash_mask = (1 << log2qty) - 1;
2544
2545 return table;
2546}