blob: 183abf39b445dcbc73579ea873b5900d062c872c [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>
39
40#include <asm/tlbflush.h>
41#include "internal.h"
42
43/*
44 * MCD - HACK: Find somewhere to initialize this EARLY, or make this
45 * initializer cleaner
46 */
Christoph Lameterc3d8c142005-09-06 15:16:33 -070047nodemask_t node_online_map __read_mostly = { { [0] = 1UL } };
Dean Nelson7223a932005-03-23 19:00:00 -070048EXPORT_SYMBOL(node_online_map);
Christoph Lameterc3d8c142005-09-06 15:16:33 -070049nodemask_t node_possible_map __read_mostly = NODE_MASK_ALL;
Dean Nelson7223a932005-03-23 19:00:00 -070050EXPORT_SYMBOL(node_possible_map);
Christoph Lameterc3d8c142005-09-06 15:16:33 -070051struct pglist_data *pgdat_list __read_mostly;
Ravikiran G Thirumalai6c231b72005-09-06 15:17:45 -070052unsigned long totalram_pages __read_mostly;
53unsigned long totalhigh_pages __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070054long nr_swap_pages;
55
56/*
57 * results with 256, 32 in the lowmem_reserve sysctl:
58 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
59 * 1G machine -> (16M dma, 784M normal, 224M high)
60 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
61 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
62 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
63 */
64int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { 256, 32 };
65
66EXPORT_SYMBOL(totalram_pages);
67EXPORT_SYMBOL(nr_swap_pages);
68
69/*
70 * Used by page_zone() to look up the address of the struct zone whose
71 * id is encoded in the upper bits of page->flags
72 */
Christoph Lameterc3d8c142005-09-06 15:16:33 -070073struct zone *zone_table[1 << ZONETABLE_SHIFT] __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070074EXPORT_SYMBOL(zone_table);
75
76static char *zone_names[MAX_NR_ZONES] = { "DMA", "Normal", "HighMem" };
77int min_free_kbytes = 1024;
78
79unsigned long __initdata nr_kernel_pages;
80unsigned long __initdata nr_all_pages;
81
Dave Hansenc6a57e12005-10-29 18:16:52 -070082static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
Linus Torvalds1da177e2005-04-16 15:20:36 -070083{
Dave Hansenbdc8cb92005-10-29 18:16:53 -070084 int ret = 0;
85 unsigned seq;
86 unsigned long pfn = page_to_pfn(page);
Dave Hansenc6a57e12005-10-29 18:16:52 -070087
Dave Hansenbdc8cb92005-10-29 18:16:53 -070088 do {
89 seq = zone_span_seqbegin(zone);
90 if (pfn >= zone->zone_start_pfn + zone->spanned_pages)
91 ret = 1;
92 else if (pfn < zone->zone_start_pfn)
93 ret = 1;
94 } while (zone_span_seqretry(zone, seq));
95
96 return ret;
Dave Hansenc6a57e12005-10-29 18:16:52 -070097}
98
99static int page_is_consistent(struct zone *zone, struct page *page)
100{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101#ifdef CONFIG_HOLES_IN_ZONE
102 if (!pfn_valid(page_to_pfn(page)))
Dave Hansenc6a57e12005-10-29 18:16:52 -0700103 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104#endif
105 if (zone != page_zone(page))
Dave Hansenc6a57e12005-10-29 18:16:52 -0700106 return 0;
107
108 return 1;
109}
110/*
111 * Temporary debugging check for pages not lying within a given zone.
112 */
113static int bad_range(struct zone *zone, struct page *page)
114{
115 if (page_outside_zone_boundaries(zone, page))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 return 1;
Dave Hansenc6a57e12005-10-29 18:16:52 -0700117 if (!page_is_consistent(zone, page))
118 return 1;
119
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 return 0;
121}
122
123static void bad_page(const char *function, struct page *page)
124{
125 printk(KERN_EMERG "Bad page state at %s (in process '%s', page %p)\n",
126 function, current->comm, page);
127 printk(KERN_EMERG "flags:0x%0*lx mapping:%p mapcount:%d count:%d\n",
128 (int)(2*sizeof(page_flags_t)), (unsigned long)page->flags,
129 page->mapping, page_mapcount(page), page_count(page));
130 printk(KERN_EMERG "Backtrace:\n");
131 dump_stack();
132 printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n");
Hugh Dickins334795e2005-06-21 17:15:08 -0700133 page->flags &= ~(1 << PG_lru |
134 1 << PG_private |
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 1 << PG_locked |
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 1 << PG_active |
137 1 << PG_dirty |
Hugh Dickins334795e2005-06-21 17:15:08 -0700138 1 << PG_reclaim |
139 1 << PG_slab |
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 1 << PG_swapcache |
Nick Pigginb5810032005-10-29 18:16:12 -0700141 1 << PG_writeback |
142 1 << PG_reserved );
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 set_page_count(page, 0);
144 reset_page_mapcount(page);
145 page->mapping = NULL;
Randy Dunlap9f158332005-09-13 01:25:16 -0700146 add_taint(TAINT_BAD_PAGE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147}
148
149#ifndef CONFIG_HUGETLB_PAGE
150#define prep_compound_page(page, order) do { } while (0)
151#define destroy_compound_page(page, order) do { } while (0)
152#else
153/*
154 * Higher-order pages are called "compound pages". They are structured thusly:
155 *
156 * The first PAGE_SIZE page is called the "head page".
157 *
158 * The remaining PAGE_SIZE pages are called "tail pages".
159 *
160 * All pages have PG_compound set. All pages have their ->private pointing at
161 * the head page (even the head page has this).
162 *
163 * The first tail page's ->mapping, if non-zero, holds the address of the
164 * compound page's put_page() function.
165 *
166 * The order of the allocation is stored in the first tail page's ->index
167 * This is only for debug at present. This usage means that zero-order pages
168 * may not be compound.
169 */
170static void prep_compound_page(struct page *page, unsigned long order)
171{
172 int i;
173 int nr_pages = 1 << order;
174
175 page[1].mapping = NULL;
176 page[1].index = order;
177 for (i = 0; i < nr_pages; i++) {
178 struct page *p = page + i;
179
180 SetPageCompound(p);
Hugh Dickins4c21e2f2005-10-29 18:16:40 -0700181 set_page_private(p, (unsigned long)page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 }
183}
184
185static void destroy_compound_page(struct page *page, unsigned long order)
186{
187 int i;
188 int nr_pages = 1 << order;
189
190 if (!PageCompound(page))
191 return;
192
193 if (page[1].index != order)
194 bad_page(__FUNCTION__, page);
195
196 for (i = 0; i < nr_pages; i++) {
197 struct page *p = page + i;
198
199 if (!PageCompound(p))
200 bad_page(__FUNCTION__, page);
Hugh Dickins4c21e2f2005-10-29 18:16:40 -0700201 if (page_private(p) != (unsigned long)page)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 bad_page(__FUNCTION__, page);
203 ClearPageCompound(p);
204 }
205}
206#endif /* CONFIG_HUGETLB_PAGE */
207
208/*
209 * function for dealing with page's order in buddy system.
210 * zone->lock is already acquired when we use these.
211 * So, we don't need atomic page->flags operations here.
212 */
213static inline unsigned long page_order(struct page *page) {
Hugh Dickins4c21e2f2005-10-29 18:16:40 -0700214 return page_private(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215}
216
217static inline void set_page_order(struct page *page, int order) {
Hugh Dickins4c21e2f2005-10-29 18:16:40 -0700218 set_page_private(page, order);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 __SetPagePrivate(page);
220}
221
222static inline void rmv_page_order(struct page *page)
223{
224 __ClearPagePrivate(page);
Hugh Dickins4c21e2f2005-10-29 18:16:40 -0700225 set_page_private(page, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226}
227
228/*
229 * Locate the struct page for both the matching buddy in our
230 * pair (buddy1) and the combined O(n+1) page they form (page).
231 *
232 * 1) Any buddy B1 will have an order O twin B2 which satisfies
233 * the following equation:
234 * B2 = B1 ^ (1 << O)
235 * For example, if the starting buddy (buddy2) is #8 its order
236 * 1 buddy is #10:
237 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
238 *
239 * 2) Any buddy B will have an order O+1 parent P which
240 * satisfies the following equation:
241 * P = B & ~(1 << O)
242 *
243 * Assumption: *_mem_map is contigious at least up to MAX_ORDER
244 */
245static inline struct page *
246__page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order)
247{
248 unsigned long buddy_idx = page_idx ^ (1 << order);
249
250 return page + (buddy_idx - page_idx);
251}
252
253static inline unsigned long
254__find_combined_index(unsigned long page_idx, unsigned int order)
255{
256 return (page_idx & ~(1 << order));
257}
258
259/*
260 * This function checks whether a page is free && is the buddy
261 * we can do coalesce a page and its buddy if
262 * (a) the buddy is free &&
263 * (b) the buddy is on the buddy system &&
264 * (c) a page and its buddy have the same order.
Hugh Dickins4c21e2f2005-10-29 18:16:40 -0700265 * for recording page's order, we use page_private(page) and PG_private.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 *
267 */
268static inline int page_is_buddy(struct page *page, int order)
269{
270 if (PagePrivate(page) &&
271 (page_order(page) == order) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 page_count(page) == 0)
273 return 1;
274 return 0;
275}
276
277/*
278 * Freeing function for a buddy system allocator.
279 *
280 * The concept of a buddy system is to maintain direct-mapped table
281 * (containing bit values) for memory blocks of various "orders".
282 * The bottom level table contains the map for the smallest allocatable
283 * units of memory (here, pages), and each level above it describes
284 * pairs of units from the levels below, hence, "buddies".
285 * At a high level, all that happens here is marking the table entry
286 * at the bottom level available, and propagating the changes upward
287 * as necessary, plus some accounting needed to play nicely with other
288 * parts of the VM system.
289 * At each level, we keep a list of pages, which are heads of continuous
290 * free pages of length of (1 << order) and marked with PG_Private.Page's
Hugh Dickins4c21e2f2005-10-29 18:16:40 -0700291 * order is recorded in page_private(page) field.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 * So when we are allocating or freeing one, we can derive the state of the
293 * other. That is, if we allocate a small block, and both were
294 * free, the remainder of the region must be split into blocks.
295 * If a block is freed, and its buddy is also free, then this
296 * triggers coalescing into a block of larger size.
297 *
298 * -- wli
299 */
300
301static inline void __free_pages_bulk (struct page *page,
302 struct zone *zone, unsigned int order)
303{
304 unsigned long page_idx;
305 int order_size = 1 << order;
306
307 if (unlikely(order))
308 destroy_compound_page(page, order);
309
310 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
311
312 BUG_ON(page_idx & (order_size - 1));
313 BUG_ON(bad_range(zone, page));
314
315 zone->free_pages += order_size;
316 while (order < MAX_ORDER-1) {
317 unsigned long combined_idx;
318 struct free_area *area;
319 struct page *buddy;
320
321 combined_idx = __find_combined_index(page_idx, order);
322 buddy = __page_find_buddy(page, page_idx, order);
323
324 if (bad_range(zone, buddy))
325 break;
326 if (!page_is_buddy(buddy, order))
327 break; /* Move the buddy up one level. */
328 list_del(&buddy->lru);
329 area = zone->free_area + order;
330 area->nr_free--;
331 rmv_page_order(buddy);
332 page = page + (combined_idx - page_idx);
333 page_idx = combined_idx;
334 order++;
335 }
336 set_page_order(page, order);
337 list_add(&page->lru, &zone->free_area[order].free_list);
338 zone->free_area[order].nr_free++;
339}
340
341static inline void free_pages_check(const char *function, struct page *page)
342{
343 if ( page_mapcount(page) ||
344 page->mapping != NULL ||
345 page_count(page) != 0 ||
346 (page->flags & (
347 1 << PG_lru |
348 1 << PG_private |
349 1 << PG_locked |
350 1 << PG_active |
351 1 << PG_reclaim |
352 1 << PG_slab |
353 1 << PG_swapcache |
Nick Pigginb5810032005-10-29 18:16:12 -0700354 1 << PG_writeback |
355 1 << PG_reserved )))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 bad_page(function, page);
357 if (PageDirty(page))
Nick Piggin242e5462005-09-03 15:54:50 -0700358 __ClearPageDirty(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359}
360
361/*
362 * Frees a list of pages.
363 * Assumes all pages on list are in same zone, and of same order.
Renaud Lienhart207f36e2005-09-10 00:26:59 -0700364 * count is the number of pages to free.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365 *
366 * If the zone was previously in an "all pages pinned" state then look to
367 * see if this freeing clears that state.
368 *
369 * And clear the zone's pages_scanned counter, to hold off the "all pages are
370 * pinned" detection logic.
371 */
372static int
373free_pages_bulk(struct zone *zone, int count,
374 struct list_head *list, unsigned int order)
375{
376 unsigned long flags;
377 struct page *page = NULL;
378 int ret = 0;
379
380 spin_lock_irqsave(&zone->lock, flags);
381 zone->all_unreclaimable = 0;
382 zone->pages_scanned = 0;
383 while (!list_empty(list) && count--) {
384 page = list_entry(list->prev, struct page, lru);
385 /* have to delete it as __free_pages_bulk list manipulates */
386 list_del(&page->lru);
387 __free_pages_bulk(page, zone, order);
388 ret++;
389 }
390 spin_unlock_irqrestore(&zone->lock, flags);
391 return ret;
392}
393
394void __free_pages_ok(struct page *page, unsigned int order)
395{
396 LIST_HEAD(list);
397 int i;
398
399 arch_free_page(page, order);
400
401 mod_page_state(pgfree, 1 << order);
402
403#ifndef CONFIG_MMU
404 if (order > 0)
405 for (i = 1 ; i < (1 << order) ; ++i)
406 __put_page(page + i);
407#endif
408
409 for (i = 0 ; i < (1 << order) ; ++i)
410 free_pages_check(__FUNCTION__, page + i);
411 list_add(&page->lru, &list);
412 kernel_map_pages(page, 1<<order, 0);
413 free_pages_bulk(page_zone(page), 1, &list, order);
414}
415
416
417/*
418 * The order of subdivision here is critical for the IO subsystem.
419 * Please do not alter this order without good reasons and regression
420 * testing. Specifically, as large blocks of memory are subdivided,
421 * the order in which smaller blocks are delivered depends on the order
422 * they're subdivided in this function. This is the primary factor
423 * influencing the order in which pages are delivered to the IO
424 * subsystem according to empirical testing, and this is also justified
425 * by considering the behavior of a buddy system containing a single
426 * large block of memory acted on by a series of small allocations.
427 * This behavior is a critical factor in sglist merging's success.
428 *
429 * -- wli
430 */
431static inline struct page *
432expand(struct zone *zone, struct page *page,
433 int low, int high, struct free_area *area)
434{
435 unsigned long size = 1 << high;
436
437 while (high > low) {
438 area--;
439 high--;
440 size >>= 1;
441 BUG_ON(bad_range(zone, &page[size]));
442 list_add(&page[size].lru, &area->free_list);
443 area->nr_free++;
444 set_page_order(&page[size], high);
445 }
446 return page;
447}
448
449void set_page_refs(struct page *page, int order)
450{
451#ifdef CONFIG_MMU
452 set_page_count(page, 1);
453#else
454 int i;
455
456 /*
457 * We need to reference all the pages for this order, otherwise if
458 * anyone accesses one of the pages with (get/put) it will be freed.
459 * - eg: access_process_vm()
460 */
461 for (i = 0; i < (1 << order); i++)
462 set_page_count(page + i, 1);
463#endif /* CONFIG_MMU */
464}
465
466/*
467 * This page is about to be returned from the page allocator
468 */
469static void prep_new_page(struct page *page, int order)
470{
Hugh Dickins334795e2005-06-21 17:15:08 -0700471 if ( page_mapcount(page) ||
472 page->mapping != NULL ||
473 page_count(page) != 0 ||
474 (page->flags & (
475 1 << PG_lru |
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 1 << PG_private |
477 1 << PG_locked |
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478 1 << PG_active |
479 1 << PG_dirty |
480 1 << PG_reclaim |
Hugh Dickins334795e2005-06-21 17:15:08 -0700481 1 << PG_slab |
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482 1 << PG_swapcache |
Nick Pigginb5810032005-10-29 18:16:12 -0700483 1 << PG_writeback |
484 1 << PG_reserved )))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 bad_page(__FUNCTION__, page);
486
487 page->flags &= ~(1 << PG_uptodate | 1 << PG_error |
488 1 << PG_referenced | 1 << PG_arch_1 |
489 1 << PG_checked | 1 << PG_mappedtodisk);
Hugh Dickins4c21e2f2005-10-29 18:16:40 -0700490 set_page_private(page, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 set_page_refs(page, order);
492 kernel_map_pages(page, 1 << order, 1);
493}
494
495/*
496 * Do the hard work of removing an element from the buddy allocator.
497 * Call me with the zone->lock already held.
498 */
499static struct page *__rmqueue(struct zone *zone, unsigned int order)
500{
501 struct free_area * area;
502 unsigned int current_order;
503 struct page *page;
504
505 for (current_order = order; current_order < MAX_ORDER; ++current_order) {
506 area = zone->free_area + current_order;
507 if (list_empty(&area->free_list))
508 continue;
509
510 page = list_entry(area->free_list.next, struct page, lru);
511 list_del(&page->lru);
512 rmv_page_order(page);
513 area->nr_free--;
514 zone->free_pages -= 1UL << order;
515 return expand(zone, page, order, current_order, area);
516 }
517
518 return NULL;
519}
520
521/*
522 * Obtain a specified number of elements from the buddy allocator, all under
523 * a single hold of the lock, for efficiency. Add them to the supplied list.
524 * Returns the number of new pages which were placed at *list.
525 */
526static int rmqueue_bulk(struct zone *zone, unsigned int order,
527 unsigned long count, struct list_head *list)
528{
529 unsigned long flags;
530 int i;
531 int allocated = 0;
532 struct page *page;
533
534 spin_lock_irqsave(&zone->lock, flags);
535 for (i = 0; i < count; ++i) {
536 page = __rmqueue(zone, order);
537 if (page == NULL)
538 break;
539 allocated++;
540 list_add_tail(&page->lru, list);
541 }
542 spin_unlock_irqrestore(&zone->lock, flags);
543 return allocated;
544}
545
Christoph Lameter4ae7c032005-06-21 17:14:57 -0700546#ifdef CONFIG_NUMA
547/* Called from the slab reaper to drain remote pagesets */
548void drain_remote_pages(void)
549{
550 struct zone *zone;
551 int i;
552 unsigned long flags;
553
554 local_irq_save(flags);
555 for_each_zone(zone) {
556 struct per_cpu_pageset *pset;
557
558 /* Do not drain local pagesets */
559 if (zone->zone_pgdat->node_id == numa_node_id())
560 continue;
561
562 pset = zone->pageset[smp_processor_id()];
563 for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) {
564 struct per_cpu_pages *pcp;
565
566 pcp = &pset->pcp[i];
567 if (pcp->count)
568 pcp->count -= free_pages_bulk(zone, pcp->count,
569 &pcp->list, 0);
570 }
571 }
572 local_irq_restore(flags);
573}
574#endif
575
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576#if defined(CONFIG_PM) || defined(CONFIG_HOTPLUG_CPU)
577static void __drain_pages(unsigned int cpu)
578{
579 struct zone *zone;
580 int i;
581
582 for_each_zone(zone) {
583 struct per_cpu_pageset *pset;
584
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700585 pset = zone_pcp(zone, cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586 for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) {
587 struct per_cpu_pages *pcp;
588
589 pcp = &pset->pcp[i];
590 pcp->count -= free_pages_bulk(zone, pcp->count,
591 &pcp->list, 0);
592 }
593 }
594}
595#endif /* CONFIG_PM || CONFIG_HOTPLUG_CPU */
596
597#ifdef CONFIG_PM
598
599void mark_free_pages(struct zone *zone)
600{
601 unsigned long zone_pfn, flags;
602 int order;
603 struct list_head *curr;
604
605 if (!zone->spanned_pages)
606 return;
607
608 spin_lock_irqsave(&zone->lock, flags);
609 for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
610 ClearPageNosaveFree(pfn_to_page(zone_pfn + zone->zone_start_pfn));
611
612 for (order = MAX_ORDER - 1; order >= 0; --order)
613 list_for_each(curr, &zone->free_area[order].free_list) {
614 unsigned long start_pfn, i;
615
616 start_pfn = page_to_pfn(list_entry(curr, struct page, lru));
617
618 for (i=0; i < (1<<order); i++)
619 SetPageNosaveFree(pfn_to_page(start_pfn+i));
620 }
621 spin_unlock_irqrestore(&zone->lock, flags);
622}
623
624/*
625 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
626 */
627void drain_local_pages(void)
628{
629 unsigned long flags;
630
631 local_irq_save(flags);
632 __drain_pages(smp_processor_id());
633 local_irq_restore(flags);
634}
635#endif /* CONFIG_PM */
636
637static void zone_statistics(struct zonelist *zonelist, struct zone *z)
638{
639#ifdef CONFIG_NUMA
640 unsigned long flags;
641 int cpu;
642 pg_data_t *pg = z->zone_pgdat;
643 pg_data_t *orig = zonelist->zones[0]->zone_pgdat;
644 struct per_cpu_pageset *p;
645
646 local_irq_save(flags);
647 cpu = smp_processor_id();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700648 p = zone_pcp(z,cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649 if (pg == orig) {
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700650 p->numa_hit++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651 } else {
652 p->numa_miss++;
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700653 zone_pcp(zonelist->zones[0], cpu)->numa_foreign++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654 }
655 if (pg == NODE_DATA(numa_node_id()))
656 p->local_node++;
657 else
658 p->other_node++;
659 local_irq_restore(flags);
660#endif
661}
662
663/*
664 * Free a 0-order page
665 */
666static void FASTCALL(free_hot_cold_page(struct page *page, int cold));
667static void fastcall free_hot_cold_page(struct page *page, int cold)
668{
669 struct zone *zone = page_zone(page);
670 struct per_cpu_pages *pcp;
671 unsigned long flags;
672
673 arch_free_page(page, 0);
674
675 kernel_map_pages(page, 1, 0);
676 inc_page_state(pgfree);
677 if (PageAnon(page))
678 page->mapping = NULL;
679 free_pages_check(__FUNCTION__, page);
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700680 pcp = &zone_pcp(zone, get_cpu())->pcp[cold];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 local_irq_save(flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682 list_add(&page->lru, &pcp->list);
683 pcp->count++;
Christoph Lameter2caaad42005-06-21 17:15:00 -0700684 if (pcp->count >= pcp->high)
685 pcp->count -= free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686 local_irq_restore(flags);
687 put_cpu();
688}
689
690void fastcall free_hot_page(struct page *page)
691{
692 free_hot_cold_page(page, 0);
693}
694
695void fastcall free_cold_page(struct page *page)
696{
697 free_hot_cold_page(page, 1);
698}
699
Al Virodd0fc662005-10-07 07:46:04 +0100700static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701{
702 int i;
703
704 BUG_ON((gfp_flags & (__GFP_WAIT | __GFP_HIGHMEM)) == __GFP_HIGHMEM);
705 for(i = 0; i < (1 << order); i++)
706 clear_highpage(page + i);
707}
708
709/*
710 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
711 * we cheat by calling it from here, in the order > 0 path. Saves a branch
712 * or two.
713 */
714static struct page *
Al Virodd0fc662005-10-07 07:46:04 +0100715buffered_rmqueue(struct zone *zone, int order, gfp_t gfp_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716{
717 unsigned long flags;
718 struct page *page = NULL;
719 int cold = !!(gfp_flags & __GFP_COLD);
720
721 if (order == 0) {
722 struct per_cpu_pages *pcp;
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);
726 if (pcp->count <= pcp->low)
727 pcp->count += rmqueue_bulk(zone, 0,
728 pcp->batch, &pcp->list);
729 if (pcp->count) {
730 page = list_entry(pcp->list.next, struct page, lru);
731 list_del(&page->lru);
732 pcp->count--;
733 }
734 local_irq_restore(flags);
735 put_cpu();
736 }
737
738 if (page == NULL) {
739 spin_lock_irqsave(&zone->lock, flags);
740 page = __rmqueue(zone, order);
741 spin_unlock_irqrestore(&zone->lock, flags);
742 }
743
744 if (page != NULL) {
745 BUG_ON(bad_range(zone, page));
746 mod_page_state_zone(zone, pgalloc, 1 << order);
747 prep_new_page(page, order);
748
749 if (gfp_flags & __GFP_ZERO)
750 prep_zero_page(page, order, gfp_flags);
751
752 if (order && (gfp_flags & __GFP_COMP))
753 prep_compound_page(page, order);
754 }
755 return page;
756}
757
758/*
759 * Return 1 if free pages are above 'mark'. This takes into account the order
760 * of the allocation.
761 */
762int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
Al Viro260b2362005-10-21 03:22:44 -0400763 int classzone_idx, int can_try_harder, gfp_t gfp_high)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764{
765 /* free_pages my go negative - that's OK */
766 long min = mark, free_pages = z->free_pages - (1 << order) + 1;
767 int o;
768
769 if (gfp_high)
770 min -= min / 2;
771 if (can_try_harder)
772 min -= min / 4;
773
774 if (free_pages <= min + z->lowmem_reserve[classzone_idx])
775 return 0;
776 for (o = 0; o < order; o++) {
777 /* At the next order, this order's pages become unavailable */
778 free_pages -= z->free_area[o].nr_free << o;
779
780 /* Require fewer higher order pages to be free */
781 min >>= 1;
782
783 if (free_pages <= min)
784 return 0;
785 }
786 return 1;
787}
788
Martin Hicks753ee722005-06-21 17:14:41 -0700789static inline int
Al Virodd0fc662005-10-07 07:46:04 +0100790should_reclaim_zone(struct zone *z, gfp_t gfp_mask)
Martin Hicks753ee722005-06-21 17:14:41 -0700791{
792 if (!z->reclaim_pages)
793 return 0;
Martin Hicks0c35bba2005-06-21 17:14:42 -0700794 if (gfp_mask & __GFP_NORECLAIM)
795 return 0;
Martin Hicks753ee722005-06-21 17:14:41 -0700796 return 1;
797}
798
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799/*
800 * This is the 'heart' of the zoned buddy allocator.
801 */
802struct page * fastcall
Al Virodd0fc662005-10-07 07:46:04 +0100803__alloc_pages(gfp_t gfp_mask, unsigned int order,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804 struct zonelist *zonelist)
805{
Al Viro260b2362005-10-21 03:22:44 -0400806 const gfp_t wait = gfp_mask & __GFP_WAIT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807 struct zone **zones, *z;
808 struct page *page;
809 struct reclaim_state reclaim_state;
810 struct task_struct *p = current;
811 int i;
812 int classzone_idx;
813 int do_retry;
814 int can_try_harder;
815 int did_some_progress;
816
817 might_sleep_if(wait);
818
819 /*
820 * The caller may dip into page reserves a bit more if the caller
821 * cannot run direct reclaim, or is the caller has realtime scheduling
822 * policy
823 */
824 can_try_harder = (unlikely(rt_task(p)) && !in_interrupt()) || !wait;
825
826 zones = zonelist->zones; /* the list of zones suitable for gfp_mask */
827
828 if (unlikely(zones[0] == NULL)) {
829 /* Should this ever happen?? */
830 return NULL;
831 }
832
833 classzone_idx = zone_idx(zones[0]);
834
Martin Hicks753ee722005-06-21 17:14:41 -0700835restart:
Paul Jackson9bf22292005-09-06 15:18:12 -0700836 /*
837 * Go through the zonelist once, looking for a zone with enough free.
838 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
839 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700840 for (i = 0; (z = zones[i]) != NULL; i++) {
Martin Hicks753ee722005-06-21 17:14:41 -0700841 int do_reclaim = should_reclaim_zone(z, gfp_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842
Paul Jackson9bf22292005-09-06 15:18:12 -0700843 if (!cpuset_zone_allowed(z, __GFP_HARDWALL))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844 continue;
845
Martin Hicks753ee722005-06-21 17:14:41 -0700846 /*
847 * If the zone is to attempt early page reclaim then this loop
848 * will try to reclaim pages and check the watermark a second
849 * time before giving up and falling back to the next zone.
850 */
851zone_reclaim_retry:
852 if (!zone_watermark_ok(z, order, z->pages_low,
853 classzone_idx, 0, 0)) {
854 if (!do_reclaim)
855 continue;
856 else {
857 zone_reclaim(z, gfp_mask, order);
858 /* Only try reclaim once */
859 do_reclaim = 0;
860 goto zone_reclaim_retry;
861 }
862 }
863
Linus Torvalds1da177e2005-04-16 15:20:36 -0700864 page = buffered_rmqueue(z, order, gfp_mask);
865 if (page)
866 goto got_pg;
867 }
868
869 for (i = 0; (z = zones[i]) != NULL; i++)
870 wakeup_kswapd(z, order);
871
872 /*
873 * Go through the zonelist again. Let __GFP_HIGH and allocations
874 * coming from realtime tasks to go deeper into reserves
875 *
876 * This is the last chance, in general, before the goto nopage.
877 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
Paul Jackson9bf22292005-09-06 15:18:12 -0700878 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879 */
880 for (i = 0; (z = zones[i]) != NULL; i++) {
881 if (!zone_watermark_ok(z, order, z->pages_min,
882 classzone_idx, can_try_harder,
883 gfp_mask & __GFP_HIGH))
884 continue;
885
Paul Jackson9bf22292005-09-06 15:18:12 -0700886 if (wait && !cpuset_zone_allowed(z, gfp_mask))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887 continue;
888
889 page = buffered_rmqueue(z, order, gfp_mask);
890 if (page)
891 goto got_pg;
892 }
893
894 /* This allocation should allow future memory freeing. */
Nick Pigginb84a35b2005-05-01 08:58:36 -0700895
896 if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE)))
897 && !in_interrupt()) {
898 if (!(gfp_mask & __GFP_NOMEMALLOC)) {
899 /* go through the zonelist yet again, ignoring mins */
900 for (i = 0; (z = zones[i]) != NULL; i++) {
Paul Jackson9bf22292005-09-06 15:18:12 -0700901 if (!cpuset_zone_allowed(z, gfp_mask))
Nick Pigginb84a35b2005-05-01 08:58:36 -0700902 continue;
903 page = buffered_rmqueue(z, order, gfp_mask);
904 if (page)
905 goto got_pg;
906 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907 }
908 goto nopage;
909 }
910
911 /* Atomic allocations - we can't balance anything */
912 if (!wait)
913 goto nopage;
914
915rebalance:
916 cond_resched();
917
918 /* We now go into synchronous reclaim */
919 p->flags |= PF_MEMALLOC;
920 reclaim_state.reclaimed_slab = 0;
921 p->reclaim_state = &reclaim_state;
922
Darren Hart1ad539b2005-06-21 17:14:53 -0700923 did_some_progress = try_to_free_pages(zones, gfp_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924
925 p->reclaim_state = NULL;
926 p->flags &= ~PF_MEMALLOC;
927
928 cond_resched();
929
930 if (likely(did_some_progress)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931 for (i = 0; (z = zones[i]) != NULL; i++) {
932 if (!zone_watermark_ok(z, order, z->pages_min,
933 classzone_idx, can_try_harder,
934 gfp_mask & __GFP_HIGH))
935 continue;
936
Paul Jackson9bf22292005-09-06 15:18:12 -0700937 if (!cpuset_zone_allowed(z, gfp_mask))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938 continue;
939
940 page = buffered_rmqueue(z, order, gfp_mask);
941 if (page)
942 goto got_pg;
943 }
944 } else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
945 /*
946 * Go through the zonelist yet one more time, keep
947 * very high watermark here, this is only to catch
948 * a parallel oom killing, we must fail if we're still
949 * under heavy pressure.
950 */
951 for (i = 0; (z = zones[i]) != NULL; i++) {
952 if (!zone_watermark_ok(z, order, z->pages_high,
953 classzone_idx, 0, 0))
954 continue;
955
Paul Jackson9bf22292005-09-06 15:18:12 -0700956 if (!cpuset_zone_allowed(z, __GFP_HARDWALL))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700957 continue;
958
959 page = buffered_rmqueue(z, order, gfp_mask);
960 if (page)
961 goto got_pg;
962 }
963
Marcelo Tosatti79b9ce32005-07-07 17:56:04 -0700964 out_of_memory(gfp_mask, order);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965 goto restart;
966 }
967
968 /*
969 * Don't let big-order allocations loop unless the caller explicitly
970 * requests that. Wait for some write requests to complete then retry.
971 *
972 * In this implementation, __GFP_REPEAT means __GFP_NOFAIL for order
973 * <= 3, but that may not be true in other implementations.
974 */
975 do_retry = 0;
976 if (!(gfp_mask & __GFP_NORETRY)) {
977 if ((order <= 3) || (gfp_mask & __GFP_REPEAT))
978 do_retry = 1;
979 if (gfp_mask & __GFP_NOFAIL)
980 do_retry = 1;
981 }
982 if (do_retry) {
983 blk_congestion_wait(WRITE, HZ/50);
984 goto rebalance;
985 }
986
987nopage:
988 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) {
989 printk(KERN_WARNING "%s: page allocation failure."
990 " order:%d, mode:0x%x\n",
991 p->comm, order, gfp_mask);
992 dump_stack();
Janet Morgan578c2fd2005-06-21 17:14:56 -0700993 show_mem();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994 }
995 return NULL;
996got_pg:
997 zone_statistics(zonelist, z);
998 return page;
999}
1000
1001EXPORT_SYMBOL(__alloc_pages);
1002
1003/*
1004 * Common helper functions.
1005 */
Al Virodd0fc662005-10-07 07:46:04 +01001006fastcall unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001007{
1008 struct page * page;
1009 page = alloc_pages(gfp_mask, order);
1010 if (!page)
1011 return 0;
1012 return (unsigned long) page_address(page);
1013}
1014
1015EXPORT_SYMBOL(__get_free_pages);
1016
Al Virodd0fc662005-10-07 07:46:04 +01001017fastcall unsigned long get_zeroed_page(gfp_t gfp_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018{
1019 struct page * page;
1020
1021 /*
1022 * get_zeroed_page() returns a 32-bit address, which cannot represent
1023 * a highmem page
1024 */
Al Viro260b2362005-10-21 03:22:44 -04001025 BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001026
1027 page = alloc_pages(gfp_mask | __GFP_ZERO, 0);
1028 if (page)
1029 return (unsigned long) page_address(page);
1030 return 0;
1031}
1032
1033EXPORT_SYMBOL(get_zeroed_page);
1034
1035void __pagevec_free(struct pagevec *pvec)
1036{
1037 int i = pagevec_count(pvec);
1038
1039 while (--i >= 0)
1040 free_hot_cold_page(pvec->pages[i], pvec->cold);
1041}
1042
1043fastcall void __free_pages(struct page *page, unsigned int order)
1044{
Nick Pigginb5810032005-10-29 18:16:12 -07001045 if (put_page_testzero(page)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001046 if (order == 0)
1047 free_hot_page(page);
1048 else
1049 __free_pages_ok(page, order);
1050 }
1051}
1052
1053EXPORT_SYMBOL(__free_pages);
1054
1055fastcall void free_pages(unsigned long addr, unsigned int order)
1056{
1057 if (addr != 0) {
1058 BUG_ON(!virt_addr_valid((void *)addr));
1059 __free_pages(virt_to_page((void *)addr), order);
1060 }
1061}
1062
1063EXPORT_SYMBOL(free_pages);
1064
1065/*
1066 * Total amount of free (allocatable) RAM:
1067 */
1068unsigned int nr_free_pages(void)
1069{
1070 unsigned int sum = 0;
1071 struct zone *zone;
1072
1073 for_each_zone(zone)
1074 sum += zone->free_pages;
1075
1076 return sum;
1077}
1078
1079EXPORT_SYMBOL(nr_free_pages);
1080
1081#ifdef CONFIG_NUMA
1082unsigned int nr_free_pages_pgdat(pg_data_t *pgdat)
1083{
1084 unsigned int i, sum = 0;
1085
1086 for (i = 0; i < MAX_NR_ZONES; i++)
1087 sum += pgdat->node_zones[i].free_pages;
1088
1089 return sum;
1090}
1091#endif
1092
1093static unsigned int nr_free_zone_pages(int offset)
1094{
Martin J. Blighe310fd42005-07-29 22:59:18 -07001095 /* Just pick one node, since fallback list is circular */
1096 pg_data_t *pgdat = NODE_DATA(numa_node_id());
Linus Torvalds1da177e2005-04-16 15:20:36 -07001097 unsigned int sum = 0;
1098
Martin J. Blighe310fd42005-07-29 22:59:18 -07001099 struct zonelist *zonelist = pgdat->node_zonelists + offset;
1100 struct zone **zonep = zonelist->zones;
1101 struct zone *zone;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001102
Martin J. Blighe310fd42005-07-29 22:59:18 -07001103 for (zone = *zonep++; zone; zone = *zonep++) {
1104 unsigned long size = zone->present_pages;
1105 unsigned long high = zone->pages_high;
1106 if (size > high)
1107 sum += size - high;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001108 }
1109
1110 return sum;
1111}
1112
1113/*
1114 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
1115 */
1116unsigned int nr_free_buffer_pages(void)
1117{
Al Viroaf4ca452005-10-21 02:55:38 -04001118 return nr_free_zone_pages(gfp_zone(GFP_USER));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001119}
1120
1121/*
1122 * Amount of free RAM allocatable within all zones
1123 */
1124unsigned int nr_free_pagecache_pages(void)
1125{
Al Viroaf4ca452005-10-21 02:55:38 -04001126 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001127}
1128
1129#ifdef CONFIG_HIGHMEM
1130unsigned int nr_free_highpages (void)
1131{
1132 pg_data_t *pgdat;
1133 unsigned int pages = 0;
1134
1135 for_each_pgdat(pgdat)
1136 pages += pgdat->node_zones[ZONE_HIGHMEM].free_pages;
1137
1138 return pages;
1139}
1140#endif
1141
1142#ifdef CONFIG_NUMA
1143static void show_node(struct zone *zone)
1144{
1145 printk("Node %d ", zone->zone_pgdat->node_id);
1146}
1147#else
1148#define show_node(zone) do { } while (0)
1149#endif
1150
1151/*
1152 * Accumulate the page_state information across all CPUs.
1153 * The result is unavoidably approximate - it can change
1154 * during and after execution of this function.
1155 */
1156static DEFINE_PER_CPU(struct page_state, page_states) = {0};
1157
1158atomic_t nr_pagecache = ATOMIC_INIT(0);
1159EXPORT_SYMBOL(nr_pagecache);
1160#ifdef CONFIG_SMP
1161DEFINE_PER_CPU(long, nr_pagecache_local) = 0;
1162#endif
1163
Martin Hicksc07e02d2005-09-03 15:55:11 -07001164void __get_page_state(struct page_state *ret, int nr, cpumask_t *cpumask)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001165{
1166 int cpu = 0;
1167
1168 memset(ret, 0, sizeof(*ret));
Martin Hicksc07e02d2005-09-03 15:55:11 -07001169 cpus_and(*cpumask, *cpumask, cpu_online_map);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001170
Martin Hicksc07e02d2005-09-03 15:55:11 -07001171 cpu = first_cpu(*cpumask);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172 while (cpu < NR_CPUS) {
1173 unsigned long *in, *out, off;
1174
1175 in = (unsigned long *)&per_cpu(page_states, cpu);
1176
Martin Hicksc07e02d2005-09-03 15:55:11 -07001177 cpu = next_cpu(cpu, *cpumask);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001178
1179 if (cpu < NR_CPUS)
1180 prefetch(&per_cpu(page_states, cpu));
1181
1182 out = (unsigned long *)ret;
1183 for (off = 0; off < nr; off++)
1184 *out++ += *in++;
1185 }
1186}
1187
Martin Hicksc07e02d2005-09-03 15:55:11 -07001188void get_page_state_node(struct page_state *ret, int node)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001189{
1190 int nr;
Martin Hicksc07e02d2005-09-03 15:55:11 -07001191 cpumask_t mask = node_to_cpumask(node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001192
1193 nr = offsetof(struct page_state, GET_PAGE_STATE_LAST);
1194 nr /= sizeof(unsigned long);
1195
Martin Hicksc07e02d2005-09-03 15:55:11 -07001196 __get_page_state(ret, nr+1, &mask);
1197}
1198
1199void get_page_state(struct page_state *ret)
1200{
1201 int nr;
1202 cpumask_t mask = CPU_MASK_ALL;
1203
1204 nr = offsetof(struct page_state, GET_PAGE_STATE_LAST);
1205 nr /= sizeof(unsigned long);
1206
1207 __get_page_state(ret, nr + 1, &mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001208}
1209
1210void get_full_page_state(struct page_state *ret)
1211{
Martin Hicksc07e02d2005-09-03 15:55:11 -07001212 cpumask_t mask = CPU_MASK_ALL;
1213
1214 __get_page_state(ret, sizeof(*ret) / sizeof(unsigned long), &mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001215}
1216
Benjamin LaHaisec2f29ea2005-06-21 17:14:55 -07001217unsigned long __read_page_state(unsigned long offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001218{
1219 unsigned long ret = 0;
1220 int cpu;
1221
1222 for_each_online_cpu(cpu) {
1223 unsigned long in;
1224
1225 in = (unsigned long)&per_cpu(page_states, cpu) + offset;
1226 ret += *((unsigned long *)in);
1227 }
1228 return ret;
1229}
1230
Benjamin LaHaise83e5d8f2005-06-21 17:14:54 -07001231void __mod_page_state(unsigned long offset, unsigned long delta)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001232{
1233 unsigned long flags;
1234 void* ptr;
1235
1236 local_irq_save(flags);
1237 ptr = &__get_cpu_var(page_states);
1238 *(unsigned long*)(ptr + offset) += delta;
1239 local_irq_restore(flags);
1240}
1241
1242EXPORT_SYMBOL(__mod_page_state);
1243
1244void __get_zone_counts(unsigned long *active, unsigned long *inactive,
1245 unsigned long *free, struct pglist_data *pgdat)
1246{
1247 struct zone *zones = pgdat->node_zones;
1248 int i;
1249
1250 *active = 0;
1251 *inactive = 0;
1252 *free = 0;
1253 for (i = 0; i < MAX_NR_ZONES; i++) {
1254 *active += zones[i].nr_active;
1255 *inactive += zones[i].nr_inactive;
1256 *free += zones[i].free_pages;
1257 }
1258}
1259
1260void get_zone_counts(unsigned long *active,
1261 unsigned long *inactive, unsigned long *free)
1262{
1263 struct pglist_data *pgdat;
1264
1265 *active = 0;
1266 *inactive = 0;
1267 *free = 0;
1268 for_each_pgdat(pgdat) {
1269 unsigned long l, m, n;
1270 __get_zone_counts(&l, &m, &n, pgdat);
1271 *active += l;
1272 *inactive += m;
1273 *free += n;
1274 }
1275}
1276
1277void si_meminfo(struct sysinfo *val)
1278{
1279 val->totalram = totalram_pages;
1280 val->sharedram = 0;
1281 val->freeram = nr_free_pages();
1282 val->bufferram = nr_blockdev_pages();
1283#ifdef CONFIG_HIGHMEM
1284 val->totalhigh = totalhigh_pages;
1285 val->freehigh = nr_free_highpages();
1286#else
1287 val->totalhigh = 0;
1288 val->freehigh = 0;
1289#endif
1290 val->mem_unit = PAGE_SIZE;
1291}
1292
1293EXPORT_SYMBOL(si_meminfo);
1294
1295#ifdef CONFIG_NUMA
1296void si_meminfo_node(struct sysinfo *val, int nid)
1297{
1298 pg_data_t *pgdat = NODE_DATA(nid);
1299
1300 val->totalram = pgdat->node_present_pages;
1301 val->freeram = nr_free_pages_pgdat(pgdat);
1302 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
1303 val->freehigh = pgdat->node_zones[ZONE_HIGHMEM].free_pages;
1304 val->mem_unit = PAGE_SIZE;
1305}
1306#endif
1307
1308#define K(x) ((x) << (PAGE_SHIFT-10))
1309
1310/*
1311 * Show free area list (used inside shift_scroll-lock stuff)
1312 * We also calculate the percentage fragmentation. We do this by counting the
1313 * memory on each free list with the exception of the first item on the list.
1314 */
1315void show_free_areas(void)
1316{
1317 struct page_state ps;
1318 int cpu, temperature;
1319 unsigned long active;
1320 unsigned long inactive;
1321 unsigned long free;
1322 struct zone *zone;
1323
1324 for_each_zone(zone) {
1325 show_node(zone);
1326 printk("%s per-cpu:", zone->name);
1327
1328 if (!zone->present_pages) {
1329 printk(" empty\n");
1330 continue;
1331 } else
1332 printk("\n");
1333
1334 for (cpu = 0; cpu < NR_CPUS; ++cpu) {
1335 struct per_cpu_pageset *pageset;
1336
1337 if (!cpu_possible(cpu))
1338 continue;
1339
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001340 pageset = zone_pcp(zone, cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001341
1342 for (temperature = 0; temperature < 2; temperature++)
Christoph Lameter4ae7c032005-06-21 17:14:57 -07001343 printk("cpu %d %s: low %d, high %d, batch %d used:%d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001344 cpu,
1345 temperature ? "cold" : "hot",
1346 pageset->pcp[temperature].low,
1347 pageset->pcp[temperature].high,
Christoph Lameter4ae7c032005-06-21 17:14:57 -07001348 pageset->pcp[temperature].batch,
1349 pageset->pcp[temperature].count);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001350 }
1351 }
1352
1353 get_page_state(&ps);
1354 get_zone_counts(&active, &inactive, &free);
1355
Denis Vlasenkoc0d62212005-06-21 17:15:14 -07001356 printk("Free pages: %11ukB (%ukB HighMem)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001357 K(nr_free_pages()),
1358 K(nr_free_highpages()));
1359
1360 printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu "
1361 "unstable:%lu free:%u slab:%lu mapped:%lu pagetables:%lu\n",
1362 active,
1363 inactive,
1364 ps.nr_dirty,
1365 ps.nr_writeback,
1366 ps.nr_unstable,
1367 nr_free_pages(),
1368 ps.nr_slab,
1369 ps.nr_mapped,
1370 ps.nr_page_table_pages);
1371
1372 for_each_zone(zone) {
1373 int i;
1374
1375 show_node(zone);
1376 printk("%s"
1377 " free:%lukB"
1378 " min:%lukB"
1379 " low:%lukB"
1380 " high:%lukB"
1381 " active:%lukB"
1382 " inactive:%lukB"
1383 " present:%lukB"
1384 " pages_scanned:%lu"
1385 " all_unreclaimable? %s"
1386 "\n",
1387 zone->name,
1388 K(zone->free_pages),
1389 K(zone->pages_min),
1390 K(zone->pages_low),
1391 K(zone->pages_high),
1392 K(zone->nr_active),
1393 K(zone->nr_inactive),
1394 K(zone->present_pages),
1395 zone->pages_scanned,
1396 (zone->all_unreclaimable ? "yes" : "no")
1397 );
1398 printk("lowmem_reserve[]:");
1399 for (i = 0; i < MAX_NR_ZONES; i++)
1400 printk(" %lu", zone->lowmem_reserve[i]);
1401 printk("\n");
1402 }
1403
1404 for_each_zone(zone) {
1405 unsigned long nr, flags, order, total = 0;
1406
1407 show_node(zone);
1408 printk("%s: ", zone->name);
1409 if (!zone->present_pages) {
1410 printk("empty\n");
1411 continue;
1412 }
1413
1414 spin_lock_irqsave(&zone->lock, flags);
1415 for (order = 0; order < MAX_ORDER; order++) {
1416 nr = zone->free_area[order].nr_free;
1417 total += nr << order;
1418 printk("%lu*%lukB ", nr, K(1UL) << order);
1419 }
1420 spin_unlock_irqrestore(&zone->lock, flags);
1421 printk("= %lukB\n", K(total));
1422 }
1423
1424 show_swap_cache_info();
1425}
1426
1427/*
1428 * Builds allocation fallback zone lists.
1429 */
1430static int __init build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist, int j, int k)
1431{
1432 switch (k) {
1433 struct zone *zone;
1434 default:
1435 BUG();
1436 case ZONE_HIGHMEM:
1437 zone = pgdat->node_zones + ZONE_HIGHMEM;
1438 if (zone->present_pages) {
1439#ifndef CONFIG_HIGHMEM
1440 BUG();
1441#endif
1442 zonelist->zones[j++] = zone;
1443 }
1444 case ZONE_NORMAL:
1445 zone = pgdat->node_zones + ZONE_NORMAL;
1446 if (zone->present_pages)
1447 zonelist->zones[j++] = zone;
1448 case ZONE_DMA:
1449 zone = pgdat->node_zones + ZONE_DMA;
1450 if (zone->present_pages)
1451 zonelist->zones[j++] = zone;
1452 }
1453
1454 return j;
1455}
1456
Al Viro260b2362005-10-21 03:22:44 -04001457static inline int highest_zone(int zone_bits)
1458{
1459 int res = ZONE_NORMAL;
1460 if (zone_bits & (__force int)__GFP_HIGHMEM)
1461 res = ZONE_HIGHMEM;
1462 if (zone_bits & (__force int)__GFP_DMA)
1463 res = ZONE_DMA;
1464 return res;
1465}
1466
Linus Torvalds1da177e2005-04-16 15:20:36 -07001467#ifdef CONFIG_NUMA
1468#define MAX_NODE_LOAD (num_online_nodes())
1469static int __initdata node_load[MAX_NUMNODES];
1470/**
Pavel Pisa4dc3b162005-05-01 08:59:25 -07001471 * 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 -07001472 * @node: node whose fallback list we're appending
1473 * @used_node_mask: nodemask_t of already used nodes
1474 *
1475 * We use a number of factors to determine which is the next node that should
1476 * appear on a given node's fallback list. The node should not have appeared
1477 * already in @node's fallback list, and it should be the next closest node
1478 * according to the distance array (which contains arbitrary distance values
1479 * from each node to each node in the system), and should also prefer nodes
1480 * with no CPUs, since presumably they'll have very little allocation pressure
1481 * on them otherwise.
1482 * It returns -1 if no node is found.
1483 */
1484static int __init find_next_best_node(int node, nodemask_t *used_node_mask)
1485{
1486 int i, n, val;
1487 int min_val = INT_MAX;
1488 int best_node = -1;
1489
1490 for_each_online_node(i) {
1491 cpumask_t tmp;
1492
1493 /* Start from local node */
1494 n = (node+i) % num_online_nodes();
1495
1496 /* Don't want a node to appear more than once */
1497 if (node_isset(n, *used_node_mask))
1498 continue;
1499
1500 /* Use the local node if we haven't already */
1501 if (!node_isset(node, *used_node_mask)) {
1502 best_node = node;
1503 break;
1504 }
1505
1506 /* Use the distance array to find the distance */
1507 val = node_distance(node, n);
1508
1509 /* Give preference to headless and unused nodes */
1510 tmp = node_to_cpumask(n);
1511 if (!cpus_empty(tmp))
1512 val += PENALTY_FOR_NODE_WITH_CPUS;
1513
1514 /* Slight preference for less loaded node */
1515 val *= (MAX_NODE_LOAD*MAX_NUMNODES);
1516 val += node_load[n];
1517
1518 if (val < min_val) {
1519 min_val = val;
1520 best_node = n;
1521 }
1522 }
1523
1524 if (best_node >= 0)
1525 node_set(best_node, *used_node_mask);
1526
1527 return best_node;
1528}
1529
1530static void __init build_zonelists(pg_data_t *pgdat)
1531{
1532 int i, j, k, node, local_node;
1533 int prev_node, load;
1534 struct zonelist *zonelist;
1535 nodemask_t used_mask;
1536
1537 /* initialize zonelists */
1538 for (i = 0; i < GFP_ZONETYPES; i++) {
1539 zonelist = pgdat->node_zonelists + i;
1540 zonelist->zones[0] = NULL;
1541 }
1542
1543 /* NUMA-aware ordering of nodes */
1544 local_node = pgdat->node_id;
1545 load = num_online_nodes();
1546 prev_node = local_node;
1547 nodes_clear(used_mask);
1548 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
1549 /*
1550 * We don't want to pressure a particular node.
1551 * So adding penalty to the first node in same
1552 * distance group to make it round-robin.
1553 */
1554 if (node_distance(local_node, node) !=
1555 node_distance(local_node, prev_node))
1556 node_load[node] += load;
1557 prev_node = node;
1558 load--;
1559 for (i = 0; i < GFP_ZONETYPES; i++) {
1560 zonelist = pgdat->node_zonelists + i;
1561 for (j = 0; zonelist->zones[j] != NULL; j++);
1562
Al Viro260b2362005-10-21 03:22:44 -04001563 k = highest_zone(i);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001564
1565 j = build_zonelists_node(NODE_DATA(node), zonelist, j, k);
1566 zonelist->zones[j] = NULL;
1567 }
1568 }
1569}
1570
1571#else /* CONFIG_NUMA */
1572
1573static void __init build_zonelists(pg_data_t *pgdat)
1574{
1575 int i, j, k, node, local_node;
1576
1577 local_node = pgdat->node_id;
1578 for (i = 0; i < GFP_ZONETYPES; i++) {
1579 struct zonelist *zonelist;
1580
1581 zonelist = pgdat->node_zonelists + i;
1582
1583 j = 0;
Al Viro260b2362005-10-21 03:22:44 -04001584 k = highest_zone(i);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001585 j = build_zonelists_node(pgdat, zonelist, j, k);
1586 /*
1587 * Now we build the zonelist so that it contains the zones
1588 * of all the other nodes.
1589 * We don't want to pressure a particular node, so when
1590 * building the zones for node N, we make sure that the
1591 * zones coming right after the local ones are those from
1592 * node N+1 (modulo N)
1593 */
1594 for (node = local_node + 1; node < MAX_NUMNODES; node++) {
1595 if (!node_online(node))
1596 continue;
1597 j = build_zonelists_node(NODE_DATA(node), zonelist, j, k);
1598 }
1599 for (node = 0; node < local_node; node++) {
1600 if (!node_online(node))
1601 continue;
1602 j = build_zonelists_node(NODE_DATA(node), zonelist, j, k);
1603 }
1604
1605 zonelist->zones[j] = NULL;
1606 }
1607}
1608
1609#endif /* CONFIG_NUMA */
1610
1611void __init build_all_zonelists(void)
1612{
1613 int i;
1614
1615 for_each_online_node(i)
1616 build_zonelists(NODE_DATA(i));
1617 printk("Built %i zonelists\n", num_online_nodes());
1618 cpuset_init_current_mems_allowed();
1619}
1620
1621/*
1622 * Helper functions to size the waitqueue hash table.
1623 * Essentially these want to choose hash table sizes sufficiently
1624 * large so that collisions trying to wait on pages are rare.
1625 * But in fact, the number of active page waitqueues on typical
1626 * systems is ridiculously low, less than 200. So this is even
1627 * conservative, even though it seems large.
1628 *
1629 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
1630 * waitqueues, i.e. the size of the waitq table given the number of pages.
1631 */
1632#define PAGES_PER_WAITQUEUE 256
1633
1634static inline unsigned long wait_table_size(unsigned long pages)
1635{
1636 unsigned long size = 1;
1637
1638 pages /= PAGES_PER_WAITQUEUE;
1639
1640 while (size < pages)
1641 size <<= 1;
1642
1643 /*
1644 * Once we have dozens or even hundreds of threads sleeping
1645 * on IO we've got bigger problems than wait queue collision.
1646 * Limit the size of the wait table to a reasonable size.
1647 */
1648 size = min(size, 4096UL);
1649
1650 return max(size, 4UL);
1651}
1652
1653/*
1654 * This is an integer logarithm so that shifts can be used later
1655 * to extract the more random high bits from the multiplicative
1656 * hash function before the remainder is taken.
1657 */
1658static inline unsigned long wait_table_bits(unsigned long size)
1659{
1660 return ffz(~size);
1661}
1662
1663#define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
1664
1665static void __init calculate_zone_totalpages(struct pglist_data *pgdat,
1666 unsigned long *zones_size, unsigned long *zholes_size)
1667{
1668 unsigned long realtotalpages, totalpages = 0;
1669 int i;
1670
1671 for (i = 0; i < MAX_NR_ZONES; i++)
1672 totalpages += zones_size[i];
1673 pgdat->node_spanned_pages = totalpages;
1674
1675 realtotalpages = totalpages;
1676 if (zholes_size)
1677 for (i = 0; i < MAX_NR_ZONES; i++)
1678 realtotalpages -= zholes_size[i];
1679 pgdat->node_present_pages = realtotalpages;
1680 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, realtotalpages);
1681}
1682
1683
1684/*
1685 * Initially all pages are reserved - free ones are freed
1686 * up by free_all_bootmem() once the early boot process is
1687 * done. Non-atomic initialization, single-pass.
1688 */
Dave Hansen3947be12005-10-29 18:16:54 -07001689void __devinit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001690 unsigned long start_pfn)
1691{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001692 struct page *page;
Andy Whitcroft29751f62005-06-23 00:08:00 -07001693 unsigned long end_pfn = start_pfn + size;
1694 unsigned long pfn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001695
Andy Whitcroftd41dee32005-06-23 00:07:54 -07001696 for (pfn = start_pfn; pfn < end_pfn; pfn++, page++) {
1697 if (!early_pfn_valid(pfn))
1698 continue;
Andy Whitcroft641c7672005-06-23 00:07:59 -07001699 if (!early_pfn_in_nid(pfn, nid))
1700 continue;
Andy Whitcroftd41dee32005-06-23 00:07:54 -07001701 page = pfn_to_page(pfn);
1702 set_page_links(page, zone, nid, pfn);
Nick Pigginb5810032005-10-29 18:16:12 -07001703 set_page_count(page, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001704 reset_page_mapcount(page);
1705 SetPageReserved(page);
1706 INIT_LIST_HEAD(&page->lru);
1707#ifdef WANT_PAGE_VIRTUAL
1708 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1709 if (!is_highmem_idx(zone))
Bob Picco3212c6b2005-06-27 14:36:28 -07001710 set_page_address(page, __va(pfn << PAGE_SHIFT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001711#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001712 }
1713}
1714
1715void zone_init_free_lists(struct pglist_data *pgdat, struct zone *zone,
1716 unsigned long size)
1717{
1718 int order;
1719 for (order = 0; order < MAX_ORDER ; order++) {
1720 INIT_LIST_HEAD(&zone->free_area[order].free_list);
1721 zone->free_area[order].nr_free = 0;
1722 }
1723}
1724
Andy Whitcroftd41dee32005-06-23 00:07:54 -07001725#define ZONETABLE_INDEX(x, zone_nr) ((x << ZONES_SHIFT) | zone_nr)
1726void zonetable_add(struct zone *zone, int nid, int zid, unsigned long pfn,
1727 unsigned long size)
1728{
1729 unsigned long snum = pfn_to_section_nr(pfn);
1730 unsigned long end = pfn_to_section_nr(pfn + size);
1731
1732 if (FLAGS_HAS_NODE)
1733 zone_table[ZONETABLE_INDEX(nid, zid)] = zone;
1734 else
1735 for (; snum <= end; snum++)
1736 zone_table[ZONETABLE_INDEX(snum, zid)] = zone;
1737}
1738
Linus Torvalds1da177e2005-04-16 15:20:36 -07001739#ifndef __HAVE_ARCH_MEMMAP_INIT
1740#define memmap_init(size, nid, zone, start_pfn) \
1741 memmap_init_zone((size), (nid), (zone), (start_pfn))
1742#endif
1743
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001744static int __devinit zone_batchsize(struct zone *zone)
1745{
1746 int batch;
1747
1748 /*
1749 * The per-cpu-pages pools are set to around 1000th of the
Seth, Rohitba56e912005-10-29 18:15:47 -07001750 * size of the zone. But no more than 1/2 of a meg.
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001751 *
1752 * OK, so we don't know how big the cache is. So guess.
1753 */
1754 batch = zone->present_pages / 1024;
Seth, Rohitba56e912005-10-29 18:15:47 -07001755 if (batch * PAGE_SIZE > 512 * 1024)
1756 batch = (512 * 1024) / PAGE_SIZE;
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001757 batch /= 4; /* We effectively *= 4 below */
1758 if (batch < 1)
1759 batch = 1;
1760
1761 /*
Seth, Rohitba56e912005-10-29 18:15:47 -07001762 * We will be trying to allcoate bigger chunks of contiguous
1763 * memory of the order of fls(batch). This should result in
1764 * better cache coloring.
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001765 *
Seth, Rohitba56e912005-10-29 18:15:47 -07001766 * A sanity check also to ensure that batch is still in limits.
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001767 */
Seth, Rohitba56e912005-10-29 18:15:47 -07001768 batch = (1 << fls(batch + batch/2));
1769
1770 if (fls(batch) >= (PAGE_SHIFT + MAX_ORDER - 2))
1771 batch = PAGE_SHIFT + ((MAX_ORDER - 1 - PAGE_SHIFT)/2);
1772
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001773 return batch;
1774}
1775
Christoph Lameter2caaad42005-06-21 17:15:00 -07001776inline void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
1777{
1778 struct per_cpu_pages *pcp;
1779
Magnus Damm1c6fe942005-10-26 01:58:59 -07001780 memset(p, 0, sizeof(*p));
1781
Christoph Lameter2caaad42005-06-21 17:15:00 -07001782 pcp = &p->pcp[0]; /* hot */
1783 pcp->count = 0;
Seth, Rohite46a5e22005-10-29 18:15:48 -07001784 pcp->low = 0;
Christoph Lameter2caaad42005-06-21 17:15:00 -07001785 pcp->high = 6 * batch;
1786 pcp->batch = max(1UL, 1 * batch);
1787 INIT_LIST_HEAD(&pcp->list);
1788
1789 pcp = &p->pcp[1]; /* cold*/
1790 pcp->count = 0;
1791 pcp->low = 0;
1792 pcp->high = 2 * batch;
Seth, Rohite46a5e22005-10-29 18:15:48 -07001793 pcp->batch = max(1UL, batch/2);
Christoph Lameter2caaad42005-06-21 17:15:00 -07001794 INIT_LIST_HEAD(&pcp->list);
1795}
1796
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001797#ifdef CONFIG_NUMA
1798/*
Christoph Lameter2caaad42005-06-21 17:15:00 -07001799 * Boot pageset table. One per cpu which is going to be used for all
1800 * zones and all nodes. The parameters will be set in such a way
1801 * that an item put on a list will immediately be handed over to
1802 * the buddy list. This is safe since pageset manipulation is done
1803 * with interrupts disabled.
1804 *
1805 * Some NUMA counter updates may also be caught by the boot pagesets.
Christoph Lameterb7c84c62005-06-22 20:26:07 -07001806 *
1807 * The boot_pagesets must be kept even after bootup is complete for
1808 * unused processors and/or zones. They do play a role for bootstrapping
1809 * hotplugged processors.
1810 *
1811 * zoneinfo_show() and maybe other functions do
1812 * not check if the processor is online before following the pageset pointer.
1813 * Other parts of the kernel may not check if the zone is available.
Christoph Lameter2caaad42005-06-21 17:15:00 -07001814 */
1815static struct per_cpu_pageset
Christoph Lameterb7c84c62005-06-22 20:26:07 -07001816 boot_pageset[NR_CPUS];
Christoph Lameter2caaad42005-06-21 17:15:00 -07001817
1818/*
1819 * Dynamically allocate memory for the
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001820 * per cpu pageset array in struct zone.
1821 */
1822static int __devinit process_zones(int cpu)
1823{
1824 struct zone *zone, *dzone;
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001825
1826 for_each_zone(zone) {
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001827
Christoph Lameter2caaad42005-06-21 17:15:00 -07001828 zone->pageset[cpu] = kmalloc_node(sizeof(struct per_cpu_pageset),
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001829 GFP_KERNEL, cpu_to_node(cpu));
Christoph Lameter2caaad42005-06-21 17:15:00 -07001830 if (!zone->pageset[cpu])
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001831 goto bad;
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001832
Christoph Lameter2caaad42005-06-21 17:15:00 -07001833 setup_pageset(zone->pageset[cpu], zone_batchsize(zone));
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07001834 }
1835
1836 return 0;
1837bad:
1838 for_each_zone(dzone) {
1839 if (dzone == zone)
1840 break;
1841 kfree(dzone->pageset[cpu]);
1842 dzone->pageset[cpu] = NULL;
1843 }
1844 return -ENOMEM;
1845}
1846
1847static inline void free_zone_pagesets(int cpu)
1848{
1849#ifdef CONFIG_NUMA
1850 struct zone *zone;
1851
1852 for_each_zone(zone) {
1853 struct per_cpu_pageset *pset = zone_pcp(zone, cpu);
1854
1855 zone_pcp(zone, cpu) = NULL;
1856 kfree(pset);
1857 }
1858#endif
1859}
1860
1861static int __devinit pageset_cpuup_callback(struct notifier_block *nfb,
1862 unsigned long action,
1863 void *hcpu)
1864{
1865 int cpu = (long)hcpu;
1866 int ret = NOTIFY_OK;
1867
1868 switch (action) {
1869 case CPU_UP_PREPARE:
1870 if (process_zones(cpu))
1871 ret = NOTIFY_BAD;
1872 break;
1873#ifdef CONFIG_HOTPLUG_CPU
1874 case CPU_DEAD:
1875 free_zone_pagesets(cpu);
1876 break;
1877#endif
1878 default:
1879 break;
1880 }
1881 return ret;
1882}
1883
1884static struct notifier_block pageset_notifier =
1885 { &pageset_cpuup_callback, NULL, 0 };
1886
1887void __init setup_per_cpu_pageset()
1888{
1889 int err;
1890
1891 /* Initialize per_cpu_pageset for cpu 0.
1892 * A cpuup callback will do this for every cpu
1893 * as it comes online
1894 */
1895 err = process_zones(smp_processor_id());
1896 BUG_ON(err);
1897 register_cpu_notifier(&pageset_notifier);
1898}
1899
1900#endif
1901
Dave Hansened8ece22005-10-29 18:16:50 -07001902static __devinit
1903void zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
1904{
1905 int i;
1906 struct pglist_data *pgdat = zone->zone_pgdat;
1907
1908 /*
1909 * The per-page waitqueue mechanism uses hashed waitqueues
1910 * per zone.
1911 */
1912 zone->wait_table_size = wait_table_size(zone_size_pages);
1913 zone->wait_table_bits = wait_table_bits(zone->wait_table_size);
1914 zone->wait_table = (wait_queue_head_t *)
1915 alloc_bootmem_node(pgdat, zone->wait_table_size
1916 * sizeof(wait_queue_head_t));
1917
1918 for(i = 0; i < zone->wait_table_size; ++i)
1919 init_waitqueue_head(zone->wait_table + i);
1920}
1921
1922static __devinit void zone_pcp_init(struct zone *zone)
1923{
1924 int cpu;
1925 unsigned long batch = zone_batchsize(zone);
1926
1927 for (cpu = 0; cpu < NR_CPUS; cpu++) {
1928#ifdef CONFIG_NUMA
1929 /* Early boot. Slab allocator not functional yet */
1930 zone->pageset[cpu] = &boot_pageset[cpu];
1931 setup_pageset(&boot_pageset[cpu],0);
1932#else
1933 setup_pageset(zone_pcp(zone,cpu), batch);
1934#endif
1935 }
1936 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n",
1937 zone->name, zone->present_pages, batch);
1938}
1939
1940static __devinit void init_currently_empty_zone(struct zone *zone,
1941 unsigned long zone_start_pfn, unsigned long size)
1942{
1943 struct pglist_data *pgdat = zone->zone_pgdat;
1944
1945 zone_wait_table_init(zone, size);
1946 pgdat->nr_zones = zone_idx(zone) + 1;
1947
1948 zone->zone_mem_map = pfn_to_page(zone_start_pfn);
1949 zone->zone_start_pfn = zone_start_pfn;
1950
1951 memmap_init(size, pgdat->node_id, zone_idx(zone), zone_start_pfn);
1952
1953 zone_init_free_lists(pgdat, zone, zone->spanned_pages);
1954}
1955
Linus Torvalds1da177e2005-04-16 15:20:36 -07001956/*
1957 * Set up the zone data structures:
1958 * - mark all pages reserved
1959 * - mark all memory queues empty
1960 * - clear the memory bitmaps
1961 */
1962static void __init free_area_init_core(struct pglist_data *pgdat,
1963 unsigned long *zones_size, unsigned long *zholes_size)
1964{
Dave Hansened8ece22005-10-29 18:16:50 -07001965 unsigned long j;
1966 int nid = pgdat->node_id;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001967 unsigned long zone_start_pfn = pgdat->node_start_pfn;
1968
Dave Hansen208d54e2005-10-29 18:16:52 -07001969 pgdat_resize_init(pgdat);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001970 pgdat->nr_zones = 0;
1971 init_waitqueue_head(&pgdat->kswapd_wait);
1972 pgdat->kswapd_max_order = 0;
1973
1974 for (j = 0; j < MAX_NR_ZONES; j++) {
1975 struct zone *zone = pgdat->node_zones + j;
1976 unsigned long size, realsize;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001977
Linus Torvalds1da177e2005-04-16 15:20:36 -07001978 realsize = size = zones_size[j];
1979 if (zholes_size)
1980 realsize -= zholes_size[j];
1981
1982 if (j == ZONE_DMA || j == ZONE_NORMAL)
1983 nr_kernel_pages += realsize;
1984 nr_all_pages += realsize;
1985
1986 zone->spanned_pages = size;
1987 zone->present_pages = realsize;
1988 zone->name = zone_names[j];
1989 spin_lock_init(&zone->lock);
1990 spin_lock_init(&zone->lru_lock);
Dave Hansenbdc8cb92005-10-29 18:16:53 -07001991 zone_seqlock_init(zone);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001992 zone->zone_pgdat = pgdat;
1993 zone->free_pages = 0;
1994
1995 zone->temp_priority = zone->prev_priority = DEF_PRIORITY;
1996
Dave Hansened8ece22005-10-29 18:16:50 -07001997 zone_pcp_init(zone);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001998 INIT_LIST_HEAD(&zone->active_list);
1999 INIT_LIST_HEAD(&zone->inactive_list);
2000 zone->nr_scan_active = 0;
2001 zone->nr_scan_inactive = 0;
2002 zone->nr_active = 0;
2003 zone->nr_inactive = 0;
Martin Hicks53e9a612005-09-03 15:54:51 -07002004 atomic_set(&zone->reclaim_in_progress, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002005 if (!size)
2006 continue;
2007
Andy Whitcroftd41dee32005-06-23 00:07:54 -07002008 zonetable_add(zone, nid, j, zone_start_pfn, size);
Dave Hansened8ece22005-10-29 18:16:50 -07002009 init_currently_empty_zone(zone, zone_start_pfn, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002010 zone_start_pfn += size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002011 }
2012}
2013
2014static void __init alloc_node_mem_map(struct pglist_data *pgdat)
2015{
Linus Torvalds1da177e2005-04-16 15:20:36 -07002016 /* Skip empty nodes */
2017 if (!pgdat->node_spanned_pages)
2018 return;
2019
Andy Whitcroftd41dee32005-06-23 00:07:54 -07002020#ifdef CONFIG_FLAT_NODE_MEM_MAP
Linus Torvalds1da177e2005-04-16 15:20:36 -07002021 /* ia64 gets its own node_mem_map, before this, without bootmem */
2022 if (!pgdat->node_mem_map) {
Andy Whitcroftd41dee32005-06-23 00:07:54 -07002023 unsigned long size;
2024 struct page *map;
2025
Linus Torvalds1da177e2005-04-16 15:20:36 -07002026 size = (pgdat->node_spanned_pages + 1) * sizeof(struct page);
Dave Hansen6f167ec2005-06-23 00:07:39 -07002027 map = alloc_remap(pgdat->node_id, size);
2028 if (!map)
2029 map = alloc_bootmem_node(pgdat, size);
2030 pgdat->node_mem_map = map;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002031 }
Andy Whitcroftd41dee32005-06-23 00:07:54 -07002032#ifdef CONFIG_FLATMEM
Linus Torvalds1da177e2005-04-16 15:20:36 -07002033 /*
2034 * With no DISCONTIG, the global mem_map is just set as node 0's
2035 */
2036 if (pgdat == NODE_DATA(0))
2037 mem_map = NODE_DATA(0)->node_mem_map;
2038#endif
Andy Whitcroftd41dee32005-06-23 00:07:54 -07002039#endif /* CONFIG_FLAT_NODE_MEM_MAP */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002040}
2041
2042void __init free_area_init_node(int nid, struct pglist_data *pgdat,
2043 unsigned long *zones_size, unsigned long node_start_pfn,
2044 unsigned long *zholes_size)
2045{
2046 pgdat->node_id = nid;
2047 pgdat->node_start_pfn = node_start_pfn;
2048 calculate_zone_totalpages(pgdat, zones_size, zholes_size);
2049
2050 alloc_node_mem_map(pgdat);
2051
2052 free_area_init_core(pgdat, zones_size, zholes_size);
2053}
2054
Dave Hansen93b75042005-06-23 00:07:47 -07002055#ifndef CONFIG_NEED_MULTIPLE_NODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07002056static bootmem_data_t contig_bootmem_data;
2057struct pglist_data contig_page_data = { .bdata = &contig_bootmem_data };
2058
2059EXPORT_SYMBOL(contig_page_data);
Dave Hansen93b75042005-06-23 00:07:47 -07002060#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002061
2062void __init free_area_init(unsigned long *zones_size)
2063{
Dave Hansen93b75042005-06-23 00:07:47 -07002064 free_area_init_node(0, NODE_DATA(0), zones_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002065 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
2066}
Linus Torvalds1da177e2005-04-16 15:20:36 -07002067
2068#ifdef CONFIG_PROC_FS
2069
2070#include <linux/seq_file.h>
2071
2072static void *frag_start(struct seq_file *m, loff_t *pos)
2073{
2074 pg_data_t *pgdat;
2075 loff_t node = *pos;
2076
2077 for (pgdat = pgdat_list; pgdat && node; pgdat = pgdat->pgdat_next)
2078 --node;
2079
2080 return pgdat;
2081}
2082
2083static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
2084{
2085 pg_data_t *pgdat = (pg_data_t *)arg;
2086
2087 (*pos)++;
2088 return pgdat->pgdat_next;
2089}
2090
2091static void frag_stop(struct seq_file *m, void *arg)
2092{
2093}
2094
2095/*
2096 * This walks the free areas for each zone.
2097 */
2098static int frag_show(struct seq_file *m, void *arg)
2099{
2100 pg_data_t *pgdat = (pg_data_t *)arg;
2101 struct zone *zone;
2102 struct zone *node_zones = pgdat->node_zones;
2103 unsigned long flags;
2104 int order;
2105
2106 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
2107 if (!zone->present_pages)
2108 continue;
2109
2110 spin_lock_irqsave(&zone->lock, flags);
2111 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
2112 for (order = 0; order < MAX_ORDER; ++order)
2113 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
2114 spin_unlock_irqrestore(&zone->lock, flags);
2115 seq_putc(m, '\n');
2116 }
2117 return 0;
2118}
2119
2120struct seq_operations fragmentation_op = {
2121 .start = frag_start,
2122 .next = frag_next,
2123 .stop = frag_stop,
2124 .show = frag_show,
2125};
2126
Nikita Danilov295ab932005-06-21 17:14:38 -07002127/*
2128 * Output information about zones in @pgdat.
2129 */
2130static int zoneinfo_show(struct seq_file *m, void *arg)
2131{
2132 pg_data_t *pgdat = arg;
2133 struct zone *zone;
2134 struct zone *node_zones = pgdat->node_zones;
2135 unsigned long flags;
2136
2137 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; zone++) {
2138 int i;
2139
2140 if (!zone->present_pages)
2141 continue;
2142
2143 spin_lock_irqsave(&zone->lock, flags);
2144 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
2145 seq_printf(m,
2146 "\n pages free %lu"
2147 "\n min %lu"
2148 "\n low %lu"
2149 "\n high %lu"
2150 "\n active %lu"
2151 "\n inactive %lu"
2152 "\n scanned %lu (a: %lu i: %lu)"
2153 "\n spanned %lu"
2154 "\n present %lu",
2155 zone->free_pages,
2156 zone->pages_min,
2157 zone->pages_low,
2158 zone->pages_high,
2159 zone->nr_active,
2160 zone->nr_inactive,
2161 zone->pages_scanned,
2162 zone->nr_scan_active, zone->nr_scan_inactive,
2163 zone->spanned_pages,
2164 zone->present_pages);
2165 seq_printf(m,
2166 "\n protection: (%lu",
2167 zone->lowmem_reserve[0]);
2168 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
2169 seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
2170 seq_printf(m,
2171 ")"
2172 "\n pagesets");
2173 for (i = 0; i < ARRAY_SIZE(zone->pageset); i++) {
2174 struct per_cpu_pageset *pageset;
2175 int j;
2176
Christoph Lametere7c8d5c2005-06-21 17:14:47 -07002177 pageset = zone_pcp(zone, i);
Nikita Danilov295ab932005-06-21 17:14:38 -07002178 for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {
2179 if (pageset->pcp[j].count)
2180 break;
2181 }
2182 if (j == ARRAY_SIZE(pageset->pcp))
2183 continue;
2184 for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {
2185 seq_printf(m,
2186 "\n cpu: %i pcp: %i"
2187 "\n count: %i"
2188 "\n low: %i"
2189 "\n high: %i"
2190 "\n batch: %i",
2191 i, j,
2192 pageset->pcp[j].count,
2193 pageset->pcp[j].low,
2194 pageset->pcp[j].high,
2195 pageset->pcp[j].batch);
2196 }
2197#ifdef CONFIG_NUMA
2198 seq_printf(m,
2199 "\n numa_hit: %lu"
2200 "\n numa_miss: %lu"
2201 "\n numa_foreign: %lu"
2202 "\n interleave_hit: %lu"
2203 "\n local_node: %lu"
2204 "\n other_node: %lu",
2205 pageset->numa_hit,
2206 pageset->numa_miss,
2207 pageset->numa_foreign,
2208 pageset->interleave_hit,
2209 pageset->local_node,
2210 pageset->other_node);
2211#endif
2212 }
2213 seq_printf(m,
2214 "\n all_unreclaimable: %u"
2215 "\n prev_priority: %i"
2216 "\n temp_priority: %i"
2217 "\n start_pfn: %lu",
2218 zone->all_unreclaimable,
2219 zone->prev_priority,
2220 zone->temp_priority,
2221 zone->zone_start_pfn);
2222 spin_unlock_irqrestore(&zone->lock, flags);
2223 seq_putc(m, '\n');
2224 }
2225 return 0;
2226}
2227
2228struct seq_operations zoneinfo_op = {
2229 .start = frag_start, /* iterate over all zones. The same as in
2230 * fragmentation. */
2231 .next = frag_next,
2232 .stop = frag_stop,
2233 .show = zoneinfo_show,
2234};
2235
Linus Torvalds1da177e2005-04-16 15:20:36 -07002236static char *vmstat_text[] = {
2237 "nr_dirty",
2238 "nr_writeback",
2239 "nr_unstable",
2240 "nr_page_table_pages",
2241 "nr_mapped",
2242 "nr_slab",
2243
2244 "pgpgin",
2245 "pgpgout",
2246 "pswpin",
2247 "pswpout",
2248 "pgalloc_high",
2249
2250 "pgalloc_normal",
2251 "pgalloc_dma",
2252 "pgfree",
2253 "pgactivate",
2254 "pgdeactivate",
2255
2256 "pgfault",
2257 "pgmajfault",
2258 "pgrefill_high",
2259 "pgrefill_normal",
2260 "pgrefill_dma",
2261
2262 "pgsteal_high",
2263 "pgsteal_normal",
2264 "pgsteal_dma",
2265 "pgscan_kswapd_high",
2266 "pgscan_kswapd_normal",
2267
2268 "pgscan_kswapd_dma",
2269 "pgscan_direct_high",
2270 "pgscan_direct_normal",
2271 "pgscan_direct_dma",
2272 "pginodesteal",
2273
2274 "slabs_scanned",
2275 "kswapd_steal",
2276 "kswapd_inodesteal",
2277 "pageoutrun",
2278 "allocstall",
2279
2280 "pgrotated",
KAMEZAWA Hiroyukiedfbe2b2005-05-01 08:58:37 -07002281 "nr_bounce",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002282};
2283
2284static void *vmstat_start(struct seq_file *m, loff_t *pos)
2285{
2286 struct page_state *ps;
2287
2288 if (*pos >= ARRAY_SIZE(vmstat_text))
2289 return NULL;
2290
2291 ps = kmalloc(sizeof(*ps), GFP_KERNEL);
2292 m->private = ps;
2293 if (!ps)
2294 return ERR_PTR(-ENOMEM);
2295 get_full_page_state(ps);
2296 ps->pgpgin /= 2; /* sectors -> kbytes */
2297 ps->pgpgout /= 2;
2298 return (unsigned long *)ps + *pos;
2299}
2300
2301static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
2302{
2303 (*pos)++;
2304 if (*pos >= ARRAY_SIZE(vmstat_text))
2305 return NULL;
2306 return (unsigned long *)m->private + *pos;
2307}
2308
2309static int vmstat_show(struct seq_file *m, void *arg)
2310{
2311 unsigned long *l = arg;
2312 unsigned long off = l - (unsigned long *)m->private;
2313
2314 seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
2315 return 0;
2316}
2317
2318static void vmstat_stop(struct seq_file *m, void *arg)
2319{
2320 kfree(m->private);
2321 m->private = NULL;
2322}
2323
2324struct seq_operations vmstat_op = {
2325 .start = vmstat_start,
2326 .next = vmstat_next,
2327 .stop = vmstat_stop,
2328 .show = vmstat_show,
2329};
2330
2331#endif /* CONFIG_PROC_FS */
2332
2333#ifdef CONFIG_HOTPLUG_CPU
2334static int page_alloc_cpu_notify(struct notifier_block *self,
2335 unsigned long action, void *hcpu)
2336{
2337 int cpu = (unsigned long)hcpu;
2338 long *count;
2339 unsigned long *src, *dest;
2340
2341 if (action == CPU_DEAD) {
2342 int i;
2343
2344 /* Drain local pagecache count. */
2345 count = &per_cpu(nr_pagecache_local, cpu);
2346 atomic_add(*count, &nr_pagecache);
2347 *count = 0;
2348 local_irq_disable();
2349 __drain_pages(cpu);
2350
2351 /* Add dead cpu's page_states to our own. */
2352 dest = (unsigned long *)&__get_cpu_var(page_states);
2353 src = (unsigned long *)&per_cpu(page_states, cpu);
2354
2355 for (i = 0; i < sizeof(struct page_state)/sizeof(unsigned long);
2356 i++) {
2357 dest[i] += src[i];
2358 src[i] = 0;
2359 }
2360
2361 local_irq_enable();
2362 }
2363 return NOTIFY_OK;
2364}
2365#endif /* CONFIG_HOTPLUG_CPU */
2366
2367void __init page_alloc_init(void)
2368{
2369 hotcpu_notifier(page_alloc_cpu_notify, 0);
2370}
2371
2372/*
2373 * setup_per_zone_lowmem_reserve - called whenever
2374 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
2375 * has a correct pages reserved value, so an adequate number of
2376 * pages are left in the zone after a successful __alloc_pages().
2377 */
2378static void setup_per_zone_lowmem_reserve(void)
2379{
2380 struct pglist_data *pgdat;
2381 int j, idx;
2382
2383 for_each_pgdat(pgdat) {
2384 for (j = 0; j < MAX_NR_ZONES; j++) {
2385 struct zone *zone = pgdat->node_zones + j;
2386 unsigned long present_pages = zone->present_pages;
2387
2388 zone->lowmem_reserve[j] = 0;
2389
2390 for (idx = j-1; idx >= 0; idx--) {
2391 struct zone *lower_zone;
2392
2393 if (sysctl_lowmem_reserve_ratio[idx] < 1)
2394 sysctl_lowmem_reserve_ratio[idx] = 1;
2395
2396 lower_zone = pgdat->node_zones + idx;
2397 lower_zone->lowmem_reserve[j] = present_pages /
2398 sysctl_lowmem_reserve_ratio[idx];
2399 present_pages += lower_zone->present_pages;
2400 }
2401 }
2402 }
2403}
2404
2405/*
2406 * setup_per_zone_pages_min - called when min_free_kbytes changes. Ensures
2407 * that the pages_{min,low,high} values for each zone are set correctly
2408 * with respect to min_free_kbytes.
2409 */
Dave Hansen3947be12005-10-29 18:16:54 -07002410void setup_per_zone_pages_min(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002411{
2412 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
2413 unsigned long lowmem_pages = 0;
2414 struct zone *zone;
2415 unsigned long flags;
2416
2417 /* Calculate total number of !ZONE_HIGHMEM pages */
2418 for_each_zone(zone) {
2419 if (!is_highmem(zone))
2420 lowmem_pages += zone->present_pages;
2421 }
2422
2423 for_each_zone(zone) {
2424 spin_lock_irqsave(&zone->lru_lock, flags);
2425 if (is_highmem(zone)) {
2426 /*
2427 * Often, highmem doesn't need to reserve any pages.
2428 * But the pages_min/low/high values are also used for
2429 * batching up page reclaim activity so we need a
2430 * decent value here.
2431 */
2432 int min_pages;
2433
2434 min_pages = zone->present_pages / 1024;
2435 if (min_pages < SWAP_CLUSTER_MAX)
2436 min_pages = SWAP_CLUSTER_MAX;
2437 if (min_pages > 128)
2438 min_pages = 128;
2439 zone->pages_min = min_pages;
2440 } else {
Nikita Danilov295ab932005-06-21 17:14:38 -07002441 /* if it's a lowmem zone, reserve a number of pages
Linus Torvalds1da177e2005-04-16 15:20:36 -07002442 * proportionate to the zone's size.
2443 */
Nikita Danilov295ab932005-06-21 17:14:38 -07002444 zone->pages_min = (pages_min * zone->present_pages) /
Linus Torvalds1da177e2005-04-16 15:20:36 -07002445 lowmem_pages;
2446 }
2447
2448 /*
2449 * When interpreting these watermarks, just keep in mind that:
2450 * zone->pages_min == (zone->pages_min * 4) / 4;
2451 */
2452 zone->pages_low = (zone->pages_min * 5) / 4;
2453 zone->pages_high = (zone->pages_min * 6) / 4;
2454 spin_unlock_irqrestore(&zone->lru_lock, flags);
2455 }
2456}
2457
2458/*
2459 * Initialise min_free_kbytes.
2460 *
2461 * For small machines we want it small (128k min). For large machines
2462 * we want it large (64MB max). But it is not linear, because network
2463 * bandwidth does not increase linearly with machine size. We use
2464 *
2465 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
2466 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
2467 *
2468 * which yields
2469 *
2470 * 16MB: 512k
2471 * 32MB: 724k
2472 * 64MB: 1024k
2473 * 128MB: 1448k
2474 * 256MB: 2048k
2475 * 512MB: 2896k
2476 * 1024MB: 4096k
2477 * 2048MB: 5792k
2478 * 4096MB: 8192k
2479 * 8192MB: 11584k
2480 * 16384MB: 16384k
2481 */
2482static int __init init_per_zone_pages_min(void)
2483{
2484 unsigned long lowmem_kbytes;
2485
2486 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
2487
2488 min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
2489 if (min_free_kbytes < 128)
2490 min_free_kbytes = 128;
2491 if (min_free_kbytes > 65536)
2492 min_free_kbytes = 65536;
2493 setup_per_zone_pages_min();
2494 setup_per_zone_lowmem_reserve();
2495 return 0;
2496}
2497module_init(init_per_zone_pages_min)
2498
2499/*
2500 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
2501 * that we can call two helper functions whenever min_free_kbytes
2502 * changes.
2503 */
2504int min_free_kbytes_sysctl_handler(ctl_table *table, int write,
2505 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
2506{
2507 proc_dointvec(table, write, file, buffer, length, ppos);
2508 setup_per_zone_pages_min();
2509 return 0;
2510}
2511
2512/*
2513 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
2514 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
2515 * whenever sysctl_lowmem_reserve_ratio changes.
2516 *
2517 * The reserve ratio obviously has absolutely no relation with the
2518 * pages_min watermarks. The lowmem reserve ratio can only make sense
2519 * if in function of the boot time zone sizes.
2520 */
2521int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
2522 struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
2523{
2524 proc_dointvec_minmax(table, write, file, buffer, length, ppos);
2525 setup_per_zone_lowmem_reserve();
2526 return 0;
2527}
2528
2529__initdata int hashdist = HASHDIST_DEFAULT;
2530
2531#ifdef CONFIG_NUMA
2532static int __init set_hashdist(char *str)
2533{
2534 if (!str)
2535 return 0;
2536 hashdist = simple_strtoul(str, &str, 0);
2537 return 1;
2538}
2539__setup("hashdist=", set_hashdist);
2540#endif
2541
2542/*
2543 * allocate a large system hash table from bootmem
2544 * - it is assumed that the hash table must contain an exact power-of-2
2545 * quantity of entries
2546 * - limit is the number of hash buckets, not the total allocation size
2547 */
2548void *__init alloc_large_system_hash(const char *tablename,
2549 unsigned long bucketsize,
2550 unsigned long numentries,
2551 int scale,
2552 int flags,
2553 unsigned int *_hash_shift,
2554 unsigned int *_hash_mask,
2555 unsigned long limit)
2556{
2557 unsigned long long max = limit;
2558 unsigned long log2qty, size;
2559 void *table = NULL;
2560
2561 /* allow the kernel cmdline to have a say */
2562 if (!numentries) {
2563 /* round applicable memory size up to nearest megabyte */
2564 numentries = (flags & HASH_HIGHMEM) ? nr_all_pages : nr_kernel_pages;
2565 numentries += (1UL << (20 - PAGE_SHIFT)) - 1;
2566 numentries >>= 20 - PAGE_SHIFT;
2567 numentries <<= 20 - PAGE_SHIFT;
2568
2569 /* limit to 1 bucket per 2^scale bytes of low memory */
2570 if (scale > PAGE_SHIFT)
2571 numentries >>= (scale - PAGE_SHIFT);
2572 else
2573 numentries <<= (PAGE_SHIFT - scale);
2574 }
2575 /* rounded up to nearest power of 2 in size */
2576 numentries = 1UL << (long_log2(numentries) + 1);
2577
2578 /* limit allocation size to 1/16 total memory by default */
2579 if (max == 0) {
2580 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
2581 do_div(max, bucketsize);
2582 }
2583
2584 if (numentries > max)
2585 numentries = max;
2586
2587 log2qty = long_log2(numentries);
2588
2589 do {
2590 size = bucketsize << log2qty;
2591 if (flags & HASH_EARLY)
2592 table = alloc_bootmem(size);
2593 else if (hashdist)
2594 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
2595 else {
2596 unsigned long order;
2597 for (order = 0; ((1UL << order) << PAGE_SHIFT) < size; order++)
2598 ;
2599 table = (void*) __get_free_pages(GFP_ATOMIC, order);
2600 }
2601 } while (!table && size > PAGE_SIZE && --log2qty);
2602
2603 if (!table)
2604 panic("Failed to allocate %s hash table\n", tablename);
2605
2606 printk("%s hash table entries: %d (order: %d, %lu bytes)\n",
2607 tablename,
2608 (1U << log2qty),
2609 long_log2(size) - PAGE_SHIFT,
2610 size);
2611
2612 if (_hash_shift)
2613 *_hash_shift = log2qty;
2614 if (_hash_mask)
2615 *_hash_mask = (1 << log2qty) - 1;
2616
2617 return table;
2618}