2 * linux/mm/page_alloc.c
4 * Manages the free list, the system allocates free pages here.
5 * Note that kmalloc() lives in slab.c
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)
17 #include <linux/stddef.h>
19 #include <linux/swap.h>
20 #include <linux/interrupt.h>
21 #include <linux/pagemap.h>
22 #include <linux/jiffies.h>
23 #include <linux/bootmem.h>
24 #include <linux/memblock.h>
25 #include <linux/compiler.h>
26 #include <linux/kernel.h>
27 #include <linux/kmemcheck.h>
28 #include <linux/module.h>
29 #include <linux/suspend.h>
30 #include <linux/pagevec.h>
31 #include <linux/blkdev.h>
32 #include <linux/slab.h>
33 #include <linux/oom.h>
34 #include <linux/notifier.h>
35 #include <linux/topology.h>
36 #include <linux/sysctl.h>
37 #include <linux/cpu.h>
38 #include <linux/cpuset.h>
39 #include <linux/memory_hotplug.h>
40 #include <linux/nodemask.h>
41 #include <linux/vmalloc.h>
42 #include <linux/mempolicy.h>
43 #include <linux/stop_machine.h>
44 #include <linux/sort.h>
45 #include <linux/pfn.h>
46 #include <linux/backing-dev.h>
47 #include <linux/fault-inject.h>
48 #include <linux/page-isolation.h>
49 #include <linux/page_cgroup.h>
50 #include <linux/debugobjects.h>
51 #include <linux/kmemleak.h>
52 #include <linux/memory.h>
53 #include <linux/compaction.h>
54 #include <trace/events/kmem.h>
55 #include <linux/ftrace_event.h>
57 #include <asm/tlbflush.h>
58 #include <asm/div64.h>
61 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
62 DEFINE_PER_CPU(int, numa_node
);
63 EXPORT_PER_CPU_SYMBOL(numa_node
);
66 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
68 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
69 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
70 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
71 * defined in <linux/topology.h>.
73 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
74 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
78 * Array of node states.
80 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
81 [N_POSSIBLE
] = NODE_MASK_ALL
,
82 [N_ONLINE
] = { { [0] = 1UL } },
84 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
86 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
88 [N_CPU
] = { { [0] = 1UL } },
91 EXPORT_SYMBOL(node_states
);
93 unsigned long totalram_pages __read_mostly
;
94 unsigned long totalreserve_pages __read_mostly
;
95 int percpu_pagelist_fraction
;
96 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
98 #ifdef CONFIG_PM_SLEEP
100 * The following functions are used by the suspend/hibernate code to temporarily
101 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
102 * while devices are suspended. To avoid races with the suspend/hibernate code,
103 * they should always be called with pm_mutex held (gfp_allowed_mask also should
104 * only be modified with pm_mutex held, unless the suspend/hibernate code is
105 * guaranteed not to run in parallel with that modification).
107 void set_gfp_allowed_mask(gfp_t mask
)
109 WARN_ON(!mutex_is_locked(&pm_mutex
));
110 gfp_allowed_mask
= mask
;
113 gfp_t
clear_gfp_allowed_mask(gfp_t mask
)
115 gfp_t ret
= gfp_allowed_mask
;
117 WARN_ON(!mutex_is_locked(&pm_mutex
));
118 gfp_allowed_mask
&= ~mask
;
121 #endif /* CONFIG_PM_SLEEP */
123 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
124 int pageblock_order __read_mostly
;
127 static void __free_pages_ok(struct page
*page
, unsigned int order
);
130 * results with 256, 32 in the lowmem_reserve sysctl:
131 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
132 * 1G machine -> (16M dma, 784M normal, 224M high)
133 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
134 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
135 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
137 * TBD: should special case ZONE_DMA32 machines here - in those we normally
138 * don't need any ZONE_NORMAL reservation
140 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
141 #ifdef CONFIG_ZONE_DMA
144 #ifdef CONFIG_ZONE_DMA32
147 #ifdef CONFIG_HIGHMEM
153 EXPORT_SYMBOL(totalram_pages
);
155 static char * const zone_names
[MAX_NR_ZONES
] = {
156 #ifdef CONFIG_ZONE_DMA
159 #ifdef CONFIG_ZONE_DMA32
163 #ifdef CONFIG_HIGHMEM
169 int min_free_kbytes
= 1024;
171 static unsigned long __meminitdata nr_kernel_pages
;
172 static unsigned long __meminitdata nr_all_pages
;
173 static unsigned long __meminitdata dma_reserve
;
175 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
177 * MAX_ACTIVE_REGIONS determines the maximum number of distinct
178 * ranges of memory (RAM) that may be registered with add_active_range().
179 * Ranges passed to add_active_range() will be merged if possible
180 * so the number of times add_active_range() can be called is
181 * related to the number of nodes and the number of holes
183 #ifdef CONFIG_MAX_ACTIVE_REGIONS
184 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */
185 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS
187 #if MAX_NUMNODES >= 32
188 /* If there can be many nodes, allow up to 50 holes per node */
189 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50)
191 /* By default, allow up to 256 distinct regions */
192 #define MAX_ACTIVE_REGIONS 256
196 static struct node_active_region __meminitdata early_node_map
[MAX_ACTIVE_REGIONS
];
197 static int __meminitdata nr_nodemap_entries
;
198 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
199 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
200 static unsigned long __initdata required_kernelcore
;
201 static unsigned long __initdata required_movablecore
;
202 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
204 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
206 EXPORT_SYMBOL(movable_zone
);
207 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
210 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
211 int nr_online_nodes __read_mostly
= 1;
212 EXPORT_SYMBOL(nr_node_ids
);
213 EXPORT_SYMBOL(nr_online_nodes
);
216 int page_group_by_mobility_disabled __read_mostly
;
218 static void set_pageblock_migratetype(struct page
*page
, int migratetype
)
221 if (unlikely(page_group_by_mobility_disabled
))
222 migratetype
= MIGRATE_UNMOVABLE
;
224 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
225 PB_migrate
, PB_migrate_end
);
228 bool oom_killer_disabled __read_mostly
;
230 #ifdef CONFIG_DEBUG_VM
231 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
235 unsigned long pfn
= page_to_pfn(page
);
238 seq
= zone_span_seqbegin(zone
);
239 if (pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
241 else if (pfn
< zone
->zone_start_pfn
)
243 } while (zone_span_seqretry(zone
, seq
));
248 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
250 if (!pfn_valid_within(page_to_pfn(page
)))
252 if (zone
!= page_zone(page
))
258 * Temporary debugging check for pages not lying within a given zone.
260 static int bad_range(struct zone
*zone
, struct page
*page
)
262 if (page_outside_zone_boundaries(zone
, page
))
264 if (!page_is_consistent(zone
, page
))
270 static inline int bad_range(struct zone
*zone
, struct page
*page
)
276 static void bad_page(struct page
*page
)
278 static unsigned long resume
;
279 static unsigned long nr_shown
;
280 static unsigned long nr_unshown
;
282 /* Don't complain about poisoned pages */
283 if (PageHWPoison(page
)) {
284 __ClearPageBuddy(page
);
289 * Allow a burst of 60 reports, then keep quiet for that minute;
290 * or allow a steady drip of one report per second.
292 if (nr_shown
== 60) {
293 if (time_before(jiffies
, resume
)) {
299 "BUG: Bad page state: %lu messages suppressed\n",
306 resume
= jiffies
+ 60 * HZ
;
308 printk(KERN_ALERT
"BUG: Bad page state in process %s pfn:%05lx\n",
309 current
->comm
, page_to_pfn(page
));
314 /* Leave bad fields for debug, except PageBuddy could make trouble */
315 __ClearPageBuddy(page
);
316 add_taint(TAINT_BAD_PAGE
);
320 * Higher-order pages are called "compound pages". They are structured thusly:
322 * The first PAGE_SIZE page is called the "head page".
324 * The remaining PAGE_SIZE pages are called "tail pages".
326 * All pages have PG_compound set. All pages have their ->private pointing at
327 * the head page (even the head page has this).
329 * The first tail page's ->lru.next holds the address of the compound page's
330 * put_page() function. Its ->lru.prev holds the order of allocation.
331 * This usage means that zero-order pages may not be compound.
334 static void free_compound_page(struct page
*page
)
336 __free_pages_ok(page
, compound_order(page
));
339 void prep_compound_page(struct page
*page
, unsigned long order
)
342 int nr_pages
= 1 << order
;
344 set_compound_page_dtor(page
, free_compound_page
);
345 set_compound_order(page
, order
);
347 for (i
= 1; i
< nr_pages
; i
++) {
348 struct page
*p
= page
+ i
;
351 p
->first_page
= page
;
355 static int destroy_compound_page(struct page
*page
, unsigned long order
)
358 int nr_pages
= 1 << order
;
361 if (unlikely(compound_order(page
) != order
) ||
362 unlikely(!PageHead(page
))) {
367 __ClearPageHead(page
);
369 for (i
= 1; i
< nr_pages
; i
++) {
370 struct page
*p
= page
+ i
;
372 if (unlikely(!PageTail(p
) || (p
->first_page
!= page
))) {
382 static inline void prep_zero_page(struct page
*page
, int order
, gfp_t gfp_flags
)
387 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
388 * and __GFP_HIGHMEM from hard or soft interrupt context.
390 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
391 for (i
= 0; i
< (1 << order
); i
++)
392 clear_highpage(page
+ i
);
395 static inline void set_page_order(struct page
*page
, int order
)
397 set_page_private(page
, order
);
398 __SetPageBuddy(page
);
401 static inline void rmv_page_order(struct page
*page
)
403 __ClearPageBuddy(page
);
404 set_page_private(page
, 0);
408 * Locate the struct page for both the matching buddy in our
409 * pair (buddy1) and the combined O(n+1) page they form (page).
411 * 1) Any buddy B1 will have an order O twin B2 which satisfies
412 * the following equation:
414 * For example, if the starting buddy (buddy2) is #8 its order
416 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
418 * 2) Any buddy B will have an order O+1 parent P which
419 * satisfies the following equation:
422 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
424 static inline struct page
*
425 __page_find_buddy(struct page
*page
, unsigned long page_idx
, unsigned int order
)
427 unsigned long buddy_idx
= page_idx
^ (1 << order
);
429 return page
+ (buddy_idx
- page_idx
);
432 static inline unsigned long
433 __find_combined_index(unsigned long page_idx
, unsigned int order
)
435 return (page_idx
& ~(1 << order
));
439 * This function checks whether a page is free && is the buddy
440 * we can do coalesce a page and its buddy if
441 * (a) the buddy is not in a hole &&
442 * (b) the buddy is in the buddy system &&
443 * (c) a page and its buddy have the same order &&
444 * (d) a page and its buddy are in the same zone.
446 * For recording whether a page is in the buddy system, we use PG_buddy.
447 * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
449 * For recording page's order, we use page_private(page).
451 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
454 if (!pfn_valid_within(page_to_pfn(buddy
)))
457 if (page_zone_id(page
) != page_zone_id(buddy
))
460 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
461 VM_BUG_ON(page_count(buddy
) != 0);
468 * Freeing function for a buddy system allocator.
470 * The concept of a buddy system is to maintain direct-mapped table
471 * (containing bit values) for memory blocks of various "orders".
472 * The bottom level table contains the map for the smallest allocatable
473 * units of memory (here, pages), and each level above it describes
474 * pairs of units from the levels below, hence, "buddies".
475 * At a high level, all that happens here is marking the table entry
476 * at the bottom level available, and propagating the changes upward
477 * as necessary, plus some accounting needed to play nicely with other
478 * parts of the VM system.
479 * At each level, we keep a list of pages, which are heads of continuous
480 * free pages of length of (1 << order) and marked with PG_buddy. Page's
481 * order is recorded in page_private(page) field.
482 * So when we are allocating or freeing one, we can derive the state of the
483 * other. That is, if we allocate a small block, and both were
484 * free, the remainder of the region must be split into blocks.
485 * If a block is freed, and its buddy is also free, then this
486 * triggers coalescing into a block of larger size.
491 static inline void __free_one_page(struct page
*page
,
492 struct zone
*zone
, unsigned int order
,
495 unsigned long page_idx
;
496 unsigned long combined_idx
;
499 if (unlikely(PageCompound(page
)))
500 if (unlikely(destroy_compound_page(page
, order
)))
503 VM_BUG_ON(migratetype
== -1);
505 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
507 VM_BUG_ON(page_idx
& ((1 << order
) - 1));
508 VM_BUG_ON(bad_range(zone
, page
));
510 while (order
< MAX_ORDER
-1) {
511 buddy
= __page_find_buddy(page
, page_idx
, order
);
512 if (!page_is_buddy(page
, buddy
, order
))
515 /* Our buddy is free, merge with it and move up one order. */
516 list_del(&buddy
->lru
);
517 zone
->free_area
[order
].nr_free
--;
518 rmv_page_order(buddy
);
519 combined_idx
= __find_combined_index(page_idx
, order
);
520 page
= page
+ (combined_idx
- page_idx
);
521 page_idx
= combined_idx
;
524 set_page_order(page
, order
);
527 * If this is not the largest possible page, check if the buddy
528 * of the next-highest order is free. If it is, it's possible
529 * that pages are being freed that will coalesce soon. In case,
530 * that is happening, add the free page to the tail of the list
531 * so it's less likely to be used soon and more likely to be merged
532 * as a higher order page
534 if ((order
< MAX_ORDER
-1) && pfn_valid_within(page_to_pfn(buddy
))) {
535 struct page
*higher_page
, *higher_buddy
;
536 combined_idx
= __find_combined_index(page_idx
, order
);
537 higher_page
= page
+ combined_idx
- page_idx
;
538 higher_buddy
= __page_find_buddy(higher_page
, combined_idx
, order
+ 1);
539 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
540 list_add_tail(&page
->lru
,
541 &zone
->free_area
[order
].free_list
[migratetype
]);
546 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
548 zone
->free_area
[order
].nr_free
++;
552 * free_page_mlock() -- clean up attempts to free and mlocked() page.
553 * Page should not be on lru, so no need to fix that up.
554 * free_pages_check() will verify...
556 static inline void free_page_mlock(struct page
*page
)
558 __dec_zone_page_state(page
, NR_MLOCK
);
559 __count_vm_event(UNEVICTABLE_MLOCKFREED
);
562 static inline int free_pages_check(struct page
*page
)
564 if (unlikely(page_mapcount(page
) |
565 (page
->mapping
!= NULL
) |
566 (atomic_read(&page
->_count
) != 0) |
567 (page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
))) {
571 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
572 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
577 * Frees a number of pages from the PCP lists
578 * Assumes all pages on list are in same zone, and of same order.
579 * count is the number of pages to free.
581 * If the zone was previously in an "all pages pinned" state then look to
582 * see if this freeing clears that state.
584 * And clear the zone's pages_scanned counter, to hold off the "all pages are
585 * pinned" detection logic.
587 static void free_pcppages_bulk(struct zone
*zone
, int count
,
588 struct per_cpu_pages
*pcp
)
593 spin_lock(&zone
->lock
);
594 zone
->all_unreclaimable
= 0;
595 zone
->pages_scanned
= 0;
597 __mod_zone_page_state(zone
, NR_FREE_PAGES
, count
);
600 struct list_head
*list
;
603 * Remove pages from lists in a round-robin fashion. A
604 * batch_free count is maintained that is incremented when an
605 * empty list is encountered. This is so more pages are freed
606 * off fuller lists instead of spinning excessively around empty
611 if (++migratetype
== MIGRATE_PCPTYPES
)
613 list
= &pcp
->lists
[migratetype
];
614 } while (list_empty(list
));
617 page
= list_entry(list
->prev
, struct page
, lru
);
618 /* must delete as __free_one_page list manipulates */
619 list_del(&page
->lru
);
620 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
621 __free_one_page(page
, zone
, 0, page_private(page
));
622 trace_mm_page_pcpu_drain(page
, 0, page_private(page
));
623 } while (--count
&& --batch_free
&& !list_empty(list
));
625 spin_unlock(&zone
->lock
);
628 static void free_one_page(struct zone
*zone
, struct page
*page
, int order
,
631 spin_lock(&zone
->lock
);
632 zone
->all_unreclaimable
= 0;
633 zone
->pages_scanned
= 0;
635 __mod_zone_page_state(zone
, NR_FREE_PAGES
, 1 << order
);
636 __free_one_page(page
, zone
, order
, migratetype
);
637 spin_unlock(&zone
->lock
);
640 static bool free_pages_prepare(struct page
*page
, unsigned int order
)
645 trace_mm_page_free_direct(page
, order
);
646 kmemcheck_free_shadow(page
, order
);
648 for (i
= 0; i
< (1 << order
); i
++) {
649 struct page
*pg
= page
+ i
;
653 bad
+= free_pages_check(pg
);
658 if (!PageHighMem(page
)) {
659 debug_check_no_locks_freed(page_address(page
),PAGE_SIZE
<<order
);
660 debug_check_no_obj_freed(page_address(page
),
663 arch_free_page(page
, order
);
664 kernel_map_pages(page
, 1 << order
, 0);
669 static void __free_pages_ok(struct page
*page
, unsigned int order
)
672 int wasMlocked
= __TestClearPageMlocked(page
);
674 if (!free_pages_prepare(page
, order
))
677 local_irq_save(flags
);
678 if (unlikely(wasMlocked
))
679 free_page_mlock(page
);
680 __count_vm_events(PGFREE
, 1 << order
);
681 free_one_page(page_zone(page
), page
, order
,
682 get_pageblock_migratetype(page
));
683 local_irq_restore(flags
);
687 * permit the bootmem allocator to evade page validation on high-order frees
689 void __meminit
__free_pages_bootmem(struct page
*page
, unsigned int order
)
692 __ClearPageReserved(page
);
693 set_page_count(page
, 0);
694 set_page_refcounted(page
);
700 for (loop
= 0; loop
< BITS_PER_LONG
; loop
++) {
701 struct page
*p
= &page
[loop
];
703 if (loop
+ 1 < BITS_PER_LONG
)
705 __ClearPageReserved(p
);
706 set_page_count(p
, 0);
709 set_page_refcounted(page
);
710 __free_pages(page
, order
);
716 * The order of subdivision here is critical for the IO subsystem.
717 * Please do not alter this order without good reasons and regression
718 * testing. Specifically, as large blocks of memory are subdivided,
719 * the order in which smaller blocks are delivered depends on the order
720 * they're subdivided in this function. This is the primary factor
721 * influencing the order in which pages are delivered to the IO
722 * subsystem according to empirical testing, and this is also justified
723 * by considering the behavior of a buddy system containing a single
724 * large block of memory acted on by a series of small allocations.
725 * This behavior is a critical factor in sglist merging's success.
729 static inline void expand(struct zone
*zone
, struct page
*page
,
730 int low
, int high
, struct free_area
*area
,
733 unsigned long size
= 1 << high
;
739 VM_BUG_ON(bad_range(zone
, &page
[size
]));
740 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
742 set_page_order(&page
[size
], high
);
747 * This page is about to be returned from the page allocator
749 static inline int check_new_page(struct page
*page
)
751 if (unlikely(page_mapcount(page
) |
752 (page
->mapping
!= NULL
) |
753 (atomic_read(&page
->_count
) != 0) |
754 (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
))) {
761 static int prep_new_page(struct page
*page
, int order
, gfp_t gfp_flags
)
765 for (i
= 0; i
< (1 << order
); i
++) {
766 struct page
*p
= page
+ i
;
767 if (unlikely(check_new_page(p
)))
771 set_page_private(page
, 0);
772 set_page_refcounted(page
);
774 arch_alloc_page(page
, order
);
775 kernel_map_pages(page
, 1 << order
, 1);
777 if (gfp_flags
& __GFP_ZERO
)
778 prep_zero_page(page
, order
, gfp_flags
);
780 if (order
&& (gfp_flags
& __GFP_COMP
))
781 prep_compound_page(page
, order
);
787 * Go through the free lists for the given migratetype and remove
788 * the smallest available page from the freelists
791 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
794 unsigned int current_order
;
795 struct free_area
* area
;
798 /* Find a page of the appropriate size in the preferred list */
799 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
800 area
= &(zone
->free_area
[current_order
]);
801 if (list_empty(&area
->free_list
[migratetype
]))
804 page
= list_entry(area
->free_list
[migratetype
].next
,
806 list_del(&page
->lru
);
807 rmv_page_order(page
);
809 expand(zone
, page
, order
, current_order
, area
, migratetype
);
818 * This array describes the order lists are fallen back to when
819 * the free lists for the desirable migrate type are depleted
821 static int fallbacks
[MIGRATE_TYPES
][MIGRATE_TYPES
-1] = {
822 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
823 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
824 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
825 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
, MIGRATE_RESERVE
, MIGRATE_RESERVE
}, /* Never used */
829 * Move the free pages in a range to the free lists of the requested type.
830 * Note that start_page and end_pages are not aligned on a pageblock
831 * boundary. If alignment is required, use move_freepages_block()
833 static int move_freepages(struct zone
*zone
,
834 struct page
*start_page
, struct page
*end_page
,
841 #ifndef CONFIG_HOLES_IN_ZONE
843 * page_zone is not safe to call in this context when
844 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
845 * anyway as we check zone boundaries in move_freepages_block().
846 * Remove at a later date when no bug reports exist related to
847 * grouping pages by mobility
849 BUG_ON(page_zone(start_page
) != page_zone(end_page
));
852 for (page
= start_page
; page
<= end_page
;) {
853 /* Make sure we are not inadvertently changing nodes */
854 VM_BUG_ON(page_to_nid(page
) != zone_to_nid(zone
));
856 if (!pfn_valid_within(page_to_pfn(page
))) {
861 if (!PageBuddy(page
)) {
866 order
= page_order(page
);
867 list_del(&page
->lru
);
869 &zone
->free_area
[order
].free_list
[migratetype
]);
871 pages_moved
+= 1 << order
;
877 static int move_freepages_block(struct zone
*zone
, struct page
*page
,
880 unsigned long start_pfn
, end_pfn
;
881 struct page
*start_page
, *end_page
;
883 start_pfn
= page_to_pfn(page
);
884 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
885 start_page
= pfn_to_page(start_pfn
);
886 end_page
= start_page
+ pageblock_nr_pages
- 1;
887 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
889 /* Do not cross zone boundaries */
890 if (start_pfn
< zone
->zone_start_pfn
)
892 if (end_pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
895 return move_freepages(zone
, start_page
, end_page
, migratetype
);
898 static void change_pageblock_range(struct page
*pageblock_page
,
899 int start_order
, int migratetype
)
901 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
903 while (nr_pageblocks
--) {
904 set_pageblock_migratetype(pageblock_page
, migratetype
);
905 pageblock_page
+= pageblock_nr_pages
;
909 /* Remove an element from the buddy allocator from the fallback list */
910 static inline struct page
*
911 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
)
913 struct free_area
* area
;
918 /* Find the largest possible block of pages in the other list */
919 for (current_order
= MAX_ORDER
-1; current_order
>= order
;
921 for (i
= 0; i
< MIGRATE_TYPES
- 1; i
++) {
922 migratetype
= fallbacks
[start_migratetype
][i
];
924 /* MIGRATE_RESERVE handled later if necessary */
925 if (migratetype
== MIGRATE_RESERVE
)
928 area
= &(zone
->free_area
[current_order
]);
929 if (list_empty(&area
->free_list
[migratetype
]))
932 page
= list_entry(area
->free_list
[migratetype
].next
,
937 * If breaking a large block of pages, move all free
938 * pages to the preferred allocation list. If falling
939 * back for a reclaimable kernel allocation, be more
940 * agressive about taking ownership of free pages
942 if (unlikely(current_order
>= (pageblock_order
>> 1)) ||
943 start_migratetype
== MIGRATE_RECLAIMABLE
||
944 page_group_by_mobility_disabled
) {
946 pages
= move_freepages_block(zone
, page
,
949 /* Claim the whole block if over half of it is free */
950 if (pages
>= (1 << (pageblock_order
-1)) ||
951 page_group_by_mobility_disabled
)
952 set_pageblock_migratetype(page
,
955 migratetype
= start_migratetype
;
958 /* Remove the page from the freelists */
959 list_del(&page
->lru
);
960 rmv_page_order(page
);
962 /* Take ownership for orders >= pageblock_order */
963 if (current_order
>= pageblock_order
)
964 change_pageblock_range(page
, current_order
,
967 expand(zone
, page
, order
, current_order
, area
, migratetype
);
969 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
970 start_migratetype
, migratetype
);
980 * Do the hard work of removing an element from the buddy allocator.
981 * Call me with the zone->lock already held.
983 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
989 page
= __rmqueue_smallest(zone
, order
, migratetype
);
991 if (unlikely(!page
) && migratetype
!= MIGRATE_RESERVE
) {
992 page
= __rmqueue_fallback(zone
, order
, migratetype
);
995 * Use MIGRATE_RESERVE rather than fail an allocation. goto
996 * is used because __rmqueue_smallest is an inline function
997 * and we want just one call site
1000 migratetype
= MIGRATE_RESERVE
;
1005 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
1010 * Obtain a specified number of elements from the buddy allocator, all under
1011 * a single hold of the lock, for efficiency. Add them to the supplied list.
1012 * Returns the number of new pages which were placed at *list.
1014 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
1015 unsigned long count
, struct list_head
*list
,
1016 int migratetype
, int cold
)
1020 spin_lock(&zone
->lock
);
1021 for (i
= 0; i
< count
; ++i
) {
1022 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
1023 if (unlikely(page
== NULL
))
1027 * Split buddy pages returned by expand() are received here
1028 * in physical page order. The page is added to the callers and
1029 * list and the list head then moves forward. From the callers
1030 * perspective, the linked list is ordered by page number in
1031 * some conditions. This is useful for IO devices that can
1032 * merge IO requests if the physical pages are ordered
1035 if (likely(cold
== 0))
1036 list_add(&page
->lru
, list
);
1038 list_add_tail(&page
->lru
, list
);
1039 set_page_private(page
, migratetype
);
1042 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
1043 spin_unlock(&zone
->lock
);
1049 * Called from the vmstat counter updater to drain pagesets of this
1050 * currently executing processor on remote nodes after they have
1053 * Note that this function must be called with the thread pinned to
1054 * a single processor.
1056 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
1058 unsigned long flags
;
1061 local_irq_save(flags
);
1062 if (pcp
->count
>= pcp
->batch
)
1063 to_drain
= pcp
->batch
;
1065 to_drain
= pcp
->count
;
1066 free_pcppages_bulk(zone
, to_drain
, pcp
);
1067 pcp
->count
-= to_drain
;
1068 local_irq_restore(flags
);
1073 * Drain pages of the indicated processor.
1075 * The processor must either be the current processor and the
1076 * thread pinned to the current processor or a processor that
1079 static void drain_pages(unsigned int cpu
)
1081 unsigned long flags
;
1084 for_each_populated_zone(zone
) {
1085 struct per_cpu_pageset
*pset
;
1086 struct per_cpu_pages
*pcp
;
1088 local_irq_save(flags
);
1089 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
1092 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
1094 local_irq_restore(flags
);
1099 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1101 void drain_local_pages(void *arg
)
1103 drain_pages(smp_processor_id());
1107 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
1109 void drain_all_pages(void)
1111 on_each_cpu(drain_local_pages
, NULL
, 1);
1114 #ifdef CONFIG_HIBERNATION
1116 void mark_free_pages(struct zone
*zone
)
1118 unsigned long pfn
, max_zone_pfn
;
1119 unsigned long flags
;
1121 struct list_head
*curr
;
1123 if (!zone
->spanned_pages
)
1126 spin_lock_irqsave(&zone
->lock
, flags
);
1128 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
1129 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1130 if (pfn_valid(pfn
)) {
1131 struct page
*page
= pfn_to_page(pfn
);
1133 if (!swsusp_page_is_forbidden(page
))
1134 swsusp_unset_page_free(page
);
1137 for_each_migratetype_order(order
, t
) {
1138 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
1141 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
1142 for (i
= 0; i
< (1UL << order
); i
++)
1143 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
1146 spin_unlock_irqrestore(&zone
->lock
, flags
);
1148 #endif /* CONFIG_PM */
1151 * Free a 0-order page
1152 * cold == 1 ? free a cold page : free a hot page
1154 void free_hot_cold_page(struct page
*page
, int cold
)
1156 struct zone
*zone
= page_zone(page
);
1157 struct per_cpu_pages
*pcp
;
1158 unsigned long flags
;
1160 int wasMlocked
= __TestClearPageMlocked(page
);
1162 if (!free_pages_prepare(page
, 0))
1165 migratetype
= get_pageblock_migratetype(page
);
1166 set_page_private(page
, migratetype
);
1167 local_irq_save(flags
);
1168 if (unlikely(wasMlocked
))
1169 free_page_mlock(page
);
1170 __count_vm_event(PGFREE
);
1173 * We only track unmovable, reclaimable and movable on pcp lists.
1174 * Free ISOLATE pages back to the allocator because they are being
1175 * offlined but treat RESERVE as movable pages so we can get those
1176 * areas back if necessary. Otherwise, we may have to free
1177 * excessively into the page allocator
1179 if (migratetype
>= MIGRATE_PCPTYPES
) {
1180 if (unlikely(migratetype
== MIGRATE_ISOLATE
)) {
1181 free_one_page(zone
, page
, 0, migratetype
);
1184 migratetype
= MIGRATE_MOVABLE
;
1187 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1189 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
1191 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
1193 if (pcp
->count
>= pcp
->high
) {
1194 free_pcppages_bulk(zone
, pcp
->batch
, pcp
);
1195 pcp
->count
-= pcp
->batch
;
1199 local_irq_restore(flags
);
1203 * split_page takes a non-compound higher-order page, and splits it into
1204 * n (1<<order) sub-pages: page[0..n]
1205 * Each sub-page must be freed individually.
1207 * Note: this is probably too low level an operation for use in drivers.
1208 * Please consult with lkml before using this in your driver.
1210 void split_page(struct page
*page
, unsigned int order
)
1214 VM_BUG_ON(PageCompound(page
));
1215 VM_BUG_ON(!page_count(page
));
1217 #ifdef CONFIG_KMEMCHECK
1219 * Split shadow pages too, because free(page[0]) would
1220 * otherwise free the whole shadow.
1222 if (kmemcheck_page_is_tracked(page
))
1223 split_page(virt_to_page(page
[0].shadow
), order
);
1226 for (i
= 1; i
< (1 << order
); i
++)
1227 set_page_refcounted(page
+ i
);
1231 * Similar to split_page except the page is already free. As this is only
1232 * being used for migration, the migratetype of the block also changes.
1233 * As this is called with interrupts disabled, the caller is responsible
1234 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1237 * Note: this is probably too low level an operation for use in drivers.
1238 * Please consult with lkml before using this in your driver.
1240 int split_free_page(struct page
*page
)
1243 unsigned long watermark
;
1246 BUG_ON(!PageBuddy(page
));
1248 zone
= page_zone(page
);
1249 order
= page_order(page
);
1251 /* Obey watermarks as if the page was being allocated */
1252 watermark
= low_wmark_pages(zone
) + (1 << order
);
1253 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
1256 /* Remove page from free list */
1257 list_del(&page
->lru
);
1258 zone
->free_area
[order
].nr_free
--;
1259 rmv_page_order(page
);
1260 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(1UL << order
));
1262 /* Split into individual pages */
1263 set_page_refcounted(page
);
1264 split_page(page
, order
);
1266 if (order
>= pageblock_order
- 1) {
1267 struct page
*endpage
= page
+ (1 << order
) - 1;
1268 for (; page
< endpage
; page
+= pageblock_nr_pages
)
1269 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1276 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1277 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1281 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
1282 struct zone
*zone
, int order
, gfp_t gfp_flags
,
1285 unsigned long flags
;
1287 int cold
= !!(gfp_flags
& __GFP_COLD
);
1290 if (likely(order
== 0)) {
1291 struct per_cpu_pages
*pcp
;
1292 struct list_head
*list
;
1294 local_irq_save(flags
);
1295 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1296 list
= &pcp
->lists
[migratetype
];
1297 if (list_empty(list
)) {
1298 pcp
->count
+= rmqueue_bulk(zone
, 0,
1301 if (unlikely(list_empty(list
)))
1306 page
= list_entry(list
->prev
, struct page
, lru
);
1308 page
= list_entry(list
->next
, struct page
, lru
);
1310 list_del(&page
->lru
);
1313 if (unlikely(gfp_flags
& __GFP_NOFAIL
)) {
1315 * __GFP_NOFAIL is not to be used in new code.
1317 * All __GFP_NOFAIL callers should be fixed so that they
1318 * properly detect and handle allocation failures.
1320 * We most definitely don't want callers attempting to
1321 * allocate greater than order-1 page units with
1324 WARN_ON_ONCE(order
> 1);
1326 spin_lock_irqsave(&zone
->lock
, flags
);
1327 page
= __rmqueue(zone
, order
, migratetype
);
1328 spin_unlock(&zone
->lock
);
1331 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(1 << order
));
1334 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
1335 zone_statistics(preferred_zone
, zone
);
1336 local_irq_restore(flags
);
1338 VM_BUG_ON(bad_range(zone
, page
));
1339 if (prep_new_page(page
, order
, gfp_flags
))
1344 local_irq_restore(flags
);
1348 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
1349 #define ALLOC_WMARK_MIN WMARK_MIN
1350 #define ALLOC_WMARK_LOW WMARK_LOW
1351 #define ALLOC_WMARK_HIGH WMARK_HIGH
1352 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
1354 /* Mask to get the watermark bits */
1355 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
1357 #define ALLOC_HARDER 0x10 /* try to alloc harder */
1358 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
1359 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
1361 #ifdef CONFIG_FAIL_PAGE_ALLOC
1363 static struct fail_page_alloc_attr
{
1364 struct fault_attr attr
;
1366 u32 ignore_gfp_highmem
;
1367 u32 ignore_gfp_wait
;
1370 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1372 struct dentry
*ignore_gfp_highmem_file
;
1373 struct dentry
*ignore_gfp_wait_file
;
1374 struct dentry
*min_order_file
;
1376 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1378 } fail_page_alloc
= {
1379 .attr
= FAULT_ATTR_INITIALIZER
,
1380 .ignore_gfp_wait
= 1,
1381 .ignore_gfp_highmem
= 1,
1385 static int __init
setup_fail_page_alloc(char *str
)
1387 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
1389 __setup("fail_page_alloc=", setup_fail_page_alloc
);
1391 static int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1393 if (order
< fail_page_alloc
.min_order
)
1395 if (gfp_mask
& __GFP_NOFAIL
)
1397 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
1399 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
1402 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
1405 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1407 static int __init
fail_page_alloc_debugfs(void)
1409 mode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
1413 err
= init_fault_attr_dentries(&fail_page_alloc
.attr
,
1417 dir
= fail_page_alloc
.attr
.dentries
.dir
;
1419 fail_page_alloc
.ignore_gfp_wait_file
=
1420 debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
1421 &fail_page_alloc
.ignore_gfp_wait
);
1423 fail_page_alloc
.ignore_gfp_highmem_file
=
1424 debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
1425 &fail_page_alloc
.ignore_gfp_highmem
);
1426 fail_page_alloc
.min_order_file
=
1427 debugfs_create_u32("min-order", mode
, dir
,
1428 &fail_page_alloc
.min_order
);
1430 if (!fail_page_alloc
.ignore_gfp_wait_file
||
1431 !fail_page_alloc
.ignore_gfp_highmem_file
||
1432 !fail_page_alloc
.min_order_file
) {
1434 debugfs_remove(fail_page_alloc
.ignore_gfp_wait_file
);
1435 debugfs_remove(fail_page_alloc
.ignore_gfp_highmem_file
);
1436 debugfs_remove(fail_page_alloc
.min_order_file
);
1437 cleanup_fault_attr_dentries(&fail_page_alloc
.attr
);
1443 late_initcall(fail_page_alloc_debugfs
);
1445 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1447 #else /* CONFIG_FAIL_PAGE_ALLOC */
1449 static inline int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1454 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1457 * Return 1 if free pages are above 'mark'. This takes into account the order
1458 * of the allocation.
1460 int zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1461 int classzone_idx
, int alloc_flags
)
1463 /* free_pages my go negative - that's OK */
1465 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
) - (1 << order
) + 1;
1468 if (alloc_flags
& ALLOC_HIGH
)
1470 if (alloc_flags
& ALLOC_HARDER
)
1473 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
1475 for (o
= 0; o
< order
; o
++) {
1476 /* At the next order, this order's pages become unavailable */
1477 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
1479 /* Require fewer higher order pages to be free */
1482 if (free_pages
<= min
)
1490 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1491 * skip over zones that are not allowed by the cpuset, or that have
1492 * been recently (in last second) found to be nearly full. See further
1493 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1494 * that have to skip over a lot of full or unallowed zones.
1496 * If the zonelist cache is present in the passed in zonelist, then
1497 * returns a pointer to the allowed node mask (either the current
1498 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1500 * If the zonelist cache is not available for this zonelist, does
1501 * nothing and returns NULL.
1503 * If the fullzones BITMAP in the zonelist cache is stale (more than
1504 * a second since last zap'd) then we zap it out (clear its bits.)
1506 * We hold off even calling zlc_setup, until after we've checked the
1507 * first zone in the zonelist, on the theory that most allocations will
1508 * be satisfied from that first zone, so best to examine that zone as
1509 * quickly as we can.
1511 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1513 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1514 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
1516 zlc
= zonelist
->zlcache_ptr
;
1520 if (time_after(jiffies
, zlc
->last_full_zap
+ HZ
)) {
1521 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1522 zlc
->last_full_zap
= jiffies
;
1525 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
1526 &cpuset_current_mems_allowed
:
1527 &node_states
[N_HIGH_MEMORY
];
1528 return allowednodes
;
1532 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1533 * if it is worth looking at further for free memory:
1534 * 1) Check that the zone isn't thought to be full (doesn't have its
1535 * bit set in the zonelist_cache fullzones BITMAP).
1536 * 2) Check that the zones node (obtained from the zonelist_cache
1537 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1538 * Return true (non-zero) if zone is worth looking at further, or
1539 * else return false (zero) if it is not.
1541 * This check -ignores- the distinction between various watermarks,
1542 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1543 * found to be full for any variation of these watermarks, it will
1544 * be considered full for up to one second by all requests, unless
1545 * we are so low on memory on all allowed nodes that we are forced
1546 * into the second scan of the zonelist.
1548 * In the second scan we ignore this zonelist cache and exactly
1549 * apply the watermarks to all zones, even it is slower to do so.
1550 * We are low on memory in the second scan, and should leave no stone
1551 * unturned looking for a free page.
1553 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1554 nodemask_t
*allowednodes
)
1556 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1557 int i
; /* index of *z in zonelist zones */
1558 int n
; /* node that zone *z is on */
1560 zlc
= zonelist
->zlcache_ptr
;
1564 i
= z
- zonelist
->_zonerefs
;
1567 /* This zone is worth trying if it is allowed but not full */
1568 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1572 * Given 'z' scanning a zonelist, set the corresponding bit in
1573 * zlc->fullzones, so that subsequent attempts to allocate a page
1574 * from that zone don't waste time re-examining it.
1576 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1578 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1579 int i
; /* index of *z in zonelist zones */
1581 zlc
= zonelist
->zlcache_ptr
;
1585 i
= z
- zonelist
->_zonerefs
;
1587 set_bit(i
, zlc
->fullzones
);
1590 #else /* CONFIG_NUMA */
1592 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1597 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1598 nodemask_t
*allowednodes
)
1603 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1606 #endif /* CONFIG_NUMA */
1609 * get_page_from_freelist goes through the zonelist trying to allocate
1612 static struct page
*
1613 get_page_from_freelist(gfp_t gfp_mask
, nodemask_t
*nodemask
, unsigned int order
,
1614 struct zonelist
*zonelist
, int high_zoneidx
, int alloc_flags
,
1615 struct zone
*preferred_zone
, int migratetype
)
1618 struct page
*page
= NULL
;
1621 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
1622 int zlc_active
= 0; /* set if using zonelist_cache */
1623 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
1625 classzone_idx
= zone_idx(preferred_zone
);
1628 * Scan zonelist, looking for a zone with enough free.
1629 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1631 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
1632 high_zoneidx
, nodemask
) {
1633 if (NUMA_BUILD
&& zlc_active
&&
1634 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1636 if ((alloc_flags
& ALLOC_CPUSET
) &&
1637 !cpuset_zone_allowed_softwall(zone
, gfp_mask
))
1640 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
1641 if (!(alloc_flags
& ALLOC_NO_WATERMARKS
)) {
1645 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
1646 if (zone_watermark_ok(zone
, order
, mark
,
1647 classzone_idx
, alloc_flags
))
1650 if (zone_reclaim_mode
== 0)
1651 goto this_zone_full
;
1653 ret
= zone_reclaim(zone
, gfp_mask
, order
);
1655 case ZONE_RECLAIM_NOSCAN
:
1658 case ZONE_RECLAIM_FULL
:
1659 /* scanned but unreclaimable */
1660 goto this_zone_full
;
1662 /* did we reclaim enough */
1663 if (!zone_watermark_ok(zone
, order
, mark
,
1664 classzone_idx
, alloc_flags
))
1665 goto this_zone_full
;
1670 page
= buffered_rmqueue(preferred_zone
, zone
, order
,
1671 gfp_mask
, migratetype
);
1676 zlc_mark_zone_full(zonelist
, z
);
1678 if (NUMA_BUILD
&& !did_zlc_setup
&& nr_online_nodes
> 1) {
1680 * we do zlc_setup after the first zone is tried but only
1681 * if there are multiple nodes make it worthwhile
1683 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
1689 if (unlikely(NUMA_BUILD
&& page
== NULL
&& zlc_active
)) {
1690 /* Disable zlc cache for second zonelist scan */
1698 should_alloc_retry(gfp_t gfp_mask
, unsigned int order
,
1699 unsigned long pages_reclaimed
)
1701 /* Do not loop if specifically requested */
1702 if (gfp_mask
& __GFP_NORETRY
)
1706 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
1707 * means __GFP_NOFAIL, but that may not be true in other
1710 if (order
<= PAGE_ALLOC_COSTLY_ORDER
)
1714 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
1715 * specified, then we retry until we no longer reclaim any pages
1716 * (above), or we've reclaimed an order of pages at least as
1717 * large as the allocation's order. In both cases, if the
1718 * allocation still fails, we stop retrying.
1720 if (gfp_mask
& __GFP_REPEAT
&& pages_reclaimed
< (1 << order
))
1724 * Don't let big-order allocations loop unless the caller
1725 * explicitly requests that.
1727 if (gfp_mask
& __GFP_NOFAIL
)
1733 static inline struct page
*
1734 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
1735 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1736 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
1741 /* Acquire the OOM killer lock for the zones in zonelist */
1742 if (!try_set_zonelist_oom(zonelist
, gfp_mask
)) {
1743 schedule_timeout_uninterruptible(1);
1748 * Go through the zonelist yet one more time, keep very high watermark
1749 * here, this is only to catch a parallel oom killing, we must fail if
1750 * we're still under heavy pressure.
1752 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
,
1753 order
, zonelist
, high_zoneidx
,
1754 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
,
1755 preferred_zone
, migratetype
);
1759 if (!(gfp_mask
& __GFP_NOFAIL
)) {
1760 /* The OOM killer will not help higher order allocs */
1761 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
1763 /* The OOM killer does not needlessly kill tasks for lowmem */
1764 if (high_zoneidx
< ZONE_NORMAL
)
1767 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
1768 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
1769 * The caller should handle page allocation failure by itself if
1770 * it specifies __GFP_THISNODE.
1771 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
1773 if (gfp_mask
& __GFP_THISNODE
)
1776 /* Exhausted what can be done so it's blamo time */
1777 out_of_memory(zonelist
, gfp_mask
, order
, nodemask
);
1780 clear_zonelist_oom(zonelist
, gfp_mask
);
1784 #ifdef CONFIG_COMPACTION
1785 /* Try memory compaction for high-order allocations before reclaim */
1786 static struct page
*
1787 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
1788 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1789 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
1790 int migratetype
, unsigned long *did_some_progress
)
1794 if (!order
|| compaction_deferred(preferred_zone
))
1797 *did_some_progress
= try_to_compact_pages(zonelist
, order
, gfp_mask
,
1799 if (*did_some_progress
!= COMPACT_SKIPPED
) {
1801 /* Page migration frees to the PCP lists but we want merging */
1802 drain_pages(get_cpu());
1805 page
= get_page_from_freelist(gfp_mask
, nodemask
,
1806 order
, zonelist
, high_zoneidx
,
1807 alloc_flags
, preferred_zone
,
1810 preferred_zone
->compact_considered
= 0;
1811 preferred_zone
->compact_defer_shift
= 0;
1812 count_vm_event(COMPACTSUCCESS
);
1817 * It's bad if compaction run occurs and fails.
1818 * The most likely reason is that pages exist,
1819 * but not enough to satisfy watermarks.
1821 count_vm_event(COMPACTFAIL
);
1822 defer_compaction(preferred_zone
);
1830 static inline struct page
*
1831 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
1832 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1833 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
1834 int migratetype
, unsigned long *did_some_progress
)
1838 #endif /* CONFIG_COMPACTION */
1840 /* The really slow allocator path where we enter direct reclaim */
1841 static inline struct page
*
1842 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
1843 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1844 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
1845 int migratetype
, unsigned long *did_some_progress
)
1847 struct page
*page
= NULL
;
1848 struct reclaim_state reclaim_state
;
1849 struct task_struct
*p
= current
;
1853 /* We now go into synchronous reclaim */
1854 cpuset_memory_pressure_bump();
1855 p
->flags
|= PF_MEMALLOC
;
1856 lockdep_set_current_reclaim_state(gfp_mask
);
1857 reclaim_state
.reclaimed_slab
= 0;
1858 p
->reclaim_state
= &reclaim_state
;
1860 *did_some_progress
= try_to_free_pages(zonelist
, order
, gfp_mask
, nodemask
);
1862 p
->reclaim_state
= NULL
;
1863 lockdep_clear_current_reclaim_state();
1864 p
->flags
&= ~PF_MEMALLOC
;
1871 if (likely(*did_some_progress
))
1872 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
1873 zonelist
, high_zoneidx
,
1874 alloc_flags
, preferred_zone
,
1880 * This is called in the allocator slow-path if the allocation request is of
1881 * sufficient urgency to ignore watermarks and take other desperate measures
1883 static inline struct page
*
1884 __alloc_pages_high_priority(gfp_t gfp_mask
, unsigned int order
,
1885 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1886 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
1892 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
1893 zonelist
, high_zoneidx
, ALLOC_NO_WATERMARKS
,
1894 preferred_zone
, migratetype
);
1896 if (!page
&& gfp_mask
& __GFP_NOFAIL
)
1897 congestion_wait(BLK_RW_ASYNC
, HZ
/50);
1898 } while (!page
&& (gfp_mask
& __GFP_NOFAIL
));
1904 void wake_all_kswapd(unsigned int order
, struct zonelist
*zonelist
,
1905 enum zone_type high_zoneidx
)
1910 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
)
1911 wakeup_kswapd(zone
, order
);
1915 gfp_to_alloc_flags(gfp_t gfp_mask
)
1917 struct task_struct
*p
= current
;
1918 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
1919 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
1921 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
1922 BUILD_BUG_ON(__GFP_HIGH
!= ALLOC_HIGH
);
1925 * The caller may dip into page reserves a bit more if the caller
1926 * cannot run direct reclaim, or if the caller has realtime scheduling
1927 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
1928 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1930 alloc_flags
|= (gfp_mask
& __GFP_HIGH
);
1933 alloc_flags
|= ALLOC_HARDER
;
1935 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1936 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1938 alloc_flags
&= ~ALLOC_CPUSET
;
1939 } else if (unlikely(rt_task(p
)) && !in_interrupt())
1940 alloc_flags
|= ALLOC_HARDER
;
1942 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
1943 if (!in_interrupt() &&
1944 ((p
->flags
& PF_MEMALLOC
) ||
1945 unlikely(test_thread_flag(TIF_MEMDIE
))))
1946 alloc_flags
|= ALLOC_NO_WATERMARKS
;
1952 static inline struct page
*
1953 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
1954 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1955 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
1958 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
1959 struct page
*page
= NULL
;
1961 unsigned long pages_reclaimed
= 0;
1962 unsigned long did_some_progress
;
1963 struct task_struct
*p
= current
;
1966 * In the slowpath, we sanity check order to avoid ever trying to
1967 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
1968 * be using allocators in order of preference for an area that is
1971 if (order
>= MAX_ORDER
) {
1972 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
1977 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
1978 * __GFP_NOWARN set) should not cause reclaim since the subsystem
1979 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
1980 * using a larger set of nodes after it has established that the
1981 * allowed per node queues are empty and that nodes are
1984 if (NUMA_BUILD
&& (gfp_mask
& GFP_THISNODE
) == GFP_THISNODE
)
1988 wake_all_kswapd(order
, zonelist
, high_zoneidx
);
1991 * OK, we're below the kswapd watermark and have kicked background
1992 * reclaim. Now things get more complex, so set up alloc_flags according
1993 * to how we want to proceed.
1995 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
1997 /* This is the last chance, in general, before the goto nopage. */
1998 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
, zonelist
,
1999 high_zoneidx
, alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2000 preferred_zone
, migratetype
);
2005 /* Allocate without watermarks if the context allows */
2006 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
2007 page
= __alloc_pages_high_priority(gfp_mask
, order
,
2008 zonelist
, high_zoneidx
, nodemask
,
2009 preferred_zone
, migratetype
);
2014 /* Atomic allocations - we can't balance anything */
2018 /* Avoid recursion of direct reclaim */
2019 if (p
->flags
& PF_MEMALLOC
)
2022 /* Avoid allocations with no watermarks from looping endlessly */
2023 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
2026 /* Try direct compaction */
2027 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
2028 zonelist
, high_zoneidx
,
2030 alloc_flags
, preferred_zone
,
2031 migratetype
, &did_some_progress
);
2035 /* Try direct reclaim and then allocating */
2036 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
,
2037 zonelist
, high_zoneidx
,
2039 alloc_flags
, preferred_zone
,
2040 migratetype
, &did_some_progress
);
2045 * If we failed to make any progress reclaiming, then we are
2046 * running out of options and have to consider going OOM
2048 if (!did_some_progress
) {
2049 if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
2050 if (oom_killer_disabled
)
2052 page
= __alloc_pages_may_oom(gfp_mask
, order
,
2053 zonelist
, high_zoneidx
,
2054 nodemask
, preferred_zone
,
2059 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2061 * The oom killer is not called for high-order
2062 * allocations that may fail, so if no progress
2063 * is being made, there are no other options and
2064 * retrying is unlikely to help.
2066 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2069 * The oom killer is not called for lowmem
2070 * allocations to prevent needlessly killing
2073 if (high_zoneidx
< ZONE_NORMAL
)
2081 /* Check if we should retry the allocation */
2082 pages_reclaimed
+= did_some_progress
;
2083 if (should_alloc_retry(gfp_mask
, order
, pages_reclaimed
)) {
2084 /* Wait for some write requests to complete then retry */
2085 congestion_wait(BLK_RW_ASYNC
, HZ
/50);
2090 if (!(gfp_mask
& __GFP_NOWARN
) && printk_ratelimit()) {
2091 printk(KERN_WARNING
"%s: page allocation failure."
2092 " order:%d, mode:0x%x\n",
2093 p
->comm
, order
, gfp_mask
);
2099 if (kmemcheck_enabled
)
2100 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
2106 * This is the 'heart' of the zoned buddy allocator.
2109 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
2110 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
2112 enum zone_type high_zoneidx
= gfp_zone(gfp_mask
);
2113 struct zone
*preferred_zone
;
2115 int migratetype
= allocflags_to_migratetype(gfp_mask
);
2117 gfp_mask
&= gfp_allowed_mask
;
2119 lockdep_trace_alloc(gfp_mask
);
2121 might_sleep_if(gfp_mask
& __GFP_WAIT
);
2123 if (should_fail_alloc_page(gfp_mask
, order
))
2127 * Check the zones suitable for the gfp_mask contain at least one
2128 * valid zone. It's possible to have an empty zonelist as a result
2129 * of GFP_THISNODE and a memoryless node
2131 if (unlikely(!zonelist
->_zonerefs
->zone
))
2135 /* The preferred zone is used for statistics later */
2136 first_zones_zonelist(zonelist
, high_zoneidx
, nodemask
, &preferred_zone
);
2137 if (!preferred_zone
) {
2142 /* First allocation attempt */
2143 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
, order
,
2144 zonelist
, high_zoneidx
, ALLOC_WMARK_LOW
|ALLOC_CPUSET
,
2145 preferred_zone
, migratetype
);
2146 if (unlikely(!page
))
2147 page
= __alloc_pages_slowpath(gfp_mask
, order
,
2148 zonelist
, high_zoneidx
, nodemask
,
2149 preferred_zone
, migratetype
);
2152 trace_mm_page_alloc(page
, order
, gfp_mask
, migratetype
);
2155 EXPORT_SYMBOL(__alloc_pages_nodemask
);
2158 * Common helper functions.
2160 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
2165 * __get_free_pages() returns a 32-bit address, which cannot represent
2168 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
2170 page
= alloc_pages(gfp_mask
, order
);
2173 return (unsigned long) page_address(page
);
2175 EXPORT_SYMBOL(__get_free_pages
);
2177 unsigned long get_zeroed_page(gfp_t gfp_mask
)
2179 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
2181 EXPORT_SYMBOL(get_zeroed_page
);
2183 void __pagevec_free(struct pagevec
*pvec
)
2185 int i
= pagevec_count(pvec
);
2188 trace_mm_pagevec_free(pvec
->pages
[i
], pvec
->cold
);
2189 free_hot_cold_page(pvec
->pages
[i
], pvec
->cold
);
2193 void __free_pages(struct page
*page
, unsigned int order
)
2195 if (put_page_testzero(page
)) {
2197 free_hot_cold_page(page
, 0);
2199 __free_pages_ok(page
, order
);
2203 EXPORT_SYMBOL(__free_pages
);
2205 void free_pages(unsigned long addr
, unsigned int order
)
2208 VM_BUG_ON(!virt_addr_valid((void *)addr
));
2209 __free_pages(virt_to_page((void *)addr
), order
);
2213 EXPORT_SYMBOL(free_pages
);
2216 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2217 * @size: the number of bytes to allocate
2218 * @gfp_mask: GFP flags for the allocation
2220 * This function is similar to alloc_pages(), except that it allocates the
2221 * minimum number of pages to satisfy the request. alloc_pages() can only
2222 * allocate memory in power-of-two pages.
2224 * This function is also limited by MAX_ORDER.
2226 * Memory allocated by this function must be released by free_pages_exact().
2228 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
2230 unsigned int order
= get_order(size
);
2233 addr
= __get_free_pages(gfp_mask
, order
);
2235 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
2236 unsigned long used
= addr
+ PAGE_ALIGN(size
);
2238 split_page(virt_to_page((void *)addr
), order
);
2239 while (used
< alloc_end
) {
2245 return (void *)addr
;
2247 EXPORT_SYMBOL(alloc_pages_exact
);
2250 * free_pages_exact - release memory allocated via alloc_pages_exact()
2251 * @virt: the value returned by alloc_pages_exact.
2252 * @size: size of allocation, same value as passed to alloc_pages_exact().
2254 * Release the memory allocated by a previous call to alloc_pages_exact.
2256 void free_pages_exact(void *virt
, size_t size
)
2258 unsigned long addr
= (unsigned long)virt
;
2259 unsigned long end
= addr
+ PAGE_ALIGN(size
);
2261 while (addr
< end
) {
2266 EXPORT_SYMBOL(free_pages_exact
);
2268 static unsigned int nr_free_zone_pages(int offset
)
2273 /* Just pick one node, since fallback list is circular */
2274 unsigned int sum
= 0;
2276 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
2278 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
2279 unsigned long size
= zone
->present_pages
;
2280 unsigned long high
= high_wmark_pages(zone
);
2289 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
2291 unsigned int nr_free_buffer_pages(void)
2293 return nr_free_zone_pages(gfp_zone(GFP_USER
));
2295 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
2298 * Amount of free RAM allocatable within all zones
2300 unsigned int nr_free_pagecache_pages(void)
2302 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
2305 static inline void show_node(struct zone
*zone
)
2308 printk("Node %d ", zone_to_nid(zone
));
2311 void si_meminfo(struct sysinfo
*val
)
2313 val
->totalram
= totalram_pages
;
2315 val
->freeram
= global_page_state(NR_FREE_PAGES
);
2316 val
->bufferram
= nr_blockdev_pages();
2317 val
->totalhigh
= totalhigh_pages
;
2318 val
->freehigh
= nr_free_highpages();
2319 val
->mem_unit
= PAGE_SIZE
;
2322 EXPORT_SYMBOL(si_meminfo
);
2325 void si_meminfo_node(struct sysinfo
*val
, int nid
)
2327 pg_data_t
*pgdat
= NODE_DATA(nid
);
2329 val
->totalram
= pgdat
->node_present_pages
;
2330 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
2331 #ifdef CONFIG_HIGHMEM
2332 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
2333 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
2339 val
->mem_unit
= PAGE_SIZE
;
2343 #define K(x) ((x) << (PAGE_SHIFT-10))
2346 * Show free area list (used inside shift_scroll-lock stuff)
2347 * We also calculate the percentage fragmentation. We do this by counting the
2348 * memory on each free list with the exception of the first item on the list.
2350 void show_free_areas(void)
2355 for_each_populated_zone(zone
) {
2357 printk("%s per-cpu:\n", zone
->name
);
2359 for_each_online_cpu(cpu
) {
2360 struct per_cpu_pageset
*pageset
;
2362 pageset
= per_cpu_ptr(zone
->pageset
, cpu
);
2364 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
2365 cpu
, pageset
->pcp
.high
,
2366 pageset
->pcp
.batch
, pageset
->pcp
.count
);
2370 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
2371 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
2373 " dirty:%lu writeback:%lu unstable:%lu\n"
2374 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2375 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
2376 global_page_state(NR_ACTIVE_ANON
),
2377 global_page_state(NR_INACTIVE_ANON
),
2378 global_page_state(NR_ISOLATED_ANON
),
2379 global_page_state(NR_ACTIVE_FILE
),
2380 global_page_state(NR_INACTIVE_FILE
),
2381 global_page_state(NR_ISOLATED_FILE
),
2382 global_page_state(NR_UNEVICTABLE
),
2383 global_page_state(NR_FILE_DIRTY
),
2384 global_page_state(NR_WRITEBACK
),
2385 global_page_state(NR_UNSTABLE_NFS
),
2386 global_page_state(NR_FREE_PAGES
),
2387 global_page_state(NR_SLAB_RECLAIMABLE
),
2388 global_page_state(NR_SLAB_UNRECLAIMABLE
),
2389 global_page_state(NR_FILE_MAPPED
),
2390 global_page_state(NR_SHMEM
),
2391 global_page_state(NR_PAGETABLE
),
2392 global_page_state(NR_BOUNCE
));
2394 for_each_populated_zone(zone
) {
2403 " active_anon:%lukB"
2404 " inactive_anon:%lukB"
2405 " active_file:%lukB"
2406 " inactive_file:%lukB"
2407 " unevictable:%lukB"
2408 " isolated(anon):%lukB"
2409 " isolated(file):%lukB"
2416 " slab_reclaimable:%lukB"
2417 " slab_unreclaimable:%lukB"
2418 " kernel_stack:%lukB"
2422 " writeback_tmp:%lukB"
2423 " pages_scanned:%lu"
2424 " all_unreclaimable? %s"
2427 K(zone_page_state(zone
, NR_FREE_PAGES
)),
2428 K(min_wmark_pages(zone
)),
2429 K(low_wmark_pages(zone
)),
2430 K(high_wmark_pages(zone
)),
2431 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
2432 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
2433 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
2434 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
2435 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
2436 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
2437 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
2438 K(zone
->present_pages
),
2439 K(zone_page_state(zone
, NR_MLOCK
)),
2440 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
2441 K(zone_page_state(zone
, NR_WRITEBACK
)),
2442 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
2443 K(zone_page_state(zone
, NR_SHMEM
)),
2444 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
2445 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
2446 zone_page_state(zone
, NR_KERNEL_STACK
) *
2448 K(zone_page_state(zone
, NR_PAGETABLE
)),
2449 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
2450 K(zone_page_state(zone
, NR_BOUNCE
)),
2451 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
2452 zone
->pages_scanned
,
2453 (zone
->all_unreclaimable
? "yes" : "no")
2455 printk("lowmem_reserve[]:");
2456 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
2457 printk(" %lu", zone
->lowmem_reserve
[i
]);
2461 for_each_populated_zone(zone
) {
2462 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
2465 printk("%s: ", zone
->name
);
2467 spin_lock_irqsave(&zone
->lock
, flags
);
2468 for (order
= 0; order
< MAX_ORDER
; order
++) {
2469 nr
[order
] = zone
->free_area
[order
].nr_free
;
2470 total
+= nr
[order
] << order
;
2472 spin_unlock_irqrestore(&zone
->lock
, flags
);
2473 for (order
= 0; order
< MAX_ORDER
; order
++)
2474 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
2475 printk("= %lukB\n", K(total
));
2478 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
2480 show_swap_cache_info();
2483 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
2485 zoneref
->zone
= zone
;
2486 zoneref
->zone_idx
= zone_idx(zone
);
2490 * Builds allocation fallback zone lists.
2492 * Add all populated zones of a node to the zonelist.
2494 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
2495 int nr_zones
, enum zone_type zone_type
)
2499 BUG_ON(zone_type
>= MAX_NR_ZONES
);
2504 zone
= pgdat
->node_zones
+ zone_type
;
2505 if (populated_zone(zone
)) {
2506 zoneref_set_zone(zone
,
2507 &zonelist
->_zonerefs
[nr_zones
++]);
2508 check_highest_zone(zone_type
);
2511 } while (zone_type
);
2518 * 0 = automatic detection of better ordering.
2519 * 1 = order by ([node] distance, -zonetype)
2520 * 2 = order by (-zonetype, [node] distance)
2522 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
2523 * the same zonelist. So only NUMA can configure this param.
2525 #define ZONELIST_ORDER_DEFAULT 0
2526 #define ZONELIST_ORDER_NODE 1
2527 #define ZONELIST_ORDER_ZONE 2
2529 /* zonelist order in the kernel.
2530 * set_zonelist_order() will set this to NODE or ZONE.
2532 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2533 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
2537 /* The value user specified ....changed by config */
2538 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2539 /* string for sysctl */
2540 #define NUMA_ZONELIST_ORDER_LEN 16
2541 char numa_zonelist_order
[16] = "default";
2544 * interface for configure zonelist ordering.
2545 * command line option "numa_zonelist_order"
2546 * = "[dD]efault - default, automatic configuration.
2547 * = "[nN]ode - order by node locality, then by zone within node
2548 * = "[zZ]one - order by zone, then by locality within zone
2551 static int __parse_numa_zonelist_order(char *s
)
2553 if (*s
== 'd' || *s
== 'D') {
2554 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2555 } else if (*s
== 'n' || *s
== 'N') {
2556 user_zonelist_order
= ZONELIST_ORDER_NODE
;
2557 } else if (*s
== 'z' || *s
== 'Z') {
2558 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
2561 "Ignoring invalid numa_zonelist_order value: "
2568 static __init
int setup_numa_zonelist_order(char *s
)
2571 return __parse_numa_zonelist_order(s
);
2574 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
2577 * sysctl handler for numa_zonelist_order
2579 int numa_zonelist_order_handler(ctl_table
*table
, int write
,
2580 void __user
*buffer
, size_t *length
,
2583 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
2585 static DEFINE_MUTEX(zl_order_mutex
);
2587 mutex_lock(&zl_order_mutex
);
2589 strcpy(saved_string
, (char*)table
->data
);
2590 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
2594 int oldval
= user_zonelist_order
;
2595 if (__parse_numa_zonelist_order((char*)table
->data
)) {
2597 * bogus value. restore saved string
2599 strncpy((char*)table
->data
, saved_string
,
2600 NUMA_ZONELIST_ORDER_LEN
);
2601 user_zonelist_order
= oldval
;
2602 } else if (oldval
!= user_zonelist_order
) {
2603 mutex_lock(&zonelists_mutex
);
2604 build_all_zonelists(NULL
);
2605 mutex_unlock(&zonelists_mutex
);
2609 mutex_unlock(&zl_order_mutex
);
2614 #define MAX_NODE_LOAD (nr_online_nodes)
2615 static int node_load
[MAX_NUMNODES
];
2618 * find_next_best_node - find the next node that should appear in a given node's fallback list
2619 * @node: node whose fallback list we're appending
2620 * @used_node_mask: nodemask_t of already used nodes
2622 * We use a number of factors to determine which is the next node that should
2623 * appear on a given node's fallback list. The node should not have appeared
2624 * already in @node's fallback list, and it should be the next closest node
2625 * according to the distance array (which contains arbitrary distance values
2626 * from each node to each node in the system), and should also prefer nodes
2627 * with no CPUs, since presumably they'll have very little allocation pressure
2628 * on them otherwise.
2629 * It returns -1 if no node is found.
2631 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
2634 int min_val
= INT_MAX
;
2636 const struct cpumask
*tmp
= cpumask_of_node(0);
2638 /* Use the local node if we haven't already */
2639 if (!node_isset(node
, *used_node_mask
)) {
2640 node_set(node
, *used_node_mask
);
2644 for_each_node_state(n
, N_HIGH_MEMORY
) {
2646 /* Don't want a node to appear more than once */
2647 if (node_isset(n
, *used_node_mask
))
2650 /* Use the distance array to find the distance */
2651 val
= node_distance(node
, n
);
2653 /* Penalize nodes under us ("prefer the next node") */
2656 /* Give preference to headless and unused nodes */
2657 tmp
= cpumask_of_node(n
);
2658 if (!cpumask_empty(tmp
))
2659 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
2661 /* Slight preference for less loaded node */
2662 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
2663 val
+= node_load
[n
];
2665 if (val
< min_val
) {
2672 node_set(best_node
, *used_node_mask
);
2679 * Build zonelists ordered by node and zones within node.
2680 * This results in maximum locality--normal zone overflows into local
2681 * DMA zone, if any--but risks exhausting DMA zone.
2683 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
2686 struct zonelist
*zonelist
;
2688 zonelist
= &pgdat
->node_zonelists
[0];
2689 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
2691 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2693 zonelist
->_zonerefs
[j
].zone
= NULL
;
2694 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2698 * Build gfp_thisnode zonelists
2700 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
2703 struct zonelist
*zonelist
;
2705 zonelist
= &pgdat
->node_zonelists
[1];
2706 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
2707 zonelist
->_zonerefs
[j
].zone
= NULL
;
2708 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2712 * Build zonelists ordered by zone and nodes within zones.
2713 * This results in conserving DMA zone[s] until all Normal memory is
2714 * exhausted, but results in overflowing to remote node while memory
2715 * may still exist in local DMA zone.
2717 static int node_order
[MAX_NUMNODES
];
2719 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
2722 int zone_type
; /* needs to be signed */
2724 struct zonelist
*zonelist
;
2726 zonelist
= &pgdat
->node_zonelists
[0];
2728 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
2729 for (j
= 0; j
< nr_nodes
; j
++) {
2730 node
= node_order
[j
];
2731 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
2732 if (populated_zone(z
)) {
2734 &zonelist
->_zonerefs
[pos
++]);
2735 check_highest_zone(zone_type
);
2739 zonelist
->_zonerefs
[pos
].zone
= NULL
;
2740 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
2743 static int default_zonelist_order(void)
2746 unsigned long low_kmem_size
,total_size
;
2750 * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
2751 * If they are really small and used heavily, the system can fall
2752 * into OOM very easily.
2753 * This function detect ZONE_DMA/DMA32 size and configures zone order.
2755 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
2758 for_each_online_node(nid
) {
2759 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
2760 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
2761 if (populated_zone(z
)) {
2762 if (zone_type
< ZONE_NORMAL
)
2763 low_kmem_size
+= z
->present_pages
;
2764 total_size
+= z
->present_pages
;
2765 } else if (zone_type
== ZONE_NORMAL
) {
2767 * If any node has only lowmem, then node order
2768 * is preferred to allow kernel allocations
2769 * locally; otherwise, they can easily infringe
2770 * on other nodes when there is an abundance of
2771 * lowmem available to allocate from.
2773 return ZONELIST_ORDER_NODE
;
2777 if (!low_kmem_size
|| /* there are no DMA area. */
2778 low_kmem_size
> total_size
/2) /* DMA/DMA32 is big. */
2779 return ZONELIST_ORDER_NODE
;
2781 * look into each node's config.
2782 * If there is a node whose DMA/DMA32 memory is very big area on
2783 * local memory, NODE_ORDER may be suitable.
2785 average_size
= total_size
/
2786 (nodes_weight(node_states
[N_HIGH_MEMORY
]) + 1);
2787 for_each_online_node(nid
) {
2790 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
2791 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
2792 if (populated_zone(z
)) {
2793 if (zone_type
< ZONE_NORMAL
)
2794 low_kmem_size
+= z
->present_pages
;
2795 total_size
+= z
->present_pages
;
2798 if (low_kmem_size
&&
2799 total_size
> average_size
&& /* ignore small node */
2800 low_kmem_size
> total_size
* 70/100)
2801 return ZONELIST_ORDER_NODE
;
2803 return ZONELIST_ORDER_ZONE
;
2806 static void set_zonelist_order(void)
2808 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
2809 current_zonelist_order
= default_zonelist_order();
2811 current_zonelist_order
= user_zonelist_order
;
2814 static void build_zonelists(pg_data_t
*pgdat
)
2818 nodemask_t used_mask
;
2819 int local_node
, prev_node
;
2820 struct zonelist
*zonelist
;
2821 int order
= current_zonelist_order
;
2823 /* initialize zonelists */
2824 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
2825 zonelist
= pgdat
->node_zonelists
+ i
;
2826 zonelist
->_zonerefs
[0].zone
= NULL
;
2827 zonelist
->_zonerefs
[0].zone_idx
= 0;
2830 /* NUMA-aware ordering of nodes */
2831 local_node
= pgdat
->node_id
;
2832 load
= nr_online_nodes
;
2833 prev_node
= local_node
;
2834 nodes_clear(used_mask
);
2836 memset(node_order
, 0, sizeof(node_order
));
2839 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
2840 int distance
= node_distance(local_node
, node
);
2843 * If another node is sufficiently far away then it is better
2844 * to reclaim pages in a zone before going off node.
2846 if (distance
> RECLAIM_DISTANCE
)
2847 zone_reclaim_mode
= 1;
2850 * We don't want to pressure a particular node.
2851 * So adding penalty to the first node in same
2852 * distance group to make it round-robin.
2854 if (distance
!= node_distance(local_node
, prev_node
))
2855 node_load
[node
] = load
;
2859 if (order
== ZONELIST_ORDER_NODE
)
2860 build_zonelists_in_node_order(pgdat
, node
);
2862 node_order
[j
++] = node
; /* remember order */
2865 if (order
== ZONELIST_ORDER_ZONE
) {
2866 /* calculate node order -- i.e., DMA last! */
2867 build_zonelists_in_zone_order(pgdat
, j
);
2870 build_thisnode_zonelists(pgdat
);
2873 /* Construct the zonelist performance cache - see further mmzone.h */
2874 static void build_zonelist_cache(pg_data_t
*pgdat
)
2876 struct zonelist
*zonelist
;
2877 struct zonelist_cache
*zlc
;
2880 zonelist
= &pgdat
->node_zonelists
[0];
2881 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
2882 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
2883 for (z
= zonelist
->_zonerefs
; z
->zone
; z
++)
2884 zlc
->z_to_n
[z
- zonelist
->_zonerefs
] = zonelist_node_idx(z
);
2887 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
2889 * Return node id of node used for "local" allocations.
2890 * I.e., first node id of first zone in arg node's generic zonelist.
2891 * Used for initializing percpu 'numa_mem', which is used primarily
2892 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
2894 int local_memory_node(int node
)
2898 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
2899 gfp_zone(GFP_KERNEL
),
2906 #else /* CONFIG_NUMA */
2908 static void set_zonelist_order(void)
2910 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
2913 static void build_zonelists(pg_data_t
*pgdat
)
2915 int node
, local_node
;
2917 struct zonelist
*zonelist
;
2919 local_node
= pgdat
->node_id
;
2921 zonelist
= &pgdat
->node_zonelists
[0];
2922 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
2925 * Now we build the zonelist so that it contains the zones
2926 * of all the other nodes.
2927 * We don't want to pressure a particular node, so when
2928 * building the zones for node N, we make sure that the
2929 * zones coming right after the local ones are those from
2930 * node N+1 (modulo N)
2932 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
2933 if (!node_online(node
))
2935 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2938 for (node
= 0; node
< local_node
; node
++) {
2939 if (!node_online(node
))
2941 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2945 zonelist
->_zonerefs
[j
].zone
= NULL
;
2946 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2949 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2950 static void build_zonelist_cache(pg_data_t
*pgdat
)
2952 pgdat
->node_zonelists
[0].zlcache_ptr
= NULL
;
2955 #endif /* CONFIG_NUMA */
2958 * Boot pageset table. One per cpu which is going to be used for all
2959 * zones and all nodes. The parameters will be set in such a way
2960 * that an item put on a list will immediately be handed over to
2961 * the buddy list. This is safe since pageset manipulation is done
2962 * with interrupts disabled.
2964 * The boot_pagesets must be kept even after bootup is complete for
2965 * unused processors and/or zones. They do play a role for bootstrapping
2966 * hotplugged processors.
2968 * zoneinfo_show() and maybe other functions do
2969 * not check if the processor is online before following the pageset pointer.
2970 * Other parts of the kernel may not check if the zone is available.
2972 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
2973 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
2974 static void setup_zone_pageset(struct zone
*zone
);
2977 * Global mutex to protect against size modification of zonelists
2978 * as well as to serialize pageset setup for the new populated zone.
2980 DEFINE_MUTEX(zonelists_mutex
);
2982 /* return values int ....just for stop_machine() */
2983 static __init_refok
int __build_all_zonelists(void *data
)
2989 memset(node_load
, 0, sizeof(node_load
));
2991 for_each_online_node(nid
) {
2992 pg_data_t
*pgdat
= NODE_DATA(nid
);
2994 build_zonelists(pgdat
);
2995 build_zonelist_cache(pgdat
);
2998 #ifdef CONFIG_MEMORY_HOTPLUG
2999 /* Setup real pagesets for the new zone */
3001 struct zone
*zone
= data
;
3002 setup_zone_pageset(zone
);
3007 * Initialize the boot_pagesets that are going to be used
3008 * for bootstrapping processors. The real pagesets for
3009 * each zone will be allocated later when the per cpu
3010 * allocator is available.
3012 * boot_pagesets are used also for bootstrapping offline
3013 * cpus if the system is already booted because the pagesets
3014 * are needed to initialize allocators on a specific cpu too.
3015 * F.e. the percpu allocator needs the page allocator which
3016 * needs the percpu allocator in order to allocate its pagesets
3017 * (a chicken-egg dilemma).
3019 for_each_possible_cpu(cpu
) {
3020 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
3022 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3024 * We now know the "local memory node" for each node--
3025 * i.e., the node of the first zone in the generic zonelist.
3026 * Set up numa_mem percpu variable for on-line cpus. During
3027 * boot, only the boot cpu should be on-line; we'll init the
3028 * secondary cpus' numa_mem as they come on-line. During
3029 * node/memory hotplug, we'll fixup all on-line cpus.
3031 if (cpu_online(cpu
))
3032 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
3040 * Called with zonelists_mutex held always
3041 * unless system_state == SYSTEM_BOOTING.
3043 void build_all_zonelists(void *data
)
3045 set_zonelist_order();
3047 if (system_state
== SYSTEM_BOOTING
) {
3048 __build_all_zonelists(NULL
);
3049 mminit_verify_zonelist();
3050 cpuset_init_current_mems_allowed();
3052 /* we have to stop all cpus to guarantee there is no user
3054 stop_machine(__build_all_zonelists
, data
, NULL
);
3055 /* cpuset refresh routine should be here */
3057 vm_total_pages
= nr_free_pagecache_pages();
3059 * Disable grouping by mobility if the number of pages in the
3060 * system is too low to allow the mechanism to work. It would be
3061 * more accurate, but expensive to check per-zone. This check is
3062 * made on memory-hotadd so a system can start with mobility
3063 * disabled and enable it later
3065 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
3066 page_group_by_mobility_disabled
= 1;
3068 page_group_by_mobility_disabled
= 0;
3070 printk("Built %i zonelists in %s order, mobility grouping %s. "
3071 "Total pages: %ld\n",
3073 zonelist_order_name
[current_zonelist_order
],
3074 page_group_by_mobility_disabled
? "off" : "on",
3077 printk("Policy zone: %s\n", zone_names
[policy_zone
]);
3082 * Helper functions to size the waitqueue hash table.
3083 * Essentially these want to choose hash table sizes sufficiently
3084 * large so that collisions trying to wait on pages are rare.
3085 * But in fact, the number of active page waitqueues on typical
3086 * systems is ridiculously low, less than 200. So this is even
3087 * conservative, even though it seems large.
3089 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
3090 * waitqueues, i.e. the size of the waitq table given the number of pages.
3092 #define PAGES_PER_WAITQUEUE 256
3094 #ifndef CONFIG_MEMORY_HOTPLUG
3095 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3097 unsigned long size
= 1;
3099 pages
/= PAGES_PER_WAITQUEUE
;
3101 while (size
< pages
)
3105 * Once we have dozens or even hundreds of threads sleeping
3106 * on IO we've got bigger problems than wait queue collision.
3107 * Limit the size of the wait table to a reasonable size.
3109 size
= min(size
, 4096UL);
3111 return max(size
, 4UL);
3115 * A zone's size might be changed by hot-add, so it is not possible to determine
3116 * a suitable size for its wait_table. So we use the maximum size now.
3118 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
3120 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
3121 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
3122 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
3124 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
3125 * or more by the traditional way. (See above). It equals:
3127 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
3128 * ia64(16K page size) : = ( 8G + 4M)byte.
3129 * powerpc (64K page size) : = (32G +16M)byte.
3131 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3138 * This is an integer logarithm so that shifts can be used later
3139 * to extract the more random high bits from the multiplicative
3140 * hash function before the remainder is taken.
3142 static inline unsigned long wait_table_bits(unsigned long size
)
3147 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
3150 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3151 * of blocks reserved is based on min_wmark_pages(zone). The memory within
3152 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
3153 * higher will lead to a bigger reserve which will get freed as contiguous
3154 * blocks as reclaim kicks in
3156 static void setup_zone_migrate_reserve(struct zone
*zone
)
3158 unsigned long start_pfn
, pfn
, end_pfn
;
3160 unsigned long block_migratetype
;
3163 /* Get the start pfn, end pfn and the number of blocks to reserve */
3164 start_pfn
= zone
->zone_start_pfn
;
3165 end_pfn
= start_pfn
+ zone
->spanned_pages
;
3166 reserve
= roundup(min_wmark_pages(zone
), pageblock_nr_pages
) >>
3170 * Reserve blocks are generally in place to help high-order atomic
3171 * allocations that are short-lived. A min_free_kbytes value that
3172 * would result in more than 2 reserve blocks for atomic allocations
3173 * is assumed to be in place to help anti-fragmentation for the
3174 * future allocation of hugepages at runtime.
3176 reserve
= min(2, reserve
);
3178 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
3179 if (!pfn_valid(pfn
))
3181 page
= pfn_to_page(pfn
);
3183 /* Watch out for overlapping nodes */
3184 if (page_to_nid(page
) != zone_to_nid(zone
))
3187 /* Blocks with reserved pages will never free, skip them. */
3188 if (PageReserved(page
))
3191 block_migratetype
= get_pageblock_migratetype(page
);
3193 /* If this block is reserved, account for it */
3194 if (reserve
> 0 && block_migratetype
== MIGRATE_RESERVE
) {
3199 /* Suitable for reserving if this block is movable */
3200 if (reserve
> 0 && block_migratetype
== MIGRATE_MOVABLE
) {
3201 set_pageblock_migratetype(page
, MIGRATE_RESERVE
);
3202 move_freepages_block(zone
, page
, MIGRATE_RESERVE
);
3208 * If the reserve is met and this is a previous reserved block,
3211 if (block_migratetype
== MIGRATE_RESERVE
) {
3212 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
3213 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
3219 * Initially all pages are reserved - free ones are freed
3220 * up by free_all_bootmem() once the early boot process is
3221 * done. Non-atomic initialization, single-pass.
3223 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
3224 unsigned long start_pfn
, enum memmap_context context
)
3227 unsigned long end_pfn
= start_pfn
+ size
;
3231 if (highest_memmap_pfn
< end_pfn
- 1)
3232 highest_memmap_pfn
= end_pfn
- 1;
3234 z
= &NODE_DATA(nid
)->node_zones
[zone
];
3235 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
3237 * There can be holes in boot-time mem_map[]s
3238 * handed to this function. They do not
3239 * exist on hotplugged memory.
3241 if (context
== MEMMAP_EARLY
) {
3242 if (!early_pfn_valid(pfn
))
3244 if (!early_pfn_in_nid(pfn
, nid
))
3247 page
= pfn_to_page(pfn
);
3248 set_page_links(page
, zone
, nid
, pfn
);
3249 mminit_verify_page_links(page
, zone
, nid
, pfn
);
3250 init_page_count(page
);
3251 reset_page_mapcount(page
);
3252 SetPageReserved(page
);
3254 * Mark the block movable so that blocks are reserved for
3255 * movable at startup. This will force kernel allocations
3256 * to reserve their blocks rather than leaking throughout
3257 * the address space during boot when many long-lived
3258 * kernel allocations are made. Later some blocks near
3259 * the start are marked MIGRATE_RESERVE by
3260 * setup_zone_migrate_reserve()
3262 * bitmap is created for zone's valid pfn range. but memmap
3263 * can be created for invalid pages (for alignment)
3264 * check here not to call set_pageblock_migratetype() against
3267 if ((z
->zone_start_pfn
<= pfn
)
3268 && (pfn
< z
->zone_start_pfn
+ z
->spanned_pages
)
3269 && !(pfn
& (pageblock_nr_pages
- 1)))
3270 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
3272 INIT_LIST_HEAD(&page
->lru
);
3273 #ifdef WANT_PAGE_VIRTUAL
3274 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
3275 if (!is_highmem_idx(zone
))
3276 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
3281 static void __meminit
zone_init_free_lists(struct zone
*zone
)
3284 for_each_migratetype_order(order
, t
) {
3285 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
3286 zone
->free_area
[order
].nr_free
= 0;
3290 #ifndef __HAVE_ARCH_MEMMAP_INIT
3291 #define memmap_init(size, nid, zone, start_pfn) \
3292 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
3295 static int zone_batchsize(struct zone
*zone
)
3301 * The per-cpu-pages pools are set to around 1000th of the
3302 * size of the zone. But no more than 1/2 of a meg.
3304 * OK, so we don't know how big the cache is. So guess.
3306 batch
= zone
->present_pages
/ 1024;
3307 if (batch
* PAGE_SIZE
> 512 * 1024)
3308 batch
= (512 * 1024) / PAGE_SIZE
;
3309 batch
/= 4; /* We effectively *= 4 below */
3314 * Clamp the batch to a 2^n - 1 value. Having a power
3315 * of 2 value was found to be more likely to have
3316 * suboptimal cache aliasing properties in some cases.
3318 * For example if 2 tasks are alternately allocating
3319 * batches of pages, one task can end up with a lot
3320 * of pages of one half of the possible page colors
3321 * and the other with pages of the other colors.
3323 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
3328 /* The deferral and batching of frees should be suppressed under NOMMU
3331 * The problem is that NOMMU needs to be able to allocate large chunks
3332 * of contiguous memory as there's no hardware page translation to
3333 * assemble apparent contiguous memory from discontiguous pages.
3335 * Queueing large contiguous runs of pages for batching, however,
3336 * causes the pages to actually be freed in smaller chunks. As there
3337 * can be a significant delay between the individual batches being
3338 * recycled, this leads to the once large chunks of space being
3339 * fragmented and becoming unavailable for high-order allocations.
3345 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
3347 struct per_cpu_pages
*pcp
;
3350 memset(p
, 0, sizeof(*p
));
3354 pcp
->high
= 6 * batch
;
3355 pcp
->batch
= max(1UL, 1 * batch
);
3356 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
3357 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
3361 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
3362 * to the value high for the pageset p.
3365 static void setup_pagelist_highmark(struct per_cpu_pageset
*p
,
3368 struct per_cpu_pages
*pcp
;
3372 pcp
->batch
= max(1UL, high
/4);
3373 if ((high
/4) > (PAGE_SHIFT
* 8))
3374 pcp
->batch
= PAGE_SHIFT
* 8;
3377 static __meminit
void setup_zone_pageset(struct zone
*zone
)
3381 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
3383 for_each_possible_cpu(cpu
) {
3384 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
3386 setup_pageset(pcp
, zone_batchsize(zone
));
3388 if (percpu_pagelist_fraction
)
3389 setup_pagelist_highmark(pcp
,
3390 (zone
->present_pages
/
3391 percpu_pagelist_fraction
));
3396 * Allocate per cpu pagesets and initialize them.
3397 * Before this call only boot pagesets were available.
3399 void __init
setup_per_cpu_pageset(void)
3403 for_each_populated_zone(zone
)
3404 setup_zone_pageset(zone
);
3407 static noinline __init_refok
3408 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
3411 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
3415 * The per-page waitqueue mechanism uses hashed waitqueues
3418 zone
->wait_table_hash_nr_entries
=
3419 wait_table_hash_nr_entries(zone_size_pages
);
3420 zone
->wait_table_bits
=
3421 wait_table_bits(zone
->wait_table_hash_nr_entries
);
3422 alloc_size
= zone
->wait_table_hash_nr_entries
3423 * sizeof(wait_queue_head_t
);
3425 if (!slab_is_available()) {
3426 zone
->wait_table
= (wait_queue_head_t
*)
3427 alloc_bootmem_node(pgdat
, alloc_size
);
3430 * This case means that a zone whose size was 0 gets new memory
3431 * via memory hot-add.
3432 * But it may be the case that a new node was hot-added. In
3433 * this case vmalloc() will not be able to use this new node's
3434 * memory - this wait_table must be initialized to use this new
3435 * node itself as well.
3436 * To use this new node's memory, further consideration will be
3439 zone
->wait_table
= vmalloc(alloc_size
);
3441 if (!zone
->wait_table
)
3444 for(i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
3445 init_waitqueue_head(zone
->wait_table
+ i
);
3450 static int __zone_pcp_update(void *data
)
3452 struct zone
*zone
= data
;
3454 unsigned long batch
= zone_batchsize(zone
), flags
;
3456 for_each_possible_cpu(cpu
) {
3457 struct per_cpu_pageset
*pset
;
3458 struct per_cpu_pages
*pcp
;
3460 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
3463 local_irq_save(flags
);
3464 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
3465 setup_pageset(pset
, batch
);
3466 local_irq_restore(flags
);
3471 void zone_pcp_update(struct zone
*zone
)
3473 stop_machine(__zone_pcp_update
, zone
, NULL
);
3476 static __meminit
void zone_pcp_init(struct zone
*zone
)
3479 * per cpu subsystem is not up at this point. The following code
3480 * relies on the ability of the linker to provide the
3481 * offset of a (static) per cpu variable into the per cpu area.
3483 zone
->pageset
= &boot_pageset
;
3485 if (zone
->present_pages
)
3486 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
3487 zone
->name
, zone
->present_pages
,
3488 zone_batchsize(zone
));
3491 __meminit
int init_currently_empty_zone(struct zone
*zone
,
3492 unsigned long zone_start_pfn
,
3494 enum memmap_context context
)
3496 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
3498 ret
= zone_wait_table_init(zone
, size
);
3501 pgdat
->nr_zones
= zone_idx(zone
) + 1;
3503 zone
->zone_start_pfn
= zone_start_pfn
;
3505 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
3506 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
3508 (unsigned long)zone_idx(zone
),
3509 zone_start_pfn
, (zone_start_pfn
+ size
));
3511 zone_init_free_lists(zone
);
3516 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3518 * Basic iterator support. Return the first range of PFNs for a node
3519 * Note: nid == MAX_NUMNODES returns first region regardless of node
3521 static int __meminit
first_active_region_index_in_nid(int nid
)
3525 for (i
= 0; i
< nr_nodemap_entries
; i
++)
3526 if (nid
== MAX_NUMNODES
|| early_node_map
[i
].nid
== nid
)
3533 * Basic iterator support. Return the next active range of PFNs for a node
3534 * Note: nid == MAX_NUMNODES returns next region regardless of node
3536 static int __meminit
next_active_region_index_in_nid(int index
, int nid
)
3538 for (index
= index
+ 1; index
< nr_nodemap_entries
; index
++)
3539 if (nid
== MAX_NUMNODES
|| early_node_map
[index
].nid
== nid
)
3545 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
3547 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
3548 * Architectures may implement their own version but if add_active_range()
3549 * was used and there are no special requirements, this is a convenient
3552 int __meminit
__early_pfn_to_nid(unsigned long pfn
)
3556 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
3557 unsigned long start_pfn
= early_node_map
[i
].start_pfn
;
3558 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
3560 if (start_pfn
<= pfn
&& pfn
< end_pfn
)
3561 return early_node_map
[i
].nid
;
3563 /* This is a memory hole */
3566 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
3568 int __meminit
early_pfn_to_nid(unsigned long pfn
)
3572 nid
= __early_pfn_to_nid(pfn
);
3575 /* just returns 0 */
3579 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
3580 bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
3584 nid
= __early_pfn_to_nid(pfn
);
3585 if (nid
>= 0 && nid
!= node
)
3591 /* Basic iterator support to walk early_node_map[] */
3592 #define for_each_active_range_index_in_nid(i, nid) \
3593 for (i = first_active_region_index_in_nid(nid); i != -1; \
3594 i = next_active_region_index_in_nid(i, nid))
3597 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
3598 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
3599 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
3601 * If an architecture guarantees that all ranges registered with
3602 * add_active_ranges() contain no holes and may be freed, this
3603 * this function may be used instead of calling free_bootmem() manually.
3605 void __init
free_bootmem_with_active_regions(int nid
,
3606 unsigned long max_low_pfn
)
3610 for_each_active_range_index_in_nid(i
, nid
) {
3611 unsigned long size_pages
= 0;
3612 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
3614 if (early_node_map
[i
].start_pfn
>= max_low_pfn
)
3617 if (end_pfn
> max_low_pfn
)
3618 end_pfn
= max_low_pfn
;
3620 size_pages
= end_pfn
- early_node_map
[i
].start_pfn
;
3621 free_bootmem_node(NODE_DATA(early_node_map
[i
].nid
),
3622 PFN_PHYS(early_node_map
[i
].start_pfn
),
3623 size_pages
<< PAGE_SHIFT
);
3627 #ifdef CONFIG_HAVE_MEMBLOCK
3628 u64 __init
find_memory_core_early(int nid
, u64 size
, u64 align
,
3629 u64 goal
, u64 limit
)
3633 /* Need to go over early_node_map to find out good range for node */
3634 for_each_active_range_index_in_nid(i
, nid
) {
3636 u64 ei_start
, ei_last
;
3637 u64 final_start
, final_end
;
3639 ei_last
= early_node_map
[i
].end_pfn
;
3640 ei_last
<<= PAGE_SHIFT
;
3641 ei_start
= early_node_map
[i
].start_pfn
;
3642 ei_start
<<= PAGE_SHIFT
;
3644 final_start
= max(ei_start
, goal
);
3645 final_end
= min(ei_last
, limit
);
3647 if (final_start
>= final_end
)
3650 addr
= memblock_find_in_range(final_start
, final_end
, size
, align
);
3652 if (addr
== MEMBLOCK_ERROR
)
3658 return MEMBLOCK_ERROR
;
3662 int __init
add_from_early_node_map(struct range
*range
, int az
,
3663 int nr_range
, int nid
)
3668 /* need to go over early_node_map to find out good range for node */
3669 for_each_active_range_index_in_nid(i
, nid
) {
3670 start
= early_node_map
[i
].start_pfn
;
3671 end
= early_node_map
[i
].end_pfn
;
3672 nr_range
= add_range(range
, az
, nr_range
, start
, end
);
3677 #ifdef CONFIG_NO_BOOTMEM
3678 void * __init
__alloc_memory_core_early(int nid
, u64 size
, u64 align
,
3679 u64 goal
, u64 limit
)
3684 if (limit
> memblock
.current_limit
)
3685 limit
= memblock
.current_limit
;
3687 addr
= find_memory_core_early(nid
, size
, align
, goal
, limit
);
3689 if (addr
== MEMBLOCK_ERROR
)
3692 ptr
= phys_to_virt(addr
);
3693 memset(ptr
, 0, size
);
3694 memblock_x86_reserve_range(addr
, addr
+ size
, "BOOTMEM");
3696 * The min_count is set to 0 so that bootmem allocated blocks
3697 * are never reported as leaks.
3699 kmemleak_alloc(ptr
, size
, 0, 0);
3705 void __init
work_with_active_regions(int nid
, work_fn_t work_fn
, void *data
)
3710 for_each_active_range_index_in_nid(i
, nid
) {
3711 ret
= work_fn(early_node_map
[i
].start_pfn
,
3712 early_node_map
[i
].end_pfn
, data
);
3718 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3719 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3721 * If an architecture guarantees that all ranges registered with
3722 * add_active_ranges() contain no holes and may be freed, this
3723 * function may be used instead of calling memory_present() manually.
3725 void __init
sparse_memory_present_with_active_regions(int nid
)
3729 for_each_active_range_index_in_nid(i
, nid
)
3730 memory_present(early_node_map
[i
].nid
,
3731 early_node_map
[i
].start_pfn
,
3732 early_node_map
[i
].end_pfn
);
3736 * get_pfn_range_for_nid - Return the start and end page frames for a node
3737 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
3738 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
3739 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
3741 * It returns the start and end page frame of a node based on information
3742 * provided by an arch calling add_active_range(). If called for a node
3743 * with no available memory, a warning is printed and the start and end
3746 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
3747 unsigned long *start_pfn
, unsigned long *end_pfn
)
3753 for_each_active_range_index_in_nid(i
, nid
) {
3754 *start_pfn
= min(*start_pfn
, early_node_map
[i
].start_pfn
);
3755 *end_pfn
= max(*end_pfn
, early_node_map
[i
].end_pfn
);
3758 if (*start_pfn
== -1UL)
3763 * This finds a zone that can be used for ZONE_MOVABLE pages. The
3764 * assumption is made that zones within a node are ordered in monotonic
3765 * increasing memory addresses so that the "highest" populated zone is used
3767 static void __init
find_usable_zone_for_movable(void)
3770 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
3771 if (zone_index
== ZONE_MOVABLE
)
3774 if (arch_zone_highest_possible_pfn
[zone_index
] >
3775 arch_zone_lowest_possible_pfn
[zone_index
])
3779 VM_BUG_ON(zone_index
== -1);
3780 movable_zone
= zone_index
;
3784 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
3785 * because it is sized independant of architecture. Unlike the other zones,
3786 * the starting point for ZONE_MOVABLE is not fixed. It may be different
3787 * in each node depending on the size of each node and how evenly kernelcore
3788 * is distributed. This helper function adjusts the zone ranges
3789 * provided by the architecture for a given node by using the end of the
3790 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
3791 * zones within a node are in order of monotonic increases memory addresses
3793 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
3794 unsigned long zone_type
,
3795 unsigned long node_start_pfn
,
3796 unsigned long node_end_pfn
,
3797 unsigned long *zone_start_pfn
,
3798 unsigned long *zone_end_pfn
)
3800 /* Only adjust if ZONE_MOVABLE is on this node */
3801 if (zone_movable_pfn
[nid
]) {
3802 /* Size ZONE_MOVABLE */
3803 if (zone_type
== ZONE_MOVABLE
) {
3804 *zone_start_pfn
= zone_movable_pfn
[nid
];
3805 *zone_end_pfn
= min(node_end_pfn
,
3806 arch_zone_highest_possible_pfn
[movable_zone
]);
3808 /* Adjust for ZONE_MOVABLE starting within this range */
3809 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
3810 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
3811 *zone_end_pfn
= zone_movable_pfn
[nid
];
3813 /* Check if this whole range is within ZONE_MOVABLE */
3814 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
3815 *zone_start_pfn
= *zone_end_pfn
;
3820 * Return the number of pages a zone spans in a node, including holes
3821 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
3823 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3824 unsigned long zone_type
,
3825 unsigned long *ignored
)
3827 unsigned long node_start_pfn
, node_end_pfn
;
3828 unsigned long zone_start_pfn
, zone_end_pfn
;
3830 /* Get the start and end of the node and zone */
3831 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
3832 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
3833 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
3834 adjust_zone_range_for_zone_movable(nid
, zone_type
,
3835 node_start_pfn
, node_end_pfn
,
3836 &zone_start_pfn
, &zone_end_pfn
);
3838 /* Check that this node has pages within the zone's required range */
3839 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
3842 /* Move the zone boundaries inside the node if necessary */
3843 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
3844 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
3846 /* Return the spanned pages */
3847 return zone_end_pfn
- zone_start_pfn
;
3851 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
3852 * then all holes in the requested range will be accounted for.
3854 unsigned long __meminit
__absent_pages_in_range(int nid
,
3855 unsigned long range_start_pfn
,
3856 unsigned long range_end_pfn
)
3859 unsigned long prev_end_pfn
= 0, hole_pages
= 0;
3860 unsigned long start_pfn
;
3862 /* Find the end_pfn of the first active range of pfns in the node */
3863 i
= first_active_region_index_in_nid(nid
);
3867 prev_end_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
3869 /* Account for ranges before physical memory on this node */
3870 if (early_node_map
[i
].start_pfn
> range_start_pfn
)
3871 hole_pages
= prev_end_pfn
- range_start_pfn
;
3873 /* Find all holes for the zone within the node */
3874 for (; i
!= -1; i
= next_active_region_index_in_nid(i
, nid
)) {
3876 /* No need to continue if prev_end_pfn is outside the zone */
3877 if (prev_end_pfn
>= range_end_pfn
)
3880 /* Make sure the end of the zone is not within the hole */
3881 start_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
3882 prev_end_pfn
= max(prev_end_pfn
, range_start_pfn
);
3884 /* Update the hole size cound and move on */
3885 if (start_pfn
> range_start_pfn
) {
3886 BUG_ON(prev_end_pfn
> start_pfn
);
3887 hole_pages
+= start_pfn
- prev_end_pfn
;
3889 prev_end_pfn
= early_node_map
[i
].end_pfn
;
3892 /* Account for ranges past physical memory on this node */
3893 if (range_end_pfn
> prev_end_pfn
)
3894 hole_pages
+= range_end_pfn
-
3895 max(range_start_pfn
, prev_end_pfn
);
3901 * absent_pages_in_range - Return number of page frames in holes within a range
3902 * @start_pfn: The start PFN to start searching for holes
3903 * @end_pfn: The end PFN to stop searching for holes
3905 * It returns the number of pages frames in memory holes within a range.
3907 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
3908 unsigned long end_pfn
)
3910 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
3913 /* Return the number of page frames in holes in a zone on a node */
3914 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
3915 unsigned long zone_type
,
3916 unsigned long *ignored
)
3918 unsigned long node_start_pfn
, node_end_pfn
;
3919 unsigned long zone_start_pfn
, zone_end_pfn
;
3921 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
3922 zone_start_pfn
= max(arch_zone_lowest_possible_pfn
[zone_type
],
3924 zone_end_pfn
= min(arch_zone_highest_possible_pfn
[zone_type
],
3927 adjust_zone_range_for_zone_movable(nid
, zone_type
,
3928 node_start_pfn
, node_end_pfn
,
3929 &zone_start_pfn
, &zone_end_pfn
);
3930 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
3934 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3935 unsigned long zone_type
,
3936 unsigned long *zones_size
)
3938 return zones_size
[zone_type
];
3941 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
3942 unsigned long zone_type
,
3943 unsigned long *zholes_size
)
3948 return zholes_size
[zone_type
];
3953 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
3954 unsigned long *zones_size
, unsigned long *zholes_size
)
3956 unsigned long realtotalpages
, totalpages
= 0;
3959 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3960 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
3962 pgdat
->node_spanned_pages
= totalpages
;
3964 realtotalpages
= totalpages
;
3965 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3967 zone_absent_pages_in_node(pgdat
->node_id
, i
,
3969 pgdat
->node_present_pages
= realtotalpages
;
3970 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
3974 #ifndef CONFIG_SPARSEMEM
3976 * Calculate the size of the zone->blockflags rounded to an unsigned long
3977 * Start by making sure zonesize is a multiple of pageblock_order by rounding
3978 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
3979 * round what is now in bits to nearest long in bits, then return it in
3982 static unsigned long __init
usemap_size(unsigned long zonesize
)
3984 unsigned long usemapsize
;
3986 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
3987 usemapsize
= usemapsize
>> pageblock_order
;
3988 usemapsize
*= NR_PAGEBLOCK_BITS
;
3989 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
3991 return usemapsize
/ 8;
3994 static void __init
setup_usemap(struct pglist_data
*pgdat
,
3995 struct zone
*zone
, unsigned long zonesize
)
3997 unsigned long usemapsize
= usemap_size(zonesize
);
3998 zone
->pageblock_flags
= NULL
;
4000 zone
->pageblock_flags
= alloc_bootmem_node(pgdat
, usemapsize
);
4003 static void inline setup_usemap(struct pglist_data
*pgdat
,
4004 struct zone
*zone
, unsigned long zonesize
) {}
4005 #endif /* CONFIG_SPARSEMEM */
4007 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4009 /* Return a sensible default order for the pageblock size. */
4010 static inline int pageblock_default_order(void)
4012 if (HPAGE_SHIFT
> PAGE_SHIFT
)
4013 return HUGETLB_PAGE_ORDER
;
4018 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4019 static inline void __init
set_pageblock_order(unsigned int order
)
4021 /* Check that pageblock_nr_pages has not already been setup */
4022 if (pageblock_order
)
4026 * Assume the largest contiguous order of interest is a huge page.
4027 * This value may be variable depending on boot parameters on IA64
4029 pageblock_order
= order
;
4031 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4034 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4035 * and pageblock_default_order() are unused as pageblock_order is set
4036 * at compile-time. See include/linux/pageblock-flags.h for the values of
4037 * pageblock_order based on the kernel config
4039 static inline int pageblock_default_order(unsigned int order
)
4043 #define set_pageblock_order(x) do {} while (0)
4045 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4048 * Set up the zone data structures:
4049 * - mark all pages reserved
4050 * - mark all memory queues empty
4051 * - clear the memory bitmaps
4053 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
,
4054 unsigned long *zones_size
, unsigned long *zholes_size
)
4057 int nid
= pgdat
->node_id
;
4058 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
4061 pgdat_resize_init(pgdat
);
4062 pgdat
->nr_zones
= 0;
4063 init_waitqueue_head(&pgdat
->kswapd_wait
);
4064 pgdat
->kswapd_max_order
= 0;
4065 pgdat_page_cgroup_init(pgdat
);
4067 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4068 struct zone
*zone
= pgdat
->node_zones
+ j
;
4069 unsigned long size
, realsize
, memmap_pages
;
4072 size
= zone_spanned_pages_in_node(nid
, j
, zones_size
);
4073 realsize
= size
- zone_absent_pages_in_node(nid
, j
,
4077 * Adjust realsize so that it accounts for how much memory
4078 * is used by this zone for memmap. This affects the watermark
4079 * and per-cpu initialisations
4082 PAGE_ALIGN(size
* sizeof(struct page
)) >> PAGE_SHIFT
;
4083 if (realsize
>= memmap_pages
) {
4084 realsize
-= memmap_pages
;
4087 " %s zone: %lu pages used for memmap\n",
4088 zone_names
[j
], memmap_pages
);
4091 " %s zone: %lu pages exceeds realsize %lu\n",
4092 zone_names
[j
], memmap_pages
, realsize
);
4094 /* Account for reserved pages */
4095 if (j
== 0 && realsize
> dma_reserve
) {
4096 realsize
-= dma_reserve
;
4097 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
4098 zone_names
[0], dma_reserve
);
4101 if (!is_highmem_idx(j
))
4102 nr_kernel_pages
+= realsize
;
4103 nr_all_pages
+= realsize
;
4105 zone
->spanned_pages
= size
;
4106 zone
->present_pages
= realsize
;
4109 zone
->min_unmapped_pages
= (realsize
*sysctl_min_unmapped_ratio
)
4111 zone
->min_slab_pages
= (realsize
* sysctl_min_slab_ratio
) / 100;
4113 zone
->name
= zone_names
[j
];
4114 spin_lock_init(&zone
->lock
);
4115 spin_lock_init(&zone
->lru_lock
);
4116 zone_seqlock_init(zone
);
4117 zone
->zone_pgdat
= pgdat
;
4119 zone_pcp_init(zone
);
4121 INIT_LIST_HEAD(&zone
->lru
[l
].list
);
4122 zone
->reclaim_stat
.nr_saved_scan
[l
] = 0;
4124 zone
->reclaim_stat
.recent_rotated
[0] = 0;
4125 zone
->reclaim_stat
.recent_rotated
[1] = 0;
4126 zone
->reclaim_stat
.recent_scanned
[0] = 0;
4127 zone
->reclaim_stat
.recent_scanned
[1] = 0;
4128 zap_zone_vm_stats(zone
);
4133 set_pageblock_order(pageblock_default_order());
4134 setup_usemap(pgdat
, zone
, size
);
4135 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
4136 size
, MEMMAP_EARLY
);
4138 memmap_init(size
, nid
, j
, zone_start_pfn
);
4139 zone_start_pfn
+= size
;
4143 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
4145 /* Skip empty nodes */
4146 if (!pgdat
->node_spanned_pages
)
4149 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4150 /* ia64 gets its own node_mem_map, before this, without bootmem */
4151 if (!pgdat
->node_mem_map
) {
4152 unsigned long size
, start
, end
;
4156 * The zone's endpoints aren't required to be MAX_ORDER
4157 * aligned but the node_mem_map endpoints must be in order
4158 * for the buddy allocator to function correctly.
4160 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
4161 end
= pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
4162 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
4163 size
= (end
- start
) * sizeof(struct page
);
4164 map
= alloc_remap(pgdat
->node_id
, size
);
4166 map
= alloc_bootmem_node(pgdat
, size
);
4167 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
4169 #ifndef CONFIG_NEED_MULTIPLE_NODES
4171 * With no DISCONTIG, the global mem_map is just set as node 0's
4173 if (pgdat
== NODE_DATA(0)) {
4174 mem_map
= NODE_DATA(0)->node_mem_map
;
4175 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
4176 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
4177 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
4178 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
4181 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
4184 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
4185 unsigned long node_start_pfn
, unsigned long *zholes_size
)
4187 pg_data_t
*pgdat
= NODE_DATA(nid
);
4189 pgdat
->node_id
= nid
;
4190 pgdat
->node_start_pfn
= node_start_pfn
;
4191 calculate_node_totalpages(pgdat
, zones_size
, zholes_size
);
4193 alloc_node_mem_map(pgdat
);
4194 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4195 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
4196 nid
, (unsigned long)pgdat
,
4197 (unsigned long)pgdat
->node_mem_map
);
4200 free_area_init_core(pgdat
, zones_size
, zholes_size
);
4203 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
4205 #if MAX_NUMNODES > 1
4207 * Figure out the number of possible node ids.
4209 static void __init
setup_nr_node_ids(void)
4212 unsigned int highest
= 0;
4214 for_each_node_mask(node
, node_possible_map
)
4216 nr_node_ids
= highest
+ 1;
4219 static inline void setup_nr_node_ids(void)
4225 * add_active_range - Register a range of PFNs backed by physical memory
4226 * @nid: The node ID the range resides on
4227 * @start_pfn: The start PFN of the available physical memory
4228 * @end_pfn: The end PFN of the available physical memory
4230 * These ranges are stored in an early_node_map[] and later used by
4231 * free_area_init_nodes() to calculate zone sizes and holes. If the
4232 * range spans a memory hole, it is up to the architecture to ensure
4233 * the memory is not freed by the bootmem allocator. If possible
4234 * the range being registered will be merged with existing ranges.
4236 void __init
add_active_range(unsigned int nid
, unsigned long start_pfn
,
4237 unsigned long end_pfn
)
4241 mminit_dprintk(MMINIT_TRACE
, "memory_register",
4242 "Entering add_active_range(%d, %#lx, %#lx) "
4243 "%d entries of %d used\n",
4244 nid
, start_pfn
, end_pfn
,
4245 nr_nodemap_entries
, MAX_ACTIVE_REGIONS
);
4247 mminit_validate_memmodel_limits(&start_pfn
, &end_pfn
);
4249 /* Merge with existing active regions if possible */
4250 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
4251 if (early_node_map
[i
].nid
!= nid
)
4254 /* Skip if an existing region covers this new one */
4255 if (start_pfn
>= early_node_map
[i
].start_pfn
&&
4256 end_pfn
<= early_node_map
[i
].end_pfn
)
4259 /* Merge forward if suitable */
4260 if (start_pfn
<= early_node_map
[i
].end_pfn
&&
4261 end_pfn
> early_node_map
[i
].end_pfn
) {
4262 early_node_map
[i
].end_pfn
= end_pfn
;
4266 /* Merge backward if suitable */
4267 if (start_pfn
< early_node_map
[i
].start_pfn
&&
4268 end_pfn
>= early_node_map
[i
].start_pfn
) {
4269 early_node_map
[i
].start_pfn
= start_pfn
;
4274 /* Check that early_node_map is large enough */
4275 if (i
>= MAX_ACTIVE_REGIONS
) {
4276 printk(KERN_CRIT
"More than %d memory regions, truncating\n",
4277 MAX_ACTIVE_REGIONS
);
4281 early_node_map
[i
].nid
= nid
;
4282 early_node_map
[i
].start_pfn
= start_pfn
;
4283 early_node_map
[i
].end_pfn
= end_pfn
;
4284 nr_nodemap_entries
= i
+ 1;
4288 * remove_active_range - Shrink an existing registered range of PFNs
4289 * @nid: The node id the range is on that should be shrunk
4290 * @start_pfn: The new PFN of the range
4291 * @end_pfn: The new PFN of the range
4293 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
4294 * The map is kept near the end physical page range that has already been
4295 * registered. This function allows an arch to shrink an existing registered
4298 void __init
remove_active_range(unsigned int nid
, unsigned long start_pfn
,
4299 unsigned long end_pfn
)
4304 printk(KERN_DEBUG
"remove_active_range (%d, %lu, %lu)\n",
4305 nid
, start_pfn
, end_pfn
);
4307 /* Find the old active region end and shrink */
4308 for_each_active_range_index_in_nid(i
, nid
) {
4309 if (early_node_map
[i
].start_pfn
>= start_pfn
&&
4310 early_node_map
[i
].end_pfn
<= end_pfn
) {
4312 early_node_map
[i
].start_pfn
= 0;
4313 early_node_map
[i
].end_pfn
= 0;
4317 if (early_node_map
[i
].start_pfn
< start_pfn
&&
4318 early_node_map
[i
].end_pfn
> start_pfn
) {
4319 unsigned long temp_end_pfn
= early_node_map
[i
].end_pfn
;
4320 early_node_map
[i
].end_pfn
= start_pfn
;
4321 if (temp_end_pfn
> end_pfn
)
4322 add_active_range(nid
, end_pfn
, temp_end_pfn
);
4325 if (early_node_map
[i
].start_pfn
>= start_pfn
&&
4326 early_node_map
[i
].end_pfn
> end_pfn
&&
4327 early_node_map
[i
].start_pfn
< end_pfn
) {
4328 early_node_map
[i
].start_pfn
= end_pfn
;
4336 /* remove the blank ones */
4337 for (i
= nr_nodemap_entries
- 1; i
> 0; i
--) {
4338 if (early_node_map
[i
].nid
!= nid
)
4340 if (early_node_map
[i
].end_pfn
)
4342 /* we found it, get rid of it */
4343 for (j
= i
; j
< nr_nodemap_entries
- 1; j
++)
4344 memcpy(&early_node_map
[j
], &early_node_map
[j
+1],
4345 sizeof(early_node_map
[j
]));
4346 j
= nr_nodemap_entries
- 1;
4347 memset(&early_node_map
[j
], 0, sizeof(early_node_map
[j
]));
4348 nr_nodemap_entries
--;
4353 * remove_all_active_ranges - Remove all currently registered regions
4355 * During discovery, it may be found that a table like SRAT is invalid
4356 * and an alternative discovery method must be used. This function removes
4357 * all currently registered regions.
4359 void __init
remove_all_active_ranges(void)
4361 memset(early_node_map
, 0, sizeof(early_node_map
));
4362 nr_nodemap_entries
= 0;
4365 /* Compare two active node_active_regions */
4366 static int __init
cmp_node_active_region(const void *a
, const void *b
)
4368 struct node_active_region
*arange
= (struct node_active_region
*)a
;
4369 struct node_active_region
*brange
= (struct node_active_region
*)b
;
4371 /* Done this way to avoid overflows */
4372 if (arange
->start_pfn
> brange
->start_pfn
)
4374 if (arange
->start_pfn
< brange
->start_pfn
)
4380 /* sort the node_map by start_pfn */
4381 void __init
sort_node_map(void)
4383 sort(early_node_map
, (size_t)nr_nodemap_entries
,
4384 sizeof(struct node_active_region
),
4385 cmp_node_active_region
, NULL
);
4388 /* Find the lowest pfn for a node */
4389 static unsigned long __init
find_min_pfn_for_node(int nid
)
4392 unsigned long min_pfn
= ULONG_MAX
;
4394 /* Assuming a sorted map, the first range found has the starting pfn */
4395 for_each_active_range_index_in_nid(i
, nid
)
4396 min_pfn
= min(min_pfn
, early_node_map
[i
].start_pfn
);
4398 if (min_pfn
== ULONG_MAX
) {
4400 "Could not find start_pfn for node %d\n", nid
);
4408 * find_min_pfn_with_active_regions - Find the minimum PFN registered
4410 * It returns the minimum PFN based on information provided via
4411 * add_active_range().
4413 unsigned long __init
find_min_pfn_with_active_regions(void)
4415 return find_min_pfn_for_node(MAX_NUMNODES
);
4419 * early_calculate_totalpages()
4420 * Sum pages in active regions for movable zone.
4421 * Populate N_HIGH_MEMORY for calculating usable_nodes.
4423 static unsigned long __init
early_calculate_totalpages(void)
4426 unsigned long totalpages
= 0;
4428 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
4429 unsigned long pages
= early_node_map
[i
].end_pfn
-
4430 early_node_map
[i
].start_pfn
;
4431 totalpages
+= pages
;
4433 node_set_state(early_node_map
[i
].nid
, N_HIGH_MEMORY
);
4439 * Find the PFN the Movable zone begins in each node. Kernel memory
4440 * is spread evenly between nodes as long as the nodes have enough
4441 * memory. When they don't, some nodes will have more kernelcore than
4444 static void __init
find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn
)
4447 unsigned long usable_startpfn
;
4448 unsigned long kernelcore_node
, kernelcore_remaining
;
4449 /* save the state before borrow the nodemask */
4450 nodemask_t saved_node_state
= node_states
[N_HIGH_MEMORY
];
4451 unsigned long totalpages
= early_calculate_totalpages();
4452 int usable_nodes
= nodes_weight(node_states
[N_HIGH_MEMORY
]);
4455 * If movablecore was specified, calculate what size of
4456 * kernelcore that corresponds so that memory usable for
4457 * any allocation type is evenly spread. If both kernelcore
4458 * and movablecore are specified, then the value of kernelcore
4459 * will be used for required_kernelcore if it's greater than
4460 * what movablecore would have allowed.
4462 if (required_movablecore
) {
4463 unsigned long corepages
;
4466 * Round-up so that ZONE_MOVABLE is at least as large as what
4467 * was requested by the user
4469 required_movablecore
=
4470 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
4471 corepages
= totalpages
- required_movablecore
;
4473 required_kernelcore
= max(required_kernelcore
, corepages
);
4476 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
4477 if (!required_kernelcore
)
4480 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
4481 find_usable_zone_for_movable();
4482 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
4485 /* Spread kernelcore memory as evenly as possible throughout nodes */
4486 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4487 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4489 * Recalculate kernelcore_node if the division per node
4490 * now exceeds what is necessary to satisfy the requested
4491 * amount of memory for the kernel
4493 if (required_kernelcore
< kernelcore_node
)
4494 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4497 * As the map is walked, we track how much memory is usable
4498 * by the kernel using kernelcore_remaining. When it is
4499 * 0, the rest of the node is usable by ZONE_MOVABLE
4501 kernelcore_remaining
= kernelcore_node
;
4503 /* Go through each range of PFNs within this node */
4504 for_each_active_range_index_in_nid(i
, nid
) {
4505 unsigned long start_pfn
, end_pfn
;
4506 unsigned long size_pages
;
4508 start_pfn
= max(early_node_map
[i
].start_pfn
,
4509 zone_movable_pfn
[nid
]);
4510 end_pfn
= early_node_map
[i
].end_pfn
;
4511 if (start_pfn
>= end_pfn
)
4514 /* Account for what is only usable for kernelcore */
4515 if (start_pfn
< usable_startpfn
) {
4516 unsigned long kernel_pages
;
4517 kernel_pages
= min(end_pfn
, usable_startpfn
)
4520 kernelcore_remaining
-= min(kernel_pages
,
4521 kernelcore_remaining
);
4522 required_kernelcore
-= min(kernel_pages
,
4523 required_kernelcore
);
4525 /* Continue if range is now fully accounted */
4526 if (end_pfn
<= usable_startpfn
) {
4529 * Push zone_movable_pfn to the end so
4530 * that if we have to rebalance
4531 * kernelcore across nodes, we will
4532 * not double account here
4534 zone_movable_pfn
[nid
] = end_pfn
;
4537 start_pfn
= usable_startpfn
;
4541 * The usable PFN range for ZONE_MOVABLE is from
4542 * start_pfn->end_pfn. Calculate size_pages as the
4543 * number of pages used as kernelcore
4545 size_pages
= end_pfn
- start_pfn
;
4546 if (size_pages
> kernelcore_remaining
)
4547 size_pages
= kernelcore_remaining
;
4548 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
4551 * Some kernelcore has been met, update counts and
4552 * break if the kernelcore for this node has been
4555 required_kernelcore
-= min(required_kernelcore
,
4557 kernelcore_remaining
-= size_pages
;
4558 if (!kernelcore_remaining
)
4564 * If there is still required_kernelcore, we do another pass with one
4565 * less node in the count. This will push zone_movable_pfn[nid] further
4566 * along on the nodes that still have memory until kernelcore is
4570 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
4573 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
4574 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
4575 zone_movable_pfn
[nid
] =
4576 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
4579 /* restore the node_state */
4580 node_states
[N_HIGH_MEMORY
] = saved_node_state
;
4583 /* Any regular memory on that node ? */
4584 static void check_for_regular_memory(pg_data_t
*pgdat
)
4586 #ifdef CONFIG_HIGHMEM
4587 enum zone_type zone_type
;
4589 for (zone_type
= 0; zone_type
<= ZONE_NORMAL
; zone_type
++) {
4590 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4591 if (zone
->present_pages
)
4592 node_set_state(zone_to_nid(zone
), N_NORMAL_MEMORY
);
4598 * free_area_init_nodes - Initialise all pg_data_t and zone data
4599 * @max_zone_pfn: an array of max PFNs for each zone
4601 * This will call free_area_init_node() for each active node in the system.
4602 * Using the page ranges provided by add_active_range(), the size of each
4603 * zone in each node and their holes is calculated. If the maximum PFN
4604 * between two adjacent zones match, it is assumed that the zone is empty.
4605 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
4606 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
4607 * starts where the previous one ended. For example, ZONE_DMA32 starts
4608 * at arch_max_dma_pfn.
4610 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
4615 /* Sort early_node_map as initialisation assumes it is sorted */
4618 /* Record where the zone boundaries are */
4619 memset(arch_zone_lowest_possible_pfn
, 0,
4620 sizeof(arch_zone_lowest_possible_pfn
));
4621 memset(arch_zone_highest_possible_pfn
, 0,
4622 sizeof(arch_zone_highest_possible_pfn
));
4623 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
4624 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
4625 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
4626 if (i
== ZONE_MOVABLE
)
4628 arch_zone_lowest_possible_pfn
[i
] =
4629 arch_zone_highest_possible_pfn
[i
-1];
4630 arch_zone_highest_possible_pfn
[i
] =
4631 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
4633 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
4634 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
4636 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
4637 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
4638 find_zone_movable_pfns_for_nodes(zone_movable_pfn
);
4640 /* Print out the zone ranges */
4641 printk("Zone PFN ranges:\n");
4642 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4643 if (i
== ZONE_MOVABLE
)
4645 printk(" %-8s ", zone_names
[i
]);
4646 if (arch_zone_lowest_possible_pfn
[i
] ==
4647 arch_zone_highest_possible_pfn
[i
])
4650 printk("%0#10lx -> %0#10lx\n",
4651 arch_zone_lowest_possible_pfn
[i
],
4652 arch_zone_highest_possible_pfn
[i
]);
4655 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
4656 printk("Movable zone start PFN for each node\n");
4657 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
4658 if (zone_movable_pfn
[i
])
4659 printk(" Node %d: %lu\n", i
, zone_movable_pfn
[i
]);
4662 /* Print out the early_node_map[] */
4663 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries
);
4664 for (i
= 0; i
< nr_nodemap_entries
; i
++)
4665 printk(" %3d: %0#10lx -> %0#10lx\n", early_node_map
[i
].nid
,
4666 early_node_map
[i
].start_pfn
,
4667 early_node_map
[i
].end_pfn
);
4669 /* Initialise every node */
4670 mminit_verify_pageflags_layout();
4671 setup_nr_node_ids();
4672 for_each_online_node(nid
) {
4673 pg_data_t
*pgdat
= NODE_DATA(nid
);
4674 free_area_init_node(nid
, NULL
,
4675 find_min_pfn_for_node(nid
), NULL
);
4677 /* Any memory on that node */
4678 if (pgdat
->node_present_pages
)
4679 node_set_state(nid
, N_HIGH_MEMORY
);
4680 check_for_regular_memory(pgdat
);
4684 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
4686 unsigned long long coremem
;
4690 coremem
= memparse(p
, &p
);
4691 *core
= coremem
>> PAGE_SHIFT
;
4693 /* Paranoid check that UL is enough for the coremem value */
4694 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
4700 * kernelcore=size sets the amount of memory for use for allocations that
4701 * cannot be reclaimed or migrated.
4703 static int __init
cmdline_parse_kernelcore(char *p
)
4705 return cmdline_parse_core(p
, &required_kernelcore
);
4709 * movablecore=size sets the amount of memory for use for allocations that
4710 * can be reclaimed or migrated.
4712 static int __init
cmdline_parse_movablecore(char *p
)
4714 return cmdline_parse_core(p
, &required_movablecore
);
4717 early_param("kernelcore", cmdline_parse_kernelcore
);
4718 early_param("movablecore", cmdline_parse_movablecore
);
4720 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
4723 * set_dma_reserve - set the specified number of pages reserved in the first zone
4724 * @new_dma_reserve: The number of pages to mark reserved
4726 * The per-cpu batchsize and zone watermarks are determined by present_pages.
4727 * In the DMA zone, a significant percentage may be consumed by kernel image
4728 * and other unfreeable allocations which can skew the watermarks badly. This
4729 * function may optionally be used to account for unfreeable pages in the
4730 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
4731 * smaller per-cpu batchsize.
4733 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
4735 dma_reserve
= new_dma_reserve
;
4738 #ifndef CONFIG_NEED_MULTIPLE_NODES
4739 struct pglist_data __refdata contig_page_data
= {
4740 #ifndef CONFIG_NO_BOOTMEM
4741 .bdata
= &bootmem_node_data
[0]
4744 EXPORT_SYMBOL(contig_page_data
);
4747 void __init
free_area_init(unsigned long *zones_size
)
4749 free_area_init_node(0, zones_size
,
4750 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
4753 static int page_alloc_cpu_notify(struct notifier_block
*self
,
4754 unsigned long action
, void *hcpu
)
4756 int cpu
= (unsigned long)hcpu
;
4758 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
4762 * Spill the event counters of the dead processor
4763 * into the current processors event counters.
4764 * This artificially elevates the count of the current
4767 vm_events_fold_cpu(cpu
);
4770 * Zero the differential counters of the dead processor
4771 * so that the vm statistics are consistent.
4773 * This is only okay since the processor is dead and cannot
4774 * race with what we are doing.
4776 refresh_cpu_vm_stats(cpu
);
4781 void __init
page_alloc_init(void)
4783 hotcpu_notifier(page_alloc_cpu_notify
, 0);
4787 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
4788 * or min_free_kbytes changes.
4790 static void calculate_totalreserve_pages(void)
4792 struct pglist_data
*pgdat
;
4793 unsigned long reserve_pages
= 0;
4794 enum zone_type i
, j
;
4796 for_each_online_pgdat(pgdat
) {
4797 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4798 struct zone
*zone
= pgdat
->node_zones
+ i
;
4799 unsigned long max
= 0;
4801 /* Find valid and maximum lowmem_reserve in the zone */
4802 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
4803 if (zone
->lowmem_reserve
[j
] > max
)
4804 max
= zone
->lowmem_reserve
[j
];
4807 /* we treat the high watermark as reserved pages. */
4808 max
+= high_wmark_pages(zone
);
4810 if (max
> zone
->present_pages
)
4811 max
= zone
->present_pages
;
4812 reserve_pages
+= max
;
4815 totalreserve_pages
= reserve_pages
;
4819 * setup_per_zone_lowmem_reserve - called whenever
4820 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
4821 * has a correct pages reserved value, so an adequate number of
4822 * pages are left in the zone after a successful __alloc_pages().
4824 static void setup_per_zone_lowmem_reserve(void)
4826 struct pglist_data
*pgdat
;
4827 enum zone_type j
, idx
;
4829 for_each_online_pgdat(pgdat
) {
4830 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4831 struct zone
*zone
= pgdat
->node_zones
+ j
;
4832 unsigned long present_pages
= zone
->present_pages
;
4834 zone
->lowmem_reserve
[j
] = 0;
4838 struct zone
*lower_zone
;
4842 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
4843 sysctl_lowmem_reserve_ratio
[idx
] = 1;
4845 lower_zone
= pgdat
->node_zones
+ idx
;
4846 lower_zone
->lowmem_reserve
[j
] = present_pages
/
4847 sysctl_lowmem_reserve_ratio
[idx
];
4848 present_pages
+= lower_zone
->present_pages
;
4853 /* update totalreserve_pages */
4854 calculate_totalreserve_pages();
4858 * setup_per_zone_wmarks - called when min_free_kbytes changes
4859 * or when memory is hot-{added|removed}
4861 * Ensures that the watermark[min,low,high] values for each zone are set
4862 * correctly with respect to min_free_kbytes.
4864 void setup_per_zone_wmarks(void)
4866 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
4867 unsigned long lowmem_pages
= 0;
4869 unsigned long flags
;
4871 /* Calculate total number of !ZONE_HIGHMEM pages */
4872 for_each_zone(zone
) {
4873 if (!is_highmem(zone
))
4874 lowmem_pages
+= zone
->present_pages
;
4877 for_each_zone(zone
) {
4880 spin_lock_irqsave(&zone
->lock
, flags
);
4881 tmp
= (u64
)pages_min
* zone
->present_pages
;
4882 do_div(tmp
, lowmem_pages
);
4883 if (is_highmem(zone
)) {
4885 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
4886 * need highmem pages, so cap pages_min to a small
4889 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
4890 * deltas controls asynch page reclaim, and so should
4891 * not be capped for highmem.
4895 min_pages
= zone
->present_pages
/ 1024;
4896 if (min_pages
< SWAP_CLUSTER_MAX
)
4897 min_pages
= SWAP_CLUSTER_MAX
;
4898 if (min_pages
> 128)
4900 zone
->watermark
[WMARK_MIN
] = min_pages
;
4903 * If it's a lowmem zone, reserve a number of pages
4904 * proportionate to the zone's size.
4906 zone
->watermark
[WMARK_MIN
] = tmp
;
4909 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + (tmp
>> 2);
4910 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + (tmp
>> 1);
4911 setup_zone_migrate_reserve(zone
);
4912 spin_unlock_irqrestore(&zone
->lock
, flags
);
4915 /* update totalreserve_pages */
4916 calculate_totalreserve_pages();
4920 * The inactive anon list should be small enough that the VM never has to
4921 * do too much work, but large enough that each inactive page has a chance
4922 * to be referenced again before it is swapped out.
4924 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
4925 * INACTIVE_ANON pages on this zone's LRU, maintained by the
4926 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
4927 * the anonymous pages are kept on the inactive list.
4930 * memory ratio inactive anon
4931 * -------------------------------------
4940 void calculate_zone_inactive_ratio(struct zone
*zone
)
4942 unsigned int gb
, ratio
;
4944 /* Zone size in gigabytes */
4945 gb
= zone
->present_pages
>> (30 - PAGE_SHIFT
);
4947 ratio
= int_sqrt(10 * gb
);
4951 zone
->inactive_ratio
= ratio
;
4954 static void __init
setup_per_zone_inactive_ratio(void)
4959 calculate_zone_inactive_ratio(zone
);
4963 * Initialise min_free_kbytes.
4965 * For small machines we want it small (128k min). For large machines
4966 * we want it large (64MB max). But it is not linear, because network
4967 * bandwidth does not increase linearly with machine size. We use
4969 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
4970 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
4986 static int __init
init_per_zone_wmark_min(void)
4988 unsigned long lowmem_kbytes
;
4990 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
4992 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
4993 if (min_free_kbytes
< 128)
4994 min_free_kbytes
= 128;
4995 if (min_free_kbytes
> 65536)
4996 min_free_kbytes
= 65536;
4997 setup_per_zone_wmarks();
4998 setup_per_zone_lowmem_reserve();
4999 setup_per_zone_inactive_ratio();
5002 module_init(init_per_zone_wmark_min
)
5005 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5006 * that we can call two helper functions whenever min_free_kbytes
5009 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
5010 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5012 proc_dointvec(table
, write
, buffer
, length
, ppos
);
5014 setup_per_zone_wmarks();
5019 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table
*table
, int write
,
5020 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5025 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5030 zone
->min_unmapped_pages
= (zone
->present_pages
*
5031 sysctl_min_unmapped_ratio
) / 100;
5035 int sysctl_min_slab_ratio_sysctl_handler(ctl_table
*table
, int write
,
5036 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5041 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5046 zone
->min_slab_pages
= (zone
->present_pages
*
5047 sysctl_min_slab_ratio
) / 100;
5053 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5054 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5055 * whenever sysctl_lowmem_reserve_ratio changes.
5057 * The reserve ratio obviously has absolutely no relation with the
5058 * minimum watermarks. The lowmem reserve ratio can only make sense
5059 * if in function of the boot time zone sizes.
5061 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
5062 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5064 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5065 setup_per_zone_lowmem_reserve();
5070 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5071 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
5072 * can have before it gets flushed back to buddy allocator.
5075 int percpu_pagelist_fraction_sysctl_handler(ctl_table
*table
, int write
,
5076 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5082 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5083 if (!write
|| (ret
== -EINVAL
))
5085 for_each_populated_zone(zone
) {
5086 for_each_possible_cpu(cpu
) {
5088 high
= zone
->present_pages
/ percpu_pagelist_fraction
;
5089 setup_pagelist_highmark(
5090 per_cpu_ptr(zone
->pageset
, cpu
), high
);
5096 int hashdist
= HASHDIST_DEFAULT
;
5099 static int __init
set_hashdist(char *str
)
5103 hashdist
= simple_strtoul(str
, &str
, 0);
5106 __setup("hashdist=", set_hashdist
);
5110 * allocate a large system hash table from bootmem
5111 * - it is assumed that the hash table must contain an exact power-of-2
5112 * quantity of entries
5113 * - limit is the number of hash buckets, not the total allocation size
5115 void *__init
alloc_large_system_hash(const char *tablename
,
5116 unsigned long bucketsize
,
5117 unsigned long numentries
,
5120 unsigned int *_hash_shift
,
5121 unsigned int *_hash_mask
,
5122 unsigned long limit
)
5124 unsigned long long max
= limit
;
5125 unsigned long log2qty
, size
;
5128 /* allow the kernel cmdline to have a say */
5130 /* round applicable memory size up to nearest megabyte */
5131 numentries
= nr_kernel_pages
;
5132 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
5133 numentries
>>= 20 - PAGE_SHIFT
;
5134 numentries
<<= 20 - PAGE_SHIFT
;
5136 /* limit to 1 bucket per 2^scale bytes of low memory */
5137 if (scale
> PAGE_SHIFT
)
5138 numentries
>>= (scale
- PAGE_SHIFT
);
5140 numentries
<<= (PAGE_SHIFT
- scale
);
5142 /* Make sure we've got at least a 0-order allocation.. */
5143 if (unlikely(flags
& HASH_SMALL
)) {
5144 /* Makes no sense without HASH_EARLY */
5145 WARN_ON(!(flags
& HASH_EARLY
));
5146 if (!(numentries
>> *_hash_shift
)) {
5147 numentries
= 1UL << *_hash_shift
;
5148 BUG_ON(!numentries
);
5150 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
5151 numentries
= PAGE_SIZE
/ bucketsize
;
5153 numentries
= roundup_pow_of_two(numentries
);
5155 /* limit allocation size to 1/16 total memory by default */
5157 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
5158 do_div(max
, bucketsize
);
5161 if (numentries
> max
)
5164 log2qty
= ilog2(numentries
);
5167 size
= bucketsize
<< log2qty
;
5168 if (flags
& HASH_EARLY
)
5169 table
= alloc_bootmem_nopanic(size
);
5171 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
5174 * If bucketsize is not a power-of-two, we may free
5175 * some pages at the end of hash table which
5176 * alloc_pages_exact() automatically does
5178 if (get_order(size
) < MAX_ORDER
) {
5179 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
5180 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
5183 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
5186 panic("Failed to allocate %s hash table\n", tablename
);
5188 printk(KERN_INFO
"%s hash table entries: %d (order: %d, %lu bytes)\n",
5191 ilog2(size
) - PAGE_SHIFT
,
5195 *_hash_shift
= log2qty
;
5197 *_hash_mask
= (1 << log2qty
) - 1;
5202 /* Return a pointer to the bitmap storing bits affecting a block of pages */
5203 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
5206 #ifdef CONFIG_SPARSEMEM
5207 return __pfn_to_section(pfn
)->pageblock_flags
;
5209 return zone
->pageblock_flags
;
5210 #endif /* CONFIG_SPARSEMEM */
5213 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
5215 #ifdef CONFIG_SPARSEMEM
5216 pfn
&= (PAGES_PER_SECTION
-1);
5217 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
5219 pfn
= pfn
- zone
->zone_start_pfn
;
5220 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
5221 #endif /* CONFIG_SPARSEMEM */
5225 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
5226 * @page: The page within the block of interest
5227 * @start_bitidx: The first bit of interest to retrieve
5228 * @end_bitidx: The last bit of interest
5229 * returns pageblock_bits flags
5231 unsigned long get_pageblock_flags_group(struct page
*page
,
5232 int start_bitidx
, int end_bitidx
)
5235 unsigned long *bitmap
;
5236 unsigned long pfn
, bitidx
;
5237 unsigned long flags
= 0;
5238 unsigned long value
= 1;
5240 zone
= page_zone(page
);
5241 pfn
= page_to_pfn(page
);
5242 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5243 bitidx
= pfn_to_bitidx(zone
, pfn
);
5245 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5246 if (test_bit(bitidx
+ start_bitidx
, bitmap
))
5253 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
5254 * @page: The page within the block of interest
5255 * @start_bitidx: The first bit of interest
5256 * @end_bitidx: The last bit of interest
5257 * @flags: The flags to set
5259 void set_pageblock_flags_group(struct page
*page
, unsigned long flags
,
5260 int start_bitidx
, int end_bitidx
)
5263 unsigned long *bitmap
;
5264 unsigned long pfn
, bitidx
;
5265 unsigned long value
= 1;
5267 zone
= page_zone(page
);
5268 pfn
= page_to_pfn(page
);
5269 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5270 bitidx
= pfn_to_bitidx(zone
, pfn
);
5271 VM_BUG_ON(pfn
< zone
->zone_start_pfn
);
5272 VM_BUG_ON(pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
);
5274 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5276 __set_bit(bitidx
+ start_bitidx
, bitmap
);
5278 __clear_bit(bitidx
+ start_bitidx
, bitmap
);
5282 * This is designed as sub function...plz see page_isolation.c also.
5283 * set/clear page block's type to be ISOLATE.
5284 * page allocater never alloc memory from ISOLATE block.
5287 int set_migratetype_isolate(struct page
*page
)
5290 struct page
*curr_page
;
5291 unsigned long flags
, pfn
, iter
;
5292 unsigned long immobile
= 0;
5293 struct memory_isolate_notify arg
;
5298 zone
= page_zone(page
);
5299 zone_idx
= zone_idx(zone
);
5301 spin_lock_irqsave(&zone
->lock
, flags
);
5302 if (get_pageblock_migratetype(page
) == MIGRATE_MOVABLE
||
5303 zone_idx
== ZONE_MOVABLE
) {
5308 pfn
= page_to_pfn(page
);
5309 arg
.start_pfn
= pfn
;
5310 arg
.nr_pages
= pageblock_nr_pages
;
5311 arg
.pages_found
= 0;
5314 * It may be possible to isolate a pageblock even if the
5315 * migratetype is not MIGRATE_MOVABLE. The memory isolation
5316 * notifier chain is used by balloon drivers to return the
5317 * number of pages in a range that are held by the balloon
5318 * driver to shrink memory. If all the pages are accounted for
5319 * by balloons, are free, or on the LRU, isolation can continue.
5320 * Later, for example, when memory hotplug notifier runs, these
5321 * pages reported as "can be isolated" should be isolated(freed)
5322 * by the balloon driver through the memory notifier chain.
5324 notifier_ret
= memory_isolate_notify(MEM_ISOLATE_COUNT
, &arg
);
5325 notifier_ret
= notifier_to_errno(notifier_ret
);
5326 if (notifier_ret
|| !arg
.pages_found
)
5329 for (iter
= pfn
; iter
< (pfn
+ pageblock_nr_pages
); iter
++) {
5330 if (!pfn_valid_within(pfn
))
5333 curr_page
= pfn_to_page(iter
);
5334 if (!page_count(curr_page
) || PageLRU(curr_page
))
5340 if (arg
.pages_found
== immobile
)
5345 set_pageblock_migratetype(page
, MIGRATE_ISOLATE
);
5346 move_freepages_block(zone
, page
, MIGRATE_ISOLATE
);
5349 spin_unlock_irqrestore(&zone
->lock
, flags
);
5355 void unset_migratetype_isolate(struct page
*page
)
5358 unsigned long flags
;
5359 zone
= page_zone(page
);
5360 spin_lock_irqsave(&zone
->lock
, flags
);
5361 if (get_pageblock_migratetype(page
) != MIGRATE_ISOLATE
)
5363 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
5364 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
5366 spin_unlock_irqrestore(&zone
->lock
, flags
);
5369 #ifdef CONFIG_MEMORY_HOTREMOVE
5371 * All pages in the range must be isolated before calling this.
5374 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
5380 unsigned long flags
;
5381 /* find the first valid pfn */
5382 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
5387 zone
= page_zone(pfn_to_page(pfn
));
5388 spin_lock_irqsave(&zone
->lock
, flags
);
5390 while (pfn
< end_pfn
) {
5391 if (!pfn_valid(pfn
)) {
5395 page
= pfn_to_page(pfn
);
5396 BUG_ON(page_count(page
));
5397 BUG_ON(!PageBuddy(page
));
5398 order
= page_order(page
);
5399 #ifdef CONFIG_DEBUG_VM
5400 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
5401 pfn
, 1 << order
, end_pfn
);
5403 list_del(&page
->lru
);
5404 rmv_page_order(page
);
5405 zone
->free_area
[order
].nr_free
--;
5406 __mod_zone_page_state(zone
, NR_FREE_PAGES
,
5408 for (i
= 0; i
< (1 << order
); i
++)
5409 SetPageReserved((page
+i
));
5410 pfn
+= (1 << order
);
5412 spin_unlock_irqrestore(&zone
->lock
, flags
);
5416 #ifdef CONFIG_MEMORY_FAILURE
5417 bool is_free_buddy_page(struct page
*page
)
5419 struct zone
*zone
= page_zone(page
);
5420 unsigned long pfn
= page_to_pfn(page
);
5421 unsigned long flags
;
5424 spin_lock_irqsave(&zone
->lock
, flags
);
5425 for (order
= 0; order
< MAX_ORDER
; order
++) {
5426 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
5428 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
5431 spin_unlock_irqrestore(&zone
->lock
, flags
);
5433 return order
< MAX_ORDER
;
5437 static struct trace_print_flags pageflag_names
[] = {
5438 {1UL << PG_locked
, "locked" },
5439 {1UL << PG_error
, "error" },
5440 {1UL << PG_referenced
, "referenced" },
5441 {1UL << PG_uptodate
, "uptodate" },
5442 {1UL << PG_dirty
, "dirty" },
5443 {1UL << PG_lru
, "lru" },
5444 {1UL << PG_active
, "active" },
5445 {1UL << PG_slab
, "slab" },
5446 {1UL << PG_owner_priv_1
, "owner_priv_1" },
5447 {1UL << PG_arch_1
, "arch_1" },
5448 {1UL << PG_reserved
, "reserved" },
5449 {1UL << PG_private
, "private" },
5450 {1UL << PG_private_2
, "private_2" },
5451 {1UL << PG_writeback
, "writeback" },
5452 #ifdef CONFIG_PAGEFLAGS_EXTENDED
5453 {1UL << PG_head
, "head" },
5454 {1UL << PG_tail
, "tail" },
5456 {1UL << PG_compound
, "compound" },
5458 {1UL << PG_swapcache
, "swapcache" },
5459 {1UL << PG_mappedtodisk
, "mappedtodisk" },
5460 {1UL << PG_reclaim
, "reclaim" },
5461 {1UL << PG_buddy
, "buddy" },
5462 {1UL << PG_swapbacked
, "swapbacked" },
5463 {1UL << PG_unevictable
, "unevictable" },
5465 {1UL << PG_mlocked
, "mlocked" },
5467 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
5468 {1UL << PG_uncached
, "uncached" },
5470 #ifdef CONFIG_MEMORY_FAILURE
5471 {1UL << PG_hwpoison
, "hwpoison" },
5476 static void dump_page_flags(unsigned long flags
)
5478 const char *delim
= "";
5482 printk(KERN_ALERT
"page flags: %#lx(", flags
);
5484 /* remove zone id */
5485 flags
&= (1UL << NR_PAGEFLAGS
) - 1;
5487 for (i
= 0; pageflag_names
[i
].name
&& flags
; i
++) {
5489 mask
= pageflag_names
[i
].mask
;
5490 if ((flags
& mask
) != mask
)
5494 printk("%s%s", delim
, pageflag_names
[i
].name
);
5498 /* check for left over flags */
5500 printk("%s%#lx", delim
, flags
);
5505 void dump_page(struct page
*page
)
5508 "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
5509 page
, page_count(page
), page_mapcount(page
),
5510 page
->mapping
, page
->index
);
5511 dump_page_flags(page
->flags
);