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
-2) && 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
)
594 spin_lock(&zone
->lock
);
595 zone
->all_unreclaimable
= 0;
596 zone
->pages_scanned
= 0;
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 (--to_free
&& --batch_free
&& !list_empty(list
));
625 __mod_zone_page_state(zone
, NR_FREE_PAGES
, count
);
626 spin_unlock(&zone
->lock
);
629 static void free_one_page(struct zone
*zone
, struct page
*page
, int order
,
632 spin_lock(&zone
->lock
);
633 zone
->all_unreclaimable
= 0;
634 zone
->pages_scanned
= 0;
636 __free_one_page(page
, zone
, order
, migratetype
);
637 __mod_zone_page_state(zone
, NR_FREE_PAGES
, 1 << order
);
638 spin_unlock(&zone
->lock
);
641 static bool free_pages_prepare(struct page
*page
, unsigned int order
)
646 trace_mm_page_free_direct(page
, order
);
647 kmemcheck_free_shadow(page
, order
);
649 for (i
= 0; i
< (1 << order
); i
++) {
650 struct page
*pg
= page
+ i
;
654 bad
+= free_pages_check(pg
);
659 if (!PageHighMem(page
)) {
660 debug_check_no_locks_freed(page_address(page
),PAGE_SIZE
<<order
);
661 debug_check_no_obj_freed(page_address(page
),
664 arch_free_page(page
, order
);
665 kernel_map_pages(page
, 1 << order
, 0);
670 static void __free_pages_ok(struct page
*page
, unsigned int order
)
673 int wasMlocked
= __TestClearPageMlocked(page
);
675 if (!free_pages_prepare(page
, order
))
678 local_irq_save(flags
);
679 if (unlikely(wasMlocked
))
680 free_page_mlock(page
);
681 __count_vm_events(PGFREE
, 1 << order
);
682 free_one_page(page_zone(page
), page
, order
,
683 get_pageblock_migratetype(page
));
684 local_irq_restore(flags
);
688 * permit the bootmem allocator to evade page validation on high-order frees
690 void __meminit
__free_pages_bootmem(struct page
*page
, unsigned int order
)
693 __ClearPageReserved(page
);
694 set_page_count(page
, 0);
695 set_page_refcounted(page
);
701 for (loop
= 0; loop
< BITS_PER_LONG
; loop
++) {
702 struct page
*p
= &page
[loop
];
704 if (loop
+ 1 < BITS_PER_LONG
)
706 __ClearPageReserved(p
);
707 set_page_count(p
, 0);
710 set_page_refcounted(page
);
711 __free_pages(page
, order
);
717 * The order of subdivision here is critical for the IO subsystem.
718 * Please do not alter this order without good reasons and regression
719 * testing. Specifically, as large blocks of memory are subdivided,
720 * the order in which smaller blocks are delivered depends on the order
721 * they're subdivided in this function. This is the primary factor
722 * influencing the order in which pages are delivered to the IO
723 * subsystem according to empirical testing, and this is also justified
724 * by considering the behavior of a buddy system containing a single
725 * large block of memory acted on by a series of small allocations.
726 * This behavior is a critical factor in sglist merging's success.
730 static inline void expand(struct zone
*zone
, struct page
*page
,
731 int low
, int high
, struct free_area
*area
,
734 unsigned long size
= 1 << high
;
740 VM_BUG_ON(bad_range(zone
, &page
[size
]));
741 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
743 set_page_order(&page
[size
], high
);
748 * This page is about to be returned from the page allocator
750 static inline int check_new_page(struct page
*page
)
752 if (unlikely(page_mapcount(page
) |
753 (page
->mapping
!= NULL
) |
754 (atomic_read(&page
->_count
) != 0) |
755 (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
))) {
762 static int prep_new_page(struct page
*page
, int order
, gfp_t gfp_flags
)
766 for (i
= 0; i
< (1 << order
); i
++) {
767 struct page
*p
= page
+ i
;
768 if (unlikely(check_new_page(p
)))
772 set_page_private(page
, 0);
773 set_page_refcounted(page
);
775 arch_alloc_page(page
, order
);
776 kernel_map_pages(page
, 1 << order
, 1);
778 if (gfp_flags
& __GFP_ZERO
)
779 prep_zero_page(page
, order
, gfp_flags
);
781 if (order
&& (gfp_flags
& __GFP_COMP
))
782 prep_compound_page(page
, order
);
788 * Go through the free lists for the given migratetype and remove
789 * the smallest available page from the freelists
792 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
795 unsigned int current_order
;
796 struct free_area
* area
;
799 /* Find a page of the appropriate size in the preferred list */
800 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
801 area
= &(zone
->free_area
[current_order
]);
802 if (list_empty(&area
->free_list
[migratetype
]))
805 page
= list_entry(area
->free_list
[migratetype
].next
,
807 list_del(&page
->lru
);
808 rmv_page_order(page
);
810 expand(zone
, page
, order
, current_order
, area
, migratetype
);
819 * This array describes the order lists are fallen back to when
820 * the free lists for the desirable migrate type are depleted
822 static int fallbacks
[MIGRATE_TYPES
][MIGRATE_TYPES
-1] = {
823 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
824 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
825 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
826 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
, MIGRATE_RESERVE
, MIGRATE_RESERVE
}, /* Never used */
830 * Move the free pages in a range to the free lists of the requested type.
831 * Note that start_page and end_pages are not aligned on a pageblock
832 * boundary. If alignment is required, use move_freepages_block()
834 static int move_freepages(struct zone
*zone
,
835 struct page
*start_page
, struct page
*end_page
,
842 #ifndef CONFIG_HOLES_IN_ZONE
844 * page_zone is not safe to call in this context when
845 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
846 * anyway as we check zone boundaries in move_freepages_block().
847 * Remove at a later date when no bug reports exist related to
848 * grouping pages by mobility
850 BUG_ON(page_zone(start_page
) != page_zone(end_page
));
853 for (page
= start_page
; page
<= end_page
;) {
854 /* Make sure we are not inadvertently changing nodes */
855 VM_BUG_ON(page_to_nid(page
) != zone_to_nid(zone
));
857 if (!pfn_valid_within(page_to_pfn(page
))) {
862 if (!PageBuddy(page
)) {
867 order
= page_order(page
);
868 list_del(&page
->lru
);
870 &zone
->free_area
[order
].free_list
[migratetype
]);
872 pages_moved
+= 1 << order
;
878 static int move_freepages_block(struct zone
*zone
, struct page
*page
,
881 unsigned long start_pfn
, end_pfn
;
882 struct page
*start_page
, *end_page
;
884 start_pfn
= page_to_pfn(page
);
885 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
886 start_page
= pfn_to_page(start_pfn
);
887 end_page
= start_page
+ pageblock_nr_pages
- 1;
888 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
890 /* Do not cross zone boundaries */
891 if (start_pfn
< zone
->zone_start_pfn
)
893 if (end_pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
896 return move_freepages(zone
, start_page
, end_page
, migratetype
);
899 static void change_pageblock_range(struct page
*pageblock_page
,
900 int start_order
, int migratetype
)
902 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
904 while (nr_pageblocks
--) {
905 set_pageblock_migratetype(pageblock_page
, migratetype
);
906 pageblock_page
+= pageblock_nr_pages
;
910 /* Remove an element from the buddy allocator from the fallback list */
911 static inline struct page
*
912 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
)
914 struct free_area
* area
;
919 /* Find the largest possible block of pages in the other list */
920 for (current_order
= MAX_ORDER
-1; current_order
>= order
;
922 for (i
= 0; i
< MIGRATE_TYPES
- 1; i
++) {
923 migratetype
= fallbacks
[start_migratetype
][i
];
925 /* MIGRATE_RESERVE handled later if necessary */
926 if (migratetype
== MIGRATE_RESERVE
)
929 area
= &(zone
->free_area
[current_order
]);
930 if (list_empty(&area
->free_list
[migratetype
]))
933 page
= list_entry(area
->free_list
[migratetype
].next
,
938 * If breaking a large block of pages, move all free
939 * pages to the preferred allocation list. If falling
940 * back for a reclaimable kernel allocation, be more
941 * agressive about taking ownership of free pages
943 if (unlikely(current_order
>= (pageblock_order
>> 1)) ||
944 start_migratetype
== MIGRATE_RECLAIMABLE
||
945 page_group_by_mobility_disabled
) {
947 pages
= move_freepages_block(zone
, page
,
950 /* Claim the whole block if over half of it is free */
951 if (pages
>= (1 << (pageblock_order
-1)) ||
952 page_group_by_mobility_disabled
)
953 set_pageblock_migratetype(page
,
956 migratetype
= start_migratetype
;
959 /* Remove the page from the freelists */
960 list_del(&page
->lru
);
961 rmv_page_order(page
);
963 /* Take ownership for orders >= pageblock_order */
964 if (current_order
>= pageblock_order
)
965 change_pageblock_range(page
, current_order
,
968 expand(zone
, page
, order
, current_order
, area
, migratetype
);
970 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
971 start_migratetype
, migratetype
);
981 * Do the hard work of removing an element from the buddy allocator.
982 * Call me with the zone->lock already held.
984 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
990 page
= __rmqueue_smallest(zone
, order
, migratetype
);
992 if (unlikely(!page
) && migratetype
!= MIGRATE_RESERVE
) {
993 page
= __rmqueue_fallback(zone
, order
, migratetype
);
996 * Use MIGRATE_RESERVE rather than fail an allocation. goto
997 * is used because __rmqueue_smallest is an inline function
998 * and we want just one call site
1001 migratetype
= MIGRATE_RESERVE
;
1006 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
1011 * Obtain a specified number of elements from the buddy allocator, all under
1012 * a single hold of the lock, for efficiency. Add them to the supplied list.
1013 * Returns the number of new pages which were placed at *list.
1015 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
1016 unsigned long count
, struct list_head
*list
,
1017 int migratetype
, int cold
)
1021 spin_lock(&zone
->lock
);
1022 for (i
= 0; i
< count
; ++i
) {
1023 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
1024 if (unlikely(page
== NULL
))
1028 * Split buddy pages returned by expand() are received here
1029 * in physical page order. The page is added to the callers and
1030 * list and the list head then moves forward. From the callers
1031 * perspective, the linked list is ordered by page number in
1032 * some conditions. This is useful for IO devices that can
1033 * merge IO requests if the physical pages are ordered
1036 if (likely(cold
== 0))
1037 list_add(&page
->lru
, list
);
1039 list_add_tail(&page
->lru
, list
);
1040 set_page_private(page
, migratetype
);
1043 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
1044 spin_unlock(&zone
->lock
);
1050 * Called from the vmstat counter updater to drain pagesets of this
1051 * currently executing processor on remote nodes after they have
1054 * Note that this function must be called with the thread pinned to
1055 * a single processor.
1057 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
1059 unsigned long flags
;
1062 local_irq_save(flags
);
1063 if (pcp
->count
>= pcp
->batch
)
1064 to_drain
= pcp
->batch
;
1066 to_drain
= pcp
->count
;
1067 free_pcppages_bulk(zone
, to_drain
, pcp
);
1068 pcp
->count
-= to_drain
;
1069 local_irq_restore(flags
);
1074 * Drain pages of the indicated processor.
1076 * The processor must either be the current processor and the
1077 * thread pinned to the current processor or a processor that
1080 static void drain_pages(unsigned int cpu
)
1082 unsigned long flags
;
1085 for_each_populated_zone(zone
) {
1086 struct per_cpu_pageset
*pset
;
1087 struct per_cpu_pages
*pcp
;
1089 local_irq_save(flags
);
1090 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
1093 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
1095 local_irq_restore(flags
);
1100 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1102 void drain_local_pages(void *arg
)
1104 drain_pages(smp_processor_id());
1108 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
1110 void drain_all_pages(void)
1112 on_each_cpu(drain_local_pages
, NULL
, 1);
1115 #ifdef CONFIG_HIBERNATION
1117 void mark_free_pages(struct zone
*zone
)
1119 unsigned long pfn
, max_zone_pfn
;
1120 unsigned long flags
;
1122 struct list_head
*curr
;
1124 if (!zone
->spanned_pages
)
1127 spin_lock_irqsave(&zone
->lock
, flags
);
1129 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
1130 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1131 if (pfn_valid(pfn
)) {
1132 struct page
*page
= pfn_to_page(pfn
);
1134 if (!swsusp_page_is_forbidden(page
))
1135 swsusp_unset_page_free(page
);
1138 for_each_migratetype_order(order
, t
) {
1139 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
1142 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
1143 for (i
= 0; i
< (1UL << order
); i
++)
1144 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
1147 spin_unlock_irqrestore(&zone
->lock
, flags
);
1149 #endif /* CONFIG_PM */
1152 * Free a 0-order page
1153 * cold == 1 ? free a cold page : free a hot page
1155 void free_hot_cold_page(struct page
*page
, int cold
)
1157 struct zone
*zone
= page_zone(page
);
1158 struct per_cpu_pages
*pcp
;
1159 unsigned long flags
;
1161 int wasMlocked
= __TestClearPageMlocked(page
);
1163 if (!free_pages_prepare(page
, 0))
1166 migratetype
= get_pageblock_migratetype(page
);
1167 set_page_private(page
, migratetype
);
1168 local_irq_save(flags
);
1169 if (unlikely(wasMlocked
))
1170 free_page_mlock(page
);
1171 __count_vm_event(PGFREE
);
1174 * We only track unmovable, reclaimable and movable on pcp lists.
1175 * Free ISOLATE pages back to the allocator because they are being
1176 * offlined but treat RESERVE as movable pages so we can get those
1177 * areas back if necessary. Otherwise, we may have to free
1178 * excessively into the page allocator
1180 if (migratetype
>= MIGRATE_PCPTYPES
) {
1181 if (unlikely(migratetype
== MIGRATE_ISOLATE
)) {
1182 free_one_page(zone
, page
, 0, migratetype
);
1185 migratetype
= MIGRATE_MOVABLE
;
1188 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1190 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
1192 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
1194 if (pcp
->count
>= pcp
->high
) {
1195 free_pcppages_bulk(zone
, pcp
->batch
, pcp
);
1196 pcp
->count
-= pcp
->batch
;
1200 local_irq_restore(flags
);
1204 * split_page takes a non-compound higher-order page, and splits it into
1205 * n (1<<order) sub-pages: page[0..n]
1206 * Each sub-page must be freed individually.
1208 * Note: this is probably too low level an operation for use in drivers.
1209 * Please consult with lkml before using this in your driver.
1211 void split_page(struct page
*page
, unsigned int order
)
1215 VM_BUG_ON(PageCompound(page
));
1216 VM_BUG_ON(!page_count(page
));
1218 #ifdef CONFIG_KMEMCHECK
1220 * Split shadow pages too, because free(page[0]) would
1221 * otherwise free the whole shadow.
1223 if (kmemcheck_page_is_tracked(page
))
1224 split_page(virt_to_page(page
[0].shadow
), order
);
1227 for (i
= 1; i
< (1 << order
); i
++)
1228 set_page_refcounted(page
+ i
);
1232 * Similar to split_page except the page is already free. As this is only
1233 * being used for migration, the migratetype of the block also changes.
1234 * As this is called with interrupts disabled, the caller is responsible
1235 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1238 * Note: this is probably too low level an operation for use in drivers.
1239 * Please consult with lkml before using this in your driver.
1241 int split_free_page(struct page
*page
)
1244 unsigned long watermark
;
1247 BUG_ON(!PageBuddy(page
));
1249 zone
= page_zone(page
);
1250 order
= page_order(page
);
1252 /* Obey watermarks as if the page was being allocated */
1253 watermark
= low_wmark_pages(zone
) + (1 << order
);
1254 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
1257 /* Remove page from free list */
1258 list_del(&page
->lru
);
1259 zone
->free_area
[order
].nr_free
--;
1260 rmv_page_order(page
);
1261 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(1UL << order
));
1263 /* Split into individual pages */
1264 set_page_refcounted(page
);
1265 split_page(page
, order
);
1267 if (order
>= pageblock_order
- 1) {
1268 struct page
*endpage
= page
+ (1 << order
) - 1;
1269 for (; page
< endpage
; page
+= pageblock_nr_pages
)
1270 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1277 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1278 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1282 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
1283 struct zone
*zone
, int order
, gfp_t gfp_flags
,
1286 unsigned long flags
;
1288 int cold
= !!(gfp_flags
& __GFP_COLD
);
1291 if (likely(order
== 0)) {
1292 struct per_cpu_pages
*pcp
;
1293 struct list_head
*list
;
1295 local_irq_save(flags
);
1296 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1297 list
= &pcp
->lists
[migratetype
];
1298 if (list_empty(list
)) {
1299 pcp
->count
+= rmqueue_bulk(zone
, 0,
1302 if (unlikely(list_empty(list
)))
1307 page
= list_entry(list
->prev
, struct page
, lru
);
1309 page
= list_entry(list
->next
, struct page
, lru
);
1311 list_del(&page
->lru
);
1314 if (unlikely(gfp_flags
& __GFP_NOFAIL
)) {
1316 * __GFP_NOFAIL is not to be used in new code.
1318 * All __GFP_NOFAIL callers should be fixed so that they
1319 * properly detect and handle allocation failures.
1321 * We most definitely don't want callers attempting to
1322 * allocate greater than order-1 page units with
1325 WARN_ON_ONCE(order
> 1);
1327 spin_lock_irqsave(&zone
->lock
, flags
);
1328 page
= __rmqueue(zone
, order
, migratetype
);
1329 spin_unlock(&zone
->lock
);
1332 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(1 << order
));
1335 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
1336 zone_statistics(preferred_zone
, zone
);
1337 local_irq_restore(flags
);
1339 VM_BUG_ON(bad_range(zone
, page
));
1340 if (prep_new_page(page
, order
, gfp_flags
))
1345 local_irq_restore(flags
);
1349 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
1350 #define ALLOC_WMARK_MIN WMARK_MIN
1351 #define ALLOC_WMARK_LOW WMARK_LOW
1352 #define ALLOC_WMARK_HIGH WMARK_HIGH
1353 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
1355 /* Mask to get the watermark bits */
1356 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
1358 #define ALLOC_HARDER 0x10 /* try to alloc harder */
1359 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
1360 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
1362 #ifdef CONFIG_FAIL_PAGE_ALLOC
1364 static struct fail_page_alloc_attr
{
1365 struct fault_attr attr
;
1367 u32 ignore_gfp_highmem
;
1368 u32 ignore_gfp_wait
;
1371 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1373 struct dentry
*ignore_gfp_highmem_file
;
1374 struct dentry
*ignore_gfp_wait_file
;
1375 struct dentry
*min_order_file
;
1377 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1379 } fail_page_alloc
= {
1380 .attr
= FAULT_ATTR_INITIALIZER
,
1381 .ignore_gfp_wait
= 1,
1382 .ignore_gfp_highmem
= 1,
1386 static int __init
setup_fail_page_alloc(char *str
)
1388 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
1390 __setup("fail_page_alloc=", setup_fail_page_alloc
);
1392 static int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1394 if (order
< fail_page_alloc
.min_order
)
1396 if (gfp_mask
& __GFP_NOFAIL
)
1398 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
1400 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
1403 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
1406 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1408 static int __init
fail_page_alloc_debugfs(void)
1410 mode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
1414 err
= init_fault_attr_dentries(&fail_page_alloc
.attr
,
1418 dir
= fail_page_alloc
.attr
.dentries
.dir
;
1420 fail_page_alloc
.ignore_gfp_wait_file
=
1421 debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
1422 &fail_page_alloc
.ignore_gfp_wait
);
1424 fail_page_alloc
.ignore_gfp_highmem_file
=
1425 debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
1426 &fail_page_alloc
.ignore_gfp_highmem
);
1427 fail_page_alloc
.min_order_file
=
1428 debugfs_create_u32("min-order", mode
, dir
,
1429 &fail_page_alloc
.min_order
);
1431 if (!fail_page_alloc
.ignore_gfp_wait_file
||
1432 !fail_page_alloc
.ignore_gfp_highmem_file
||
1433 !fail_page_alloc
.min_order_file
) {
1435 debugfs_remove(fail_page_alloc
.ignore_gfp_wait_file
);
1436 debugfs_remove(fail_page_alloc
.ignore_gfp_highmem_file
);
1437 debugfs_remove(fail_page_alloc
.min_order_file
);
1438 cleanup_fault_attr_dentries(&fail_page_alloc
.attr
);
1444 late_initcall(fail_page_alloc_debugfs
);
1446 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1448 #else /* CONFIG_FAIL_PAGE_ALLOC */
1450 static inline int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1455 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1458 * Return 1 if free pages are above 'mark'. This takes into account the order
1459 * of the allocation.
1461 int zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1462 int classzone_idx
, int alloc_flags
)
1464 /* free_pages my go negative - that's OK */
1466 long free_pages
= zone_nr_free_pages(z
) - (1 << order
) + 1;
1469 if (alloc_flags
& ALLOC_HIGH
)
1471 if (alloc_flags
& ALLOC_HARDER
)
1474 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
1476 for (o
= 0; o
< order
; o
++) {
1477 /* At the next order, this order's pages become unavailable */
1478 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
1480 /* Require fewer higher order pages to be free */
1483 if (free_pages
<= min
)
1491 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1492 * skip over zones that are not allowed by the cpuset, or that have
1493 * been recently (in last second) found to be nearly full. See further
1494 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1495 * that have to skip over a lot of full or unallowed zones.
1497 * If the zonelist cache is present in the passed in zonelist, then
1498 * returns a pointer to the allowed node mask (either the current
1499 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1501 * If the zonelist cache is not available for this zonelist, does
1502 * nothing and returns NULL.
1504 * If the fullzones BITMAP in the zonelist cache is stale (more than
1505 * a second since last zap'd) then we zap it out (clear its bits.)
1507 * We hold off even calling zlc_setup, until after we've checked the
1508 * first zone in the zonelist, on the theory that most allocations will
1509 * be satisfied from that first zone, so best to examine that zone as
1510 * quickly as we can.
1512 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1514 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1515 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
1517 zlc
= zonelist
->zlcache_ptr
;
1521 if (time_after(jiffies
, zlc
->last_full_zap
+ HZ
)) {
1522 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1523 zlc
->last_full_zap
= jiffies
;
1526 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
1527 &cpuset_current_mems_allowed
:
1528 &node_states
[N_HIGH_MEMORY
];
1529 return allowednodes
;
1533 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1534 * if it is worth looking at further for free memory:
1535 * 1) Check that the zone isn't thought to be full (doesn't have its
1536 * bit set in the zonelist_cache fullzones BITMAP).
1537 * 2) Check that the zones node (obtained from the zonelist_cache
1538 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1539 * Return true (non-zero) if zone is worth looking at further, or
1540 * else return false (zero) if it is not.
1542 * This check -ignores- the distinction between various watermarks,
1543 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1544 * found to be full for any variation of these watermarks, it will
1545 * be considered full for up to one second by all requests, unless
1546 * we are so low on memory on all allowed nodes that we are forced
1547 * into the second scan of the zonelist.
1549 * In the second scan we ignore this zonelist cache and exactly
1550 * apply the watermarks to all zones, even it is slower to do so.
1551 * We are low on memory in the second scan, and should leave no stone
1552 * unturned looking for a free page.
1554 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1555 nodemask_t
*allowednodes
)
1557 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1558 int i
; /* index of *z in zonelist zones */
1559 int n
; /* node that zone *z is on */
1561 zlc
= zonelist
->zlcache_ptr
;
1565 i
= z
- zonelist
->_zonerefs
;
1568 /* This zone is worth trying if it is allowed but not full */
1569 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1573 * Given 'z' scanning a zonelist, set the corresponding bit in
1574 * zlc->fullzones, so that subsequent attempts to allocate a page
1575 * from that zone don't waste time re-examining it.
1577 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1579 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1580 int i
; /* index of *z in zonelist zones */
1582 zlc
= zonelist
->zlcache_ptr
;
1586 i
= z
- zonelist
->_zonerefs
;
1588 set_bit(i
, zlc
->fullzones
);
1591 #else /* CONFIG_NUMA */
1593 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1598 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1599 nodemask_t
*allowednodes
)
1604 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1607 #endif /* CONFIG_NUMA */
1610 * get_page_from_freelist goes through the zonelist trying to allocate
1613 static struct page
*
1614 get_page_from_freelist(gfp_t gfp_mask
, nodemask_t
*nodemask
, unsigned int order
,
1615 struct zonelist
*zonelist
, int high_zoneidx
, int alloc_flags
,
1616 struct zone
*preferred_zone
, int migratetype
)
1619 struct page
*page
= NULL
;
1622 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
1623 int zlc_active
= 0; /* set if using zonelist_cache */
1624 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
1626 classzone_idx
= zone_idx(preferred_zone
);
1629 * Scan zonelist, looking for a zone with enough free.
1630 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1632 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
1633 high_zoneidx
, nodemask
) {
1634 if (NUMA_BUILD
&& zlc_active
&&
1635 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1637 if ((alloc_flags
& ALLOC_CPUSET
) &&
1638 !cpuset_zone_allowed_softwall(zone
, gfp_mask
))
1641 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
1642 if (!(alloc_flags
& ALLOC_NO_WATERMARKS
)) {
1646 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
1647 if (zone_watermark_ok(zone
, order
, mark
,
1648 classzone_idx
, alloc_flags
))
1651 if (zone_reclaim_mode
== 0)
1652 goto this_zone_full
;
1654 ret
= zone_reclaim(zone
, gfp_mask
, order
);
1656 case ZONE_RECLAIM_NOSCAN
:
1659 case ZONE_RECLAIM_FULL
:
1660 /* scanned but unreclaimable */
1661 goto this_zone_full
;
1663 /* did we reclaim enough */
1664 if (!zone_watermark_ok(zone
, order
, mark
,
1665 classzone_idx
, alloc_flags
))
1666 goto this_zone_full
;
1671 page
= buffered_rmqueue(preferred_zone
, zone
, order
,
1672 gfp_mask
, migratetype
);
1677 zlc_mark_zone_full(zonelist
, z
);
1679 if (NUMA_BUILD
&& !did_zlc_setup
&& nr_online_nodes
> 1) {
1681 * we do zlc_setup after the first zone is tried but only
1682 * if there are multiple nodes make it worthwhile
1684 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
1690 if (unlikely(NUMA_BUILD
&& page
== NULL
&& zlc_active
)) {
1691 /* Disable zlc cache for second zonelist scan */
1699 should_alloc_retry(gfp_t gfp_mask
, unsigned int order
,
1700 unsigned long pages_reclaimed
)
1702 /* Do not loop if specifically requested */
1703 if (gfp_mask
& __GFP_NORETRY
)
1707 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
1708 * means __GFP_NOFAIL, but that may not be true in other
1711 if (order
<= PAGE_ALLOC_COSTLY_ORDER
)
1715 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
1716 * specified, then we retry until we no longer reclaim any pages
1717 * (above), or we've reclaimed an order of pages at least as
1718 * large as the allocation's order. In both cases, if the
1719 * allocation still fails, we stop retrying.
1721 if (gfp_mask
& __GFP_REPEAT
&& pages_reclaimed
< (1 << order
))
1725 * Don't let big-order allocations loop unless the caller
1726 * explicitly requests that.
1728 if (gfp_mask
& __GFP_NOFAIL
)
1734 static inline struct page
*
1735 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
1736 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1737 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
1742 /* Acquire the OOM killer lock for the zones in zonelist */
1743 if (!try_set_zonelist_oom(zonelist
, gfp_mask
)) {
1744 schedule_timeout_uninterruptible(1);
1749 * Go through the zonelist yet one more time, keep very high watermark
1750 * here, this is only to catch a parallel oom killing, we must fail if
1751 * we're still under heavy pressure.
1753 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
,
1754 order
, zonelist
, high_zoneidx
,
1755 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
,
1756 preferred_zone
, migratetype
);
1760 if (!(gfp_mask
& __GFP_NOFAIL
)) {
1761 /* The OOM killer will not help higher order allocs */
1762 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
1764 /* The OOM killer does not needlessly kill tasks for lowmem */
1765 if (high_zoneidx
< ZONE_NORMAL
)
1768 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
1769 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
1770 * The caller should handle page allocation failure by itself if
1771 * it specifies __GFP_THISNODE.
1772 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
1774 if (gfp_mask
& __GFP_THISNODE
)
1777 /* Exhausted what can be done so it's blamo time */
1778 out_of_memory(zonelist
, gfp_mask
, order
, nodemask
);
1781 clear_zonelist_oom(zonelist
, gfp_mask
);
1785 #ifdef CONFIG_COMPACTION
1786 /* Try memory compaction for high-order allocations before reclaim */
1787 static struct page
*
1788 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
1789 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1790 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
1791 int migratetype
, unsigned long *did_some_progress
)
1795 if (!order
|| compaction_deferred(preferred_zone
))
1798 *did_some_progress
= try_to_compact_pages(zonelist
, order
, gfp_mask
,
1800 if (*did_some_progress
!= COMPACT_SKIPPED
) {
1802 /* Page migration frees to the PCP lists but we want merging */
1803 drain_pages(get_cpu());
1806 page
= get_page_from_freelist(gfp_mask
, nodemask
,
1807 order
, zonelist
, high_zoneidx
,
1808 alloc_flags
, preferred_zone
,
1811 preferred_zone
->compact_considered
= 0;
1812 preferred_zone
->compact_defer_shift
= 0;
1813 count_vm_event(COMPACTSUCCESS
);
1818 * It's bad if compaction run occurs and fails.
1819 * The most likely reason is that pages exist,
1820 * but not enough to satisfy watermarks.
1822 count_vm_event(COMPACTFAIL
);
1823 defer_compaction(preferred_zone
);
1831 static inline struct page
*
1832 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
1833 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1834 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
1835 int migratetype
, unsigned long *did_some_progress
)
1839 #endif /* CONFIG_COMPACTION */
1841 /* The really slow allocator path where we enter direct reclaim */
1842 static inline struct page
*
1843 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
1844 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1845 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
1846 int migratetype
, unsigned long *did_some_progress
)
1848 struct page
*page
= NULL
;
1849 struct reclaim_state reclaim_state
;
1850 struct task_struct
*p
= current
;
1851 bool drained
= false;
1855 /* We now go into synchronous reclaim */
1856 cpuset_memory_pressure_bump();
1857 p
->flags
|= PF_MEMALLOC
;
1858 lockdep_set_current_reclaim_state(gfp_mask
);
1859 reclaim_state
.reclaimed_slab
= 0;
1860 p
->reclaim_state
= &reclaim_state
;
1862 *did_some_progress
= try_to_free_pages(zonelist
, order
, gfp_mask
, nodemask
);
1864 p
->reclaim_state
= NULL
;
1865 lockdep_clear_current_reclaim_state();
1866 p
->flags
&= ~PF_MEMALLOC
;
1870 if (unlikely(!(*did_some_progress
)))
1874 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
1875 zonelist
, high_zoneidx
,
1876 alloc_flags
, preferred_zone
,
1880 * If an allocation failed after direct reclaim, it could be because
1881 * pages are pinned on the per-cpu lists. Drain them and try again
1883 if (!page
&& !drained
) {
1893 * This is called in the allocator slow-path if the allocation request is of
1894 * sufficient urgency to ignore watermarks and take other desperate measures
1896 static inline struct page
*
1897 __alloc_pages_high_priority(gfp_t gfp_mask
, unsigned int order
,
1898 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1899 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
1905 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
1906 zonelist
, high_zoneidx
, ALLOC_NO_WATERMARKS
,
1907 preferred_zone
, migratetype
);
1909 if (!page
&& gfp_mask
& __GFP_NOFAIL
)
1910 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
1911 } while (!page
&& (gfp_mask
& __GFP_NOFAIL
));
1917 void wake_all_kswapd(unsigned int order
, struct zonelist
*zonelist
,
1918 enum zone_type high_zoneidx
)
1923 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
)
1924 wakeup_kswapd(zone
, order
);
1928 gfp_to_alloc_flags(gfp_t gfp_mask
)
1930 struct task_struct
*p
= current
;
1931 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
1932 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
1934 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
1935 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
1938 * The caller may dip into page reserves a bit more if the caller
1939 * cannot run direct reclaim, or if the caller has realtime scheduling
1940 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
1941 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1943 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
1946 alloc_flags
|= ALLOC_HARDER
;
1948 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1949 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1951 alloc_flags
&= ~ALLOC_CPUSET
;
1952 } else if (unlikely(rt_task(p
)) && !in_interrupt())
1953 alloc_flags
|= ALLOC_HARDER
;
1955 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
1956 if (!in_interrupt() &&
1957 ((p
->flags
& PF_MEMALLOC
) ||
1958 unlikely(test_thread_flag(TIF_MEMDIE
))))
1959 alloc_flags
|= ALLOC_NO_WATERMARKS
;
1965 static inline struct page
*
1966 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
1967 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1968 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
1971 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
1972 struct page
*page
= NULL
;
1974 unsigned long pages_reclaimed
= 0;
1975 unsigned long did_some_progress
;
1976 struct task_struct
*p
= current
;
1979 * In the slowpath, we sanity check order to avoid ever trying to
1980 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
1981 * be using allocators in order of preference for an area that is
1984 if (order
>= MAX_ORDER
) {
1985 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
1990 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
1991 * __GFP_NOWARN set) should not cause reclaim since the subsystem
1992 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
1993 * using a larger set of nodes after it has established that the
1994 * allowed per node queues are empty and that nodes are
1997 if (NUMA_BUILD
&& (gfp_mask
& GFP_THISNODE
) == GFP_THISNODE
)
2001 wake_all_kswapd(order
, zonelist
, high_zoneidx
);
2004 * OK, we're below the kswapd watermark and have kicked background
2005 * reclaim. Now things get more complex, so set up alloc_flags according
2006 * to how we want to proceed.
2008 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
2010 /* This is the last chance, in general, before the goto nopage. */
2011 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
, zonelist
,
2012 high_zoneidx
, alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2013 preferred_zone
, migratetype
);
2018 /* Allocate without watermarks if the context allows */
2019 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
2020 page
= __alloc_pages_high_priority(gfp_mask
, order
,
2021 zonelist
, high_zoneidx
, nodemask
,
2022 preferred_zone
, migratetype
);
2027 /* Atomic allocations - we can't balance anything */
2031 /* Avoid recursion of direct reclaim */
2032 if (p
->flags
& PF_MEMALLOC
)
2035 /* Avoid allocations with no watermarks from looping endlessly */
2036 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
2039 /* Try direct compaction */
2040 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
2041 zonelist
, high_zoneidx
,
2043 alloc_flags
, preferred_zone
,
2044 migratetype
, &did_some_progress
);
2048 /* Try direct reclaim and then allocating */
2049 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
,
2050 zonelist
, high_zoneidx
,
2052 alloc_flags
, preferred_zone
,
2053 migratetype
, &did_some_progress
);
2058 * If we failed to make any progress reclaiming, then we are
2059 * running out of options and have to consider going OOM
2061 if (!did_some_progress
) {
2062 if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
2063 if (oom_killer_disabled
)
2065 page
= __alloc_pages_may_oom(gfp_mask
, order
,
2066 zonelist
, high_zoneidx
,
2067 nodemask
, preferred_zone
,
2072 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2074 * The oom killer is not called for high-order
2075 * allocations that may fail, so if no progress
2076 * is being made, there are no other options and
2077 * retrying is unlikely to help.
2079 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2082 * The oom killer is not called for lowmem
2083 * allocations to prevent needlessly killing
2086 if (high_zoneidx
< ZONE_NORMAL
)
2094 /* Check if we should retry the allocation */
2095 pages_reclaimed
+= did_some_progress
;
2096 if (should_alloc_retry(gfp_mask
, order
, pages_reclaimed
)) {
2097 /* Wait for some write requests to complete then retry */
2098 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2103 if (!(gfp_mask
& __GFP_NOWARN
) && printk_ratelimit()) {
2104 printk(KERN_WARNING
"%s: page allocation failure."
2105 " order:%d, mode:0x%x\n",
2106 p
->comm
, order
, gfp_mask
);
2112 if (kmemcheck_enabled
)
2113 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
2119 * This is the 'heart' of the zoned buddy allocator.
2122 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
2123 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
2125 enum zone_type high_zoneidx
= gfp_zone(gfp_mask
);
2126 struct zone
*preferred_zone
;
2128 int migratetype
= allocflags_to_migratetype(gfp_mask
);
2130 gfp_mask
&= gfp_allowed_mask
;
2132 lockdep_trace_alloc(gfp_mask
);
2134 might_sleep_if(gfp_mask
& __GFP_WAIT
);
2136 if (should_fail_alloc_page(gfp_mask
, order
))
2140 * Check the zones suitable for the gfp_mask contain at least one
2141 * valid zone. It's possible to have an empty zonelist as a result
2142 * of GFP_THISNODE and a memoryless node
2144 if (unlikely(!zonelist
->_zonerefs
->zone
))
2148 /* The preferred zone is used for statistics later */
2149 first_zones_zonelist(zonelist
, high_zoneidx
, nodemask
, &preferred_zone
);
2150 if (!preferred_zone
) {
2155 /* First allocation attempt */
2156 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
, order
,
2157 zonelist
, high_zoneidx
, ALLOC_WMARK_LOW
|ALLOC_CPUSET
,
2158 preferred_zone
, migratetype
);
2159 if (unlikely(!page
))
2160 page
= __alloc_pages_slowpath(gfp_mask
, order
,
2161 zonelist
, high_zoneidx
, nodemask
,
2162 preferred_zone
, migratetype
);
2165 trace_mm_page_alloc(page
, order
, gfp_mask
, migratetype
);
2168 EXPORT_SYMBOL(__alloc_pages_nodemask
);
2171 * Common helper functions.
2173 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
2178 * __get_free_pages() returns a 32-bit address, which cannot represent
2181 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
2183 page
= alloc_pages(gfp_mask
, order
);
2186 return (unsigned long) page_address(page
);
2188 EXPORT_SYMBOL(__get_free_pages
);
2190 unsigned long get_zeroed_page(gfp_t gfp_mask
)
2192 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
2194 EXPORT_SYMBOL(get_zeroed_page
);
2196 void __pagevec_free(struct pagevec
*pvec
)
2198 int i
= pagevec_count(pvec
);
2201 trace_mm_pagevec_free(pvec
->pages
[i
], pvec
->cold
);
2202 free_hot_cold_page(pvec
->pages
[i
], pvec
->cold
);
2206 void __free_pages(struct page
*page
, unsigned int order
)
2208 if (put_page_testzero(page
)) {
2210 free_hot_cold_page(page
, 0);
2212 __free_pages_ok(page
, order
);
2216 EXPORT_SYMBOL(__free_pages
);
2218 void free_pages(unsigned long addr
, unsigned int order
)
2221 VM_BUG_ON(!virt_addr_valid((void *)addr
));
2222 __free_pages(virt_to_page((void *)addr
), order
);
2226 EXPORT_SYMBOL(free_pages
);
2229 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2230 * @size: the number of bytes to allocate
2231 * @gfp_mask: GFP flags for the allocation
2233 * This function is similar to alloc_pages(), except that it allocates the
2234 * minimum number of pages to satisfy the request. alloc_pages() can only
2235 * allocate memory in power-of-two pages.
2237 * This function is also limited by MAX_ORDER.
2239 * Memory allocated by this function must be released by free_pages_exact().
2241 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
2243 unsigned int order
= get_order(size
);
2246 addr
= __get_free_pages(gfp_mask
, order
);
2248 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
2249 unsigned long used
= addr
+ PAGE_ALIGN(size
);
2251 split_page(virt_to_page((void *)addr
), order
);
2252 while (used
< alloc_end
) {
2258 return (void *)addr
;
2260 EXPORT_SYMBOL(alloc_pages_exact
);
2263 * free_pages_exact - release memory allocated via alloc_pages_exact()
2264 * @virt: the value returned by alloc_pages_exact.
2265 * @size: size of allocation, same value as passed to alloc_pages_exact().
2267 * Release the memory allocated by a previous call to alloc_pages_exact.
2269 void free_pages_exact(void *virt
, size_t size
)
2271 unsigned long addr
= (unsigned long)virt
;
2272 unsigned long end
= addr
+ PAGE_ALIGN(size
);
2274 while (addr
< end
) {
2279 EXPORT_SYMBOL(free_pages_exact
);
2281 static unsigned int nr_free_zone_pages(int offset
)
2286 /* Just pick one node, since fallback list is circular */
2287 unsigned int sum
= 0;
2289 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
2291 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
2292 unsigned long size
= zone
->present_pages
;
2293 unsigned long high
= high_wmark_pages(zone
);
2302 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
2304 unsigned int nr_free_buffer_pages(void)
2306 return nr_free_zone_pages(gfp_zone(GFP_USER
));
2308 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
2311 * Amount of free RAM allocatable within all zones
2313 unsigned int nr_free_pagecache_pages(void)
2315 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
2318 static inline void show_node(struct zone
*zone
)
2321 printk("Node %d ", zone_to_nid(zone
));
2324 void si_meminfo(struct sysinfo
*val
)
2326 val
->totalram
= totalram_pages
;
2328 val
->freeram
= global_page_state(NR_FREE_PAGES
);
2329 val
->bufferram
= nr_blockdev_pages();
2330 val
->totalhigh
= totalhigh_pages
;
2331 val
->freehigh
= nr_free_highpages();
2332 val
->mem_unit
= PAGE_SIZE
;
2335 EXPORT_SYMBOL(si_meminfo
);
2338 void si_meminfo_node(struct sysinfo
*val
, int nid
)
2340 pg_data_t
*pgdat
= NODE_DATA(nid
);
2342 val
->totalram
= pgdat
->node_present_pages
;
2343 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
2344 #ifdef CONFIG_HIGHMEM
2345 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
2346 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
2352 val
->mem_unit
= PAGE_SIZE
;
2356 #define K(x) ((x) << (PAGE_SHIFT-10))
2359 * Show free area list (used inside shift_scroll-lock stuff)
2360 * We also calculate the percentage fragmentation. We do this by counting the
2361 * memory on each free list with the exception of the first item on the list.
2363 void show_free_areas(void)
2368 for_each_populated_zone(zone
) {
2370 printk("%s per-cpu:\n", zone
->name
);
2372 for_each_online_cpu(cpu
) {
2373 struct per_cpu_pageset
*pageset
;
2375 pageset
= per_cpu_ptr(zone
->pageset
, cpu
);
2377 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
2378 cpu
, pageset
->pcp
.high
,
2379 pageset
->pcp
.batch
, pageset
->pcp
.count
);
2383 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
2384 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
2386 " dirty:%lu writeback:%lu unstable:%lu\n"
2387 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2388 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
2389 global_page_state(NR_ACTIVE_ANON
),
2390 global_page_state(NR_INACTIVE_ANON
),
2391 global_page_state(NR_ISOLATED_ANON
),
2392 global_page_state(NR_ACTIVE_FILE
),
2393 global_page_state(NR_INACTIVE_FILE
),
2394 global_page_state(NR_ISOLATED_FILE
),
2395 global_page_state(NR_UNEVICTABLE
),
2396 global_page_state(NR_FILE_DIRTY
),
2397 global_page_state(NR_WRITEBACK
),
2398 global_page_state(NR_UNSTABLE_NFS
),
2399 global_page_state(NR_FREE_PAGES
),
2400 global_page_state(NR_SLAB_RECLAIMABLE
),
2401 global_page_state(NR_SLAB_UNRECLAIMABLE
),
2402 global_page_state(NR_FILE_MAPPED
),
2403 global_page_state(NR_SHMEM
),
2404 global_page_state(NR_PAGETABLE
),
2405 global_page_state(NR_BOUNCE
));
2407 for_each_populated_zone(zone
) {
2416 " active_anon:%lukB"
2417 " inactive_anon:%lukB"
2418 " active_file:%lukB"
2419 " inactive_file:%lukB"
2420 " unevictable:%lukB"
2421 " isolated(anon):%lukB"
2422 " isolated(file):%lukB"
2429 " slab_reclaimable:%lukB"
2430 " slab_unreclaimable:%lukB"
2431 " kernel_stack:%lukB"
2435 " writeback_tmp:%lukB"
2436 " pages_scanned:%lu"
2437 " all_unreclaimable? %s"
2440 K(zone_nr_free_pages(zone
)),
2441 K(min_wmark_pages(zone
)),
2442 K(low_wmark_pages(zone
)),
2443 K(high_wmark_pages(zone
)),
2444 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
2445 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
2446 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
2447 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
2448 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
2449 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
2450 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
2451 K(zone
->present_pages
),
2452 K(zone_page_state(zone
, NR_MLOCK
)),
2453 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
2454 K(zone_page_state(zone
, NR_WRITEBACK
)),
2455 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
2456 K(zone_page_state(zone
, NR_SHMEM
)),
2457 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
2458 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
2459 zone_page_state(zone
, NR_KERNEL_STACK
) *
2461 K(zone_page_state(zone
, NR_PAGETABLE
)),
2462 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
2463 K(zone_page_state(zone
, NR_BOUNCE
)),
2464 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
2465 zone
->pages_scanned
,
2466 (zone
->all_unreclaimable
? "yes" : "no")
2468 printk("lowmem_reserve[]:");
2469 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
2470 printk(" %lu", zone
->lowmem_reserve
[i
]);
2474 for_each_populated_zone(zone
) {
2475 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
2478 printk("%s: ", zone
->name
);
2480 spin_lock_irqsave(&zone
->lock
, flags
);
2481 for (order
= 0; order
< MAX_ORDER
; order
++) {
2482 nr
[order
] = zone
->free_area
[order
].nr_free
;
2483 total
+= nr
[order
] << order
;
2485 spin_unlock_irqrestore(&zone
->lock
, flags
);
2486 for (order
= 0; order
< MAX_ORDER
; order
++)
2487 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
2488 printk("= %lukB\n", K(total
));
2491 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
2493 show_swap_cache_info();
2496 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
2498 zoneref
->zone
= zone
;
2499 zoneref
->zone_idx
= zone_idx(zone
);
2503 * Builds allocation fallback zone lists.
2505 * Add all populated zones of a node to the zonelist.
2507 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
2508 int nr_zones
, enum zone_type zone_type
)
2512 BUG_ON(zone_type
>= MAX_NR_ZONES
);
2517 zone
= pgdat
->node_zones
+ zone_type
;
2518 if (populated_zone(zone
)) {
2519 zoneref_set_zone(zone
,
2520 &zonelist
->_zonerefs
[nr_zones
++]);
2521 check_highest_zone(zone_type
);
2524 } while (zone_type
);
2531 * 0 = automatic detection of better ordering.
2532 * 1 = order by ([node] distance, -zonetype)
2533 * 2 = order by (-zonetype, [node] distance)
2535 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
2536 * the same zonelist. So only NUMA can configure this param.
2538 #define ZONELIST_ORDER_DEFAULT 0
2539 #define ZONELIST_ORDER_NODE 1
2540 #define ZONELIST_ORDER_ZONE 2
2542 /* zonelist order in the kernel.
2543 * set_zonelist_order() will set this to NODE or ZONE.
2545 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2546 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
2550 /* The value user specified ....changed by config */
2551 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2552 /* string for sysctl */
2553 #define NUMA_ZONELIST_ORDER_LEN 16
2554 char numa_zonelist_order
[16] = "default";
2557 * interface for configure zonelist ordering.
2558 * command line option "numa_zonelist_order"
2559 * = "[dD]efault - default, automatic configuration.
2560 * = "[nN]ode - order by node locality, then by zone within node
2561 * = "[zZ]one - order by zone, then by locality within zone
2564 static int __parse_numa_zonelist_order(char *s
)
2566 if (*s
== 'd' || *s
== 'D') {
2567 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2568 } else if (*s
== 'n' || *s
== 'N') {
2569 user_zonelist_order
= ZONELIST_ORDER_NODE
;
2570 } else if (*s
== 'z' || *s
== 'Z') {
2571 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
2574 "Ignoring invalid numa_zonelist_order value: "
2581 static __init
int setup_numa_zonelist_order(char *s
)
2584 return __parse_numa_zonelist_order(s
);
2587 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
2590 * sysctl handler for numa_zonelist_order
2592 int numa_zonelist_order_handler(ctl_table
*table
, int write
,
2593 void __user
*buffer
, size_t *length
,
2596 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
2598 static DEFINE_MUTEX(zl_order_mutex
);
2600 mutex_lock(&zl_order_mutex
);
2602 strcpy(saved_string
, (char*)table
->data
);
2603 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
2607 int oldval
= user_zonelist_order
;
2608 if (__parse_numa_zonelist_order((char*)table
->data
)) {
2610 * bogus value. restore saved string
2612 strncpy((char*)table
->data
, saved_string
,
2613 NUMA_ZONELIST_ORDER_LEN
);
2614 user_zonelist_order
= oldval
;
2615 } else if (oldval
!= user_zonelist_order
) {
2616 mutex_lock(&zonelists_mutex
);
2617 build_all_zonelists(NULL
);
2618 mutex_unlock(&zonelists_mutex
);
2622 mutex_unlock(&zl_order_mutex
);
2627 #define MAX_NODE_LOAD (nr_online_nodes)
2628 static int node_load
[MAX_NUMNODES
];
2631 * find_next_best_node - find the next node that should appear in a given node's fallback list
2632 * @node: node whose fallback list we're appending
2633 * @used_node_mask: nodemask_t of already used nodes
2635 * We use a number of factors to determine which is the next node that should
2636 * appear on a given node's fallback list. The node should not have appeared
2637 * already in @node's fallback list, and it should be the next closest node
2638 * according to the distance array (which contains arbitrary distance values
2639 * from each node to each node in the system), and should also prefer nodes
2640 * with no CPUs, since presumably they'll have very little allocation pressure
2641 * on them otherwise.
2642 * It returns -1 if no node is found.
2644 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
2647 int min_val
= INT_MAX
;
2649 const struct cpumask
*tmp
= cpumask_of_node(0);
2651 /* Use the local node if we haven't already */
2652 if (!node_isset(node
, *used_node_mask
)) {
2653 node_set(node
, *used_node_mask
);
2657 for_each_node_state(n
, N_HIGH_MEMORY
) {
2659 /* Don't want a node to appear more than once */
2660 if (node_isset(n
, *used_node_mask
))
2663 /* Use the distance array to find the distance */
2664 val
= node_distance(node
, n
);
2666 /* Penalize nodes under us ("prefer the next node") */
2669 /* Give preference to headless and unused nodes */
2670 tmp
= cpumask_of_node(n
);
2671 if (!cpumask_empty(tmp
))
2672 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
2674 /* Slight preference for less loaded node */
2675 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
2676 val
+= node_load
[n
];
2678 if (val
< min_val
) {
2685 node_set(best_node
, *used_node_mask
);
2692 * Build zonelists ordered by node and zones within node.
2693 * This results in maximum locality--normal zone overflows into local
2694 * DMA zone, if any--but risks exhausting DMA zone.
2696 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
2699 struct zonelist
*zonelist
;
2701 zonelist
= &pgdat
->node_zonelists
[0];
2702 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
2704 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2706 zonelist
->_zonerefs
[j
].zone
= NULL
;
2707 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2711 * Build gfp_thisnode zonelists
2713 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
2716 struct zonelist
*zonelist
;
2718 zonelist
= &pgdat
->node_zonelists
[1];
2719 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
2720 zonelist
->_zonerefs
[j
].zone
= NULL
;
2721 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2725 * Build zonelists ordered by zone and nodes within zones.
2726 * This results in conserving DMA zone[s] until all Normal memory is
2727 * exhausted, but results in overflowing to remote node while memory
2728 * may still exist in local DMA zone.
2730 static int node_order
[MAX_NUMNODES
];
2732 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
2735 int zone_type
; /* needs to be signed */
2737 struct zonelist
*zonelist
;
2739 zonelist
= &pgdat
->node_zonelists
[0];
2741 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
2742 for (j
= 0; j
< nr_nodes
; j
++) {
2743 node
= node_order
[j
];
2744 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
2745 if (populated_zone(z
)) {
2747 &zonelist
->_zonerefs
[pos
++]);
2748 check_highest_zone(zone_type
);
2752 zonelist
->_zonerefs
[pos
].zone
= NULL
;
2753 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
2756 static int default_zonelist_order(void)
2759 unsigned long low_kmem_size
,total_size
;
2763 * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
2764 * If they are really small and used heavily, the system can fall
2765 * into OOM very easily.
2766 * This function detect ZONE_DMA/DMA32 size and configures zone order.
2768 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
2771 for_each_online_node(nid
) {
2772 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
2773 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
2774 if (populated_zone(z
)) {
2775 if (zone_type
< ZONE_NORMAL
)
2776 low_kmem_size
+= z
->present_pages
;
2777 total_size
+= z
->present_pages
;
2778 } else if (zone_type
== ZONE_NORMAL
) {
2780 * If any node has only lowmem, then node order
2781 * is preferred to allow kernel allocations
2782 * locally; otherwise, they can easily infringe
2783 * on other nodes when there is an abundance of
2784 * lowmem available to allocate from.
2786 return ZONELIST_ORDER_NODE
;
2790 if (!low_kmem_size
|| /* there are no DMA area. */
2791 low_kmem_size
> total_size
/2) /* DMA/DMA32 is big. */
2792 return ZONELIST_ORDER_NODE
;
2794 * look into each node's config.
2795 * If there is a node whose DMA/DMA32 memory is very big area on
2796 * local memory, NODE_ORDER may be suitable.
2798 average_size
= total_size
/
2799 (nodes_weight(node_states
[N_HIGH_MEMORY
]) + 1);
2800 for_each_online_node(nid
) {
2803 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
2804 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
2805 if (populated_zone(z
)) {
2806 if (zone_type
< ZONE_NORMAL
)
2807 low_kmem_size
+= z
->present_pages
;
2808 total_size
+= z
->present_pages
;
2811 if (low_kmem_size
&&
2812 total_size
> average_size
&& /* ignore small node */
2813 low_kmem_size
> total_size
* 70/100)
2814 return ZONELIST_ORDER_NODE
;
2816 return ZONELIST_ORDER_ZONE
;
2819 static void set_zonelist_order(void)
2821 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
2822 current_zonelist_order
= default_zonelist_order();
2824 current_zonelist_order
= user_zonelist_order
;
2827 static void build_zonelists(pg_data_t
*pgdat
)
2831 nodemask_t used_mask
;
2832 int local_node
, prev_node
;
2833 struct zonelist
*zonelist
;
2834 int order
= current_zonelist_order
;
2836 /* initialize zonelists */
2837 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
2838 zonelist
= pgdat
->node_zonelists
+ i
;
2839 zonelist
->_zonerefs
[0].zone
= NULL
;
2840 zonelist
->_zonerefs
[0].zone_idx
= 0;
2843 /* NUMA-aware ordering of nodes */
2844 local_node
= pgdat
->node_id
;
2845 load
= nr_online_nodes
;
2846 prev_node
= local_node
;
2847 nodes_clear(used_mask
);
2849 memset(node_order
, 0, sizeof(node_order
));
2852 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
2853 int distance
= node_distance(local_node
, node
);
2856 * If another node is sufficiently far away then it is better
2857 * to reclaim pages in a zone before going off node.
2859 if (distance
> RECLAIM_DISTANCE
)
2860 zone_reclaim_mode
= 1;
2863 * We don't want to pressure a particular node.
2864 * So adding penalty to the first node in same
2865 * distance group to make it round-robin.
2867 if (distance
!= node_distance(local_node
, prev_node
))
2868 node_load
[node
] = load
;
2872 if (order
== ZONELIST_ORDER_NODE
)
2873 build_zonelists_in_node_order(pgdat
, node
);
2875 node_order
[j
++] = node
; /* remember order */
2878 if (order
== ZONELIST_ORDER_ZONE
) {
2879 /* calculate node order -- i.e., DMA last! */
2880 build_zonelists_in_zone_order(pgdat
, j
);
2883 build_thisnode_zonelists(pgdat
);
2886 /* Construct the zonelist performance cache - see further mmzone.h */
2887 static void build_zonelist_cache(pg_data_t
*pgdat
)
2889 struct zonelist
*zonelist
;
2890 struct zonelist_cache
*zlc
;
2893 zonelist
= &pgdat
->node_zonelists
[0];
2894 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
2895 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
2896 for (z
= zonelist
->_zonerefs
; z
->zone
; z
++)
2897 zlc
->z_to_n
[z
- zonelist
->_zonerefs
] = zonelist_node_idx(z
);
2900 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
2902 * Return node id of node used for "local" allocations.
2903 * I.e., first node id of first zone in arg node's generic zonelist.
2904 * Used for initializing percpu 'numa_mem', which is used primarily
2905 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
2907 int local_memory_node(int node
)
2911 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
2912 gfp_zone(GFP_KERNEL
),
2919 #else /* CONFIG_NUMA */
2921 static void set_zonelist_order(void)
2923 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
2926 static void build_zonelists(pg_data_t
*pgdat
)
2928 int node
, local_node
;
2930 struct zonelist
*zonelist
;
2932 local_node
= pgdat
->node_id
;
2934 zonelist
= &pgdat
->node_zonelists
[0];
2935 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
2938 * Now we build the zonelist so that it contains the zones
2939 * of all the other nodes.
2940 * We don't want to pressure a particular node, so when
2941 * building the zones for node N, we make sure that the
2942 * zones coming right after the local ones are those from
2943 * node N+1 (modulo N)
2945 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
2946 if (!node_online(node
))
2948 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2951 for (node
= 0; node
< local_node
; node
++) {
2952 if (!node_online(node
))
2954 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2958 zonelist
->_zonerefs
[j
].zone
= NULL
;
2959 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2962 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2963 static void build_zonelist_cache(pg_data_t
*pgdat
)
2965 pgdat
->node_zonelists
[0].zlcache_ptr
= NULL
;
2968 #endif /* CONFIG_NUMA */
2971 * Boot pageset table. One per cpu which is going to be used for all
2972 * zones and all nodes. The parameters will be set in such a way
2973 * that an item put on a list will immediately be handed over to
2974 * the buddy list. This is safe since pageset manipulation is done
2975 * with interrupts disabled.
2977 * The boot_pagesets must be kept even after bootup is complete for
2978 * unused processors and/or zones. They do play a role for bootstrapping
2979 * hotplugged processors.
2981 * zoneinfo_show() and maybe other functions do
2982 * not check if the processor is online before following the pageset pointer.
2983 * Other parts of the kernel may not check if the zone is available.
2985 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
2986 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
2987 static void setup_zone_pageset(struct zone
*zone
);
2990 * Global mutex to protect against size modification of zonelists
2991 * as well as to serialize pageset setup for the new populated zone.
2993 DEFINE_MUTEX(zonelists_mutex
);
2995 /* return values int ....just for stop_machine() */
2996 static __init_refok
int __build_all_zonelists(void *data
)
3002 memset(node_load
, 0, sizeof(node_load
));
3004 for_each_online_node(nid
) {
3005 pg_data_t
*pgdat
= NODE_DATA(nid
);
3007 build_zonelists(pgdat
);
3008 build_zonelist_cache(pgdat
);
3012 * Initialize the boot_pagesets that are going to be used
3013 * for bootstrapping processors. The real pagesets for
3014 * each zone will be allocated later when the per cpu
3015 * allocator is available.
3017 * boot_pagesets are used also for bootstrapping offline
3018 * cpus if the system is already booted because the pagesets
3019 * are needed to initialize allocators on a specific cpu too.
3020 * F.e. the percpu allocator needs the page allocator which
3021 * needs the percpu allocator in order to allocate its pagesets
3022 * (a chicken-egg dilemma).
3024 for_each_possible_cpu(cpu
) {
3025 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
3027 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3029 * We now know the "local memory node" for each node--
3030 * i.e., the node of the first zone in the generic zonelist.
3031 * Set up numa_mem percpu variable for on-line cpus. During
3032 * boot, only the boot cpu should be on-line; we'll init the
3033 * secondary cpus' numa_mem as they come on-line. During
3034 * node/memory hotplug, we'll fixup all on-line cpus.
3036 if (cpu_online(cpu
))
3037 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
3045 * Called with zonelists_mutex held always
3046 * unless system_state == SYSTEM_BOOTING.
3048 void build_all_zonelists(void *data
)
3050 set_zonelist_order();
3052 if (system_state
== SYSTEM_BOOTING
) {
3053 __build_all_zonelists(NULL
);
3054 mminit_verify_zonelist();
3055 cpuset_init_current_mems_allowed();
3057 /* we have to stop all cpus to guarantee there is no user
3059 #ifdef CONFIG_MEMORY_HOTPLUG
3061 setup_zone_pageset((struct zone
*)data
);
3063 stop_machine(__build_all_zonelists
, NULL
, NULL
);
3064 /* cpuset refresh routine should be here */
3066 vm_total_pages
= nr_free_pagecache_pages();
3068 * Disable grouping by mobility if the number of pages in the
3069 * system is too low to allow the mechanism to work. It would be
3070 * more accurate, but expensive to check per-zone. This check is
3071 * made on memory-hotadd so a system can start with mobility
3072 * disabled and enable it later
3074 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
3075 page_group_by_mobility_disabled
= 1;
3077 page_group_by_mobility_disabled
= 0;
3079 printk("Built %i zonelists in %s order, mobility grouping %s. "
3080 "Total pages: %ld\n",
3082 zonelist_order_name
[current_zonelist_order
],
3083 page_group_by_mobility_disabled
? "off" : "on",
3086 printk("Policy zone: %s\n", zone_names
[policy_zone
]);
3091 * Helper functions to size the waitqueue hash table.
3092 * Essentially these want to choose hash table sizes sufficiently
3093 * large so that collisions trying to wait on pages are rare.
3094 * But in fact, the number of active page waitqueues on typical
3095 * systems is ridiculously low, less than 200. So this is even
3096 * conservative, even though it seems large.
3098 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
3099 * waitqueues, i.e. the size of the waitq table given the number of pages.
3101 #define PAGES_PER_WAITQUEUE 256
3103 #ifndef CONFIG_MEMORY_HOTPLUG
3104 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3106 unsigned long size
= 1;
3108 pages
/= PAGES_PER_WAITQUEUE
;
3110 while (size
< pages
)
3114 * Once we have dozens or even hundreds of threads sleeping
3115 * on IO we've got bigger problems than wait queue collision.
3116 * Limit the size of the wait table to a reasonable size.
3118 size
= min(size
, 4096UL);
3120 return max(size
, 4UL);
3124 * A zone's size might be changed by hot-add, so it is not possible to determine
3125 * a suitable size for its wait_table. So we use the maximum size now.
3127 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
3129 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
3130 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
3131 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
3133 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
3134 * or more by the traditional way. (See above). It equals:
3136 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
3137 * ia64(16K page size) : = ( 8G + 4M)byte.
3138 * powerpc (64K page size) : = (32G +16M)byte.
3140 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3147 * This is an integer logarithm so that shifts can be used later
3148 * to extract the more random high bits from the multiplicative
3149 * hash function before the remainder is taken.
3151 static inline unsigned long wait_table_bits(unsigned long size
)
3156 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
3159 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3160 * of blocks reserved is based on min_wmark_pages(zone). The memory within
3161 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
3162 * higher will lead to a bigger reserve which will get freed as contiguous
3163 * blocks as reclaim kicks in
3165 static void setup_zone_migrate_reserve(struct zone
*zone
)
3167 unsigned long start_pfn
, pfn
, end_pfn
;
3169 unsigned long block_migratetype
;
3172 /* Get the start pfn, end pfn and the number of blocks to reserve */
3173 start_pfn
= zone
->zone_start_pfn
;
3174 end_pfn
= start_pfn
+ zone
->spanned_pages
;
3175 reserve
= roundup(min_wmark_pages(zone
), pageblock_nr_pages
) >>
3179 * Reserve blocks are generally in place to help high-order atomic
3180 * allocations that are short-lived. A min_free_kbytes value that
3181 * would result in more than 2 reserve blocks for atomic allocations
3182 * is assumed to be in place to help anti-fragmentation for the
3183 * future allocation of hugepages at runtime.
3185 reserve
= min(2, reserve
);
3187 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
3188 if (!pfn_valid(pfn
))
3190 page
= pfn_to_page(pfn
);
3192 /* Watch out for overlapping nodes */
3193 if (page_to_nid(page
) != zone_to_nid(zone
))
3196 /* Blocks with reserved pages will never free, skip them. */
3197 if (PageReserved(page
))
3200 block_migratetype
= get_pageblock_migratetype(page
);
3202 /* If this block is reserved, account for it */
3203 if (reserve
> 0 && block_migratetype
== MIGRATE_RESERVE
) {
3208 /* Suitable for reserving if this block is movable */
3209 if (reserve
> 0 && block_migratetype
== MIGRATE_MOVABLE
) {
3210 set_pageblock_migratetype(page
, MIGRATE_RESERVE
);
3211 move_freepages_block(zone
, page
, MIGRATE_RESERVE
);
3217 * If the reserve is met and this is a previous reserved block,
3220 if (block_migratetype
== MIGRATE_RESERVE
) {
3221 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
3222 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
3228 * Initially all pages are reserved - free ones are freed
3229 * up by free_all_bootmem() once the early boot process is
3230 * done. Non-atomic initialization, single-pass.
3232 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
3233 unsigned long start_pfn
, enum memmap_context context
)
3236 unsigned long end_pfn
= start_pfn
+ size
;
3240 if (highest_memmap_pfn
< end_pfn
- 1)
3241 highest_memmap_pfn
= end_pfn
- 1;
3243 z
= &NODE_DATA(nid
)->node_zones
[zone
];
3244 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
3246 * There can be holes in boot-time mem_map[]s
3247 * handed to this function. They do not
3248 * exist on hotplugged memory.
3250 if (context
== MEMMAP_EARLY
) {
3251 if (!early_pfn_valid(pfn
))
3253 if (!early_pfn_in_nid(pfn
, nid
))
3256 page
= pfn_to_page(pfn
);
3257 set_page_links(page
, zone
, nid
, pfn
);
3258 mminit_verify_page_links(page
, zone
, nid
, pfn
);
3259 init_page_count(page
);
3260 reset_page_mapcount(page
);
3261 SetPageReserved(page
);
3263 * Mark the block movable so that blocks are reserved for
3264 * movable at startup. This will force kernel allocations
3265 * to reserve their blocks rather than leaking throughout
3266 * the address space during boot when many long-lived
3267 * kernel allocations are made. Later some blocks near
3268 * the start are marked MIGRATE_RESERVE by
3269 * setup_zone_migrate_reserve()
3271 * bitmap is created for zone's valid pfn range. but memmap
3272 * can be created for invalid pages (for alignment)
3273 * check here not to call set_pageblock_migratetype() against
3276 if ((z
->zone_start_pfn
<= pfn
)
3277 && (pfn
< z
->zone_start_pfn
+ z
->spanned_pages
)
3278 && !(pfn
& (pageblock_nr_pages
- 1)))
3279 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
3281 INIT_LIST_HEAD(&page
->lru
);
3282 #ifdef WANT_PAGE_VIRTUAL
3283 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
3284 if (!is_highmem_idx(zone
))
3285 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
3290 static void __meminit
zone_init_free_lists(struct zone
*zone
)
3293 for_each_migratetype_order(order
, t
) {
3294 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
3295 zone
->free_area
[order
].nr_free
= 0;
3299 #ifndef __HAVE_ARCH_MEMMAP_INIT
3300 #define memmap_init(size, nid, zone, start_pfn) \
3301 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
3304 static int zone_batchsize(struct zone
*zone
)
3310 * The per-cpu-pages pools are set to around 1000th of the
3311 * size of the zone. But no more than 1/2 of a meg.
3313 * OK, so we don't know how big the cache is. So guess.
3315 batch
= zone
->present_pages
/ 1024;
3316 if (batch
* PAGE_SIZE
> 512 * 1024)
3317 batch
= (512 * 1024) / PAGE_SIZE
;
3318 batch
/= 4; /* We effectively *= 4 below */
3323 * Clamp the batch to a 2^n - 1 value. Having a power
3324 * of 2 value was found to be more likely to have
3325 * suboptimal cache aliasing properties in some cases.
3327 * For example if 2 tasks are alternately allocating
3328 * batches of pages, one task can end up with a lot
3329 * of pages of one half of the possible page colors
3330 * and the other with pages of the other colors.
3332 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
3337 /* The deferral and batching of frees should be suppressed under NOMMU
3340 * The problem is that NOMMU needs to be able to allocate large chunks
3341 * of contiguous memory as there's no hardware page translation to
3342 * assemble apparent contiguous memory from discontiguous pages.
3344 * Queueing large contiguous runs of pages for batching, however,
3345 * causes the pages to actually be freed in smaller chunks. As there
3346 * can be a significant delay between the individual batches being
3347 * recycled, this leads to the once large chunks of space being
3348 * fragmented and becoming unavailable for high-order allocations.
3354 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
3356 struct per_cpu_pages
*pcp
;
3359 memset(p
, 0, sizeof(*p
));
3363 pcp
->high
= 6 * batch
;
3364 pcp
->batch
= max(1UL, 1 * batch
);
3365 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
3366 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
3370 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
3371 * to the value high for the pageset p.
3374 static void setup_pagelist_highmark(struct per_cpu_pageset
*p
,
3377 struct per_cpu_pages
*pcp
;
3381 pcp
->batch
= max(1UL, high
/4);
3382 if ((high
/4) > (PAGE_SHIFT
* 8))
3383 pcp
->batch
= PAGE_SHIFT
* 8;
3386 static __meminit
void setup_zone_pageset(struct zone
*zone
)
3390 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
3392 for_each_possible_cpu(cpu
) {
3393 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
3395 setup_pageset(pcp
, zone_batchsize(zone
));
3397 if (percpu_pagelist_fraction
)
3398 setup_pagelist_highmark(pcp
,
3399 (zone
->present_pages
/
3400 percpu_pagelist_fraction
));
3405 * Allocate per cpu pagesets and initialize them.
3406 * Before this call only boot pagesets were available.
3408 void __init
setup_per_cpu_pageset(void)
3412 for_each_populated_zone(zone
)
3413 setup_zone_pageset(zone
);
3416 static noinline __init_refok
3417 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
3420 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
3424 * The per-page waitqueue mechanism uses hashed waitqueues
3427 zone
->wait_table_hash_nr_entries
=
3428 wait_table_hash_nr_entries(zone_size_pages
);
3429 zone
->wait_table_bits
=
3430 wait_table_bits(zone
->wait_table_hash_nr_entries
);
3431 alloc_size
= zone
->wait_table_hash_nr_entries
3432 * sizeof(wait_queue_head_t
);
3434 if (!slab_is_available()) {
3435 zone
->wait_table
= (wait_queue_head_t
*)
3436 alloc_bootmem_node(pgdat
, alloc_size
);
3439 * This case means that a zone whose size was 0 gets new memory
3440 * via memory hot-add.
3441 * But it may be the case that a new node was hot-added. In
3442 * this case vmalloc() will not be able to use this new node's
3443 * memory - this wait_table must be initialized to use this new
3444 * node itself as well.
3445 * To use this new node's memory, further consideration will be
3448 zone
->wait_table
= vmalloc(alloc_size
);
3450 if (!zone
->wait_table
)
3453 for(i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
3454 init_waitqueue_head(zone
->wait_table
+ i
);
3459 static int __zone_pcp_update(void *data
)
3461 struct zone
*zone
= data
;
3463 unsigned long batch
= zone_batchsize(zone
), flags
;
3465 for_each_possible_cpu(cpu
) {
3466 struct per_cpu_pageset
*pset
;
3467 struct per_cpu_pages
*pcp
;
3469 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
3472 local_irq_save(flags
);
3473 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
3474 setup_pageset(pset
, batch
);
3475 local_irq_restore(flags
);
3480 void zone_pcp_update(struct zone
*zone
)
3482 stop_machine(__zone_pcp_update
, zone
, NULL
);
3485 static __meminit
void zone_pcp_init(struct zone
*zone
)
3488 * per cpu subsystem is not up at this point. The following code
3489 * relies on the ability of the linker to provide the
3490 * offset of a (static) per cpu variable into the per cpu area.
3492 zone
->pageset
= &boot_pageset
;
3494 if (zone
->present_pages
)
3495 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
3496 zone
->name
, zone
->present_pages
,
3497 zone_batchsize(zone
));
3500 __meminit
int init_currently_empty_zone(struct zone
*zone
,
3501 unsigned long zone_start_pfn
,
3503 enum memmap_context context
)
3505 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
3507 ret
= zone_wait_table_init(zone
, size
);
3510 pgdat
->nr_zones
= zone_idx(zone
) + 1;
3512 zone
->zone_start_pfn
= zone_start_pfn
;
3514 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
3515 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
3517 (unsigned long)zone_idx(zone
),
3518 zone_start_pfn
, (zone_start_pfn
+ size
));
3520 zone_init_free_lists(zone
);
3525 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3527 * Basic iterator support. Return the first range of PFNs for a node
3528 * Note: nid == MAX_NUMNODES returns first region regardless of node
3530 static int __meminit
first_active_region_index_in_nid(int nid
)
3534 for (i
= 0; i
< nr_nodemap_entries
; i
++)
3535 if (nid
== MAX_NUMNODES
|| early_node_map
[i
].nid
== nid
)
3542 * Basic iterator support. Return the next active range of PFNs for a node
3543 * Note: nid == MAX_NUMNODES returns next region regardless of node
3545 static int __meminit
next_active_region_index_in_nid(int index
, int nid
)
3547 for (index
= index
+ 1; index
< nr_nodemap_entries
; index
++)
3548 if (nid
== MAX_NUMNODES
|| early_node_map
[index
].nid
== nid
)
3554 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
3556 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
3557 * Architectures may implement their own version but if add_active_range()
3558 * was used and there are no special requirements, this is a convenient
3561 int __meminit
__early_pfn_to_nid(unsigned long pfn
)
3565 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
3566 unsigned long start_pfn
= early_node_map
[i
].start_pfn
;
3567 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
3569 if (start_pfn
<= pfn
&& pfn
< end_pfn
)
3570 return early_node_map
[i
].nid
;
3572 /* This is a memory hole */
3575 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
3577 int __meminit
early_pfn_to_nid(unsigned long pfn
)
3581 nid
= __early_pfn_to_nid(pfn
);
3584 /* just returns 0 */
3588 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
3589 bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
3593 nid
= __early_pfn_to_nid(pfn
);
3594 if (nid
>= 0 && nid
!= node
)
3600 /* Basic iterator support to walk early_node_map[] */
3601 #define for_each_active_range_index_in_nid(i, nid) \
3602 for (i = first_active_region_index_in_nid(nid); i != -1; \
3603 i = next_active_region_index_in_nid(i, nid))
3606 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
3607 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
3608 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
3610 * If an architecture guarantees that all ranges registered with
3611 * add_active_ranges() contain no holes and may be freed, this
3612 * this function may be used instead of calling free_bootmem() manually.
3614 void __init
free_bootmem_with_active_regions(int nid
,
3615 unsigned long max_low_pfn
)
3619 for_each_active_range_index_in_nid(i
, nid
) {
3620 unsigned long size_pages
= 0;
3621 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
3623 if (early_node_map
[i
].start_pfn
>= max_low_pfn
)
3626 if (end_pfn
> max_low_pfn
)
3627 end_pfn
= max_low_pfn
;
3629 size_pages
= end_pfn
- early_node_map
[i
].start_pfn
;
3630 free_bootmem_node(NODE_DATA(early_node_map
[i
].nid
),
3631 PFN_PHYS(early_node_map
[i
].start_pfn
),
3632 size_pages
<< PAGE_SHIFT
);
3636 #ifdef CONFIG_HAVE_MEMBLOCK
3637 u64 __init
find_memory_core_early(int nid
, u64 size
, u64 align
,
3638 u64 goal
, u64 limit
)
3642 /* Need to go over early_node_map to find out good range for node */
3643 for_each_active_range_index_in_nid(i
, nid
) {
3645 u64 ei_start
, ei_last
;
3646 u64 final_start
, final_end
;
3648 ei_last
= early_node_map
[i
].end_pfn
;
3649 ei_last
<<= PAGE_SHIFT
;
3650 ei_start
= early_node_map
[i
].start_pfn
;
3651 ei_start
<<= PAGE_SHIFT
;
3653 final_start
= max(ei_start
, goal
);
3654 final_end
= min(ei_last
, limit
);
3656 if (final_start
>= final_end
)
3659 addr
= memblock_find_in_range(final_start
, final_end
, size
, align
);
3661 if (addr
== MEMBLOCK_ERROR
)
3667 return MEMBLOCK_ERROR
;
3671 int __init
add_from_early_node_map(struct range
*range
, int az
,
3672 int nr_range
, int nid
)
3677 /* need to go over early_node_map to find out good range for node */
3678 for_each_active_range_index_in_nid(i
, nid
) {
3679 start
= early_node_map
[i
].start_pfn
;
3680 end
= early_node_map
[i
].end_pfn
;
3681 nr_range
= add_range(range
, az
, nr_range
, start
, end
);
3686 #ifdef CONFIG_NO_BOOTMEM
3687 void * __init
__alloc_memory_core_early(int nid
, u64 size
, u64 align
,
3688 u64 goal
, u64 limit
)
3693 if (limit
> memblock
.current_limit
)
3694 limit
= memblock
.current_limit
;
3696 addr
= find_memory_core_early(nid
, size
, align
, goal
, limit
);
3698 if (addr
== MEMBLOCK_ERROR
)
3701 ptr
= phys_to_virt(addr
);
3702 memset(ptr
, 0, size
);
3703 memblock_x86_reserve_range(addr
, addr
+ size
, "BOOTMEM");
3705 * The min_count is set to 0 so that bootmem allocated blocks
3706 * are never reported as leaks.
3708 kmemleak_alloc(ptr
, size
, 0, 0);
3714 void __init
work_with_active_regions(int nid
, work_fn_t work_fn
, void *data
)
3719 for_each_active_range_index_in_nid(i
, nid
) {
3720 ret
= work_fn(early_node_map
[i
].start_pfn
,
3721 early_node_map
[i
].end_pfn
, data
);
3727 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3728 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3730 * If an architecture guarantees that all ranges registered with
3731 * add_active_ranges() contain no holes and may be freed, this
3732 * function may be used instead of calling memory_present() manually.
3734 void __init
sparse_memory_present_with_active_regions(int nid
)
3738 for_each_active_range_index_in_nid(i
, nid
)
3739 memory_present(early_node_map
[i
].nid
,
3740 early_node_map
[i
].start_pfn
,
3741 early_node_map
[i
].end_pfn
);
3745 * get_pfn_range_for_nid - Return the start and end page frames for a node
3746 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
3747 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
3748 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
3750 * It returns the start and end page frame of a node based on information
3751 * provided by an arch calling add_active_range(). If called for a node
3752 * with no available memory, a warning is printed and the start and end
3755 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
3756 unsigned long *start_pfn
, unsigned long *end_pfn
)
3762 for_each_active_range_index_in_nid(i
, nid
) {
3763 *start_pfn
= min(*start_pfn
, early_node_map
[i
].start_pfn
);
3764 *end_pfn
= max(*end_pfn
, early_node_map
[i
].end_pfn
);
3767 if (*start_pfn
== -1UL)
3772 * This finds a zone that can be used for ZONE_MOVABLE pages. The
3773 * assumption is made that zones within a node are ordered in monotonic
3774 * increasing memory addresses so that the "highest" populated zone is used
3776 static void __init
find_usable_zone_for_movable(void)
3779 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
3780 if (zone_index
== ZONE_MOVABLE
)
3783 if (arch_zone_highest_possible_pfn
[zone_index
] >
3784 arch_zone_lowest_possible_pfn
[zone_index
])
3788 VM_BUG_ON(zone_index
== -1);
3789 movable_zone
= zone_index
;
3793 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
3794 * because it is sized independant of architecture. Unlike the other zones,
3795 * the starting point for ZONE_MOVABLE is not fixed. It may be different
3796 * in each node depending on the size of each node and how evenly kernelcore
3797 * is distributed. This helper function adjusts the zone ranges
3798 * provided by the architecture for a given node by using the end of the
3799 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
3800 * zones within a node are in order of monotonic increases memory addresses
3802 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
3803 unsigned long zone_type
,
3804 unsigned long node_start_pfn
,
3805 unsigned long node_end_pfn
,
3806 unsigned long *zone_start_pfn
,
3807 unsigned long *zone_end_pfn
)
3809 /* Only adjust if ZONE_MOVABLE is on this node */
3810 if (zone_movable_pfn
[nid
]) {
3811 /* Size ZONE_MOVABLE */
3812 if (zone_type
== ZONE_MOVABLE
) {
3813 *zone_start_pfn
= zone_movable_pfn
[nid
];
3814 *zone_end_pfn
= min(node_end_pfn
,
3815 arch_zone_highest_possible_pfn
[movable_zone
]);
3817 /* Adjust for ZONE_MOVABLE starting within this range */
3818 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
3819 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
3820 *zone_end_pfn
= zone_movable_pfn
[nid
];
3822 /* Check if this whole range is within ZONE_MOVABLE */
3823 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
3824 *zone_start_pfn
= *zone_end_pfn
;
3829 * Return the number of pages a zone spans in a node, including holes
3830 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
3832 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3833 unsigned long zone_type
,
3834 unsigned long *ignored
)
3836 unsigned long node_start_pfn
, node_end_pfn
;
3837 unsigned long zone_start_pfn
, zone_end_pfn
;
3839 /* Get the start and end of the node and zone */
3840 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
3841 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
3842 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
3843 adjust_zone_range_for_zone_movable(nid
, zone_type
,
3844 node_start_pfn
, node_end_pfn
,
3845 &zone_start_pfn
, &zone_end_pfn
);
3847 /* Check that this node has pages within the zone's required range */
3848 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
3851 /* Move the zone boundaries inside the node if necessary */
3852 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
3853 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
3855 /* Return the spanned pages */
3856 return zone_end_pfn
- zone_start_pfn
;
3860 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
3861 * then all holes in the requested range will be accounted for.
3863 unsigned long __meminit
__absent_pages_in_range(int nid
,
3864 unsigned long range_start_pfn
,
3865 unsigned long range_end_pfn
)
3868 unsigned long prev_end_pfn
= 0, hole_pages
= 0;
3869 unsigned long start_pfn
;
3871 /* Find the end_pfn of the first active range of pfns in the node */
3872 i
= first_active_region_index_in_nid(nid
);
3876 prev_end_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
3878 /* Account for ranges before physical memory on this node */
3879 if (early_node_map
[i
].start_pfn
> range_start_pfn
)
3880 hole_pages
= prev_end_pfn
- range_start_pfn
;
3882 /* Find all holes for the zone within the node */
3883 for (; i
!= -1; i
= next_active_region_index_in_nid(i
, nid
)) {
3885 /* No need to continue if prev_end_pfn is outside the zone */
3886 if (prev_end_pfn
>= range_end_pfn
)
3889 /* Make sure the end of the zone is not within the hole */
3890 start_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
3891 prev_end_pfn
= max(prev_end_pfn
, range_start_pfn
);
3893 /* Update the hole size cound and move on */
3894 if (start_pfn
> range_start_pfn
) {
3895 BUG_ON(prev_end_pfn
> start_pfn
);
3896 hole_pages
+= start_pfn
- prev_end_pfn
;
3898 prev_end_pfn
= early_node_map
[i
].end_pfn
;
3901 /* Account for ranges past physical memory on this node */
3902 if (range_end_pfn
> prev_end_pfn
)
3903 hole_pages
+= range_end_pfn
-
3904 max(range_start_pfn
, prev_end_pfn
);
3910 * absent_pages_in_range - Return number of page frames in holes within a range
3911 * @start_pfn: The start PFN to start searching for holes
3912 * @end_pfn: The end PFN to stop searching for holes
3914 * It returns the number of pages frames in memory holes within a range.
3916 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
3917 unsigned long end_pfn
)
3919 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
3922 /* Return the number of page frames in holes in a zone on a node */
3923 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
3924 unsigned long zone_type
,
3925 unsigned long *ignored
)
3927 unsigned long node_start_pfn
, node_end_pfn
;
3928 unsigned long zone_start_pfn
, zone_end_pfn
;
3930 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
3931 zone_start_pfn
= max(arch_zone_lowest_possible_pfn
[zone_type
],
3933 zone_end_pfn
= min(arch_zone_highest_possible_pfn
[zone_type
],
3936 adjust_zone_range_for_zone_movable(nid
, zone_type
,
3937 node_start_pfn
, node_end_pfn
,
3938 &zone_start_pfn
, &zone_end_pfn
);
3939 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
3943 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3944 unsigned long zone_type
,
3945 unsigned long *zones_size
)
3947 return zones_size
[zone_type
];
3950 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
3951 unsigned long zone_type
,
3952 unsigned long *zholes_size
)
3957 return zholes_size
[zone_type
];
3962 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
3963 unsigned long *zones_size
, unsigned long *zholes_size
)
3965 unsigned long realtotalpages
, totalpages
= 0;
3968 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3969 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
3971 pgdat
->node_spanned_pages
= totalpages
;
3973 realtotalpages
= totalpages
;
3974 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3976 zone_absent_pages_in_node(pgdat
->node_id
, i
,
3978 pgdat
->node_present_pages
= realtotalpages
;
3979 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
3983 #ifndef CONFIG_SPARSEMEM
3985 * Calculate the size of the zone->blockflags rounded to an unsigned long
3986 * Start by making sure zonesize is a multiple of pageblock_order by rounding
3987 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
3988 * round what is now in bits to nearest long in bits, then return it in
3991 static unsigned long __init
usemap_size(unsigned long zonesize
)
3993 unsigned long usemapsize
;
3995 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
3996 usemapsize
= usemapsize
>> pageblock_order
;
3997 usemapsize
*= NR_PAGEBLOCK_BITS
;
3998 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
4000 return usemapsize
/ 8;
4003 static void __init
setup_usemap(struct pglist_data
*pgdat
,
4004 struct zone
*zone
, unsigned long zonesize
)
4006 unsigned long usemapsize
= usemap_size(zonesize
);
4007 zone
->pageblock_flags
= NULL
;
4009 zone
->pageblock_flags
= alloc_bootmem_node(pgdat
, usemapsize
);
4012 static void inline setup_usemap(struct pglist_data
*pgdat
,
4013 struct zone
*zone
, unsigned long zonesize
) {}
4014 #endif /* CONFIG_SPARSEMEM */
4016 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4018 /* Return a sensible default order for the pageblock size. */
4019 static inline int pageblock_default_order(void)
4021 if (HPAGE_SHIFT
> PAGE_SHIFT
)
4022 return HUGETLB_PAGE_ORDER
;
4027 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4028 static inline void __init
set_pageblock_order(unsigned int order
)
4030 /* Check that pageblock_nr_pages has not already been setup */
4031 if (pageblock_order
)
4035 * Assume the largest contiguous order of interest is a huge page.
4036 * This value may be variable depending on boot parameters on IA64
4038 pageblock_order
= order
;
4040 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4043 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4044 * and pageblock_default_order() are unused as pageblock_order is set
4045 * at compile-time. See include/linux/pageblock-flags.h for the values of
4046 * pageblock_order based on the kernel config
4048 static inline int pageblock_default_order(unsigned int order
)
4052 #define set_pageblock_order(x) do {} while (0)
4054 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4057 * Set up the zone data structures:
4058 * - mark all pages reserved
4059 * - mark all memory queues empty
4060 * - clear the memory bitmaps
4062 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
,
4063 unsigned long *zones_size
, unsigned long *zholes_size
)
4066 int nid
= pgdat
->node_id
;
4067 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
4070 pgdat_resize_init(pgdat
);
4071 pgdat
->nr_zones
= 0;
4072 init_waitqueue_head(&pgdat
->kswapd_wait
);
4073 pgdat
->kswapd_max_order
= 0;
4074 pgdat_page_cgroup_init(pgdat
);
4076 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4077 struct zone
*zone
= pgdat
->node_zones
+ j
;
4078 unsigned long size
, realsize
, memmap_pages
;
4081 size
= zone_spanned_pages_in_node(nid
, j
, zones_size
);
4082 realsize
= size
- zone_absent_pages_in_node(nid
, j
,
4086 * Adjust realsize so that it accounts for how much memory
4087 * is used by this zone for memmap. This affects the watermark
4088 * and per-cpu initialisations
4091 PAGE_ALIGN(size
* sizeof(struct page
)) >> PAGE_SHIFT
;
4092 if (realsize
>= memmap_pages
) {
4093 realsize
-= memmap_pages
;
4096 " %s zone: %lu pages used for memmap\n",
4097 zone_names
[j
], memmap_pages
);
4100 " %s zone: %lu pages exceeds realsize %lu\n",
4101 zone_names
[j
], memmap_pages
, realsize
);
4103 /* Account for reserved pages */
4104 if (j
== 0 && realsize
> dma_reserve
) {
4105 realsize
-= dma_reserve
;
4106 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
4107 zone_names
[0], dma_reserve
);
4110 if (!is_highmem_idx(j
))
4111 nr_kernel_pages
+= realsize
;
4112 nr_all_pages
+= realsize
;
4114 zone
->spanned_pages
= size
;
4115 zone
->present_pages
= realsize
;
4118 zone
->min_unmapped_pages
= (realsize
*sysctl_min_unmapped_ratio
)
4120 zone
->min_slab_pages
= (realsize
* sysctl_min_slab_ratio
) / 100;
4122 zone
->name
= zone_names
[j
];
4123 spin_lock_init(&zone
->lock
);
4124 spin_lock_init(&zone
->lru_lock
);
4125 zone_seqlock_init(zone
);
4126 zone
->zone_pgdat
= pgdat
;
4128 zone_pcp_init(zone
);
4130 INIT_LIST_HEAD(&zone
->lru
[l
].list
);
4131 zone
->reclaim_stat
.nr_saved_scan
[l
] = 0;
4133 zone
->reclaim_stat
.recent_rotated
[0] = 0;
4134 zone
->reclaim_stat
.recent_rotated
[1] = 0;
4135 zone
->reclaim_stat
.recent_scanned
[0] = 0;
4136 zone
->reclaim_stat
.recent_scanned
[1] = 0;
4137 zap_zone_vm_stats(zone
);
4142 set_pageblock_order(pageblock_default_order());
4143 setup_usemap(pgdat
, zone
, size
);
4144 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
4145 size
, MEMMAP_EARLY
);
4147 memmap_init(size
, nid
, j
, zone_start_pfn
);
4148 zone_start_pfn
+= size
;
4152 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
4154 /* Skip empty nodes */
4155 if (!pgdat
->node_spanned_pages
)
4158 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4159 /* ia64 gets its own node_mem_map, before this, without bootmem */
4160 if (!pgdat
->node_mem_map
) {
4161 unsigned long size
, start
, end
;
4165 * The zone's endpoints aren't required to be MAX_ORDER
4166 * aligned but the node_mem_map endpoints must be in order
4167 * for the buddy allocator to function correctly.
4169 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
4170 end
= pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
4171 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
4172 size
= (end
- start
) * sizeof(struct page
);
4173 map
= alloc_remap(pgdat
->node_id
, size
);
4175 map
= alloc_bootmem_node(pgdat
, size
);
4176 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
4178 #ifndef CONFIG_NEED_MULTIPLE_NODES
4180 * With no DISCONTIG, the global mem_map is just set as node 0's
4182 if (pgdat
== NODE_DATA(0)) {
4183 mem_map
= NODE_DATA(0)->node_mem_map
;
4184 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
4185 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
4186 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
4187 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
4190 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
4193 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
4194 unsigned long node_start_pfn
, unsigned long *zholes_size
)
4196 pg_data_t
*pgdat
= NODE_DATA(nid
);
4198 pgdat
->node_id
= nid
;
4199 pgdat
->node_start_pfn
= node_start_pfn
;
4200 calculate_node_totalpages(pgdat
, zones_size
, zholes_size
);
4202 alloc_node_mem_map(pgdat
);
4203 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4204 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
4205 nid
, (unsigned long)pgdat
,
4206 (unsigned long)pgdat
->node_mem_map
);
4209 free_area_init_core(pgdat
, zones_size
, zholes_size
);
4212 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
4214 #if MAX_NUMNODES > 1
4216 * Figure out the number of possible node ids.
4218 static void __init
setup_nr_node_ids(void)
4221 unsigned int highest
= 0;
4223 for_each_node_mask(node
, node_possible_map
)
4225 nr_node_ids
= highest
+ 1;
4228 static inline void setup_nr_node_ids(void)
4234 * add_active_range - Register a range of PFNs backed by physical memory
4235 * @nid: The node ID the range resides on
4236 * @start_pfn: The start PFN of the available physical memory
4237 * @end_pfn: The end PFN of the available physical memory
4239 * These ranges are stored in an early_node_map[] and later used by
4240 * free_area_init_nodes() to calculate zone sizes and holes. If the
4241 * range spans a memory hole, it is up to the architecture to ensure
4242 * the memory is not freed by the bootmem allocator. If possible
4243 * the range being registered will be merged with existing ranges.
4245 void __init
add_active_range(unsigned int nid
, unsigned long start_pfn
,
4246 unsigned long end_pfn
)
4250 mminit_dprintk(MMINIT_TRACE
, "memory_register",
4251 "Entering add_active_range(%d, %#lx, %#lx) "
4252 "%d entries of %d used\n",
4253 nid
, start_pfn
, end_pfn
,
4254 nr_nodemap_entries
, MAX_ACTIVE_REGIONS
);
4256 mminit_validate_memmodel_limits(&start_pfn
, &end_pfn
);
4258 /* Merge with existing active regions if possible */
4259 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
4260 if (early_node_map
[i
].nid
!= nid
)
4263 /* Skip if an existing region covers this new one */
4264 if (start_pfn
>= early_node_map
[i
].start_pfn
&&
4265 end_pfn
<= early_node_map
[i
].end_pfn
)
4268 /* Merge forward if suitable */
4269 if (start_pfn
<= early_node_map
[i
].end_pfn
&&
4270 end_pfn
> early_node_map
[i
].end_pfn
) {
4271 early_node_map
[i
].end_pfn
= end_pfn
;
4275 /* Merge backward if suitable */
4276 if (start_pfn
< early_node_map
[i
].start_pfn
&&
4277 end_pfn
>= early_node_map
[i
].start_pfn
) {
4278 early_node_map
[i
].start_pfn
= start_pfn
;
4283 /* Check that early_node_map is large enough */
4284 if (i
>= MAX_ACTIVE_REGIONS
) {
4285 printk(KERN_CRIT
"More than %d memory regions, truncating\n",
4286 MAX_ACTIVE_REGIONS
);
4290 early_node_map
[i
].nid
= nid
;
4291 early_node_map
[i
].start_pfn
= start_pfn
;
4292 early_node_map
[i
].end_pfn
= end_pfn
;
4293 nr_nodemap_entries
= i
+ 1;
4297 * remove_active_range - Shrink an existing registered range of PFNs
4298 * @nid: The node id the range is on that should be shrunk
4299 * @start_pfn: The new PFN of the range
4300 * @end_pfn: The new PFN of the range
4302 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
4303 * The map is kept near the end physical page range that has already been
4304 * registered. This function allows an arch to shrink an existing registered
4307 void __init
remove_active_range(unsigned int nid
, unsigned long start_pfn
,
4308 unsigned long end_pfn
)
4313 printk(KERN_DEBUG
"remove_active_range (%d, %lu, %lu)\n",
4314 nid
, start_pfn
, end_pfn
);
4316 /* Find the old active region end and shrink */
4317 for_each_active_range_index_in_nid(i
, nid
) {
4318 if (early_node_map
[i
].start_pfn
>= start_pfn
&&
4319 early_node_map
[i
].end_pfn
<= end_pfn
) {
4321 early_node_map
[i
].start_pfn
= 0;
4322 early_node_map
[i
].end_pfn
= 0;
4326 if (early_node_map
[i
].start_pfn
< start_pfn
&&
4327 early_node_map
[i
].end_pfn
> start_pfn
) {
4328 unsigned long temp_end_pfn
= early_node_map
[i
].end_pfn
;
4329 early_node_map
[i
].end_pfn
= start_pfn
;
4330 if (temp_end_pfn
> end_pfn
)
4331 add_active_range(nid
, end_pfn
, temp_end_pfn
);
4334 if (early_node_map
[i
].start_pfn
>= start_pfn
&&
4335 early_node_map
[i
].end_pfn
> end_pfn
&&
4336 early_node_map
[i
].start_pfn
< end_pfn
) {
4337 early_node_map
[i
].start_pfn
= end_pfn
;
4345 /* remove the blank ones */
4346 for (i
= nr_nodemap_entries
- 1; i
> 0; i
--) {
4347 if (early_node_map
[i
].nid
!= nid
)
4349 if (early_node_map
[i
].end_pfn
)
4351 /* we found it, get rid of it */
4352 for (j
= i
; j
< nr_nodemap_entries
- 1; j
++)
4353 memcpy(&early_node_map
[j
], &early_node_map
[j
+1],
4354 sizeof(early_node_map
[j
]));
4355 j
= nr_nodemap_entries
- 1;
4356 memset(&early_node_map
[j
], 0, sizeof(early_node_map
[j
]));
4357 nr_nodemap_entries
--;
4362 * remove_all_active_ranges - Remove all currently registered regions
4364 * During discovery, it may be found that a table like SRAT is invalid
4365 * and an alternative discovery method must be used. This function removes
4366 * all currently registered regions.
4368 void __init
remove_all_active_ranges(void)
4370 memset(early_node_map
, 0, sizeof(early_node_map
));
4371 nr_nodemap_entries
= 0;
4374 /* Compare two active node_active_regions */
4375 static int __init
cmp_node_active_region(const void *a
, const void *b
)
4377 struct node_active_region
*arange
= (struct node_active_region
*)a
;
4378 struct node_active_region
*brange
= (struct node_active_region
*)b
;
4380 /* Done this way to avoid overflows */
4381 if (arange
->start_pfn
> brange
->start_pfn
)
4383 if (arange
->start_pfn
< brange
->start_pfn
)
4389 /* sort the node_map by start_pfn */
4390 void __init
sort_node_map(void)
4392 sort(early_node_map
, (size_t)nr_nodemap_entries
,
4393 sizeof(struct node_active_region
),
4394 cmp_node_active_region
, NULL
);
4397 /* Find the lowest pfn for a node */
4398 static unsigned long __init
find_min_pfn_for_node(int nid
)
4401 unsigned long min_pfn
= ULONG_MAX
;
4403 /* Assuming a sorted map, the first range found has the starting pfn */
4404 for_each_active_range_index_in_nid(i
, nid
)
4405 min_pfn
= min(min_pfn
, early_node_map
[i
].start_pfn
);
4407 if (min_pfn
== ULONG_MAX
) {
4409 "Could not find start_pfn for node %d\n", nid
);
4417 * find_min_pfn_with_active_regions - Find the minimum PFN registered
4419 * It returns the minimum PFN based on information provided via
4420 * add_active_range().
4422 unsigned long __init
find_min_pfn_with_active_regions(void)
4424 return find_min_pfn_for_node(MAX_NUMNODES
);
4428 * early_calculate_totalpages()
4429 * Sum pages in active regions for movable zone.
4430 * Populate N_HIGH_MEMORY for calculating usable_nodes.
4432 static unsigned long __init
early_calculate_totalpages(void)
4435 unsigned long totalpages
= 0;
4437 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
4438 unsigned long pages
= early_node_map
[i
].end_pfn
-
4439 early_node_map
[i
].start_pfn
;
4440 totalpages
+= pages
;
4442 node_set_state(early_node_map
[i
].nid
, N_HIGH_MEMORY
);
4448 * Find the PFN the Movable zone begins in each node. Kernel memory
4449 * is spread evenly between nodes as long as the nodes have enough
4450 * memory. When they don't, some nodes will have more kernelcore than
4453 static void __init
find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn
)
4456 unsigned long usable_startpfn
;
4457 unsigned long kernelcore_node
, kernelcore_remaining
;
4458 /* save the state before borrow the nodemask */
4459 nodemask_t saved_node_state
= node_states
[N_HIGH_MEMORY
];
4460 unsigned long totalpages
= early_calculate_totalpages();
4461 int usable_nodes
= nodes_weight(node_states
[N_HIGH_MEMORY
]);
4464 * If movablecore was specified, calculate what size of
4465 * kernelcore that corresponds so that memory usable for
4466 * any allocation type is evenly spread. If both kernelcore
4467 * and movablecore are specified, then the value of kernelcore
4468 * will be used for required_kernelcore if it's greater than
4469 * what movablecore would have allowed.
4471 if (required_movablecore
) {
4472 unsigned long corepages
;
4475 * Round-up so that ZONE_MOVABLE is at least as large as what
4476 * was requested by the user
4478 required_movablecore
=
4479 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
4480 corepages
= totalpages
- required_movablecore
;
4482 required_kernelcore
= max(required_kernelcore
, corepages
);
4485 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
4486 if (!required_kernelcore
)
4489 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
4490 find_usable_zone_for_movable();
4491 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
4494 /* Spread kernelcore memory as evenly as possible throughout nodes */
4495 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4496 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4498 * Recalculate kernelcore_node if the division per node
4499 * now exceeds what is necessary to satisfy the requested
4500 * amount of memory for the kernel
4502 if (required_kernelcore
< kernelcore_node
)
4503 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4506 * As the map is walked, we track how much memory is usable
4507 * by the kernel using kernelcore_remaining. When it is
4508 * 0, the rest of the node is usable by ZONE_MOVABLE
4510 kernelcore_remaining
= kernelcore_node
;
4512 /* Go through each range of PFNs within this node */
4513 for_each_active_range_index_in_nid(i
, nid
) {
4514 unsigned long start_pfn
, end_pfn
;
4515 unsigned long size_pages
;
4517 start_pfn
= max(early_node_map
[i
].start_pfn
,
4518 zone_movable_pfn
[nid
]);
4519 end_pfn
= early_node_map
[i
].end_pfn
;
4520 if (start_pfn
>= end_pfn
)
4523 /* Account for what is only usable for kernelcore */
4524 if (start_pfn
< usable_startpfn
) {
4525 unsigned long kernel_pages
;
4526 kernel_pages
= min(end_pfn
, usable_startpfn
)
4529 kernelcore_remaining
-= min(kernel_pages
,
4530 kernelcore_remaining
);
4531 required_kernelcore
-= min(kernel_pages
,
4532 required_kernelcore
);
4534 /* Continue if range is now fully accounted */
4535 if (end_pfn
<= usable_startpfn
) {
4538 * Push zone_movable_pfn to the end so
4539 * that if we have to rebalance
4540 * kernelcore across nodes, we will
4541 * not double account here
4543 zone_movable_pfn
[nid
] = end_pfn
;
4546 start_pfn
= usable_startpfn
;
4550 * The usable PFN range for ZONE_MOVABLE is from
4551 * start_pfn->end_pfn. Calculate size_pages as the
4552 * number of pages used as kernelcore
4554 size_pages
= end_pfn
- start_pfn
;
4555 if (size_pages
> kernelcore_remaining
)
4556 size_pages
= kernelcore_remaining
;
4557 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
4560 * Some kernelcore has been met, update counts and
4561 * break if the kernelcore for this node has been
4564 required_kernelcore
-= min(required_kernelcore
,
4566 kernelcore_remaining
-= size_pages
;
4567 if (!kernelcore_remaining
)
4573 * If there is still required_kernelcore, we do another pass with one
4574 * less node in the count. This will push zone_movable_pfn[nid] further
4575 * along on the nodes that still have memory until kernelcore is
4579 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
4582 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
4583 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
4584 zone_movable_pfn
[nid
] =
4585 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
4588 /* restore the node_state */
4589 node_states
[N_HIGH_MEMORY
] = saved_node_state
;
4592 /* Any regular memory on that node ? */
4593 static void check_for_regular_memory(pg_data_t
*pgdat
)
4595 #ifdef CONFIG_HIGHMEM
4596 enum zone_type zone_type
;
4598 for (zone_type
= 0; zone_type
<= ZONE_NORMAL
; zone_type
++) {
4599 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4600 if (zone
->present_pages
)
4601 node_set_state(zone_to_nid(zone
), N_NORMAL_MEMORY
);
4607 * free_area_init_nodes - Initialise all pg_data_t and zone data
4608 * @max_zone_pfn: an array of max PFNs for each zone
4610 * This will call free_area_init_node() for each active node in the system.
4611 * Using the page ranges provided by add_active_range(), the size of each
4612 * zone in each node and their holes is calculated. If the maximum PFN
4613 * between two adjacent zones match, it is assumed that the zone is empty.
4614 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
4615 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
4616 * starts where the previous one ended. For example, ZONE_DMA32 starts
4617 * at arch_max_dma_pfn.
4619 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
4624 /* Sort early_node_map as initialisation assumes it is sorted */
4627 /* Record where the zone boundaries are */
4628 memset(arch_zone_lowest_possible_pfn
, 0,
4629 sizeof(arch_zone_lowest_possible_pfn
));
4630 memset(arch_zone_highest_possible_pfn
, 0,
4631 sizeof(arch_zone_highest_possible_pfn
));
4632 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
4633 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
4634 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
4635 if (i
== ZONE_MOVABLE
)
4637 arch_zone_lowest_possible_pfn
[i
] =
4638 arch_zone_highest_possible_pfn
[i
-1];
4639 arch_zone_highest_possible_pfn
[i
] =
4640 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
4642 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
4643 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
4645 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
4646 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
4647 find_zone_movable_pfns_for_nodes(zone_movable_pfn
);
4649 /* Print out the zone ranges */
4650 printk("Zone PFN ranges:\n");
4651 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4652 if (i
== ZONE_MOVABLE
)
4654 printk(" %-8s ", zone_names
[i
]);
4655 if (arch_zone_lowest_possible_pfn
[i
] ==
4656 arch_zone_highest_possible_pfn
[i
])
4659 printk("%0#10lx -> %0#10lx\n",
4660 arch_zone_lowest_possible_pfn
[i
],
4661 arch_zone_highest_possible_pfn
[i
]);
4664 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
4665 printk("Movable zone start PFN for each node\n");
4666 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
4667 if (zone_movable_pfn
[i
])
4668 printk(" Node %d: %lu\n", i
, zone_movable_pfn
[i
]);
4671 /* Print out the early_node_map[] */
4672 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries
);
4673 for (i
= 0; i
< nr_nodemap_entries
; i
++)
4674 printk(" %3d: %0#10lx -> %0#10lx\n", early_node_map
[i
].nid
,
4675 early_node_map
[i
].start_pfn
,
4676 early_node_map
[i
].end_pfn
);
4678 /* Initialise every node */
4679 mminit_verify_pageflags_layout();
4680 setup_nr_node_ids();
4681 for_each_online_node(nid
) {
4682 pg_data_t
*pgdat
= NODE_DATA(nid
);
4683 free_area_init_node(nid
, NULL
,
4684 find_min_pfn_for_node(nid
), NULL
);
4686 /* Any memory on that node */
4687 if (pgdat
->node_present_pages
)
4688 node_set_state(nid
, N_HIGH_MEMORY
);
4689 check_for_regular_memory(pgdat
);
4693 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
4695 unsigned long long coremem
;
4699 coremem
= memparse(p
, &p
);
4700 *core
= coremem
>> PAGE_SHIFT
;
4702 /* Paranoid check that UL is enough for the coremem value */
4703 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
4709 * kernelcore=size sets the amount of memory for use for allocations that
4710 * cannot be reclaimed or migrated.
4712 static int __init
cmdline_parse_kernelcore(char *p
)
4714 return cmdline_parse_core(p
, &required_kernelcore
);
4718 * movablecore=size sets the amount of memory for use for allocations that
4719 * can be reclaimed or migrated.
4721 static int __init
cmdline_parse_movablecore(char *p
)
4723 return cmdline_parse_core(p
, &required_movablecore
);
4726 early_param("kernelcore", cmdline_parse_kernelcore
);
4727 early_param("movablecore", cmdline_parse_movablecore
);
4729 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
4732 * set_dma_reserve - set the specified number of pages reserved in the first zone
4733 * @new_dma_reserve: The number of pages to mark reserved
4735 * The per-cpu batchsize and zone watermarks are determined by present_pages.
4736 * In the DMA zone, a significant percentage may be consumed by kernel image
4737 * and other unfreeable allocations which can skew the watermarks badly. This
4738 * function may optionally be used to account for unfreeable pages in the
4739 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
4740 * smaller per-cpu batchsize.
4742 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
4744 dma_reserve
= new_dma_reserve
;
4747 #ifndef CONFIG_NEED_MULTIPLE_NODES
4748 struct pglist_data __refdata contig_page_data
= {
4749 #ifndef CONFIG_NO_BOOTMEM
4750 .bdata
= &bootmem_node_data
[0]
4753 EXPORT_SYMBOL(contig_page_data
);
4756 void __init
free_area_init(unsigned long *zones_size
)
4758 free_area_init_node(0, zones_size
,
4759 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
4762 static int page_alloc_cpu_notify(struct notifier_block
*self
,
4763 unsigned long action
, void *hcpu
)
4765 int cpu
= (unsigned long)hcpu
;
4767 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
4771 * Spill the event counters of the dead processor
4772 * into the current processors event counters.
4773 * This artificially elevates the count of the current
4776 vm_events_fold_cpu(cpu
);
4779 * Zero the differential counters of the dead processor
4780 * so that the vm statistics are consistent.
4782 * This is only okay since the processor is dead and cannot
4783 * race with what we are doing.
4785 refresh_cpu_vm_stats(cpu
);
4790 void __init
page_alloc_init(void)
4792 hotcpu_notifier(page_alloc_cpu_notify
, 0);
4796 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
4797 * or min_free_kbytes changes.
4799 static void calculate_totalreserve_pages(void)
4801 struct pglist_data
*pgdat
;
4802 unsigned long reserve_pages
= 0;
4803 enum zone_type i
, j
;
4805 for_each_online_pgdat(pgdat
) {
4806 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4807 struct zone
*zone
= pgdat
->node_zones
+ i
;
4808 unsigned long max
= 0;
4810 /* Find valid and maximum lowmem_reserve in the zone */
4811 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
4812 if (zone
->lowmem_reserve
[j
] > max
)
4813 max
= zone
->lowmem_reserve
[j
];
4816 /* we treat the high watermark as reserved pages. */
4817 max
+= high_wmark_pages(zone
);
4819 if (max
> zone
->present_pages
)
4820 max
= zone
->present_pages
;
4821 reserve_pages
+= max
;
4824 totalreserve_pages
= reserve_pages
;
4828 * setup_per_zone_lowmem_reserve - called whenever
4829 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
4830 * has a correct pages reserved value, so an adequate number of
4831 * pages are left in the zone after a successful __alloc_pages().
4833 static void setup_per_zone_lowmem_reserve(void)
4835 struct pglist_data
*pgdat
;
4836 enum zone_type j
, idx
;
4838 for_each_online_pgdat(pgdat
) {
4839 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4840 struct zone
*zone
= pgdat
->node_zones
+ j
;
4841 unsigned long present_pages
= zone
->present_pages
;
4843 zone
->lowmem_reserve
[j
] = 0;
4847 struct zone
*lower_zone
;
4851 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
4852 sysctl_lowmem_reserve_ratio
[idx
] = 1;
4854 lower_zone
= pgdat
->node_zones
+ idx
;
4855 lower_zone
->lowmem_reserve
[j
] = present_pages
/
4856 sysctl_lowmem_reserve_ratio
[idx
];
4857 present_pages
+= lower_zone
->present_pages
;
4862 /* update totalreserve_pages */
4863 calculate_totalreserve_pages();
4867 * setup_per_zone_wmarks - called when min_free_kbytes changes
4868 * or when memory is hot-{added|removed}
4870 * Ensures that the watermark[min,low,high] values for each zone are set
4871 * correctly with respect to min_free_kbytes.
4873 void setup_per_zone_wmarks(void)
4875 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
4876 unsigned long lowmem_pages
= 0;
4878 unsigned long flags
;
4880 /* Calculate total number of !ZONE_HIGHMEM pages */
4881 for_each_zone(zone
) {
4882 if (!is_highmem(zone
))
4883 lowmem_pages
+= zone
->present_pages
;
4886 for_each_zone(zone
) {
4889 spin_lock_irqsave(&zone
->lock
, flags
);
4890 tmp
= (u64
)pages_min
* zone
->present_pages
;
4891 do_div(tmp
, lowmem_pages
);
4892 if (is_highmem(zone
)) {
4894 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
4895 * need highmem pages, so cap pages_min to a small
4898 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
4899 * deltas controls asynch page reclaim, and so should
4900 * not be capped for highmem.
4904 min_pages
= zone
->present_pages
/ 1024;
4905 if (min_pages
< SWAP_CLUSTER_MAX
)
4906 min_pages
= SWAP_CLUSTER_MAX
;
4907 if (min_pages
> 128)
4909 zone
->watermark
[WMARK_MIN
] = min_pages
;
4912 * If it's a lowmem zone, reserve a number of pages
4913 * proportionate to the zone's size.
4915 zone
->watermark
[WMARK_MIN
] = tmp
;
4918 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + (tmp
>> 2);
4919 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + (tmp
>> 1);
4920 setup_zone_migrate_reserve(zone
);
4921 spin_unlock_irqrestore(&zone
->lock
, flags
);
4924 /* update totalreserve_pages */
4925 calculate_totalreserve_pages();
4929 * The inactive anon list should be small enough that the VM never has to
4930 * do too much work, but large enough that each inactive page has a chance
4931 * to be referenced again before it is swapped out.
4933 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
4934 * INACTIVE_ANON pages on this zone's LRU, maintained by the
4935 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
4936 * the anonymous pages are kept on the inactive list.
4939 * memory ratio inactive anon
4940 * -------------------------------------
4949 void calculate_zone_inactive_ratio(struct zone
*zone
)
4951 unsigned int gb
, ratio
;
4953 /* Zone size in gigabytes */
4954 gb
= zone
->present_pages
>> (30 - PAGE_SHIFT
);
4956 ratio
= int_sqrt(10 * gb
);
4960 zone
->inactive_ratio
= ratio
;
4963 static void __init
setup_per_zone_inactive_ratio(void)
4968 calculate_zone_inactive_ratio(zone
);
4972 * Initialise min_free_kbytes.
4974 * For small machines we want it small (128k min). For large machines
4975 * we want it large (64MB max). But it is not linear, because network
4976 * bandwidth does not increase linearly with machine size. We use
4978 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
4979 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
4995 static int __init
init_per_zone_wmark_min(void)
4997 unsigned long lowmem_kbytes
;
4999 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
5001 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
5002 if (min_free_kbytes
< 128)
5003 min_free_kbytes
= 128;
5004 if (min_free_kbytes
> 65536)
5005 min_free_kbytes
= 65536;
5006 setup_per_zone_wmarks();
5007 setup_per_zone_lowmem_reserve();
5008 setup_per_zone_inactive_ratio();
5011 module_init(init_per_zone_wmark_min
)
5014 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5015 * that we can call two helper functions whenever min_free_kbytes
5018 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
5019 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5021 proc_dointvec(table
, write
, buffer
, length
, ppos
);
5023 setup_per_zone_wmarks();
5028 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table
*table
, int write
,
5029 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5034 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5039 zone
->min_unmapped_pages
= (zone
->present_pages
*
5040 sysctl_min_unmapped_ratio
) / 100;
5044 int sysctl_min_slab_ratio_sysctl_handler(ctl_table
*table
, int write
,
5045 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5050 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5055 zone
->min_slab_pages
= (zone
->present_pages
*
5056 sysctl_min_slab_ratio
) / 100;
5062 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5063 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5064 * whenever sysctl_lowmem_reserve_ratio changes.
5066 * The reserve ratio obviously has absolutely no relation with the
5067 * minimum watermarks. The lowmem reserve ratio can only make sense
5068 * if in function of the boot time zone sizes.
5070 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
5071 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5073 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5074 setup_per_zone_lowmem_reserve();
5079 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5080 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
5081 * can have before it gets flushed back to buddy allocator.
5084 int percpu_pagelist_fraction_sysctl_handler(ctl_table
*table
, int write
,
5085 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5091 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5092 if (!write
|| (ret
== -EINVAL
))
5094 for_each_populated_zone(zone
) {
5095 for_each_possible_cpu(cpu
) {
5097 high
= zone
->present_pages
/ percpu_pagelist_fraction
;
5098 setup_pagelist_highmark(
5099 per_cpu_ptr(zone
->pageset
, cpu
), high
);
5105 int hashdist
= HASHDIST_DEFAULT
;
5108 static int __init
set_hashdist(char *str
)
5112 hashdist
= simple_strtoul(str
, &str
, 0);
5115 __setup("hashdist=", set_hashdist
);
5119 * allocate a large system hash table from bootmem
5120 * - it is assumed that the hash table must contain an exact power-of-2
5121 * quantity of entries
5122 * - limit is the number of hash buckets, not the total allocation size
5124 void *__init
alloc_large_system_hash(const char *tablename
,
5125 unsigned long bucketsize
,
5126 unsigned long numentries
,
5129 unsigned int *_hash_shift
,
5130 unsigned int *_hash_mask
,
5131 unsigned long limit
)
5133 unsigned long long max
= limit
;
5134 unsigned long log2qty
, size
;
5137 /* allow the kernel cmdline to have a say */
5139 /* round applicable memory size up to nearest megabyte */
5140 numentries
= nr_kernel_pages
;
5141 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
5142 numentries
>>= 20 - PAGE_SHIFT
;
5143 numentries
<<= 20 - PAGE_SHIFT
;
5145 /* limit to 1 bucket per 2^scale bytes of low memory */
5146 if (scale
> PAGE_SHIFT
)
5147 numentries
>>= (scale
- PAGE_SHIFT
);
5149 numentries
<<= (PAGE_SHIFT
- scale
);
5151 /* Make sure we've got at least a 0-order allocation.. */
5152 if (unlikely(flags
& HASH_SMALL
)) {
5153 /* Makes no sense without HASH_EARLY */
5154 WARN_ON(!(flags
& HASH_EARLY
));
5155 if (!(numentries
>> *_hash_shift
)) {
5156 numentries
= 1UL << *_hash_shift
;
5157 BUG_ON(!numentries
);
5159 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
5160 numentries
= PAGE_SIZE
/ bucketsize
;
5162 numentries
= roundup_pow_of_two(numentries
);
5164 /* limit allocation size to 1/16 total memory by default */
5166 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
5167 do_div(max
, bucketsize
);
5170 if (numentries
> max
)
5173 log2qty
= ilog2(numentries
);
5176 size
= bucketsize
<< log2qty
;
5177 if (flags
& HASH_EARLY
)
5178 table
= alloc_bootmem_nopanic(size
);
5180 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
5183 * If bucketsize is not a power-of-two, we may free
5184 * some pages at the end of hash table which
5185 * alloc_pages_exact() automatically does
5187 if (get_order(size
) < MAX_ORDER
) {
5188 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
5189 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
5192 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
5195 panic("Failed to allocate %s hash table\n", tablename
);
5197 printk(KERN_INFO
"%s hash table entries: %ld (order: %d, %lu bytes)\n",
5200 ilog2(size
) - PAGE_SHIFT
,
5204 *_hash_shift
= log2qty
;
5206 *_hash_mask
= (1 << log2qty
) - 1;
5211 /* Return a pointer to the bitmap storing bits affecting a block of pages */
5212 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
5215 #ifdef CONFIG_SPARSEMEM
5216 return __pfn_to_section(pfn
)->pageblock_flags
;
5218 return zone
->pageblock_flags
;
5219 #endif /* CONFIG_SPARSEMEM */
5222 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
5224 #ifdef CONFIG_SPARSEMEM
5225 pfn
&= (PAGES_PER_SECTION
-1);
5226 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
5228 pfn
= pfn
- zone
->zone_start_pfn
;
5229 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
5230 #endif /* CONFIG_SPARSEMEM */
5234 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
5235 * @page: The page within the block of interest
5236 * @start_bitidx: The first bit of interest to retrieve
5237 * @end_bitidx: The last bit of interest
5238 * returns pageblock_bits flags
5240 unsigned long get_pageblock_flags_group(struct page
*page
,
5241 int start_bitidx
, int end_bitidx
)
5244 unsigned long *bitmap
;
5245 unsigned long pfn
, bitidx
;
5246 unsigned long flags
= 0;
5247 unsigned long value
= 1;
5249 zone
= page_zone(page
);
5250 pfn
= page_to_pfn(page
);
5251 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5252 bitidx
= pfn_to_bitidx(zone
, pfn
);
5254 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5255 if (test_bit(bitidx
+ start_bitidx
, bitmap
))
5262 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
5263 * @page: The page within the block of interest
5264 * @start_bitidx: The first bit of interest
5265 * @end_bitidx: The last bit of interest
5266 * @flags: The flags to set
5268 void set_pageblock_flags_group(struct page
*page
, unsigned long flags
,
5269 int start_bitidx
, int end_bitidx
)
5272 unsigned long *bitmap
;
5273 unsigned long pfn
, bitidx
;
5274 unsigned long value
= 1;
5276 zone
= page_zone(page
);
5277 pfn
= page_to_pfn(page
);
5278 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5279 bitidx
= pfn_to_bitidx(zone
, pfn
);
5280 VM_BUG_ON(pfn
< zone
->zone_start_pfn
);
5281 VM_BUG_ON(pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
);
5283 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5285 __set_bit(bitidx
+ start_bitidx
, bitmap
);
5287 __clear_bit(bitidx
+ start_bitidx
, bitmap
);
5291 * This is designed as sub function...plz see page_isolation.c also.
5292 * set/clear page block's type to be ISOLATE.
5293 * page allocater never alloc memory from ISOLATE block.
5297 __count_immobile_pages(struct zone
*zone
, struct page
*page
, int count
)
5299 unsigned long pfn
, iter
, found
;
5301 * For avoiding noise data, lru_add_drain_all() should be called
5302 * If ZONE_MOVABLE, the zone never contains immobile pages
5304 if (zone_idx(zone
) == ZONE_MOVABLE
)
5307 if (get_pageblock_migratetype(page
) == MIGRATE_MOVABLE
)
5310 pfn
= page_to_pfn(page
);
5311 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
5312 unsigned long check
= pfn
+ iter
;
5314 if (!pfn_valid_within(check
)) {
5318 page
= pfn_to_page(check
);
5319 if (!page_count(page
)) {
5320 if (PageBuddy(page
))
5321 iter
+= (1 << page_order(page
)) - 1;
5327 * If there are RECLAIMABLE pages, we need to check it.
5328 * But now, memory offline itself doesn't call shrink_slab()
5329 * and it still to be fixed.
5332 * If the page is not RAM, page_count()should be 0.
5333 * we don't need more check. This is an _used_ not-movable page.
5335 * The problematic thing here is PG_reserved pages. PG_reserved
5336 * is set to both of a memory hole page and a _used_ kernel
5345 bool is_pageblock_removable_nolock(struct page
*page
)
5347 struct zone
*zone
= page_zone(page
);
5348 return __count_immobile_pages(zone
, page
, 0);
5351 int set_migratetype_isolate(struct page
*page
)
5354 unsigned long flags
, pfn
;
5355 struct memory_isolate_notify arg
;
5360 zone
= page_zone(page
);
5361 zone_idx
= zone_idx(zone
);
5363 spin_lock_irqsave(&zone
->lock
, flags
);
5365 pfn
= page_to_pfn(page
);
5366 arg
.start_pfn
= pfn
;
5367 arg
.nr_pages
= pageblock_nr_pages
;
5368 arg
.pages_found
= 0;
5371 * It may be possible to isolate a pageblock even if the
5372 * migratetype is not MIGRATE_MOVABLE. The memory isolation
5373 * notifier chain is used by balloon drivers to return the
5374 * number of pages in a range that are held by the balloon
5375 * driver to shrink memory. If all the pages are accounted for
5376 * by balloons, are free, or on the LRU, isolation can continue.
5377 * Later, for example, when memory hotplug notifier runs, these
5378 * pages reported as "can be isolated" should be isolated(freed)
5379 * by the balloon driver through the memory notifier chain.
5381 notifier_ret
= memory_isolate_notify(MEM_ISOLATE_COUNT
, &arg
);
5382 notifier_ret
= notifier_to_errno(notifier_ret
);
5386 * FIXME: Now, memory hotplug doesn't call shrink_slab() by itself.
5387 * We just check MOVABLE pages.
5389 if (__count_immobile_pages(zone
, page
, arg
.pages_found
))
5393 * immobile means "not-on-lru" paes. If immobile is larger than
5394 * removable-by-driver pages reported by notifier, we'll fail.
5399 set_pageblock_migratetype(page
, MIGRATE_ISOLATE
);
5400 move_freepages_block(zone
, page
, MIGRATE_ISOLATE
);
5403 spin_unlock_irqrestore(&zone
->lock
, flags
);
5409 void unset_migratetype_isolate(struct page
*page
)
5412 unsigned long flags
;
5413 zone
= page_zone(page
);
5414 spin_lock_irqsave(&zone
->lock
, flags
);
5415 if (get_pageblock_migratetype(page
) != MIGRATE_ISOLATE
)
5417 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
5418 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
5420 spin_unlock_irqrestore(&zone
->lock
, flags
);
5423 #ifdef CONFIG_MEMORY_HOTREMOVE
5425 * All pages in the range must be isolated before calling this.
5428 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
5434 unsigned long flags
;
5435 /* find the first valid pfn */
5436 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
5441 zone
= page_zone(pfn_to_page(pfn
));
5442 spin_lock_irqsave(&zone
->lock
, flags
);
5444 while (pfn
< end_pfn
) {
5445 if (!pfn_valid(pfn
)) {
5449 page
= pfn_to_page(pfn
);
5450 BUG_ON(page_count(page
));
5451 BUG_ON(!PageBuddy(page
));
5452 order
= page_order(page
);
5453 #ifdef CONFIG_DEBUG_VM
5454 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
5455 pfn
, 1 << order
, end_pfn
);
5457 list_del(&page
->lru
);
5458 rmv_page_order(page
);
5459 zone
->free_area
[order
].nr_free
--;
5460 __mod_zone_page_state(zone
, NR_FREE_PAGES
,
5462 for (i
= 0; i
< (1 << order
); i
++)
5463 SetPageReserved((page
+i
));
5464 pfn
+= (1 << order
);
5466 spin_unlock_irqrestore(&zone
->lock
, flags
);
5470 #ifdef CONFIG_MEMORY_FAILURE
5471 bool is_free_buddy_page(struct page
*page
)
5473 struct zone
*zone
= page_zone(page
);
5474 unsigned long pfn
= page_to_pfn(page
);
5475 unsigned long flags
;
5478 spin_lock_irqsave(&zone
->lock
, flags
);
5479 for (order
= 0; order
< MAX_ORDER
; order
++) {
5480 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
5482 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
5485 spin_unlock_irqrestore(&zone
->lock
, flags
);
5487 return order
< MAX_ORDER
;
5491 static struct trace_print_flags pageflag_names
[] = {
5492 {1UL << PG_locked
, "locked" },
5493 {1UL << PG_error
, "error" },
5494 {1UL << PG_referenced
, "referenced" },
5495 {1UL << PG_uptodate
, "uptodate" },
5496 {1UL << PG_dirty
, "dirty" },
5497 {1UL << PG_lru
, "lru" },
5498 {1UL << PG_active
, "active" },
5499 {1UL << PG_slab
, "slab" },
5500 {1UL << PG_owner_priv_1
, "owner_priv_1" },
5501 {1UL << PG_arch_1
, "arch_1" },
5502 {1UL << PG_reserved
, "reserved" },
5503 {1UL << PG_private
, "private" },
5504 {1UL << PG_private_2
, "private_2" },
5505 {1UL << PG_writeback
, "writeback" },
5506 #ifdef CONFIG_PAGEFLAGS_EXTENDED
5507 {1UL << PG_head
, "head" },
5508 {1UL << PG_tail
, "tail" },
5510 {1UL << PG_compound
, "compound" },
5512 {1UL << PG_swapcache
, "swapcache" },
5513 {1UL << PG_mappedtodisk
, "mappedtodisk" },
5514 {1UL << PG_reclaim
, "reclaim" },
5515 {1UL << PG_buddy
, "buddy" },
5516 {1UL << PG_swapbacked
, "swapbacked" },
5517 {1UL << PG_unevictable
, "unevictable" },
5519 {1UL << PG_mlocked
, "mlocked" },
5521 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
5522 {1UL << PG_uncached
, "uncached" },
5524 #ifdef CONFIG_MEMORY_FAILURE
5525 {1UL << PG_hwpoison
, "hwpoison" },
5530 static void dump_page_flags(unsigned long flags
)
5532 const char *delim
= "";
5536 printk(KERN_ALERT
"page flags: %#lx(", flags
);
5538 /* remove zone id */
5539 flags
&= (1UL << NR_PAGEFLAGS
) - 1;
5541 for (i
= 0; pageflag_names
[i
].name
&& flags
; i
++) {
5543 mask
= pageflag_names
[i
].mask
;
5544 if ((flags
& mask
) != mask
)
5548 printk("%s%s", delim
, pageflag_names
[i
].name
);
5552 /* check for left over flags */
5554 printk("%s%#lx", delim
, flags
);
5559 void dump_page(struct page
*page
)
5562 "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
5563 page
, page_count(page
), page_mapcount(page
),
5564 page
->mapping
, page
->index
);
5565 dump_page_flags(page
->flags
);