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/kasan.h>
29 #include <linux/module.h>
30 #include <linux/suspend.h>
31 #include <linux/pagevec.h>
32 #include <linux/blkdev.h>
33 #include <linux/slab.h>
34 #include <linux/ratelimit.h>
35 #include <linux/oom.h>
36 #include <linux/notifier.h>
37 #include <linux/topology.h>
38 #include <linux/sysctl.h>
39 #include <linux/cpu.h>
40 #include <linux/cpuset.h>
41 #include <linux/memory_hotplug.h>
42 #include <linux/nodemask.h>
43 #include <linux/vmalloc.h>
44 #include <linux/vmstat.h>
45 #include <linux/mempolicy.h>
46 #include <linux/stop_machine.h>
47 #include <linux/sort.h>
48 #include <linux/pfn.h>
49 #include <linux/backing-dev.h>
50 #include <linux/fault-inject.h>
51 #include <linux/page-isolation.h>
52 #include <linux/page_ext.h>
53 #include <linux/debugobjects.h>
54 #include <linux/kmemleak.h>
55 #include <linux/compaction.h>
56 #include <trace/events/kmem.h>
57 #include <linux/prefetch.h>
58 #include <linux/mm_inline.h>
59 #include <linux/migrate.h>
60 #include <linux/page_ext.h>
61 #include <linux/hugetlb.h>
62 #include <linux/sched/rt.h>
63 #include <linux/page_owner.h>
65 #include <asm/sections.h>
66 #include <asm/tlbflush.h>
67 #include <asm/div64.h>
70 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
71 static DEFINE_MUTEX(pcp_batch_high_lock
);
72 #define MIN_PERCPU_PAGELIST_FRACTION (8)
74 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
75 DEFINE_PER_CPU(int, numa_node
);
76 EXPORT_PER_CPU_SYMBOL(numa_node
);
79 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
81 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
82 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
83 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
84 * defined in <linux/topology.h>.
86 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
87 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
88 int _node_numa_mem_
[MAX_NUMNODES
];
92 * Array of node states.
94 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
95 [N_POSSIBLE
] = NODE_MASK_ALL
,
96 [N_ONLINE
] = { { [0] = 1UL } },
98 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
100 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
102 #ifdef CONFIG_MOVABLE_NODE
103 [N_MEMORY
] = { { [0] = 1UL } },
105 [N_CPU
] = { { [0] = 1UL } },
108 EXPORT_SYMBOL(node_states
);
110 /* Protect totalram_pages and zone->managed_pages */
111 static DEFINE_SPINLOCK(managed_page_count_lock
);
113 unsigned long totalram_pages __read_mostly
;
114 unsigned long totalreserve_pages __read_mostly
;
115 unsigned long totalcma_pages __read_mostly
;
117 * When calculating the number of globally allowed dirty pages, there
118 * is a certain number of per-zone reserves that should not be
119 * considered dirtyable memory. This is the sum of those reserves
120 * over all existing zones that contribute dirtyable memory.
122 unsigned long dirty_balance_reserve __read_mostly
;
124 int percpu_pagelist_fraction
;
125 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
127 #ifdef CONFIG_PM_SLEEP
129 * The following functions are used by the suspend/hibernate code to temporarily
130 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
131 * while devices are suspended. To avoid races with the suspend/hibernate code,
132 * they should always be called with pm_mutex held (gfp_allowed_mask also should
133 * only be modified with pm_mutex held, unless the suspend/hibernate code is
134 * guaranteed not to run in parallel with that modification).
137 static gfp_t saved_gfp_mask
;
139 void pm_restore_gfp_mask(void)
141 WARN_ON(!mutex_is_locked(&pm_mutex
));
142 if (saved_gfp_mask
) {
143 gfp_allowed_mask
= saved_gfp_mask
;
148 void pm_restrict_gfp_mask(void)
150 WARN_ON(!mutex_is_locked(&pm_mutex
));
151 WARN_ON(saved_gfp_mask
);
152 saved_gfp_mask
= gfp_allowed_mask
;
153 gfp_allowed_mask
&= ~GFP_IOFS
;
156 bool pm_suspended_storage(void)
158 if ((gfp_allowed_mask
& GFP_IOFS
) == GFP_IOFS
)
162 #endif /* CONFIG_PM_SLEEP */
164 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
165 int pageblock_order __read_mostly
;
168 static void __free_pages_ok(struct page
*page
, unsigned int order
);
171 * results with 256, 32 in the lowmem_reserve sysctl:
172 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
173 * 1G machine -> (16M dma, 784M normal, 224M high)
174 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
175 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
176 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
178 * TBD: should special case ZONE_DMA32 machines here - in those we normally
179 * don't need any ZONE_NORMAL reservation
181 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
182 #ifdef CONFIG_ZONE_DMA
185 #ifdef CONFIG_ZONE_DMA32
188 #ifdef CONFIG_HIGHMEM
194 EXPORT_SYMBOL(totalram_pages
);
196 static char * const zone_names
[MAX_NR_ZONES
] = {
197 #ifdef CONFIG_ZONE_DMA
200 #ifdef CONFIG_ZONE_DMA32
204 #ifdef CONFIG_HIGHMEM
210 int min_free_kbytes
= 1024;
211 int user_min_free_kbytes
= -1;
213 static unsigned long __meminitdata nr_kernel_pages
;
214 static unsigned long __meminitdata nr_all_pages
;
215 static unsigned long __meminitdata dma_reserve
;
217 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
218 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
219 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
220 static unsigned long __initdata required_kernelcore
;
221 static unsigned long __initdata required_movablecore
;
222 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
224 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
226 EXPORT_SYMBOL(movable_zone
);
227 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
230 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
231 int nr_online_nodes __read_mostly
= 1;
232 EXPORT_SYMBOL(nr_node_ids
);
233 EXPORT_SYMBOL(nr_online_nodes
);
236 int page_group_by_mobility_disabled __read_mostly
;
238 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
240 if (unlikely(page_group_by_mobility_disabled
&&
241 migratetype
< MIGRATE_PCPTYPES
))
242 migratetype
= MIGRATE_UNMOVABLE
;
244 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
245 PB_migrate
, PB_migrate_end
);
248 #ifdef CONFIG_DEBUG_VM
249 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
253 unsigned long pfn
= page_to_pfn(page
);
254 unsigned long sp
, start_pfn
;
257 seq
= zone_span_seqbegin(zone
);
258 start_pfn
= zone
->zone_start_pfn
;
259 sp
= zone
->spanned_pages
;
260 if (!zone_spans_pfn(zone
, pfn
))
262 } while (zone_span_seqretry(zone
, seq
));
265 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
266 pfn
, zone_to_nid(zone
), zone
->name
,
267 start_pfn
, start_pfn
+ sp
);
272 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
274 if (!pfn_valid_within(page_to_pfn(page
)))
276 if (zone
!= page_zone(page
))
282 * Temporary debugging check for pages not lying within a given zone.
284 static int bad_range(struct zone
*zone
, struct page
*page
)
286 if (page_outside_zone_boundaries(zone
, page
))
288 if (!page_is_consistent(zone
, page
))
294 static inline int bad_range(struct zone
*zone
, struct page
*page
)
300 static void bad_page(struct page
*page
, const char *reason
,
301 unsigned long bad_flags
)
303 static unsigned long resume
;
304 static unsigned long nr_shown
;
305 static unsigned long nr_unshown
;
307 /* Don't complain about poisoned pages */
308 if (PageHWPoison(page
)) {
309 page_mapcount_reset(page
); /* remove PageBuddy */
314 * Allow a burst of 60 reports, then keep quiet for that minute;
315 * or allow a steady drip of one report per second.
317 if (nr_shown
== 60) {
318 if (time_before(jiffies
, resume
)) {
324 "BUG: Bad page state: %lu messages suppressed\n",
331 resume
= jiffies
+ 60 * HZ
;
333 printk(KERN_ALERT
"BUG: Bad page state in process %s pfn:%05lx\n",
334 current
->comm
, page_to_pfn(page
));
335 dump_page_badflags(page
, reason
, bad_flags
);
340 /* Leave bad fields for debug, except PageBuddy could make trouble */
341 page_mapcount_reset(page
); /* remove PageBuddy */
342 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
346 * Higher-order pages are called "compound pages". They are structured thusly:
348 * The first PAGE_SIZE page is called the "head page".
350 * The remaining PAGE_SIZE pages are called "tail pages".
352 * All pages have PG_compound set. All tail pages have their ->first_page
353 * pointing at the head page.
355 * The first tail page's ->lru.next holds the address of the compound page's
356 * put_page() function. Its ->lru.prev holds the order of allocation.
357 * This usage means that zero-order pages may not be compound.
360 static void free_compound_page(struct page
*page
)
362 __free_pages_ok(page
, compound_order(page
));
365 void prep_compound_page(struct page
*page
, unsigned long order
)
368 int nr_pages
= 1 << order
;
370 set_compound_page_dtor(page
, free_compound_page
);
371 set_compound_order(page
, order
);
373 for (i
= 1; i
< nr_pages
; i
++) {
374 struct page
*p
= page
+ i
;
375 set_page_count(p
, 0);
376 p
->first_page
= page
;
377 /* Make sure p->first_page is always valid for PageTail() */
383 static inline void prep_zero_page(struct page
*page
, unsigned int order
,
389 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
390 * and __GFP_HIGHMEM from hard or soft interrupt context.
392 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
393 for (i
= 0; i
< (1 << order
); i
++)
394 clear_highpage(page
+ i
);
397 #ifdef CONFIG_DEBUG_PAGEALLOC
398 unsigned int _debug_guardpage_minorder
;
399 bool _debug_pagealloc_enabled __read_mostly
;
400 bool _debug_guardpage_enabled __read_mostly
;
402 static int __init
early_debug_pagealloc(char *buf
)
407 if (strcmp(buf
, "on") == 0)
408 _debug_pagealloc_enabled
= true;
412 early_param("debug_pagealloc", early_debug_pagealloc
);
414 static bool need_debug_guardpage(void)
416 /* If we don't use debug_pagealloc, we don't need guard page */
417 if (!debug_pagealloc_enabled())
423 static void init_debug_guardpage(void)
425 if (!debug_pagealloc_enabled())
428 _debug_guardpage_enabled
= true;
431 struct page_ext_operations debug_guardpage_ops
= {
432 .need
= need_debug_guardpage
,
433 .init
= init_debug_guardpage
,
436 static int __init
debug_guardpage_minorder_setup(char *buf
)
440 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
441 printk(KERN_ERR
"Bad debug_guardpage_minorder value\n");
444 _debug_guardpage_minorder
= res
;
445 printk(KERN_INFO
"Setting debug_guardpage_minorder to %lu\n", res
);
448 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup
);
450 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
451 unsigned int order
, int migratetype
)
453 struct page_ext
*page_ext
;
455 if (!debug_guardpage_enabled())
458 page_ext
= lookup_page_ext(page
);
459 __set_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
461 INIT_LIST_HEAD(&page
->lru
);
462 set_page_private(page
, order
);
463 /* Guard pages are not available for any usage */
464 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
467 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
468 unsigned int order
, int migratetype
)
470 struct page_ext
*page_ext
;
472 if (!debug_guardpage_enabled())
475 page_ext
= lookup_page_ext(page
);
476 __clear_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
478 set_page_private(page
, 0);
479 if (!is_migrate_isolate(migratetype
))
480 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
483 struct page_ext_operations debug_guardpage_ops
= { NULL
, };
484 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
485 unsigned int order
, int migratetype
) {}
486 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
487 unsigned int order
, int migratetype
) {}
490 static inline void set_page_order(struct page
*page
, unsigned int order
)
492 set_page_private(page
, order
);
493 __SetPageBuddy(page
);
496 static inline void rmv_page_order(struct page
*page
)
498 __ClearPageBuddy(page
);
499 set_page_private(page
, 0);
503 * This function checks whether a page is free && is the buddy
504 * we can do coalesce a page and its buddy if
505 * (a) the buddy is not in a hole &&
506 * (b) the buddy is in the buddy system &&
507 * (c) a page and its buddy have the same order &&
508 * (d) a page and its buddy are in the same zone.
510 * For recording whether a page is in the buddy system, we set ->_mapcount
511 * PAGE_BUDDY_MAPCOUNT_VALUE.
512 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
513 * serialized by zone->lock.
515 * For recording page's order, we use page_private(page).
517 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
520 if (!pfn_valid_within(page_to_pfn(buddy
)))
523 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
524 if (page_zone_id(page
) != page_zone_id(buddy
))
527 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
532 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
534 * zone check is done late to avoid uselessly
535 * calculating zone/node ids for pages that could
538 if (page_zone_id(page
) != page_zone_id(buddy
))
541 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
549 * Freeing function for a buddy system allocator.
551 * The concept of a buddy system is to maintain direct-mapped table
552 * (containing bit values) for memory blocks of various "orders".
553 * The bottom level table contains the map for the smallest allocatable
554 * units of memory (here, pages), and each level above it describes
555 * pairs of units from the levels below, hence, "buddies".
556 * At a high level, all that happens here is marking the table entry
557 * at the bottom level available, and propagating the changes upward
558 * as necessary, plus some accounting needed to play nicely with other
559 * parts of the VM system.
560 * At each level, we keep a list of pages, which are heads of continuous
561 * free pages of length of (1 << order) and marked with _mapcount
562 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
564 * So when we are allocating or freeing one, we can derive the state of the
565 * other. That is, if we allocate a small block, and both were
566 * free, the remainder of the region must be split into blocks.
567 * If a block is freed, and its buddy is also free, then this
568 * triggers coalescing into a block of larger size.
573 static inline void __free_one_page(struct page
*page
,
575 struct zone
*zone
, unsigned int order
,
578 unsigned long page_idx
;
579 unsigned long combined_idx
;
580 unsigned long uninitialized_var(buddy_idx
);
582 int max_order
= MAX_ORDER
;
584 VM_BUG_ON(!zone_is_initialized(zone
));
585 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
587 VM_BUG_ON(migratetype
== -1);
588 if (is_migrate_isolate(migratetype
)) {
590 * We restrict max order of merging to prevent merge
591 * between freepages on isolate pageblock and normal
592 * pageblock. Without this, pageblock isolation
593 * could cause incorrect freepage accounting.
595 max_order
= min(MAX_ORDER
, pageblock_order
+ 1);
597 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
600 page_idx
= pfn
& ((1 << max_order
) - 1);
602 VM_BUG_ON_PAGE(page_idx
& ((1 << order
) - 1), page
);
603 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
605 while (order
< max_order
- 1) {
606 buddy_idx
= __find_buddy_index(page_idx
, order
);
607 buddy
= page
+ (buddy_idx
- page_idx
);
608 if (!page_is_buddy(page
, buddy
, order
))
611 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
612 * merge with it and move up one order.
614 if (page_is_guard(buddy
)) {
615 clear_page_guard(zone
, buddy
, order
, migratetype
);
617 list_del(&buddy
->lru
);
618 zone
->free_area
[order
].nr_free
--;
619 rmv_page_order(buddy
);
621 combined_idx
= buddy_idx
& page_idx
;
622 page
= page
+ (combined_idx
- page_idx
);
623 page_idx
= combined_idx
;
626 set_page_order(page
, order
);
629 * If this is not the largest possible page, check if the buddy
630 * of the next-highest order is free. If it is, it's possible
631 * that pages are being freed that will coalesce soon. In case,
632 * that is happening, add the free page to the tail of the list
633 * so it's less likely to be used soon and more likely to be merged
634 * as a higher order page
636 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
637 struct page
*higher_page
, *higher_buddy
;
638 combined_idx
= buddy_idx
& page_idx
;
639 higher_page
= page
+ (combined_idx
- page_idx
);
640 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
641 higher_buddy
= higher_page
+ (buddy_idx
- combined_idx
);
642 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
643 list_add_tail(&page
->lru
,
644 &zone
->free_area
[order
].free_list
[migratetype
]);
649 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
651 zone
->free_area
[order
].nr_free
++;
654 static inline int free_pages_check(struct page
*page
)
656 const char *bad_reason
= NULL
;
657 unsigned long bad_flags
= 0;
659 if (unlikely(page_mapcount(page
)))
660 bad_reason
= "nonzero mapcount";
661 if (unlikely(page
->mapping
!= NULL
))
662 bad_reason
= "non-NULL mapping";
663 if (unlikely(atomic_read(&page
->_count
) != 0))
664 bad_reason
= "nonzero _count";
665 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)) {
666 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
667 bad_flags
= PAGE_FLAGS_CHECK_AT_FREE
;
670 if (unlikely(page
->mem_cgroup
))
671 bad_reason
= "page still charged to cgroup";
673 if (unlikely(bad_reason
)) {
674 bad_page(page
, bad_reason
, bad_flags
);
677 page_cpupid_reset_last(page
);
678 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
679 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
684 * Frees a number of pages from the PCP lists
685 * Assumes all pages on list are in same zone, and of same order.
686 * count is the number of pages to free.
688 * If the zone was previously in an "all pages pinned" state then look to
689 * see if this freeing clears that state.
691 * And clear the zone's pages_scanned counter, to hold off the "all pages are
692 * pinned" detection logic.
694 static void free_pcppages_bulk(struct zone
*zone
, int count
,
695 struct per_cpu_pages
*pcp
)
700 unsigned long nr_scanned
;
702 spin_lock(&zone
->lock
);
703 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
705 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
709 struct list_head
*list
;
712 * Remove pages from lists in a round-robin fashion. A
713 * batch_free count is maintained that is incremented when an
714 * empty list is encountered. This is so more pages are freed
715 * off fuller lists instead of spinning excessively around empty
720 if (++migratetype
== MIGRATE_PCPTYPES
)
722 list
= &pcp
->lists
[migratetype
];
723 } while (list_empty(list
));
725 /* This is the only non-empty list. Free them all. */
726 if (batch_free
== MIGRATE_PCPTYPES
)
727 batch_free
= to_free
;
730 int mt
; /* migratetype of the to-be-freed page */
732 page
= list_entry(list
->prev
, struct page
, lru
);
733 /* must delete as __free_one_page list manipulates */
734 list_del(&page
->lru
);
735 mt
= get_freepage_migratetype(page
);
736 if (unlikely(has_isolate_pageblock(zone
)))
737 mt
= get_pageblock_migratetype(page
);
739 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
740 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
);
741 trace_mm_page_pcpu_drain(page
, 0, mt
);
742 } while (--to_free
&& --batch_free
&& !list_empty(list
));
744 spin_unlock(&zone
->lock
);
747 static void free_one_page(struct zone
*zone
,
748 struct page
*page
, unsigned long pfn
,
752 unsigned long nr_scanned
;
753 spin_lock(&zone
->lock
);
754 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
756 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
758 if (unlikely(has_isolate_pageblock(zone
) ||
759 is_migrate_isolate(migratetype
))) {
760 migratetype
= get_pfnblock_migratetype(page
, pfn
);
762 __free_one_page(page
, pfn
, zone
, order
, migratetype
);
763 spin_unlock(&zone
->lock
);
766 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
768 if (!IS_ENABLED(CONFIG_DEBUG_VM
))
770 if (unlikely(!PageTail(page
))) {
771 bad_page(page
, "PageTail not set", 0);
774 if (unlikely(page
->first_page
!= head_page
)) {
775 bad_page(page
, "first_page not consistent", 0);
781 static bool free_pages_prepare(struct page
*page
, unsigned int order
)
783 bool compound
= PageCompound(page
);
786 VM_BUG_ON_PAGE(PageTail(page
), page
);
787 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
789 trace_mm_page_free(page
, order
);
790 kmemcheck_free_shadow(page
, order
);
791 kasan_free_pages(page
, order
);
794 page
->mapping
= NULL
;
795 bad
+= free_pages_check(page
);
796 for (i
= 1; i
< (1 << order
); i
++) {
798 bad
+= free_tail_pages_check(page
, page
+ i
);
799 bad
+= free_pages_check(page
+ i
);
804 reset_page_owner(page
, order
);
806 if (!PageHighMem(page
)) {
807 debug_check_no_locks_freed(page_address(page
),
809 debug_check_no_obj_freed(page_address(page
),
812 arch_free_page(page
, order
);
813 kernel_map_pages(page
, 1 << order
, 0);
818 static void __free_pages_ok(struct page
*page
, unsigned int order
)
822 unsigned long pfn
= page_to_pfn(page
);
824 if (!free_pages_prepare(page
, order
))
827 migratetype
= get_pfnblock_migratetype(page
, pfn
);
828 local_irq_save(flags
);
829 __count_vm_events(PGFREE
, 1 << order
);
830 set_freepage_migratetype(page
, migratetype
);
831 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
);
832 local_irq_restore(flags
);
835 void __init
__free_pages_bootmem(struct page
*page
, unsigned int order
)
837 unsigned int nr_pages
= 1 << order
;
838 struct page
*p
= page
;
842 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
844 __ClearPageReserved(p
);
845 set_page_count(p
, 0);
847 __ClearPageReserved(p
);
848 set_page_count(p
, 0);
850 page_zone(page
)->managed_pages
+= nr_pages
;
851 set_page_refcounted(page
);
852 __free_pages(page
, order
);
856 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
857 void __init
init_cma_reserved_pageblock(struct page
*page
)
859 unsigned i
= pageblock_nr_pages
;
860 struct page
*p
= page
;
863 __ClearPageReserved(p
);
864 set_page_count(p
, 0);
867 set_pageblock_migratetype(page
, MIGRATE_CMA
);
869 if (pageblock_order
>= MAX_ORDER
) {
870 i
= pageblock_nr_pages
;
873 set_page_refcounted(p
);
874 __free_pages(p
, MAX_ORDER
- 1);
875 p
+= MAX_ORDER_NR_PAGES
;
876 } while (i
-= MAX_ORDER_NR_PAGES
);
878 set_page_refcounted(page
);
879 __free_pages(page
, pageblock_order
);
882 adjust_managed_page_count(page
, pageblock_nr_pages
);
887 * The order of subdivision here is critical for the IO subsystem.
888 * Please do not alter this order without good reasons and regression
889 * testing. Specifically, as large blocks of memory are subdivided,
890 * the order in which smaller blocks are delivered depends on the order
891 * they're subdivided in this function. This is the primary factor
892 * influencing the order in which pages are delivered to the IO
893 * subsystem according to empirical testing, and this is also justified
894 * by considering the behavior of a buddy system containing a single
895 * large block of memory acted on by a series of small allocations.
896 * This behavior is a critical factor in sglist merging's success.
900 static inline void expand(struct zone
*zone
, struct page
*page
,
901 int low
, int high
, struct free_area
*area
,
904 unsigned long size
= 1 << high
;
910 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
912 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC
) &&
913 debug_guardpage_enabled() &&
914 high
< debug_guardpage_minorder()) {
916 * Mark as guard pages (or page), that will allow to
917 * merge back to allocator when buddy will be freed.
918 * Corresponding page table entries will not be touched,
919 * pages will stay not present in virtual address space
921 set_page_guard(zone
, &page
[size
], high
, migratetype
);
924 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
926 set_page_order(&page
[size
], high
);
931 * This page is about to be returned from the page allocator
933 static inline int check_new_page(struct page
*page
)
935 const char *bad_reason
= NULL
;
936 unsigned long bad_flags
= 0;
938 if (unlikely(page_mapcount(page
)))
939 bad_reason
= "nonzero mapcount";
940 if (unlikely(page
->mapping
!= NULL
))
941 bad_reason
= "non-NULL mapping";
942 if (unlikely(atomic_read(&page
->_count
) != 0))
943 bad_reason
= "nonzero _count";
944 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)) {
945 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag set";
946 bad_flags
= PAGE_FLAGS_CHECK_AT_PREP
;
949 if (unlikely(page
->mem_cgroup
))
950 bad_reason
= "page still charged to cgroup";
952 if (unlikely(bad_reason
)) {
953 bad_page(page
, bad_reason
, bad_flags
);
959 static int prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
964 for (i
= 0; i
< (1 << order
); i
++) {
965 struct page
*p
= page
+ i
;
966 if (unlikely(check_new_page(p
)))
970 set_page_private(page
, 0);
971 set_page_refcounted(page
);
973 arch_alloc_page(page
, order
);
974 kernel_map_pages(page
, 1 << order
, 1);
975 kasan_alloc_pages(page
, order
);
977 if (gfp_flags
& __GFP_ZERO
)
978 prep_zero_page(page
, order
, gfp_flags
);
980 if (order
&& (gfp_flags
& __GFP_COMP
))
981 prep_compound_page(page
, order
);
983 set_page_owner(page
, order
, gfp_flags
);
986 * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was necessary to
987 * allocate the page. The expectation is that the caller is taking
988 * steps that will free more memory. The caller should avoid the page
989 * being used for !PFMEMALLOC purposes.
991 page
->pfmemalloc
= !!(alloc_flags
& ALLOC_NO_WATERMARKS
);
997 * Go through the free lists for the given migratetype and remove
998 * the smallest available page from the freelists
1001 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
1004 unsigned int current_order
;
1005 struct free_area
*area
;
1008 /* Find a page of the appropriate size in the preferred list */
1009 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
1010 area
= &(zone
->free_area
[current_order
]);
1011 if (list_empty(&area
->free_list
[migratetype
]))
1014 page
= list_entry(area
->free_list
[migratetype
].next
,
1016 list_del(&page
->lru
);
1017 rmv_page_order(page
);
1019 expand(zone
, page
, order
, current_order
, area
, migratetype
);
1020 set_freepage_migratetype(page
, migratetype
);
1029 * This array describes the order lists are fallen back to when
1030 * the free lists for the desirable migrate type are depleted
1032 static int fallbacks
[MIGRATE_TYPES
][4] = {
1033 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
1034 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
1035 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
1037 [MIGRATE_CMA
] = { MIGRATE_RESERVE
}, /* Never used */
1039 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
}, /* Never used */
1040 #ifdef CONFIG_MEMORY_ISOLATION
1041 [MIGRATE_ISOLATE
] = { MIGRATE_RESERVE
}, /* Never used */
1046 static struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1049 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
1052 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1053 unsigned int order
) { return NULL
; }
1057 * Move the free pages in a range to the free lists of the requested type.
1058 * Note that start_page and end_pages are not aligned on a pageblock
1059 * boundary. If alignment is required, use move_freepages_block()
1061 int move_freepages(struct zone
*zone
,
1062 struct page
*start_page
, struct page
*end_page
,
1066 unsigned long order
;
1067 int pages_moved
= 0;
1069 #ifndef CONFIG_HOLES_IN_ZONE
1071 * page_zone is not safe to call in this context when
1072 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1073 * anyway as we check zone boundaries in move_freepages_block().
1074 * Remove at a later date when no bug reports exist related to
1075 * grouping pages by mobility
1077 VM_BUG_ON(page_zone(start_page
) != page_zone(end_page
));
1080 for (page
= start_page
; page
<= end_page
;) {
1081 /* Make sure we are not inadvertently changing nodes */
1082 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
1084 if (!pfn_valid_within(page_to_pfn(page
))) {
1089 if (!PageBuddy(page
)) {
1094 order
= page_order(page
);
1095 list_move(&page
->lru
,
1096 &zone
->free_area
[order
].free_list
[migratetype
]);
1097 set_freepage_migratetype(page
, migratetype
);
1099 pages_moved
+= 1 << order
;
1105 int move_freepages_block(struct zone
*zone
, struct page
*page
,
1108 unsigned long start_pfn
, end_pfn
;
1109 struct page
*start_page
, *end_page
;
1111 start_pfn
= page_to_pfn(page
);
1112 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
1113 start_page
= pfn_to_page(start_pfn
);
1114 end_page
= start_page
+ pageblock_nr_pages
- 1;
1115 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
1117 /* Do not cross zone boundaries */
1118 if (!zone_spans_pfn(zone
, start_pfn
))
1120 if (!zone_spans_pfn(zone
, end_pfn
))
1123 return move_freepages(zone
, start_page
, end_page
, migratetype
);
1126 static void change_pageblock_range(struct page
*pageblock_page
,
1127 int start_order
, int migratetype
)
1129 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
1131 while (nr_pageblocks
--) {
1132 set_pageblock_migratetype(pageblock_page
, migratetype
);
1133 pageblock_page
+= pageblock_nr_pages
;
1138 * When we are falling back to another migratetype during allocation, try to
1139 * steal extra free pages from the same pageblocks to satisfy further
1140 * allocations, instead of polluting multiple pageblocks.
1142 * If we are stealing a relatively large buddy page, it is likely there will
1143 * be more free pages in the pageblock, so try to steal them all. For
1144 * reclaimable and unmovable allocations, we steal regardless of page size,
1145 * as fragmentation caused by those allocations polluting movable pageblocks
1146 * is worse than movable allocations stealing from unmovable and reclaimable
1149 static bool can_steal_fallback(unsigned int order
, int start_mt
)
1152 * Leaving this order check is intended, although there is
1153 * relaxed order check in next check. The reason is that
1154 * we can actually steal whole pageblock if this condition met,
1155 * but, below check doesn't guarantee it and that is just heuristic
1156 * so could be changed anytime.
1158 if (order
>= pageblock_order
)
1161 if (order
>= pageblock_order
/ 2 ||
1162 start_mt
== MIGRATE_RECLAIMABLE
||
1163 start_mt
== MIGRATE_UNMOVABLE
||
1164 page_group_by_mobility_disabled
)
1171 * This function implements actual steal behaviour. If order is large enough,
1172 * we can steal whole pageblock. If not, we first move freepages in this
1173 * pageblock and check whether half of pages are moved or not. If half of
1174 * pages are moved, we can change migratetype of pageblock and permanently
1175 * use it's pages as requested migratetype in the future.
1177 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
1180 int current_order
= page_order(page
);
1183 /* Take ownership for orders >= pageblock_order */
1184 if (current_order
>= pageblock_order
) {
1185 change_pageblock_range(page
, current_order
, start_type
);
1189 pages
= move_freepages_block(zone
, page
, start_type
);
1191 /* Claim the whole block if over half of it is free */
1192 if (pages
>= (1 << (pageblock_order
-1)) ||
1193 page_group_by_mobility_disabled
)
1194 set_pageblock_migratetype(page
, start_type
);
1198 * Check whether there is a suitable fallback freepage with requested order.
1199 * If only_stealable is true, this function returns fallback_mt only if
1200 * we can steal other freepages all together. This would help to reduce
1201 * fragmentation due to mixed migratetype pages in one pageblock.
1203 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
1204 int migratetype
, bool only_stealable
, bool *can_steal
)
1209 if (area
->nr_free
== 0)
1214 fallback_mt
= fallbacks
[migratetype
][i
];
1215 if (fallback_mt
== MIGRATE_RESERVE
)
1218 if (list_empty(&area
->free_list
[fallback_mt
]))
1221 if (can_steal_fallback(order
, migratetype
))
1224 if (!only_stealable
)
1234 /* Remove an element from the buddy allocator from the fallback list */
1235 static inline struct page
*
1236 __rmqueue_fallback(struct zone
*zone
, unsigned int order
, int start_migratetype
)
1238 struct free_area
*area
;
1239 unsigned int current_order
;
1244 /* Find the largest possible block of pages in the other list */
1245 for (current_order
= MAX_ORDER
-1;
1246 current_order
>= order
&& current_order
<= MAX_ORDER
-1;
1248 area
= &(zone
->free_area
[current_order
]);
1249 fallback_mt
= find_suitable_fallback(area
, current_order
,
1250 start_migratetype
, false, &can_steal
);
1251 if (fallback_mt
== -1)
1254 page
= list_entry(area
->free_list
[fallback_mt
].next
,
1257 steal_suitable_fallback(zone
, page
, start_migratetype
);
1259 /* Remove the page from the freelists */
1261 list_del(&page
->lru
);
1262 rmv_page_order(page
);
1264 expand(zone
, page
, order
, current_order
, area
,
1267 * The freepage_migratetype may differ from pageblock's
1268 * migratetype depending on the decisions in
1269 * try_to_steal_freepages(). This is OK as long as it
1270 * does not differ for MIGRATE_CMA pageblocks. For CMA
1271 * we need to make sure unallocated pages flushed from
1272 * pcp lists are returned to the correct freelist.
1274 set_freepage_migratetype(page
, start_migratetype
);
1276 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
1277 start_migratetype
, fallback_mt
);
1286 * Do the hard work of removing an element from the buddy allocator.
1287 * Call me with the zone->lock already held.
1289 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
1295 page
= __rmqueue_smallest(zone
, order
, migratetype
);
1297 if (unlikely(!page
) && migratetype
!= MIGRATE_RESERVE
) {
1298 if (migratetype
== MIGRATE_MOVABLE
)
1299 page
= __rmqueue_cma_fallback(zone
, order
);
1302 page
= __rmqueue_fallback(zone
, order
, migratetype
);
1305 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1306 * is used because __rmqueue_smallest is an inline function
1307 * and we want just one call site
1310 migratetype
= MIGRATE_RESERVE
;
1315 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
1320 * Obtain a specified number of elements from the buddy allocator, all under
1321 * a single hold of the lock, for efficiency. Add them to the supplied list.
1322 * Returns the number of new pages which were placed at *list.
1324 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
1325 unsigned long count
, struct list_head
*list
,
1326 int migratetype
, bool cold
)
1330 spin_lock(&zone
->lock
);
1331 for (i
= 0; i
< count
; ++i
) {
1332 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
1333 if (unlikely(page
== NULL
))
1337 * Split buddy pages returned by expand() are received here
1338 * in physical page order. The page is added to the callers and
1339 * list and the list head then moves forward. From the callers
1340 * perspective, the linked list is ordered by page number in
1341 * some conditions. This is useful for IO devices that can
1342 * merge IO requests if the physical pages are ordered
1346 list_add(&page
->lru
, list
);
1348 list_add_tail(&page
->lru
, list
);
1350 if (is_migrate_cma(get_freepage_migratetype(page
)))
1351 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
1354 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
1355 spin_unlock(&zone
->lock
);
1361 * Called from the vmstat counter updater to drain pagesets of this
1362 * currently executing processor on remote nodes after they have
1365 * Note that this function must be called with the thread pinned to
1366 * a single processor.
1368 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
1370 unsigned long flags
;
1371 int to_drain
, batch
;
1373 local_irq_save(flags
);
1374 batch
= READ_ONCE(pcp
->batch
);
1375 to_drain
= min(pcp
->count
, batch
);
1377 free_pcppages_bulk(zone
, to_drain
, pcp
);
1378 pcp
->count
-= to_drain
;
1380 local_irq_restore(flags
);
1385 * Drain pcplists of the indicated processor and zone.
1387 * The processor must either be the current processor and the
1388 * thread pinned to the current processor or a processor that
1391 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
1393 unsigned long flags
;
1394 struct per_cpu_pageset
*pset
;
1395 struct per_cpu_pages
*pcp
;
1397 local_irq_save(flags
);
1398 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
1402 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
1405 local_irq_restore(flags
);
1409 * Drain pcplists of all zones on the indicated processor.
1411 * The processor must either be the current processor and the
1412 * thread pinned to the current processor or a processor that
1415 static void drain_pages(unsigned int cpu
)
1419 for_each_populated_zone(zone
) {
1420 drain_pages_zone(cpu
, zone
);
1425 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1427 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
1428 * the single zone's pages.
1430 void drain_local_pages(struct zone
*zone
)
1432 int cpu
= smp_processor_id();
1435 drain_pages_zone(cpu
, zone
);
1441 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
1443 * When zone parameter is non-NULL, spill just the single zone's pages.
1445 * Note that this code is protected against sending an IPI to an offline
1446 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
1447 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
1448 * nothing keeps CPUs from showing up after we populated the cpumask and
1449 * before the call to on_each_cpu_mask().
1451 void drain_all_pages(struct zone
*zone
)
1456 * Allocate in the BSS so we wont require allocation in
1457 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
1459 static cpumask_t cpus_with_pcps
;
1462 * We don't care about racing with CPU hotplug event
1463 * as offline notification will cause the notified
1464 * cpu to drain that CPU pcps and on_each_cpu_mask
1465 * disables preemption as part of its processing
1467 for_each_online_cpu(cpu
) {
1468 struct per_cpu_pageset
*pcp
;
1470 bool has_pcps
= false;
1473 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
1477 for_each_populated_zone(z
) {
1478 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
1479 if (pcp
->pcp
.count
) {
1487 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
1489 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
1491 on_each_cpu_mask(&cpus_with_pcps
, (smp_call_func_t
) drain_local_pages
,
1495 #ifdef CONFIG_HIBERNATION
1497 void mark_free_pages(struct zone
*zone
)
1499 unsigned long pfn
, max_zone_pfn
;
1500 unsigned long flags
;
1501 unsigned int order
, t
;
1502 struct list_head
*curr
;
1504 if (zone_is_empty(zone
))
1507 spin_lock_irqsave(&zone
->lock
, flags
);
1509 max_zone_pfn
= zone_end_pfn(zone
);
1510 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1511 if (pfn_valid(pfn
)) {
1512 struct page
*page
= pfn_to_page(pfn
);
1514 if (!swsusp_page_is_forbidden(page
))
1515 swsusp_unset_page_free(page
);
1518 for_each_migratetype_order(order
, t
) {
1519 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
1522 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
1523 for (i
= 0; i
< (1UL << order
); i
++)
1524 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
1527 spin_unlock_irqrestore(&zone
->lock
, flags
);
1529 #endif /* CONFIG_PM */
1532 * Free a 0-order page
1533 * cold == true ? free a cold page : free a hot page
1535 void free_hot_cold_page(struct page
*page
, bool cold
)
1537 struct zone
*zone
= page_zone(page
);
1538 struct per_cpu_pages
*pcp
;
1539 unsigned long flags
;
1540 unsigned long pfn
= page_to_pfn(page
);
1543 if (!free_pages_prepare(page
, 0))
1546 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1547 set_freepage_migratetype(page
, migratetype
);
1548 local_irq_save(flags
);
1549 __count_vm_event(PGFREE
);
1552 * We only track unmovable, reclaimable and movable on pcp lists.
1553 * Free ISOLATE pages back to the allocator because they are being
1554 * offlined but treat RESERVE as movable pages so we can get those
1555 * areas back if necessary. Otherwise, we may have to free
1556 * excessively into the page allocator
1558 if (migratetype
>= MIGRATE_PCPTYPES
) {
1559 if (unlikely(is_migrate_isolate(migratetype
))) {
1560 free_one_page(zone
, page
, pfn
, 0, migratetype
);
1563 migratetype
= MIGRATE_MOVABLE
;
1566 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1568 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
1570 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
1572 if (pcp
->count
>= pcp
->high
) {
1573 unsigned long batch
= READ_ONCE(pcp
->batch
);
1574 free_pcppages_bulk(zone
, batch
, pcp
);
1575 pcp
->count
-= batch
;
1579 local_irq_restore(flags
);
1583 * Free a list of 0-order pages
1585 void free_hot_cold_page_list(struct list_head
*list
, bool cold
)
1587 struct page
*page
, *next
;
1589 list_for_each_entry_safe(page
, next
, list
, lru
) {
1590 trace_mm_page_free_batched(page
, cold
);
1591 free_hot_cold_page(page
, cold
);
1596 * split_page takes a non-compound higher-order page, and splits it into
1597 * n (1<<order) sub-pages: page[0..n]
1598 * Each sub-page must be freed individually.
1600 * Note: this is probably too low level an operation for use in drivers.
1601 * Please consult with lkml before using this in your driver.
1603 void split_page(struct page
*page
, unsigned int order
)
1607 VM_BUG_ON_PAGE(PageCompound(page
), page
);
1608 VM_BUG_ON_PAGE(!page_count(page
), page
);
1610 #ifdef CONFIG_KMEMCHECK
1612 * Split shadow pages too, because free(page[0]) would
1613 * otherwise free the whole shadow.
1615 if (kmemcheck_page_is_tracked(page
))
1616 split_page(virt_to_page(page
[0].shadow
), order
);
1619 set_page_owner(page
, 0, 0);
1620 for (i
= 1; i
< (1 << order
); i
++) {
1621 set_page_refcounted(page
+ i
);
1622 set_page_owner(page
+ i
, 0, 0);
1625 EXPORT_SYMBOL_GPL(split_page
);
1627 int __isolate_free_page(struct page
*page
, unsigned int order
)
1629 unsigned long watermark
;
1633 BUG_ON(!PageBuddy(page
));
1635 zone
= page_zone(page
);
1636 mt
= get_pageblock_migratetype(page
);
1638 if (!is_migrate_isolate(mt
)) {
1639 /* Obey watermarks as if the page was being allocated */
1640 watermark
= low_wmark_pages(zone
) + (1 << order
);
1641 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
1644 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
1647 /* Remove page from free list */
1648 list_del(&page
->lru
);
1649 zone
->free_area
[order
].nr_free
--;
1650 rmv_page_order(page
);
1652 /* Set the pageblock if the isolated page is at least a pageblock */
1653 if (order
>= pageblock_order
- 1) {
1654 struct page
*endpage
= page
+ (1 << order
) - 1;
1655 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
1656 int mt
= get_pageblock_migratetype(page
);
1657 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
))
1658 set_pageblock_migratetype(page
,
1663 set_page_owner(page
, order
, 0);
1664 return 1UL << order
;
1668 * Similar to split_page except the page is already free. As this is only
1669 * being used for migration, the migratetype of the block also changes.
1670 * As this is called with interrupts disabled, the caller is responsible
1671 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1674 * Note: this is probably too low level an operation for use in drivers.
1675 * Please consult with lkml before using this in your driver.
1677 int split_free_page(struct page
*page
)
1682 order
= page_order(page
);
1684 nr_pages
= __isolate_free_page(page
, order
);
1688 /* Split into individual pages */
1689 set_page_refcounted(page
);
1690 split_page(page
, order
);
1695 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
1698 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
1699 struct zone
*zone
, unsigned int order
,
1700 gfp_t gfp_flags
, int migratetype
)
1702 unsigned long flags
;
1704 bool cold
= ((gfp_flags
& __GFP_COLD
) != 0);
1706 if (likely(order
== 0)) {
1707 struct per_cpu_pages
*pcp
;
1708 struct list_head
*list
;
1710 local_irq_save(flags
);
1711 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1712 list
= &pcp
->lists
[migratetype
];
1713 if (list_empty(list
)) {
1714 pcp
->count
+= rmqueue_bulk(zone
, 0,
1717 if (unlikely(list_empty(list
)))
1722 page
= list_entry(list
->prev
, struct page
, lru
);
1724 page
= list_entry(list
->next
, struct page
, lru
);
1726 list_del(&page
->lru
);
1729 if (unlikely(gfp_flags
& __GFP_NOFAIL
)) {
1731 * __GFP_NOFAIL is not to be used in new code.
1733 * All __GFP_NOFAIL callers should be fixed so that they
1734 * properly detect and handle allocation failures.
1736 * We most definitely don't want callers attempting to
1737 * allocate greater than order-1 page units with
1740 WARN_ON_ONCE(order
> 1);
1742 spin_lock_irqsave(&zone
->lock
, flags
);
1743 page
= __rmqueue(zone
, order
, migratetype
);
1744 spin_unlock(&zone
->lock
);
1747 __mod_zone_freepage_state(zone
, -(1 << order
),
1748 get_freepage_migratetype(page
));
1751 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
, -(1 << order
));
1752 if (atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]) <= 0 &&
1753 !test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
))
1754 set_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
1756 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
1757 zone_statistics(preferred_zone
, zone
, gfp_flags
);
1758 local_irq_restore(flags
);
1760 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
1764 local_irq_restore(flags
);
1768 #ifdef CONFIG_FAIL_PAGE_ALLOC
1771 struct fault_attr attr
;
1773 u32 ignore_gfp_highmem
;
1774 u32 ignore_gfp_wait
;
1776 } fail_page_alloc
= {
1777 .attr
= FAULT_ATTR_INITIALIZER
,
1778 .ignore_gfp_wait
= 1,
1779 .ignore_gfp_highmem
= 1,
1783 static int __init
setup_fail_page_alloc(char *str
)
1785 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
1787 __setup("fail_page_alloc=", setup_fail_page_alloc
);
1789 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1791 if (order
< fail_page_alloc
.min_order
)
1793 if (gfp_mask
& __GFP_NOFAIL
)
1795 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
1797 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
1800 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
1803 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1805 static int __init
fail_page_alloc_debugfs(void)
1807 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
1810 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
1811 &fail_page_alloc
.attr
);
1813 return PTR_ERR(dir
);
1815 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
1816 &fail_page_alloc
.ignore_gfp_wait
))
1818 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
1819 &fail_page_alloc
.ignore_gfp_highmem
))
1821 if (!debugfs_create_u32("min-order", mode
, dir
,
1822 &fail_page_alloc
.min_order
))
1827 debugfs_remove_recursive(dir
);
1832 late_initcall(fail_page_alloc_debugfs
);
1834 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1836 #else /* CONFIG_FAIL_PAGE_ALLOC */
1838 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1843 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1846 * Return true if free pages are above 'mark'. This takes into account the order
1847 * of the allocation.
1849 static bool __zone_watermark_ok(struct zone
*z
, unsigned int order
,
1850 unsigned long mark
, int classzone_idx
, int alloc_flags
,
1853 /* free_pages may go negative - that's OK */
1858 free_pages
-= (1 << order
) - 1;
1859 if (alloc_flags
& ALLOC_HIGH
)
1861 if (alloc_flags
& ALLOC_HARDER
)
1864 /* If allocation can't use CMA areas don't use free CMA pages */
1865 if (!(alloc_flags
& ALLOC_CMA
))
1866 free_cma
= zone_page_state(z
, NR_FREE_CMA_PAGES
);
1869 if (free_pages
- free_cma
<= min
+ z
->lowmem_reserve
[classzone_idx
])
1871 for (o
= 0; o
< order
; o
++) {
1872 /* At the next order, this order's pages become unavailable */
1873 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
1875 /* Require fewer higher order pages to be free */
1878 if (free_pages
<= min
)
1884 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
1885 int classzone_idx
, int alloc_flags
)
1887 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1888 zone_page_state(z
, NR_FREE_PAGES
));
1891 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
1892 unsigned long mark
, int classzone_idx
, int alloc_flags
)
1894 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
1896 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
1897 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
1899 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1905 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1906 * skip over zones that are not allowed by the cpuset, or that have
1907 * been recently (in last second) found to be nearly full. See further
1908 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1909 * that have to skip over a lot of full or unallowed zones.
1911 * If the zonelist cache is present in the passed zonelist, then
1912 * returns a pointer to the allowed node mask (either the current
1913 * tasks mems_allowed, or node_states[N_MEMORY].)
1915 * If the zonelist cache is not available for this zonelist, does
1916 * nothing and returns NULL.
1918 * If the fullzones BITMAP in the zonelist cache is stale (more than
1919 * a second since last zap'd) then we zap it out (clear its bits.)
1921 * We hold off even calling zlc_setup, until after we've checked the
1922 * first zone in the zonelist, on the theory that most allocations will
1923 * be satisfied from that first zone, so best to examine that zone as
1924 * quickly as we can.
1926 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1928 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1929 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
1931 zlc
= zonelist
->zlcache_ptr
;
1935 if (time_after(jiffies
, zlc
->last_full_zap
+ HZ
)) {
1936 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1937 zlc
->last_full_zap
= jiffies
;
1940 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
1941 &cpuset_current_mems_allowed
:
1942 &node_states
[N_MEMORY
];
1943 return allowednodes
;
1947 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1948 * if it is worth looking at further for free memory:
1949 * 1) Check that the zone isn't thought to be full (doesn't have its
1950 * bit set in the zonelist_cache fullzones BITMAP).
1951 * 2) Check that the zones node (obtained from the zonelist_cache
1952 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1953 * Return true (non-zero) if zone is worth looking at further, or
1954 * else return false (zero) if it is not.
1956 * This check -ignores- the distinction between various watermarks,
1957 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1958 * found to be full for any variation of these watermarks, it will
1959 * be considered full for up to one second by all requests, unless
1960 * we are so low on memory on all allowed nodes that we are forced
1961 * into the second scan of the zonelist.
1963 * In the second scan we ignore this zonelist cache and exactly
1964 * apply the watermarks to all zones, even it is slower to do so.
1965 * We are low on memory in the second scan, and should leave no stone
1966 * unturned looking for a free page.
1968 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1969 nodemask_t
*allowednodes
)
1971 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1972 int i
; /* index of *z in zonelist zones */
1973 int n
; /* node that zone *z is on */
1975 zlc
= zonelist
->zlcache_ptr
;
1979 i
= z
- zonelist
->_zonerefs
;
1982 /* This zone is worth trying if it is allowed but not full */
1983 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1987 * Given 'z' scanning a zonelist, set the corresponding bit in
1988 * zlc->fullzones, so that subsequent attempts to allocate a page
1989 * from that zone don't waste time re-examining it.
1991 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1993 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1994 int i
; /* index of *z in zonelist zones */
1996 zlc
= zonelist
->zlcache_ptr
;
2000 i
= z
- zonelist
->_zonerefs
;
2002 set_bit(i
, zlc
->fullzones
);
2006 * clear all zones full, called after direct reclaim makes progress so that
2007 * a zone that was recently full is not skipped over for up to a second
2009 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
2011 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
2013 zlc
= zonelist
->zlcache_ptr
;
2017 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
2020 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2022 return local_zone
->node
== zone
->node
;
2025 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2027 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <
2031 #else /* CONFIG_NUMA */
2033 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
2038 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
2039 nodemask_t
*allowednodes
)
2044 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
2048 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
2052 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2057 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2062 #endif /* CONFIG_NUMA */
2064 static void reset_alloc_batches(struct zone
*preferred_zone
)
2066 struct zone
*zone
= preferred_zone
->zone_pgdat
->node_zones
;
2069 mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
2070 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
2071 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
2072 clear_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2073 } while (zone
++ != preferred_zone
);
2077 * get_page_from_freelist goes through the zonelist trying to allocate
2080 static struct page
*
2081 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
2082 const struct alloc_context
*ac
)
2084 struct zonelist
*zonelist
= ac
->zonelist
;
2086 struct page
*page
= NULL
;
2088 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
2089 int zlc_active
= 0; /* set if using zonelist_cache */
2090 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
2091 bool consider_zone_dirty
= (alloc_flags
& ALLOC_WMARK_LOW
) &&
2092 (gfp_mask
& __GFP_WRITE
);
2093 int nr_fair_skipped
= 0;
2094 bool zonelist_rescan
;
2097 zonelist_rescan
= false;
2100 * Scan zonelist, looking for a zone with enough free.
2101 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2103 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
2107 if (IS_ENABLED(CONFIG_NUMA
) && zlc_active
&&
2108 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
2110 if (cpusets_enabled() &&
2111 (alloc_flags
& ALLOC_CPUSET
) &&
2112 !cpuset_zone_allowed(zone
, gfp_mask
))
2115 * Distribute pages in proportion to the individual
2116 * zone size to ensure fair page aging. The zone a
2117 * page was allocated in should have no effect on the
2118 * time the page has in memory before being reclaimed.
2120 if (alloc_flags
& ALLOC_FAIR
) {
2121 if (!zone_local(ac
->preferred_zone
, zone
))
2123 if (test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
)) {
2129 * When allocating a page cache page for writing, we
2130 * want to get it from a zone that is within its dirty
2131 * limit, such that no single zone holds more than its
2132 * proportional share of globally allowed dirty pages.
2133 * The dirty limits take into account the zone's
2134 * lowmem reserves and high watermark so that kswapd
2135 * should be able to balance it without having to
2136 * write pages from its LRU list.
2138 * This may look like it could increase pressure on
2139 * lower zones by failing allocations in higher zones
2140 * before they are full. But the pages that do spill
2141 * over are limited as the lower zones are protected
2142 * by this very same mechanism. It should not become
2143 * a practical burden to them.
2145 * XXX: For now, allow allocations to potentially
2146 * exceed the per-zone dirty limit in the slowpath
2147 * (ALLOC_WMARK_LOW unset) before going into reclaim,
2148 * which is important when on a NUMA setup the allowed
2149 * zones are together not big enough to reach the
2150 * global limit. The proper fix for these situations
2151 * will require awareness of zones in the
2152 * dirty-throttling and the flusher threads.
2154 if (consider_zone_dirty
&& !zone_dirty_ok(zone
))
2157 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
2158 if (!zone_watermark_ok(zone
, order
, mark
,
2159 ac
->classzone_idx
, alloc_flags
)) {
2162 /* Checked here to keep the fast path fast */
2163 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
2164 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
2167 if (IS_ENABLED(CONFIG_NUMA
) &&
2168 !did_zlc_setup
&& nr_online_nodes
> 1) {
2170 * we do zlc_setup if there are multiple nodes
2171 * and before considering the first zone allowed
2174 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
2179 if (zone_reclaim_mode
== 0 ||
2180 !zone_allows_reclaim(ac
->preferred_zone
, zone
))
2181 goto this_zone_full
;
2184 * As we may have just activated ZLC, check if the first
2185 * eligible zone has failed zone_reclaim recently.
2187 if (IS_ENABLED(CONFIG_NUMA
) && zlc_active
&&
2188 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
2191 ret
= zone_reclaim(zone
, gfp_mask
, order
);
2193 case ZONE_RECLAIM_NOSCAN
:
2196 case ZONE_RECLAIM_FULL
:
2197 /* scanned but unreclaimable */
2200 /* did we reclaim enough */
2201 if (zone_watermark_ok(zone
, order
, mark
,
2202 ac
->classzone_idx
, alloc_flags
))
2206 * Failed to reclaim enough to meet watermark.
2207 * Only mark the zone full if checking the min
2208 * watermark or if we failed to reclaim just
2209 * 1<<order pages or else the page allocator
2210 * fastpath will prematurely mark zones full
2211 * when the watermark is between the low and
2214 if (((alloc_flags
& ALLOC_WMARK_MASK
) == ALLOC_WMARK_MIN
) ||
2215 ret
== ZONE_RECLAIM_SOME
)
2216 goto this_zone_full
;
2223 page
= buffered_rmqueue(ac
->preferred_zone
, zone
, order
,
2224 gfp_mask
, ac
->migratetype
);
2226 if (prep_new_page(page
, order
, gfp_mask
, alloc_flags
))
2231 if (IS_ENABLED(CONFIG_NUMA
) && zlc_active
)
2232 zlc_mark_zone_full(zonelist
, z
);
2236 * The first pass makes sure allocations are spread fairly within the
2237 * local node. However, the local node might have free pages left
2238 * after the fairness batches are exhausted, and remote zones haven't
2239 * even been considered yet. Try once more without fairness, and
2240 * include remote zones now, before entering the slowpath and waking
2241 * kswapd: prefer spilling to a remote zone over swapping locally.
2243 if (alloc_flags
& ALLOC_FAIR
) {
2244 alloc_flags
&= ~ALLOC_FAIR
;
2245 if (nr_fair_skipped
) {
2246 zonelist_rescan
= true;
2247 reset_alloc_batches(ac
->preferred_zone
);
2249 if (nr_online_nodes
> 1)
2250 zonelist_rescan
= true;
2253 if (unlikely(IS_ENABLED(CONFIG_NUMA
) && zlc_active
)) {
2254 /* Disable zlc cache for second zonelist scan */
2256 zonelist_rescan
= true;
2259 if (zonelist_rescan
)
2266 * Large machines with many possible nodes should not always dump per-node
2267 * meminfo in irq context.
2269 static inline bool should_suppress_show_mem(void)
2274 ret
= in_interrupt();
2279 static DEFINE_RATELIMIT_STATE(nopage_rs
,
2280 DEFAULT_RATELIMIT_INTERVAL
,
2281 DEFAULT_RATELIMIT_BURST
);
2283 void warn_alloc_failed(gfp_t gfp_mask
, int order
, const char *fmt
, ...)
2285 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
2287 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
2288 debug_guardpage_minorder() > 0)
2292 * This documents exceptions given to allocations in certain
2293 * contexts that are allowed to allocate outside current's set
2296 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2297 if (test_thread_flag(TIF_MEMDIE
) ||
2298 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
2299 filter
&= ~SHOW_MEM_FILTER_NODES
;
2300 if (in_interrupt() || !(gfp_mask
& __GFP_WAIT
))
2301 filter
&= ~SHOW_MEM_FILTER_NODES
;
2304 struct va_format vaf
;
2307 va_start(args
, fmt
);
2312 pr_warn("%pV", &vaf
);
2317 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
2318 current
->comm
, order
, gfp_mask
);
2321 if (!should_suppress_show_mem())
2326 should_alloc_retry(gfp_t gfp_mask
, unsigned int order
,
2327 unsigned long did_some_progress
,
2328 unsigned long pages_reclaimed
)
2330 /* Do not loop if specifically requested */
2331 if (gfp_mask
& __GFP_NORETRY
)
2334 /* Always retry if specifically requested */
2335 if (gfp_mask
& __GFP_NOFAIL
)
2339 * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
2340 * making forward progress without invoking OOM. Suspend also disables
2341 * storage devices so kswapd will not help. Bail if we are suspending.
2343 if (!did_some_progress
&& pm_suspended_storage())
2347 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
2348 * means __GFP_NOFAIL, but that may not be true in other
2351 if (order
<= PAGE_ALLOC_COSTLY_ORDER
)
2355 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
2356 * specified, then we retry until we no longer reclaim any pages
2357 * (above), or we've reclaimed an order of pages at least as
2358 * large as the allocation's order. In both cases, if the
2359 * allocation still fails, we stop retrying.
2361 if (gfp_mask
& __GFP_REPEAT
&& pages_reclaimed
< (1 << order
))
2367 static inline struct page
*
2368 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
2369 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
2373 *did_some_progress
= 0;
2376 * Acquire the per-zone oom lock for each zone. If that
2377 * fails, somebody else is making progress for us.
2379 if (!oom_zonelist_trylock(ac
->zonelist
, gfp_mask
)) {
2380 *did_some_progress
= 1;
2381 schedule_timeout_uninterruptible(1);
2386 * Go through the zonelist yet one more time, keep very high watermark
2387 * here, this is only to catch a parallel oom killing, we must fail if
2388 * we're still under heavy pressure.
2390 page
= get_page_from_freelist(gfp_mask
| __GFP_HARDWALL
, order
,
2391 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
2395 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2396 /* Coredumps can quickly deplete all memory reserves */
2397 if (current
->flags
& PF_DUMPCORE
)
2399 /* The OOM killer will not help higher order allocs */
2400 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2402 /* The OOM killer does not needlessly kill tasks for lowmem */
2403 if (ac
->high_zoneidx
< ZONE_NORMAL
)
2405 /* The OOM killer does not compensate for light reclaim */
2406 if (!(gfp_mask
& __GFP_FS
)) {
2408 * XXX: Page reclaim didn't yield anything,
2409 * and the OOM killer can't be invoked, but
2410 * keep looping as per should_alloc_retry().
2412 *did_some_progress
= 1;
2415 /* The OOM killer may not free memory on a specific node */
2416 if (gfp_mask
& __GFP_THISNODE
)
2419 /* Exhausted what can be done so it's blamo time */
2420 if (out_of_memory(ac
->zonelist
, gfp_mask
, order
, ac
->nodemask
, false)
2421 || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
))
2422 *did_some_progress
= 1;
2424 oom_zonelist_unlock(ac
->zonelist
, gfp_mask
);
2428 #ifdef CONFIG_COMPACTION
2429 /* Try memory compaction for high-order allocations before reclaim */
2430 static struct page
*
2431 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2432 int alloc_flags
, const struct alloc_context
*ac
,
2433 enum migrate_mode mode
, int *contended_compaction
,
2434 bool *deferred_compaction
)
2436 unsigned long compact_result
;
2442 current
->flags
|= PF_MEMALLOC
;
2443 compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
2444 mode
, contended_compaction
);
2445 current
->flags
&= ~PF_MEMALLOC
;
2447 switch (compact_result
) {
2448 case COMPACT_DEFERRED
:
2449 *deferred_compaction
= true;
2451 case COMPACT_SKIPPED
:
2458 * At least in one zone compaction wasn't deferred or skipped, so let's
2459 * count a compaction stall
2461 count_vm_event(COMPACTSTALL
);
2463 page
= get_page_from_freelist(gfp_mask
, order
,
2464 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
2467 struct zone
*zone
= page_zone(page
);
2469 zone
->compact_blockskip_flush
= false;
2470 compaction_defer_reset(zone
, order
, true);
2471 count_vm_event(COMPACTSUCCESS
);
2476 * It's bad if compaction run occurs and fails. The most likely reason
2477 * is that pages exist, but not enough to satisfy watermarks.
2479 count_vm_event(COMPACTFAIL
);
2486 static inline struct page
*
2487 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2488 int alloc_flags
, const struct alloc_context
*ac
,
2489 enum migrate_mode mode
, int *contended_compaction
,
2490 bool *deferred_compaction
)
2494 #endif /* CONFIG_COMPACTION */
2496 /* Perform direct synchronous page reclaim */
2498 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
2499 const struct alloc_context
*ac
)
2501 struct reclaim_state reclaim_state
;
2506 /* We now go into synchronous reclaim */
2507 cpuset_memory_pressure_bump();
2508 current
->flags
|= PF_MEMALLOC
;
2509 lockdep_set_current_reclaim_state(gfp_mask
);
2510 reclaim_state
.reclaimed_slab
= 0;
2511 current
->reclaim_state
= &reclaim_state
;
2513 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
2516 current
->reclaim_state
= NULL
;
2517 lockdep_clear_current_reclaim_state();
2518 current
->flags
&= ~PF_MEMALLOC
;
2525 /* The really slow allocator path where we enter direct reclaim */
2526 static inline struct page
*
2527 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
2528 int alloc_flags
, const struct alloc_context
*ac
,
2529 unsigned long *did_some_progress
)
2531 struct page
*page
= NULL
;
2532 bool drained
= false;
2534 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
2535 if (unlikely(!(*did_some_progress
)))
2538 /* After successful reclaim, reconsider all zones for allocation */
2539 if (IS_ENABLED(CONFIG_NUMA
))
2540 zlc_clear_zones_full(ac
->zonelist
);
2543 page
= get_page_from_freelist(gfp_mask
, order
,
2544 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
2547 * If an allocation failed after direct reclaim, it could be because
2548 * pages are pinned on the per-cpu lists. Drain them and try again
2550 if (!page
&& !drained
) {
2551 drain_all_pages(NULL
);
2560 * This is called in the allocator slow-path if the allocation request is of
2561 * sufficient urgency to ignore watermarks and take other desperate measures
2563 static inline struct page
*
2564 __alloc_pages_high_priority(gfp_t gfp_mask
, unsigned int order
,
2565 const struct alloc_context
*ac
)
2570 page
= get_page_from_freelist(gfp_mask
, order
,
2571 ALLOC_NO_WATERMARKS
, ac
);
2573 if (!page
&& gfp_mask
& __GFP_NOFAIL
)
2574 wait_iff_congested(ac
->preferred_zone
, BLK_RW_ASYNC
,
2576 } while (!page
&& (gfp_mask
& __GFP_NOFAIL
));
2581 static void wake_all_kswapds(unsigned int order
, const struct alloc_context
*ac
)
2586 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
2587 ac
->high_zoneidx
, ac
->nodemask
)
2588 wakeup_kswapd(zone
, order
, zone_idx(ac
->preferred_zone
));
2592 gfp_to_alloc_flags(gfp_t gfp_mask
)
2594 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
2595 const bool atomic
= !(gfp_mask
& (__GFP_WAIT
| __GFP_NO_KSWAPD
));
2597 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2598 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
2601 * The caller may dip into page reserves a bit more if the caller
2602 * cannot run direct reclaim, or if the caller has realtime scheduling
2603 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2604 * set both ALLOC_HARDER (atomic == true) and ALLOC_HIGH (__GFP_HIGH).
2606 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
2610 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
2611 * if it can't schedule.
2613 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2614 alloc_flags
|= ALLOC_HARDER
;
2616 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
2617 * comment for __cpuset_node_allowed().
2619 alloc_flags
&= ~ALLOC_CPUSET
;
2620 } else if (unlikely(rt_task(current
)) && !in_interrupt())
2621 alloc_flags
|= ALLOC_HARDER
;
2623 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
2624 if (gfp_mask
& __GFP_MEMALLOC
)
2625 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2626 else if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
2627 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2628 else if (!in_interrupt() &&
2629 ((current
->flags
& PF_MEMALLOC
) ||
2630 unlikely(test_thread_flag(TIF_MEMDIE
))))
2631 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2634 if (gfpflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
2635 alloc_flags
|= ALLOC_CMA
;
2640 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
2642 return !!(gfp_to_alloc_flags(gfp_mask
) & ALLOC_NO_WATERMARKS
);
2645 static inline struct page
*
2646 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
2647 struct alloc_context
*ac
)
2649 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
2650 struct page
*page
= NULL
;
2652 unsigned long pages_reclaimed
= 0;
2653 unsigned long did_some_progress
;
2654 enum migrate_mode migration_mode
= MIGRATE_ASYNC
;
2655 bool deferred_compaction
= false;
2656 int contended_compaction
= COMPACT_CONTENDED_NONE
;
2659 * In the slowpath, we sanity check order to avoid ever trying to
2660 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2661 * be using allocators in order of preference for an area that is
2664 if (order
>= MAX_ORDER
) {
2665 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
2670 * If this allocation cannot block and it is for a specific node, then
2671 * fail early. There's no need to wakeup kswapd or retry for a
2672 * speculative node-specific allocation.
2674 if (IS_ENABLED(CONFIG_NUMA
) && (gfp_mask
& __GFP_THISNODE
) && !wait
)
2678 if (!(gfp_mask
& __GFP_NO_KSWAPD
))
2679 wake_all_kswapds(order
, ac
);
2682 * OK, we're below the kswapd watermark and have kicked background
2683 * reclaim. Now things get more complex, so set up alloc_flags according
2684 * to how we want to proceed.
2686 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
2689 * Find the true preferred zone if the allocation is unconstrained by
2692 if (!(alloc_flags
& ALLOC_CPUSET
) && !ac
->nodemask
) {
2693 struct zoneref
*preferred_zoneref
;
2694 preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
2695 ac
->high_zoneidx
, NULL
, &ac
->preferred_zone
);
2696 ac
->classzone_idx
= zonelist_zone_idx(preferred_zoneref
);
2699 /* This is the last chance, in general, before the goto nopage. */
2700 page
= get_page_from_freelist(gfp_mask
, order
,
2701 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
2705 /* Allocate without watermarks if the context allows */
2706 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
2708 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
2709 * the allocation is high priority and these type of
2710 * allocations are system rather than user orientated
2712 ac
->zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
2714 page
= __alloc_pages_high_priority(gfp_mask
, order
, ac
);
2721 /* Atomic allocations - we can't balance anything */
2724 * All existing users of the deprecated __GFP_NOFAIL are
2725 * blockable, so warn of any new users that actually allow this
2726 * type of allocation to fail.
2728 WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
);
2732 /* Avoid recursion of direct reclaim */
2733 if (current
->flags
& PF_MEMALLOC
)
2736 /* Avoid allocations with no watermarks from looping endlessly */
2737 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
2741 * Try direct compaction. The first pass is asynchronous. Subsequent
2742 * attempts after direct reclaim are synchronous
2744 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
2746 &contended_compaction
,
2747 &deferred_compaction
);
2751 /* Checks for THP-specific high-order allocations */
2752 if ((gfp_mask
& GFP_TRANSHUGE
) == GFP_TRANSHUGE
) {
2754 * If compaction is deferred for high-order allocations, it is
2755 * because sync compaction recently failed. If this is the case
2756 * and the caller requested a THP allocation, we do not want
2757 * to heavily disrupt the system, so we fail the allocation
2758 * instead of entering direct reclaim.
2760 if (deferred_compaction
)
2764 * In all zones where compaction was attempted (and not
2765 * deferred or skipped), lock contention has been detected.
2766 * For THP allocation we do not want to disrupt the others
2767 * so we fallback to base pages instead.
2769 if (contended_compaction
== COMPACT_CONTENDED_LOCK
)
2773 * If compaction was aborted due to need_resched(), we do not
2774 * want to further increase allocation latency, unless it is
2775 * khugepaged trying to collapse.
2777 if (contended_compaction
== COMPACT_CONTENDED_SCHED
2778 && !(current
->flags
& PF_KTHREAD
))
2783 * It can become very expensive to allocate transparent hugepages at
2784 * fault, so use asynchronous memory compaction for THP unless it is
2785 * khugepaged trying to collapse.
2787 if ((gfp_mask
& GFP_TRANSHUGE
) != GFP_TRANSHUGE
||
2788 (current
->flags
& PF_KTHREAD
))
2789 migration_mode
= MIGRATE_SYNC_LIGHT
;
2791 /* Try direct reclaim and then allocating */
2792 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
2793 &did_some_progress
);
2797 /* Check if we should retry the allocation */
2798 pages_reclaimed
+= did_some_progress
;
2799 if (should_alloc_retry(gfp_mask
, order
, did_some_progress
,
2802 * If we fail to make progress by freeing individual
2803 * pages, but the allocation wants us to keep going,
2804 * start OOM killing tasks.
2806 if (!did_some_progress
) {
2807 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
,
2808 &did_some_progress
);
2811 if (!did_some_progress
)
2814 /* Wait for some write requests to complete then retry */
2815 wait_iff_congested(ac
->preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2819 * High-order allocations do not necessarily loop after
2820 * direct reclaim and reclaim/compaction depends on compaction
2821 * being called after reclaim so call directly if necessary
2823 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
2824 alloc_flags
, ac
, migration_mode
,
2825 &contended_compaction
,
2826 &deferred_compaction
);
2832 warn_alloc_failed(gfp_mask
, order
, NULL
);
2838 * This is the 'heart' of the zoned buddy allocator.
2841 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
2842 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
2844 struct zoneref
*preferred_zoneref
;
2845 struct page
*page
= NULL
;
2846 unsigned int cpuset_mems_cookie
;
2847 int alloc_flags
= ALLOC_WMARK_LOW
|ALLOC_CPUSET
|ALLOC_FAIR
;
2848 gfp_t alloc_mask
; /* The gfp_t that was actually used for allocation */
2849 struct alloc_context ac
= {
2850 .high_zoneidx
= gfp_zone(gfp_mask
),
2851 .nodemask
= nodemask
,
2852 .migratetype
= gfpflags_to_migratetype(gfp_mask
),
2855 gfp_mask
&= gfp_allowed_mask
;
2857 lockdep_trace_alloc(gfp_mask
);
2859 might_sleep_if(gfp_mask
& __GFP_WAIT
);
2861 if (should_fail_alloc_page(gfp_mask
, order
))
2865 * Check the zones suitable for the gfp_mask contain at least one
2866 * valid zone. It's possible to have an empty zonelist as a result
2867 * of __GFP_THISNODE and a memoryless node
2869 if (unlikely(!zonelist
->_zonerefs
->zone
))
2872 if (IS_ENABLED(CONFIG_CMA
) && ac
.migratetype
== MIGRATE_MOVABLE
)
2873 alloc_flags
|= ALLOC_CMA
;
2876 cpuset_mems_cookie
= read_mems_allowed_begin();
2878 /* We set it here, as __alloc_pages_slowpath might have changed it */
2879 ac
.zonelist
= zonelist
;
2880 /* The preferred zone is used for statistics later */
2881 preferred_zoneref
= first_zones_zonelist(ac
.zonelist
, ac
.high_zoneidx
,
2882 ac
.nodemask
? : &cpuset_current_mems_allowed
,
2883 &ac
.preferred_zone
);
2884 if (!ac
.preferred_zone
)
2886 ac
.classzone_idx
= zonelist_zone_idx(preferred_zoneref
);
2888 /* First allocation attempt */
2889 alloc_mask
= gfp_mask
|__GFP_HARDWALL
;
2890 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
2891 if (unlikely(!page
)) {
2893 * Runtime PM, block IO and its error handling path
2894 * can deadlock because I/O on the device might not
2897 alloc_mask
= memalloc_noio_flags(gfp_mask
);
2899 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
2902 if (kmemcheck_enabled
&& page
)
2903 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
2905 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
2909 * When updating a task's mems_allowed, it is possible to race with
2910 * parallel threads in such a way that an allocation can fail while
2911 * the mask is being updated. If a page allocation is about to fail,
2912 * check if the cpuset changed during allocation and if so, retry.
2914 if (unlikely(!page
&& read_mems_allowed_retry(cpuset_mems_cookie
)))
2919 EXPORT_SYMBOL(__alloc_pages_nodemask
);
2922 * Common helper functions.
2924 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
2929 * __get_free_pages() returns a 32-bit address, which cannot represent
2932 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
2934 page
= alloc_pages(gfp_mask
, order
);
2937 return (unsigned long) page_address(page
);
2939 EXPORT_SYMBOL(__get_free_pages
);
2941 unsigned long get_zeroed_page(gfp_t gfp_mask
)
2943 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
2945 EXPORT_SYMBOL(get_zeroed_page
);
2947 void __free_pages(struct page
*page
, unsigned int order
)
2949 if (put_page_testzero(page
)) {
2951 free_hot_cold_page(page
, false);
2953 __free_pages_ok(page
, order
);
2957 EXPORT_SYMBOL(__free_pages
);
2959 void free_pages(unsigned long addr
, unsigned int order
)
2962 VM_BUG_ON(!virt_addr_valid((void *)addr
));
2963 __free_pages(virt_to_page((void *)addr
), order
);
2967 EXPORT_SYMBOL(free_pages
);
2971 * An arbitrary-length arbitrary-offset area of memory which resides
2972 * within a 0 or higher order page. Multiple fragments within that page
2973 * are individually refcounted, in the page's reference counter.
2975 * The page_frag functions below provide a simple allocation framework for
2976 * page fragments. This is used by the network stack and network device
2977 * drivers to provide a backing region of memory for use as either an
2978 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
2980 static struct page
*__page_frag_refill(struct page_frag_cache
*nc
,
2983 struct page
*page
= NULL
;
2984 gfp_t gfp
= gfp_mask
;
2986 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
2987 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
2989 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
2990 PAGE_FRAG_CACHE_MAX_ORDER
);
2991 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
2993 if (unlikely(!page
))
2994 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
2996 nc
->va
= page
? page_address(page
) : NULL
;
3001 void *__alloc_page_frag(struct page_frag_cache
*nc
,
3002 unsigned int fragsz
, gfp_t gfp_mask
)
3004 unsigned int size
= PAGE_SIZE
;
3008 if (unlikely(!nc
->va
)) {
3010 page
= __page_frag_refill(nc
, gfp_mask
);
3014 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3015 /* if size can vary use size else just use PAGE_SIZE */
3018 /* Even if we own the page, we do not use atomic_set().
3019 * This would break get_page_unless_zero() users.
3021 atomic_add(size
- 1, &page
->_count
);
3023 /* reset page count bias and offset to start of new frag */
3024 nc
->pfmemalloc
= page
->pfmemalloc
;
3025 nc
->pagecnt_bias
= size
;
3029 offset
= nc
->offset
- fragsz
;
3030 if (unlikely(offset
< 0)) {
3031 page
= virt_to_page(nc
->va
);
3033 if (!atomic_sub_and_test(nc
->pagecnt_bias
, &page
->_count
))
3036 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3037 /* if size can vary use size else just use PAGE_SIZE */
3040 /* OK, page count is 0, we can safely set it */
3041 atomic_set(&page
->_count
, size
);
3043 /* reset page count bias and offset to start of new frag */
3044 nc
->pagecnt_bias
= size
;
3045 offset
= size
- fragsz
;
3049 nc
->offset
= offset
;
3051 return nc
->va
+ offset
;
3053 EXPORT_SYMBOL(__alloc_page_frag
);
3056 * Frees a page fragment allocated out of either a compound or order 0 page.
3058 void __free_page_frag(void *addr
)
3060 struct page
*page
= virt_to_head_page(addr
);
3062 if (unlikely(put_page_testzero(page
)))
3063 __free_pages_ok(page
, compound_order(page
));
3065 EXPORT_SYMBOL(__free_page_frag
);
3068 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
3069 * of the current memory cgroup.
3071 * It should be used when the caller would like to use kmalloc, but since the
3072 * allocation is large, it has to fall back to the page allocator.
3074 struct page
*alloc_kmem_pages(gfp_t gfp_mask
, unsigned int order
)
3077 struct mem_cgroup
*memcg
= NULL
;
3079 if (!memcg_kmem_newpage_charge(gfp_mask
, &memcg
, order
))
3081 page
= alloc_pages(gfp_mask
, order
);
3082 memcg_kmem_commit_charge(page
, memcg
, order
);
3086 struct page
*alloc_kmem_pages_node(int nid
, gfp_t gfp_mask
, unsigned int order
)
3089 struct mem_cgroup
*memcg
= NULL
;
3091 if (!memcg_kmem_newpage_charge(gfp_mask
, &memcg
, order
))
3093 page
= alloc_pages_node(nid
, gfp_mask
, order
);
3094 memcg_kmem_commit_charge(page
, memcg
, order
);
3099 * __free_kmem_pages and free_kmem_pages will free pages allocated with
3102 void __free_kmem_pages(struct page
*page
, unsigned int order
)
3104 memcg_kmem_uncharge_pages(page
, order
);
3105 __free_pages(page
, order
);
3108 void free_kmem_pages(unsigned long addr
, unsigned int order
)
3111 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3112 __free_kmem_pages(virt_to_page((void *)addr
), order
);
3116 static void *make_alloc_exact(unsigned long addr
, unsigned order
, size_t size
)
3119 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
3120 unsigned long used
= addr
+ PAGE_ALIGN(size
);
3122 split_page(virt_to_page((void *)addr
), order
);
3123 while (used
< alloc_end
) {
3128 return (void *)addr
;
3132 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
3133 * @size: the number of bytes to allocate
3134 * @gfp_mask: GFP flags for the allocation
3136 * This function is similar to alloc_pages(), except that it allocates the
3137 * minimum number of pages to satisfy the request. alloc_pages() can only
3138 * allocate memory in power-of-two pages.
3140 * This function is also limited by MAX_ORDER.
3142 * Memory allocated by this function must be released by free_pages_exact().
3144 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
3146 unsigned int order
= get_order(size
);
3149 addr
= __get_free_pages(gfp_mask
, order
);
3150 return make_alloc_exact(addr
, order
, size
);
3152 EXPORT_SYMBOL(alloc_pages_exact
);
3155 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
3157 * @nid: the preferred node ID where memory should be allocated
3158 * @size: the number of bytes to allocate
3159 * @gfp_mask: GFP flags for the allocation
3161 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
3163 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
3166 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
3168 unsigned order
= get_order(size
);
3169 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
3172 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
3176 * free_pages_exact - release memory allocated via alloc_pages_exact()
3177 * @virt: the value returned by alloc_pages_exact.
3178 * @size: size of allocation, same value as passed to alloc_pages_exact().
3180 * Release the memory allocated by a previous call to alloc_pages_exact.
3182 void free_pages_exact(void *virt
, size_t size
)
3184 unsigned long addr
= (unsigned long)virt
;
3185 unsigned long end
= addr
+ PAGE_ALIGN(size
);
3187 while (addr
< end
) {
3192 EXPORT_SYMBOL(free_pages_exact
);
3195 * nr_free_zone_pages - count number of pages beyond high watermark
3196 * @offset: The zone index of the highest zone
3198 * nr_free_zone_pages() counts the number of counts pages which are beyond the
3199 * high watermark within all zones at or below a given zone index. For each
3200 * zone, the number of pages is calculated as:
3201 * managed_pages - high_pages
3203 static unsigned long nr_free_zone_pages(int offset
)
3208 /* Just pick one node, since fallback list is circular */
3209 unsigned long sum
= 0;
3211 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
3213 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
3214 unsigned long size
= zone
->managed_pages
;
3215 unsigned long high
= high_wmark_pages(zone
);
3224 * nr_free_buffer_pages - count number of pages beyond high watermark
3226 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3227 * watermark within ZONE_DMA and ZONE_NORMAL.
3229 unsigned long nr_free_buffer_pages(void)
3231 return nr_free_zone_pages(gfp_zone(GFP_USER
));
3233 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
3236 * nr_free_pagecache_pages - count number of pages beyond high watermark
3238 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3239 * high watermark within all zones.
3241 unsigned long nr_free_pagecache_pages(void)
3243 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
3246 static inline void show_node(struct zone
*zone
)
3248 if (IS_ENABLED(CONFIG_NUMA
))
3249 printk("Node %d ", zone_to_nid(zone
));
3252 void si_meminfo(struct sysinfo
*val
)
3254 val
->totalram
= totalram_pages
;
3255 val
->sharedram
= global_page_state(NR_SHMEM
);
3256 val
->freeram
= global_page_state(NR_FREE_PAGES
);
3257 val
->bufferram
= nr_blockdev_pages();
3258 val
->totalhigh
= totalhigh_pages
;
3259 val
->freehigh
= nr_free_highpages();
3260 val
->mem_unit
= PAGE_SIZE
;
3263 EXPORT_SYMBOL(si_meminfo
);
3266 void si_meminfo_node(struct sysinfo
*val
, int nid
)
3268 int zone_type
; /* needs to be signed */
3269 unsigned long managed_pages
= 0;
3270 pg_data_t
*pgdat
= NODE_DATA(nid
);
3272 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
3273 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
3274 val
->totalram
= managed_pages
;
3275 val
->sharedram
= node_page_state(nid
, NR_SHMEM
);
3276 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
3277 #ifdef CONFIG_HIGHMEM
3278 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].managed_pages
;
3279 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
3285 val
->mem_unit
= PAGE_SIZE
;
3290 * Determine whether the node should be displayed or not, depending on whether
3291 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3293 bool skip_free_areas_node(unsigned int flags
, int nid
)
3296 unsigned int cpuset_mems_cookie
;
3298 if (!(flags
& SHOW_MEM_FILTER_NODES
))
3302 cpuset_mems_cookie
= read_mems_allowed_begin();
3303 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
3304 } while (read_mems_allowed_retry(cpuset_mems_cookie
));
3309 #define K(x) ((x) << (PAGE_SHIFT-10))
3311 static void show_migration_types(unsigned char type
)
3313 static const char types
[MIGRATE_TYPES
] = {
3314 [MIGRATE_UNMOVABLE
] = 'U',
3315 [MIGRATE_RECLAIMABLE
] = 'E',
3316 [MIGRATE_MOVABLE
] = 'M',
3317 [MIGRATE_RESERVE
] = 'R',
3319 [MIGRATE_CMA
] = 'C',
3321 #ifdef CONFIG_MEMORY_ISOLATION
3322 [MIGRATE_ISOLATE
] = 'I',
3325 char tmp
[MIGRATE_TYPES
+ 1];
3329 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
3330 if (type
& (1 << i
))
3335 printk("(%s) ", tmp
);
3339 * Show free area list (used inside shift_scroll-lock stuff)
3340 * We also calculate the percentage fragmentation. We do this by counting the
3341 * memory on each free list with the exception of the first item on the list.
3344 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
3347 void show_free_areas(unsigned int filter
)
3349 unsigned long free_pcp
= 0;
3353 for_each_populated_zone(zone
) {
3354 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3357 for_each_online_cpu(cpu
)
3358 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
3361 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3362 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3363 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
3364 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3365 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3366 " free:%lu free_pcp:%lu free_cma:%lu\n",
3367 global_page_state(NR_ACTIVE_ANON
),
3368 global_page_state(NR_INACTIVE_ANON
),
3369 global_page_state(NR_ISOLATED_ANON
),
3370 global_page_state(NR_ACTIVE_FILE
),
3371 global_page_state(NR_INACTIVE_FILE
),
3372 global_page_state(NR_ISOLATED_FILE
),
3373 global_page_state(NR_UNEVICTABLE
),
3374 global_page_state(NR_FILE_DIRTY
),
3375 global_page_state(NR_WRITEBACK
),
3376 global_page_state(NR_UNSTABLE_NFS
),
3377 global_page_state(NR_SLAB_RECLAIMABLE
),
3378 global_page_state(NR_SLAB_UNRECLAIMABLE
),
3379 global_page_state(NR_FILE_MAPPED
),
3380 global_page_state(NR_SHMEM
),
3381 global_page_state(NR_PAGETABLE
),
3382 global_page_state(NR_BOUNCE
),
3383 global_page_state(NR_FREE_PAGES
),
3385 global_page_state(NR_FREE_CMA_PAGES
));
3387 for_each_populated_zone(zone
) {
3390 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3394 for_each_online_cpu(cpu
)
3395 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
3403 " active_anon:%lukB"
3404 " inactive_anon:%lukB"
3405 " active_file:%lukB"
3406 " inactive_file:%lukB"
3407 " unevictable:%lukB"
3408 " isolated(anon):%lukB"
3409 " isolated(file):%lukB"
3417 " slab_reclaimable:%lukB"
3418 " slab_unreclaimable:%lukB"
3419 " kernel_stack:%lukB"
3426 " writeback_tmp:%lukB"
3427 " pages_scanned:%lu"
3428 " all_unreclaimable? %s"
3431 K(zone_page_state(zone
, NR_FREE_PAGES
)),
3432 K(min_wmark_pages(zone
)),
3433 K(low_wmark_pages(zone
)),
3434 K(high_wmark_pages(zone
)),
3435 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
3436 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
3437 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
3438 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
3439 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
3440 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
3441 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
3442 K(zone
->present_pages
),
3443 K(zone
->managed_pages
),
3444 K(zone_page_state(zone
, NR_MLOCK
)),
3445 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
3446 K(zone_page_state(zone
, NR_WRITEBACK
)),
3447 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
3448 K(zone_page_state(zone
, NR_SHMEM
)),
3449 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
3450 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
3451 zone_page_state(zone
, NR_KERNEL_STACK
) *
3453 K(zone_page_state(zone
, NR_PAGETABLE
)),
3454 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
3455 K(zone_page_state(zone
, NR_BOUNCE
)),
3457 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
3458 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)),
3459 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
3460 K(zone_page_state(zone
, NR_PAGES_SCANNED
)),
3461 (!zone_reclaimable(zone
) ? "yes" : "no")
3463 printk("lowmem_reserve[]:");
3464 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3465 printk(" %ld", zone
->lowmem_reserve
[i
]);
3469 for_each_populated_zone(zone
) {
3470 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
3471 unsigned char types
[MAX_ORDER
];
3473 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3476 printk("%s: ", zone
->name
);
3478 spin_lock_irqsave(&zone
->lock
, flags
);
3479 for (order
= 0; order
< MAX_ORDER
; order
++) {
3480 struct free_area
*area
= &zone
->free_area
[order
];
3483 nr
[order
] = area
->nr_free
;
3484 total
+= nr
[order
] << order
;
3487 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
3488 if (!list_empty(&area
->free_list
[type
]))
3489 types
[order
] |= 1 << type
;
3492 spin_unlock_irqrestore(&zone
->lock
, flags
);
3493 for (order
= 0; order
< MAX_ORDER
; order
++) {
3494 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
3496 show_migration_types(types
[order
]);
3498 printk("= %lukB\n", K(total
));
3501 hugetlb_show_meminfo();
3503 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
3505 show_swap_cache_info();
3508 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
3510 zoneref
->zone
= zone
;
3511 zoneref
->zone_idx
= zone_idx(zone
);
3515 * Builds allocation fallback zone lists.
3517 * Add all populated zones of a node to the zonelist.
3519 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
3523 enum zone_type zone_type
= MAX_NR_ZONES
;
3527 zone
= pgdat
->node_zones
+ zone_type
;
3528 if (populated_zone(zone
)) {
3529 zoneref_set_zone(zone
,
3530 &zonelist
->_zonerefs
[nr_zones
++]);
3531 check_highest_zone(zone_type
);
3533 } while (zone_type
);
3541 * 0 = automatic detection of better ordering.
3542 * 1 = order by ([node] distance, -zonetype)
3543 * 2 = order by (-zonetype, [node] distance)
3545 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
3546 * the same zonelist. So only NUMA can configure this param.
3548 #define ZONELIST_ORDER_DEFAULT 0
3549 #define ZONELIST_ORDER_NODE 1
3550 #define ZONELIST_ORDER_ZONE 2
3552 /* zonelist order in the kernel.
3553 * set_zonelist_order() will set this to NODE or ZONE.
3555 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3556 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
3560 /* The value user specified ....changed by config */
3561 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3562 /* string for sysctl */
3563 #define NUMA_ZONELIST_ORDER_LEN 16
3564 char numa_zonelist_order
[16] = "default";
3567 * interface for configure zonelist ordering.
3568 * command line option "numa_zonelist_order"
3569 * = "[dD]efault - default, automatic configuration.
3570 * = "[nN]ode - order by node locality, then by zone within node
3571 * = "[zZ]one - order by zone, then by locality within zone
3574 static int __parse_numa_zonelist_order(char *s
)
3576 if (*s
== 'd' || *s
== 'D') {
3577 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3578 } else if (*s
== 'n' || *s
== 'N') {
3579 user_zonelist_order
= ZONELIST_ORDER_NODE
;
3580 } else if (*s
== 'z' || *s
== 'Z') {
3581 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
3584 "Ignoring invalid numa_zonelist_order value: "
3591 static __init
int setup_numa_zonelist_order(char *s
)
3598 ret
= __parse_numa_zonelist_order(s
);
3600 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
3604 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
3607 * sysctl handler for numa_zonelist_order
3609 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
3610 void __user
*buffer
, size_t *length
,
3613 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
3615 static DEFINE_MUTEX(zl_order_mutex
);
3617 mutex_lock(&zl_order_mutex
);
3619 if (strlen((char *)table
->data
) >= NUMA_ZONELIST_ORDER_LEN
) {
3623 strcpy(saved_string
, (char *)table
->data
);
3625 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
3629 int oldval
= user_zonelist_order
;
3631 ret
= __parse_numa_zonelist_order((char *)table
->data
);
3634 * bogus value. restore saved string
3636 strncpy((char *)table
->data
, saved_string
,
3637 NUMA_ZONELIST_ORDER_LEN
);
3638 user_zonelist_order
= oldval
;
3639 } else if (oldval
!= user_zonelist_order
) {
3640 mutex_lock(&zonelists_mutex
);
3641 build_all_zonelists(NULL
, NULL
);
3642 mutex_unlock(&zonelists_mutex
);
3646 mutex_unlock(&zl_order_mutex
);
3651 #define MAX_NODE_LOAD (nr_online_nodes)
3652 static int node_load
[MAX_NUMNODES
];
3655 * find_next_best_node - find the next node that should appear in a given node's fallback list
3656 * @node: node whose fallback list we're appending
3657 * @used_node_mask: nodemask_t of already used nodes
3659 * We use a number of factors to determine which is the next node that should
3660 * appear on a given node's fallback list. The node should not have appeared
3661 * already in @node's fallback list, and it should be the next closest node
3662 * according to the distance array (which contains arbitrary distance values
3663 * from each node to each node in the system), and should also prefer nodes
3664 * with no CPUs, since presumably they'll have very little allocation pressure
3665 * on them otherwise.
3666 * It returns -1 if no node is found.
3668 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
3671 int min_val
= INT_MAX
;
3672 int best_node
= NUMA_NO_NODE
;
3673 const struct cpumask
*tmp
= cpumask_of_node(0);
3675 /* Use the local node if we haven't already */
3676 if (!node_isset(node
, *used_node_mask
)) {
3677 node_set(node
, *used_node_mask
);
3681 for_each_node_state(n
, N_MEMORY
) {
3683 /* Don't want a node to appear more than once */
3684 if (node_isset(n
, *used_node_mask
))
3687 /* Use the distance array to find the distance */
3688 val
= node_distance(node
, n
);
3690 /* Penalize nodes under us ("prefer the next node") */
3693 /* Give preference to headless and unused nodes */
3694 tmp
= cpumask_of_node(n
);
3695 if (!cpumask_empty(tmp
))
3696 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
3698 /* Slight preference for less loaded node */
3699 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
3700 val
+= node_load
[n
];
3702 if (val
< min_val
) {
3709 node_set(best_node
, *used_node_mask
);
3716 * Build zonelists ordered by node and zones within node.
3717 * This results in maximum locality--normal zone overflows into local
3718 * DMA zone, if any--but risks exhausting DMA zone.
3720 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
3723 struct zonelist
*zonelist
;
3725 zonelist
= &pgdat
->node_zonelists
[0];
3726 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
3728 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
3729 zonelist
->_zonerefs
[j
].zone
= NULL
;
3730 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3734 * Build gfp_thisnode zonelists
3736 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
3739 struct zonelist
*zonelist
;
3741 zonelist
= &pgdat
->node_zonelists
[1];
3742 j
= build_zonelists_node(pgdat
, zonelist
, 0);
3743 zonelist
->_zonerefs
[j
].zone
= NULL
;
3744 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3748 * Build zonelists ordered by zone and nodes within zones.
3749 * This results in conserving DMA zone[s] until all Normal memory is
3750 * exhausted, but results in overflowing to remote node while memory
3751 * may still exist in local DMA zone.
3753 static int node_order
[MAX_NUMNODES
];
3755 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
3758 int zone_type
; /* needs to be signed */
3760 struct zonelist
*zonelist
;
3762 zonelist
= &pgdat
->node_zonelists
[0];
3764 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
3765 for (j
= 0; j
< nr_nodes
; j
++) {
3766 node
= node_order
[j
];
3767 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
3768 if (populated_zone(z
)) {
3770 &zonelist
->_zonerefs
[pos
++]);
3771 check_highest_zone(zone_type
);
3775 zonelist
->_zonerefs
[pos
].zone
= NULL
;
3776 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
3779 #if defined(CONFIG_64BIT)
3781 * Devices that require DMA32/DMA are relatively rare and do not justify a
3782 * penalty to every machine in case the specialised case applies. Default
3783 * to Node-ordering on 64-bit NUMA machines
3785 static int default_zonelist_order(void)
3787 return ZONELIST_ORDER_NODE
;
3791 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
3792 * by the kernel. If processes running on node 0 deplete the low memory zone
3793 * then reclaim will occur more frequency increasing stalls and potentially
3794 * be easier to OOM if a large percentage of the zone is under writeback or
3795 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
3796 * Hence, default to zone ordering on 32-bit.
3798 static int default_zonelist_order(void)
3800 return ZONELIST_ORDER_ZONE
;
3802 #endif /* CONFIG_64BIT */
3804 static void set_zonelist_order(void)
3806 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
3807 current_zonelist_order
= default_zonelist_order();
3809 current_zonelist_order
= user_zonelist_order
;
3812 static void build_zonelists(pg_data_t
*pgdat
)
3816 nodemask_t used_mask
;
3817 int local_node
, prev_node
;
3818 struct zonelist
*zonelist
;
3819 int order
= current_zonelist_order
;
3821 /* initialize zonelists */
3822 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
3823 zonelist
= pgdat
->node_zonelists
+ i
;
3824 zonelist
->_zonerefs
[0].zone
= NULL
;
3825 zonelist
->_zonerefs
[0].zone_idx
= 0;
3828 /* NUMA-aware ordering of nodes */
3829 local_node
= pgdat
->node_id
;
3830 load
= nr_online_nodes
;
3831 prev_node
= local_node
;
3832 nodes_clear(used_mask
);
3834 memset(node_order
, 0, sizeof(node_order
));
3837 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
3839 * We don't want to pressure a particular node.
3840 * So adding penalty to the first node in same
3841 * distance group to make it round-robin.
3843 if (node_distance(local_node
, node
) !=
3844 node_distance(local_node
, prev_node
))
3845 node_load
[node
] = load
;
3849 if (order
== ZONELIST_ORDER_NODE
)
3850 build_zonelists_in_node_order(pgdat
, node
);
3852 node_order
[j
++] = node
; /* remember order */
3855 if (order
== ZONELIST_ORDER_ZONE
) {
3856 /* calculate node order -- i.e., DMA last! */
3857 build_zonelists_in_zone_order(pgdat
, j
);
3860 build_thisnode_zonelists(pgdat
);
3863 /* Construct the zonelist performance cache - see further mmzone.h */
3864 static void build_zonelist_cache(pg_data_t
*pgdat
)
3866 struct zonelist
*zonelist
;
3867 struct zonelist_cache
*zlc
;
3870 zonelist
= &pgdat
->node_zonelists
[0];
3871 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
3872 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
3873 for (z
= zonelist
->_zonerefs
; z
->zone
; z
++)
3874 zlc
->z_to_n
[z
- zonelist
->_zonerefs
] = zonelist_node_idx(z
);
3877 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3879 * Return node id of node used for "local" allocations.
3880 * I.e., first node id of first zone in arg node's generic zonelist.
3881 * Used for initializing percpu 'numa_mem', which is used primarily
3882 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
3884 int local_memory_node(int node
)
3888 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
3889 gfp_zone(GFP_KERNEL
),
3896 #else /* CONFIG_NUMA */
3898 static void set_zonelist_order(void)
3900 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
3903 static void build_zonelists(pg_data_t
*pgdat
)
3905 int node
, local_node
;
3907 struct zonelist
*zonelist
;
3909 local_node
= pgdat
->node_id
;
3911 zonelist
= &pgdat
->node_zonelists
[0];
3912 j
= build_zonelists_node(pgdat
, zonelist
, 0);
3915 * Now we build the zonelist so that it contains the zones
3916 * of all the other nodes.
3917 * We don't want to pressure a particular node, so when
3918 * building the zones for node N, we make sure that the
3919 * zones coming right after the local ones are those from
3920 * node N+1 (modulo N)
3922 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
3923 if (!node_online(node
))
3925 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
3927 for (node
= 0; node
< local_node
; node
++) {
3928 if (!node_online(node
))
3930 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
3933 zonelist
->_zonerefs
[j
].zone
= NULL
;
3934 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3937 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3938 static void build_zonelist_cache(pg_data_t
*pgdat
)
3940 pgdat
->node_zonelists
[0].zlcache_ptr
= NULL
;
3943 #endif /* CONFIG_NUMA */
3946 * Boot pageset table. One per cpu which is going to be used for all
3947 * zones and all nodes. The parameters will be set in such a way
3948 * that an item put on a list will immediately be handed over to
3949 * the buddy list. This is safe since pageset manipulation is done
3950 * with interrupts disabled.
3952 * The boot_pagesets must be kept even after bootup is complete for
3953 * unused processors and/or zones. They do play a role for bootstrapping
3954 * hotplugged processors.
3956 * zoneinfo_show() and maybe other functions do
3957 * not check if the processor is online before following the pageset pointer.
3958 * Other parts of the kernel may not check if the zone is available.
3960 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
3961 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
3962 static void setup_zone_pageset(struct zone
*zone
);
3965 * Global mutex to protect against size modification of zonelists
3966 * as well as to serialize pageset setup for the new populated zone.
3968 DEFINE_MUTEX(zonelists_mutex
);
3970 /* return values int ....just for stop_machine() */
3971 static int __build_all_zonelists(void *data
)
3975 pg_data_t
*self
= data
;
3978 memset(node_load
, 0, sizeof(node_load
));
3981 if (self
&& !node_online(self
->node_id
)) {
3982 build_zonelists(self
);
3983 build_zonelist_cache(self
);
3986 for_each_online_node(nid
) {
3987 pg_data_t
*pgdat
= NODE_DATA(nid
);
3989 build_zonelists(pgdat
);
3990 build_zonelist_cache(pgdat
);
3994 * Initialize the boot_pagesets that are going to be used
3995 * for bootstrapping processors. The real pagesets for
3996 * each zone will be allocated later when the per cpu
3997 * allocator is available.
3999 * boot_pagesets are used also for bootstrapping offline
4000 * cpus if the system is already booted because the pagesets
4001 * are needed to initialize allocators on a specific cpu too.
4002 * F.e. the percpu allocator needs the page allocator which
4003 * needs the percpu allocator in order to allocate its pagesets
4004 * (a chicken-egg dilemma).
4006 for_each_possible_cpu(cpu
) {
4007 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
4009 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4011 * We now know the "local memory node" for each node--
4012 * i.e., the node of the first zone in the generic zonelist.
4013 * Set up numa_mem percpu variable for on-line cpus. During
4014 * boot, only the boot cpu should be on-line; we'll init the
4015 * secondary cpus' numa_mem as they come on-line. During
4016 * node/memory hotplug, we'll fixup all on-line cpus.
4018 if (cpu_online(cpu
))
4019 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
4026 static noinline
void __init
4027 build_all_zonelists_init(void)
4029 __build_all_zonelists(NULL
);
4030 mminit_verify_zonelist();
4031 cpuset_init_current_mems_allowed();
4035 * Called with zonelists_mutex held always
4036 * unless system_state == SYSTEM_BOOTING.
4038 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4039 * [we're only called with non-NULL zone through __meminit paths] and
4040 * (2) call of __init annotated helper build_all_zonelists_init
4041 * [protected by SYSTEM_BOOTING].
4043 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
4045 set_zonelist_order();
4047 if (system_state
== SYSTEM_BOOTING
) {
4048 build_all_zonelists_init();
4050 #ifdef CONFIG_MEMORY_HOTPLUG
4052 setup_zone_pageset(zone
);
4054 /* we have to stop all cpus to guarantee there is no user
4056 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
4057 /* cpuset refresh routine should be here */
4059 vm_total_pages
= nr_free_pagecache_pages();
4061 * Disable grouping by mobility if the number of pages in the
4062 * system is too low to allow the mechanism to work. It would be
4063 * more accurate, but expensive to check per-zone. This check is
4064 * made on memory-hotadd so a system can start with mobility
4065 * disabled and enable it later
4067 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
4068 page_group_by_mobility_disabled
= 1;
4070 page_group_by_mobility_disabled
= 0;
4072 pr_info("Built %i zonelists in %s order, mobility grouping %s. "
4073 "Total pages: %ld\n",
4075 zonelist_order_name
[current_zonelist_order
],
4076 page_group_by_mobility_disabled
? "off" : "on",
4079 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
4084 * Helper functions to size the waitqueue hash table.
4085 * Essentially these want to choose hash table sizes sufficiently
4086 * large so that collisions trying to wait on pages are rare.
4087 * But in fact, the number of active page waitqueues on typical
4088 * systems is ridiculously low, less than 200. So this is even
4089 * conservative, even though it seems large.
4091 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
4092 * waitqueues, i.e. the size of the waitq table given the number of pages.
4094 #define PAGES_PER_WAITQUEUE 256
4096 #ifndef CONFIG_MEMORY_HOTPLUG
4097 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
4099 unsigned long size
= 1;
4101 pages
/= PAGES_PER_WAITQUEUE
;
4103 while (size
< pages
)
4107 * Once we have dozens or even hundreds of threads sleeping
4108 * on IO we've got bigger problems than wait queue collision.
4109 * Limit the size of the wait table to a reasonable size.
4111 size
= min(size
, 4096UL);
4113 return max(size
, 4UL);
4117 * A zone's size might be changed by hot-add, so it is not possible to determine
4118 * a suitable size for its wait_table. So we use the maximum size now.
4120 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
4122 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
4123 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
4124 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
4126 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
4127 * or more by the traditional way. (See above). It equals:
4129 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
4130 * ia64(16K page size) : = ( 8G + 4M)byte.
4131 * powerpc (64K page size) : = (32G +16M)byte.
4133 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
4140 * This is an integer logarithm so that shifts can be used later
4141 * to extract the more random high bits from the multiplicative
4142 * hash function before the remainder is taken.
4144 static inline unsigned long wait_table_bits(unsigned long size
)
4150 * Check if a pageblock contains reserved pages
4152 static int pageblock_is_reserved(unsigned long start_pfn
, unsigned long end_pfn
)
4156 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
4157 if (!pfn_valid_within(pfn
) || PageReserved(pfn_to_page(pfn
)))
4164 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
4165 * of blocks reserved is based on min_wmark_pages(zone). The memory within
4166 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
4167 * higher will lead to a bigger reserve which will get freed as contiguous
4168 * blocks as reclaim kicks in
4170 static void setup_zone_migrate_reserve(struct zone
*zone
)
4172 unsigned long start_pfn
, pfn
, end_pfn
, block_end_pfn
;
4174 unsigned long block_migratetype
;
4179 * Get the start pfn, end pfn and the number of blocks to reserve
4180 * We have to be careful to be aligned to pageblock_nr_pages to
4181 * make sure that we always check pfn_valid for the first page in
4184 start_pfn
= zone
->zone_start_pfn
;
4185 end_pfn
= zone_end_pfn(zone
);
4186 start_pfn
= roundup(start_pfn
, pageblock_nr_pages
);
4187 reserve
= roundup(min_wmark_pages(zone
), pageblock_nr_pages
) >>
4191 * Reserve blocks are generally in place to help high-order atomic
4192 * allocations that are short-lived. A min_free_kbytes value that
4193 * would result in more than 2 reserve blocks for atomic allocations
4194 * is assumed to be in place to help anti-fragmentation for the
4195 * future allocation of hugepages at runtime.
4197 reserve
= min(2, reserve
);
4198 old_reserve
= zone
->nr_migrate_reserve_block
;
4200 /* When memory hot-add, we almost always need to do nothing */
4201 if (reserve
== old_reserve
)
4203 zone
->nr_migrate_reserve_block
= reserve
;
4205 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
4206 if (!pfn_valid(pfn
))
4208 page
= pfn_to_page(pfn
);
4210 /* Watch out for overlapping nodes */
4211 if (page_to_nid(page
) != zone_to_nid(zone
))
4214 block_migratetype
= get_pageblock_migratetype(page
);
4216 /* Only test what is necessary when the reserves are not met */
4219 * Blocks with reserved pages will never free, skip
4222 block_end_pfn
= min(pfn
+ pageblock_nr_pages
, end_pfn
);
4223 if (pageblock_is_reserved(pfn
, block_end_pfn
))
4226 /* If this block is reserved, account for it */
4227 if (block_migratetype
== MIGRATE_RESERVE
) {
4232 /* Suitable for reserving if this block is movable */
4233 if (block_migratetype
== MIGRATE_MOVABLE
) {
4234 set_pageblock_migratetype(page
,
4236 move_freepages_block(zone
, page
,
4241 } else if (!old_reserve
) {
4243 * At boot time we don't need to scan the whole zone
4244 * for turning off MIGRATE_RESERVE.
4250 * If the reserve is met and this is a previous reserved block,
4253 if (block_migratetype
== MIGRATE_RESERVE
) {
4254 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4255 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
4261 * Initially all pages are reserved - free ones are freed
4262 * up by free_all_bootmem() once the early boot process is
4263 * done. Non-atomic initialization, single-pass.
4265 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
4266 unsigned long start_pfn
, enum memmap_context context
)
4269 unsigned long end_pfn
= start_pfn
+ size
;
4273 if (highest_memmap_pfn
< end_pfn
- 1)
4274 highest_memmap_pfn
= end_pfn
- 1;
4276 z
= &NODE_DATA(nid
)->node_zones
[zone
];
4277 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
4279 * There can be holes in boot-time mem_map[]s
4280 * handed to this function. They do not
4281 * exist on hotplugged memory.
4283 if (context
== MEMMAP_EARLY
) {
4284 if (!early_pfn_valid(pfn
))
4286 if (!early_pfn_in_nid(pfn
, nid
))
4289 page
= pfn_to_page(pfn
);
4290 set_page_links(page
, zone
, nid
, pfn
);
4291 mminit_verify_page_links(page
, zone
, nid
, pfn
);
4292 init_page_count(page
);
4293 page_mapcount_reset(page
);
4294 page_cpupid_reset_last(page
);
4295 SetPageReserved(page
);
4297 * Mark the block movable so that blocks are reserved for
4298 * movable at startup. This will force kernel allocations
4299 * to reserve their blocks rather than leaking throughout
4300 * the address space during boot when many long-lived
4301 * kernel allocations are made. Later some blocks near
4302 * the start are marked MIGRATE_RESERVE by
4303 * setup_zone_migrate_reserve()
4305 * bitmap is created for zone's valid pfn range. but memmap
4306 * can be created for invalid pages (for alignment)
4307 * check here not to call set_pageblock_migratetype() against
4310 if ((z
->zone_start_pfn
<= pfn
)
4311 && (pfn
< zone_end_pfn(z
))
4312 && !(pfn
& (pageblock_nr_pages
- 1)))
4313 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4315 INIT_LIST_HEAD(&page
->lru
);
4316 #ifdef WANT_PAGE_VIRTUAL
4317 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
4318 if (!is_highmem_idx(zone
))
4319 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
4324 static void __meminit
zone_init_free_lists(struct zone
*zone
)
4326 unsigned int order
, t
;
4327 for_each_migratetype_order(order
, t
) {
4328 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
4329 zone
->free_area
[order
].nr_free
= 0;
4333 #ifndef __HAVE_ARCH_MEMMAP_INIT
4334 #define memmap_init(size, nid, zone, start_pfn) \
4335 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4338 static int zone_batchsize(struct zone
*zone
)
4344 * The per-cpu-pages pools are set to around 1000th of the
4345 * size of the zone. But no more than 1/2 of a meg.
4347 * OK, so we don't know how big the cache is. So guess.
4349 batch
= zone
->managed_pages
/ 1024;
4350 if (batch
* PAGE_SIZE
> 512 * 1024)
4351 batch
= (512 * 1024) / PAGE_SIZE
;
4352 batch
/= 4; /* We effectively *= 4 below */
4357 * Clamp the batch to a 2^n - 1 value. Having a power
4358 * of 2 value was found to be more likely to have
4359 * suboptimal cache aliasing properties in some cases.
4361 * For example if 2 tasks are alternately allocating
4362 * batches of pages, one task can end up with a lot
4363 * of pages of one half of the possible page colors
4364 * and the other with pages of the other colors.
4366 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
4371 /* The deferral and batching of frees should be suppressed under NOMMU
4374 * The problem is that NOMMU needs to be able to allocate large chunks
4375 * of contiguous memory as there's no hardware page translation to
4376 * assemble apparent contiguous memory from discontiguous pages.
4378 * Queueing large contiguous runs of pages for batching, however,
4379 * causes the pages to actually be freed in smaller chunks. As there
4380 * can be a significant delay between the individual batches being
4381 * recycled, this leads to the once large chunks of space being
4382 * fragmented and becoming unavailable for high-order allocations.
4389 * pcp->high and pcp->batch values are related and dependent on one another:
4390 * ->batch must never be higher then ->high.
4391 * The following function updates them in a safe manner without read side
4394 * Any new users of pcp->batch and pcp->high should ensure they can cope with
4395 * those fields changing asynchronously (acording the the above rule).
4397 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
4398 * outside of boot time (or some other assurance that no concurrent updaters
4401 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
4402 unsigned long batch
)
4404 /* start with a fail safe value for batch */
4408 /* Update high, then batch, in order */
4415 /* a companion to pageset_set_high() */
4416 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
4418 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
4421 static void pageset_init(struct per_cpu_pageset
*p
)
4423 struct per_cpu_pages
*pcp
;
4426 memset(p
, 0, sizeof(*p
));
4430 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
4431 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
4434 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
4437 pageset_set_batch(p
, batch
);
4441 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
4442 * to the value high for the pageset p.
4444 static void pageset_set_high(struct per_cpu_pageset
*p
,
4447 unsigned long batch
= max(1UL, high
/ 4);
4448 if ((high
/ 4) > (PAGE_SHIFT
* 8))
4449 batch
= PAGE_SHIFT
* 8;
4451 pageset_update(&p
->pcp
, high
, batch
);
4454 static void pageset_set_high_and_batch(struct zone
*zone
,
4455 struct per_cpu_pageset
*pcp
)
4457 if (percpu_pagelist_fraction
)
4458 pageset_set_high(pcp
,
4459 (zone
->managed_pages
/
4460 percpu_pagelist_fraction
));
4462 pageset_set_batch(pcp
, zone_batchsize(zone
));
4465 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
4467 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
4470 pageset_set_high_and_batch(zone
, pcp
);
4473 static void __meminit
setup_zone_pageset(struct zone
*zone
)
4476 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
4477 for_each_possible_cpu(cpu
)
4478 zone_pageset_init(zone
, cpu
);
4482 * Allocate per cpu pagesets and initialize them.
4483 * Before this call only boot pagesets were available.
4485 void __init
setup_per_cpu_pageset(void)
4489 for_each_populated_zone(zone
)
4490 setup_zone_pageset(zone
);
4493 static noinline __init_refok
4494 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
4500 * The per-page waitqueue mechanism uses hashed waitqueues
4503 zone
->wait_table_hash_nr_entries
=
4504 wait_table_hash_nr_entries(zone_size_pages
);
4505 zone
->wait_table_bits
=
4506 wait_table_bits(zone
->wait_table_hash_nr_entries
);
4507 alloc_size
= zone
->wait_table_hash_nr_entries
4508 * sizeof(wait_queue_head_t
);
4510 if (!slab_is_available()) {
4511 zone
->wait_table
= (wait_queue_head_t
*)
4512 memblock_virt_alloc_node_nopanic(
4513 alloc_size
, zone
->zone_pgdat
->node_id
);
4516 * This case means that a zone whose size was 0 gets new memory
4517 * via memory hot-add.
4518 * But it may be the case that a new node was hot-added. In
4519 * this case vmalloc() will not be able to use this new node's
4520 * memory - this wait_table must be initialized to use this new
4521 * node itself as well.
4522 * To use this new node's memory, further consideration will be
4525 zone
->wait_table
= vmalloc(alloc_size
);
4527 if (!zone
->wait_table
)
4530 for (i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
4531 init_waitqueue_head(zone
->wait_table
+ i
);
4536 static __meminit
void zone_pcp_init(struct zone
*zone
)
4539 * per cpu subsystem is not up at this point. The following code
4540 * relies on the ability of the linker to provide the
4541 * offset of a (static) per cpu variable into the per cpu area.
4543 zone
->pageset
= &boot_pageset
;
4545 if (populated_zone(zone
))
4546 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
4547 zone
->name
, zone
->present_pages
,
4548 zone_batchsize(zone
));
4551 int __meminit
init_currently_empty_zone(struct zone
*zone
,
4552 unsigned long zone_start_pfn
,
4554 enum memmap_context context
)
4556 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
4558 ret
= zone_wait_table_init(zone
, size
);
4561 pgdat
->nr_zones
= zone_idx(zone
) + 1;
4563 zone
->zone_start_pfn
= zone_start_pfn
;
4565 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
4566 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4568 (unsigned long)zone_idx(zone
),
4569 zone_start_pfn
, (zone_start_pfn
+ size
));
4571 zone_init_free_lists(zone
);
4576 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4577 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4579 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4581 int __meminit
__early_pfn_to_nid(unsigned long pfn
)
4583 unsigned long start_pfn
, end_pfn
;
4586 * NOTE: The following SMP-unsafe globals are only used early in boot
4587 * when the kernel is running single-threaded.
4589 static unsigned long __meminitdata last_start_pfn
, last_end_pfn
;
4590 static int __meminitdata last_nid
;
4592 if (last_start_pfn
<= pfn
&& pfn
< last_end_pfn
)
4595 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
4597 last_start_pfn
= start_pfn
;
4598 last_end_pfn
= end_pfn
;
4604 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
4606 int __meminit
early_pfn_to_nid(unsigned long pfn
)
4610 nid
= __early_pfn_to_nid(pfn
);
4613 /* just returns 0 */
4617 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
4618 bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
4622 nid
= __early_pfn_to_nid(pfn
);
4623 if (nid
>= 0 && nid
!= node
)
4630 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
4631 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
4632 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
4634 * If an architecture guarantees that all ranges registered contain no holes
4635 * and may be freed, this this function may be used instead of calling
4636 * memblock_free_early_nid() manually.
4638 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
4640 unsigned long start_pfn
, end_pfn
;
4643 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
4644 start_pfn
= min(start_pfn
, max_low_pfn
);
4645 end_pfn
= min(end_pfn
, max_low_pfn
);
4647 if (start_pfn
< end_pfn
)
4648 memblock_free_early_nid(PFN_PHYS(start_pfn
),
4649 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
4655 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4656 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4658 * If an architecture guarantees that all ranges registered contain no holes and may
4659 * be freed, this function may be used instead of calling memory_present() manually.
4661 void __init
sparse_memory_present_with_active_regions(int nid
)
4663 unsigned long start_pfn
, end_pfn
;
4666 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
4667 memory_present(this_nid
, start_pfn
, end_pfn
);
4671 * get_pfn_range_for_nid - Return the start and end page frames for a node
4672 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4673 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
4674 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
4676 * It returns the start and end page frame of a node based on information
4677 * provided by memblock_set_node(). If called for a node
4678 * with no available memory, a warning is printed and the start and end
4681 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
4682 unsigned long *start_pfn
, unsigned long *end_pfn
)
4684 unsigned long this_start_pfn
, this_end_pfn
;
4690 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
4691 *start_pfn
= min(*start_pfn
, this_start_pfn
);
4692 *end_pfn
= max(*end_pfn
, this_end_pfn
);
4695 if (*start_pfn
== -1UL)
4700 * This finds a zone that can be used for ZONE_MOVABLE pages. The
4701 * assumption is made that zones within a node are ordered in monotonic
4702 * increasing memory addresses so that the "highest" populated zone is used
4704 static void __init
find_usable_zone_for_movable(void)
4707 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
4708 if (zone_index
== ZONE_MOVABLE
)
4711 if (arch_zone_highest_possible_pfn
[zone_index
] >
4712 arch_zone_lowest_possible_pfn
[zone_index
])
4716 VM_BUG_ON(zone_index
== -1);
4717 movable_zone
= zone_index
;
4721 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4722 * because it is sized independent of architecture. Unlike the other zones,
4723 * the starting point for ZONE_MOVABLE is not fixed. It may be different
4724 * in each node depending on the size of each node and how evenly kernelcore
4725 * is distributed. This helper function adjusts the zone ranges
4726 * provided by the architecture for a given node by using the end of the
4727 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4728 * zones within a node are in order of monotonic increases memory addresses
4730 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
4731 unsigned long zone_type
,
4732 unsigned long node_start_pfn
,
4733 unsigned long node_end_pfn
,
4734 unsigned long *zone_start_pfn
,
4735 unsigned long *zone_end_pfn
)
4737 /* Only adjust if ZONE_MOVABLE is on this node */
4738 if (zone_movable_pfn
[nid
]) {
4739 /* Size ZONE_MOVABLE */
4740 if (zone_type
== ZONE_MOVABLE
) {
4741 *zone_start_pfn
= zone_movable_pfn
[nid
];
4742 *zone_end_pfn
= min(node_end_pfn
,
4743 arch_zone_highest_possible_pfn
[movable_zone
]);
4745 /* Adjust for ZONE_MOVABLE starting within this range */
4746 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
4747 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
4748 *zone_end_pfn
= zone_movable_pfn
[nid
];
4750 /* Check if this whole range is within ZONE_MOVABLE */
4751 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
4752 *zone_start_pfn
= *zone_end_pfn
;
4757 * Return the number of pages a zone spans in a node, including holes
4758 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4760 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4761 unsigned long zone_type
,
4762 unsigned long node_start_pfn
,
4763 unsigned long node_end_pfn
,
4764 unsigned long *ignored
)
4766 unsigned long zone_start_pfn
, zone_end_pfn
;
4768 /* Get the start and end of the zone */
4769 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
4770 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
4771 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4772 node_start_pfn
, node_end_pfn
,
4773 &zone_start_pfn
, &zone_end_pfn
);
4775 /* Check that this node has pages within the zone's required range */
4776 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
4779 /* Move the zone boundaries inside the node if necessary */
4780 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
4781 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
4783 /* Return the spanned pages */
4784 return zone_end_pfn
- zone_start_pfn
;
4788 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4789 * then all holes in the requested range will be accounted for.
4791 unsigned long __meminit
__absent_pages_in_range(int nid
,
4792 unsigned long range_start_pfn
,
4793 unsigned long range_end_pfn
)
4795 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
4796 unsigned long start_pfn
, end_pfn
;
4799 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
4800 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
4801 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
4802 nr_absent
-= end_pfn
- start_pfn
;
4808 * absent_pages_in_range - Return number of page frames in holes within a range
4809 * @start_pfn: The start PFN to start searching for holes
4810 * @end_pfn: The end PFN to stop searching for holes
4812 * It returns the number of pages frames in memory holes within a range.
4814 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
4815 unsigned long end_pfn
)
4817 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
4820 /* Return the number of page frames in holes in a zone on a node */
4821 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4822 unsigned long zone_type
,
4823 unsigned long node_start_pfn
,
4824 unsigned long node_end_pfn
,
4825 unsigned long *ignored
)
4827 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
4828 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
4829 unsigned long zone_start_pfn
, zone_end_pfn
;
4831 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
4832 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
4834 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4835 node_start_pfn
, node_end_pfn
,
4836 &zone_start_pfn
, &zone_end_pfn
);
4837 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
4840 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4841 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4842 unsigned long zone_type
,
4843 unsigned long node_start_pfn
,
4844 unsigned long node_end_pfn
,
4845 unsigned long *zones_size
)
4847 return zones_size
[zone_type
];
4850 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4851 unsigned long zone_type
,
4852 unsigned long node_start_pfn
,
4853 unsigned long node_end_pfn
,
4854 unsigned long *zholes_size
)
4859 return zholes_size
[zone_type
];
4862 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4864 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
4865 unsigned long node_start_pfn
,
4866 unsigned long node_end_pfn
,
4867 unsigned long *zones_size
,
4868 unsigned long *zholes_size
)
4870 unsigned long realtotalpages
, totalpages
= 0;
4873 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4874 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
4878 pgdat
->node_spanned_pages
= totalpages
;
4880 realtotalpages
= totalpages
;
4881 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4883 zone_absent_pages_in_node(pgdat
->node_id
, i
,
4884 node_start_pfn
, node_end_pfn
,
4886 pgdat
->node_present_pages
= realtotalpages
;
4887 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
4891 #ifndef CONFIG_SPARSEMEM
4893 * Calculate the size of the zone->blockflags rounded to an unsigned long
4894 * Start by making sure zonesize is a multiple of pageblock_order by rounding
4895 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4896 * round what is now in bits to nearest long in bits, then return it in
4899 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
4901 unsigned long usemapsize
;
4903 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
4904 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
4905 usemapsize
= usemapsize
>> pageblock_order
;
4906 usemapsize
*= NR_PAGEBLOCK_BITS
;
4907 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
4909 return usemapsize
/ 8;
4912 static void __init
setup_usemap(struct pglist_data
*pgdat
,
4914 unsigned long zone_start_pfn
,
4915 unsigned long zonesize
)
4917 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
4918 zone
->pageblock_flags
= NULL
;
4920 zone
->pageblock_flags
=
4921 memblock_virt_alloc_node_nopanic(usemapsize
,
4925 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
4926 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
4927 #endif /* CONFIG_SPARSEMEM */
4929 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4931 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4932 void __paginginit
set_pageblock_order(void)
4936 /* Check that pageblock_nr_pages has not already been setup */
4937 if (pageblock_order
)
4940 if (HPAGE_SHIFT
> PAGE_SHIFT
)
4941 order
= HUGETLB_PAGE_ORDER
;
4943 order
= MAX_ORDER
- 1;
4946 * Assume the largest contiguous order of interest is a huge page.
4947 * This value may be variable depending on boot parameters on IA64 and
4950 pageblock_order
= order
;
4952 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4955 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4956 * is unused as pageblock_order is set at compile-time. See
4957 * include/linux/pageblock-flags.h for the values of pageblock_order based on
4960 void __paginginit
set_pageblock_order(void)
4964 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4966 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
4967 unsigned long present_pages
)
4969 unsigned long pages
= spanned_pages
;
4972 * Provide a more accurate estimation if there are holes within
4973 * the zone and SPARSEMEM is in use. If there are holes within the
4974 * zone, each populated memory region may cost us one or two extra
4975 * memmap pages due to alignment because memmap pages for each
4976 * populated regions may not naturally algined on page boundary.
4977 * So the (present_pages >> 4) heuristic is a tradeoff for that.
4979 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
4980 IS_ENABLED(CONFIG_SPARSEMEM
))
4981 pages
= present_pages
;
4983 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
4987 * Set up the zone data structures:
4988 * - mark all pages reserved
4989 * - mark all memory queues empty
4990 * - clear the memory bitmaps
4992 * NOTE: pgdat should get zeroed by caller.
4994 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
,
4995 unsigned long node_start_pfn
, unsigned long node_end_pfn
,
4996 unsigned long *zones_size
, unsigned long *zholes_size
)
4999 int nid
= pgdat
->node_id
;
5000 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
5003 pgdat_resize_init(pgdat
);
5004 #ifdef CONFIG_NUMA_BALANCING
5005 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
5006 pgdat
->numabalancing_migrate_nr_pages
= 0;
5007 pgdat
->numabalancing_migrate_next_window
= jiffies
;
5009 init_waitqueue_head(&pgdat
->kswapd_wait
);
5010 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
5011 pgdat_page_ext_init(pgdat
);
5013 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5014 struct zone
*zone
= pgdat
->node_zones
+ j
;
5015 unsigned long size
, realsize
, freesize
, memmap_pages
;
5017 size
= zone_spanned_pages_in_node(nid
, j
, node_start_pfn
,
5018 node_end_pfn
, zones_size
);
5019 realsize
= freesize
= size
- zone_absent_pages_in_node(nid
, j
,
5025 * Adjust freesize so that it accounts for how much memory
5026 * is used by this zone for memmap. This affects the watermark
5027 * and per-cpu initialisations
5029 memmap_pages
= calc_memmap_size(size
, realsize
);
5030 if (!is_highmem_idx(j
)) {
5031 if (freesize
>= memmap_pages
) {
5032 freesize
-= memmap_pages
;
5035 " %s zone: %lu pages used for memmap\n",
5036 zone_names
[j
], memmap_pages
);
5039 " %s zone: %lu pages exceeds freesize %lu\n",
5040 zone_names
[j
], memmap_pages
, freesize
);
5043 /* Account for reserved pages */
5044 if (j
== 0 && freesize
> dma_reserve
) {
5045 freesize
-= dma_reserve
;
5046 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
5047 zone_names
[0], dma_reserve
);
5050 if (!is_highmem_idx(j
))
5051 nr_kernel_pages
+= freesize
;
5052 /* Charge for highmem memmap if there are enough kernel pages */
5053 else if (nr_kernel_pages
> memmap_pages
* 2)
5054 nr_kernel_pages
-= memmap_pages
;
5055 nr_all_pages
+= freesize
;
5057 zone
->spanned_pages
= size
;
5058 zone
->present_pages
= realsize
;
5060 * Set an approximate value for lowmem here, it will be adjusted
5061 * when the bootmem allocator frees pages into the buddy system.
5062 * And all highmem pages will be managed by the buddy system.
5064 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
5067 zone
->min_unmapped_pages
= (freesize
*sysctl_min_unmapped_ratio
)
5069 zone
->min_slab_pages
= (freesize
* sysctl_min_slab_ratio
) / 100;
5071 zone
->name
= zone_names
[j
];
5072 spin_lock_init(&zone
->lock
);
5073 spin_lock_init(&zone
->lru_lock
);
5074 zone_seqlock_init(zone
);
5075 zone
->zone_pgdat
= pgdat
;
5076 zone_pcp_init(zone
);
5078 /* For bootup, initialized properly in watermark setup */
5079 mod_zone_page_state(zone
, NR_ALLOC_BATCH
, zone
->managed_pages
);
5081 lruvec_init(&zone
->lruvec
);
5085 set_pageblock_order();
5086 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
5087 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
5088 size
, MEMMAP_EARLY
);
5090 memmap_init(size
, nid
, j
, zone_start_pfn
);
5091 zone_start_pfn
+= size
;
5095 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
5097 /* Skip empty nodes */
5098 if (!pgdat
->node_spanned_pages
)
5101 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5102 /* ia64 gets its own node_mem_map, before this, without bootmem */
5103 if (!pgdat
->node_mem_map
) {
5104 unsigned long size
, start
, end
;
5108 * The zone's endpoints aren't required to be MAX_ORDER
5109 * aligned but the node_mem_map endpoints must be in order
5110 * for the buddy allocator to function correctly.
5112 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
5113 end
= pgdat_end_pfn(pgdat
);
5114 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
5115 size
= (end
- start
) * sizeof(struct page
);
5116 map
= alloc_remap(pgdat
->node_id
, size
);
5118 map
= memblock_virt_alloc_node_nopanic(size
,
5120 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
5122 #ifndef CONFIG_NEED_MULTIPLE_NODES
5124 * With no DISCONTIG, the global mem_map is just set as node 0's
5126 if (pgdat
== NODE_DATA(0)) {
5127 mem_map
= NODE_DATA(0)->node_mem_map
;
5128 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5129 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
5130 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
5131 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5134 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
5137 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
5138 unsigned long node_start_pfn
, unsigned long *zholes_size
)
5140 pg_data_t
*pgdat
= NODE_DATA(nid
);
5141 unsigned long start_pfn
= 0;
5142 unsigned long end_pfn
= 0;
5144 /* pg_data_t should be reset to zero when it's allocated */
5145 WARN_ON(pgdat
->nr_zones
|| pgdat
->classzone_idx
);
5147 pgdat
->node_id
= nid
;
5148 pgdat
->node_start_pfn
= node_start_pfn
;
5149 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5150 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
5151 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
5152 (u64
)start_pfn
<< PAGE_SHIFT
, ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
5154 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
5155 zones_size
, zholes_size
);
5157 alloc_node_mem_map(pgdat
);
5158 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5159 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
5160 nid
, (unsigned long)pgdat
,
5161 (unsigned long)pgdat
->node_mem_map
);
5164 free_area_init_core(pgdat
, start_pfn
, end_pfn
,
5165 zones_size
, zholes_size
);
5168 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5170 #if MAX_NUMNODES > 1
5172 * Figure out the number of possible node ids.
5174 void __init
setup_nr_node_ids(void)
5177 unsigned int highest
= 0;
5179 for_each_node_mask(node
, node_possible_map
)
5181 nr_node_ids
= highest
+ 1;
5186 * node_map_pfn_alignment - determine the maximum internode alignment
5188 * This function should be called after node map is populated and sorted.
5189 * It calculates the maximum power of two alignment which can distinguish
5192 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5193 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5194 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5195 * shifted, 1GiB is enough and this function will indicate so.
5197 * This is used to test whether pfn -> nid mapping of the chosen memory
5198 * model has fine enough granularity to avoid incorrect mapping for the
5199 * populated node map.
5201 * Returns the determined alignment in pfn's. 0 if there is no alignment
5202 * requirement (single node).
5204 unsigned long __init
node_map_pfn_alignment(void)
5206 unsigned long accl_mask
= 0, last_end
= 0;
5207 unsigned long start
, end
, mask
;
5211 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
5212 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
5219 * Start with a mask granular enough to pin-point to the
5220 * start pfn and tick off bits one-by-one until it becomes
5221 * too coarse to separate the current node from the last.
5223 mask
= ~((1 << __ffs(start
)) - 1);
5224 while (mask
&& last_end
<= (start
& (mask
<< 1)))
5227 /* accumulate all internode masks */
5231 /* convert mask to number of pages */
5232 return ~accl_mask
+ 1;
5235 /* Find the lowest pfn for a node */
5236 static unsigned long __init
find_min_pfn_for_node(int nid
)
5238 unsigned long min_pfn
= ULONG_MAX
;
5239 unsigned long start_pfn
;
5242 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
5243 min_pfn
= min(min_pfn
, start_pfn
);
5245 if (min_pfn
== ULONG_MAX
) {
5247 "Could not find start_pfn for node %d\n", nid
);
5255 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5257 * It returns the minimum PFN based on information provided via
5258 * memblock_set_node().
5260 unsigned long __init
find_min_pfn_with_active_regions(void)
5262 return find_min_pfn_for_node(MAX_NUMNODES
);
5266 * early_calculate_totalpages()
5267 * Sum pages in active regions for movable zone.
5268 * Populate N_MEMORY for calculating usable_nodes.
5270 static unsigned long __init
early_calculate_totalpages(void)
5272 unsigned long totalpages
= 0;
5273 unsigned long start_pfn
, end_pfn
;
5276 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
5277 unsigned long pages
= end_pfn
- start_pfn
;
5279 totalpages
+= pages
;
5281 node_set_state(nid
, N_MEMORY
);
5287 * Find the PFN the Movable zone begins in each node. Kernel memory
5288 * is spread evenly between nodes as long as the nodes have enough
5289 * memory. When they don't, some nodes will have more kernelcore than
5292 static void __init
find_zone_movable_pfns_for_nodes(void)
5295 unsigned long usable_startpfn
;
5296 unsigned long kernelcore_node
, kernelcore_remaining
;
5297 /* save the state before borrow the nodemask */
5298 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
5299 unsigned long totalpages
= early_calculate_totalpages();
5300 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
5301 struct memblock_region
*r
;
5303 /* Need to find movable_zone earlier when movable_node is specified. */
5304 find_usable_zone_for_movable();
5307 * If movable_node is specified, ignore kernelcore and movablecore
5310 if (movable_node_is_enabled()) {
5311 for_each_memblock(memory
, r
) {
5312 if (!memblock_is_hotpluggable(r
))
5317 usable_startpfn
= PFN_DOWN(r
->base
);
5318 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
5319 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
5327 * If movablecore=nn[KMG] was specified, calculate what size of
5328 * kernelcore that corresponds so that memory usable for
5329 * any allocation type is evenly spread. If both kernelcore
5330 * and movablecore are specified, then the value of kernelcore
5331 * will be used for required_kernelcore if it's greater than
5332 * what movablecore would have allowed.
5334 if (required_movablecore
) {
5335 unsigned long corepages
;
5338 * Round-up so that ZONE_MOVABLE is at least as large as what
5339 * was requested by the user
5341 required_movablecore
=
5342 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
5343 corepages
= totalpages
- required_movablecore
;
5345 required_kernelcore
= max(required_kernelcore
, corepages
);
5348 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
5349 if (!required_kernelcore
)
5352 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
5353 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
5356 /* Spread kernelcore memory as evenly as possible throughout nodes */
5357 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5358 for_each_node_state(nid
, N_MEMORY
) {
5359 unsigned long start_pfn
, end_pfn
;
5362 * Recalculate kernelcore_node if the division per node
5363 * now exceeds what is necessary to satisfy the requested
5364 * amount of memory for the kernel
5366 if (required_kernelcore
< kernelcore_node
)
5367 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5370 * As the map is walked, we track how much memory is usable
5371 * by the kernel using kernelcore_remaining. When it is
5372 * 0, the rest of the node is usable by ZONE_MOVABLE
5374 kernelcore_remaining
= kernelcore_node
;
5376 /* Go through each range of PFNs within this node */
5377 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5378 unsigned long size_pages
;
5380 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
5381 if (start_pfn
>= end_pfn
)
5384 /* Account for what is only usable for kernelcore */
5385 if (start_pfn
< usable_startpfn
) {
5386 unsigned long kernel_pages
;
5387 kernel_pages
= min(end_pfn
, usable_startpfn
)
5390 kernelcore_remaining
-= min(kernel_pages
,
5391 kernelcore_remaining
);
5392 required_kernelcore
-= min(kernel_pages
,
5393 required_kernelcore
);
5395 /* Continue if range is now fully accounted */
5396 if (end_pfn
<= usable_startpfn
) {
5399 * Push zone_movable_pfn to the end so
5400 * that if we have to rebalance
5401 * kernelcore across nodes, we will
5402 * not double account here
5404 zone_movable_pfn
[nid
] = end_pfn
;
5407 start_pfn
= usable_startpfn
;
5411 * The usable PFN range for ZONE_MOVABLE is from
5412 * start_pfn->end_pfn. Calculate size_pages as the
5413 * number of pages used as kernelcore
5415 size_pages
= end_pfn
- start_pfn
;
5416 if (size_pages
> kernelcore_remaining
)
5417 size_pages
= kernelcore_remaining
;
5418 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
5421 * Some kernelcore has been met, update counts and
5422 * break if the kernelcore for this node has been
5425 required_kernelcore
-= min(required_kernelcore
,
5427 kernelcore_remaining
-= size_pages
;
5428 if (!kernelcore_remaining
)
5434 * If there is still required_kernelcore, we do another pass with one
5435 * less node in the count. This will push zone_movable_pfn[nid] further
5436 * along on the nodes that still have memory until kernelcore is
5440 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
5444 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5445 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
5446 zone_movable_pfn
[nid
] =
5447 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
5450 /* restore the node_state */
5451 node_states
[N_MEMORY
] = saved_node_state
;
5454 /* Any regular or high memory on that node ? */
5455 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
5457 enum zone_type zone_type
;
5459 if (N_MEMORY
== N_NORMAL_MEMORY
)
5462 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
5463 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
5464 if (populated_zone(zone
)) {
5465 node_set_state(nid
, N_HIGH_MEMORY
);
5466 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
5467 zone_type
<= ZONE_NORMAL
)
5468 node_set_state(nid
, N_NORMAL_MEMORY
);
5475 * free_area_init_nodes - Initialise all pg_data_t and zone data
5476 * @max_zone_pfn: an array of max PFNs for each zone
5478 * This will call free_area_init_node() for each active node in the system.
5479 * Using the page ranges provided by memblock_set_node(), the size of each
5480 * zone in each node and their holes is calculated. If the maximum PFN
5481 * between two adjacent zones match, it is assumed that the zone is empty.
5482 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
5483 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
5484 * starts where the previous one ended. For example, ZONE_DMA32 starts
5485 * at arch_max_dma_pfn.
5487 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
5489 unsigned long start_pfn
, end_pfn
;
5492 /* Record where the zone boundaries are */
5493 memset(arch_zone_lowest_possible_pfn
, 0,
5494 sizeof(arch_zone_lowest_possible_pfn
));
5495 memset(arch_zone_highest_possible_pfn
, 0,
5496 sizeof(arch_zone_highest_possible_pfn
));
5497 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
5498 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
5499 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
5500 if (i
== ZONE_MOVABLE
)
5502 arch_zone_lowest_possible_pfn
[i
] =
5503 arch_zone_highest_possible_pfn
[i
-1];
5504 arch_zone_highest_possible_pfn
[i
] =
5505 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
5507 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
5508 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
5510 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
5511 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
5512 find_zone_movable_pfns_for_nodes();
5514 /* Print out the zone ranges */
5515 pr_info("Zone ranges:\n");
5516 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5517 if (i
== ZONE_MOVABLE
)
5519 pr_info(" %-8s ", zone_names
[i
]);
5520 if (arch_zone_lowest_possible_pfn
[i
] ==
5521 arch_zone_highest_possible_pfn
[i
])
5524 pr_cont("[mem %#018Lx-%#018Lx]\n",
5525 (u64
)arch_zone_lowest_possible_pfn
[i
]
5527 ((u64
)arch_zone_highest_possible_pfn
[i
]
5528 << PAGE_SHIFT
) - 1);
5531 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
5532 pr_info("Movable zone start for each node\n");
5533 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
5534 if (zone_movable_pfn
[i
])
5535 pr_info(" Node %d: %#018Lx\n", i
,
5536 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
5539 /* Print out the early node map */
5540 pr_info("Early memory node ranges\n");
5541 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
5542 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
5543 (u64
)start_pfn
<< PAGE_SHIFT
,
5544 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
5546 /* Initialise every node */
5547 mminit_verify_pageflags_layout();
5548 setup_nr_node_ids();
5549 for_each_online_node(nid
) {
5550 pg_data_t
*pgdat
= NODE_DATA(nid
);
5551 free_area_init_node(nid
, NULL
,
5552 find_min_pfn_for_node(nid
), NULL
);
5554 /* Any memory on that node */
5555 if (pgdat
->node_present_pages
)
5556 node_set_state(nid
, N_MEMORY
);
5557 check_for_memory(pgdat
, nid
);
5561 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
5563 unsigned long long coremem
;
5567 coremem
= memparse(p
, &p
);
5568 *core
= coremem
>> PAGE_SHIFT
;
5570 /* Paranoid check that UL is enough for the coremem value */
5571 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
5577 * kernelcore=size sets the amount of memory for use for allocations that
5578 * cannot be reclaimed or migrated.
5580 static int __init
cmdline_parse_kernelcore(char *p
)
5582 return cmdline_parse_core(p
, &required_kernelcore
);
5586 * movablecore=size sets the amount of memory for use for allocations that
5587 * can be reclaimed or migrated.
5589 static int __init
cmdline_parse_movablecore(char *p
)
5591 return cmdline_parse_core(p
, &required_movablecore
);
5594 early_param("kernelcore", cmdline_parse_kernelcore
);
5595 early_param("movablecore", cmdline_parse_movablecore
);
5597 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5599 void adjust_managed_page_count(struct page
*page
, long count
)
5601 spin_lock(&managed_page_count_lock
);
5602 page_zone(page
)->managed_pages
+= count
;
5603 totalram_pages
+= count
;
5604 #ifdef CONFIG_HIGHMEM
5605 if (PageHighMem(page
))
5606 totalhigh_pages
+= count
;
5608 spin_unlock(&managed_page_count_lock
);
5610 EXPORT_SYMBOL(adjust_managed_page_count
);
5612 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
5615 unsigned long pages
= 0;
5617 start
= (void *)PAGE_ALIGN((unsigned long)start
);
5618 end
= (void *)((unsigned long)end
& PAGE_MASK
);
5619 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
5620 if ((unsigned int)poison
<= 0xFF)
5621 memset(pos
, poison
, PAGE_SIZE
);
5622 free_reserved_page(virt_to_page(pos
));
5626 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
5627 s
, pages
<< (PAGE_SHIFT
- 10), start
, end
);
5631 EXPORT_SYMBOL(free_reserved_area
);
5633 #ifdef CONFIG_HIGHMEM
5634 void free_highmem_page(struct page
*page
)
5636 __free_reserved_page(page
);
5638 page_zone(page
)->managed_pages
++;
5644 void __init
mem_init_print_info(const char *str
)
5646 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
5647 unsigned long init_code_size
, init_data_size
;
5649 physpages
= get_num_physpages();
5650 codesize
= _etext
- _stext
;
5651 datasize
= _edata
- _sdata
;
5652 rosize
= __end_rodata
- __start_rodata
;
5653 bss_size
= __bss_stop
- __bss_start
;
5654 init_data_size
= __init_end
- __init_begin
;
5655 init_code_size
= _einittext
- _sinittext
;
5658 * Detect special cases and adjust section sizes accordingly:
5659 * 1) .init.* may be embedded into .data sections
5660 * 2) .init.text.* may be out of [__init_begin, __init_end],
5661 * please refer to arch/tile/kernel/vmlinux.lds.S.
5662 * 3) .rodata.* may be embedded into .text or .data sections.
5664 #define adj_init_size(start, end, size, pos, adj) \
5666 if (start <= pos && pos < end && size > adj) \
5670 adj_init_size(__init_begin
, __init_end
, init_data_size
,
5671 _sinittext
, init_code_size
);
5672 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
5673 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
5674 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
5675 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
5677 #undef adj_init_size
5679 pr_info("Memory: %luK/%luK available "
5680 "(%luK kernel code, %luK rwdata, %luK rodata, "
5681 "%luK init, %luK bss, %luK reserved, %luK cma-reserved"
5682 #ifdef CONFIG_HIGHMEM
5686 nr_free_pages() << (PAGE_SHIFT
-10), physpages
<< (PAGE_SHIFT
-10),
5687 codesize
>> 10, datasize
>> 10, rosize
>> 10,
5688 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
5689 (physpages
- totalram_pages
- totalcma_pages
) << (PAGE_SHIFT
-10),
5690 totalcma_pages
<< (PAGE_SHIFT
-10),
5691 #ifdef CONFIG_HIGHMEM
5692 totalhigh_pages
<< (PAGE_SHIFT
-10),
5694 str
? ", " : "", str
? str
: "");
5698 * set_dma_reserve - set the specified number of pages reserved in the first zone
5699 * @new_dma_reserve: The number of pages to mark reserved
5701 * The per-cpu batchsize and zone watermarks are determined by present_pages.
5702 * In the DMA zone, a significant percentage may be consumed by kernel image
5703 * and other unfreeable allocations which can skew the watermarks badly. This
5704 * function may optionally be used to account for unfreeable pages in the
5705 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
5706 * smaller per-cpu batchsize.
5708 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
5710 dma_reserve
= new_dma_reserve
;
5713 void __init
free_area_init(unsigned long *zones_size
)
5715 free_area_init_node(0, zones_size
,
5716 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
5719 static int page_alloc_cpu_notify(struct notifier_block
*self
,
5720 unsigned long action
, void *hcpu
)
5722 int cpu
= (unsigned long)hcpu
;
5724 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
5725 lru_add_drain_cpu(cpu
);
5729 * Spill the event counters of the dead processor
5730 * into the current processors event counters.
5731 * This artificially elevates the count of the current
5734 vm_events_fold_cpu(cpu
);
5737 * Zero the differential counters of the dead processor
5738 * so that the vm statistics are consistent.
5740 * This is only okay since the processor is dead and cannot
5741 * race with what we are doing.
5743 cpu_vm_stats_fold(cpu
);
5748 void __init
page_alloc_init(void)
5750 hotcpu_notifier(page_alloc_cpu_notify
, 0);
5754 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
5755 * or min_free_kbytes changes.
5757 static void calculate_totalreserve_pages(void)
5759 struct pglist_data
*pgdat
;
5760 unsigned long reserve_pages
= 0;
5761 enum zone_type i
, j
;
5763 for_each_online_pgdat(pgdat
) {
5764 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5765 struct zone
*zone
= pgdat
->node_zones
+ i
;
5768 /* Find valid and maximum lowmem_reserve in the zone */
5769 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
5770 if (zone
->lowmem_reserve
[j
] > max
)
5771 max
= zone
->lowmem_reserve
[j
];
5774 /* we treat the high watermark as reserved pages. */
5775 max
+= high_wmark_pages(zone
);
5777 if (max
> zone
->managed_pages
)
5778 max
= zone
->managed_pages
;
5779 reserve_pages
+= max
;
5781 * Lowmem reserves are not available to
5782 * GFP_HIGHUSER page cache allocations and
5783 * kswapd tries to balance zones to their high
5784 * watermark. As a result, neither should be
5785 * regarded as dirtyable memory, to prevent a
5786 * situation where reclaim has to clean pages
5787 * in order to balance the zones.
5789 zone
->dirty_balance_reserve
= max
;
5792 dirty_balance_reserve
= reserve_pages
;
5793 totalreserve_pages
= reserve_pages
;
5797 * setup_per_zone_lowmem_reserve - called whenever
5798 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
5799 * has a correct pages reserved value, so an adequate number of
5800 * pages are left in the zone after a successful __alloc_pages().
5802 static void setup_per_zone_lowmem_reserve(void)
5804 struct pglist_data
*pgdat
;
5805 enum zone_type j
, idx
;
5807 for_each_online_pgdat(pgdat
) {
5808 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5809 struct zone
*zone
= pgdat
->node_zones
+ j
;
5810 unsigned long managed_pages
= zone
->managed_pages
;
5812 zone
->lowmem_reserve
[j
] = 0;
5816 struct zone
*lower_zone
;
5820 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
5821 sysctl_lowmem_reserve_ratio
[idx
] = 1;
5823 lower_zone
= pgdat
->node_zones
+ idx
;
5824 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
5825 sysctl_lowmem_reserve_ratio
[idx
];
5826 managed_pages
+= lower_zone
->managed_pages
;
5831 /* update totalreserve_pages */
5832 calculate_totalreserve_pages();
5835 static void __setup_per_zone_wmarks(void)
5837 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
5838 unsigned long lowmem_pages
= 0;
5840 unsigned long flags
;
5842 /* Calculate total number of !ZONE_HIGHMEM pages */
5843 for_each_zone(zone
) {
5844 if (!is_highmem(zone
))
5845 lowmem_pages
+= zone
->managed_pages
;
5848 for_each_zone(zone
) {
5851 spin_lock_irqsave(&zone
->lock
, flags
);
5852 tmp
= (u64
)pages_min
* zone
->managed_pages
;
5853 do_div(tmp
, lowmem_pages
);
5854 if (is_highmem(zone
)) {
5856 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
5857 * need highmem pages, so cap pages_min to a small
5860 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
5861 * deltas control asynch page reclaim, and so should
5862 * not be capped for highmem.
5864 unsigned long min_pages
;
5866 min_pages
= zone
->managed_pages
/ 1024;
5867 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
5868 zone
->watermark
[WMARK_MIN
] = min_pages
;
5871 * If it's a lowmem zone, reserve a number of pages
5872 * proportionate to the zone's size.
5874 zone
->watermark
[WMARK_MIN
] = tmp
;
5877 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + (tmp
>> 2);
5878 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + (tmp
>> 1);
5880 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
5881 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
5882 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
5884 setup_zone_migrate_reserve(zone
);
5885 spin_unlock_irqrestore(&zone
->lock
, flags
);
5888 /* update totalreserve_pages */
5889 calculate_totalreserve_pages();
5893 * setup_per_zone_wmarks - called when min_free_kbytes changes
5894 * or when memory is hot-{added|removed}
5896 * Ensures that the watermark[min,low,high] values for each zone are set
5897 * correctly with respect to min_free_kbytes.
5899 void setup_per_zone_wmarks(void)
5901 mutex_lock(&zonelists_mutex
);
5902 __setup_per_zone_wmarks();
5903 mutex_unlock(&zonelists_mutex
);
5907 * The inactive anon list should be small enough that the VM never has to
5908 * do too much work, but large enough that each inactive page has a chance
5909 * to be referenced again before it is swapped out.
5911 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
5912 * INACTIVE_ANON pages on this zone's LRU, maintained by the
5913 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
5914 * the anonymous pages are kept on the inactive list.
5917 * memory ratio inactive anon
5918 * -------------------------------------
5927 static void __meminit
calculate_zone_inactive_ratio(struct zone
*zone
)
5929 unsigned int gb
, ratio
;
5931 /* Zone size in gigabytes */
5932 gb
= zone
->managed_pages
>> (30 - PAGE_SHIFT
);
5934 ratio
= int_sqrt(10 * gb
);
5938 zone
->inactive_ratio
= ratio
;
5941 static void __meminit
setup_per_zone_inactive_ratio(void)
5946 calculate_zone_inactive_ratio(zone
);
5950 * Initialise min_free_kbytes.
5952 * For small machines we want it small (128k min). For large machines
5953 * we want it large (64MB max). But it is not linear, because network
5954 * bandwidth does not increase linearly with machine size. We use
5956 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
5957 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
5973 int __meminit
init_per_zone_wmark_min(void)
5975 unsigned long lowmem_kbytes
;
5976 int new_min_free_kbytes
;
5978 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
5979 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
5981 if (new_min_free_kbytes
> user_min_free_kbytes
) {
5982 min_free_kbytes
= new_min_free_kbytes
;
5983 if (min_free_kbytes
< 128)
5984 min_free_kbytes
= 128;
5985 if (min_free_kbytes
> 65536)
5986 min_free_kbytes
= 65536;
5988 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
5989 new_min_free_kbytes
, user_min_free_kbytes
);
5991 setup_per_zone_wmarks();
5992 refresh_zone_stat_thresholds();
5993 setup_per_zone_lowmem_reserve();
5994 setup_per_zone_inactive_ratio();
5997 module_init(init_per_zone_wmark_min
)
6000 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6001 * that we can call two helper functions whenever min_free_kbytes
6004 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
6005 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6009 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6014 user_min_free_kbytes
= min_free_kbytes
;
6015 setup_per_zone_wmarks();
6021 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6022 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6027 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6032 zone
->min_unmapped_pages
= (zone
->managed_pages
*
6033 sysctl_min_unmapped_ratio
) / 100;
6037 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6038 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6043 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6048 zone
->min_slab_pages
= (zone
->managed_pages
*
6049 sysctl_min_slab_ratio
) / 100;
6055 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6056 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6057 * whenever sysctl_lowmem_reserve_ratio changes.
6059 * The reserve ratio obviously has absolutely no relation with the
6060 * minimum watermarks. The lowmem reserve ratio can only make sense
6061 * if in function of the boot time zone sizes.
6063 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6064 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6066 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6067 setup_per_zone_lowmem_reserve();
6072 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6073 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6074 * pagelist can have before it gets flushed back to buddy allocator.
6076 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
6077 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6080 int old_percpu_pagelist_fraction
;
6083 mutex_lock(&pcp_batch_high_lock
);
6084 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
6086 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6087 if (!write
|| ret
< 0)
6090 /* Sanity checking to avoid pcp imbalance */
6091 if (percpu_pagelist_fraction
&&
6092 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
6093 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
6099 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
6102 for_each_populated_zone(zone
) {
6105 for_each_possible_cpu(cpu
)
6106 pageset_set_high_and_batch(zone
,
6107 per_cpu_ptr(zone
->pageset
, cpu
));
6110 mutex_unlock(&pcp_batch_high_lock
);
6114 int hashdist
= HASHDIST_DEFAULT
;
6117 static int __init
set_hashdist(char *str
)
6121 hashdist
= simple_strtoul(str
, &str
, 0);
6124 __setup("hashdist=", set_hashdist
);
6128 * allocate a large system hash table from bootmem
6129 * - it is assumed that the hash table must contain an exact power-of-2
6130 * quantity of entries
6131 * - limit is the number of hash buckets, not the total allocation size
6133 void *__init
alloc_large_system_hash(const char *tablename
,
6134 unsigned long bucketsize
,
6135 unsigned long numentries
,
6138 unsigned int *_hash_shift
,
6139 unsigned int *_hash_mask
,
6140 unsigned long low_limit
,
6141 unsigned long high_limit
)
6143 unsigned long long max
= high_limit
;
6144 unsigned long log2qty
, size
;
6147 /* allow the kernel cmdline to have a say */
6149 /* round applicable memory size up to nearest megabyte */
6150 numentries
= nr_kernel_pages
;
6152 /* It isn't necessary when PAGE_SIZE >= 1MB */
6153 if (PAGE_SHIFT
< 20)
6154 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
6156 /* limit to 1 bucket per 2^scale bytes of low memory */
6157 if (scale
> PAGE_SHIFT
)
6158 numentries
>>= (scale
- PAGE_SHIFT
);
6160 numentries
<<= (PAGE_SHIFT
- scale
);
6162 /* Make sure we've got at least a 0-order allocation.. */
6163 if (unlikely(flags
& HASH_SMALL
)) {
6164 /* Makes no sense without HASH_EARLY */
6165 WARN_ON(!(flags
& HASH_EARLY
));
6166 if (!(numentries
>> *_hash_shift
)) {
6167 numentries
= 1UL << *_hash_shift
;
6168 BUG_ON(!numentries
);
6170 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
6171 numentries
= PAGE_SIZE
/ bucketsize
;
6173 numentries
= roundup_pow_of_two(numentries
);
6175 /* limit allocation size to 1/16 total memory by default */
6177 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
6178 do_div(max
, bucketsize
);
6180 max
= min(max
, 0x80000000ULL
);
6182 if (numentries
< low_limit
)
6183 numentries
= low_limit
;
6184 if (numentries
> max
)
6187 log2qty
= ilog2(numentries
);
6190 size
= bucketsize
<< log2qty
;
6191 if (flags
& HASH_EARLY
)
6192 table
= memblock_virt_alloc_nopanic(size
, 0);
6194 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
6197 * If bucketsize is not a power-of-two, we may free
6198 * some pages at the end of hash table which
6199 * alloc_pages_exact() automatically does
6201 if (get_order(size
) < MAX_ORDER
) {
6202 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
6203 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
6206 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
6209 panic("Failed to allocate %s hash table\n", tablename
);
6211 printk(KERN_INFO
"%s hash table entries: %ld (order: %d, %lu bytes)\n",
6214 ilog2(size
) - PAGE_SHIFT
,
6218 *_hash_shift
= log2qty
;
6220 *_hash_mask
= (1 << log2qty
) - 1;
6225 /* Return a pointer to the bitmap storing bits affecting a block of pages */
6226 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
6229 #ifdef CONFIG_SPARSEMEM
6230 return __pfn_to_section(pfn
)->pageblock_flags
;
6232 return zone
->pageblock_flags
;
6233 #endif /* CONFIG_SPARSEMEM */
6236 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
6238 #ifdef CONFIG_SPARSEMEM
6239 pfn
&= (PAGES_PER_SECTION
-1);
6240 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6242 pfn
= pfn
- round_down(zone
->zone_start_pfn
, pageblock_nr_pages
);
6243 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6244 #endif /* CONFIG_SPARSEMEM */
6248 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
6249 * @page: The page within the block of interest
6250 * @pfn: The target page frame number
6251 * @end_bitidx: The last bit of interest to retrieve
6252 * @mask: mask of bits that the caller is interested in
6254 * Return: pageblock_bits flags
6256 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
6257 unsigned long end_bitidx
,
6261 unsigned long *bitmap
;
6262 unsigned long bitidx
, word_bitidx
;
6265 zone
= page_zone(page
);
6266 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6267 bitidx
= pfn_to_bitidx(zone
, pfn
);
6268 word_bitidx
= bitidx
/ BITS_PER_LONG
;
6269 bitidx
&= (BITS_PER_LONG
-1);
6271 word
= bitmap
[word_bitidx
];
6272 bitidx
+= end_bitidx
;
6273 return (word
>> (BITS_PER_LONG
- bitidx
- 1)) & mask
;
6277 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
6278 * @page: The page within the block of interest
6279 * @flags: The flags to set
6280 * @pfn: The target page frame number
6281 * @end_bitidx: The last bit of interest
6282 * @mask: mask of bits that the caller is interested in
6284 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
6286 unsigned long end_bitidx
,
6290 unsigned long *bitmap
;
6291 unsigned long bitidx
, word_bitidx
;
6292 unsigned long old_word
, word
;
6294 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
6296 zone
= page_zone(page
);
6297 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6298 bitidx
= pfn_to_bitidx(zone
, pfn
);
6299 word_bitidx
= bitidx
/ BITS_PER_LONG
;
6300 bitidx
&= (BITS_PER_LONG
-1);
6302 VM_BUG_ON_PAGE(!zone_spans_pfn(zone
, pfn
), page
);
6304 bitidx
+= end_bitidx
;
6305 mask
<<= (BITS_PER_LONG
- bitidx
- 1);
6306 flags
<<= (BITS_PER_LONG
- bitidx
- 1);
6308 word
= READ_ONCE(bitmap
[word_bitidx
]);
6310 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
6311 if (word
== old_word
)
6318 * This function checks whether pageblock includes unmovable pages or not.
6319 * If @count is not zero, it is okay to include less @count unmovable pages
6321 * PageLRU check without isolation or lru_lock could race so that
6322 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6323 * expect this function should be exact.
6325 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
6326 bool skip_hwpoisoned_pages
)
6328 unsigned long pfn
, iter
, found
;
6332 * For avoiding noise data, lru_add_drain_all() should be called
6333 * If ZONE_MOVABLE, the zone never contains unmovable pages
6335 if (zone_idx(zone
) == ZONE_MOVABLE
)
6337 mt
= get_pageblock_migratetype(page
);
6338 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
6341 pfn
= page_to_pfn(page
);
6342 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
6343 unsigned long check
= pfn
+ iter
;
6345 if (!pfn_valid_within(check
))
6348 page
= pfn_to_page(check
);
6351 * Hugepages are not in LRU lists, but they're movable.
6352 * We need not scan over tail pages bacause we don't
6353 * handle each tail page individually in migration.
6355 if (PageHuge(page
)) {
6356 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
6361 * We can't use page_count without pin a page
6362 * because another CPU can free compound page.
6363 * This check already skips compound tails of THP
6364 * because their page->_count is zero at all time.
6366 if (!atomic_read(&page
->_count
)) {
6367 if (PageBuddy(page
))
6368 iter
+= (1 << page_order(page
)) - 1;
6373 * The HWPoisoned page may be not in buddy system, and
6374 * page_count() is not 0.
6376 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
6382 * If there are RECLAIMABLE pages, we need to check
6383 * it. But now, memory offline itself doesn't call
6384 * shrink_node_slabs() and it still to be fixed.
6387 * If the page is not RAM, page_count()should be 0.
6388 * we don't need more check. This is an _used_ not-movable page.
6390 * The problematic thing here is PG_reserved pages. PG_reserved
6391 * is set to both of a memory hole page and a _used_ kernel
6400 bool is_pageblock_removable_nolock(struct page
*page
)
6406 * We have to be careful here because we are iterating over memory
6407 * sections which are not zone aware so we might end up outside of
6408 * the zone but still within the section.
6409 * We have to take care about the node as well. If the node is offline
6410 * its NODE_DATA will be NULL - see page_zone.
6412 if (!node_online(page_to_nid(page
)))
6415 zone
= page_zone(page
);
6416 pfn
= page_to_pfn(page
);
6417 if (!zone_spans_pfn(zone
, pfn
))
6420 return !has_unmovable_pages(zone
, page
, 0, true);
6425 static unsigned long pfn_max_align_down(unsigned long pfn
)
6427 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6428 pageblock_nr_pages
) - 1);
6431 static unsigned long pfn_max_align_up(unsigned long pfn
)
6433 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6434 pageblock_nr_pages
));
6437 /* [start, end) must belong to a single zone. */
6438 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
6439 unsigned long start
, unsigned long end
)
6441 /* This function is based on compact_zone() from compaction.c. */
6442 unsigned long nr_reclaimed
;
6443 unsigned long pfn
= start
;
6444 unsigned int tries
= 0;
6449 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
6450 if (fatal_signal_pending(current
)) {
6455 if (list_empty(&cc
->migratepages
)) {
6456 cc
->nr_migratepages
= 0;
6457 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
6463 } else if (++tries
== 5) {
6464 ret
= ret
< 0 ? ret
: -EBUSY
;
6468 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
6470 cc
->nr_migratepages
-= nr_reclaimed
;
6472 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
6473 NULL
, 0, cc
->mode
, MR_CMA
);
6476 putback_movable_pages(&cc
->migratepages
);
6483 * alloc_contig_range() -- tries to allocate given range of pages
6484 * @start: start PFN to allocate
6485 * @end: one-past-the-last PFN to allocate
6486 * @migratetype: migratetype of the underlaying pageblocks (either
6487 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
6488 * in range must have the same migratetype and it must
6489 * be either of the two.
6491 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
6492 * aligned, however it's the caller's responsibility to guarantee that
6493 * we are the only thread that changes migrate type of pageblocks the
6496 * The PFN range must belong to a single zone.
6498 * Returns zero on success or negative error code. On success all
6499 * pages which PFN is in [start, end) are allocated for the caller and
6500 * need to be freed with free_contig_range().
6502 int alloc_contig_range(unsigned long start
, unsigned long end
,
6503 unsigned migratetype
)
6505 unsigned long outer_start
, outer_end
;
6508 struct compact_control cc
= {
6509 .nr_migratepages
= 0,
6511 .zone
= page_zone(pfn_to_page(start
)),
6512 .mode
= MIGRATE_SYNC
,
6513 .ignore_skip_hint
= true,
6515 INIT_LIST_HEAD(&cc
.migratepages
);
6518 * What we do here is we mark all pageblocks in range as
6519 * MIGRATE_ISOLATE. Because pageblock and max order pages may
6520 * have different sizes, and due to the way page allocator
6521 * work, we align the range to biggest of the two pages so
6522 * that page allocator won't try to merge buddies from
6523 * different pageblocks and change MIGRATE_ISOLATE to some
6524 * other migration type.
6526 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
6527 * migrate the pages from an unaligned range (ie. pages that
6528 * we are interested in). This will put all the pages in
6529 * range back to page allocator as MIGRATE_ISOLATE.
6531 * When this is done, we take the pages in range from page
6532 * allocator removing them from the buddy system. This way
6533 * page allocator will never consider using them.
6535 * This lets us mark the pageblocks back as
6536 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
6537 * aligned range but not in the unaligned, original range are
6538 * put back to page allocator so that buddy can use them.
6541 ret
= start_isolate_page_range(pfn_max_align_down(start
),
6542 pfn_max_align_up(end
), migratetype
,
6547 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
6552 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
6553 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
6554 * more, all pages in [start, end) are free in page allocator.
6555 * What we are going to do is to allocate all pages from
6556 * [start, end) (that is remove them from page allocator).
6558 * The only problem is that pages at the beginning and at the
6559 * end of interesting range may be not aligned with pages that
6560 * page allocator holds, ie. they can be part of higher order
6561 * pages. Because of this, we reserve the bigger range and
6562 * once this is done free the pages we are not interested in.
6564 * We don't have to hold zone->lock here because the pages are
6565 * isolated thus they won't get removed from buddy.
6568 lru_add_drain_all();
6569 drain_all_pages(cc
.zone
);
6572 outer_start
= start
;
6573 while (!PageBuddy(pfn_to_page(outer_start
))) {
6574 if (++order
>= MAX_ORDER
) {
6578 outer_start
&= ~0UL << order
;
6581 /* Make sure the range is really isolated. */
6582 if (test_pages_isolated(outer_start
, end
, false)) {
6583 pr_info("%s: [%lx, %lx) PFNs busy\n",
6584 __func__
, outer_start
, end
);
6589 /* Grab isolated pages from freelists. */
6590 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
6596 /* Free head and tail (if any) */
6597 if (start
!= outer_start
)
6598 free_contig_range(outer_start
, start
- outer_start
);
6599 if (end
!= outer_end
)
6600 free_contig_range(end
, outer_end
- end
);
6603 undo_isolate_page_range(pfn_max_align_down(start
),
6604 pfn_max_align_up(end
), migratetype
);
6608 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
6610 unsigned int count
= 0;
6612 for (; nr_pages
--; pfn
++) {
6613 struct page
*page
= pfn_to_page(pfn
);
6615 count
+= page_count(page
) != 1;
6618 WARN(count
!= 0, "%d pages are still in use!\n", count
);
6622 #ifdef CONFIG_MEMORY_HOTPLUG
6624 * The zone indicated has a new number of managed_pages; batch sizes and percpu
6625 * page high values need to be recalulated.
6627 void __meminit
zone_pcp_update(struct zone
*zone
)
6630 mutex_lock(&pcp_batch_high_lock
);
6631 for_each_possible_cpu(cpu
)
6632 pageset_set_high_and_batch(zone
,
6633 per_cpu_ptr(zone
->pageset
, cpu
));
6634 mutex_unlock(&pcp_batch_high_lock
);
6638 void zone_pcp_reset(struct zone
*zone
)
6640 unsigned long flags
;
6642 struct per_cpu_pageset
*pset
;
6644 /* avoid races with drain_pages() */
6645 local_irq_save(flags
);
6646 if (zone
->pageset
!= &boot_pageset
) {
6647 for_each_online_cpu(cpu
) {
6648 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
6649 drain_zonestat(zone
, pset
);
6651 free_percpu(zone
->pageset
);
6652 zone
->pageset
= &boot_pageset
;
6654 local_irq_restore(flags
);
6657 #ifdef CONFIG_MEMORY_HOTREMOVE
6659 * All pages in the range must be isolated before calling this.
6662 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
6666 unsigned int order
, i
;
6668 unsigned long flags
;
6669 /* find the first valid pfn */
6670 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
6675 zone
= page_zone(pfn_to_page(pfn
));
6676 spin_lock_irqsave(&zone
->lock
, flags
);
6678 while (pfn
< end_pfn
) {
6679 if (!pfn_valid(pfn
)) {
6683 page
= pfn_to_page(pfn
);
6685 * The HWPoisoned page may be not in buddy system, and
6686 * page_count() is not 0.
6688 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
6690 SetPageReserved(page
);
6694 BUG_ON(page_count(page
));
6695 BUG_ON(!PageBuddy(page
));
6696 order
= page_order(page
);
6697 #ifdef CONFIG_DEBUG_VM
6698 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
6699 pfn
, 1 << order
, end_pfn
);
6701 list_del(&page
->lru
);
6702 rmv_page_order(page
);
6703 zone
->free_area
[order
].nr_free
--;
6704 for (i
= 0; i
< (1 << order
); i
++)
6705 SetPageReserved((page
+i
));
6706 pfn
+= (1 << order
);
6708 spin_unlock_irqrestore(&zone
->lock
, flags
);
6712 #ifdef CONFIG_MEMORY_FAILURE
6713 bool is_free_buddy_page(struct page
*page
)
6715 struct zone
*zone
= page_zone(page
);
6716 unsigned long pfn
= page_to_pfn(page
);
6717 unsigned long flags
;
6720 spin_lock_irqsave(&zone
->lock
, flags
);
6721 for (order
= 0; order
< MAX_ORDER
; order
++) {
6722 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
6724 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
6727 spin_unlock_irqrestore(&zone
->lock
, flags
);
6729 return order
< MAX_ORDER
;