2 * linux/mm/page_alloc.c
4 * Manages the free list, the system allocates free pages here.
5 * Note that kmalloc() lives in slab.c
7 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
8 * Swap reorganised 29.12.95, Stephen Tweedie
9 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
10 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
11 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
12 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000
13 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
14 * (lots of bits borrowed from Ingo Molnar & Andrew Morton)
17 #include <linux/stddef.h>
19 #include <linux/swap.h>
20 #include <linux/interrupt.h>
21 #include <linux/pagemap.h>
22 #include <linux/jiffies.h>
23 #include <linux/bootmem.h>
24 #include <linux/memblock.h>
25 #include <linux/compiler.h>
26 #include <linux/kernel.h>
27 #include <linux/kmemcheck.h>
28 #include <linux/module.h>
29 #include <linux/suspend.h>
30 #include <linux/pagevec.h>
31 #include <linux/blkdev.h>
32 #include <linux/slab.h>
33 #include <linux/ratelimit.h>
34 #include <linux/oom.h>
35 #include <linux/notifier.h>
36 #include <linux/topology.h>
37 #include <linux/sysctl.h>
38 #include <linux/cpu.h>
39 #include <linux/cpuset.h>
40 #include <linux/memory_hotplug.h>
41 #include <linux/nodemask.h>
42 #include <linux/vmalloc.h>
43 #include <linux/vmstat.h>
44 #include <linux/mempolicy.h>
45 #include <linux/stop_machine.h>
46 #include <linux/sort.h>
47 #include <linux/pfn.h>
48 #include <linux/backing-dev.h>
49 #include <linux/fault-inject.h>
50 #include <linux/page-isolation.h>
51 #include <linux/page_cgroup.h>
52 #include <linux/debugobjects.h>
53 #include <linux/kmemleak.h>
54 #include <linux/compaction.h>
55 #include <trace/events/kmem.h>
56 #include <linux/ftrace_event.h>
57 #include <linux/memcontrol.h>
58 #include <linux/prefetch.h>
59 #include <linux/mm_inline.h>
60 #include <linux/migrate.h>
61 #include <linux/page-debug-flags.h>
62 #include <linux/hugetlb.h>
63 #include <linux/sched/rt.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_
);
91 * Array of node states.
93 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
94 [N_POSSIBLE
] = NODE_MASK_ALL
,
95 [N_ONLINE
] = { { [0] = 1UL } },
97 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
99 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
101 #ifdef CONFIG_MOVABLE_NODE
102 [N_MEMORY
] = { { [0] = 1UL } },
104 [N_CPU
] = { { [0] = 1UL } },
107 EXPORT_SYMBOL(node_states
);
109 /* Protect totalram_pages and zone->managed_pages */
110 static DEFINE_SPINLOCK(managed_page_count_lock
);
112 unsigned long totalram_pages __read_mostly
;
113 unsigned long totalreserve_pages __read_mostly
;
115 * When calculating the number of globally allowed dirty pages, there
116 * is a certain number of per-zone reserves that should not be
117 * considered dirtyable memory. This is the sum of those reserves
118 * over all existing zones that contribute dirtyable memory.
120 unsigned long dirty_balance_reserve __read_mostly
;
122 int percpu_pagelist_fraction
;
123 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
125 #ifdef CONFIG_PM_SLEEP
127 * The following functions are used by the suspend/hibernate code to temporarily
128 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
129 * while devices are suspended. To avoid races with the suspend/hibernate code,
130 * they should always be called with pm_mutex held (gfp_allowed_mask also should
131 * only be modified with pm_mutex held, unless the suspend/hibernate code is
132 * guaranteed not to run in parallel with that modification).
135 static gfp_t saved_gfp_mask
;
137 void pm_restore_gfp_mask(void)
139 WARN_ON(!mutex_is_locked(&pm_mutex
));
140 if (saved_gfp_mask
) {
141 gfp_allowed_mask
= saved_gfp_mask
;
146 void pm_restrict_gfp_mask(void)
148 WARN_ON(!mutex_is_locked(&pm_mutex
));
149 WARN_ON(saved_gfp_mask
);
150 saved_gfp_mask
= gfp_allowed_mask
;
151 gfp_allowed_mask
&= ~GFP_IOFS
;
154 bool pm_suspended_storage(void)
156 if ((gfp_allowed_mask
& GFP_IOFS
) == GFP_IOFS
)
160 #endif /* CONFIG_PM_SLEEP */
162 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
163 int pageblock_order __read_mostly
;
166 static void __free_pages_ok(struct page
*page
, unsigned int order
);
169 * results with 256, 32 in the lowmem_reserve sysctl:
170 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
171 * 1G machine -> (16M dma, 784M normal, 224M high)
172 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
173 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
174 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
176 * TBD: should special case ZONE_DMA32 machines here - in those we normally
177 * don't need any ZONE_NORMAL reservation
179 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
180 #ifdef CONFIG_ZONE_DMA
183 #ifdef CONFIG_ZONE_DMA32
186 #ifdef CONFIG_HIGHMEM
192 EXPORT_SYMBOL(totalram_pages
);
194 static char * const zone_names
[MAX_NR_ZONES
] = {
195 #ifdef CONFIG_ZONE_DMA
198 #ifdef CONFIG_ZONE_DMA32
202 #ifdef CONFIG_HIGHMEM
208 int min_free_kbytes
= 1024;
209 int user_min_free_kbytes
= -1;
211 static unsigned long __meminitdata nr_kernel_pages
;
212 static unsigned long __meminitdata nr_all_pages
;
213 static unsigned long __meminitdata dma_reserve
;
215 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
216 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
217 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
218 static unsigned long __initdata required_kernelcore
;
219 static unsigned long __initdata required_movablecore
;
220 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
222 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
224 EXPORT_SYMBOL(movable_zone
);
225 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
228 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
229 int nr_online_nodes __read_mostly
= 1;
230 EXPORT_SYMBOL(nr_node_ids
);
231 EXPORT_SYMBOL(nr_online_nodes
);
234 int page_group_by_mobility_disabled __read_mostly
;
236 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
238 if (unlikely(page_group_by_mobility_disabled
&&
239 migratetype
< MIGRATE_PCPTYPES
))
240 migratetype
= MIGRATE_UNMOVABLE
;
242 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
243 PB_migrate
, PB_migrate_end
);
246 bool oom_killer_disabled __read_mostly
;
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 /* update __split_huge_page_refcount if you change this function */
384 static int destroy_compound_page(struct page
*page
, unsigned long order
)
387 int nr_pages
= 1 << order
;
390 if (unlikely(compound_order(page
) != order
)) {
391 bad_page(page
, "wrong compound order", 0);
395 __ClearPageHead(page
);
397 for (i
= 1; i
< nr_pages
; i
++) {
398 struct page
*p
= page
+ i
;
400 if (unlikely(!PageTail(p
))) {
401 bad_page(page
, "PageTail not set", 0);
403 } else if (unlikely(p
->first_page
!= page
)) {
404 bad_page(page
, "first_page not consistent", 0);
413 static inline void prep_zero_page(struct page
*page
, unsigned int order
,
419 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
420 * and __GFP_HIGHMEM from hard or soft interrupt context.
422 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
423 for (i
= 0; i
< (1 << order
); i
++)
424 clear_highpage(page
+ i
);
427 #ifdef CONFIG_DEBUG_PAGEALLOC
428 unsigned int _debug_guardpage_minorder
;
430 static int __init
debug_guardpage_minorder_setup(char *buf
)
434 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
435 printk(KERN_ERR
"Bad debug_guardpage_minorder value\n");
438 _debug_guardpage_minorder
= res
;
439 printk(KERN_INFO
"Setting debug_guardpage_minorder to %lu\n", res
);
442 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup
);
444 static inline void set_page_guard_flag(struct page
*page
)
446 __set_bit(PAGE_DEBUG_FLAG_GUARD
, &page
->debug_flags
);
449 static inline void clear_page_guard_flag(struct page
*page
)
451 __clear_bit(PAGE_DEBUG_FLAG_GUARD
, &page
->debug_flags
);
454 static inline void set_page_guard_flag(struct page
*page
) { }
455 static inline void clear_page_guard_flag(struct page
*page
) { }
458 static inline void set_page_order(struct page
*page
, unsigned int order
)
460 set_page_private(page
, order
);
461 __SetPageBuddy(page
);
464 static inline void rmv_page_order(struct page
*page
)
466 __ClearPageBuddy(page
);
467 set_page_private(page
, 0);
471 * Locate the struct page for both the matching buddy in our
472 * pair (buddy1) and the combined O(n+1) page they form (page).
474 * 1) Any buddy B1 will have an order O twin B2 which satisfies
475 * the following equation:
477 * For example, if the starting buddy (buddy2) is #8 its order
479 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
481 * 2) Any buddy B will have an order O+1 parent P which
482 * satisfies the following equation:
485 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
487 static inline unsigned long
488 __find_buddy_index(unsigned long page_idx
, unsigned int order
)
490 return page_idx
^ (1 << order
);
494 * This function checks whether a page is free && is the buddy
495 * we can do coalesce a page and its buddy if
496 * (a) the buddy is not in a hole &&
497 * (b) the buddy is in the buddy system &&
498 * (c) a page and its buddy have the same order &&
499 * (d) a page and its buddy are in the same zone.
501 * For recording whether a page is in the buddy system, we set ->_mapcount
502 * PAGE_BUDDY_MAPCOUNT_VALUE.
503 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
504 * serialized by zone->lock.
506 * For recording page's order, we use page_private(page).
508 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
511 if (!pfn_valid_within(page_to_pfn(buddy
)))
514 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
515 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
517 if (page_zone_id(page
) != page_zone_id(buddy
))
523 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
524 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
527 * zone check is done late to avoid uselessly
528 * calculating zone/node ids for pages that could
531 if (page_zone_id(page
) != page_zone_id(buddy
))
540 * Freeing function for a buddy system allocator.
542 * The concept of a buddy system is to maintain direct-mapped table
543 * (containing bit values) for memory blocks of various "orders".
544 * The bottom level table contains the map for the smallest allocatable
545 * units of memory (here, pages), and each level above it describes
546 * pairs of units from the levels below, hence, "buddies".
547 * At a high level, all that happens here is marking the table entry
548 * at the bottom level available, and propagating the changes upward
549 * as necessary, plus some accounting needed to play nicely with other
550 * parts of the VM system.
551 * At each level, we keep a list of pages, which are heads of continuous
552 * free pages of length of (1 << order) and marked with _mapcount
553 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
555 * So when we are allocating or freeing one, we can derive the state of the
556 * other. That is, if we allocate a small block, and both were
557 * free, the remainder of the region must be split into blocks.
558 * If a block is freed, and its buddy is also free, then this
559 * triggers coalescing into a block of larger size.
564 static inline void __free_one_page(struct page
*page
,
566 struct zone
*zone
, unsigned int order
,
569 unsigned long page_idx
;
570 unsigned long combined_idx
;
571 unsigned long uninitialized_var(buddy_idx
);
574 VM_BUG_ON(!zone_is_initialized(zone
));
576 if (unlikely(PageCompound(page
)))
577 if (unlikely(destroy_compound_page(page
, order
)))
580 VM_BUG_ON(migratetype
== -1);
582 page_idx
= pfn
& ((1 << MAX_ORDER
) - 1);
584 VM_BUG_ON_PAGE(page_idx
& ((1 << order
) - 1), page
);
585 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
587 while (order
< MAX_ORDER
-1) {
588 buddy_idx
= __find_buddy_index(page_idx
, order
);
589 buddy
= page
+ (buddy_idx
- page_idx
);
590 if (!page_is_buddy(page
, buddy
, order
))
593 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
594 * merge with it and move up one order.
596 if (page_is_guard(buddy
)) {
597 clear_page_guard_flag(buddy
);
598 set_page_private(page
, 0);
599 __mod_zone_freepage_state(zone
, 1 << order
,
602 list_del(&buddy
->lru
);
603 zone
->free_area
[order
].nr_free
--;
604 rmv_page_order(buddy
);
606 combined_idx
= buddy_idx
& page_idx
;
607 page
= page
+ (combined_idx
- page_idx
);
608 page_idx
= combined_idx
;
611 set_page_order(page
, order
);
614 * If this is not the largest possible page, check if the buddy
615 * of the next-highest order is free. If it is, it's possible
616 * that pages are being freed that will coalesce soon. In case,
617 * that is happening, add the free page to the tail of the list
618 * so it's less likely to be used soon and more likely to be merged
619 * as a higher order page
621 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
622 struct page
*higher_page
, *higher_buddy
;
623 combined_idx
= buddy_idx
& page_idx
;
624 higher_page
= page
+ (combined_idx
- page_idx
);
625 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
626 higher_buddy
= higher_page
+ (buddy_idx
- combined_idx
);
627 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
628 list_add_tail(&page
->lru
,
629 &zone
->free_area
[order
].free_list
[migratetype
]);
634 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
636 zone
->free_area
[order
].nr_free
++;
639 static inline int free_pages_check(struct page
*page
)
641 const char *bad_reason
= NULL
;
642 unsigned long bad_flags
= 0;
644 if (unlikely(page_mapcount(page
)))
645 bad_reason
= "nonzero mapcount";
646 if (unlikely(page
->mapping
!= NULL
))
647 bad_reason
= "non-NULL mapping";
648 if (unlikely(atomic_read(&page
->_count
) != 0))
649 bad_reason
= "nonzero _count";
650 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)) {
651 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
652 bad_flags
= PAGE_FLAGS_CHECK_AT_FREE
;
654 if (unlikely(mem_cgroup_bad_page_check(page
)))
655 bad_reason
= "cgroup check failed";
656 if (unlikely(bad_reason
)) {
657 bad_page(page
, bad_reason
, bad_flags
);
660 page_cpupid_reset_last(page
);
661 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
662 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
667 * Frees a number of pages from the PCP lists
668 * Assumes all pages on list are in same zone, and of same order.
669 * count is the number of pages to free.
671 * If the zone was previously in an "all pages pinned" state then look to
672 * see if this freeing clears that state.
674 * And clear the zone's pages_scanned counter, to hold off the "all pages are
675 * pinned" detection logic.
677 static void free_pcppages_bulk(struct zone
*zone
, int count
,
678 struct per_cpu_pages
*pcp
)
683 unsigned long nr_scanned
;
685 spin_lock(&zone
->lock
);
686 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
688 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
692 struct list_head
*list
;
695 * Remove pages from lists in a round-robin fashion. A
696 * batch_free count is maintained that is incremented when an
697 * empty list is encountered. This is so more pages are freed
698 * off fuller lists instead of spinning excessively around empty
703 if (++migratetype
== MIGRATE_PCPTYPES
)
705 list
= &pcp
->lists
[migratetype
];
706 } while (list_empty(list
));
708 /* This is the only non-empty list. Free them all. */
709 if (batch_free
== MIGRATE_PCPTYPES
)
710 batch_free
= to_free
;
713 int mt
; /* migratetype of the to-be-freed page */
715 page
= list_entry(list
->prev
, struct page
, lru
);
716 /* must delete as __free_one_page list manipulates */
717 list_del(&page
->lru
);
718 mt
= get_freepage_migratetype(page
);
719 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
720 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
);
721 trace_mm_page_pcpu_drain(page
, 0, mt
);
722 if (likely(!is_migrate_isolate_page(page
))) {
723 __mod_zone_page_state(zone
, NR_FREE_PAGES
, 1);
724 if (is_migrate_cma(mt
))
725 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
, 1);
727 } while (--to_free
&& --batch_free
&& !list_empty(list
));
729 spin_unlock(&zone
->lock
);
732 static void free_one_page(struct zone
*zone
,
733 struct page
*page
, unsigned long pfn
,
737 unsigned long nr_scanned
;
738 spin_lock(&zone
->lock
);
739 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
741 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
743 __free_one_page(page
, pfn
, zone
, order
, migratetype
);
744 if (unlikely(!is_migrate_isolate(migratetype
)))
745 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
746 spin_unlock(&zone
->lock
);
749 static bool free_pages_prepare(struct page
*page
, unsigned int order
)
754 trace_mm_page_free(page
, order
);
755 kmemcheck_free_shadow(page
, order
);
758 page
->mapping
= NULL
;
759 for (i
= 0; i
< (1 << order
); i
++)
760 bad
+= free_pages_check(page
+ i
);
764 if (!PageHighMem(page
)) {
765 debug_check_no_locks_freed(page_address(page
),
767 debug_check_no_obj_freed(page_address(page
),
770 arch_free_page(page
, order
);
771 kernel_map_pages(page
, 1 << order
, 0);
776 static void __free_pages_ok(struct page
*page
, unsigned int order
)
780 unsigned long pfn
= page_to_pfn(page
);
782 if (!free_pages_prepare(page
, order
))
785 migratetype
= get_pfnblock_migratetype(page
, pfn
);
786 local_irq_save(flags
);
787 __count_vm_events(PGFREE
, 1 << order
);
788 set_freepage_migratetype(page
, migratetype
);
789 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
);
790 local_irq_restore(flags
);
793 void __init
__free_pages_bootmem(struct page
*page
, unsigned int order
)
795 unsigned int nr_pages
= 1 << order
;
796 struct page
*p
= page
;
800 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
802 __ClearPageReserved(p
);
803 set_page_count(p
, 0);
805 __ClearPageReserved(p
);
806 set_page_count(p
, 0);
808 page_zone(page
)->managed_pages
+= nr_pages
;
809 set_page_refcounted(page
);
810 __free_pages(page
, order
);
814 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
815 void __init
init_cma_reserved_pageblock(struct page
*page
)
817 unsigned i
= pageblock_nr_pages
;
818 struct page
*p
= page
;
821 __ClearPageReserved(p
);
822 set_page_count(p
, 0);
825 set_pageblock_migratetype(page
, MIGRATE_CMA
);
827 if (pageblock_order
>= MAX_ORDER
) {
828 i
= pageblock_nr_pages
;
831 set_page_refcounted(p
);
832 __free_pages(p
, MAX_ORDER
- 1);
833 p
+= MAX_ORDER_NR_PAGES
;
834 } while (i
-= MAX_ORDER_NR_PAGES
);
836 set_page_refcounted(page
);
837 __free_pages(page
, pageblock_order
);
840 adjust_managed_page_count(page
, pageblock_nr_pages
);
845 * The order of subdivision here is critical for the IO subsystem.
846 * Please do not alter this order without good reasons and regression
847 * testing. Specifically, as large blocks of memory are subdivided,
848 * the order in which smaller blocks are delivered depends on the order
849 * they're subdivided in this function. This is the primary factor
850 * influencing the order in which pages are delivered to the IO
851 * subsystem according to empirical testing, and this is also justified
852 * by considering the behavior of a buddy system containing a single
853 * large block of memory acted on by a series of small allocations.
854 * This behavior is a critical factor in sglist merging's success.
858 static inline void expand(struct zone
*zone
, struct page
*page
,
859 int low
, int high
, struct free_area
*area
,
862 unsigned long size
= 1 << high
;
868 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
870 #ifdef CONFIG_DEBUG_PAGEALLOC
871 if (high
< debug_guardpage_minorder()) {
873 * Mark as guard pages (or page), that will allow to
874 * merge back to allocator when buddy will be freed.
875 * Corresponding page table entries will not be touched,
876 * pages will stay not present in virtual address space
878 INIT_LIST_HEAD(&page
[size
].lru
);
879 set_page_guard_flag(&page
[size
]);
880 set_page_private(&page
[size
], high
);
881 /* Guard pages are not available for any usage */
882 __mod_zone_freepage_state(zone
, -(1 << high
),
887 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
889 set_page_order(&page
[size
], high
);
894 * This page is about to be returned from the page allocator
896 static inline int check_new_page(struct page
*page
)
898 const char *bad_reason
= NULL
;
899 unsigned long bad_flags
= 0;
901 if (unlikely(page_mapcount(page
)))
902 bad_reason
= "nonzero mapcount";
903 if (unlikely(page
->mapping
!= NULL
))
904 bad_reason
= "non-NULL mapping";
905 if (unlikely(atomic_read(&page
->_count
) != 0))
906 bad_reason
= "nonzero _count";
907 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)) {
908 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag set";
909 bad_flags
= PAGE_FLAGS_CHECK_AT_PREP
;
911 if (unlikely(mem_cgroup_bad_page_check(page
)))
912 bad_reason
= "cgroup check failed";
913 if (unlikely(bad_reason
)) {
914 bad_page(page
, bad_reason
, bad_flags
);
920 static int prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
)
924 for (i
= 0; i
< (1 << order
); i
++) {
925 struct page
*p
= page
+ i
;
926 if (unlikely(check_new_page(p
)))
930 set_page_private(page
, 0);
931 set_page_refcounted(page
);
933 arch_alloc_page(page
, order
);
934 kernel_map_pages(page
, 1 << order
, 1);
936 if (gfp_flags
& __GFP_ZERO
)
937 prep_zero_page(page
, order
, gfp_flags
);
939 if (order
&& (gfp_flags
& __GFP_COMP
))
940 prep_compound_page(page
, order
);
946 * Go through the free lists for the given migratetype and remove
947 * the smallest available page from the freelists
950 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
953 unsigned int current_order
;
954 struct free_area
*area
;
957 /* Find a page of the appropriate size in the preferred list */
958 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
959 area
= &(zone
->free_area
[current_order
]);
960 if (list_empty(&area
->free_list
[migratetype
]))
963 page
= list_entry(area
->free_list
[migratetype
].next
,
965 list_del(&page
->lru
);
966 rmv_page_order(page
);
968 expand(zone
, page
, order
, current_order
, area
, migratetype
);
969 set_freepage_migratetype(page
, migratetype
);
978 * This array describes the order lists are fallen back to when
979 * the free lists for the desirable migrate type are depleted
981 static int fallbacks
[MIGRATE_TYPES
][4] = {
982 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
983 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
985 [MIGRATE_MOVABLE
] = { MIGRATE_CMA
, MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
986 [MIGRATE_CMA
] = { MIGRATE_RESERVE
}, /* Never used */
988 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
990 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
}, /* Never used */
991 #ifdef CONFIG_MEMORY_ISOLATION
992 [MIGRATE_ISOLATE
] = { MIGRATE_RESERVE
}, /* Never used */
997 * Move the free pages in a range to the free lists of the requested type.
998 * Note that start_page and end_pages are not aligned on a pageblock
999 * boundary. If alignment is required, use move_freepages_block()
1001 int move_freepages(struct zone
*zone
,
1002 struct page
*start_page
, struct page
*end_page
,
1006 unsigned long order
;
1007 int pages_moved
= 0;
1009 #ifndef CONFIG_HOLES_IN_ZONE
1011 * page_zone is not safe to call in this context when
1012 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1013 * anyway as we check zone boundaries in move_freepages_block().
1014 * Remove at a later date when no bug reports exist related to
1015 * grouping pages by mobility
1017 BUG_ON(page_zone(start_page
) != page_zone(end_page
));
1020 for (page
= start_page
; page
<= end_page
;) {
1021 /* Make sure we are not inadvertently changing nodes */
1022 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
1024 if (!pfn_valid_within(page_to_pfn(page
))) {
1029 if (!PageBuddy(page
)) {
1034 order
= page_order(page
);
1035 list_move(&page
->lru
,
1036 &zone
->free_area
[order
].free_list
[migratetype
]);
1037 set_freepage_migratetype(page
, migratetype
);
1039 pages_moved
+= 1 << order
;
1045 int move_freepages_block(struct zone
*zone
, struct page
*page
,
1048 unsigned long start_pfn
, end_pfn
;
1049 struct page
*start_page
, *end_page
;
1051 start_pfn
= page_to_pfn(page
);
1052 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
1053 start_page
= pfn_to_page(start_pfn
);
1054 end_page
= start_page
+ pageblock_nr_pages
- 1;
1055 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
1057 /* Do not cross zone boundaries */
1058 if (!zone_spans_pfn(zone
, start_pfn
))
1060 if (!zone_spans_pfn(zone
, end_pfn
))
1063 return move_freepages(zone
, start_page
, end_page
, migratetype
);
1066 static void change_pageblock_range(struct page
*pageblock_page
,
1067 int start_order
, int migratetype
)
1069 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
1071 while (nr_pageblocks
--) {
1072 set_pageblock_migratetype(pageblock_page
, migratetype
);
1073 pageblock_page
+= pageblock_nr_pages
;
1078 * If breaking a large block of pages, move all free pages to the preferred
1079 * allocation list. If falling back for a reclaimable kernel allocation, be
1080 * more aggressive about taking ownership of free pages.
1082 * On the other hand, never change migration type of MIGRATE_CMA pageblocks
1083 * nor move CMA pages to different free lists. We don't want unmovable pages
1084 * to be allocated from MIGRATE_CMA areas.
1086 * Returns the new migratetype of the pageblock (or the same old migratetype
1087 * if it was unchanged).
1089 static int try_to_steal_freepages(struct zone
*zone
, struct page
*page
,
1090 int start_type
, int fallback_type
)
1092 int current_order
= page_order(page
);
1095 * When borrowing from MIGRATE_CMA, we need to release the excess
1096 * buddy pages to CMA itself. We also ensure the freepage_migratetype
1097 * is set to CMA so it is returned to the correct freelist in case
1098 * the page ends up being not actually allocated from the pcp lists.
1100 if (is_migrate_cma(fallback_type
))
1101 return fallback_type
;
1103 /* Take ownership for orders >= pageblock_order */
1104 if (current_order
>= pageblock_order
) {
1105 change_pageblock_range(page
, current_order
, start_type
);
1109 if (current_order
>= pageblock_order
/ 2 ||
1110 start_type
== MIGRATE_RECLAIMABLE
||
1111 page_group_by_mobility_disabled
) {
1114 pages
= move_freepages_block(zone
, page
, start_type
);
1116 /* Claim the whole block if over half of it is free */
1117 if (pages
>= (1 << (pageblock_order
-1)) ||
1118 page_group_by_mobility_disabled
) {
1120 set_pageblock_migratetype(page
, start_type
);
1126 return fallback_type
;
1129 /* Remove an element from the buddy allocator from the fallback list */
1130 static inline struct page
*
1131 __rmqueue_fallback(struct zone
*zone
, unsigned int order
, int start_migratetype
)
1133 struct free_area
*area
;
1134 unsigned int current_order
;
1136 int migratetype
, new_type
, i
;
1138 /* Find the largest possible block of pages in the other list */
1139 for (current_order
= MAX_ORDER
-1;
1140 current_order
>= order
&& current_order
<= MAX_ORDER
-1;
1143 migratetype
= fallbacks
[start_migratetype
][i
];
1145 /* MIGRATE_RESERVE handled later if necessary */
1146 if (migratetype
== MIGRATE_RESERVE
)
1149 area
= &(zone
->free_area
[current_order
]);
1150 if (list_empty(&area
->free_list
[migratetype
]))
1153 page
= list_entry(area
->free_list
[migratetype
].next
,
1157 new_type
= try_to_steal_freepages(zone
, page
,
1161 /* Remove the page from the freelists */
1162 list_del(&page
->lru
);
1163 rmv_page_order(page
);
1165 expand(zone
, page
, order
, current_order
, area
,
1167 /* The freepage_migratetype may differ from pageblock's
1168 * migratetype depending on the decisions in
1169 * try_to_steal_freepages. This is OK as long as it does
1170 * not differ for MIGRATE_CMA type.
1172 set_freepage_migratetype(page
, new_type
);
1174 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
1175 start_migratetype
, migratetype
, new_type
);
1185 * Do the hard work of removing an element from the buddy allocator.
1186 * Call me with the zone->lock already held.
1188 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
1194 page
= __rmqueue_smallest(zone
, order
, migratetype
);
1196 if (unlikely(!page
) && migratetype
!= MIGRATE_RESERVE
) {
1197 page
= __rmqueue_fallback(zone
, order
, migratetype
);
1200 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1201 * is used because __rmqueue_smallest is an inline function
1202 * and we want just one call site
1205 migratetype
= MIGRATE_RESERVE
;
1210 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
1215 * Obtain a specified number of elements from the buddy allocator, all under
1216 * a single hold of the lock, for efficiency. Add them to the supplied list.
1217 * Returns the number of new pages which were placed at *list.
1219 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
1220 unsigned long count
, struct list_head
*list
,
1221 int migratetype
, bool cold
)
1225 spin_lock(&zone
->lock
);
1226 for (i
= 0; i
< count
; ++i
) {
1227 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
1228 if (unlikely(page
== NULL
))
1232 * Split buddy pages returned by expand() are received here
1233 * in physical page order. The page is added to the callers and
1234 * list and the list head then moves forward. From the callers
1235 * perspective, the linked list is ordered by page number in
1236 * some conditions. This is useful for IO devices that can
1237 * merge IO requests if the physical pages are ordered
1241 list_add(&page
->lru
, list
);
1243 list_add_tail(&page
->lru
, list
);
1245 if (is_migrate_cma(get_freepage_migratetype(page
)))
1246 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
1249 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
1250 spin_unlock(&zone
->lock
);
1256 * Called from the vmstat counter updater to drain pagesets of this
1257 * currently executing processor on remote nodes after they have
1260 * Note that this function must be called with the thread pinned to
1261 * a single processor.
1263 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
1265 unsigned long flags
;
1266 int to_drain
, batch
;
1268 local_irq_save(flags
);
1269 batch
= ACCESS_ONCE(pcp
->batch
);
1270 to_drain
= min(pcp
->count
, batch
);
1272 free_pcppages_bulk(zone
, to_drain
, pcp
);
1273 pcp
->count
-= to_drain
;
1275 local_irq_restore(flags
);
1280 * Drain pages of the indicated processor.
1282 * The processor must either be the current processor and the
1283 * thread pinned to the current processor or a processor that
1286 static void drain_pages(unsigned int cpu
)
1288 unsigned long flags
;
1291 for_each_populated_zone(zone
) {
1292 struct per_cpu_pageset
*pset
;
1293 struct per_cpu_pages
*pcp
;
1295 local_irq_save(flags
);
1296 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
1300 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
1303 local_irq_restore(flags
);
1308 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1310 void drain_local_pages(void *arg
)
1312 drain_pages(smp_processor_id());
1316 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
1318 * Note that this code is protected against sending an IPI to an offline
1319 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
1320 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
1321 * nothing keeps CPUs from showing up after we populated the cpumask and
1322 * before the call to on_each_cpu_mask().
1324 void drain_all_pages(void)
1327 struct per_cpu_pageset
*pcp
;
1331 * Allocate in the BSS so we wont require allocation in
1332 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
1334 static cpumask_t cpus_with_pcps
;
1337 * We don't care about racing with CPU hotplug event
1338 * as offline notification will cause the notified
1339 * cpu to drain that CPU pcps and on_each_cpu_mask
1340 * disables preemption as part of its processing
1342 for_each_online_cpu(cpu
) {
1343 bool has_pcps
= false;
1344 for_each_populated_zone(zone
) {
1345 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
1346 if (pcp
->pcp
.count
) {
1352 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
1354 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
1356 on_each_cpu_mask(&cpus_with_pcps
, drain_local_pages
, NULL
, 1);
1359 #ifdef CONFIG_HIBERNATION
1361 void mark_free_pages(struct zone
*zone
)
1363 unsigned long pfn
, max_zone_pfn
;
1364 unsigned long flags
;
1365 unsigned int order
, t
;
1366 struct list_head
*curr
;
1368 if (zone_is_empty(zone
))
1371 spin_lock_irqsave(&zone
->lock
, flags
);
1373 max_zone_pfn
= zone_end_pfn(zone
);
1374 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1375 if (pfn_valid(pfn
)) {
1376 struct page
*page
= pfn_to_page(pfn
);
1378 if (!swsusp_page_is_forbidden(page
))
1379 swsusp_unset_page_free(page
);
1382 for_each_migratetype_order(order
, t
) {
1383 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
1386 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
1387 for (i
= 0; i
< (1UL << order
); i
++)
1388 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
1391 spin_unlock_irqrestore(&zone
->lock
, flags
);
1393 #endif /* CONFIG_PM */
1396 * Free a 0-order page
1397 * cold == true ? free a cold page : free a hot page
1399 void free_hot_cold_page(struct page
*page
, bool cold
)
1401 struct zone
*zone
= page_zone(page
);
1402 struct per_cpu_pages
*pcp
;
1403 unsigned long flags
;
1404 unsigned long pfn
= page_to_pfn(page
);
1407 if (!free_pages_prepare(page
, 0))
1410 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1411 set_freepage_migratetype(page
, migratetype
);
1412 local_irq_save(flags
);
1413 __count_vm_event(PGFREE
);
1416 * We only track unmovable, reclaimable and movable on pcp lists.
1417 * Free ISOLATE pages back to the allocator because they are being
1418 * offlined but treat RESERVE as movable pages so we can get those
1419 * areas back if necessary. Otherwise, we may have to free
1420 * excessively into the page allocator
1422 if (migratetype
>= MIGRATE_PCPTYPES
) {
1423 if (unlikely(is_migrate_isolate(migratetype
))) {
1424 free_one_page(zone
, page
, pfn
, 0, migratetype
);
1427 migratetype
= MIGRATE_MOVABLE
;
1430 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1432 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
1434 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
1436 if (pcp
->count
>= pcp
->high
) {
1437 unsigned long batch
= ACCESS_ONCE(pcp
->batch
);
1438 free_pcppages_bulk(zone
, batch
, pcp
);
1439 pcp
->count
-= batch
;
1443 local_irq_restore(flags
);
1447 * Free a list of 0-order pages
1449 void free_hot_cold_page_list(struct list_head
*list
, bool cold
)
1451 struct page
*page
, *next
;
1453 list_for_each_entry_safe(page
, next
, list
, lru
) {
1454 trace_mm_page_free_batched(page
, cold
);
1455 free_hot_cold_page(page
, cold
);
1460 * split_page takes a non-compound higher-order page, and splits it into
1461 * n (1<<order) sub-pages: page[0..n]
1462 * Each sub-page must be freed individually.
1464 * Note: this is probably too low level an operation for use in drivers.
1465 * Please consult with lkml before using this in your driver.
1467 void split_page(struct page
*page
, unsigned int order
)
1471 VM_BUG_ON_PAGE(PageCompound(page
), page
);
1472 VM_BUG_ON_PAGE(!page_count(page
), page
);
1474 #ifdef CONFIG_KMEMCHECK
1476 * Split shadow pages too, because free(page[0]) would
1477 * otherwise free the whole shadow.
1479 if (kmemcheck_page_is_tracked(page
))
1480 split_page(virt_to_page(page
[0].shadow
), order
);
1483 for (i
= 1; i
< (1 << order
); i
++)
1484 set_page_refcounted(page
+ i
);
1486 EXPORT_SYMBOL_GPL(split_page
);
1488 static int __isolate_free_page(struct page
*page
, unsigned int order
)
1490 unsigned long watermark
;
1494 BUG_ON(!PageBuddy(page
));
1496 zone
= page_zone(page
);
1497 mt
= get_pageblock_migratetype(page
);
1499 if (!is_migrate_isolate(mt
)) {
1500 /* Obey watermarks as if the page was being allocated */
1501 watermark
= low_wmark_pages(zone
) + (1 << order
);
1502 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
1505 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
1508 /* Remove page from free list */
1509 list_del(&page
->lru
);
1510 zone
->free_area
[order
].nr_free
--;
1511 rmv_page_order(page
);
1513 /* Set the pageblock if the isolated page is at least a pageblock */
1514 if (order
>= pageblock_order
- 1) {
1515 struct page
*endpage
= page
+ (1 << order
) - 1;
1516 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
1517 int mt
= get_pageblock_migratetype(page
);
1518 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
))
1519 set_pageblock_migratetype(page
,
1524 return 1UL << order
;
1528 * Similar to split_page except the page is already free. As this is only
1529 * being used for migration, the migratetype of the block also changes.
1530 * As this is called with interrupts disabled, the caller is responsible
1531 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1534 * Note: this is probably too low level an operation for use in drivers.
1535 * Please consult with lkml before using this in your driver.
1537 int split_free_page(struct page
*page
)
1542 order
= page_order(page
);
1544 nr_pages
= __isolate_free_page(page
, order
);
1548 /* Split into individual pages */
1549 set_page_refcounted(page
);
1550 split_page(page
, order
);
1555 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1556 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1560 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
1561 struct zone
*zone
, unsigned int order
,
1562 gfp_t gfp_flags
, int migratetype
)
1564 unsigned long flags
;
1566 bool cold
= ((gfp_flags
& __GFP_COLD
) != 0);
1569 if (likely(order
== 0)) {
1570 struct per_cpu_pages
*pcp
;
1571 struct list_head
*list
;
1573 local_irq_save(flags
);
1574 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1575 list
= &pcp
->lists
[migratetype
];
1576 if (list_empty(list
)) {
1577 pcp
->count
+= rmqueue_bulk(zone
, 0,
1580 if (unlikely(list_empty(list
)))
1585 page
= list_entry(list
->prev
, struct page
, lru
);
1587 page
= list_entry(list
->next
, struct page
, lru
);
1589 list_del(&page
->lru
);
1592 if (unlikely(gfp_flags
& __GFP_NOFAIL
)) {
1594 * __GFP_NOFAIL is not to be used in new code.
1596 * All __GFP_NOFAIL callers should be fixed so that they
1597 * properly detect and handle allocation failures.
1599 * We most definitely don't want callers attempting to
1600 * allocate greater than order-1 page units with
1603 WARN_ON_ONCE(order
> 1);
1605 spin_lock_irqsave(&zone
->lock
, flags
);
1606 page
= __rmqueue(zone
, order
, migratetype
);
1607 spin_unlock(&zone
->lock
);
1610 __mod_zone_freepage_state(zone
, -(1 << order
),
1611 get_freepage_migratetype(page
));
1614 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
, -(1 << order
));
1615 if (atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]) <= 0 &&
1616 !zone_is_fair_depleted(zone
))
1617 zone_set_flag(zone
, ZONE_FAIR_DEPLETED
);
1619 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
1620 zone_statistics(preferred_zone
, zone
, gfp_flags
);
1621 local_irq_restore(flags
);
1623 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
1624 if (prep_new_page(page
, order
, gfp_flags
))
1629 local_irq_restore(flags
);
1633 #ifdef CONFIG_FAIL_PAGE_ALLOC
1636 struct fault_attr attr
;
1638 u32 ignore_gfp_highmem
;
1639 u32 ignore_gfp_wait
;
1641 } fail_page_alloc
= {
1642 .attr
= FAULT_ATTR_INITIALIZER
,
1643 .ignore_gfp_wait
= 1,
1644 .ignore_gfp_highmem
= 1,
1648 static int __init
setup_fail_page_alloc(char *str
)
1650 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
1652 __setup("fail_page_alloc=", setup_fail_page_alloc
);
1654 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1656 if (order
< fail_page_alloc
.min_order
)
1658 if (gfp_mask
& __GFP_NOFAIL
)
1660 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
1662 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
1665 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
1668 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1670 static int __init
fail_page_alloc_debugfs(void)
1672 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
1675 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
1676 &fail_page_alloc
.attr
);
1678 return PTR_ERR(dir
);
1680 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
1681 &fail_page_alloc
.ignore_gfp_wait
))
1683 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
1684 &fail_page_alloc
.ignore_gfp_highmem
))
1686 if (!debugfs_create_u32("min-order", mode
, dir
,
1687 &fail_page_alloc
.min_order
))
1692 debugfs_remove_recursive(dir
);
1697 late_initcall(fail_page_alloc_debugfs
);
1699 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1701 #else /* CONFIG_FAIL_PAGE_ALLOC */
1703 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1708 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1711 * Return true if free pages are above 'mark'. This takes into account the order
1712 * of the allocation.
1714 static bool __zone_watermark_ok(struct zone
*z
, unsigned int order
,
1715 unsigned long mark
, int classzone_idx
, int alloc_flags
,
1718 /* free_pages my go negative - that's OK */
1723 free_pages
-= (1 << order
) - 1;
1724 if (alloc_flags
& ALLOC_HIGH
)
1726 if (alloc_flags
& ALLOC_HARDER
)
1729 /* If allocation can't use CMA areas don't use free CMA pages */
1730 if (!(alloc_flags
& ALLOC_CMA
))
1731 free_cma
= zone_page_state(z
, NR_FREE_CMA_PAGES
);
1734 if (free_pages
- free_cma
<= min
+ z
->lowmem_reserve
[classzone_idx
])
1736 for (o
= 0; o
< order
; o
++) {
1737 /* At the next order, this order's pages become unavailable */
1738 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
1740 /* Require fewer higher order pages to be free */
1743 if (free_pages
<= min
)
1749 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
1750 int classzone_idx
, int alloc_flags
)
1752 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1753 zone_page_state(z
, NR_FREE_PAGES
));
1756 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
1757 unsigned long mark
, int classzone_idx
, int alloc_flags
)
1759 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
1761 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
1762 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
1764 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1770 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1771 * skip over zones that are not allowed by the cpuset, or that have
1772 * been recently (in last second) found to be nearly full. See further
1773 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1774 * that have to skip over a lot of full or unallowed zones.
1776 * If the zonelist cache is present in the passed zonelist, then
1777 * returns a pointer to the allowed node mask (either the current
1778 * tasks mems_allowed, or node_states[N_MEMORY].)
1780 * If the zonelist cache is not available for this zonelist, does
1781 * nothing and returns NULL.
1783 * If the fullzones BITMAP in the zonelist cache is stale (more than
1784 * a second since last zap'd) then we zap it out (clear its bits.)
1786 * We hold off even calling zlc_setup, until after we've checked the
1787 * first zone in the zonelist, on the theory that most allocations will
1788 * be satisfied from that first zone, so best to examine that zone as
1789 * quickly as we can.
1791 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1793 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1794 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
1796 zlc
= zonelist
->zlcache_ptr
;
1800 if (time_after(jiffies
, zlc
->last_full_zap
+ HZ
)) {
1801 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1802 zlc
->last_full_zap
= jiffies
;
1805 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
1806 &cpuset_current_mems_allowed
:
1807 &node_states
[N_MEMORY
];
1808 return allowednodes
;
1812 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1813 * if it is worth looking at further for free memory:
1814 * 1) Check that the zone isn't thought to be full (doesn't have its
1815 * bit set in the zonelist_cache fullzones BITMAP).
1816 * 2) Check that the zones node (obtained from the zonelist_cache
1817 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1818 * Return true (non-zero) if zone is worth looking at further, or
1819 * else return false (zero) if it is not.
1821 * This check -ignores- the distinction between various watermarks,
1822 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1823 * found to be full for any variation of these watermarks, it will
1824 * be considered full for up to one second by all requests, unless
1825 * we are so low on memory on all allowed nodes that we are forced
1826 * into the second scan of the zonelist.
1828 * In the second scan we ignore this zonelist cache and exactly
1829 * apply the watermarks to all zones, even it is slower to do so.
1830 * We are low on memory in the second scan, and should leave no stone
1831 * unturned looking for a free page.
1833 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1834 nodemask_t
*allowednodes
)
1836 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1837 int i
; /* index of *z in zonelist zones */
1838 int n
; /* node that zone *z is on */
1840 zlc
= zonelist
->zlcache_ptr
;
1844 i
= z
- zonelist
->_zonerefs
;
1847 /* This zone is worth trying if it is allowed but not full */
1848 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1852 * Given 'z' scanning a zonelist, set the corresponding bit in
1853 * zlc->fullzones, so that subsequent attempts to allocate a page
1854 * from that zone don't waste time re-examining it.
1856 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1858 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1859 int i
; /* index of *z in zonelist zones */
1861 zlc
= zonelist
->zlcache_ptr
;
1865 i
= z
- zonelist
->_zonerefs
;
1867 set_bit(i
, zlc
->fullzones
);
1871 * clear all zones full, called after direct reclaim makes progress so that
1872 * a zone that was recently full is not skipped over for up to a second
1874 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
1876 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1878 zlc
= zonelist
->zlcache_ptr
;
1882 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1885 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
1887 return local_zone
->node
== zone
->node
;
1890 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
1892 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <
1896 #else /* CONFIG_NUMA */
1898 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1903 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1904 nodemask_t
*allowednodes
)
1909 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1913 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
1917 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
1922 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
1927 #endif /* CONFIG_NUMA */
1929 static void reset_alloc_batches(struct zone
*preferred_zone
)
1931 struct zone
*zone
= preferred_zone
->zone_pgdat
->node_zones
;
1934 mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
1935 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
1936 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
1937 zone_clear_flag(zone
, ZONE_FAIR_DEPLETED
);
1938 } while (zone
++ != preferred_zone
);
1942 * get_page_from_freelist goes through the zonelist trying to allocate
1945 static struct page
*
1946 get_page_from_freelist(gfp_t gfp_mask
, nodemask_t
*nodemask
, unsigned int order
,
1947 struct zonelist
*zonelist
, int high_zoneidx
, int alloc_flags
,
1948 struct zone
*preferred_zone
, int classzone_idx
, int migratetype
)
1951 struct page
*page
= NULL
;
1953 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
1954 int zlc_active
= 0; /* set if using zonelist_cache */
1955 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
1956 bool consider_zone_dirty
= (alloc_flags
& ALLOC_WMARK_LOW
) &&
1957 (gfp_mask
& __GFP_WRITE
);
1958 int nr_fair_skipped
= 0;
1959 bool zonelist_rescan
;
1962 zonelist_rescan
= false;
1965 * Scan zonelist, looking for a zone with enough free.
1966 * See also __cpuset_node_allowed_softwall() comment in kernel/cpuset.c.
1968 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
1969 high_zoneidx
, nodemask
) {
1972 if (IS_ENABLED(CONFIG_NUMA
) && zlc_active
&&
1973 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1975 if (cpusets_enabled() &&
1976 (alloc_flags
& ALLOC_CPUSET
) &&
1977 !cpuset_zone_allowed_softwall(zone
, gfp_mask
))
1980 * Distribute pages in proportion to the individual
1981 * zone size to ensure fair page aging. The zone a
1982 * page was allocated in should have no effect on the
1983 * time the page has in memory before being reclaimed.
1985 if (alloc_flags
& ALLOC_FAIR
) {
1986 if (!zone_local(preferred_zone
, zone
))
1988 if (zone_is_fair_depleted(zone
)) {
1994 * When allocating a page cache page for writing, we
1995 * want to get it from a zone that is within its dirty
1996 * limit, such that no single zone holds more than its
1997 * proportional share of globally allowed dirty pages.
1998 * The dirty limits take into account the zone's
1999 * lowmem reserves and high watermark so that kswapd
2000 * should be able to balance it without having to
2001 * write pages from its LRU list.
2003 * This may look like it could increase pressure on
2004 * lower zones by failing allocations in higher zones
2005 * before they are full. But the pages that do spill
2006 * over are limited as the lower zones are protected
2007 * by this very same mechanism. It should not become
2008 * a practical burden to them.
2010 * XXX: For now, allow allocations to potentially
2011 * exceed the per-zone dirty limit in the slowpath
2012 * (ALLOC_WMARK_LOW unset) before going into reclaim,
2013 * which is important when on a NUMA setup the allowed
2014 * zones are together not big enough to reach the
2015 * global limit. The proper fix for these situations
2016 * will require awareness of zones in the
2017 * dirty-throttling and the flusher threads.
2019 if (consider_zone_dirty
&& !zone_dirty_ok(zone
))
2022 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
2023 if (!zone_watermark_ok(zone
, order
, mark
,
2024 classzone_idx
, alloc_flags
)) {
2027 /* Checked here to keep the fast path fast */
2028 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
2029 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
2032 if (IS_ENABLED(CONFIG_NUMA
) &&
2033 !did_zlc_setup
&& nr_online_nodes
> 1) {
2035 * we do zlc_setup if there are multiple nodes
2036 * and before considering the first zone allowed
2039 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
2044 if (zone_reclaim_mode
== 0 ||
2045 !zone_allows_reclaim(preferred_zone
, zone
))
2046 goto this_zone_full
;
2049 * As we may have just activated ZLC, check if the first
2050 * eligible zone has failed zone_reclaim recently.
2052 if (IS_ENABLED(CONFIG_NUMA
) && zlc_active
&&
2053 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
2056 ret
= zone_reclaim(zone
, gfp_mask
, order
);
2058 case ZONE_RECLAIM_NOSCAN
:
2061 case ZONE_RECLAIM_FULL
:
2062 /* scanned but unreclaimable */
2065 /* did we reclaim enough */
2066 if (zone_watermark_ok(zone
, order
, mark
,
2067 classzone_idx
, alloc_flags
))
2071 * Failed to reclaim enough to meet watermark.
2072 * Only mark the zone full if checking the min
2073 * watermark or if we failed to reclaim just
2074 * 1<<order pages or else the page allocator
2075 * fastpath will prematurely mark zones full
2076 * when the watermark is between the low and
2079 if (((alloc_flags
& ALLOC_WMARK_MASK
) == ALLOC_WMARK_MIN
) ||
2080 ret
== ZONE_RECLAIM_SOME
)
2081 goto this_zone_full
;
2088 page
= buffered_rmqueue(preferred_zone
, zone
, order
,
2089 gfp_mask
, migratetype
);
2093 if (IS_ENABLED(CONFIG_NUMA
) && zlc_active
)
2094 zlc_mark_zone_full(zonelist
, z
);
2099 * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was
2100 * necessary to allocate the page. The expectation is
2101 * that the caller is taking steps that will free more
2102 * memory. The caller should avoid the page being used
2103 * for !PFMEMALLOC purposes.
2105 page
->pfmemalloc
= !!(alloc_flags
& ALLOC_NO_WATERMARKS
);
2110 * The first pass makes sure allocations are spread fairly within the
2111 * local node. However, the local node might have free pages left
2112 * after the fairness batches are exhausted, and remote zones haven't
2113 * even been considered yet. Try once more without fairness, and
2114 * include remote zones now, before entering the slowpath and waking
2115 * kswapd: prefer spilling to a remote zone over swapping locally.
2117 if (alloc_flags
& ALLOC_FAIR
) {
2118 alloc_flags
&= ~ALLOC_FAIR
;
2119 if (nr_fair_skipped
) {
2120 zonelist_rescan
= true;
2121 reset_alloc_batches(preferred_zone
);
2123 if (nr_online_nodes
> 1)
2124 zonelist_rescan
= true;
2127 if (unlikely(IS_ENABLED(CONFIG_NUMA
) && zlc_active
)) {
2128 /* Disable zlc cache for second zonelist scan */
2130 zonelist_rescan
= true;
2133 if (zonelist_rescan
)
2140 * Large machines with many possible nodes should not always dump per-node
2141 * meminfo in irq context.
2143 static inline bool should_suppress_show_mem(void)
2148 ret
= in_interrupt();
2153 static DEFINE_RATELIMIT_STATE(nopage_rs
,
2154 DEFAULT_RATELIMIT_INTERVAL
,
2155 DEFAULT_RATELIMIT_BURST
);
2157 void warn_alloc_failed(gfp_t gfp_mask
, int order
, const char *fmt
, ...)
2159 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
2161 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
2162 debug_guardpage_minorder() > 0)
2166 * This documents exceptions given to allocations in certain
2167 * contexts that are allowed to allocate outside current's set
2170 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2171 if (test_thread_flag(TIF_MEMDIE
) ||
2172 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
2173 filter
&= ~SHOW_MEM_FILTER_NODES
;
2174 if (in_interrupt() || !(gfp_mask
& __GFP_WAIT
))
2175 filter
&= ~SHOW_MEM_FILTER_NODES
;
2178 struct va_format vaf
;
2181 va_start(args
, fmt
);
2186 pr_warn("%pV", &vaf
);
2191 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
2192 current
->comm
, order
, gfp_mask
);
2195 if (!should_suppress_show_mem())
2200 should_alloc_retry(gfp_t gfp_mask
, unsigned int order
,
2201 unsigned long did_some_progress
,
2202 unsigned long pages_reclaimed
)
2204 /* Do not loop if specifically requested */
2205 if (gfp_mask
& __GFP_NORETRY
)
2208 /* Always retry if specifically requested */
2209 if (gfp_mask
& __GFP_NOFAIL
)
2213 * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
2214 * making forward progress without invoking OOM. Suspend also disables
2215 * storage devices so kswapd will not help. Bail if we are suspending.
2217 if (!did_some_progress
&& pm_suspended_storage())
2221 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
2222 * means __GFP_NOFAIL, but that may not be true in other
2225 if (order
<= PAGE_ALLOC_COSTLY_ORDER
)
2229 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
2230 * specified, then we retry until we no longer reclaim any pages
2231 * (above), or we've reclaimed an order of pages at least as
2232 * large as the allocation's order. In both cases, if the
2233 * allocation still fails, we stop retrying.
2235 if (gfp_mask
& __GFP_REPEAT
&& pages_reclaimed
< (1 << order
))
2241 static inline struct page
*
2242 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
2243 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2244 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2245 int classzone_idx
, int migratetype
)
2249 /* Acquire the per-zone oom lock for each zone */
2250 if (!oom_zonelist_trylock(zonelist
, gfp_mask
)) {
2251 schedule_timeout_uninterruptible(1);
2256 * Go through the zonelist yet one more time, keep very high watermark
2257 * here, this is only to catch a parallel oom killing, we must fail if
2258 * we're still under heavy pressure.
2260 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
,
2261 order
, zonelist
, high_zoneidx
,
2262 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
,
2263 preferred_zone
, classzone_idx
, migratetype
);
2267 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2268 /* The OOM killer will not help higher order allocs */
2269 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2271 /* The OOM killer does not needlessly kill tasks for lowmem */
2272 if (high_zoneidx
< ZONE_NORMAL
)
2275 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
2276 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
2277 * The caller should handle page allocation failure by itself if
2278 * it specifies __GFP_THISNODE.
2279 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
2281 if (gfp_mask
& __GFP_THISNODE
)
2284 /* Exhausted what can be done so it's blamo time */
2285 out_of_memory(zonelist
, gfp_mask
, order
, nodemask
, false);
2288 oom_zonelist_unlock(zonelist
, gfp_mask
);
2292 #ifdef CONFIG_COMPACTION
2293 /* Try memory compaction for high-order allocations before reclaim */
2294 static struct page
*
2295 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2296 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2297 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2298 int classzone_idx
, int migratetype
, enum migrate_mode mode
,
2299 bool *contended_compaction
, bool *deferred_compaction
,
2300 unsigned long *did_some_progress
)
2305 if (compaction_deferred(preferred_zone
, order
)) {
2306 *deferred_compaction
= true;
2310 current
->flags
|= PF_MEMALLOC
;
2311 *did_some_progress
= try_to_compact_pages(zonelist
, order
, gfp_mask
,
2313 contended_compaction
);
2314 current
->flags
&= ~PF_MEMALLOC
;
2316 if (*did_some_progress
!= COMPACT_SKIPPED
) {
2319 /* Page migration frees to the PCP lists but we want merging */
2320 drain_pages(get_cpu());
2323 page
= get_page_from_freelist(gfp_mask
, nodemask
,
2324 order
, zonelist
, high_zoneidx
,
2325 alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2326 preferred_zone
, classzone_idx
, migratetype
);
2328 preferred_zone
->compact_blockskip_flush
= false;
2329 compaction_defer_reset(preferred_zone
, order
, true);
2330 count_vm_event(COMPACTSUCCESS
);
2335 * It's bad if compaction run occurs and fails.
2336 * The most likely reason is that pages exist,
2337 * but not enough to satisfy watermarks.
2339 count_vm_event(COMPACTFAIL
);
2342 * As async compaction considers a subset of pageblocks, only
2343 * defer if the failure was a sync compaction failure.
2345 if (mode
!= MIGRATE_ASYNC
)
2346 defer_compaction(preferred_zone
, order
);
2354 static inline struct page
*
2355 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2356 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2357 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2358 int classzone_idx
, int migratetype
,
2359 enum migrate_mode mode
, bool *contended_compaction
,
2360 bool *deferred_compaction
, unsigned long *did_some_progress
)
2364 #endif /* CONFIG_COMPACTION */
2366 /* Perform direct synchronous page reclaim */
2368 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
, struct zonelist
*zonelist
,
2369 nodemask_t
*nodemask
)
2371 struct reclaim_state reclaim_state
;
2376 /* We now go into synchronous reclaim */
2377 cpuset_memory_pressure_bump();
2378 current
->flags
|= PF_MEMALLOC
;
2379 lockdep_set_current_reclaim_state(gfp_mask
);
2380 reclaim_state
.reclaimed_slab
= 0;
2381 current
->reclaim_state
= &reclaim_state
;
2383 progress
= try_to_free_pages(zonelist
, order
, gfp_mask
, nodemask
);
2385 current
->reclaim_state
= NULL
;
2386 lockdep_clear_current_reclaim_state();
2387 current
->flags
&= ~PF_MEMALLOC
;
2394 /* The really slow allocator path where we enter direct reclaim */
2395 static inline struct page
*
2396 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
2397 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2398 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2399 int classzone_idx
, int migratetype
, unsigned long *did_some_progress
)
2401 struct page
*page
= NULL
;
2402 bool drained
= false;
2404 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, zonelist
,
2406 if (unlikely(!(*did_some_progress
)))
2409 /* After successful reclaim, reconsider all zones for allocation */
2410 if (IS_ENABLED(CONFIG_NUMA
))
2411 zlc_clear_zones_full(zonelist
);
2414 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
2415 zonelist
, high_zoneidx
,
2416 alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2417 preferred_zone
, classzone_idx
,
2421 * If an allocation failed after direct reclaim, it could be because
2422 * pages are pinned on the per-cpu lists. Drain them and try again
2424 if (!page
&& !drained
) {
2434 * This is called in the allocator slow-path if the allocation request is of
2435 * sufficient urgency to ignore watermarks and take other desperate measures
2437 static inline struct page
*
2438 __alloc_pages_high_priority(gfp_t gfp_mask
, unsigned int order
,
2439 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2440 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2441 int classzone_idx
, int migratetype
)
2446 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
2447 zonelist
, high_zoneidx
, ALLOC_NO_WATERMARKS
,
2448 preferred_zone
, classzone_idx
, migratetype
);
2450 if (!page
&& gfp_mask
& __GFP_NOFAIL
)
2451 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2452 } while (!page
&& (gfp_mask
& __GFP_NOFAIL
));
2457 static void wake_all_kswapds(unsigned int order
,
2458 struct zonelist
*zonelist
,
2459 enum zone_type high_zoneidx
,
2460 struct zone
*preferred_zone
)
2465 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
)
2466 wakeup_kswapd(zone
, order
, zone_idx(preferred_zone
));
2470 gfp_to_alloc_flags(gfp_t gfp_mask
)
2472 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
2473 const bool atomic
= !(gfp_mask
& (__GFP_WAIT
| __GFP_NO_KSWAPD
));
2475 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2476 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
2479 * The caller may dip into page reserves a bit more if the caller
2480 * cannot run direct reclaim, or if the caller has realtime scheduling
2481 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2482 * set both ALLOC_HARDER (atomic == true) and ALLOC_HIGH (__GFP_HIGH).
2484 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
2488 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
2489 * if it can't schedule.
2491 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2492 alloc_flags
|= ALLOC_HARDER
;
2494 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
2495 * comment for __cpuset_node_allowed_softwall().
2497 alloc_flags
&= ~ALLOC_CPUSET
;
2498 } else if (unlikely(rt_task(current
)) && !in_interrupt())
2499 alloc_flags
|= ALLOC_HARDER
;
2501 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
2502 if (gfp_mask
& __GFP_MEMALLOC
)
2503 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2504 else if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
2505 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2506 else if (!in_interrupt() &&
2507 ((current
->flags
& PF_MEMALLOC
) ||
2508 unlikely(test_thread_flag(TIF_MEMDIE
))))
2509 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2512 if (allocflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
2513 alloc_flags
|= ALLOC_CMA
;
2518 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
2520 return !!(gfp_to_alloc_flags(gfp_mask
) & ALLOC_NO_WATERMARKS
);
2523 static inline struct page
*
2524 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
2525 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2526 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2527 int classzone_idx
, int migratetype
)
2529 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
2530 struct page
*page
= NULL
;
2532 unsigned long pages_reclaimed
= 0;
2533 unsigned long did_some_progress
;
2534 enum migrate_mode migration_mode
= MIGRATE_ASYNC
;
2535 bool deferred_compaction
= false;
2536 bool contended_compaction
= false;
2539 * In the slowpath, we sanity check order to avoid ever trying to
2540 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2541 * be using allocators in order of preference for an area that is
2544 if (order
>= MAX_ORDER
) {
2545 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
2550 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
2551 * __GFP_NOWARN set) should not cause reclaim since the subsystem
2552 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
2553 * using a larger set of nodes after it has established that the
2554 * allowed per node queues are empty and that nodes are
2557 if (IS_ENABLED(CONFIG_NUMA
) &&
2558 (gfp_mask
& GFP_THISNODE
) == GFP_THISNODE
)
2562 if (!(gfp_mask
& __GFP_NO_KSWAPD
))
2563 wake_all_kswapds(order
, zonelist
, high_zoneidx
, preferred_zone
);
2566 * OK, we're below the kswapd watermark and have kicked background
2567 * reclaim. Now things get more complex, so set up alloc_flags according
2568 * to how we want to proceed.
2570 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
2573 * Find the true preferred zone if the allocation is unconstrained by
2576 if (!(alloc_flags
& ALLOC_CPUSET
) && !nodemask
) {
2577 struct zoneref
*preferred_zoneref
;
2578 preferred_zoneref
= first_zones_zonelist(zonelist
, high_zoneidx
,
2579 NULL
, &preferred_zone
);
2580 classzone_idx
= zonelist_zone_idx(preferred_zoneref
);
2584 /* This is the last chance, in general, before the goto nopage. */
2585 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
, zonelist
,
2586 high_zoneidx
, alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2587 preferred_zone
, classzone_idx
, migratetype
);
2591 /* Allocate without watermarks if the context allows */
2592 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
2594 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
2595 * the allocation is high priority and these type of
2596 * allocations are system rather than user orientated
2598 zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
2600 page
= __alloc_pages_high_priority(gfp_mask
, order
,
2601 zonelist
, high_zoneidx
, nodemask
,
2602 preferred_zone
, classzone_idx
, migratetype
);
2608 /* Atomic allocations - we can't balance anything */
2611 * All existing users of the deprecated __GFP_NOFAIL are
2612 * blockable, so warn of any new users that actually allow this
2613 * type of allocation to fail.
2615 WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
);
2619 /* Avoid recursion of direct reclaim */
2620 if (current
->flags
& PF_MEMALLOC
)
2623 /* Avoid allocations with no watermarks from looping endlessly */
2624 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
2628 * Try direct compaction. The first pass is asynchronous. Subsequent
2629 * attempts after direct reclaim are synchronous
2631 page
= __alloc_pages_direct_compact(gfp_mask
, order
, zonelist
,
2632 high_zoneidx
, nodemask
, alloc_flags
,
2634 classzone_idx
, migratetype
,
2635 migration_mode
, &contended_compaction
,
2636 &deferred_compaction
,
2637 &did_some_progress
);
2642 * If compaction is deferred for high-order allocations, it is because
2643 * sync compaction recently failed. In this is the case and the caller
2644 * requested a movable allocation that does not heavily disrupt the
2645 * system then fail the allocation instead of entering direct reclaim.
2647 if ((deferred_compaction
|| contended_compaction
) &&
2648 (gfp_mask
& __GFP_NO_KSWAPD
))
2652 * It can become very expensive to allocate transparent hugepages at
2653 * fault, so use asynchronous memory compaction for THP unless it is
2654 * khugepaged trying to collapse.
2656 if ((gfp_mask
& GFP_TRANSHUGE
) != GFP_TRANSHUGE
||
2657 (current
->flags
& PF_KTHREAD
))
2658 migration_mode
= MIGRATE_SYNC_LIGHT
;
2660 /* Try direct reclaim and then allocating */
2661 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
,
2662 zonelist
, high_zoneidx
,
2664 alloc_flags
, preferred_zone
,
2665 classzone_idx
, migratetype
,
2666 &did_some_progress
);
2671 * If we failed to make any progress reclaiming, then we are
2672 * running out of options and have to consider going OOM
2674 if (!did_some_progress
) {
2675 if (oom_gfp_allowed(gfp_mask
)) {
2676 if (oom_killer_disabled
)
2678 /* Coredumps can quickly deplete all memory reserves */
2679 if ((current
->flags
& PF_DUMPCORE
) &&
2680 !(gfp_mask
& __GFP_NOFAIL
))
2682 page
= __alloc_pages_may_oom(gfp_mask
, order
,
2683 zonelist
, high_zoneidx
,
2684 nodemask
, preferred_zone
,
2685 classzone_idx
, migratetype
);
2689 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2691 * The oom killer is not called for high-order
2692 * allocations that may fail, so if no progress
2693 * is being made, there are no other options and
2694 * retrying is unlikely to help.
2696 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2699 * The oom killer is not called for lowmem
2700 * allocations to prevent needlessly killing
2703 if (high_zoneidx
< ZONE_NORMAL
)
2711 /* Check if we should retry the allocation */
2712 pages_reclaimed
+= did_some_progress
;
2713 if (should_alloc_retry(gfp_mask
, order
, did_some_progress
,
2715 /* Wait for some write requests to complete then retry */
2716 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2720 * High-order allocations do not necessarily loop after
2721 * direct reclaim and reclaim/compaction depends on compaction
2722 * being called after reclaim so call directly if necessary
2724 page
= __alloc_pages_direct_compact(gfp_mask
, order
, zonelist
,
2725 high_zoneidx
, nodemask
, alloc_flags
,
2727 classzone_idx
, migratetype
,
2728 migration_mode
, &contended_compaction
,
2729 &deferred_compaction
,
2730 &did_some_progress
);
2736 warn_alloc_failed(gfp_mask
, order
, NULL
);
2739 if (kmemcheck_enabled
)
2740 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
2746 * This is the 'heart' of the zoned buddy allocator.
2749 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
2750 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
2752 enum zone_type high_zoneidx
= gfp_zone(gfp_mask
);
2753 struct zone
*preferred_zone
;
2754 struct zoneref
*preferred_zoneref
;
2755 struct page
*page
= NULL
;
2756 int migratetype
= allocflags_to_migratetype(gfp_mask
);
2757 unsigned int cpuset_mems_cookie
;
2758 int alloc_flags
= ALLOC_WMARK_LOW
|ALLOC_CPUSET
|ALLOC_FAIR
;
2761 gfp_mask
&= gfp_allowed_mask
;
2763 lockdep_trace_alloc(gfp_mask
);
2765 might_sleep_if(gfp_mask
& __GFP_WAIT
);
2767 if (should_fail_alloc_page(gfp_mask
, order
))
2771 * Check the zones suitable for the gfp_mask contain at least one
2772 * valid zone. It's possible to have an empty zonelist as a result
2773 * of GFP_THISNODE and a memoryless node
2775 if (unlikely(!zonelist
->_zonerefs
->zone
))
2779 cpuset_mems_cookie
= read_mems_allowed_begin();
2781 /* The preferred zone is used for statistics later */
2782 preferred_zoneref
= first_zones_zonelist(zonelist
, high_zoneidx
,
2783 nodemask
? : &cpuset_current_mems_allowed
,
2785 if (!preferred_zone
)
2787 classzone_idx
= zonelist_zone_idx(preferred_zoneref
);
2790 if (allocflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
2791 alloc_flags
|= ALLOC_CMA
;
2793 /* First allocation attempt */
2794 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
, order
,
2795 zonelist
, high_zoneidx
, alloc_flags
,
2796 preferred_zone
, classzone_idx
, migratetype
);
2797 if (unlikely(!page
)) {
2799 * Runtime PM, block IO and its error handling path
2800 * can deadlock because I/O on the device might not
2803 gfp_mask
= memalloc_noio_flags(gfp_mask
);
2804 page
= __alloc_pages_slowpath(gfp_mask
, order
,
2805 zonelist
, high_zoneidx
, nodemask
,
2806 preferred_zone
, classzone_idx
, migratetype
);
2809 trace_mm_page_alloc(page
, order
, gfp_mask
, migratetype
);
2813 * When updating a task's mems_allowed, it is possible to race with
2814 * parallel threads in such a way that an allocation can fail while
2815 * the mask is being updated. If a page allocation is about to fail,
2816 * check if the cpuset changed during allocation and if so, retry.
2818 if (unlikely(!page
&& read_mems_allowed_retry(cpuset_mems_cookie
)))
2823 EXPORT_SYMBOL(__alloc_pages_nodemask
);
2826 * Common helper functions.
2828 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
2833 * __get_free_pages() returns a 32-bit address, which cannot represent
2836 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
2838 page
= alloc_pages(gfp_mask
, order
);
2841 return (unsigned long) page_address(page
);
2843 EXPORT_SYMBOL(__get_free_pages
);
2845 unsigned long get_zeroed_page(gfp_t gfp_mask
)
2847 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
2849 EXPORT_SYMBOL(get_zeroed_page
);
2851 void __free_pages(struct page
*page
, unsigned int order
)
2853 if (put_page_testzero(page
)) {
2855 free_hot_cold_page(page
, false);
2857 __free_pages_ok(page
, order
);
2861 EXPORT_SYMBOL(__free_pages
);
2863 void free_pages(unsigned long addr
, unsigned int order
)
2866 VM_BUG_ON(!virt_addr_valid((void *)addr
));
2867 __free_pages(virt_to_page((void *)addr
), order
);
2871 EXPORT_SYMBOL(free_pages
);
2874 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
2875 * of the current memory cgroup.
2877 * It should be used when the caller would like to use kmalloc, but since the
2878 * allocation is large, it has to fall back to the page allocator.
2880 struct page
*alloc_kmem_pages(gfp_t gfp_mask
, unsigned int order
)
2883 struct mem_cgroup
*memcg
= NULL
;
2885 if (!memcg_kmem_newpage_charge(gfp_mask
, &memcg
, order
))
2887 page
= alloc_pages(gfp_mask
, order
);
2888 memcg_kmem_commit_charge(page
, memcg
, order
);
2892 struct page
*alloc_kmem_pages_node(int nid
, gfp_t gfp_mask
, unsigned int order
)
2895 struct mem_cgroup
*memcg
= NULL
;
2897 if (!memcg_kmem_newpage_charge(gfp_mask
, &memcg
, order
))
2899 page
= alloc_pages_node(nid
, gfp_mask
, order
);
2900 memcg_kmem_commit_charge(page
, memcg
, order
);
2905 * __free_kmem_pages and free_kmem_pages will free pages allocated with
2908 void __free_kmem_pages(struct page
*page
, unsigned int order
)
2910 memcg_kmem_uncharge_pages(page
, order
);
2911 __free_pages(page
, order
);
2914 void free_kmem_pages(unsigned long addr
, unsigned int order
)
2917 VM_BUG_ON(!virt_addr_valid((void *)addr
));
2918 __free_kmem_pages(virt_to_page((void *)addr
), order
);
2922 static void *make_alloc_exact(unsigned long addr
, unsigned order
, size_t size
)
2925 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
2926 unsigned long used
= addr
+ PAGE_ALIGN(size
);
2928 split_page(virt_to_page((void *)addr
), order
);
2929 while (used
< alloc_end
) {
2934 return (void *)addr
;
2938 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2939 * @size: the number of bytes to allocate
2940 * @gfp_mask: GFP flags for the allocation
2942 * This function is similar to alloc_pages(), except that it allocates the
2943 * minimum number of pages to satisfy the request. alloc_pages() can only
2944 * allocate memory in power-of-two pages.
2946 * This function is also limited by MAX_ORDER.
2948 * Memory allocated by this function must be released by free_pages_exact().
2950 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
2952 unsigned int order
= get_order(size
);
2955 addr
= __get_free_pages(gfp_mask
, order
);
2956 return make_alloc_exact(addr
, order
, size
);
2958 EXPORT_SYMBOL(alloc_pages_exact
);
2961 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
2963 * @nid: the preferred node ID where memory should be allocated
2964 * @size: the number of bytes to allocate
2965 * @gfp_mask: GFP flags for the allocation
2967 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
2969 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
2972 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
2974 unsigned order
= get_order(size
);
2975 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
2978 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
2982 * free_pages_exact - release memory allocated via alloc_pages_exact()
2983 * @virt: the value returned by alloc_pages_exact.
2984 * @size: size of allocation, same value as passed to alloc_pages_exact().
2986 * Release the memory allocated by a previous call to alloc_pages_exact.
2988 void free_pages_exact(void *virt
, size_t size
)
2990 unsigned long addr
= (unsigned long)virt
;
2991 unsigned long end
= addr
+ PAGE_ALIGN(size
);
2993 while (addr
< end
) {
2998 EXPORT_SYMBOL(free_pages_exact
);
3001 * nr_free_zone_pages - count number of pages beyond high watermark
3002 * @offset: The zone index of the highest zone
3004 * nr_free_zone_pages() counts the number of counts pages which are beyond the
3005 * high watermark within all zones at or below a given zone index. For each
3006 * zone, the number of pages is calculated as:
3007 * managed_pages - high_pages
3009 static unsigned long nr_free_zone_pages(int offset
)
3014 /* Just pick one node, since fallback list is circular */
3015 unsigned long sum
= 0;
3017 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
3019 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
3020 unsigned long size
= zone
->managed_pages
;
3021 unsigned long high
= high_wmark_pages(zone
);
3030 * nr_free_buffer_pages - count number of pages beyond high watermark
3032 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3033 * watermark within ZONE_DMA and ZONE_NORMAL.
3035 unsigned long nr_free_buffer_pages(void)
3037 return nr_free_zone_pages(gfp_zone(GFP_USER
));
3039 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
3042 * nr_free_pagecache_pages - count number of pages beyond high watermark
3044 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3045 * high watermark within all zones.
3047 unsigned long nr_free_pagecache_pages(void)
3049 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
3052 static inline void show_node(struct zone
*zone
)
3054 if (IS_ENABLED(CONFIG_NUMA
))
3055 printk("Node %d ", zone_to_nid(zone
));
3058 void si_meminfo(struct sysinfo
*val
)
3060 val
->totalram
= totalram_pages
;
3061 val
->sharedram
= global_page_state(NR_SHMEM
);
3062 val
->freeram
= global_page_state(NR_FREE_PAGES
);
3063 val
->bufferram
= nr_blockdev_pages();
3064 val
->totalhigh
= totalhigh_pages
;
3065 val
->freehigh
= nr_free_highpages();
3066 val
->mem_unit
= PAGE_SIZE
;
3069 EXPORT_SYMBOL(si_meminfo
);
3072 void si_meminfo_node(struct sysinfo
*val
, int nid
)
3074 int zone_type
; /* needs to be signed */
3075 unsigned long managed_pages
= 0;
3076 pg_data_t
*pgdat
= NODE_DATA(nid
);
3078 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
3079 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
3080 val
->totalram
= managed_pages
;
3081 val
->sharedram
= node_page_state(nid
, NR_SHMEM
);
3082 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
3083 #ifdef CONFIG_HIGHMEM
3084 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].managed_pages
;
3085 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
3091 val
->mem_unit
= PAGE_SIZE
;
3096 * Determine whether the node should be displayed or not, depending on whether
3097 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3099 bool skip_free_areas_node(unsigned int flags
, int nid
)
3102 unsigned int cpuset_mems_cookie
;
3104 if (!(flags
& SHOW_MEM_FILTER_NODES
))
3108 cpuset_mems_cookie
= read_mems_allowed_begin();
3109 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
3110 } while (read_mems_allowed_retry(cpuset_mems_cookie
));
3115 #define K(x) ((x) << (PAGE_SHIFT-10))
3117 static void show_migration_types(unsigned char type
)
3119 static const char types
[MIGRATE_TYPES
] = {
3120 [MIGRATE_UNMOVABLE
] = 'U',
3121 [MIGRATE_RECLAIMABLE
] = 'E',
3122 [MIGRATE_MOVABLE
] = 'M',
3123 [MIGRATE_RESERVE
] = 'R',
3125 [MIGRATE_CMA
] = 'C',
3127 #ifdef CONFIG_MEMORY_ISOLATION
3128 [MIGRATE_ISOLATE
] = 'I',
3131 char tmp
[MIGRATE_TYPES
+ 1];
3135 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
3136 if (type
& (1 << i
))
3141 printk("(%s) ", tmp
);
3145 * Show free area list (used inside shift_scroll-lock stuff)
3146 * We also calculate the percentage fragmentation. We do this by counting the
3147 * memory on each free list with the exception of the first item on the list.
3148 * Suppresses nodes that are not allowed by current's cpuset if
3149 * SHOW_MEM_FILTER_NODES is passed.
3151 void show_free_areas(unsigned int filter
)
3156 for_each_populated_zone(zone
) {
3157 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3160 printk("%s per-cpu:\n", zone
->name
);
3162 for_each_online_cpu(cpu
) {
3163 struct per_cpu_pageset
*pageset
;
3165 pageset
= per_cpu_ptr(zone
->pageset
, cpu
);
3167 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
3168 cpu
, pageset
->pcp
.high
,
3169 pageset
->pcp
.batch
, pageset
->pcp
.count
);
3173 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3174 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3176 " dirty:%lu writeback:%lu unstable:%lu\n"
3177 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3178 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3180 global_page_state(NR_ACTIVE_ANON
),
3181 global_page_state(NR_INACTIVE_ANON
),
3182 global_page_state(NR_ISOLATED_ANON
),
3183 global_page_state(NR_ACTIVE_FILE
),
3184 global_page_state(NR_INACTIVE_FILE
),
3185 global_page_state(NR_ISOLATED_FILE
),
3186 global_page_state(NR_UNEVICTABLE
),
3187 global_page_state(NR_FILE_DIRTY
),
3188 global_page_state(NR_WRITEBACK
),
3189 global_page_state(NR_UNSTABLE_NFS
),
3190 global_page_state(NR_FREE_PAGES
),
3191 global_page_state(NR_SLAB_RECLAIMABLE
),
3192 global_page_state(NR_SLAB_UNRECLAIMABLE
),
3193 global_page_state(NR_FILE_MAPPED
),
3194 global_page_state(NR_SHMEM
),
3195 global_page_state(NR_PAGETABLE
),
3196 global_page_state(NR_BOUNCE
),
3197 global_page_state(NR_FREE_CMA_PAGES
));
3199 for_each_populated_zone(zone
) {
3202 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3210 " active_anon:%lukB"
3211 " inactive_anon:%lukB"
3212 " active_file:%lukB"
3213 " inactive_file:%lukB"
3214 " unevictable:%lukB"
3215 " isolated(anon):%lukB"
3216 " isolated(file):%lukB"
3224 " slab_reclaimable:%lukB"
3225 " slab_unreclaimable:%lukB"
3226 " kernel_stack:%lukB"
3231 " writeback_tmp:%lukB"
3232 " pages_scanned:%lu"
3233 " all_unreclaimable? %s"
3236 K(zone_page_state(zone
, NR_FREE_PAGES
)),
3237 K(min_wmark_pages(zone
)),
3238 K(low_wmark_pages(zone
)),
3239 K(high_wmark_pages(zone
)),
3240 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
3241 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
3242 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
3243 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
3244 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
3245 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
3246 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
3247 K(zone
->present_pages
),
3248 K(zone
->managed_pages
),
3249 K(zone_page_state(zone
, NR_MLOCK
)),
3250 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
3251 K(zone_page_state(zone
, NR_WRITEBACK
)),
3252 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
3253 K(zone_page_state(zone
, NR_SHMEM
)),
3254 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
3255 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
3256 zone_page_state(zone
, NR_KERNEL_STACK
) *
3258 K(zone_page_state(zone
, NR_PAGETABLE
)),
3259 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
3260 K(zone_page_state(zone
, NR_BOUNCE
)),
3261 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)),
3262 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
3263 K(zone_page_state(zone
, NR_PAGES_SCANNED
)),
3264 (!zone_reclaimable(zone
) ? "yes" : "no")
3266 printk("lowmem_reserve[]:");
3267 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3268 printk(" %ld", zone
->lowmem_reserve
[i
]);
3272 for_each_populated_zone(zone
) {
3273 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
3274 unsigned char types
[MAX_ORDER
];
3276 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3279 printk("%s: ", zone
->name
);
3281 spin_lock_irqsave(&zone
->lock
, flags
);
3282 for (order
= 0; order
< MAX_ORDER
; order
++) {
3283 struct free_area
*area
= &zone
->free_area
[order
];
3286 nr
[order
] = area
->nr_free
;
3287 total
+= nr
[order
] << order
;
3290 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
3291 if (!list_empty(&area
->free_list
[type
]))
3292 types
[order
] |= 1 << type
;
3295 spin_unlock_irqrestore(&zone
->lock
, flags
);
3296 for (order
= 0; order
< MAX_ORDER
; order
++) {
3297 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
3299 show_migration_types(types
[order
]);
3301 printk("= %lukB\n", K(total
));
3304 hugetlb_show_meminfo();
3306 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
3308 show_swap_cache_info();
3311 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
3313 zoneref
->zone
= zone
;
3314 zoneref
->zone_idx
= zone_idx(zone
);
3318 * Builds allocation fallback zone lists.
3320 * Add all populated zones of a node to the zonelist.
3322 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
3326 enum zone_type zone_type
= MAX_NR_ZONES
;
3330 zone
= pgdat
->node_zones
+ zone_type
;
3331 if (populated_zone(zone
)) {
3332 zoneref_set_zone(zone
,
3333 &zonelist
->_zonerefs
[nr_zones
++]);
3334 check_highest_zone(zone_type
);
3336 } while (zone_type
);
3344 * 0 = automatic detection of better ordering.
3345 * 1 = order by ([node] distance, -zonetype)
3346 * 2 = order by (-zonetype, [node] distance)
3348 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
3349 * the same zonelist. So only NUMA can configure this param.
3351 #define ZONELIST_ORDER_DEFAULT 0
3352 #define ZONELIST_ORDER_NODE 1
3353 #define ZONELIST_ORDER_ZONE 2
3355 /* zonelist order in the kernel.
3356 * set_zonelist_order() will set this to NODE or ZONE.
3358 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3359 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
3363 /* The value user specified ....changed by config */
3364 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3365 /* string for sysctl */
3366 #define NUMA_ZONELIST_ORDER_LEN 16
3367 char numa_zonelist_order
[16] = "default";
3370 * interface for configure zonelist ordering.
3371 * command line option "numa_zonelist_order"
3372 * = "[dD]efault - default, automatic configuration.
3373 * = "[nN]ode - order by node locality, then by zone within node
3374 * = "[zZ]one - order by zone, then by locality within zone
3377 static int __parse_numa_zonelist_order(char *s
)
3379 if (*s
== 'd' || *s
== 'D') {
3380 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3381 } else if (*s
== 'n' || *s
== 'N') {
3382 user_zonelist_order
= ZONELIST_ORDER_NODE
;
3383 } else if (*s
== 'z' || *s
== 'Z') {
3384 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
3387 "Ignoring invalid numa_zonelist_order value: "
3394 static __init
int setup_numa_zonelist_order(char *s
)
3401 ret
= __parse_numa_zonelist_order(s
);
3403 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
3407 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
3410 * sysctl handler for numa_zonelist_order
3412 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
3413 void __user
*buffer
, size_t *length
,
3416 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
3418 static DEFINE_MUTEX(zl_order_mutex
);
3420 mutex_lock(&zl_order_mutex
);
3422 if (strlen((char *)table
->data
) >= NUMA_ZONELIST_ORDER_LEN
) {
3426 strcpy(saved_string
, (char *)table
->data
);
3428 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
3432 int oldval
= user_zonelist_order
;
3434 ret
= __parse_numa_zonelist_order((char *)table
->data
);
3437 * bogus value. restore saved string
3439 strncpy((char *)table
->data
, saved_string
,
3440 NUMA_ZONELIST_ORDER_LEN
);
3441 user_zonelist_order
= oldval
;
3442 } else if (oldval
!= user_zonelist_order
) {
3443 mutex_lock(&zonelists_mutex
);
3444 build_all_zonelists(NULL
, NULL
);
3445 mutex_unlock(&zonelists_mutex
);
3449 mutex_unlock(&zl_order_mutex
);
3454 #define MAX_NODE_LOAD (nr_online_nodes)
3455 static int node_load
[MAX_NUMNODES
];
3458 * find_next_best_node - find the next node that should appear in a given node's fallback list
3459 * @node: node whose fallback list we're appending
3460 * @used_node_mask: nodemask_t of already used nodes
3462 * We use a number of factors to determine which is the next node that should
3463 * appear on a given node's fallback list. The node should not have appeared
3464 * already in @node's fallback list, and it should be the next closest node
3465 * according to the distance array (which contains arbitrary distance values
3466 * from each node to each node in the system), and should also prefer nodes
3467 * with no CPUs, since presumably they'll have very little allocation pressure
3468 * on them otherwise.
3469 * It returns -1 if no node is found.
3471 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
3474 int min_val
= INT_MAX
;
3475 int best_node
= NUMA_NO_NODE
;
3476 const struct cpumask
*tmp
= cpumask_of_node(0);
3478 /* Use the local node if we haven't already */
3479 if (!node_isset(node
, *used_node_mask
)) {
3480 node_set(node
, *used_node_mask
);
3484 for_each_node_state(n
, N_MEMORY
) {
3486 /* Don't want a node to appear more than once */
3487 if (node_isset(n
, *used_node_mask
))
3490 /* Use the distance array to find the distance */
3491 val
= node_distance(node
, n
);
3493 /* Penalize nodes under us ("prefer the next node") */
3496 /* Give preference to headless and unused nodes */
3497 tmp
= cpumask_of_node(n
);
3498 if (!cpumask_empty(tmp
))
3499 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
3501 /* Slight preference for less loaded node */
3502 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
3503 val
+= node_load
[n
];
3505 if (val
< min_val
) {
3512 node_set(best_node
, *used_node_mask
);
3519 * Build zonelists ordered by node and zones within node.
3520 * This results in maximum locality--normal zone overflows into local
3521 * DMA zone, if any--but risks exhausting DMA zone.
3523 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
3526 struct zonelist
*zonelist
;
3528 zonelist
= &pgdat
->node_zonelists
[0];
3529 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
3531 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
3532 zonelist
->_zonerefs
[j
].zone
= NULL
;
3533 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3537 * Build gfp_thisnode zonelists
3539 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
3542 struct zonelist
*zonelist
;
3544 zonelist
= &pgdat
->node_zonelists
[1];
3545 j
= build_zonelists_node(pgdat
, zonelist
, 0);
3546 zonelist
->_zonerefs
[j
].zone
= NULL
;
3547 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3551 * Build zonelists ordered by zone and nodes within zones.
3552 * This results in conserving DMA zone[s] until all Normal memory is
3553 * exhausted, but results in overflowing to remote node while memory
3554 * may still exist in local DMA zone.
3556 static int node_order
[MAX_NUMNODES
];
3558 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
3561 int zone_type
; /* needs to be signed */
3563 struct zonelist
*zonelist
;
3565 zonelist
= &pgdat
->node_zonelists
[0];
3567 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
3568 for (j
= 0; j
< nr_nodes
; j
++) {
3569 node
= node_order
[j
];
3570 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
3571 if (populated_zone(z
)) {
3573 &zonelist
->_zonerefs
[pos
++]);
3574 check_highest_zone(zone_type
);
3578 zonelist
->_zonerefs
[pos
].zone
= NULL
;
3579 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
3582 static int default_zonelist_order(void)
3585 unsigned long low_kmem_size
, total_size
;
3589 * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
3590 * If they are really small and used heavily, the system can fall
3591 * into OOM very easily.
3592 * This function detect ZONE_DMA/DMA32 size and configures zone order.
3594 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
3597 for_each_online_node(nid
) {
3598 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
3599 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
3600 if (populated_zone(z
)) {
3601 if (zone_type
< ZONE_NORMAL
)
3602 low_kmem_size
+= z
->managed_pages
;
3603 total_size
+= z
->managed_pages
;
3604 } else if (zone_type
== ZONE_NORMAL
) {
3606 * If any node has only lowmem, then node order
3607 * is preferred to allow kernel allocations
3608 * locally; otherwise, they can easily infringe
3609 * on other nodes when there is an abundance of
3610 * lowmem available to allocate from.
3612 return ZONELIST_ORDER_NODE
;
3616 if (!low_kmem_size
|| /* there are no DMA area. */
3617 low_kmem_size
> total_size
/2) /* DMA/DMA32 is big. */
3618 return ZONELIST_ORDER_NODE
;
3620 * look into each node's config.
3621 * If there is a node whose DMA/DMA32 memory is very big area on
3622 * local memory, NODE_ORDER may be suitable.
3624 average_size
= total_size
/
3625 (nodes_weight(node_states
[N_MEMORY
]) + 1);
3626 for_each_online_node(nid
) {
3629 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
3630 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
3631 if (populated_zone(z
)) {
3632 if (zone_type
< ZONE_NORMAL
)
3633 low_kmem_size
+= z
->present_pages
;
3634 total_size
+= z
->present_pages
;
3637 if (low_kmem_size
&&
3638 total_size
> average_size
&& /* ignore small node */
3639 low_kmem_size
> total_size
* 70/100)
3640 return ZONELIST_ORDER_NODE
;
3642 return ZONELIST_ORDER_ZONE
;
3645 static void set_zonelist_order(void)
3647 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
3648 current_zonelist_order
= default_zonelist_order();
3650 current_zonelist_order
= user_zonelist_order
;
3653 static void build_zonelists(pg_data_t
*pgdat
)
3657 nodemask_t used_mask
;
3658 int local_node
, prev_node
;
3659 struct zonelist
*zonelist
;
3660 int order
= current_zonelist_order
;
3662 /* initialize zonelists */
3663 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
3664 zonelist
= pgdat
->node_zonelists
+ i
;
3665 zonelist
->_zonerefs
[0].zone
= NULL
;
3666 zonelist
->_zonerefs
[0].zone_idx
= 0;
3669 /* NUMA-aware ordering of nodes */
3670 local_node
= pgdat
->node_id
;
3671 load
= nr_online_nodes
;
3672 prev_node
= local_node
;
3673 nodes_clear(used_mask
);
3675 memset(node_order
, 0, sizeof(node_order
));
3678 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
3680 * We don't want to pressure a particular node.
3681 * So adding penalty to the first node in same
3682 * distance group to make it round-robin.
3684 if (node_distance(local_node
, node
) !=
3685 node_distance(local_node
, prev_node
))
3686 node_load
[node
] = load
;
3690 if (order
== ZONELIST_ORDER_NODE
)
3691 build_zonelists_in_node_order(pgdat
, node
);
3693 node_order
[j
++] = node
; /* remember order */
3696 if (order
== ZONELIST_ORDER_ZONE
) {
3697 /* calculate node order -- i.e., DMA last! */
3698 build_zonelists_in_zone_order(pgdat
, j
);
3701 build_thisnode_zonelists(pgdat
);
3704 /* Construct the zonelist performance cache - see further mmzone.h */
3705 static void build_zonelist_cache(pg_data_t
*pgdat
)
3707 struct zonelist
*zonelist
;
3708 struct zonelist_cache
*zlc
;
3711 zonelist
= &pgdat
->node_zonelists
[0];
3712 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
3713 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
3714 for (z
= zonelist
->_zonerefs
; z
->zone
; z
++)
3715 zlc
->z_to_n
[z
- zonelist
->_zonerefs
] = zonelist_node_idx(z
);
3718 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3720 * Return node id of node used for "local" allocations.
3721 * I.e., first node id of first zone in arg node's generic zonelist.
3722 * Used for initializing percpu 'numa_mem', which is used primarily
3723 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
3725 int local_memory_node(int node
)
3729 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
3730 gfp_zone(GFP_KERNEL
),
3737 #else /* CONFIG_NUMA */
3739 static void set_zonelist_order(void)
3741 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
3744 static void build_zonelists(pg_data_t
*pgdat
)
3746 int node
, local_node
;
3748 struct zonelist
*zonelist
;
3750 local_node
= pgdat
->node_id
;
3752 zonelist
= &pgdat
->node_zonelists
[0];
3753 j
= build_zonelists_node(pgdat
, zonelist
, 0);
3756 * Now we build the zonelist so that it contains the zones
3757 * of all the other nodes.
3758 * We don't want to pressure a particular node, so when
3759 * building the zones for node N, we make sure that the
3760 * zones coming right after the local ones are those from
3761 * node N+1 (modulo N)
3763 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
3764 if (!node_online(node
))
3766 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
3768 for (node
= 0; node
< local_node
; node
++) {
3769 if (!node_online(node
))
3771 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
3774 zonelist
->_zonerefs
[j
].zone
= NULL
;
3775 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3778 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3779 static void build_zonelist_cache(pg_data_t
*pgdat
)
3781 pgdat
->node_zonelists
[0].zlcache_ptr
= NULL
;
3784 #endif /* CONFIG_NUMA */
3787 * Boot pageset table. One per cpu which is going to be used for all
3788 * zones and all nodes. The parameters will be set in such a way
3789 * that an item put on a list will immediately be handed over to
3790 * the buddy list. This is safe since pageset manipulation is done
3791 * with interrupts disabled.
3793 * The boot_pagesets must be kept even after bootup is complete for
3794 * unused processors and/or zones. They do play a role for bootstrapping
3795 * hotplugged processors.
3797 * zoneinfo_show() and maybe other functions do
3798 * not check if the processor is online before following the pageset pointer.
3799 * Other parts of the kernel may not check if the zone is available.
3801 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
3802 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
3803 static void setup_zone_pageset(struct zone
*zone
);
3806 * Global mutex to protect against size modification of zonelists
3807 * as well as to serialize pageset setup for the new populated zone.
3809 DEFINE_MUTEX(zonelists_mutex
);
3811 /* return values int ....just for stop_machine() */
3812 static int __build_all_zonelists(void *data
)
3816 pg_data_t
*self
= data
;
3819 memset(node_load
, 0, sizeof(node_load
));
3822 if (self
&& !node_online(self
->node_id
)) {
3823 build_zonelists(self
);
3824 build_zonelist_cache(self
);
3827 for_each_online_node(nid
) {
3828 pg_data_t
*pgdat
= NODE_DATA(nid
);
3830 build_zonelists(pgdat
);
3831 build_zonelist_cache(pgdat
);
3835 * Initialize the boot_pagesets that are going to be used
3836 * for bootstrapping processors. The real pagesets for
3837 * each zone will be allocated later when the per cpu
3838 * allocator is available.
3840 * boot_pagesets are used also for bootstrapping offline
3841 * cpus if the system is already booted because the pagesets
3842 * are needed to initialize allocators on a specific cpu too.
3843 * F.e. the percpu allocator needs the page allocator which
3844 * needs the percpu allocator in order to allocate its pagesets
3845 * (a chicken-egg dilemma).
3847 for_each_possible_cpu(cpu
) {
3848 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
3850 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3852 * We now know the "local memory node" for each node--
3853 * i.e., the node of the first zone in the generic zonelist.
3854 * Set up numa_mem percpu variable for on-line cpus. During
3855 * boot, only the boot cpu should be on-line; we'll init the
3856 * secondary cpus' numa_mem as they come on-line. During
3857 * node/memory hotplug, we'll fixup all on-line cpus.
3859 if (cpu_online(cpu
))
3860 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
3868 * Called with zonelists_mutex held always
3869 * unless system_state == SYSTEM_BOOTING.
3871 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
3873 set_zonelist_order();
3875 if (system_state
== SYSTEM_BOOTING
) {
3876 __build_all_zonelists(NULL
);
3877 mminit_verify_zonelist();
3878 cpuset_init_current_mems_allowed();
3880 #ifdef CONFIG_MEMORY_HOTPLUG
3882 setup_zone_pageset(zone
);
3884 /* we have to stop all cpus to guarantee there is no user
3886 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
3887 /* cpuset refresh routine should be here */
3889 vm_total_pages
= nr_free_pagecache_pages();
3891 * Disable grouping by mobility if the number of pages in the
3892 * system is too low to allow the mechanism to work. It would be
3893 * more accurate, but expensive to check per-zone. This check is
3894 * made on memory-hotadd so a system can start with mobility
3895 * disabled and enable it later
3897 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
3898 page_group_by_mobility_disabled
= 1;
3900 page_group_by_mobility_disabled
= 0;
3902 printk("Built %i zonelists in %s order, mobility grouping %s. "
3903 "Total pages: %ld\n",
3905 zonelist_order_name
[current_zonelist_order
],
3906 page_group_by_mobility_disabled
? "off" : "on",
3909 printk("Policy zone: %s\n", zone_names
[policy_zone
]);
3914 * Helper functions to size the waitqueue hash table.
3915 * Essentially these want to choose hash table sizes sufficiently
3916 * large so that collisions trying to wait on pages are rare.
3917 * But in fact, the number of active page waitqueues on typical
3918 * systems is ridiculously low, less than 200. So this is even
3919 * conservative, even though it seems large.
3921 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
3922 * waitqueues, i.e. the size of the waitq table given the number of pages.
3924 #define PAGES_PER_WAITQUEUE 256
3926 #ifndef CONFIG_MEMORY_HOTPLUG
3927 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3929 unsigned long size
= 1;
3931 pages
/= PAGES_PER_WAITQUEUE
;
3933 while (size
< pages
)
3937 * Once we have dozens or even hundreds of threads sleeping
3938 * on IO we've got bigger problems than wait queue collision.
3939 * Limit the size of the wait table to a reasonable size.
3941 size
= min(size
, 4096UL);
3943 return max(size
, 4UL);
3947 * A zone's size might be changed by hot-add, so it is not possible to determine
3948 * a suitable size for its wait_table. So we use the maximum size now.
3950 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
3952 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
3953 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
3954 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
3956 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
3957 * or more by the traditional way. (See above). It equals:
3959 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
3960 * ia64(16K page size) : = ( 8G + 4M)byte.
3961 * powerpc (64K page size) : = (32G +16M)byte.
3963 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3970 * This is an integer logarithm so that shifts can be used later
3971 * to extract the more random high bits from the multiplicative
3972 * hash function before the remainder is taken.
3974 static inline unsigned long wait_table_bits(unsigned long size
)
3980 * Check if a pageblock contains reserved pages
3982 static int pageblock_is_reserved(unsigned long start_pfn
, unsigned long end_pfn
)
3986 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
3987 if (!pfn_valid_within(pfn
) || PageReserved(pfn_to_page(pfn
)))
3994 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3995 * of blocks reserved is based on min_wmark_pages(zone). The memory within
3996 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
3997 * higher will lead to a bigger reserve which will get freed as contiguous
3998 * blocks as reclaim kicks in
4000 static void setup_zone_migrate_reserve(struct zone
*zone
)
4002 unsigned long start_pfn
, pfn
, end_pfn
, block_end_pfn
;
4004 unsigned long block_migratetype
;
4009 * Get the start pfn, end pfn and the number of blocks to reserve
4010 * We have to be careful to be aligned to pageblock_nr_pages to
4011 * make sure that we always check pfn_valid for the first page in
4014 start_pfn
= zone
->zone_start_pfn
;
4015 end_pfn
= zone_end_pfn(zone
);
4016 start_pfn
= roundup(start_pfn
, pageblock_nr_pages
);
4017 reserve
= roundup(min_wmark_pages(zone
), pageblock_nr_pages
) >>
4021 * Reserve blocks are generally in place to help high-order atomic
4022 * allocations that are short-lived. A min_free_kbytes value that
4023 * would result in more than 2 reserve blocks for atomic allocations
4024 * is assumed to be in place to help anti-fragmentation for the
4025 * future allocation of hugepages at runtime.
4027 reserve
= min(2, reserve
);
4028 old_reserve
= zone
->nr_migrate_reserve_block
;
4030 /* When memory hot-add, we almost always need to do nothing */
4031 if (reserve
== old_reserve
)
4033 zone
->nr_migrate_reserve_block
= reserve
;
4035 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
4036 if (!pfn_valid(pfn
))
4038 page
= pfn_to_page(pfn
);
4040 /* Watch out for overlapping nodes */
4041 if (page_to_nid(page
) != zone_to_nid(zone
))
4044 block_migratetype
= get_pageblock_migratetype(page
);
4046 /* Only test what is necessary when the reserves are not met */
4049 * Blocks with reserved pages will never free, skip
4052 block_end_pfn
= min(pfn
+ pageblock_nr_pages
, end_pfn
);
4053 if (pageblock_is_reserved(pfn
, block_end_pfn
))
4056 /* If this block is reserved, account for it */
4057 if (block_migratetype
== MIGRATE_RESERVE
) {
4062 /* Suitable for reserving if this block is movable */
4063 if (block_migratetype
== MIGRATE_MOVABLE
) {
4064 set_pageblock_migratetype(page
,
4066 move_freepages_block(zone
, page
,
4071 } else if (!old_reserve
) {
4073 * At boot time we don't need to scan the whole zone
4074 * for turning off MIGRATE_RESERVE.
4080 * If the reserve is met and this is a previous reserved block,
4083 if (block_migratetype
== MIGRATE_RESERVE
) {
4084 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4085 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
4091 * Initially all pages are reserved - free ones are freed
4092 * up by free_all_bootmem() once the early boot process is
4093 * done. Non-atomic initialization, single-pass.
4095 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
4096 unsigned long start_pfn
, enum memmap_context context
)
4099 unsigned long end_pfn
= start_pfn
+ size
;
4103 if (highest_memmap_pfn
< end_pfn
- 1)
4104 highest_memmap_pfn
= end_pfn
- 1;
4106 z
= &NODE_DATA(nid
)->node_zones
[zone
];
4107 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
4109 * There can be holes in boot-time mem_map[]s
4110 * handed to this function. They do not
4111 * exist on hotplugged memory.
4113 if (context
== MEMMAP_EARLY
) {
4114 if (!early_pfn_valid(pfn
))
4116 if (!early_pfn_in_nid(pfn
, nid
))
4119 page
= pfn_to_page(pfn
);
4120 set_page_links(page
, zone
, nid
, pfn
);
4121 mminit_verify_page_links(page
, zone
, nid
, pfn
);
4122 init_page_count(page
);
4123 page_mapcount_reset(page
);
4124 page_cpupid_reset_last(page
);
4125 SetPageReserved(page
);
4127 * Mark the block movable so that blocks are reserved for
4128 * movable at startup. This will force kernel allocations
4129 * to reserve their blocks rather than leaking throughout
4130 * the address space during boot when many long-lived
4131 * kernel allocations are made. Later some blocks near
4132 * the start are marked MIGRATE_RESERVE by
4133 * setup_zone_migrate_reserve()
4135 * bitmap is created for zone's valid pfn range. but memmap
4136 * can be created for invalid pages (for alignment)
4137 * check here not to call set_pageblock_migratetype() against
4140 if ((z
->zone_start_pfn
<= pfn
)
4141 && (pfn
< zone_end_pfn(z
))
4142 && !(pfn
& (pageblock_nr_pages
- 1)))
4143 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4145 INIT_LIST_HEAD(&page
->lru
);
4146 #ifdef WANT_PAGE_VIRTUAL
4147 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
4148 if (!is_highmem_idx(zone
))
4149 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
4154 static void __meminit
zone_init_free_lists(struct zone
*zone
)
4156 unsigned int order
, t
;
4157 for_each_migratetype_order(order
, t
) {
4158 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
4159 zone
->free_area
[order
].nr_free
= 0;
4163 #ifndef __HAVE_ARCH_MEMMAP_INIT
4164 #define memmap_init(size, nid, zone, start_pfn) \
4165 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4168 static int zone_batchsize(struct zone
*zone
)
4174 * The per-cpu-pages pools are set to around 1000th of the
4175 * size of the zone. But no more than 1/2 of a meg.
4177 * OK, so we don't know how big the cache is. So guess.
4179 batch
= zone
->managed_pages
/ 1024;
4180 if (batch
* PAGE_SIZE
> 512 * 1024)
4181 batch
= (512 * 1024) / PAGE_SIZE
;
4182 batch
/= 4; /* We effectively *= 4 below */
4187 * Clamp the batch to a 2^n - 1 value. Having a power
4188 * of 2 value was found to be more likely to have
4189 * suboptimal cache aliasing properties in some cases.
4191 * For example if 2 tasks are alternately allocating
4192 * batches of pages, one task can end up with a lot
4193 * of pages of one half of the possible page colors
4194 * and the other with pages of the other colors.
4196 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
4201 /* The deferral and batching of frees should be suppressed under NOMMU
4204 * The problem is that NOMMU needs to be able to allocate large chunks
4205 * of contiguous memory as there's no hardware page translation to
4206 * assemble apparent contiguous memory from discontiguous pages.
4208 * Queueing large contiguous runs of pages for batching, however,
4209 * causes the pages to actually be freed in smaller chunks. As there
4210 * can be a significant delay between the individual batches being
4211 * recycled, this leads to the once large chunks of space being
4212 * fragmented and becoming unavailable for high-order allocations.
4219 * pcp->high and pcp->batch values are related and dependent on one another:
4220 * ->batch must never be higher then ->high.
4221 * The following function updates them in a safe manner without read side
4224 * Any new users of pcp->batch and pcp->high should ensure they can cope with
4225 * those fields changing asynchronously (acording the the above rule).
4227 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
4228 * outside of boot time (or some other assurance that no concurrent updaters
4231 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
4232 unsigned long batch
)
4234 /* start with a fail safe value for batch */
4238 /* Update high, then batch, in order */
4245 /* a companion to pageset_set_high() */
4246 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
4248 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
4251 static void pageset_init(struct per_cpu_pageset
*p
)
4253 struct per_cpu_pages
*pcp
;
4256 memset(p
, 0, sizeof(*p
));
4260 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
4261 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
4264 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
4267 pageset_set_batch(p
, batch
);
4271 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
4272 * to the value high for the pageset p.
4274 static void pageset_set_high(struct per_cpu_pageset
*p
,
4277 unsigned long batch
= max(1UL, high
/ 4);
4278 if ((high
/ 4) > (PAGE_SHIFT
* 8))
4279 batch
= PAGE_SHIFT
* 8;
4281 pageset_update(&p
->pcp
, high
, batch
);
4284 static void pageset_set_high_and_batch(struct zone
*zone
,
4285 struct per_cpu_pageset
*pcp
)
4287 if (percpu_pagelist_fraction
)
4288 pageset_set_high(pcp
,
4289 (zone
->managed_pages
/
4290 percpu_pagelist_fraction
));
4292 pageset_set_batch(pcp
, zone_batchsize(zone
));
4295 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
4297 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
4300 pageset_set_high_and_batch(zone
, pcp
);
4303 static void __meminit
setup_zone_pageset(struct zone
*zone
)
4306 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
4307 for_each_possible_cpu(cpu
)
4308 zone_pageset_init(zone
, cpu
);
4312 * Allocate per cpu pagesets and initialize them.
4313 * Before this call only boot pagesets were available.
4315 void __init
setup_per_cpu_pageset(void)
4319 for_each_populated_zone(zone
)
4320 setup_zone_pageset(zone
);
4323 static noinline __init_refok
4324 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
4330 * The per-page waitqueue mechanism uses hashed waitqueues
4333 zone
->wait_table_hash_nr_entries
=
4334 wait_table_hash_nr_entries(zone_size_pages
);
4335 zone
->wait_table_bits
=
4336 wait_table_bits(zone
->wait_table_hash_nr_entries
);
4337 alloc_size
= zone
->wait_table_hash_nr_entries
4338 * sizeof(wait_queue_head_t
);
4340 if (!slab_is_available()) {
4341 zone
->wait_table
= (wait_queue_head_t
*)
4342 memblock_virt_alloc_node_nopanic(
4343 alloc_size
, zone
->zone_pgdat
->node_id
);
4346 * This case means that a zone whose size was 0 gets new memory
4347 * via memory hot-add.
4348 * But it may be the case that a new node was hot-added. In
4349 * this case vmalloc() will not be able to use this new node's
4350 * memory - this wait_table must be initialized to use this new
4351 * node itself as well.
4352 * To use this new node's memory, further consideration will be
4355 zone
->wait_table
= vmalloc(alloc_size
);
4357 if (!zone
->wait_table
)
4360 for (i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
4361 init_waitqueue_head(zone
->wait_table
+ i
);
4366 static __meminit
void zone_pcp_init(struct zone
*zone
)
4369 * per cpu subsystem is not up at this point. The following code
4370 * relies on the ability of the linker to provide the
4371 * offset of a (static) per cpu variable into the per cpu area.
4373 zone
->pageset
= &boot_pageset
;
4375 if (populated_zone(zone
))
4376 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
4377 zone
->name
, zone
->present_pages
,
4378 zone_batchsize(zone
));
4381 int __meminit
init_currently_empty_zone(struct zone
*zone
,
4382 unsigned long zone_start_pfn
,
4384 enum memmap_context context
)
4386 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
4388 ret
= zone_wait_table_init(zone
, size
);
4391 pgdat
->nr_zones
= zone_idx(zone
) + 1;
4393 zone
->zone_start_pfn
= zone_start_pfn
;
4395 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
4396 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4398 (unsigned long)zone_idx(zone
),
4399 zone_start_pfn
, (zone_start_pfn
+ size
));
4401 zone_init_free_lists(zone
);
4406 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4407 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4409 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4411 int __meminit
__early_pfn_to_nid(unsigned long pfn
)
4413 unsigned long start_pfn
, end_pfn
;
4416 * NOTE: The following SMP-unsafe globals are only used early in boot
4417 * when the kernel is running single-threaded.
4419 static unsigned long __meminitdata last_start_pfn
, last_end_pfn
;
4420 static int __meminitdata last_nid
;
4422 if (last_start_pfn
<= pfn
&& pfn
< last_end_pfn
)
4425 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
4427 last_start_pfn
= start_pfn
;
4428 last_end_pfn
= end_pfn
;
4434 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
4436 int __meminit
early_pfn_to_nid(unsigned long pfn
)
4440 nid
= __early_pfn_to_nid(pfn
);
4443 /* just returns 0 */
4447 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
4448 bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
4452 nid
= __early_pfn_to_nid(pfn
);
4453 if (nid
>= 0 && nid
!= node
)
4460 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
4461 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
4462 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
4464 * If an architecture guarantees that all ranges registered contain no holes
4465 * and may be freed, this this function may be used instead of calling
4466 * memblock_free_early_nid() manually.
4468 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
4470 unsigned long start_pfn
, end_pfn
;
4473 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
4474 start_pfn
= min(start_pfn
, max_low_pfn
);
4475 end_pfn
= min(end_pfn
, max_low_pfn
);
4477 if (start_pfn
< end_pfn
)
4478 memblock_free_early_nid(PFN_PHYS(start_pfn
),
4479 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
4485 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4486 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4488 * If an architecture guarantees that all ranges registered contain no holes and may
4489 * be freed, this function may be used instead of calling memory_present() manually.
4491 void __init
sparse_memory_present_with_active_regions(int nid
)
4493 unsigned long start_pfn
, end_pfn
;
4496 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
4497 memory_present(this_nid
, start_pfn
, end_pfn
);
4501 * get_pfn_range_for_nid - Return the start and end page frames for a node
4502 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4503 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
4504 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
4506 * It returns the start and end page frame of a node based on information
4507 * provided by memblock_set_node(). If called for a node
4508 * with no available memory, a warning is printed and the start and end
4511 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
4512 unsigned long *start_pfn
, unsigned long *end_pfn
)
4514 unsigned long this_start_pfn
, this_end_pfn
;
4520 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
4521 *start_pfn
= min(*start_pfn
, this_start_pfn
);
4522 *end_pfn
= max(*end_pfn
, this_end_pfn
);
4525 if (*start_pfn
== -1UL)
4530 * This finds a zone that can be used for ZONE_MOVABLE pages. The
4531 * assumption is made that zones within a node are ordered in monotonic
4532 * increasing memory addresses so that the "highest" populated zone is used
4534 static void __init
find_usable_zone_for_movable(void)
4537 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
4538 if (zone_index
== ZONE_MOVABLE
)
4541 if (arch_zone_highest_possible_pfn
[zone_index
] >
4542 arch_zone_lowest_possible_pfn
[zone_index
])
4546 VM_BUG_ON(zone_index
== -1);
4547 movable_zone
= zone_index
;
4551 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4552 * because it is sized independent of architecture. Unlike the other zones,
4553 * the starting point for ZONE_MOVABLE is not fixed. It may be different
4554 * in each node depending on the size of each node and how evenly kernelcore
4555 * is distributed. This helper function adjusts the zone ranges
4556 * provided by the architecture for a given node by using the end of the
4557 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4558 * zones within a node are in order of monotonic increases memory addresses
4560 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
4561 unsigned long zone_type
,
4562 unsigned long node_start_pfn
,
4563 unsigned long node_end_pfn
,
4564 unsigned long *zone_start_pfn
,
4565 unsigned long *zone_end_pfn
)
4567 /* Only adjust if ZONE_MOVABLE is on this node */
4568 if (zone_movable_pfn
[nid
]) {
4569 /* Size ZONE_MOVABLE */
4570 if (zone_type
== ZONE_MOVABLE
) {
4571 *zone_start_pfn
= zone_movable_pfn
[nid
];
4572 *zone_end_pfn
= min(node_end_pfn
,
4573 arch_zone_highest_possible_pfn
[movable_zone
]);
4575 /* Adjust for ZONE_MOVABLE starting within this range */
4576 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
4577 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
4578 *zone_end_pfn
= zone_movable_pfn
[nid
];
4580 /* Check if this whole range is within ZONE_MOVABLE */
4581 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
4582 *zone_start_pfn
= *zone_end_pfn
;
4587 * Return the number of pages a zone spans in a node, including holes
4588 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4590 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4591 unsigned long zone_type
,
4592 unsigned long node_start_pfn
,
4593 unsigned long node_end_pfn
,
4594 unsigned long *ignored
)
4596 unsigned long zone_start_pfn
, zone_end_pfn
;
4598 /* Get the start and end of the zone */
4599 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
4600 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
4601 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4602 node_start_pfn
, node_end_pfn
,
4603 &zone_start_pfn
, &zone_end_pfn
);
4605 /* Check that this node has pages within the zone's required range */
4606 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
4609 /* Move the zone boundaries inside the node if necessary */
4610 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
4611 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
4613 /* Return the spanned pages */
4614 return zone_end_pfn
- zone_start_pfn
;
4618 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4619 * then all holes in the requested range will be accounted for.
4621 unsigned long __meminit
__absent_pages_in_range(int nid
,
4622 unsigned long range_start_pfn
,
4623 unsigned long range_end_pfn
)
4625 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
4626 unsigned long start_pfn
, end_pfn
;
4629 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
4630 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
4631 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
4632 nr_absent
-= end_pfn
- start_pfn
;
4638 * absent_pages_in_range - Return number of page frames in holes within a range
4639 * @start_pfn: The start PFN to start searching for holes
4640 * @end_pfn: The end PFN to stop searching for holes
4642 * It returns the number of pages frames in memory holes within a range.
4644 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
4645 unsigned long end_pfn
)
4647 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
4650 /* Return the number of page frames in holes in a zone on a node */
4651 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4652 unsigned long zone_type
,
4653 unsigned long node_start_pfn
,
4654 unsigned long node_end_pfn
,
4655 unsigned long *ignored
)
4657 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
4658 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
4659 unsigned long zone_start_pfn
, zone_end_pfn
;
4661 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
4662 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
4664 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4665 node_start_pfn
, node_end_pfn
,
4666 &zone_start_pfn
, &zone_end_pfn
);
4667 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
4670 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4671 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4672 unsigned long zone_type
,
4673 unsigned long node_start_pfn
,
4674 unsigned long node_end_pfn
,
4675 unsigned long *zones_size
)
4677 return zones_size
[zone_type
];
4680 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4681 unsigned long zone_type
,
4682 unsigned long node_start_pfn
,
4683 unsigned long node_end_pfn
,
4684 unsigned long *zholes_size
)
4689 return zholes_size
[zone_type
];
4692 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4694 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
4695 unsigned long node_start_pfn
,
4696 unsigned long node_end_pfn
,
4697 unsigned long *zones_size
,
4698 unsigned long *zholes_size
)
4700 unsigned long realtotalpages
, totalpages
= 0;
4703 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4704 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
4708 pgdat
->node_spanned_pages
= totalpages
;
4710 realtotalpages
= totalpages
;
4711 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4713 zone_absent_pages_in_node(pgdat
->node_id
, i
,
4714 node_start_pfn
, node_end_pfn
,
4716 pgdat
->node_present_pages
= realtotalpages
;
4717 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
4721 #ifndef CONFIG_SPARSEMEM
4723 * Calculate the size of the zone->blockflags rounded to an unsigned long
4724 * Start by making sure zonesize is a multiple of pageblock_order by rounding
4725 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4726 * round what is now in bits to nearest long in bits, then return it in
4729 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
4731 unsigned long usemapsize
;
4733 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
4734 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
4735 usemapsize
= usemapsize
>> pageblock_order
;
4736 usemapsize
*= NR_PAGEBLOCK_BITS
;
4737 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
4739 return usemapsize
/ 8;
4742 static void __init
setup_usemap(struct pglist_data
*pgdat
,
4744 unsigned long zone_start_pfn
,
4745 unsigned long zonesize
)
4747 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
4748 zone
->pageblock_flags
= NULL
;
4750 zone
->pageblock_flags
=
4751 memblock_virt_alloc_node_nopanic(usemapsize
,
4755 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
4756 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
4757 #endif /* CONFIG_SPARSEMEM */
4759 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4761 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4762 void __paginginit
set_pageblock_order(void)
4766 /* Check that pageblock_nr_pages has not already been setup */
4767 if (pageblock_order
)
4770 if (HPAGE_SHIFT
> PAGE_SHIFT
)
4771 order
= HUGETLB_PAGE_ORDER
;
4773 order
= MAX_ORDER
- 1;
4776 * Assume the largest contiguous order of interest is a huge page.
4777 * This value may be variable depending on boot parameters on IA64 and
4780 pageblock_order
= order
;
4782 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4785 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4786 * is unused as pageblock_order is set at compile-time. See
4787 * include/linux/pageblock-flags.h for the values of pageblock_order based on
4790 void __paginginit
set_pageblock_order(void)
4794 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4796 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
4797 unsigned long present_pages
)
4799 unsigned long pages
= spanned_pages
;
4802 * Provide a more accurate estimation if there are holes within
4803 * the zone and SPARSEMEM is in use. If there are holes within the
4804 * zone, each populated memory region may cost us one or two extra
4805 * memmap pages due to alignment because memmap pages for each
4806 * populated regions may not naturally algined on page boundary.
4807 * So the (present_pages >> 4) heuristic is a tradeoff for that.
4809 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
4810 IS_ENABLED(CONFIG_SPARSEMEM
))
4811 pages
= present_pages
;
4813 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
4817 * Set up the zone data structures:
4818 * - mark all pages reserved
4819 * - mark all memory queues empty
4820 * - clear the memory bitmaps
4822 * NOTE: pgdat should get zeroed by caller.
4824 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
,
4825 unsigned long node_start_pfn
, unsigned long node_end_pfn
,
4826 unsigned long *zones_size
, unsigned long *zholes_size
)
4829 int nid
= pgdat
->node_id
;
4830 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
4833 pgdat_resize_init(pgdat
);
4834 #ifdef CONFIG_NUMA_BALANCING
4835 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
4836 pgdat
->numabalancing_migrate_nr_pages
= 0;
4837 pgdat
->numabalancing_migrate_next_window
= jiffies
;
4839 init_waitqueue_head(&pgdat
->kswapd_wait
);
4840 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
4841 pgdat_page_cgroup_init(pgdat
);
4843 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4844 struct zone
*zone
= pgdat
->node_zones
+ j
;
4845 unsigned long size
, realsize
, freesize
, memmap_pages
;
4847 size
= zone_spanned_pages_in_node(nid
, j
, node_start_pfn
,
4848 node_end_pfn
, zones_size
);
4849 realsize
= freesize
= size
- zone_absent_pages_in_node(nid
, j
,
4855 * Adjust freesize so that it accounts for how much memory
4856 * is used by this zone for memmap. This affects the watermark
4857 * and per-cpu initialisations
4859 memmap_pages
= calc_memmap_size(size
, realsize
);
4860 if (freesize
>= memmap_pages
) {
4861 freesize
-= memmap_pages
;
4864 " %s zone: %lu pages used for memmap\n",
4865 zone_names
[j
], memmap_pages
);
4868 " %s zone: %lu pages exceeds freesize %lu\n",
4869 zone_names
[j
], memmap_pages
, freesize
);
4871 /* Account for reserved pages */
4872 if (j
== 0 && freesize
> dma_reserve
) {
4873 freesize
-= dma_reserve
;
4874 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
4875 zone_names
[0], dma_reserve
);
4878 if (!is_highmem_idx(j
))
4879 nr_kernel_pages
+= freesize
;
4880 /* Charge for highmem memmap if there are enough kernel pages */
4881 else if (nr_kernel_pages
> memmap_pages
* 2)
4882 nr_kernel_pages
-= memmap_pages
;
4883 nr_all_pages
+= freesize
;
4885 zone
->spanned_pages
= size
;
4886 zone
->present_pages
= realsize
;
4888 * Set an approximate value for lowmem here, it will be adjusted
4889 * when the bootmem allocator frees pages into the buddy system.
4890 * And all highmem pages will be managed by the buddy system.
4892 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
4895 zone
->min_unmapped_pages
= (freesize
*sysctl_min_unmapped_ratio
)
4897 zone
->min_slab_pages
= (freesize
* sysctl_min_slab_ratio
) / 100;
4899 zone
->name
= zone_names
[j
];
4900 spin_lock_init(&zone
->lock
);
4901 spin_lock_init(&zone
->lru_lock
);
4902 zone_seqlock_init(zone
);
4903 zone
->zone_pgdat
= pgdat
;
4904 zone_pcp_init(zone
);
4906 /* For bootup, initialized properly in watermark setup */
4907 mod_zone_page_state(zone
, NR_ALLOC_BATCH
, zone
->managed_pages
);
4909 lruvec_init(&zone
->lruvec
);
4913 set_pageblock_order();
4914 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
4915 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
4916 size
, MEMMAP_EARLY
);
4918 memmap_init(size
, nid
, j
, zone_start_pfn
);
4919 zone_start_pfn
+= size
;
4923 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
4925 /* Skip empty nodes */
4926 if (!pgdat
->node_spanned_pages
)
4929 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4930 /* ia64 gets its own node_mem_map, before this, without bootmem */
4931 if (!pgdat
->node_mem_map
) {
4932 unsigned long size
, start
, end
;
4936 * The zone's endpoints aren't required to be MAX_ORDER
4937 * aligned but the node_mem_map endpoints must be in order
4938 * for the buddy allocator to function correctly.
4940 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
4941 end
= pgdat_end_pfn(pgdat
);
4942 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
4943 size
= (end
- start
) * sizeof(struct page
);
4944 map
= alloc_remap(pgdat
->node_id
, size
);
4946 map
= memblock_virt_alloc_node_nopanic(size
,
4948 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
4950 #ifndef CONFIG_NEED_MULTIPLE_NODES
4952 * With no DISCONTIG, the global mem_map is just set as node 0's
4954 if (pgdat
== NODE_DATA(0)) {
4955 mem_map
= NODE_DATA(0)->node_mem_map
;
4956 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4957 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
4958 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
4959 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4962 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
4965 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
4966 unsigned long node_start_pfn
, unsigned long *zholes_size
)
4968 pg_data_t
*pgdat
= NODE_DATA(nid
);
4969 unsigned long start_pfn
= 0;
4970 unsigned long end_pfn
= 0;
4972 /* pg_data_t should be reset to zero when it's allocated */
4973 WARN_ON(pgdat
->nr_zones
|| pgdat
->classzone_idx
);
4975 pgdat
->node_id
= nid
;
4976 pgdat
->node_start_pfn
= node_start_pfn
;
4977 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4978 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
4980 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
4981 zones_size
, zholes_size
);
4983 alloc_node_mem_map(pgdat
);
4984 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4985 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
4986 nid
, (unsigned long)pgdat
,
4987 (unsigned long)pgdat
->node_mem_map
);
4990 free_area_init_core(pgdat
, start_pfn
, end_pfn
,
4991 zones_size
, zholes_size
);
4994 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4996 #if MAX_NUMNODES > 1
4998 * Figure out the number of possible node ids.
5000 void __init
setup_nr_node_ids(void)
5003 unsigned int highest
= 0;
5005 for_each_node_mask(node
, node_possible_map
)
5007 nr_node_ids
= highest
+ 1;
5012 * node_map_pfn_alignment - determine the maximum internode alignment
5014 * This function should be called after node map is populated and sorted.
5015 * It calculates the maximum power of two alignment which can distinguish
5018 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5019 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5020 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5021 * shifted, 1GiB is enough and this function will indicate so.
5023 * This is used to test whether pfn -> nid mapping of the chosen memory
5024 * model has fine enough granularity to avoid incorrect mapping for the
5025 * populated node map.
5027 * Returns the determined alignment in pfn's. 0 if there is no alignment
5028 * requirement (single node).
5030 unsigned long __init
node_map_pfn_alignment(void)
5032 unsigned long accl_mask
= 0, last_end
= 0;
5033 unsigned long start
, end
, mask
;
5037 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
5038 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
5045 * Start with a mask granular enough to pin-point to the
5046 * start pfn and tick off bits one-by-one until it becomes
5047 * too coarse to separate the current node from the last.
5049 mask
= ~((1 << __ffs(start
)) - 1);
5050 while (mask
&& last_end
<= (start
& (mask
<< 1)))
5053 /* accumulate all internode masks */
5057 /* convert mask to number of pages */
5058 return ~accl_mask
+ 1;
5061 /* Find the lowest pfn for a node */
5062 static unsigned long __init
find_min_pfn_for_node(int nid
)
5064 unsigned long min_pfn
= ULONG_MAX
;
5065 unsigned long start_pfn
;
5068 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
5069 min_pfn
= min(min_pfn
, start_pfn
);
5071 if (min_pfn
== ULONG_MAX
) {
5073 "Could not find start_pfn for node %d\n", nid
);
5081 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5083 * It returns the minimum PFN based on information provided via
5084 * memblock_set_node().
5086 unsigned long __init
find_min_pfn_with_active_regions(void)
5088 return find_min_pfn_for_node(MAX_NUMNODES
);
5092 * early_calculate_totalpages()
5093 * Sum pages in active regions for movable zone.
5094 * Populate N_MEMORY for calculating usable_nodes.
5096 static unsigned long __init
early_calculate_totalpages(void)
5098 unsigned long totalpages
= 0;
5099 unsigned long start_pfn
, end_pfn
;
5102 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
5103 unsigned long pages
= end_pfn
- start_pfn
;
5105 totalpages
+= pages
;
5107 node_set_state(nid
, N_MEMORY
);
5113 * Find the PFN the Movable zone begins in each node. Kernel memory
5114 * is spread evenly between nodes as long as the nodes have enough
5115 * memory. When they don't, some nodes will have more kernelcore than
5118 static void __init
find_zone_movable_pfns_for_nodes(void)
5121 unsigned long usable_startpfn
;
5122 unsigned long kernelcore_node
, kernelcore_remaining
;
5123 /* save the state before borrow the nodemask */
5124 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
5125 unsigned long totalpages
= early_calculate_totalpages();
5126 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
5127 struct memblock_region
*r
;
5129 /* Need to find movable_zone earlier when movable_node is specified. */
5130 find_usable_zone_for_movable();
5133 * If movable_node is specified, ignore kernelcore and movablecore
5136 if (movable_node_is_enabled()) {
5137 for_each_memblock(memory
, r
) {
5138 if (!memblock_is_hotpluggable(r
))
5143 usable_startpfn
= PFN_DOWN(r
->base
);
5144 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
5145 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
5153 * If movablecore=nn[KMG] was specified, calculate what size of
5154 * kernelcore that corresponds so that memory usable for
5155 * any allocation type is evenly spread. If both kernelcore
5156 * and movablecore are specified, then the value of kernelcore
5157 * will be used for required_kernelcore if it's greater than
5158 * what movablecore would have allowed.
5160 if (required_movablecore
) {
5161 unsigned long corepages
;
5164 * Round-up so that ZONE_MOVABLE is at least as large as what
5165 * was requested by the user
5167 required_movablecore
=
5168 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
5169 corepages
= totalpages
- required_movablecore
;
5171 required_kernelcore
= max(required_kernelcore
, corepages
);
5174 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
5175 if (!required_kernelcore
)
5178 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
5179 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
5182 /* Spread kernelcore memory as evenly as possible throughout nodes */
5183 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5184 for_each_node_state(nid
, N_MEMORY
) {
5185 unsigned long start_pfn
, end_pfn
;
5188 * Recalculate kernelcore_node if the division per node
5189 * now exceeds what is necessary to satisfy the requested
5190 * amount of memory for the kernel
5192 if (required_kernelcore
< kernelcore_node
)
5193 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5196 * As the map is walked, we track how much memory is usable
5197 * by the kernel using kernelcore_remaining. When it is
5198 * 0, the rest of the node is usable by ZONE_MOVABLE
5200 kernelcore_remaining
= kernelcore_node
;
5202 /* Go through each range of PFNs within this node */
5203 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5204 unsigned long size_pages
;
5206 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
5207 if (start_pfn
>= end_pfn
)
5210 /* Account for what is only usable for kernelcore */
5211 if (start_pfn
< usable_startpfn
) {
5212 unsigned long kernel_pages
;
5213 kernel_pages
= min(end_pfn
, usable_startpfn
)
5216 kernelcore_remaining
-= min(kernel_pages
,
5217 kernelcore_remaining
);
5218 required_kernelcore
-= min(kernel_pages
,
5219 required_kernelcore
);
5221 /* Continue if range is now fully accounted */
5222 if (end_pfn
<= usable_startpfn
) {
5225 * Push zone_movable_pfn to the end so
5226 * that if we have to rebalance
5227 * kernelcore across nodes, we will
5228 * not double account here
5230 zone_movable_pfn
[nid
] = end_pfn
;
5233 start_pfn
= usable_startpfn
;
5237 * The usable PFN range for ZONE_MOVABLE is from
5238 * start_pfn->end_pfn. Calculate size_pages as the
5239 * number of pages used as kernelcore
5241 size_pages
= end_pfn
- start_pfn
;
5242 if (size_pages
> kernelcore_remaining
)
5243 size_pages
= kernelcore_remaining
;
5244 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
5247 * Some kernelcore has been met, update counts and
5248 * break if the kernelcore for this node has been
5251 required_kernelcore
-= min(required_kernelcore
,
5253 kernelcore_remaining
-= size_pages
;
5254 if (!kernelcore_remaining
)
5260 * If there is still required_kernelcore, we do another pass with one
5261 * less node in the count. This will push zone_movable_pfn[nid] further
5262 * along on the nodes that still have memory until kernelcore is
5266 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
5270 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5271 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
5272 zone_movable_pfn
[nid
] =
5273 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
5276 /* restore the node_state */
5277 node_states
[N_MEMORY
] = saved_node_state
;
5280 /* Any regular or high memory on that node ? */
5281 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
5283 enum zone_type zone_type
;
5285 if (N_MEMORY
== N_NORMAL_MEMORY
)
5288 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
5289 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
5290 if (populated_zone(zone
)) {
5291 node_set_state(nid
, N_HIGH_MEMORY
);
5292 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
5293 zone_type
<= ZONE_NORMAL
)
5294 node_set_state(nid
, N_NORMAL_MEMORY
);
5301 * free_area_init_nodes - Initialise all pg_data_t and zone data
5302 * @max_zone_pfn: an array of max PFNs for each zone
5304 * This will call free_area_init_node() for each active node in the system.
5305 * Using the page ranges provided by memblock_set_node(), the size of each
5306 * zone in each node and their holes is calculated. If the maximum PFN
5307 * between two adjacent zones match, it is assumed that the zone is empty.
5308 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
5309 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
5310 * starts where the previous one ended. For example, ZONE_DMA32 starts
5311 * at arch_max_dma_pfn.
5313 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
5315 unsigned long start_pfn
, end_pfn
;
5318 /* Record where the zone boundaries are */
5319 memset(arch_zone_lowest_possible_pfn
, 0,
5320 sizeof(arch_zone_lowest_possible_pfn
));
5321 memset(arch_zone_highest_possible_pfn
, 0,
5322 sizeof(arch_zone_highest_possible_pfn
));
5323 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
5324 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
5325 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
5326 if (i
== ZONE_MOVABLE
)
5328 arch_zone_lowest_possible_pfn
[i
] =
5329 arch_zone_highest_possible_pfn
[i
-1];
5330 arch_zone_highest_possible_pfn
[i
] =
5331 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
5333 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
5334 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
5336 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
5337 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
5338 find_zone_movable_pfns_for_nodes();
5340 /* Print out the zone ranges */
5341 printk("Zone ranges:\n");
5342 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5343 if (i
== ZONE_MOVABLE
)
5345 printk(KERN_CONT
" %-8s ", zone_names
[i
]);
5346 if (arch_zone_lowest_possible_pfn
[i
] ==
5347 arch_zone_highest_possible_pfn
[i
])
5348 printk(KERN_CONT
"empty\n");
5350 printk(KERN_CONT
"[mem %0#10lx-%0#10lx]\n",
5351 arch_zone_lowest_possible_pfn
[i
] << PAGE_SHIFT
,
5352 (arch_zone_highest_possible_pfn
[i
]
5353 << PAGE_SHIFT
) - 1);
5356 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
5357 printk("Movable zone start for each node\n");
5358 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
5359 if (zone_movable_pfn
[i
])
5360 printk(" Node %d: %#010lx\n", i
,
5361 zone_movable_pfn
[i
] << PAGE_SHIFT
);
5364 /* Print out the early node map */
5365 printk("Early memory node ranges\n");
5366 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
5367 printk(" node %3d: [mem %#010lx-%#010lx]\n", nid
,
5368 start_pfn
<< PAGE_SHIFT
, (end_pfn
<< PAGE_SHIFT
) - 1);
5370 /* Initialise every node */
5371 mminit_verify_pageflags_layout();
5372 setup_nr_node_ids();
5373 for_each_online_node(nid
) {
5374 pg_data_t
*pgdat
= NODE_DATA(nid
);
5375 free_area_init_node(nid
, NULL
,
5376 find_min_pfn_for_node(nid
), NULL
);
5378 /* Any memory on that node */
5379 if (pgdat
->node_present_pages
)
5380 node_set_state(nid
, N_MEMORY
);
5381 check_for_memory(pgdat
, nid
);
5385 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
5387 unsigned long long coremem
;
5391 coremem
= memparse(p
, &p
);
5392 *core
= coremem
>> PAGE_SHIFT
;
5394 /* Paranoid check that UL is enough for the coremem value */
5395 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
5401 * kernelcore=size sets the amount of memory for use for allocations that
5402 * cannot be reclaimed or migrated.
5404 static int __init
cmdline_parse_kernelcore(char *p
)
5406 return cmdline_parse_core(p
, &required_kernelcore
);
5410 * movablecore=size sets the amount of memory for use for allocations that
5411 * can be reclaimed or migrated.
5413 static int __init
cmdline_parse_movablecore(char *p
)
5415 return cmdline_parse_core(p
, &required_movablecore
);
5418 early_param("kernelcore", cmdline_parse_kernelcore
);
5419 early_param("movablecore", cmdline_parse_movablecore
);
5421 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5423 void adjust_managed_page_count(struct page
*page
, long count
)
5425 spin_lock(&managed_page_count_lock
);
5426 page_zone(page
)->managed_pages
+= count
;
5427 totalram_pages
+= count
;
5428 #ifdef CONFIG_HIGHMEM
5429 if (PageHighMem(page
))
5430 totalhigh_pages
+= count
;
5432 spin_unlock(&managed_page_count_lock
);
5434 EXPORT_SYMBOL(adjust_managed_page_count
);
5436 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
5439 unsigned long pages
= 0;
5441 start
= (void *)PAGE_ALIGN((unsigned long)start
);
5442 end
= (void *)((unsigned long)end
& PAGE_MASK
);
5443 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
5444 if ((unsigned int)poison
<= 0xFF)
5445 memset(pos
, poison
, PAGE_SIZE
);
5446 free_reserved_page(virt_to_page(pos
));
5450 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
5451 s
, pages
<< (PAGE_SHIFT
- 10), start
, end
);
5455 EXPORT_SYMBOL(free_reserved_area
);
5457 #ifdef CONFIG_HIGHMEM
5458 void free_highmem_page(struct page
*page
)
5460 __free_reserved_page(page
);
5462 page_zone(page
)->managed_pages
++;
5468 void __init
mem_init_print_info(const char *str
)
5470 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
5471 unsigned long init_code_size
, init_data_size
;
5473 physpages
= get_num_physpages();
5474 codesize
= _etext
- _stext
;
5475 datasize
= _edata
- _sdata
;
5476 rosize
= __end_rodata
- __start_rodata
;
5477 bss_size
= __bss_stop
- __bss_start
;
5478 init_data_size
= __init_end
- __init_begin
;
5479 init_code_size
= _einittext
- _sinittext
;
5482 * Detect special cases and adjust section sizes accordingly:
5483 * 1) .init.* may be embedded into .data sections
5484 * 2) .init.text.* may be out of [__init_begin, __init_end],
5485 * please refer to arch/tile/kernel/vmlinux.lds.S.
5486 * 3) .rodata.* may be embedded into .text or .data sections.
5488 #define adj_init_size(start, end, size, pos, adj) \
5490 if (start <= pos && pos < end && size > adj) \
5494 adj_init_size(__init_begin
, __init_end
, init_data_size
,
5495 _sinittext
, init_code_size
);
5496 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
5497 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
5498 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
5499 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
5501 #undef adj_init_size
5503 printk("Memory: %luK/%luK available "
5504 "(%luK kernel code, %luK rwdata, %luK rodata, "
5505 "%luK init, %luK bss, %luK reserved"
5506 #ifdef CONFIG_HIGHMEM
5510 nr_free_pages() << (PAGE_SHIFT
-10), physpages
<< (PAGE_SHIFT
-10),
5511 codesize
>> 10, datasize
>> 10, rosize
>> 10,
5512 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
5513 (physpages
- totalram_pages
) << (PAGE_SHIFT
-10),
5514 #ifdef CONFIG_HIGHMEM
5515 totalhigh_pages
<< (PAGE_SHIFT
-10),
5517 str
? ", " : "", str
? str
: "");
5521 * set_dma_reserve - set the specified number of pages reserved in the first zone
5522 * @new_dma_reserve: The number of pages to mark reserved
5524 * The per-cpu batchsize and zone watermarks are determined by present_pages.
5525 * In the DMA zone, a significant percentage may be consumed by kernel image
5526 * and other unfreeable allocations which can skew the watermarks badly. This
5527 * function may optionally be used to account for unfreeable pages in the
5528 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
5529 * smaller per-cpu batchsize.
5531 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
5533 dma_reserve
= new_dma_reserve
;
5536 void __init
free_area_init(unsigned long *zones_size
)
5538 free_area_init_node(0, zones_size
,
5539 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
5542 static int page_alloc_cpu_notify(struct notifier_block
*self
,
5543 unsigned long action
, void *hcpu
)
5545 int cpu
= (unsigned long)hcpu
;
5547 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
5548 lru_add_drain_cpu(cpu
);
5552 * Spill the event counters of the dead processor
5553 * into the current processors event counters.
5554 * This artificially elevates the count of the current
5557 vm_events_fold_cpu(cpu
);
5560 * Zero the differential counters of the dead processor
5561 * so that the vm statistics are consistent.
5563 * This is only okay since the processor is dead and cannot
5564 * race with what we are doing.
5566 cpu_vm_stats_fold(cpu
);
5571 void __init
page_alloc_init(void)
5573 hotcpu_notifier(page_alloc_cpu_notify
, 0);
5577 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
5578 * or min_free_kbytes changes.
5580 static void calculate_totalreserve_pages(void)
5582 struct pglist_data
*pgdat
;
5583 unsigned long reserve_pages
= 0;
5584 enum zone_type i
, j
;
5586 for_each_online_pgdat(pgdat
) {
5587 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5588 struct zone
*zone
= pgdat
->node_zones
+ i
;
5591 /* Find valid and maximum lowmem_reserve in the zone */
5592 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
5593 if (zone
->lowmem_reserve
[j
] > max
)
5594 max
= zone
->lowmem_reserve
[j
];
5597 /* we treat the high watermark as reserved pages. */
5598 max
+= high_wmark_pages(zone
);
5600 if (max
> zone
->managed_pages
)
5601 max
= zone
->managed_pages
;
5602 reserve_pages
+= max
;
5604 * Lowmem reserves are not available to
5605 * GFP_HIGHUSER page cache allocations and
5606 * kswapd tries to balance zones to their high
5607 * watermark. As a result, neither should be
5608 * regarded as dirtyable memory, to prevent a
5609 * situation where reclaim has to clean pages
5610 * in order to balance the zones.
5612 zone
->dirty_balance_reserve
= max
;
5615 dirty_balance_reserve
= reserve_pages
;
5616 totalreserve_pages
= reserve_pages
;
5620 * setup_per_zone_lowmem_reserve - called whenever
5621 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
5622 * has a correct pages reserved value, so an adequate number of
5623 * pages are left in the zone after a successful __alloc_pages().
5625 static void setup_per_zone_lowmem_reserve(void)
5627 struct pglist_data
*pgdat
;
5628 enum zone_type j
, idx
;
5630 for_each_online_pgdat(pgdat
) {
5631 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5632 struct zone
*zone
= pgdat
->node_zones
+ j
;
5633 unsigned long managed_pages
= zone
->managed_pages
;
5635 zone
->lowmem_reserve
[j
] = 0;
5639 struct zone
*lower_zone
;
5643 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
5644 sysctl_lowmem_reserve_ratio
[idx
] = 1;
5646 lower_zone
= pgdat
->node_zones
+ idx
;
5647 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
5648 sysctl_lowmem_reserve_ratio
[idx
];
5649 managed_pages
+= lower_zone
->managed_pages
;
5654 /* update totalreserve_pages */
5655 calculate_totalreserve_pages();
5658 static void __setup_per_zone_wmarks(void)
5660 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
5661 unsigned long lowmem_pages
= 0;
5663 unsigned long flags
;
5665 /* Calculate total number of !ZONE_HIGHMEM pages */
5666 for_each_zone(zone
) {
5667 if (!is_highmem(zone
))
5668 lowmem_pages
+= zone
->managed_pages
;
5671 for_each_zone(zone
) {
5674 spin_lock_irqsave(&zone
->lock
, flags
);
5675 tmp
= (u64
)pages_min
* zone
->managed_pages
;
5676 do_div(tmp
, lowmem_pages
);
5677 if (is_highmem(zone
)) {
5679 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
5680 * need highmem pages, so cap pages_min to a small
5683 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
5684 * deltas controls asynch page reclaim, and so should
5685 * not be capped for highmem.
5687 unsigned long min_pages
;
5689 min_pages
= zone
->managed_pages
/ 1024;
5690 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
5691 zone
->watermark
[WMARK_MIN
] = min_pages
;
5694 * If it's a lowmem zone, reserve a number of pages
5695 * proportionate to the zone's size.
5697 zone
->watermark
[WMARK_MIN
] = tmp
;
5700 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + (tmp
>> 2);
5701 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + (tmp
>> 1);
5703 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
5704 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
5705 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
5707 setup_zone_migrate_reserve(zone
);
5708 spin_unlock_irqrestore(&zone
->lock
, flags
);
5711 /* update totalreserve_pages */
5712 calculate_totalreserve_pages();
5716 * setup_per_zone_wmarks - called when min_free_kbytes changes
5717 * or when memory is hot-{added|removed}
5719 * Ensures that the watermark[min,low,high] values for each zone are set
5720 * correctly with respect to min_free_kbytes.
5722 void setup_per_zone_wmarks(void)
5724 mutex_lock(&zonelists_mutex
);
5725 __setup_per_zone_wmarks();
5726 mutex_unlock(&zonelists_mutex
);
5730 * The inactive anon list should be small enough that the VM never has to
5731 * do too much work, but large enough that each inactive page has a chance
5732 * to be referenced again before it is swapped out.
5734 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
5735 * INACTIVE_ANON pages on this zone's LRU, maintained by the
5736 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
5737 * the anonymous pages are kept on the inactive list.
5740 * memory ratio inactive anon
5741 * -------------------------------------
5750 static void __meminit
calculate_zone_inactive_ratio(struct zone
*zone
)
5752 unsigned int gb
, ratio
;
5754 /* Zone size in gigabytes */
5755 gb
= zone
->managed_pages
>> (30 - PAGE_SHIFT
);
5757 ratio
= int_sqrt(10 * gb
);
5761 zone
->inactive_ratio
= ratio
;
5764 static void __meminit
setup_per_zone_inactive_ratio(void)
5769 calculate_zone_inactive_ratio(zone
);
5773 * Initialise min_free_kbytes.
5775 * For small machines we want it small (128k min). For large machines
5776 * we want it large (64MB max). But it is not linear, because network
5777 * bandwidth does not increase linearly with machine size. We use
5779 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
5780 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
5796 int __meminit
init_per_zone_wmark_min(void)
5798 unsigned long lowmem_kbytes
;
5799 int new_min_free_kbytes
;
5801 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
5802 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
5804 if (new_min_free_kbytes
> user_min_free_kbytes
) {
5805 min_free_kbytes
= new_min_free_kbytes
;
5806 if (min_free_kbytes
< 128)
5807 min_free_kbytes
= 128;
5808 if (min_free_kbytes
> 65536)
5809 min_free_kbytes
= 65536;
5811 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
5812 new_min_free_kbytes
, user_min_free_kbytes
);
5814 setup_per_zone_wmarks();
5815 refresh_zone_stat_thresholds();
5816 setup_per_zone_lowmem_reserve();
5817 setup_per_zone_inactive_ratio();
5820 module_init(init_per_zone_wmark_min
)
5823 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5824 * that we can call two helper functions whenever min_free_kbytes
5827 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
5828 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5832 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5837 user_min_free_kbytes
= min_free_kbytes
;
5838 setup_per_zone_wmarks();
5844 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
5845 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5850 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5855 zone
->min_unmapped_pages
= (zone
->managed_pages
*
5856 sysctl_min_unmapped_ratio
) / 100;
5860 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
5861 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5866 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5871 zone
->min_slab_pages
= (zone
->managed_pages
*
5872 sysctl_min_slab_ratio
) / 100;
5878 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5879 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5880 * whenever sysctl_lowmem_reserve_ratio changes.
5882 * The reserve ratio obviously has absolutely no relation with the
5883 * minimum watermarks. The lowmem reserve ratio can only make sense
5884 * if in function of the boot time zone sizes.
5886 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
5887 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5889 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5890 setup_per_zone_lowmem_reserve();
5895 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5896 * cpu. It is the fraction of total pages in each zone that a hot per cpu
5897 * pagelist can have before it gets flushed back to buddy allocator.
5899 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
5900 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5903 int old_percpu_pagelist_fraction
;
5906 mutex_lock(&pcp_batch_high_lock
);
5907 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
5909 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5910 if (!write
|| ret
< 0)
5913 /* Sanity checking to avoid pcp imbalance */
5914 if (percpu_pagelist_fraction
&&
5915 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
5916 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
5922 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
5925 for_each_populated_zone(zone
) {
5928 for_each_possible_cpu(cpu
)
5929 pageset_set_high_and_batch(zone
,
5930 per_cpu_ptr(zone
->pageset
, cpu
));
5933 mutex_unlock(&pcp_batch_high_lock
);
5937 int hashdist
= HASHDIST_DEFAULT
;
5940 static int __init
set_hashdist(char *str
)
5944 hashdist
= simple_strtoul(str
, &str
, 0);
5947 __setup("hashdist=", set_hashdist
);
5951 * allocate a large system hash table from bootmem
5952 * - it is assumed that the hash table must contain an exact power-of-2
5953 * quantity of entries
5954 * - limit is the number of hash buckets, not the total allocation size
5956 void *__init
alloc_large_system_hash(const char *tablename
,
5957 unsigned long bucketsize
,
5958 unsigned long numentries
,
5961 unsigned int *_hash_shift
,
5962 unsigned int *_hash_mask
,
5963 unsigned long low_limit
,
5964 unsigned long high_limit
)
5966 unsigned long long max
= high_limit
;
5967 unsigned long log2qty
, size
;
5970 /* allow the kernel cmdline to have a say */
5972 /* round applicable memory size up to nearest megabyte */
5973 numentries
= nr_kernel_pages
;
5975 /* It isn't necessary when PAGE_SIZE >= 1MB */
5976 if (PAGE_SHIFT
< 20)
5977 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
5979 /* limit to 1 bucket per 2^scale bytes of low memory */
5980 if (scale
> PAGE_SHIFT
)
5981 numentries
>>= (scale
- PAGE_SHIFT
);
5983 numentries
<<= (PAGE_SHIFT
- scale
);
5985 /* Make sure we've got at least a 0-order allocation.. */
5986 if (unlikely(flags
& HASH_SMALL
)) {
5987 /* Makes no sense without HASH_EARLY */
5988 WARN_ON(!(flags
& HASH_EARLY
));
5989 if (!(numentries
>> *_hash_shift
)) {
5990 numentries
= 1UL << *_hash_shift
;
5991 BUG_ON(!numentries
);
5993 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
5994 numentries
= PAGE_SIZE
/ bucketsize
;
5996 numentries
= roundup_pow_of_two(numentries
);
5998 /* limit allocation size to 1/16 total memory by default */
6000 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
6001 do_div(max
, bucketsize
);
6003 max
= min(max
, 0x80000000ULL
);
6005 if (numentries
< low_limit
)
6006 numentries
= low_limit
;
6007 if (numentries
> max
)
6010 log2qty
= ilog2(numentries
);
6013 size
= bucketsize
<< log2qty
;
6014 if (flags
& HASH_EARLY
)
6015 table
= memblock_virt_alloc_nopanic(size
, 0);
6017 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
6020 * If bucketsize is not a power-of-two, we may free
6021 * some pages at the end of hash table which
6022 * alloc_pages_exact() automatically does
6024 if (get_order(size
) < MAX_ORDER
) {
6025 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
6026 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
6029 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
6032 panic("Failed to allocate %s hash table\n", tablename
);
6034 printk(KERN_INFO
"%s hash table entries: %ld (order: %d, %lu bytes)\n",
6037 ilog2(size
) - PAGE_SHIFT
,
6041 *_hash_shift
= log2qty
;
6043 *_hash_mask
= (1 << log2qty
) - 1;
6048 /* Return a pointer to the bitmap storing bits affecting a block of pages */
6049 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
6052 #ifdef CONFIG_SPARSEMEM
6053 return __pfn_to_section(pfn
)->pageblock_flags
;
6055 return zone
->pageblock_flags
;
6056 #endif /* CONFIG_SPARSEMEM */
6059 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
6061 #ifdef CONFIG_SPARSEMEM
6062 pfn
&= (PAGES_PER_SECTION
-1);
6063 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6065 pfn
= pfn
- round_down(zone
->zone_start_pfn
, pageblock_nr_pages
);
6066 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6067 #endif /* CONFIG_SPARSEMEM */
6071 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
6072 * @page: The page within the block of interest
6073 * @pfn: The target page frame number
6074 * @end_bitidx: The last bit of interest to retrieve
6075 * @mask: mask of bits that the caller is interested in
6077 * Return: pageblock_bits flags
6079 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
6080 unsigned long end_bitidx
,
6084 unsigned long *bitmap
;
6085 unsigned long bitidx
, word_bitidx
;
6088 zone
= page_zone(page
);
6089 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6090 bitidx
= pfn_to_bitidx(zone
, pfn
);
6091 word_bitidx
= bitidx
/ BITS_PER_LONG
;
6092 bitidx
&= (BITS_PER_LONG
-1);
6094 word
= bitmap
[word_bitidx
];
6095 bitidx
+= end_bitidx
;
6096 return (word
>> (BITS_PER_LONG
- bitidx
- 1)) & mask
;
6100 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
6101 * @page: The page within the block of interest
6102 * @flags: The flags to set
6103 * @pfn: The target page frame number
6104 * @end_bitidx: The last bit of interest
6105 * @mask: mask of bits that the caller is interested in
6107 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
6109 unsigned long end_bitidx
,
6113 unsigned long *bitmap
;
6114 unsigned long bitidx
, word_bitidx
;
6115 unsigned long old_word
, word
;
6117 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
6119 zone
= page_zone(page
);
6120 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6121 bitidx
= pfn_to_bitidx(zone
, pfn
);
6122 word_bitidx
= bitidx
/ BITS_PER_LONG
;
6123 bitidx
&= (BITS_PER_LONG
-1);
6125 VM_BUG_ON_PAGE(!zone_spans_pfn(zone
, pfn
), page
);
6127 bitidx
+= end_bitidx
;
6128 mask
<<= (BITS_PER_LONG
- bitidx
- 1);
6129 flags
<<= (BITS_PER_LONG
- bitidx
- 1);
6131 word
= ACCESS_ONCE(bitmap
[word_bitidx
]);
6133 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
6134 if (word
== old_word
)
6141 * This function checks whether pageblock includes unmovable pages or not.
6142 * If @count is not zero, it is okay to include less @count unmovable pages
6144 * PageLRU check without isolation or lru_lock could race so that
6145 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6146 * expect this function should be exact.
6148 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
6149 bool skip_hwpoisoned_pages
)
6151 unsigned long pfn
, iter
, found
;
6155 * For avoiding noise data, lru_add_drain_all() should be called
6156 * If ZONE_MOVABLE, the zone never contains unmovable pages
6158 if (zone_idx(zone
) == ZONE_MOVABLE
)
6160 mt
= get_pageblock_migratetype(page
);
6161 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
6164 pfn
= page_to_pfn(page
);
6165 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
6166 unsigned long check
= pfn
+ iter
;
6168 if (!pfn_valid_within(check
))
6171 page
= pfn_to_page(check
);
6174 * Hugepages are not in LRU lists, but they're movable.
6175 * We need not scan over tail pages bacause we don't
6176 * handle each tail page individually in migration.
6178 if (PageHuge(page
)) {
6179 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
6184 * We can't use page_count without pin a page
6185 * because another CPU can free compound page.
6186 * This check already skips compound tails of THP
6187 * because their page->_count is zero at all time.
6189 if (!atomic_read(&page
->_count
)) {
6190 if (PageBuddy(page
))
6191 iter
+= (1 << page_order(page
)) - 1;
6196 * The HWPoisoned page may be not in buddy system, and
6197 * page_count() is not 0.
6199 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
6205 * If there are RECLAIMABLE pages, we need to check it.
6206 * But now, memory offline itself doesn't call shrink_slab()
6207 * and it still to be fixed.
6210 * If the page is not RAM, page_count()should be 0.
6211 * we don't need more check. This is an _used_ not-movable page.
6213 * The problematic thing here is PG_reserved pages. PG_reserved
6214 * is set to both of a memory hole page and a _used_ kernel
6223 bool is_pageblock_removable_nolock(struct page
*page
)
6229 * We have to be careful here because we are iterating over memory
6230 * sections which are not zone aware so we might end up outside of
6231 * the zone but still within the section.
6232 * We have to take care about the node as well. If the node is offline
6233 * its NODE_DATA will be NULL - see page_zone.
6235 if (!node_online(page_to_nid(page
)))
6238 zone
= page_zone(page
);
6239 pfn
= page_to_pfn(page
);
6240 if (!zone_spans_pfn(zone
, pfn
))
6243 return !has_unmovable_pages(zone
, page
, 0, true);
6248 static unsigned long pfn_max_align_down(unsigned long pfn
)
6250 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6251 pageblock_nr_pages
) - 1);
6254 static unsigned long pfn_max_align_up(unsigned long pfn
)
6256 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6257 pageblock_nr_pages
));
6260 /* [start, end) must belong to a single zone. */
6261 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
6262 unsigned long start
, unsigned long end
)
6264 /* This function is based on compact_zone() from compaction.c. */
6265 unsigned long nr_reclaimed
;
6266 unsigned long pfn
= start
;
6267 unsigned int tries
= 0;
6272 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
6273 if (fatal_signal_pending(current
)) {
6278 if (list_empty(&cc
->migratepages
)) {
6279 cc
->nr_migratepages
= 0;
6280 pfn
= isolate_migratepages_range(cc
->zone
, cc
,
6287 } else if (++tries
== 5) {
6288 ret
= ret
< 0 ? ret
: -EBUSY
;
6292 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
6294 cc
->nr_migratepages
-= nr_reclaimed
;
6296 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
6297 NULL
, 0, cc
->mode
, MR_CMA
);
6300 putback_movable_pages(&cc
->migratepages
);
6307 * alloc_contig_range() -- tries to allocate given range of pages
6308 * @start: start PFN to allocate
6309 * @end: one-past-the-last PFN to allocate
6310 * @migratetype: migratetype of the underlaying pageblocks (either
6311 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
6312 * in range must have the same migratetype and it must
6313 * be either of the two.
6315 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
6316 * aligned, however it's the caller's responsibility to guarantee that
6317 * we are the only thread that changes migrate type of pageblocks the
6320 * The PFN range must belong to a single zone.
6322 * Returns zero on success or negative error code. On success all
6323 * pages which PFN is in [start, end) are allocated for the caller and
6324 * need to be freed with free_contig_range().
6326 int alloc_contig_range(unsigned long start
, unsigned long end
,
6327 unsigned migratetype
)
6329 unsigned long outer_start
, outer_end
;
6332 struct compact_control cc
= {
6333 .nr_migratepages
= 0,
6335 .zone
= page_zone(pfn_to_page(start
)),
6336 .mode
= MIGRATE_SYNC
,
6337 .ignore_skip_hint
= true,
6339 INIT_LIST_HEAD(&cc
.migratepages
);
6342 * What we do here is we mark all pageblocks in range as
6343 * MIGRATE_ISOLATE. Because pageblock and max order pages may
6344 * have different sizes, and due to the way page allocator
6345 * work, we align the range to biggest of the two pages so
6346 * that page allocator won't try to merge buddies from
6347 * different pageblocks and change MIGRATE_ISOLATE to some
6348 * other migration type.
6350 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
6351 * migrate the pages from an unaligned range (ie. pages that
6352 * we are interested in). This will put all the pages in
6353 * range back to page allocator as MIGRATE_ISOLATE.
6355 * When this is done, we take the pages in range from page
6356 * allocator removing them from the buddy system. This way
6357 * page allocator will never consider using them.
6359 * This lets us mark the pageblocks back as
6360 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
6361 * aligned range but not in the unaligned, original range are
6362 * put back to page allocator so that buddy can use them.
6365 ret
= start_isolate_page_range(pfn_max_align_down(start
),
6366 pfn_max_align_up(end
), migratetype
,
6371 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
6376 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
6377 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
6378 * more, all pages in [start, end) are free in page allocator.
6379 * What we are going to do is to allocate all pages from
6380 * [start, end) (that is remove them from page allocator).
6382 * The only problem is that pages at the beginning and at the
6383 * end of interesting range may be not aligned with pages that
6384 * page allocator holds, ie. they can be part of higher order
6385 * pages. Because of this, we reserve the bigger range and
6386 * once this is done free the pages we are not interested in.
6388 * We don't have to hold zone->lock here because the pages are
6389 * isolated thus they won't get removed from buddy.
6392 lru_add_drain_all();
6396 outer_start
= start
;
6397 while (!PageBuddy(pfn_to_page(outer_start
))) {
6398 if (++order
>= MAX_ORDER
) {
6402 outer_start
&= ~0UL << order
;
6405 /* Make sure the range is really isolated. */
6406 if (test_pages_isolated(outer_start
, end
, false)) {
6407 pr_warn("alloc_contig_range test_pages_isolated(%lx, %lx) failed\n",
6414 /* Grab isolated pages from freelists. */
6415 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
6421 /* Free head and tail (if any) */
6422 if (start
!= outer_start
)
6423 free_contig_range(outer_start
, start
- outer_start
);
6424 if (end
!= outer_end
)
6425 free_contig_range(end
, outer_end
- end
);
6428 undo_isolate_page_range(pfn_max_align_down(start
),
6429 pfn_max_align_up(end
), migratetype
);
6433 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
6435 unsigned int count
= 0;
6437 for (; nr_pages
--; pfn
++) {
6438 struct page
*page
= pfn_to_page(pfn
);
6440 count
+= page_count(page
) != 1;
6443 WARN(count
!= 0, "%d pages are still in use!\n", count
);
6447 #ifdef CONFIG_MEMORY_HOTPLUG
6449 * The zone indicated has a new number of managed_pages; batch sizes and percpu
6450 * page high values need to be recalulated.
6452 void __meminit
zone_pcp_update(struct zone
*zone
)
6455 mutex_lock(&pcp_batch_high_lock
);
6456 for_each_possible_cpu(cpu
)
6457 pageset_set_high_and_batch(zone
,
6458 per_cpu_ptr(zone
->pageset
, cpu
));
6459 mutex_unlock(&pcp_batch_high_lock
);
6463 void zone_pcp_reset(struct zone
*zone
)
6465 unsigned long flags
;
6467 struct per_cpu_pageset
*pset
;
6469 /* avoid races with drain_pages() */
6470 local_irq_save(flags
);
6471 if (zone
->pageset
!= &boot_pageset
) {
6472 for_each_online_cpu(cpu
) {
6473 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
6474 drain_zonestat(zone
, pset
);
6476 free_percpu(zone
->pageset
);
6477 zone
->pageset
= &boot_pageset
;
6479 local_irq_restore(flags
);
6482 #ifdef CONFIG_MEMORY_HOTREMOVE
6484 * All pages in the range must be isolated before calling this.
6487 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
6491 unsigned int order
, i
;
6493 unsigned long flags
;
6494 /* find the first valid pfn */
6495 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
6500 zone
= page_zone(pfn_to_page(pfn
));
6501 spin_lock_irqsave(&zone
->lock
, flags
);
6503 while (pfn
< end_pfn
) {
6504 if (!pfn_valid(pfn
)) {
6508 page
= pfn_to_page(pfn
);
6510 * The HWPoisoned page may be not in buddy system, and
6511 * page_count() is not 0.
6513 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
6515 SetPageReserved(page
);
6519 BUG_ON(page_count(page
));
6520 BUG_ON(!PageBuddy(page
));
6521 order
= page_order(page
);
6522 #ifdef CONFIG_DEBUG_VM
6523 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
6524 pfn
, 1 << order
, end_pfn
);
6526 list_del(&page
->lru
);
6527 rmv_page_order(page
);
6528 zone
->free_area
[order
].nr_free
--;
6529 for (i
= 0; i
< (1 << order
); i
++)
6530 SetPageReserved((page
+i
));
6531 pfn
+= (1 << order
);
6533 spin_unlock_irqrestore(&zone
->lock
, flags
);
6537 #ifdef CONFIG_MEMORY_FAILURE
6538 bool is_free_buddy_page(struct page
*page
)
6540 struct zone
*zone
= page_zone(page
);
6541 unsigned long pfn
= page_to_pfn(page
);
6542 unsigned long flags
;
6545 spin_lock_irqsave(&zone
->lock
, flags
);
6546 for (order
= 0; order
< MAX_ORDER
; order
++) {
6547 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
6549 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
6552 spin_unlock_irqrestore(&zone
->lock
, flags
);
6554 return order
< MAX_ORDER
;
6558 static const struct trace_print_flags pageflag_names
[] = {
6559 {1UL << PG_locked
, "locked" },
6560 {1UL << PG_error
, "error" },
6561 {1UL << PG_referenced
, "referenced" },
6562 {1UL << PG_uptodate
, "uptodate" },
6563 {1UL << PG_dirty
, "dirty" },
6564 {1UL << PG_lru
, "lru" },
6565 {1UL << PG_active
, "active" },
6566 {1UL << PG_slab
, "slab" },
6567 {1UL << PG_owner_priv_1
, "owner_priv_1" },
6568 {1UL << PG_arch_1
, "arch_1" },
6569 {1UL << PG_reserved
, "reserved" },
6570 {1UL << PG_private
, "private" },
6571 {1UL << PG_private_2
, "private_2" },
6572 {1UL << PG_writeback
, "writeback" },
6573 #ifdef CONFIG_PAGEFLAGS_EXTENDED
6574 {1UL << PG_head
, "head" },
6575 {1UL << PG_tail
, "tail" },
6577 {1UL << PG_compound
, "compound" },
6579 {1UL << PG_swapcache
, "swapcache" },
6580 {1UL << PG_mappedtodisk
, "mappedtodisk" },
6581 {1UL << PG_reclaim
, "reclaim" },
6582 {1UL << PG_swapbacked
, "swapbacked" },
6583 {1UL << PG_unevictable
, "unevictable" },
6585 {1UL << PG_mlocked
, "mlocked" },
6587 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
6588 {1UL << PG_uncached
, "uncached" },
6590 #ifdef CONFIG_MEMORY_FAILURE
6591 {1UL << PG_hwpoison
, "hwpoison" },
6593 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6594 {1UL << PG_compound_lock
, "compound_lock" },
6598 static void dump_page_flags(unsigned long flags
)
6600 const char *delim
= "";
6604 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names
) != __NR_PAGEFLAGS
);
6606 printk(KERN_ALERT
"page flags: %#lx(", flags
);
6608 /* remove zone id */
6609 flags
&= (1UL << NR_PAGEFLAGS
) - 1;
6611 for (i
= 0; i
< ARRAY_SIZE(pageflag_names
) && flags
; i
++) {
6613 mask
= pageflag_names
[i
].mask
;
6614 if ((flags
& mask
) != mask
)
6618 printk("%s%s", delim
, pageflag_names
[i
].name
);
6622 /* check for left over flags */
6624 printk("%s%#lx", delim
, flags
);
6629 void dump_page_badflags(struct page
*page
, const char *reason
,
6630 unsigned long badflags
)
6633 "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
6634 page
, atomic_read(&page
->_count
), page_mapcount(page
),
6635 page
->mapping
, page
->index
);
6636 dump_page_flags(page
->flags
);
6638 pr_alert("page dumped because: %s\n", reason
);
6639 if (page
->flags
& badflags
) {
6640 pr_alert("bad because of flags:\n");
6641 dump_page_flags(page
->flags
& badflags
);
6643 mem_cgroup_print_bad_page(page
);
6646 void dump_page(struct page
*page
, const char *reason
)
6648 dump_page_badflags(page
, reason
, 0);
6650 EXPORT_SYMBOL(dump_page
);