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
);
73 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
74 DEFINE_PER_CPU(int, numa_node
);
75 EXPORT_PER_CPU_SYMBOL(numa_node
);
78 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
80 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
81 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
82 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
83 * defined in <linux/topology.h>.
85 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
86 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
90 * Array of node states.
92 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
93 [N_POSSIBLE
] = NODE_MASK_ALL
,
94 [N_ONLINE
] = { { [0] = 1UL } },
96 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
98 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
100 #ifdef CONFIG_MOVABLE_NODE
101 [N_MEMORY
] = { { [0] = 1UL } },
103 [N_CPU
] = { { [0] = 1UL } },
106 EXPORT_SYMBOL(node_states
);
108 /* Protect totalram_pages and zone->managed_pages */
109 static DEFINE_SPINLOCK(managed_page_count_lock
);
111 unsigned long totalram_pages __read_mostly
;
112 unsigned long totalreserve_pages __read_mostly
;
114 * When calculating the number of globally allowed dirty pages, there
115 * is a certain number of per-zone reserves that should not be
116 * considered dirtyable memory. This is the sum of those reserves
117 * over all existing zones that contribute dirtyable memory.
119 unsigned long dirty_balance_reserve __read_mostly
;
121 int percpu_pagelist_fraction
;
122 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
124 #ifdef CONFIG_PM_SLEEP
126 * The following functions are used by the suspend/hibernate code to temporarily
127 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
128 * while devices are suspended. To avoid races with the suspend/hibernate code,
129 * they should always be called with pm_mutex held (gfp_allowed_mask also should
130 * only be modified with pm_mutex held, unless the suspend/hibernate code is
131 * guaranteed not to run in parallel with that modification).
134 static gfp_t saved_gfp_mask
;
136 void pm_restore_gfp_mask(void)
138 WARN_ON(!mutex_is_locked(&pm_mutex
));
139 if (saved_gfp_mask
) {
140 gfp_allowed_mask
= saved_gfp_mask
;
145 void pm_restrict_gfp_mask(void)
147 WARN_ON(!mutex_is_locked(&pm_mutex
));
148 WARN_ON(saved_gfp_mask
);
149 saved_gfp_mask
= gfp_allowed_mask
;
150 gfp_allowed_mask
&= ~GFP_IOFS
;
153 bool pm_suspended_storage(void)
155 if ((gfp_allowed_mask
& GFP_IOFS
) == GFP_IOFS
)
159 #endif /* CONFIG_PM_SLEEP */
161 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
162 int pageblock_order __read_mostly
;
165 static void __free_pages_ok(struct page
*page
, unsigned int order
);
168 * results with 256, 32 in the lowmem_reserve sysctl:
169 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
170 * 1G machine -> (16M dma, 784M normal, 224M high)
171 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
172 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
173 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
175 * TBD: should special case ZONE_DMA32 machines here - in those we normally
176 * don't need any ZONE_NORMAL reservation
178 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
179 #ifdef CONFIG_ZONE_DMA
182 #ifdef CONFIG_ZONE_DMA32
185 #ifdef CONFIG_HIGHMEM
191 EXPORT_SYMBOL(totalram_pages
);
193 static char * const zone_names
[MAX_NR_ZONES
] = {
194 #ifdef CONFIG_ZONE_DMA
197 #ifdef CONFIG_ZONE_DMA32
201 #ifdef CONFIG_HIGHMEM
207 int min_free_kbytes
= 1024;
208 int user_min_free_kbytes
= -1;
210 static unsigned long __meminitdata nr_kernel_pages
;
211 static unsigned long __meminitdata nr_all_pages
;
212 static unsigned long __meminitdata dma_reserve
;
214 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
215 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
216 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
217 static unsigned long __initdata required_kernelcore
;
218 static unsigned long __initdata required_movablecore
;
219 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
221 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
223 EXPORT_SYMBOL(movable_zone
);
224 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
227 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
228 int nr_online_nodes __read_mostly
= 1;
229 EXPORT_SYMBOL(nr_node_ids
);
230 EXPORT_SYMBOL(nr_online_nodes
);
233 int page_group_by_mobility_disabled __read_mostly
;
235 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
237 if (unlikely(page_group_by_mobility_disabled
&&
238 migratetype
< MIGRATE_PCPTYPES
))
239 migratetype
= MIGRATE_UNMOVABLE
;
241 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
242 PB_migrate
, PB_migrate_end
);
245 bool oom_killer_disabled __read_mostly
;
247 #ifdef CONFIG_DEBUG_VM
248 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
252 unsigned long pfn
= page_to_pfn(page
);
253 unsigned long sp
, start_pfn
;
256 seq
= zone_span_seqbegin(zone
);
257 start_pfn
= zone
->zone_start_pfn
;
258 sp
= zone
->spanned_pages
;
259 if (!zone_spans_pfn(zone
, pfn
))
261 } while (zone_span_seqretry(zone
, seq
));
264 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
265 pfn
, zone_to_nid(zone
), zone
->name
,
266 start_pfn
, start_pfn
+ sp
);
271 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
273 if (!pfn_valid_within(page_to_pfn(page
)))
275 if (zone
!= page_zone(page
))
281 * Temporary debugging check for pages not lying within a given zone.
283 static int bad_range(struct zone
*zone
, struct page
*page
)
285 if (page_outside_zone_boundaries(zone
, page
))
287 if (!page_is_consistent(zone
, page
))
293 static inline int bad_range(struct zone
*zone
, struct page
*page
)
299 static void bad_page(struct page
*page
, const char *reason
,
300 unsigned long bad_flags
)
302 static unsigned long resume
;
303 static unsigned long nr_shown
;
304 static unsigned long nr_unshown
;
306 /* Don't complain about poisoned pages */
307 if (PageHWPoison(page
)) {
308 page_mapcount_reset(page
); /* remove PageBuddy */
313 * Allow a burst of 60 reports, then keep quiet for that minute;
314 * or allow a steady drip of one report per second.
316 if (nr_shown
== 60) {
317 if (time_before(jiffies
, resume
)) {
323 "BUG: Bad page state: %lu messages suppressed\n",
330 resume
= jiffies
+ 60 * HZ
;
332 printk(KERN_ALERT
"BUG: Bad page state in process %s pfn:%05lx\n",
333 current
->comm
, page_to_pfn(page
));
334 dump_page_badflags(page
, reason
, bad_flags
);
339 /* Leave bad fields for debug, except PageBuddy could make trouble */
340 page_mapcount_reset(page
); /* remove PageBuddy */
341 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
345 * Higher-order pages are called "compound pages". They are structured thusly:
347 * The first PAGE_SIZE page is called the "head page".
349 * The remaining PAGE_SIZE pages are called "tail pages".
351 * All pages have PG_compound set. All tail pages have their ->first_page
352 * pointing at the head page.
354 * The first tail page's ->lru.next holds the address of the compound page's
355 * put_page() function. Its ->lru.prev holds the order of allocation.
356 * This usage means that zero-order pages may not be compound.
359 static void free_compound_page(struct page
*page
)
361 __free_pages_ok(page
, compound_order(page
));
364 void prep_compound_page(struct page
*page
, unsigned long order
)
367 int nr_pages
= 1 << order
;
369 set_compound_page_dtor(page
, free_compound_page
);
370 set_compound_order(page
, order
);
372 for (i
= 1; i
< nr_pages
; i
++) {
373 struct page
*p
= page
+ i
;
374 set_page_count(p
, 0);
375 p
->first_page
= page
;
376 /* Make sure p->first_page is always valid for PageTail() */
382 /* update __split_huge_page_refcount if you change this function */
383 static int destroy_compound_page(struct page
*page
, unsigned long order
)
386 int nr_pages
= 1 << order
;
389 if (unlikely(compound_order(page
) != order
)) {
390 bad_page(page
, "wrong compound order", 0);
394 __ClearPageHead(page
);
396 for (i
= 1; i
< nr_pages
; i
++) {
397 struct page
*p
= page
+ i
;
399 if (unlikely(!PageTail(p
))) {
400 bad_page(page
, "PageTail not set", 0);
402 } else if (unlikely(p
->first_page
!= page
)) {
403 bad_page(page
, "first_page not consistent", 0);
412 static inline void prep_zero_page(struct page
*page
, int order
, gfp_t gfp_flags
)
417 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
418 * and __GFP_HIGHMEM from hard or soft interrupt context.
420 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
421 for (i
= 0; i
< (1 << order
); i
++)
422 clear_highpage(page
+ i
);
425 #ifdef CONFIG_DEBUG_PAGEALLOC
426 unsigned int _debug_guardpage_minorder
;
428 static int __init
debug_guardpage_minorder_setup(char *buf
)
432 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
433 printk(KERN_ERR
"Bad debug_guardpage_minorder value\n");
436 _debug_guardpage_minorder
= res
;
437 printk(KERN_INFO
"Setting debug_guardpage_minorder to %lu\n", res
);
440 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup
);
442 static inline void set_page_guard_flag(struct page
*page
)
444 __set_bit(PAGE_DEBUG_FLAG_GUARD
, &page
->debug_flags
);
447 static inline void clear_page_guard_flag(struct page
*page
)
449 __clear_bit(PAGE_DEBUG_FLAG_GUARD
, &page
->debug_flags
);
452 static inline void set_page_guard_flag(struct page
*page
) { }
453 static inline void clear_page_guard_flag(struct page
*page
) { }
456 static inline void set_page_order(struct page
*page
, int order
)
458 set_page_private(page
, order
);
459 __SetPageBuddy(page
);
462 static inline void rmv_page_order(struct page
*page
)
464 __ClearPageBuddy(page
);
465 set_page_private(page
, 0);
469 * Locate the struct page for both the matching buddy in our
470 * pair (buddy1) and the combined O(n+1) page they form (page).
472 * 1) Any buddy B1 will have an order O twin B2 which satisfies
473 * the following equation:
475 * For example, if the starting buddy (buddy2) is #8 its order
477 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
479 * 2) Any buddy B will have an order O+1 parent P which
480 * satisfies the following equation:
483 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
485 static inline unsigned long
486 __find_buddy_index(unsigned long page_idx
, unsigned int order
)
488 return page_idx
^ (1 << order
);
492 * This function checks whether a page is free && is the buddy
493 * we can do coalesce a page and its buddy if
494 * (a) the buddy is not in a hole &&
495 * (b) the buddy is in the buddy system &&
496 * (c) a page and its buddy have the same order &&
497 * (d) a page and its buddy are in the same zone.
499 * For recording whether a page is in the buddy system, we set ->_mapcount
500 * PAGE_BUDDY_MAPCOUNT_VALUE.
501 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
502 * serialized by zone->lock.
504 * For recording page's order, we use page_private(page).
506 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
509 if (!pfn_valid_within(page_to_pfn(buddy
)))
512 if (page_zone_id(page
) != page_zone_id(buddy
))
515 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
516 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
520 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
521 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
528 * Freeing function for a buddy system allocator.
530 * The concept of a buddy system is to maintain direct-mapped table
531 * (containing bit values) for memory blocks of various "orders".
532 * The bottom level table contains the map for the smallest allocatable
533 * units of memory (here, pages), and each level above it describes
534 * pairs of units from the levels below, hence, "buddies".
535 * At a high level, all that happens here is marking the table entry
536 * at the bottom level available, and propagating the changes upward
537 * as necessary, plus some accounting needed to play nicely with other
538 * parts of the VM system.
539 * At each level, we keep a list of pages, which are heads of continuous
540 * free pages of length of (1 << order) and marked with _mapcount
541 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
543 * So when we are allocating or freeing one, we can derive the state of the
544 * other. That is, if we allocate a small block, and both were
545 * free, the remainder of the region must be split into blocks.
546 * If a block is freed, and its buddy is also free, then this
547 * triggers coalescing into a block of larger size.
552 static inline void __free_one_page(struct page
*page
,
553 struct zone
*zone
, unsigned int order
,
556 unsigned long page_idx
;
557 unsigned long combined_idx
;
558 unsigned long uninitialized_var(buddy_idx
);
561 VM_BUG_ON(!zone_is_initialized(zone
));
563 if (unlikely(PageCompound(page
)))
564 if (unlikely(destroy_compound_page(page
, order
)))
567 VM_BUG_ON(migratetype
== -1);
569 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
571 VM_BUG_ON_PAGE(page_idx
& ((1 << order
) - 1), page
);
572 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
574 while (order
< MAX_ORDER
-1) {
575 buddy_idx
= __find_buddy_index(page_idx
, order
);
576 buddy
= page
+ (buddy_idx
- page_idx
);
577 if (!page_is_buddy(page
, buddy
, order
))
580 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
581 * merge with it and move up one order.
583 if (page_is_guard(buddy
)) {
584 clear_page_guard_flag(buddy
);
585 set_page_private(page
, 0);
586 __mod_zone_freepage_state(zone
, 1 << order
,
589 list_del(&buddy
->lru
);
590 zone
->free_area
[order
].nr_free
--;
591 rmv_page_order(buddy
);
593 combined_idx
= buddy_idx
& page_idx
;
594 page
= page
+ (combined_idx
- page_idx
);
595 page_idx
= combined_idx
;
598 set_page_order(page
, order
);
601 * If this is not the largest possible page, check if the buddy
602 * of the next-highest order is free. If it is, it's possible
603 * that pages are being freed that will coalesce soon. In case,
604 * that is happening, add the free page to the tail of the list
605 * so it's less likely to be used soon and more likely to be merged
606 * as a higher order page
608 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
609 struct page
*higher_page
, *higher_buddy
;
610 combined_idx
= buddy_idx
& page_idx
;
611 higher_page
= page
+ (combined_idx
- page_idx
);
612 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
613 higher_buddy
= higher_page
+ (buddy_idx
- combined_idx
);
614 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
615 list_add_tail(&page
->lru
,
616 &zone
->free_area
[order
].free_list
[migratetype
]);
621 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
623 zone
->free_area
[order
].nr_free
++;
626 static inline int free_pages_check(struct page
*page
)
628 const char *bad_reason
= NULL
;
629 unsigned long bad_flags
= 0;
631 if (unlikely(page_mapcount(page
)))
632 bad_reason
= "nonzero mapcount";
633 if (unlikely(page
->mapping
!= NULL
))
634 bad_reason
= "non-NULL mapping";
635 if (unlikely(atomic_read(&page
->_count
) != 0))
636 bad_reason
= "nonzero _count";
637 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)) {
638 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
639 bad_flags
= PAGE_FLAGS_CHECK_AT_FREE
;
641 if (unlikely(mem_cgroup_bad_page_check(page
)))
642 bad_reason
= "cgroup check failed";
643 if (unlikely(bad_reason
)) {
644 bad_page(page
, bad_reason
, bad_flags
);
647 page_cpupid_reset_last(page
);
648 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
649 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
654 * Frees a number of pages from the PCP lists
655 * Assumes all pages on list are in same zone, and of same order.
656 * count is the number of pages to free.
658 * If the zone was previously in an "all pages pinned" state then look to
659 * see if this freeing clears that state.
661 * And clear the zone's pages_scanned counter, to hold off the "all pages are
662 * pinned" detection logic.
664 static void free_pcppages_bulk(struct zone
*zone
, int count
,
665 struct per_cpu_pages
*pcp
)
671 spin_lock(&zone
->lock
);
672 zone
->pages_scanned
= 0;
676 struct list_head
*list
;
679 * Remove pages from lists in a round-robin fashion. A
680 * batch_free count is maintained that is incremented when an
681 * empty list is encountered. This is so more pages are freed
682 * off fuller lists instead of spinning excessively around empty
687 if (++migratetype
== MIGRATE_PCPTYPES
)
689 list
= &pcp
->lists
[migratetype
];
690 } while (list_empty(list
));
692 /* This is the only non-empty list. Free them all. */
693 if (batch_free
== MIGRATE_PCPTYPES
)
694 batch_free
= to_free
;
697 int mt
; /* migratetype of the to-be-freed page */
699 page
= list_entry(list
->prev
, struct page
, lru
);
700 /* must delete as __free_one_page list manipulates */
701 list_del(&page
->lru
);
702 mt
= get_freepage_migratetype(page
);
703 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
704 __free_one_page(page
, zone
, 0, mt
);
705 trace_mm_page_pcpu_drain(page
, 0, mt
);
706 if (likely(!is_migrate_isolate_page(page
))) {
707 __mod_zone_page_state(zone
, NR_FREE_PAGES
, 1);
708 if (is_migrate_cma(mt
))
709 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
, 1);
711 } while (--to_free
&& --batch_free
&& !list_empty(list
));
713 spin_unlock(&zone
->lock
);
716 static void free_one_page(struct zone
*zone
, struct page
*page
, int order
,
719 spin_lock(&zone
->lock
);
720 zone
->pages_scanned
= 0;
722 __free_one_page(page
, zone
, order
, migratetype
);
723 if (unlikely(!is_migrate_isolate(migratetype
)))
724 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
725 spin_unlock(&zone
->lock
);
728 static bool free_pages_prepare(struct page
*page
, unsigned int order
)
733 trace_mm_page_free(page
, order
);
734 kmemcheck_free_shadow(page
, order
);
737 page
->mapping
= NULL
;
738 for (i
= 0; i
< (1 << order
); i
++)
739 bad
+= free_pages_check(page
+ i
);
743 if (!PageHighMem(page
)) {
744 debug_check_no_locks_freed(page_address(page
),
746 debug_check_no_obj_freed(page_address(page
),
749 arch_free_page(page
, order
);
750 kernel_map_pages(page
, 1 << order
, 0);
755 static void __free_pages_ok(struct page
*page
, unsigned int order
)
760 if (!free_pages_prepare(page
, order
))
763 local_irq_save(flags
);
764 __count_vm_events(PGFREE
, 1 << order
);
765 migratetype
= get_pageblock_migratetype(page
);
766 set_freepage_migratetype(page
, migratetype
);
767 free_one_page(page_zone(page
), page
, order
, migratetype
);
768 local_irq_restore(flags
);
771 void __init
__free_pages_bootmem(struct page
*page
, unsigned int order
)
773 unsigned int nr_pages
= 1 << order
;
774 struct page
*p
= page
;
778 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
780 __ClearPageReserved(p
);
781 set_page_count(p
, 0);
783 __ClearPageReserved(p
);
784 set_page_count(p
, 0);
786 page_zone(page
)->managed_pages
+= nr_pages
;
787 set_page_refcounted(page
);
788 __free_pages(page
, order
);
792 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
793 void __init
init_cma_reserved_pageblock(struct page
*page
)
795 unsigned i
= pageblock_nr_pages
;
796 struct page
*p
= page
;
799 __ClearPageReserved(p
);
800 set_page_count(p
, 0);
803 set_page_refcounted(page
);
804 set_pageblock_migratetype(page
, MIGRATE_CMA
);
805 __free_pages(page
, pageblock_order
);
806 adjust_managed_page_count(page
, pageblock_nr_pages
);
811 * The order of subdivision here is critical for the IO subsystem.
812 * Please do not alter this order without good reasons and regression
813 * testing. Specifically, as large blocks of memory are subdivided,
814 * the order in which smaller blocks are delivered depends on the order
815 * they're subdivided in this function. This is the primary factor
816 * influencing the order in which pages are delivered to the IO
817 * subsystem according to empirical testing, and this is also justified
818 * by considering the behavior of a buddy system containing a single
819 * large block of memory acted on by a series of small allocations.
820 * This behavior is a critical factor in sglist merging's success.
824 static inline void expand(struct zone
*zone
, struct page
*page
,
825 int low
, int high
, struct free_area
*area
,
828 unsigned long size
= 1 << high
;
834 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
836 #ifdef CONFIG_DEBUG_PAGEALLOC
837 if (high
< debug_guardpage_minorder()) {
839 * Mark as guard pages (or page), that will allow to
840 * merge back to allocator when buddy will be freed.
841 * Corresponding page table entries will not be touched,
842 * pages will stay not present in virtual address space
844 INIT_LIST_HEAD(&page
[size
].lru
);
845 set_page_guard_flag(&page
[size
]);
846 set_page_private(&page
[size
], high
);
847 /* Guard pages are not available for any usage */
848 __mod_zone_freepage_state(zone
, -(1 << high
),
853 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
855 set_page_order(&page
[size
], high
);
860 * This page is about to be returned from the page allocator
862 static inline int check_new_page(struct page
*page
)
864 const char *bad_reason
= NULL
;
865 unsigned long bad_flags
= 0;
867 if (unlikely(page_mapcount(page
)))
868 bad_reason
= "nonzero mapcount";
869 if (unlikely(page
->mapping
!= NULL
))
870 bad_reason
= "non-NULL mapping";
871 if (unlikely(atomic_read(&page
->_count
) != 0))
872 bad_reason
= "nonzero _count";
873 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)) {
874 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag set";
875 bad_flags
= PAGE_FLAGS_CHECK_AT_PREP
;
877 if (unlikely(mem_cgroup_bad_page_check(page
)))
878 bad_reason
= "cgroup check failed";
879 if (unlikely(bad_reason
)) {
880 bad_page(page
, bad_reason
, bad_flags
);
886 static int prep_new_page(struct page
*page
, int order
, gfp_t gfp_flags
)
890 for (i
= 0; i
< (1 << order
); i
++) {
891 struct page
*p
= page
+ i
;
892 if (unlikely(check_new_page(p
)))
896 set_page_private(page
, 0);
897 set_page_refcounted(page
);
899 arch_alloc_page(page
, order
);
900 kernel_map_pages(page
, 1 << order
, 1);
902 if (gfp_flags
& __GFP_ZERO
)
903 prep_zero_page(page
, order
, gfp_flags
);
905 if (order
&& (gfp_flags
& __GFP_COMP
))
906 prep_compound_page(page
, order
);
912 * Go through the free lists for the given migratetype and remove
913 * the smallest available page from the freelists
916 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
919 unsigned int current_order
;
920 struct free_area
*area
;
923 /* Find a page of the appropriate size in the preferred list */
924 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
925 area
= &(zone
->free_area
[current_order
]);
926 if (list_empty(&area
->free_list
[migratetype
]))
929 page
= list_entry(area
->free_list
[migratetype
].next
,
931 list_del(&page
->lru
);
932 rmv_page_order(page
);
934 expand(zone
, page
, order
, current_order
, area
, migratetype
);
935 set_freepage_migratetype(page
, migratetype
);
944 * This array describes the order lists are fallen back to when
945 * the free lists for the desirable migrate type are depleted
947 static int fallbacks
[MIGRATE_TYPES
][4] = {
948 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
949 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
951 [MIGRATE_MOVABLE
] = { MIGRATE_CMA
, MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
952 [MIGRATE_CMA
] = { MIGRATE_RESERVE
}, /* Never used */
954 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
956 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
}, /* Never used */
957 #ifdef CONFIG_MEMORY_ISOLATION
958 [MIGRATE_ISOLATE
] = { MIGRATE_RESERVE
}, /* Never used */
963 * Move the free pages in a range to the free lists of the requested type.
964 * Note that start_page and end_pages are not aligned on a pageblock
965 * boundary. If alignment is required, use move_freepages_block()
967 int move_freepages(struct zone
*zone
,
968 struct page
*start_page
, struct page
*end_page
,
975 #ifndef CONFIG_HOLES_IN_ZONE
977 * page_zone is not safe to call in this context when
978 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
979 * anyway as we check zone boundaries in move_freepages_block().
980 * Remove at a later date when no bug reports exist related to
981 * grouping pages by mobility
983 BUG_ON(page_zone(start_page
) != page_zone(end_page
));
986 for (page
= start_page
; page
<= end_page
;) {
987 /* Make sure we are not inadvertently changing nodes */
988 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
990 if (!pfn_valid_within(page_to_pfn(page
))) {
995 if (!PageBuddy(page
)) {
1000 order
= page_order(page
);
1001 list_move(&page
->lru
,
1002 &zone
->free_area
[order
].free_list
[migratetype
]);
1003 set_freepage_migratetype(page
, migratetype
);
1005 pages_moved
+= 1 << order
;
1011 int move_freepages_block(struct zone
*zone
, struct page
*page
,
1014 unsigned long start_pfn
, end_pfn
;
1015 struct page
*start_page
, *end_page
;
1017 start_pfn
= page_to_pfn(page
);
1018 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
1019 start_page
= pfn_to_page(start_pfn
);
1020 end_page
= start_page
+ pageblock_nr_pages
- 1;
1021 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
1023 /* Do not cross zone boundaries */
1024 if (!zone_spans_pfn(zone
, start_pfn
))
1026 if (!zone_spans_pfn(zone
, end_pfn
))
1029 return move_freepages(zone
, start_page
, end_page
, migratetype
);
1032 static void change_pageblock_range(struct page
*pageblock_page
,
1033 int start_order
, int migratetype
)
1035 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
1037 while (nr_pageblocks
--) {
1038 set_pageblock_migratetype(pageblock_page
, migratetype
);
1039 pageblock_page
+= pageblock_nr_pages
;
1044 * If breaking a large block of pages, move all free pages to the preferred
1045 * allocation list. If falling back for a reclaimable kernel allocation, be
1046 * more aggressive about taking ownership of free pages.
1048 * On the other hand, never change migration type of MIGRATE_CMA pageblocks
1049 * nor move CMA pages to different free lists. We don't want unmovable pages
1050 * to be allocated from MIGRATE_CMA areas.
1052 * Returns the new migratetype of the pageblock (or the same old migratetype
1053 * if it was unchanged).
1055 static int try_to_steal_freepages(struct zone
*zone
, struct page
*page
,
1056 int start_type
, int fallback_type
)
1058 int current_order
= page_order(page
);
1061 * When borrowing from MIGRATE_CMA, we need to release the excess
1062 * buddy pages to CMA itself. We also ensure the freepage_migratetype
1063 * is set to CMA so it is returned to the correct freelist in case
1064 * the page ends up being not actually allocated from the pcp lists.
1066 if (is_migrate_cma(fallback_type
))
1067 return fallback_type
;
1069 /* Take ownership for orders >= pageblock_order */
1070 if (current_order
>= pageblock_order
) {
1071 change_pageblock_range(page
, current_order
, start_type
);
1075 if (current_order
>= pageblock_order
/ 2 ||
1076 start_type
== MIGRATE_RECLAIMABLE
||
1077 page_group_by_mobility_disabled
) {
1080 pages
= move_freepages_block(zone
, page
, start_type
);
1082 /* Claim the whole block if over half of it is free */
1083 if (pages
>= (1 << (pageblock_order
-1)) ||
1084 page_group_by_mobility_disabled
) {
1086 set_pageblock_migratetype(page
, start_type
);
1092 return fallback_type
;
1095 /* Remove an element from the buddy allocator from the fallback list */
1096 static inline struct page
*
1097 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
)
1099 struct free_area
*area
;
1102 int migratetype
, new_type
, i
;
1104 /* Find the largest possible block of pages in the other list */
1105 for (current_order
= MAX_ORDER
-1; current_order
>= order
;
1108 migratetype
= fallbacks
[start_migratetype
][i
];
1110 /* MIGRATE_RESERVE handled later if necessary */
1111 if (migratetype
== MIGRATE_RESERVE
)
1114 area
= &(zone
->free_area
[current_order
]);
1115 if (list_empty(&area
->free_list
[migratetype
]))
1118 page
= list_entry(area
->free_list
[migratetype
].next
,
1122 new_type
= try_to_steal_freepages(zone
, page
,
1126 /* Remove the page from the freelists */
1127 list_del(&page
->lru
);
1128 rmv_page_order(page
);
1130 expand(zone
, page
, order
, current_order
, area
,
1132 /* The freepage_migratetype may differ from pageblock's
1133 * migratetype depending on the decisions in
1134 * try_to_steal_freepages. This is OK as long as it does
1135 * not differ for MIGRATE_CMA type.
1137 set_freepage_migratetype(page
, new_type
);
1139 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
1140 start_migratetype
, migratetype
, new_type
);
1150 * Do the hard work of removing an element from the buddy allocator.
1151 * Call me with the zone->lock already held.
1153 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
1159 page
= __rmqueue_smallest(zone
, order
, migratetype
);
1161 if (unlikely(!page
) && migratetype
!= MIGRATE_RESERVE
) {
1162 page
= __rmqueue_fallback(zone
, order
, migratetype
);
1165 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1166 * is used because __rmqueue_smallest is an inline function
1167 * and we want just one call site
1170 migratetype
= MIGRATE_RESERVE
;
1175 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
1180 * Obtain a specified number of elements from the buddy allocator, all under
1181 * a single hold of the lock, for efficiency. Add them to the supplied list.
1182 * Returns the number of new pages which were placed at *list.
1184 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
1185 unsigned long count
, struct list_head
*list
,
1186 int migratetype
, int cold
)
1190 spin_lock(&zone
->lock
);
1191 for (i
= 0; i
< count
; ++i
) {
1192 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
1193 if (unlikely(page
== NULL
))
1197 * Split buddy pages returned by expand() are received here
1198 * in physical page order. The page is added to the callers and
1199 * list and the list head then moves forward. From the callers
1200 * perspective, the linked list is ordered by page number in
1201 * some conditions. This is useful for IO devices that can
1202 * merge IO requests if the physical pages are ordered
1205 if (likely(cold
== 0))
1206 list_add(&page
->lru
, list
);
1208 list_add_tail(&page
->lru
, list
);
1210 if (is_migrate_cma(get_freepage_migratetype(page
)))
1211 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
1214 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
1215 spin_unlock(&zone
->lock
);
1221 * Called from the vmstat counter updater to drain pagesets of this
1222 * currently executing processor on remote nodes after they have
1225 * Note that this function must be called with the thread pinned to
1226 * a single processor.
1228 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
1230 unsigned long flags
;
1232 unsigned long batch
;
1234 local_irq_save(flags
);
1235 batch
= ACCESS_ONCE(pcp
->batch
);
1236 if (pcp
->count
>= batch
)
1239 to_drain
= pcp
->count
;
1241 free_pcppages_bulk(zone
, to_drain
, pcp
);
1242 pcp
->count
-= to_drain
;
1244 local_irq_restore(flags
);
1249 * Drain pages of the indicated processor.
1251 * The processor must either be the current processor and the
1252 * thread pinned to the current processor or a processor that
1255 static void drain_pages(unsigned int cpu
)
1257 unsigned long flags
;
1260 for_each_populated_zone(zone
) {
1261 struct per_cpu_pageset
*pset
;
1262 struct per_cpu_pages
*pcp
;
1264 local_irq_save(flags
);
1265 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
1269 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
1272 local_irq_restore(flags
);
1277 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1279 void drain_local_pages(void *arg
)
1281 drain_pages(smp_processor_id());
1285 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
1287 * Note that this code is protected against sending an IPI to an offline
1288 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
1289 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
1290 * nothing keeps CPUs from showing up after we populated the cpumask and
1291 * before the call to on_each_cpu_mask().
1293 void drain_all_pages(void)
1296 struct per_cpu_pageset
*pcp
;
1300 * Allocate in the BSS so we wont require allocation in
1301 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
1303 static cpumask_t cpus_with_pcps
;
1306 * We don't care about racing with CPU hotplug event
1307 * as offline notification will cause the notified
1308 * cpu to drain that CPU pcps and on_each_cpu_mask
1309 * disables preemption as part of its processing
1311 for_each_online_cpu(cpu
) {
1312 bool has_pcps
= false;
1313 for_each_populated_zone(zone
) {
1314 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
1315 if (pcp
->pcp
.count
) {
1321 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
1323 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
1325 on_each_cpu_mask(&cpus_with_pcps
, drain_local_pages
, NULL
, 1);
1328 #ifdef CONFIG_HIBERNATION
1330 void mark_free_pages(struct zone
*zone
)
1332 unsigned long pfn
, max_zone_pfn
;
1333 unsigned long flags
;
1335 struct list_head
*curr
;
1337 if (zone_is_empty(zone
))
1340 spin_lock_irqsave(&zone
->lock
, flags
);
1342 max_zone_pfn
= zone_end_pfn(zone
);
1343 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1344 if (pfn_valid(pfn
)) {
1345 struct page
*page
= pfn_to_page(pfn
);
1347 if (!swsusp_page_is_forbidden(page
))
1348 swsusp_unset_page_free(page
);
1351 for_each_migratetype_order(order
, t
) {
1352 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
1355 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
1356 for (i
= 0; i
< (1UL << order
); i
++)
1357 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
1360 spin_unlock_irqrestore(&zone
->lock
, flags
);
1362 #endif /* CONFIG_PM */
1365 * Free a 0-order page
1366 * cold == 1 ? free a cold page : free a hot page
1368 void free_hot_cold_page(struct page
*page
, int cold
)
1370 struct zone
*zone
= page_zone(page
);
1371 struct per_cpu_pages
*pcp
;
1372 unsigned long flags
;
1375 if (!free_pages_prepare(page
, 0))
1378 migratetype
= get_pageblock_migratetype(page
);
1379 set_freepage_migratetype(page
, migratetype
);
1380 local_irq_save(flags
);
1381 __count_vm_event(PGFREE
);
1384 * We only track unmovable, reclaimable and movable on pcp lists.
1385 * Free ISOLATE pages back to the allocator because they are being
1386 * offlined but treat RESERVE as movable pages so we can get those
1387 * areas back if necessary. Otherwise, we may have to free
1388 * excessively into the page allocator
1390 if (migratetype
>= MIGRATE_PCPTYPES
) {
1391 if (unlikely(is_migrate_isolate(migratetype
))) {
1392 free_one_page(zone
, page
, 0, migratetype
);
1395 migratetype
= MIGRATE_MOVABLE
;
1398 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1400 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
1402 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
1404 if (pcp
->count
>= pcp
->high
) {
1405 unsigned long batch
= ACCESS_ONCE(pcp
->batch
);
1406 free_pcppages_bulk(zone
, batch
, pcp
);
1407 pcp
->count
-= batch
;
1411 local_irq_restore(flags
);
1415 * Free a list of 0-order pages
1417 void free_hot_cold_page_list(struct list_head
*list
, int cold
)
1419 struct page
*page
, *next
;
1421 list_for_each_entry_safe(page
, next
, list
, lru
) {
1422 trace_mm_page_free_batched(page
, cold
);
1423 free_hot_cold_page(page
, cold
);
1428 * split_page takes a non-compound higher-order page, and splits it into
1429 * n (1<<order) sub-pages: page[0..n]
1430 * Each sub-page must be freed individually.
1432 * Note: this is probably too low level an operation for use in drivers.
1433 * Please consult with lkml before using this in your driver.
1435 void split_page(struct page
*page
, unsigned int order
)
1439 VM_BUG_ON_PAGE(PageCompound(page
), page
);
1440 VM_BUG_ON_PAGE(!page_count(page
), page
);
1442 #ifdef CONFIG_KMEMCHECK
1444 * Split shadow pages too, because free(page[0]) would
1445 * otherwise free the whole shadow.
1447 if (kmemcheck_page_is_tracked(page
))
1448 split_page(virt_to_page(page
[0].shadow
), order
);
1451 for (i
= 1; i
< (1 << order
); i
++)
1452 set_page_refcounted(page
+ i
);
1454 EXPORT_SYMBOL_GPL(split_page
);
1456 static int __isolate_free_page(struct page
*page
, unsigned int order
)
1458 unsigned long watermark
;
1462 BUG_ON(!PageBuddy(page
));
1464 zone
= page_zone(page
);
1465 mt
= get_pageblock_migratetype(page
);
1467 if (!is_migrate_isolate(mt
)) {
1468 /* Obey watermarks as if the page was being allocated */
1469 watermark
= low_wmark_pages(zone
) + (1 << order
);
1470 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
1473 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
1476 /* Remove page from free list */
1477 list_del(&page
->lru
);
1478 zone
->free_area
[order
].nr_free
--;
1479 rmv_page_order(page
);
1481 /* Set the pageblock if the isolated page is at least a pageblock */
1482 if (order
>= pageblock_order
- 1) {
1483 struct page
*endpage
= page
+ (1 << order
) - 1;
1484 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
1485 int mt
= get_pageblock_migratetype(page
);
1486 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
))
1487 set_pageblock_migratetype(page
,
1492 return 1UL << order
;
1496 * Similar to split_page except the page is already free. As this is only
1497 * being used for migration, the migratetype of the block also changes.
1498 * As this is called with interrupts disabled, the caller is responsible
1499 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1502 * Note: this is probably too low level an operation for use in drivers.
1503 * Please consult with lkml before using this in your driver.
1505 int split_free_page(struct page
*page
)
1510 order
= page_order(page
);
1512 nr_pages
= __isolate_free_page(page
, order
);
1516 /* Split into individual pages */
1517 set_page_refcounted(page
);
1518 split_page(page
, order
);
1523 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1524 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1528 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
1529 struct zone
*zone
, int order
, gfp_t gfp_flags
,
1532 unsigned long flags
;
1534 int cold
= !!(gfp_flags
& __GFP_COLD
);
1537 if (likely(order
== 0)) {
1538 struct per_cpu_pages
*pcp
;
1539 struct list_head
*list
;
1541 local_irq_save(flags
);
1542 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1543 list
= &pcp
->lists
[migratetype
];
1544 if (list_empty(list
)) {
1545 pcp
->count
+= rmqueue_bulk(zone
, 0,
1548 if (unlikely(list_empty(list
)))
1553 page
= list_entry(list
->prev
, struct page
, lru
);
1555 page
= list_entry(list
->next
, struct page
, lru
);
1557 list_del(&page
->lru
);
1560 if (unlikely(gfp_flags
& __GFP_NOFAIL
)) {
1562 * __GFP_NOFAIL is not to be used in new code.
1564 * All __GFP_NOFAIL callers should be fixed so that they
1565 * properly detect and handle allocation failures.
1567 * We most definitely don't want callers attempting to
1568 * allocate greater than order-1 page units with
1571 WARN_ON_ONCE(order
> 1);
1573 spin_lock_irqsave(&zone
->lock
, flags
);
1574 page
= __rmqueue(zone
, order
, migratetype
);
1575 spin_unlock(&zone
->lock
);
1578 __mod_zone_freepage_state(zone
, -(1 << order
),
1579 get_freepage_migratetype(page
));
1582 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
, -(1 << order
));
1584 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
1585 zone_statistics(preferred_zone
, zone
, gfp_flags
);
1586 local_irq_restore(flags
);
1588 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
1589 if (prep_new_page(page
, order
, gfp_flags
))
1594 local_irq_restore(flags
);
1598 #ifdef CONFIG_FAIL_PAGE_ALLOC
1601 struct fault_attr attr
;
1603 u32 ignore_gfp_highmem
;
1604 u32 ignore_gfp_wait
;
1606 } fail_page_alloc
= {
1607 .attr
= FAULT_ATTR_INITIALIZER
,
1608 .ignore_gfp_wait
= 1,
1609 .ignore_gfp_highmem
= 1,
1613 static int __init
setup_fail_page_alloc(char *str
)
1615 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
1617 __setup("fail_page_alloc=", setup_fail_page_alloc
);
1619 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1621 if (order
< fail_page_alloc
.min_order
)
1623 if (gfp_mask
& __GFP_NOFAIL
)
1625 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
1627 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
1630 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
1633 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1635 static int __init
fail_page_alloc_debugfs(void)
1637 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
1640 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
1641 &fail_page_alloc
.attr
);
1643 return PTR_ERR(dir
);
1645 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
1646 &fail_page_alloc
.ignore_gfp_wait
))
1648 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
1649 &fail_page_alloc
.ignore_gfp_highmem
))
1651 if (!debugfs_create_u32("min-order", mode
, dir
,
1652 &fail_page_alloc
.min_order
))
1657 debugfs_remove_recursive(dir
);
1662 late_initcall(fail_page_alloc_debugfs
);
1664 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1666 #else /* CONFIG_FAIL_PAGE_ALLOC */
1668 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1673 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1676 * Return true if free pages are above 'mark'. This takes into account the order
1677 * of the allocation.
1679 static bool __zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1680 int classzone_idx
, int alloc_flags
, long free_pages
)
1682 /* free_pages my go negative - that's OK */
1684 long lowmem_reserve
= z
->lowmem_reserve
[classzone_idx
];
1688 free_pages
-= (1 << order
) - 1;
1689 if (alloc_flags
& ALLOC_HIGH
)
1691 if (alloc_flags
& ALLOC_HARDER
)
1694 /* If allocation can't use CMA areas don't use free CMA pages */
1695 if (!(alloc_flags
& ALLOC_CMA
))
1696 free_cma
= zone_page_state(z
, NR_FREE_CMA_PAGES
);
1699 if (free_pages
- free_cma
<= min
+ lowmem_reserve
)
1701 for (o
= 0; o
< order
; o
++) {
1702 /* At the next order, this order's pages become unavailable */
1703 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
1705 /* Require fewer higher order pages to be free */
1708 if (free_pages
<= min
)
1714 bool zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1715 int classzone_idx
, int alloc_flags
)
1717 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1718 zone_page_state(z
, NR_FREE_PAGES
));
1721 bool zone_watermark_ok_safe(struct zone
*z
, int order
, unsigned long mark
,
1722 int classzone_idx
, int alloc_flags
)
1724 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
1726 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
1727 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
1729 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1735 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1736 * skip over zones that are not allowed by the cpuset, or that have
1737 * been recently (in last second) found to be nearly full. See further
1738 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1739 * that have to skip over a lot of full or unallowed zones.
1741 * If the zonelist cache is present in the passed zonelist, then
1742 * returns a pointer to the allowed node mask (either the current
1743 * tasks mems_allowed, or node_states[N_MEMORY].)
1745 * If the zonelist cache is not available for this zonelist, does
1746 * nothing and returns NULL.
1748 * If the fullzones BITMAP in the zonelist cache is stale (more than
1749 * a second since last zap'd) then we zap it out (clear its bits.)
1751 * We hold off even calling zlc_setup, until after we've checked the
1752 * first zone in the zonelist, on the theory that most allocations will
1753 * be satisfied from that first zone, so best to examine that zone as
1754 * quickly as we can.
1756 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1758 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1759 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
1761 zlc
= zonelist
->zlcache_ptr
;
1765 if (time_after(jiffies
, zlc
->last_full_zap
+ HZ
)) {
1766 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1767 zlc
->last_full_zap
= jiffies
;
1770 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
1771 &cpuset_current_mems_allowed
:
1772 &node_states
[N_MEMORY
];
1773 return allowednodes
;
1777 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1778 * if it is worth looking at further for free memory:
1779 * 1) Check that the zone isn't thought to be full (doesn't have its
1780 * bit set in the zonelist_cache fullzones BITMAP).
1781 * 2) Check that the zones node (obtained from the zonelist_cache
1782 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1783 * Return true (non-zero) if zone is worth looking at further, or
1784 * else return false (zero) if it is not.
1786 * This check -ignores- the distinction between various watermarks,
1787 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1788 * found to be full for any variation of these watermarks, it will
1789 * be considered full for up to one second by all requests, unless
1790 * we are so low on memory on all allowed nodes that we are forced
1791 * into the second scan of the zonelist.
1793 * In the second scan we ignore this zonelist cache and exactly
1794 * apply the watermarks to all zones, even it is slower to do so.
1795 * We are low on memory in the second scan, and should leave no stone
1796 * unturned looking for a free page.
1798 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1799 nodemask_t
*allowednodes
)
1801 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1802 int i
; /* index of *z in zonelist zones */
1803 int n
; /* node that zone *z is on */
1805 zlc
= zonelist
->zlcache_ptr
;
1809 i
= z
- zonelist
->_zonerefs
;
1812 /* This zone is worth trying if it is allowed but not full */
1813 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1817 * Given 'z' scanning a zonelist, set the corresponding bit in
1818 * zlc->fullzones, so that subsequent attempts to allocate a page
1819 * from that zone don't waste time re-examining it.
1821 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1823 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1824 int i
; /* index of *z in zonelist zones */
1826 zlc
= zonelist
->zlcache_ptr
;
1830 i
= z
- zonelist
->_zonerefs
;
1832 set_bit(i
, zlc
->fullzones
);
1836 * clear all zones full, called after direct reclaim makes progress so that
1837 * a zone that was recently full is not skipped over for up to a second
1839 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
1841 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1843 zlc
= zonelist
->zlcache_ptr
;
1847 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1850 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
1852 return local_zone
->node
== zone
->node
;
1855 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
1857 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <
1861 #else /* CONFIG_NUMA */
1863 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1868 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1869 nodemask_t
*allowednodes
)
1874 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1878 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
1882 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
1887 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
1892 #endif /* CONFIG_NUMA */
1895 * get_page_from_freelist goes through the zonelist trying to allocate
1898 static struct page
*
1899 get_page_from_freelist(gfp_t gfp_mask
, nodemask_t
*nodemask
, unsigned int order
,
1900 struct zonelist
*zonelist
, int high_zoneidx
, int alloc_flags
,
1901 struct zone
*preferred_zone
, int migratetype
)
1904 struct page
*page
= NULL
;
1907 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
1908 int zlc_active
= 0; /* set if using zonelist_cache */
1909 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
1911 classzone_idx
= zone_idx(preferred_zone
);
1914 * Scan zonelist, looking for a zone with enough free.
1915 * See also __cpuset_node_allowed_softwall() comment in kernel/cpuset.c.
1917 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
1918 high_zoneidx
, nodemask
) {
1921 if (IS_ENABLED(CONFIG_NUMA
) && zlc_active
&&
1922 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1924 if ((alloc_flags
& ALLOC_CPUSET
) &&
1925 !cpuset_zone_allowed_softwall(zone
, gfp_mask
))
1927 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
1928 if (unlikely(alloc_flags
& ALLOC_NO_WATERMARKS
))
1931 * Distribute pages in proportion to the individual
1932 * zone size to ensure fair page aging. The zone a
1933 * page was allocated in should have no effect on the
1934 * time the page has in memory before being reclaimed.
1936 if (alloc_flags
& ALLOC_FAIR
) {
1937 if (!zone_local(preferred_zone
, zone
))
1939 if (zone_page_state(zone
, NR_ALLOC_BATCH
) <= 0)
1943 * When allocating a page cache page for writing, we
1944 * want to get it from a zone that is within its dirty
1945 * limit, such that no single zone holds more than its
1946 * proportional share of globally allowed dirty pages.
1947 * The dirty limits take into account the zone's
1948 * lowmem reserves and high watermark so that kswapd
1949 * should be able to balance it without having to
1950 * write pages from its LRU list.
1952 * This may look like it could increase pressure on
1953 * lower zones by failing allocations in higher zones
1954 * before they are full. But the pages that do spill
1955 * over are limited as the lower zones are protected
1956 * by this very same mechanism. It should not become
1957 * a practical burden to them.
1959 * XXX: For now, allow allocations to potentially
1960 * exceed the per-zone dirty limit in the slowpath
1961 * (ALLOC_WMARK_LOW unset) before going into reclaim,
1962 * which is important when on a NUMA setup the allowed
1963 * zones are together not big enough to reach the
1964 * global limit. The proper fix for these situations
1965 * will require awareness of zones in the
1966 * dirty-throttling and the flusher threads.
1968 if ((alloc_flags
& ALLOC_WMARK_LOW
) &&
1969 (gfp_mask
& __GFP_WRITE
) && !zone_dirty_ok(zone
))
1972 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
1973 if (!zone_watermark_ok(zone
, order
, mark
,
1974 classzone_idx
, alloc_flags
)) {
1977 if (IS_ENABLED(CONFIG_NUMA
) &&
1978 !did_zlc_setup
&& nr_online_nodes
> 1) {
1980 * we do zlc_setup if there are multiple nodes
1981 * and before considering the first zone allowed
1984 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
1989 if (zone_reclaim_mode
== 0 ||
1990 !zone_allows_reclaim(preferred_zone
, zone
))
1991 goto this_zone_full
;
1994 * As we may have just activated ZLC, check if the first
1995 * eligible zone has failed zone_reclaim recently.
1997 if (IS_ENABLED(CONFIG_NUMA
) && zlc_active
&&
1998 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
2001 ret
= zone_reclaim(zone
, gfp_mask
, order
);
2003 case ZONE_RECLAIM_NOSCAN
:
2006 case ZONE_RECLAIM_FULL
:
2007 /* scanned but unreclaimable */
2010 /* did we reclaim enough */
2011 if (zone_watermark_ok(zone
, order
, mark
,
2012 classzone_idx
, alloc_flags
))
2016 * Failed to reclaim enough to meet watermark.
2017 * Only mark the zone full if checking the min
2018 * watermark or if we failed to reclaim just
2019 * 1<<order pages or else the page allocator
2020 * fastpath will prematurely mark zones full
2021 * when the watermark is between the low and
2024 if (((alloc_flags
& ALLOC_WMARK_MASK
) == ALLOC_WMARK_MIN
) ||
2025 ret
== ZONE_RECLAIM_SOME
)
2026 goto this_zone_full
;
2033 page
= buffered_rmqueue(preferred_zone
, zone
, order
,
2034 gfp_mask
, migratetype
);
2038 if (IS_ENABLED(CONFIG_NUMA
) && zlc_active
)
2039 zlc_mark_zone_full(zonelist
, z
);
2042 if (unlikely(IS_ENABLED(CONFIG_NUMA
) && page
== NULL
&& zlc_active
)) {
2043 /* Disable zlc cache for second zonelist scan */
2050 * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was
2051 * necessary to allocate the page. The expectation is
2052 * that the caller is taking steps that will free more
2053 * memory. The caller should avoid the page being used
2054 * for !PFMEMALLOC purposes.
2056 page
->pfmemalloc
= !!(alloc_flags
& ALLOC_NO_WATERMARKS
);
2062 * Large machines with many possible nodes should not always dump per-node
2063 * meminfo in irq context.
2065 static inline bool should_suppress_show_mem(void)
2070 ret
= in_interrupt();
2075 static DEFINE_RATELIMIT_STATE(nopage_rs
,
2076 DEFAULT_RATELIMIT_INTERVAL
,
2077 DEFAULT_RATELIMIT_BURST
);
2079 void warn_alloc_failed(gfp_t gfp_mask
, int order
, const char *fmt
, ...)
2081 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
2083 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
2084 debug_guardpage_minorder() > 0)
2088 * This documents exceptions given to allocations in certain
2089 * contexts that are allowed to allocate outside current's set
2092 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2093 if (test_thread_flag(TIF_MEMDIE
) ||
2094 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
2095 filter
&= ~SHOW_MEM_FILTER_NODES
;
2096 if (in_interrupt() || !(gfp_mask
& __GFP_WAIT
))
2097 filter
&= ~SHOW_MEM_FILTER_NODES
;
2100 struct va_format vaf
;
2103 va_start(args
, fmt
);
2108 pr_warn("%pV", &vaf
);
2113 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
2114 current
->comm
, order
, gfp_mask
);
2117 if (!should_suppress_show_mem())
2122 should_alloc_retry(gfp_t gfp_mask
, unsigned int order
,
2123 unsigned long did_some_progress
,
2124 unsigned long pages_reclaimed
)
2126 /* Do not loop if specifically requested */
2127 if (gfp_mask
& __GFP_NORETRY
)
2130 /* Always retry if specifically requested */
2131 if (gfp_mask
& __GFP_NOFAIL
)
2135 * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
2136 * making forward progress without invoking OOM. Suspend also disables
2137 * storage devices so kswapd will not help. Bail if we are suspending.
2139 if (!did_some_progress
&& pm_suspended_storage())
2143 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
2144 * means __GFP_NOFAIL, but that may not be true in other
2147 if (order
<= PAGE_ALLOC_COSTLY_ORDER
)
2151 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
2152 * specified, then we retry until we no longer reclaim any pages
2153 * (above), or we've reclaimed an order of pages at least as
2154 * large as the allocation's order. In both cases, if the
2155 * allocation still fails, we stop retrying.
2157 if (gfp_mask
& __GFP_REPEAT
&& pages_reclaimed
< (1 << order
))
2163 static inline struct page
*
2164 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
2165 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2166 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2171 /* Acquire the OOM killer lock for the zones in zonelist */
2172 if (!try_set_zonelist_oom(zonelist
, gfp_mask
)) {
2173 schedule_timeout_uninterruptible(1);
2178 * Go through the zonelist yet one more time, keep very high watermark
2179 * here, this is only to catch a parallel oom killing, we must fail if
2180 * we're still under heavy pressure.
2182 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
,
2183 order
, zonelist
, high_zoneidx
,
2184 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
,
2185 preferred_zone
, migratetype
);
2189 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2190 /* The OOM killer will not help higher order allocs */
2191 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2193 /* The OOM killer does not needlessly kill tasks for lowmem */
2194 if (high_zoneidx
< ZONE_NORMAL
)
2197 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
2198 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
2199 * The caller should handle page allocation failure by itself if
2200 * it specifies __GFP_THISNODE.
2201 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
2203 if (gfp_mask
& __GFP_THISNODE
)
2206 /* Exhausted what can be done so it's blamo time */
2207 out_of_memory(zonelist
, gfp_mask
, order
, nodemask
, false);
2210 clear_zonelist_oom(zonelist
, gfp_mask
);
2214 #ifdef CONFIG_COMPACTION
2215 /* Try memory compaction for high-order allocations before reclaim */
2216 static struct page
*
2217 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2218 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2219 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2220 int migratetype
, enum migrate_mode mode
,
2221 bool *contended_compaction
, bool *deferred_compaction
,
2222 unsigned long *did_some_progress
)
2227 if (compaction_deferred(preferred_zone
, order
)) {
2228 *deferred_compaction
= true;
2232 current
->flags
|= PF_MEMALLOC
;
2233 *did_some_progress
= try_to_compact_pages(zonelist
, order
, gfp_mask
,
2235 contended_compaction
);
2236 current
->flags
&= ~PF_MEMALLOC
;
2238 if (*did_some_progress
!= COMPACT_SKIPPED
) {
2241 /* Page migration frees to the PCP lists but we want merging */
2242 drain_pages(get_cpu());
2245 page
= get_page_from_freelist(gfp_mask
, nodemask
,
2246 order
, zonelist
, high_zoneidx
,
2247 alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2248 preferred_zone
, migratetype
);
2250 preferred_zone
->compact_blockskip_flush
= false;
2251 compaction_defer_reset(preferred_zone
, order
, true);
2252 count_vm_event(COMPACTSUCCESS
);
2257 * It's bad if compaction run occurs and fails.
2258 * The most likely reason is that pages exist,
2259 * but not enough to satisfy watermarks.
2261 count_vm_event(COMPACTFAIL
);
2264 * As async compaction considers a subset of pageblocks, only
2265 * defer if the failure was a sync compaction failure.
2267 if (mode
!= MIGRATE_ASYNC
)
2268 defer_compaction(preferred_zone
, order
);
2276 static inline struct page
*
2277 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2278 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2279 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2280 int migratetype
, enum migrate_mode mode
, bool *contended_compaction
,
2281 bool *deferred_compaction
, unsigned long *did_some_progress
)
2285 #endif /* CONFIG_COMPACTION */
2287 /* Perform direct synchronous page reclaim */
2289 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
, struct zonelist
*zonelist
,
2290 nodemask_t
*nodemask
)
2292 struct reclaim_state reclaim_state
;
2297 /* We now go into synchronous reclaim */
2298 cpuset_memory_pressure_bump();
2299 current
->flags
|= PF_MEMALLOC
;
2300 lockdep_set_current_reclaim_state(gfp_mask
);
2301 reclaim_state
.reclaimed_slab
= 0;
2302 current
->reclaim_state
= &reclaim_state
;
2304 progress
= try_to_free_pages(zonelist
, order
, gfp_mask
, nodemask
);
2306 current
->reclaim_state
= NULL
;
2307 lockdep_clear_current_reclaim_state();
2308 current
->flags
&= ~PF_MEMALLOC
;
2315 /* The really slow allocator path where we enter direct reclaim */
2316 static inline struct page
*
2317 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
2318 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2319 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2320 int migratetype
, unsigned long *did_some_progress
)
2322 struct page
*page
= NULL
;
2323 bool drained
= false;
2325 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, zonelist
,
2327 if (unlikely(!(*did_some_progress
)))
2330 /* After successful reclaim, reconsider all zones for allocation */
2331 if (IS_ENABLED(CONFIG_NUMA
))
2332 zlc_clear_zones_full(zonelist
);
2335 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
2336 zonelist
, high_zoneidx
,
2337 alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2338 preferred_zone
, migratetype
);
2341 * If an allocation failed after direct reclaim, it could be because
2342 * pages are pinned on the per-cpu lists. Drain them and try again
2344 if (!page
&& !drained
) {
2354 * This is called in the allocator slow-path if the allocation request is of
2355 * sufficient urgency to ignore watermarks and take other desperate measures
2357 static inline struct page
*
2358 __alloc_pages_high_priority(gfp_t gfp_mask
, unsigned int order
,
2359 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2360 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2366 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
2367 zonelist
, high_zoneidx
, ALLOC_NO_WATERMARKS
,
2368 preferred_zone
, migratetype
);
2370 if (!page
&& gfp_mask
& __GFP_NOFAIL
)
2371 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2372 } while (!page
&& (gfp_mask
& __GFP_NOFAIL
));
2377 static void reset_alloc_batches(struct zonelist
*zonelist
,
2378 enum zone_type high_zoneidx
,
2379 struct zone
*preferred_zone
)
2384 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
) {
2386 * Only reset the batches of zones that were actually
2387 * considered in the fairness pass, we don't want to
2388 * trash fairness information for zones that are not
2389 * actually part of this zonelist's round-robin cycle.
2391 if (!zone_local(preferred_zone
, zone
))
2393 mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
2394 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
2395 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
2399 static void wake_all_kswapds(unsigned int order
,
2400 struct zonelist
*zonelist
,
2401 enum zone_type high_zoneidx
,
2402 struct zone
*preferred_zone
)
2407 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
)
2408 wakeup_kswapd(zone
, order
, zone_idx(preferred_zone
));
2412 gfp_to_alloc_flags(gfp_t gfp_mask
)
2414 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
2415 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
2417 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2418 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
2421 * The caller may dip into page reserves a bit more if the caller
2422 * cannot run direct reclaim, or if the caller has realtime scheduling
2423 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2424 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
2426 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
2430 * Not worth trying to allocate harder for
2431 * __GFP_NOMEMALLOC even if it can't schedule.
2433 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2434 alloc_flags
|= ALLOC_HARDER
;
2436 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
2437 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
2439 alloc_flags
&= ~ALLOC_CPUSET
;
2440 } else if (unlikely(rt_task(current
)) && !in_interrupt())
2441 alloc_flags
|= ALLOC_HARDER
;
2443 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
2444 if (gfp_mask
& __GFP_MEMALLOC
)
2445 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2446 else if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
2447 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2448 else if (!in_interrupt() &&
2449 ((current
->flags
& PF_MEMALLOC
) ||
2450 unlikely(test_thread_flag(TIF_MEMDIE
))))
2451 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2454 if (allocflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
2455 alloc_flags
|= ALLOC_CMA
;
2460 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
2462 return !!(gfp_to_alloc_flags(gfp_mask
) & ALLOC_NO_WATERMARKS
);
2465 static inline struct page
*
2466 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
2467 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2468 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2471 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
2472 struct page
*page
= NULL
;
2474 unsigned long pages_reclaimed
= 0;
2475 unsigned long did_some_progress
;
2476 enum migrate_mode migration_mode
= MIGRATE_ASYNC
;
2477 bool deferred_compaction
= false;
2478 bool contended_compaction
= false;
2481 * In the slowpath, we sanity check order to avoid ever trying to
2482 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2483 * be using allocators in order of preference for an area that is
2486 if (order
>= MAX_ORDER
) {
2487 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
2492 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
2493 * __GFP_NOWARN set) should not cause reclaim since the subsystem
2494 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
2495 * using a larger set of nodes after it has established that the
2496 * allowed per node queues are empty and that nodes are
2499 if (IS_ENABLED(CONFIG_NUMA
) &&
2500 (gfp_mask
& GFP_THISNODE
) == GFP_THISNODE
)
2504 if (!(gfp_mask
& __GFP_NO_KSWAPD
))
2505 wake_all_kswapds(order
, zonelist
, high_zoneidx
, preferred_zone
);
2508 * OK, we're below the kswapd watermark and have kicked background
2509 * reclaim. Now things get more complex, so set up alloc_flags according
2510 * to how we want to proceed.
2512 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
2515 * Find the true preferred zone if the allocation is unconstrained by
2518 if (!(alloc_flags
& ALLOC_CPUSET
) && !nodemask
)
2519 first_zones_zonelist(zonelist
, high_zoneidx
, NULL
,
2523 /* This is the last chance, in general, before the goto nopage. */
2524 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
, zonelist
,
2525 high_zoneidx
, alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2526 preferred_zone
, migratetype
);
2530 /* Allocate without watermarks if the context allows */
2531 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
2533 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
2534 * the allocation is high priority and these type of
2535 * allocations are system rather than user orientated
2537 zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
2539 page
= __alloc_pages_high_priority(gfp_mask
, order
,
2540 zonelist
, high_zoneidx
, nodemask
,
2541 preferred_zone
, migratetype
);
2547 /* Atomic allocations - we can't balance anything */
2550 * All existing users of the deprecated __GFP_NOFAIL are
2551 * blockable, so warn of any new users that actually allow this
2552 * type of allocation to fail.
2554 WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
);
2558 /* Avoid recursion of direct reclaim */
2559 if (current
->flags
& PF_MEMALLOC
)
2562 /* Avoid allocations with no watermarks from looping endlessly */
2563 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
2567 * Try direct compaction. The first pass is asynchronous. Subsequent
2568 * attempts after direct reclaim are synchronous
2570 page
= __alloc_pages_direct_compact(gfp_mask
, order
, zonelist
,
2571 high_zoneidx
, nodemask
, alloc_flags
,
2572 preferred_zone
, migratetype
,
2573 migration_mode
, &contended_compaction
,
2574 &deferred_compaction
,
2575 &did_some_progress
);
2580 * It can become very expensive to allocate transparent hugepages at
2581 * fault, so use asynchronous memory compaction for THP unless it is
2582 * khugepaged trying to collapse.
2584 if (!(gfp_mask
& __GFP_NO_KSWAPD
) || (current
->flags
& PF_KTHREAD
))
2585 migration_mode
= MIGRATE_SYNC_LIGHT
;
2588 * If compaction is deferred for high-order allocations, it is because
2589 * sync compaction recently failed. In this is the case and the caller
2590 * requested a movable allocation that does not heavily disrupt the
2591 * system then fail the allocation instead of entering direct reclaim.
2593 if ((deferred_compaction
|| contended_compaction
) &&
2594 (gfp_mask
& __GFP_NO_KSWAPD
))
2597 /* Try direct reclaim and then allocating */
2598 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
,
2599 zonelist
, high_zoneidx
,
2601 alloc_flags
, preferred_zone
,
2602 migratetype
, &did_some_progress
);
2607 * If we failed to make any progress reclaiming, then we are
2608 * running out of options and have to consider going OOM
2610 if (!did_some_progress
) {
2611 if (oom_gfp_allowed(gfp_mask
)) {
2612 if (oom_killer_disabled
)
2614 /* Coredumps can quickly deplete all memory reserves */
2615 if ((current
->flags
& PF_DUMPCORE
) &&
2616 !(gfp_mask
& __GFP_NOFAIL
))
2618 page
= __alloc_pages_may_oom(gfp_mask
, order
,
2619 zonelist
, high_zoneidx
,
2620 nodemask
, preferred_zone
,
2625 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2627 * The oom killer is not called for high-order
2628 * allocations that may fail, so if no progress
2629 * is being made, there are no other options and
2630 * retrying is unlikely to help.
2632 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2635 * The oom killer is not called for lowmem
2636 * allocations to prevent needlessly killing
2639 if (high_zoneidx
< ZONE_NORMAL
)
2647 /* Check if we should retry the allocation */
2648 pages_reclaimed
+= did_some_progress
;
2649 if (should_alloc_retry(gfp_mask
, order
, did_some_progress
,
2651 /* Wait for some write requests to complete then retry */
2652 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2656 * High-order allocations do not necessarily loop after
2657 * direct reclaim and reclaim/compaction depends on compaction
2658 * being called after reclaim so call directly if necessary
2660 page
= __alloc_pages_direct_compact(gfp_mask
, order
, zonelist
,
2661 high_zoneidx
, nodemask
, alloc_flags
,
2662 preferred_zone
, migratetype
,
2663 migration_mode
, &contended_compaction
,
2664 &deferred_compaction
,
2665 &did_some_progress
);
2671 warn_alloc_failed(gfp_mask
, order
, NULL
);
2674 if (kmemcheck_enabled
)
2675 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
2681 * This is the 'heart' of the zoned buddy allocator.
2684 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
2685 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
2687 enum zone_type high_zoneidx
= gfp_zone(gfp_mask
);
2688 struct zone
*preferred_zone
;
2689 struct page
*page
= NULL
;
2690 int migratetype
= allocflags_to_migratetype(gfp_mask
);
2691 unsigned int cpuset_mems_cookie
;
2692 int alloc_flags
= ALLOC_WMARK_LOW
|ALLOC_CPUSET
|ALLOC_FAIR
;
2694 gfp_mask
&= gfp_allowed_mask
;
2696 lockdep_trace_alloc(gfp_mask
);
2698 might_sleep_if(gfp_mask
& __GFP_WAIT
);
2700 if (should_fail_alloc_page(gfp_mask
, order
))
2704 * Check the zones suitable for the gfp_mask contain at least one
2705 * valid zone. It's possible to have an empty zonelist as a result
2706 * of GFP_THISNODE and a memoryless node
2708 if (unlikely(!zonelist
->_zonerefs
->zone
))
2712 cpuset_mems_cookie
= read_mems_allowed_begin();
2714 /* The preferred zone is used for statistics later */
2715 first_zones_zonelist(zonelist
, high_zoneidx
,
2716 nodemask
? : &cpuset_current_mems_allowed
,
2718 if (!preferred_zone
)
2722 if (allocflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
2723 alloc_flags
|= ALLOC_CMA
;
2726 /* First allocation attempt */
2727 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
, order
,
2728 zonelist
, high_zoneidx
, alloc_flags
,
2729 preferred_zone
, migratetype
);
2730 if (unlikely(!page
)) {
2732 * The first pass makes sure allocations are spread
2733 * fairly within the local node. However, the local
2734 * node might have free pages left after the fairness
2735 * batches are exhausted, and remote zones haven't
2736 * even been considered yet. Try once more without
2737 * fairness, and include remote zones now, before
2738 * entering the slowpath and waking kswapd: prefer
2739 * spilling to a remote zone over swapping locally.
2741 if (alloc_flags
& ALLOC_FAIR
) {
2742 reset_alloc_batches(zonelist
, high_zoneidx
,
2744 alloc_flags
&= ~ALLOC_FAIR
;
2748 * Runtime PM, block IO and its error handling path
2749 * can deadlock because I/O on the device might not
2752 gfp_mask
= memalloc_noio_flags(gfp_mask
);
2753 page
= __alloc_pages_slowpath(gfp_mask
, order
,
2754 zonelist
, high_zoneidx
, nodemask
,
2755 preferred_zone
, migratetype
);
2758 trace_mm_page_alloc(page
, order
, gfp_mask
, migratetype
);
2762 * When updating a task's mems_allowed, it is possible to race with
2763 * parallel threads in such a way that an allocation can fail while
2764 * the mask is being updated. If a page allocation is about to fail,
2765 * check if the cpuset changed during allocation and if so, retry.
2767 if (unlikely(!page
&& read_mems_allowed_retry(cpuset_mems_cookie
)))
2772 EXPORT_SYMBOL(__alloc_pages_nodemask
);
2775 * Common helper functions.
2777 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
2782 * __get_free_pages() returns a 32-bit address, which cannot represent
2785 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
2787 page
= alloc_pages(gfp_mask
, order
);
2790 return (unsigned long) page_address(page
);
2792 EXPORT_SYMBOL(__get_free_pages
);
2794 unsigned long get_zeroed_page(gfp_t gfp_mask
)
2796 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
2798 EXPORT_SYMBOL(get_zeroed_page
);
2800 void __free_pages(struct page
*page
, unsigned int order
)
2802 if (put_page_testzero(page
)) {
2804 free_hot_cold_page(page
, 0);
2806 __free_pages_ok(page
, order
);
2810 EXPORT_SYMBOL(__free_pages
);
2812 void free_pages(unsigned long addr
, unsigned int order
)
2815 VM_BUG_ON(!virt_addr_valid((void *)addr
));
2816 __free_pages(virt_to_page((void *)addr
), order
);
2820 EXPORT_SYMBOL(free_pages
);
2823 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
2824 * of the current memory cgroup.
2826 * It should be used when the caller would like to use kmalloc, but since the
2827 * allocation is large, it has to fall back to the page allocator.
2829 struct page
*alloc_kmem_pages(gfp_t gfp_mask
, unsigned int order
)
2832 struct mem_cgroup
*memcg
= NULL
;
2834 if (!memcg_kmem_newpage_charge(gfp_mask
, &memcg
, order
))
2836 page
= alloc_pages(gfp_mask
, order
);
2837 memcg_kmem_commit_charge(page
, memcg
, order
);
2841 struct page
*alloc_kmem_pages_node(int nid
, gfp_t gfp_mask
, unsigned int order
)
2844 struct mem_cgroup
*memcg
= NULL
;
2846 if (!memcg_kmem_newpage_charge(gfp_mask
, &memcg
, order
))
2848 page
= alloc_pages_node(nid
, gfp_mask
, order
);
2849 memcg_kmem_commit_charge(page
, memcg
, order
);
2854 * __free_kmem_pages and free_kmem_pages will free pages allocated with
2857 void __free_kmem_pages(struct page
*page
, unsigned int order
)
2859 memcg_kmem_uncharge_pages(page
, order
);
2860 __free_pages(page
, order
);
2863 void free_kmem_pages(unsigned long addr
, unsigned int order
)
2866 VM_BUG_ON(!virt_addr_valid((void *)addr
));
2867 __free_kmem_pages(virt_to_page((void *)addr
), order
);
2871 static void *make_alloc_exact(unsigned long addr
, unsigned order
, size_t size
)
2874 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
2875 unsigned long used
= addr
+ PAGE_ALIGN(size
);
2877 split_page(virt_to_page((void *)addr
), order
);
2878 while (used
< alloc_end
) {
2883 return (void *)addr
;
2887 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2888 * @size: the number of bytes to allocate
2889 * @gfp_mask: GFP flags for the allocation
2891 * This function is similar to alloc_pages(), except that it allocates the
2892 * minimum number of pages to satisfy the request. alloc_pages() can only
2893 * allocate memory in power-of-two pages.
2895 * This function is also limited by MAX_ORDER.
2897 * Memory allocated by this function must be released by free_pages_exact().
2899 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
2901 unsigned int order
= get_order(size
);
2904 addr
= __get_free_pages(gfp_mask
, order
);
2905 return make_alloc_exact(addr
, order
, size
);
2907 EXPORT_SYMBOL(alloc_pages_exact
);
2910 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
2912 * @nid: the preferred node ID where memory should be allocated
2913 * @size: the number of bytes to allocate
2914 * @gfp_mask: GFP flags for the allocation
2916 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
2918 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
2921 void *alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
2923 unsigned order
= get_order(size
);
2924 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
2927 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
2929 EXPORT_SYMBOL(alloc_pages_exact_nid
);
2932 * free_pages_exact - release memory allocated via alloc_pages_exact()
2933 * @virt: the value returned by alloc_pages_exact.
2934 * @size: size of allocation, same value as passed to alloc_pages_exact().
2936 * Release the memory allocated by a previous call to alloc_pages_exact.
2938 void free_pages_exact(void *virt
, size_t size
)
2940 unsigned long addr
= (unsigned long)virt
;
2941 unsigned long end
= addr
+ PAGE_ALIGN(size
);
2943 while (addr
< end
) {
2948 EXPORT_SYMBOL(free_pages_exact
);
2951 * nr_free_zone_pages - count number of pages beyond high watermark
2952 * @offset: The zone index of the highest zone
2954 * nr_free_zone_pages() counts the number of counts pages which are beyond the
2955 * high watermark within all zones at or below a given zone index. For each
2956 * zone, the number of pages is calculated as:
2957 * managed_pages - high_pages
2959 static unsigned long nr_free_zone_pages(int offset
)
2964 /* Just pick one node, since fallback list is circular */
2965 unsigned long sum
= 0;
2967 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
2969 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
2970 unsigned long size
= zone
->managed_pages
;
2971 unsigned long high
= high_wmark_pages(zone
);
2980 * nr_free_buffer_pages - count number of pages beyond high watermark
2982 * nr_free_buffer_pages() counts the number of pages which are beyond the high
2983 * watermark within ZONE_DMA and ZONE_NORMAL.
2985 unsigned long nr_free_buffer_pages(void)
2987 return nr_free_zone_pages(gfp_zone(GFP_USER
));
2989 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
2992 * nr_free_pagecache_pages - count number of pages beyond high watermark
2994 * nr_free_pagecache_pages() counts the number of pages which are beyond the
2995 * high watermark within all zones.
2997 unsigned long nr_free_pagecache_pages(void)
2999 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
3002 static inline void show_node(struct zone
*zone
)
3004 if (IS_ENABLED(CONFIG_NUMA
))
3005 printk("Node %d ", zone_to_nid(zone
));
3008 void si_meminfo(struct sysinfo
*val
)
3010 val
->totalram
= totalram_pages
;
3012 val
->freeram
= global_page_state(NR_FREE_PAGES
);
3013 val
->bufferram
= nr_blockdev_pages();
3014 val
->totalhigh
= totalhigh_pages
;
3015 val
->freehigh
= nr_free_highpages();
3016 val
->mem_unit
= PAGE_SIZE
;
3019 EXPORT_SYMBOL(si_meminfo
);
3022 void si_meminfo_node(struct sysinfo
*val
, int nid
)
3024 int zone_type
; /* needs to be signed */
3025 unsigned long managed_pages
= 0;
3026 pg_data_t
*pgdat
= NODE_DATA(nid
);
3028 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
3029 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
3030 val
->totalram
= managed_pages
;
3031 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
3032 #ifdef CONFIG_HIGHMEM
3033 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].managed_pages
;
3034 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
3040 val
->mem_unit
= PAGE_SIZE
;
3045 * Determine whether the node should be displayed or not, depending on whether
3046 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3048 bool skip_free_areas_node(unsigned int flags
, int nid
)
3051 unsigned int cpuset_mems_cookie
;
3053 if (!(flags
& SHOW_MEM_FILTER_NODES
))
3057 cpuset_mems_cookie
= read_mems_allowed_begin();
3058 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
3059 } while (read_mems_allowed_retry(cpuset_mems_cookie
));
3064 #define K(x) ((x) << (PAGE_SHIFT-10))
3066 static void show_migration_types(unsigned char type
)
3068 static const char types
[MIGRATE_TYPES
] = {
3069 [MIGRATE_UNMOVABLE
] = 'U',
3070 [MIGRATE_RECLAIMABLE
] = 'E',
3071 [MIGRATE_MOVABLE
] = 'M',
3072 [MIGRATE_RESERVE
] = 'R',
3074 [MIGRATE_CMA
] = 'C',
3076 #ifdef CONFIG_MEMORY_ISOLATION
3077 [MIGRATE_ISOLATE
] = 'I',
3080 char tmp
[MIGRATE_TYPES
+ 1];
3084 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
3085 if (type
& (1 << i
))
3090 printk("(%s) ", tmp
);
3094 * Show free area list (used inside shift_scroll-lock stuff)
3095 * We also calculate the percentage fragmentation. We do this by counting the
3096 * memory on each free list with the exception of the first item on the list.
3097 * Suppresses nodes that are not allowed by current's cpuset if
3098 * SHOW_MEM_FILTER_NODES is passed.
3100 void show_free_areas(unsigned int filter
)
3105 for_each_populated_zone(zone
) {
3106 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3109 printk("%s per-cpu:\n", zone
->name
);
3111 for_each_online_cpu(cpu
) {
3112 struct per_cpu_pageset
*pageset
;
3114 pageset
= per_cpu_ptr(zone
->pageset
, cpu
);
3116 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
3117 cpu
, pageset
->pcp
.high
,
3118 pageset
->pcp
.batch
, pageset
->pcp
.count
);
3122 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3123 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3125 " dirty:%lu writeback:%lu unstable:%lu\n"
3126 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3127 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3129 global_page_state(NR_ACTIVE_ANON
),
3130 global_page_state(NR_INACTIVE_ANON
),
3131 global_page_state(NR_ISOLATED_ANON
),
3132 global_page_state(NR_ACTIVE_FILE
),
3133 global_page_state(NR_INACTIVE_FILE
),
3134 global_page_state(NR_ISOLATED_FILE
),
3135 global_page_state(NR_UNEVICTABLE
),
3136 global_page_state(NR_FILE_DIRTY
),
3137 global_page_state(NR_WRITEBACK
),
3138 global_page_state(NR_UNSTABLE_NFS
),
3139 global_page_state(NR_FREE_PAGES
),
3140 global_page_state(NR_SLAB_RECLAIMABLE
),
3141 global_page_state(NR_SLAB_UNRECLAIMABLE
),
3142 global_page_state(NR_FILE_MAPPED
),
3143 global_page_state(NR_SHMEM
),
3144 global_page_state(NR_PAGETABLE
),
3145 global_page_state(NR_BOUNCE
),
3146 global_page_state(NR_FREE_CMA_PAGES
));
3148 for_each_populated_zone(zone
) {
3151 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3159 " active_anon:%lukB"
3160 " inactive_anon:%lukB"
3161 " active_file:%lukB"
3162 " inactive_file:%lukB"
3163 " unevictable:%lukB"
3164 " isolated(anon):%lukB"
3165 " isolated(file):%lukB"
3173 " slab_reclaimable:%lukB"
3174 " slab_unreclaimable:%lukB"
3175 " kernel_stack:%lukB"
3180 " writeback_tmp:%lukB"
3181 " pages_scanned:%lu"
3182 " all_unreclaimable? %s"
3185 K(zone_page_state(zone
, NR_FREE_PAGES
)),
3186 K(min_wmark_pages(zone
)),
3187 K(low_wmark_pages(zone
)),
3188 K(high_wmark_pages(zone
)),
3189 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
3190 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
3191 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
3192 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
3193 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
3194 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
3195 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
3196 K(zone
->present_pages
),
3197 K(zone
->managed_pages
),
3198 K(zone_page_state(zone
, NR_MLOCK
)),
3199 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
3200 K(zone_page_state(zone
, NR_WRITEBACK
)),
3201 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
3202 K(zone_page_state(zone
, NR_SHMEM
)),
3203 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
3204 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
3205 zone_page_state(zone
, NR_KERNEL_STACK
) *
3207 K(zone_page_state(zone
, NR_PAGETABLE
)),
3208 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
3209 K(zone_page_state(zone
, NR_BOUNCE
)),
3210 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)),
3211 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
3212 zone
->pages_scanned
,
3213 (!zone_reclaimable(zone
) ? "yes" : "no")
3215 printk("lowmem_reserve[]:");
3216 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3217 printk(" %lu", zone
->lowmem_reserve
[i
]);
3221 for_each_populated_zone(zone
) {
3222 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
3223 unsigned char types
[MAX_ORDER
];
3225 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3228 printk("%s: ", zone
->name
);
3230 spin_lock_irqsave(&zone
->lock
, flags
);
3231 for (order
= 0; order
< MAX_ORDER
; order
++) {
3232 struct free_area
*area
= &zone
->free_area
[order
];
3235 nr
[order
] = area
->nr_free
;
3236 total
+= nr
[order
] << order
;
3239 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
3240 if (!list_empty(&area
->free_list
[type
]))
3241 types
[order
] |= 1 << type
;
3244 spin_unlock_irqrestore(&zone
->lock
, flags
);
3245 for (order
= 0; order
< MAX_ORDER
; order
++) {
3246 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
3248 show_migration_types(types
[order
]);
3250 printk("= %lukB\n", K(total
));
3253 hugetlb_show_meminfo();
3255 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
3257 show_swap_cache_info();
3260 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
3262 zoneref
->zone
= zone
;
3263 zoneref
->zone_idx
= zone_idx(zone
);
3267 * Builds allocation fallback zone lists.
3269 * Add all populated zones of a node to the zonelist.
3271 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
3275 enum zone_type zone_type
= MAX_NR_ZONES
;
3279 zone
= pgdat
->node_zones
+ zone_type
;
3280 if (populated_zone(zone
)) {
3281 zoneref_set_zone(zone
,
3282 &zonelist
->_zonerefs
[nr_zones
++]);
3283 check_highest_zone(zone_type
);
3285 } while (zone_type
);
3293 * 0 = automatic detection of better ordering.
3294 * 1 = order by ([node] distance, -zonetype)
3295 * 2 = order by (-zonetype, [node] distance)
3297 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
3298 * the same zonelist. So only NUMA can configure this param.
3300 #define ZONELIST_ORDER_DEFAULT 0
3301 #define ZONELIST_ORDER_NODE 1
3302 #define ZONELIST_ORDER_ZONE 2
3304 /* zonelist order in the kernel.
3305 * set_zonelist_order() will set this to NODE or ZONE.
3307 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3308 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
3312 /* The value user specified ....changed by config */
3313 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3314 /* string for sysctl */
3315 #define NUMA_ZONELIST_ORDER_LEN 16
3316 char numa_zonelist_order
[16] = "default";
3319 * interface for configure zonelist ordering.
3320 * command line option "numa_zonelist_order"
3321 * = "[dD]efault - default, automatic configuration.
3322 * = "[nN]ode - order by node locality, then by zone within node
3323 * = "[zZ]one - order by zone, then by locality within zone
3326 static int __parse_numa_zonelist_order(char *s
)
3328 if (*s
== 'd' || *s
== 'D') {
3329 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3330 } else if (*s
== 'n' || *s
== 'N') {
3331 user_zonelist_order
= ZONELIST_ORDER_NODE
;
3332 } else if (*s
== 'z' || *s
== 'Z') {
3333 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
3336 "Ignoring invalid numa_zonelist_order value: "
3343 static __init
int setup_numa_zonelist_order(char *s
)
3350 ret
= __parse_numa_zonelist_order(s
);
3352 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
3356 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
3359 * sysctl handler for numa_zonelist_order
3361 int numa_zonelist_order_handler(ctl_table
*table
, int write
,
3362 void __user
*buffer
, size_t *length
,
3365 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
3367 static DEFINE_MUTEX(zl_order_mutex
);
3369 mutex_lock(&zl_order_mutex
);
3371 if (strlen((char *)table
->data
) >= NUMA_ZONELIST_ORDER_LEN
) {
3375 strcpy(saved_string
, (char *)table
->data
);
3377 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
3381 int oldval
= user_zonelist_order
;
3383 ret
= __parse_numa_zonelist_order((char *)table
->data
);
3386 * bogus value. restore saved string
3388 strncpy((char *)table
->data
, saved_string
,
3389 NUMA_ZONELIST_ORDER_LEN
);
3390 user_zonelist_order
= oldval
;
3391 } else if (oldval
!= user_zonelist_order
) {
3392 mutex_lock(&zonelists_mutex
);
3393 build_all_zonelists(NULL
, NULL
);
3394 mutex_unlock(&zonelists_mutex
);
3398 mutex_unlock(&zl_order_mutex
);
3403 #define MAX_NODE_LOAD (nr_online_nodes)
3404 static int node_load
[MAX_NUMNODES
];
3407 * find_next_best_node - find the next node that should appear in a given node's fallback list
3408 * @node: node whose fallback list we're appending
3409 * @used_node_mask: nodemask_t of already used nodes
3411 * We use a number of factors to determine which is the next node that should
3412 * appear on a given node's fallback list. The node should not have appeared
3413 * already in @node's fallback list, and it should be the next closest node
3414 * according to the distance array (which contains arbitrary distance values
3415 * from each node to each node in the system), and should also prefer nodes
3416 * with no CPUs, since presumably they'll have very little allocation pressure
3417 * on them otherwise.
3418 * It returns -1 if no node is found.
3420 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
3423 int min_val
= INT_MAX
;
3424 int best_node
= NUMA_NO_NODE
;
3425 const struct cpumask
*tmp
= cpumask_of_node(0);
3427 /* Use the local node if we haven't already */
3428 if (!node_isset(node
, *used_node_mask
)) {
3429 node_set(node
, *used_node_mask
);
3433 for_each_node_state(n
, N_MEMORY
) {
3435 /* Don't want a node to appear more than once */
3436 if (node_isset(n
, *used_node_mask
))
3439 /* Use the distance array to find the distance */
3440 val
= node_distance(node
, n
);
3442 /* Penalize nodes under us ("prefer the next node") */
3445 /* Give preference to headless and unused nodes */
3446 tmp
= cpumask_of_node(n
);
3447 if (!cpumask_empty(tmp
))
3448 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
3450 /* Slight preference for less loaded node */
3451 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
3452 val
+= node_load
[n
];
3454 if (val
< min_val
) {
3461 node_set(best_node
, *used_node_mask
);
3468 * Build zonelists ordered by node and zones within node.
3469 * This results in maximum locality--normal zone overflows into local
3470 * DMA zone, if any--but risks exhausting DMA zone.
3472 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
3475 struct zonelist
*zonelist
;
3477 zonelist
= &pgdat
->node_zonelists
[0];
3478 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
3480 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
3481 zonelist
->_zonerefs
[j
].zone
= NULL
;
3482 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3486 * Build gfp_thisnode zonelists
3488 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
3491 struct zonelist
*zonelist
;
3493 zonelist
= &pgdat
->node_zonelists
[1];
3494 j
= build_zonelists_node(pgdat
, zonelist
, 0);
3495 zonelist
->_zonerefs
[j
].zone
= NULL
;
3496 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3500 * Build zonelists ordered by zone and nodes within zones.
3501 * This results in conserving DMA zone[s] until all Normal memory is
3502 * exhausted, but results in overflowing to remote node while memory
3503 * may still exist in local DMA zone.
3505 static int node_order
[MAX_NUMNODES
];
3507 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
3510 int zone_type
; /* needs to be signed */
3512 struct zonelist
*zonelist
;
3514 zonelist
= &pgdat
->node_zonelists
[0];
3516 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
3517 for (j
= 0; j
< nr_nodes
; j
++) {
3518 node
= node_order
[j
];
3519 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
3520 if (populated_zone(z
)) {
3522 &zonelist
->_zonerefs
[pos
++]);
3523 check_highest_zone(zone_type
);
3527 zonelist
->_zonerefs
[pos
].zone
= NULL
;
3528 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
3531 static int default_zonelist_order(void)
3534 unsigned long low_kmem_size
, total_size
;
3538 * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
3539 * If they are really small and used heavily, the system can fall
3540 * into OOM very easily.
3541 * This function detect ZONE_DMA/DMA32 size and configures zone order.
3543 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
3546 for_each_online_node(nid
) {
3547 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
3548 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
3549 if (populated_zone(z
)) {
3550 if (zone_type
< ZONE_NORMAL
)
3551 low_kmem_size
+= z
->managed_pages
;
3552 total_size
+= z
->managed_pages
;
3553 } else if (zone_type
== ZONE_NORMAL
) {
3555 * If any node has only lowmem, then node order
3556 * is preferred to allow kernel allocations
3557 * locally; otherwise, they can easily infringe
3558 * on other nodes when there is an abundance of
3559 * lowmem available to allocate from.
3561 return ZONELIST_ORDER_NODE
;
3565 if (!low_kmem_size
|| /* there are no DMA area. */
3566 low_kmem_size
> total_size
/2) /* DMA/DMA32 is big. */
3567 return ZONELIST_ORDER_NODE
;
3569 * look into each node's config.
3570 * If there is a node whose DMA/DMA32 memory is very big area on
3571 * local memory, NODE_ORDER may be suitable.
3573 average_size
= total_size
/
3574 (nodes_weight(node_states
[N_MEMORY
]) + 1);
3575 for_each_online_node(nid
) {
3578 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
3579 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
3580 if (populated_zone(z
)) {
3581 if (zone_type
< ZONE_NORMAL
)
3582 low_kmem_size
+= z
->present_pages
;
3583 total_size
+= z
->present_pages
;
3586 if (low_kmem_size
&&
3587 total_size
> average_size
&& /* ignore small node */
3588 low_kmem_size
> total_size
* 70/100)
3589 return ZONELIST_ORDER_NODE
;
3591 return ZONELIST_ORDER_ZONE
;
3594 static void set_zonelist_order(void)
3596 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
3597 current_zonelist_order
= default_zonelist_order();
3599 current_zonelist_order
= user_zonelist_order
;
3602 static void build_zonelists(pg_data_t
*pgdat
)
3606 nodemask_t used_mask
;
3607 int local_node
, prev_node
;
3608 struct zonelist
*zonelist
;
3609 int order
= current_zonelist_order
;
3611 /* initialize zonelists */
3612 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
3613 zonelist
= pgdat
->node_zonelists
+ i
;
3614 zonelist
->_zonerefs
[0].zone
= NULL
;
3615 zonelist
->_zonerefs
[0].zone_idx
= 0;
3618 /* NUMA-aware ordering of nodes */
3619 local_node
= pgdat
->node_id
;
3620 load
= nr_online_nodes
;
3621 prev_node
= local_node
;
3622 nodes_clear(used_mask
);
3624 memset(node_order
, 0, sizeof(node_order
));
3627 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
3629 * We don't want to pressure a particular node.
3630 * So adding penalty to the first node in same
3631 * distance group to make it round-robin.
3633 if (node_distance(local_node
, node
) !=
3634 node_distance(local_node
, prev_node
))
3635 node_load
[node
] = load
;
3639 if (order
== ZONELIST_ORDER_NODE
)
3640 build_zonelists_in_node_order(pgdat
, node
);
3642 node_order
[j
++] = node
; /* remember order */
3645 if (order
== ZONELIST_ORDER_ZONE
) {
3646 /* calculate node order -- i.e., DMA last! */
3647 build_zonelists_in_zone_order(pgdat
, j
);
3650 build_thisnode_zonelists(pgdat
);
3653 /* Construct the zonelist performance cache - see further mmzone.h */
3654 static void build_zonelist_cache(pg_data_t
*pgdat
)
3656 struct zonelist
*zonelist
;
3657 struct zonelist_cache
*zlc
;
3660 zonelist
= &pgdat
->node_zonelists
[0];
3661 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
3662 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
3663 for (z
= zonelist
->_zonerefs
; z
->zone
; z
++)
3664 zlc
->z_to_n
[z
- zonelist
->_zonerefs
] = zonelist_node_idx(z
);
3667 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3669 * Return node id of node used for "local" allocations.
3670 * I.e., first node id of first zone in arg node's generic zonelist.
3671 * Used for initializing percpu 'numa_mem', which is used primarily
3672 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
3674 int local_memory_node(int node
)
3678 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
3679 gfp_zone(GFP_KERNEL
),
3686 #else /* CONFIG_NUMA */
3688 static void set_zonelist_order(void)
3690 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
3693 static void build_zonelists(pg_data_t
*pgdat
)
3695 int node
, local_node
;
3697 struct zonelist
*zonelist
;
3699 local_node
= pgdat
->node_id
;
3701 zonelist
= &pgdat
->node_zonelists
[0];
3702 j
= build_zonelists_node(pgdat
, zonelist
, 0);
3705 * Now we build the zonelist so that it contains the zones
3706 * of all the other nodes.
3707 * We don't want to pressure a particular node, so when
3708 * building the zones for node N, we make sure that the
3709 * zones coming right after the local ones are those from
3710 * node N+1 (modulo N)
3712 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
3713 if (!node_online(node
))
3715 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
3717 for (node
= 0; node
< local_node
; node
++) {
3718 if (!node_online(node
))
3720 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
3723 zonelist
->_zonerefs
[j
].zone
= NULL
;
3724 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3727 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3728 static void build_zonelist_cache(pg_data_t
*pgdat
)
3730 pgdat
->node_zonelists
[0].zlcache_ptr
= NULL
;
3733 #endif /* CONFIG_NUMA */
3736 * Boot pageset table. One per cpu which is going to be used for all
3737 * zones and all nodes. The parameters will be set in such a way
3738 * that an item put on a list will immediately be handed over to
3739 * the buddy list. This is safe since pageset manipulation is done
3740 * with interrupts disabled.
3742 * The boot_pagesets must be kept even after bootup is complete for
3743 * unused processors and/or zones. They do play a role for bootstrapping
3744 * hotplugged processors.
3746 * zoneinfo_show() and maybe other functions do
3747 * not check if the processor is online before following the pageset pointer.
3748 * Other parts of the kernel may not check if the zone is available.
3750 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
3751 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
3752 static void setup_zone_pageset(struct zone
*zone
);
3755 * Global mutex to protect against size modification of zonelists
3756 * as well as to serialize pageset setup for the new populated zone.
3758 DEFINE_MUTEX(zonelists_mutex
);
3760 /* return values int ....just for stop_machine() */
3761 static int __build_all_zonelists(void *data
)
3765 pg_data_t
*self
= data
;
3768 memset(node_load
, 0, sizeof(node_load
));
3771 if (self
&& !node_online(self
->node_id
)) {
3772 build_zonelists(self
);
3773 build_zonelist_cache(self
);
3776 for_each_online_node(nid
) {
3777 pg_data_t
*pgdat
= NODE_DATA(nid
);
3779 build_zonelists(pgdat
);
3780 build_zonelist_cache(pgdat
);
3784 * Initialize the boot_pagesets that are going to be used
3785 * for bootstrapping processors. The real pagesets for
3786 * each zone will be allocated later when the per cpu
3787 * allocator is available.
3789 * boot_pagesets are used also for bootstrapping offline
3790 * cpus if the system is already booted because the pagesets
3791 * are needed to initialize allocators on a specific cpu too.
3792 * F.e. the percpu allocator needs the page allocator which
3793 * needs the percpu allocator in order to allocate its pagesets
3794 * (a chicken-egg dilemma).
3796 for_each_possible_cpu(cpu
) {
3797 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
3799 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3801 * We now know the "local memory node" for each node--
3802 * i.e., the node of the first zone in the generic zonelist.
3803 * Set up numa_mem percpu variable for on-line cpus. During
3804 * boot, only the boot cpu should be on-line; we'll init the
3805 * secondary cpus' numa_mem as they come on-line. During
3806 * node/memory hotplug, we'll fixup all on-line cpus.
3808 if (cpu_online(cpu
))
3809 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
3817 * Called with zonelists_mutex held always
3818 * unless system_state == SYSTEM_BOOTING.
3820 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
3822 set_zonelist_order();
3824 if (system_state
== SYSTEM_BOOTING
) {
3825 __build_all_zonelists(NULL
);
3826 mminit_verify_zonelist();
3827 cpuset_init_current_mems_allowed();
3829 #ifdef CONFIG_MEMORY_HOTPLUG
3831 setup_zone_pageset(zone
);
3833 /* we have to stop all cpus to guarantee there is no user
3835 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
3836 /* cpuset refresh routine should be here */
3838 vm_total_pages
= nr_free_pagecache_pages();
3840 * Disable grouping by mobility if the number of pages in the
3841 * system is too low to allow the mechanism to work. It would be
3842 * more accurate, but expensive to check per-zone. This check is
3843 * made on memory-hotadd so a system can start with mobility
3844 * disabled and enable it later
3846 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
3847 page_group_by_mobility_disabled
= 1;
3849 page_group_by_mobility_disabled
= 0;
3851 printk("Built %i zonelists in %s order, mobility grouping %s. "
3852 "Total pages: %ld\n",
3854 zonelist_order_name
[current_zonelist_order
],
3855 page_group_by_mobility_disabled
? "off" : "on",
3858 printk("Policy zone: %s\n", zone_names
[policy_zone
]);
3863 * Helper functions to size the waitqueue hash table.
3864 * Essentially these want to choose hash table sizes sufficiently
3865 * large so that collisions trying to wait on pages are rare.
3866 * But in fact, the number of active page waitqueues on typical
3867 * systems is ridiculously low, less than 200. So this is even
3868 * conservative, even though it seems large.
3870 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
3871 * waitqueues, i.e. the size of the waitq table given the number of pages.
3873 #define PAGES_PER_WAITQUEUE 256
3875 #ifndef CONFIG_MEMORY_HOTPLUG
3876 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3878 unsigned long size
= 1;
3880 pages
/= PAGES_PER_WAITQUEUE
;
3882 while (size
< pages
)
3886 * Once we have dozens or even hundreds of threads sleeping
3887 * on IO we've got bigger problems than wait queue collision.
3888 * Limit the size of the wait table to a reasonable size.
3890 size
= min(size
, 4096UL);
3892 return max(size
, 4UL);
3896 * A zone's size might be changed by hot-add, so it is not possible to determine
3897 * a suitable size for its wait_table. So we use the maximum size now.
3899 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
3901 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
3902 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
3903 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
3905 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
3906 * or more by the traditional way. (See above). It equals:
3908 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
3909 * ia64(16K page size) : = ( 8G + 4M)byte.
3910 * powerpc (64K page size) : = (32G +16M)byte.
3912 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3919 * This is an integer logarithm so that shifts can be used later
3920 * to extract the more random high bits from the multiplicative
3921 * hash function before the remainder is taken.
3923 static inline unsigned long wait_table_bits(unsigned long size
)
3929 * Check if a pageblock contains reserved pages
3931 static int pageblock_is_reserved(unsigned long start_pfn
, unsigned long end_pfn
)
3935 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
3936 if (!pfn_valid_within(pfn
) || PageReserved(pfn_to_page(pfn
)))
3943 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3944 * of blocks reserved is based on min_wmark_pages(zone). The memory within
3945 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
3946 * higher will lead to a bigger reserve which will get freed as contiguous
3947 * blocks as reclaim kicks in
3949 static void setup_zone_migrate_reserve(struct zone
*zone
)
3951 unsigned long start_pfn
, pfn
, end_pfn
, block_end_pfn
;
3953 unsigned long block_migratetype
;
3958 * Get the start pfn, end pfn and the number of blocks to reserve
3959 * We have to be careful to be aligned to pageblock_nr_pages to
3960 * make sure that we always check pfn_valid for the first page in
3963 start_pfn
= zone
->zone_start_pfn
;
3964 end_pfn
= zone_end_pfn(zone
);
3965 start_pfn
= roundup(start_pfn
, pageblock_nr_pages
);
3966 reserve
= roundup(min_wmark_pages(zone
), pageblock_nr_pages
) >>
3970 * Reserve blocks are generally in place to help high-order atomic
3971 * allocations that are short-lived. A min_free_kbytes value that
3972 * would result in more than 2 reserve blocks for atomic allocations
3973 * is assumed to be in place to help anti-fragmentation for the
3974 * future allocation of hugepages at runtime.
3976 reserve
= min(2, reserve
);
3977 old_reserve
= zone
->nr_migrate_reserve_block
;
3979 /* When memory hot-add, we almost always need to do nothing */
3980 if (reserve
== old_reserve
)
3982 zone
->nr_migrate_reserve_block
= reserve
;
3984 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
3985 if (!pfn_valid(pfn
))
3987 page
= pfn_to_page(pfn
);
3989 /* Watch out for overlapping nodes */
3990 if (page_to_nid(page
) != zone_to_nid(zone
))
3993 block_migratetype
= get_pageblock_migratetype(page
);
3995 /* Only test what is necessary when the reserves are not met */
3998 * Blocks with reserved pages will never free, skip
4001 block_end_pfn
= min(pfn
+ pageblock_nr_pages
, end_pfn
);
4002 if (pageblock_is_reserved(pfn
, block_end_pfn
))
4005 /* If this block is reserved, account for it */
4006 if (block_migratetype
== MIGRATE_RESERVE
) {
4011 /* Suitable for reserving if this block is movable */
4012 if (block_migratetype
== MIGRATE_MOVABLE
) {
4013 set_pageblock_migratetype(page
,
4015 move_freepages_block(zone
, page
,
4020 } else if (!old_reserve
) {
4022 * At boot time we don't need to scan the whole zone
4023 * for turning off MIGRATE_RESERVE.
4029 * If the reserve is met and this is a previous reserved block,
4032 if (block_migratetype
== MIGRATE_RESERVE
) {
4033 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4034 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
4040 * Initially all pages are reserved - free ones are freed
4041 * up by free_all_bootmem() once the early boot process is
4042 * done. Non-atomic initialization, single-pass.
4044 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
4045 unsigned long start_pfn
, enum memmap_context context
)
4048 unsigned long end_pfn
= start_pfn
+ size
;
4052 if (highest_memmap_pfn
< end_pfn
- 1)
4053 highest_memmap_pfn
= end_pfn
- 1;
4055 z
= &NODE_DATA(nid
)->node_zones
[zone
];
4056 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
4058 * There can be holes in boot-time mem_map[]s
4059 * handed to this function. They do not
4060 * exist on hotplugged memory.
4062 if (context
== MEMMAP_EARLY
) {
4063 if (!early_pfn_valid(pfn
))
4065 if (!early_pfn_in_nid(pfn
, nid
))
4068 page
= pfn_to_page(pfn
);
4069 set_page_links(page
, zone
, nid
, pfn
);
4070 mminit_verify_page_links(page
, zone
, nid
, pfn
);
4071 init_page_count(page
);
4072 page_mapcount_reset(page
);
4073 page_cpupid_reset_last(page
);
4074 SetPageReserved(page
);
4076 * Mark the block movable so that blocks are reserved for
4077 * movable at startup. This will force kernel allocations
4078 * to reserve their blocks rather than leaking throughout
4079 * the address space during boot when many long-lived
4080 * kernel allocations are made. Later some blocks near
4081 * the start are marked MIGRATE_RESERVE by
4082 * setup_zone_migrate_reserve()
4084 * bitmap is created for zone's valid pfn range. but memmap
4085 * can be created for invalid pages (for alignment)
4086 * check here not to call set_pageblock_migratetype() against
4089 if ((z
->zone_start_pfn
<= pfn
)
4090 && (pfn
< zone_end_pfn(z
))
4091 && !(pfn
& (pageblock_nr_pages
- 1)))
4092 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4094 INIT_LIST_HEAD(&page
->lru
);
4095 #ifdef WANT_PAGE_VIRTUAL
4096 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
4097 if (!is_highmem_idx(zone
))
4098 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
4103 static void __meminit
zone_init_free_lists(struct zone
*zone
)
4106 for_each_migratetype_order(order
, t
) {
4107 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
4108 zone
->free_area
[order
].nr_free
= 0;
4112 #ifndef __HAVE_ARCH_MEMMAP_INIT
4113 #define memmap_init(size, nid, zone, start_pfn) \
4114 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4117 static int __meminit
zone_batchsize(struct zone
*zone
)
4123 * The per-cpu-pages pools are set to around 1000th of the
4124 * size of the zone. But no more than 1/2 of a meg.
4126 * OK, so we don't know how big the cache is. So guess.
4128 batch
= zone
->managed_pages
/ 1024;
4129 if (batch
* PAGE_SIZE
> 512 * 1024)
4130 batch
= (512 * 1024) / PAGE_SIZE
;
4131 batch
/= 4; /* We effectively *= 4 below */
4136 * Clamp the batch to a 2^n - 1 value. Having a power
4137 * of 2 value was found to be more likely to have
4138 * suboptimal cache aliasing properties in some cases.
4140 * For example if 2 tasks are alternately allocating
4141 * batches of pages, one task can end up with a lot
4142 * of pages of one half of the possible page colors
4143 * and the other with pages of the other colors.
4145 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
4150 /* The deferral and batching of frees should be suppressed under NOMMU
4153 * The problem is that NOMMU needs to be able to allocate large chunks
4154 * of contiguous memory as there's no hardware page translation to
4155 * assemble apparent contiguous memory from discontiguous pages.
4157 * Queueing large contiguous runs of pages for batching, however,
4158 * causes the pages to actually be freed in smaller chunks. As there
4159 * can be a significant delay between the individual batches being
4160 * recycled, this leads to the once large chunks of space being
4161 * fragmented and becoming unavailable for high-order allocations.
4168 * pcp->high and pcp->batch values are related and dependent on one another:
4169 * ->batch must never be higher then ->high.
4170 * The following function updates them in a safe manner without read side
4173 * Any new users of pcp->batch and pcp->high should ensure they can cope with
4174 * those fields changing asynchronously (acording the the above rule).
4176 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
4177 * outside of boot time (or some other assurance that no concurrent updaters
4180 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
4181 unsigned long batch
)
4183 /* start with a fail safe value for batch */
4187 /* Update high, then batch, in order */
4194 /* a companion to pageset_set_high() */
4195 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
4197 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
4200 static void pageset_init(struct per_cpu_pageset
*p
)
4202 struct per_cpu_pages
*pcp
;
4205 memset(p
, 0, sizeof(*p
));
4209 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
4210 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
4213 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
4216 pageset_set_batch(p
, batch
);
4220 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
4221 * to the value high for the pageset p.
4223 static void pageset_set_high(struct per_cpu_pageset
*p
,
4226 unsigned long batch
= max(1UL, high
/ 4);
4227 if ((high
/ 4) > (PAGE_SHIFT
* 8))
4228 batch
= PAGE_SHIFT
* 8;
4230 pageset_update(&p
->pcp
, high
, batch
);
4233 static void __meminit
pageset_set_high_and_batch(struct zone
*zone
,
4234 struct per_cpu_pageset
*pcp
)
4236 if (percpu_pagelist_fraction
)
4237 pageset_set_high(pcp
,
4238 (zone
->managed_pages
/
4239 percpu_pagelist_fraction
));
4241 pageset_set_batch(pcp
, zone_batchsize(zone
));
4244 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
4246 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
4249 pageset_set_high_and_batch(zone
, pcp
);
4252 static void __meminit
setup_zone_pageset(struct zone
*zone
)
4255 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
4256 for_each_possible_cpu(cpu
)
4257 zone_pageset_init(zone
, cpu
);
4261 * Allocate per cpu pagesets and initialize them.
4262 * Before this call only boot pagesets were available.
4264 void __init
setup_per_cpu_pageset(void)
4268 for_each_populated_zone(zone
)
4269 setup_zone_pageset(zone
);
4272 static noinline __init_refok
4273 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
4279 * The per-page waitqueue mechanism uses hashed waitqueues
4282 zone
->wait_table_hash_nr_entries
=
4283 wait_table_hash_nr_entries(zone_size_pages
);
4284 zone
->wait_table_bits
=
4285 wait_table_bits(zone
->wait_table_hash_nr_entries
);
4286 alloc_size
= zone
->wait_table_hash_nr_entries
4287 * sizeof(wait_queue_head_t
);
4289 if (!slab_is_available()) {
4290 zone
->wait_table
= (wait_queue_head_t
*)
4291 memblock_virt_alloc_node_nopanic(
4292 alloc_size
, zone
->zone_pgdat
->node_id
);
4295 * This case means that a zone whose size was 0 gets new memory
4296 * via memory hot-add.
4297 * But it may be the case that a new node was hot-added. In
4298 * this case vmalloc() will not be able to use this new node's
4299 * memory - this wait_table must be initialized to use this new
4300 * node itself as well.
4301 * To use this new node's memory, further consideration will be
4304 zone
->wait_table
= vmalloc(alloc_size
);
4306 if (!zone
->wait_table
)
4309 for (i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
4310 init_waitqueue_head(zone
->wait_table
+ i
);
4315 static __meminit
void zone_pcp_init(struct zone
*zone
)
4318 * per cpu subsystem is not up at this point. The following code
4319 * relies on the ability of the linker to provide the
4320 * offset of a (static) per cpu variable into the per cpu area.
4322 zone
->pageset
= &boot_pageset
;
4324 if (populated_zone(zone
))
4325 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
4326 zone
->name
, zone
->present_pages
,
4327 zone_batchsize(zone
));
4330 int __meminit
init_currently_empty_zone(struct zone
*zone
,
4331 unsigned long zone_start_pfn
,
4333 enum memmap_context context
)
4335 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
4337 ret
= zone_wait_table_init(zone
, size
);
4340 pgdat
->nr_zones
= zone_idx(zone
) + 1;
4342 zone
->zone_start_pfn
= zone_start_pfn
;
4344 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
4345 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4347 (unsigned long)zone_idx(zone
),
4348 zone_start_pfn
, (zone_start_pfn
+ size
));
4350 zone_init_free_lists(zone
);
4355 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4356 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4358 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4359 * Architectures may implement their own version but if add_active_range()
4360 * was used and there are no special requirements, this is a convenient
4363 int __meminit
__early_pfn_to_nid(unsigned long pfn
)
4365 unsigned long start_pfn
, end_pfn
;
4368 * NOTE: The following SMP-unsafe globals are only used early in boot
4369 * when the kernel is running single-threaded.
4371 static unsigned long __meminitdata last_start_pfn
, last_end_pfn
;
4372 static int __meminitdata last_nid
;
4374 if (last_start_pfn
<= pfn
&& pfn
< last_end_pfn
)
4377 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
4379 last_start_pfn
= start_pfn
;
4380 last_end_pfn
= end_pfn
;
4386 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
4388 int __meminit
early_pfn_to_nid(unsigned long pfn
)
4392 nid
= __early_pfn_to_nid(pfn
);
4395 /* just returns 0 */
4399 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
4400 bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
4404 nid
= __early_pfn_to_nid(pfn
);
4405 if (nid
>= 0 && nid
!= node
)
4412 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
4413 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
4414 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
4416 * If an architecture guarantees that all ranges registered with
4417 * add_active_ranges() contain no holes and may be freed, this
4418 * this function may be used instead of calling memblock_free_early_nid()
4421 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
4423 unsigned long start_pfn
, end_pfn
;
4426 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
4427 start_pfn
= min(start_pfn
, max_low_pfn
);
4428 end_pfn
= min(end_pfn
, max_low_pfn
);
4430 if (start_pfn
< end_pfn
)
4431 memblock_free_early_nid(PFN_PHYS(start_pfn
),
4432 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
4438 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4439 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4441 * If an architecture guarantees that all ranges registered with
4442 * add_active_ranges() contain no holes and may be freed, this
4443 * function may be used instead of calling memory_present() manually.
4445 void __init
sparse_memory_present_with_active_regions(int nid
)
4447 unsigned long start_pfn
, end_pfn
;
4450 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
4451 memory_present(this_nid
, start_pfn
, end_pfn
);
4455 * get_pfn_range_for_nid - Return the start and end page frames for a node
4456 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4457 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
4458 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
4460 * It returns the start and end page frame of a node based on information
4461 * provided by an arch calling add_active_range(). If called for a node
4462 * with no available memory, a warning is printed and the start and end
4465 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
4466 unsigned long *start_pfn
, unsigned long *end_pfn
)
4468 unsigned long this_start_pfn
, this_end_pfn
;
4474 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
4475 *start_pfn
= min(*start_pfn
, this_start_pfn
);
4476 *end_pfn
= max(*end_pfn
, this_end_pfn
);
4479 if (*start_pfn
== -1UL)
4484 * This finds a zone that can be used for ZONE_MOVABLE pages. The
4485 * assumption is made that zones within a node are ordered in monotonic
4486 * increasing memory addresses so that the "highest" populated zone is used
4488 static void __init
find_usable_zone_for_movable(void)
4491 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
4492 if (zone_index
== ZONE_MOVABLE
)
4495 if (arch_zone_highest_possible_pfn
[zone_index
] >
4496 arch_zone_lowest_possible_pfn
[zone_index
])
4500 VM_BUG_ON(zone_index
== -1);
4501 movable_zone
= zone_index
;
4505 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4506 * because it is sized independent of architecture. Unlike the other zones,
4507 * the starting point for ZONE_MOVABLE is not fixed. It may be different
4508 * in each node depending on the size of each node and how evenly kernelcore
4509 * is distributed. This helper function adjusts the zone ranges
4510 * provided by the architecture for a given node by using the end of the
4511 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4512 * zones within a node are in order of monotonic increases memory addresses
4514 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
4515 unsigned long zone_type
,
4516 unsigned long node_start_pfn
,
4517 unsigned long node_end_pfn
,
4518 unsigned long *zone_start_pfn
,
4519 unsigned long *zone_end_pfn
)
4521 /* Only adjust if ZONE_MOVABLE is on this node */
4522 if (zone_movable_pfn
[nid
]) {
4523 /* Size ZONE_MOVABLE */
4524 if (zone_type
== ZONE_MOVABLE
) {
4525 *zone_start_pfn
= zone_movable_pfn
[nid
];
4526 *zone_end_pfn
= min(node_end_pfn
,
4527 arch_zone_highest_possible_pfn
[movable_zone
]);
4529 /* Adjust for ZONE_MOVABLE starting within this range */
4530 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
4531 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
4532 *zone_end_pfn
= zone_movable_pfn
[nid
];
4534 /* Check if this whole range is within ZONE_MOVABLE */
4535 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
4536 *zone_start_pfn
= *zone_end_pfn
;
4541 * Return the number of pages a zone spans in a node, including holes
4542 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4544 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4545 unsigned long zone_type
,
4546 unsigned long node_start_pfn
,
4547 unsigned long node_end_pfn
,
4548 unsigned long *ignored
)
4550 unsigned long zone_start_pfn
, zone_end_pfn
;
4552 /* Get the start and end of the zone */
4553 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
4554 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
4555 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4556 node_start_pfn
, node_end_pfn
,
4557 &zone_start_pfn
, &zone_end_pfn
);
4559 /* Check that this node has pages within the zone's required range */
4560 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
4563 /* Move the zone boundaries inside the node if necessary */
4564 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
4565 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
4567 /* Return the spanned pages */
4568 return zone_end_pfn
- zone_start_pfn
;
4572 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4573 * then all holes in the requested range will be accounted for.
4575 unsigned long __meminit
__absent_pages_in_range(int nid
,
4576 unsigned long range_start_pfn
,
4577 unsigned long range_end_pfn
)
4579 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
4580 unsigned long start_pfn
, end_pfn
;
4583 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
4584 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
4585 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
4586 nr_absent
-= end_pfn
- start_pfn
;
4592 * absent_pages_in_range - Return number of page frames in holes within a range
4593 * @start_pfn: The start PFN to start searching for holes
4594 * @end_pfn: The end PFN to stop searching for holes
4596 * It returns the number of pages frames in memory holes within a range.
4598 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
4599 unsigned long end_pfn
)
4601 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
4604 /* Return the number of page frames in holes in a zone on a node */
4605 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4606 unsigned long zone_type
,
4607 unsigned long node_start_pfn
,
4608 unsigned long node_end_pfn
,
4609 unsigned long *ignored
)
4611 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
4612 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
4613 unsigned long zone_start_pfn
, zone_end_pfn
;
4615 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
4616 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
4618 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4619 node_start_pfn
, node_end_pfn
,
4620 &zone_start_pfn
, &zone_end_pfn
);
4621 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
4624 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4625 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4626 unsigned long zone_type
,
4627 unsigned long node_start_pfn
,
4628 unsigned long node_end_pfn
,
4629 unsigned long *zones_size
)
4631 return zones_size
[zone_type
];
4634 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4635 unsigned long zone_type
,
4636 unsigned long node_start_pfn
,
4637 unsigned long node_end_pfn
,
4638 unsigned long *zholes_size
)
4643 return zholes_size
[zone_type
];
4646 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4648 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
4649 unsigned long node_start_pfn
,
4650 unsigned long node_end_pfn
,
4651 unsigned long *zones_size
,
4652 unsigned long *zholes_size
)
4654 unsigned long realtotalpages
, totalpages
= 0;
4657 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4658 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
4662 pgdat
->node_spanned_pages
= totalpages
;
4664 realtotalpages
= totalpages
;
4665 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4667 zone_absent_pages_in_node(pgdat
->node_id
, i
,
4668 node_start_pfn
, node_end_pfn
,
4670 pgdat
->node_present_pages
= realtotalpages
;
4671 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
4675 #ifndef CONFIG_SPARSEMEM
4677 * Calculate the size of the zone->blockflags rounded to an unsigned long
4678 * Start by making sure zonesize is a multiple of pageblock_order by rounding
4679 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4680 * round what is now in bits to nearest long in bits, then return it in
4683 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
4685 unsigned long usemapsize
;
4687 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
4688 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
4689 usemapsize
= usemapsize
>> pageblock_order
;
4690 usemapsize
*= NR_PAGEBLOCK_BITS
;
4691 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
4693 return usemapsize
/ 8;
4696 static void __init
setup_usemap(struct pglist_data
*pgdat
,
4698 unsigned long zone_start_pfn
,
4699 unsigned long zonesize
)
4701 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
4702 zone
->pageblock_flags
= NULL
;
4704 zone
->pageblock_flags
=
4705 memblock_virt_alloc_node_nopanic(usemapsize
,
4709 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
4710 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
4711 #endif /* CONFIG_SPARSEMEM */
4713 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4715 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4716 void __paginginit
set_pageblock_order(void)
4720 /* Check that pageblock_nr_pages has not already been setup */
4721 if (pageblock_order
)
4724 if (HPAGE_SHIFT
> PAGE_SHIFT
)
4725 order
= HUGETLB_PAGE_ORDER
;
4727 order
= MAX_ORDER
- 1;
4730 * Assume the largest contiguous order of interest is a huge page.
4731 * This value may be variable depending on boot parameters on IA64 and
4734 pageblock_order
= order
;
4736 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4739 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4740 * is unused as pageblock_order is set at compile-time. See
4741 * include/linux/pageblock-flags.h for the values of pageblock_order based on
4744 void __paginginit
set_pageblock_order(void)
4748 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4750 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
4751 unsigned long present_pages
)
4753 unsigned long pages
= spanned_pages
;
4756 * Provide a more accurate estimation if there are holes within
4757 * the zone and SPARSEMEM is in use. If there are holes within the
4758 * zone, each populated memory region may cost us one or two extra
4759 * memmap pages due to alignment because memmap pages for each
4760 * populated regions may not naturally algined on page boundary.
4761 * So the (present_pages >> 4) heuristic is a tradeoff for that.
4763 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
4764 IS_ENABLED(CONFIG_SPARSEMEM
))
4765 pages
= present_pages
;
4767 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
4771 * Set up the zone data structures:
4772 * - mark all pages reserved
4773 * - mark all memory queues empty
4774 * - clear the memory bitmaps
4776 * NOTE: pgdat should get zeroed by caller.
4778 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
,
4779 unsigned long node_start_pfn
, unsigned long node_end_pfn
,
4780 unsigned long *zones_size
, unsigned long *zholes_size
)
4783 int nid
= pgdat
->node_id
;
4784 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
4787 pgdat_resize_init(pgdat
);
4788 #ifdef CONFIG_NUMA_BALANCING
4789 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
4790 pgdat
->numabalancing_migrate_nr_pages
= 0;
4791 pgdat
->numabalancing_migrate_next_window
= jiffies
;
4793 init_waitqueue_head(&pgdat
->kswapd_wait
);
4794 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
4795 pgdat_page_cgroup_init(pgdat
);
4797 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4798 struct zone
*zone
= pgdat
->node_zones
+ j
;
4799 unsigned long size
, realsize
, freesize
, memmap_pages
;
4801 size
= zone_spanned_pages_in_node(nid
, j
, node_start_pfn
,
4802 node_end_pfn
, zones_size
);
4803 realsize
= freesize
= size
- zone_absent_pages_in_node(nid
, j
,
4809 * Adjust freesize so that it accounts for how much memory
4810 * is used by this zone for memmap. This affects the watermark
4811 * and per-cpu initialisations
4813 memmap_pages
= calc_memmap_size(size
, realsize
);
4814 if (freesize
>= memmap_pages
) {
4815 freesize
-= memmap_pages
;
4818 " %s zone: %lu pages used for memmap\n",
4819 zone_names
[j
], memmap_pages
);
4822 " %s zone: %lu pages exceeds freesize %lu\n",
4823 zone_names
[j
], memmap_pages
, freesize
);
4825 /* Account for reserved pages */
4826 if (j
== 0 && freesize
> dma_reserve
) {
4827 freesize
-= dma_reserve
;
4828 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
4829 zone_names
[0], dma_reserve
);
4832 if (!is_highmem_idx(j
))
4833 nr_kernel_pages
+= freesize
;
4834 /* Charge for highmem memmap if there are enough kernel pages */
4835 else if (nr_kernel_pages
> memmap_pages
* 2)
4836 nr_kernel_pages
-= memmap_pages
;
4837 nr_all_pages
+= freesize
;
4839 zone
->spanned_pages
= size
;
4840 zone
->present_pages
= realsize
;
4842 * Set an approximate value for lowmem here, it will be adjusted
4843 * when the bootmem allocator frees pages into the buddy system.
4844 * And all highmem pages will be managed by the buddy system.
4846 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
4849 zone
->min_unmapped_pages
= (freesize
*sysctl_min_unmapped_ratio
)
4851 zone
->min_slab_pages
= (freesize
* sysctl_min_slab_ratio
) / 100;
4853 zone
->name
= zone_names
[j
];
4854 spin_lock_init(&zone
->lock
);
4855 spin_lock_init(&zone
->lru_lock
);
4856 zone_seqlock_init(zone
);
4857 zone
->zone_pgdat
= pgdat
;
4858 zone_pcp_init(zone
);
4860 /* For bootup, initialized properly in watermark setup */
4861 mod_zone_page_state(zone
, NR_ALLOC_BATCH
, zone
->managed_pages
);
4863 lruvec_init(&zone
->lruvec
);
4867 set_pageblock_order();
4868 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
4869 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
4870 size
, MEMMAP_EARLY
);
4872 memmap_init(size
, nid
, j
, zone_start_pfn
);
4873 zone_start_pfn
+= size
;
4877 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
4879 /* Skip empty nodes */
4880 if (!pgdat
->node_spanned_pages
)
4883 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4884 /* ia64 gets its own node_mem_map, before this, without bootmem */
4885 if (!pgdat
->node_mem_map
) {
4886 unsigned long size
, start
, end
;
4890 * The zone's endpoints aren't required to be MAX_ORDER
4891 * aligned but the node_mem_map endpoints must be in order
4892 * for the buddy allocator to function correctly.
4894 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
4895 end
= pgdat_end_pfn(pgdat
);
4896 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
4897 size
= (end
- start
) * sizeof(struct page
);
4898 map
= alloc_remap(pgdat
->node_id
, size
);
4900 map
= memblock_virt_alloc_node_nopanic(size
,
4902 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
4904 #ifndef CONFIG_NEED_MULTIPLE_NODES
4906 * With no DISCONTIG, the global mem_map is just set as node 0's
4908 if (pgdat
== NODE_DATA(0)) {
4909 mem_map
= NODE_DATA(0)->node_mem_map
;
4910 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4911 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
4912 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
4913 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4916 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
4919 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
4920 unsigned long node_start_pfn
, unsigned long *zholes_size
)
4922 pg_data_t
*pgdat
= NODE_DATA(nid
);
4923 unsigned long start_pfn
= 0;
4924 unsigned long end_pfn
= 0;
4926 /* pg_data_t should be reset to zero when it's allocated */
4927 WARN_ON(pgdat
->nr_zones
|| pgdat
->classzone_idx
);
4929 pgdat
->node_id
= nid
;
4930 pgdat
->node_start_pfn
= node_start_pfn
;
4931 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4932 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
4934 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
4935 zones_size
, zholes_size
);
4937 alloc_node_mem_map(pgdat
);
4938 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4939 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
4940 nid
, (unsigned long)pgdat
,
4941 (unsigned long)pgdat
->node_mem_map
);
4944 free_area_init_core(pgdat
, start_pfn
, end_pfn
,
4945 zones_size
, zholes_size
);
4948 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4950 #if MAX_NUMNODES > 1
4952 * Figure out the number of possible node ids.
4954 void __init
setup_nr_node_ids(void)
4957 unsigned int highest
= 0;
4959 for_each_node_mask(node
, node_possible_map
)
4961 nr_node_ids
= highest
+ 1;
4966 * node_map_pfn_alignment - determine the maximum internode alignment
4968 * This function should be called after node map is populated and sorted.
4969 * It calculates the maximum power of two alignment which can distinguish
4972 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
4973 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
4974 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
4975 * shifted, 1GiB is enough and this function will indicate so.
4977 * This is used to test whether pfn -> nid mapping of the chosen memory
4978 * model has fine enough granularity to avoid incorrect mapping for the
4979 * populated node map.
4981 * Returns the determined alignment in pfn's. 0 if there is no alignment
4982 * requirement (single node).
4984 unsigned long __init
node_map_pfn_alignment(void)
4986 unsigned long accl_mask
= 0, last_end
= 0;
4987 unsigned long start
, end
, mask
;
4991 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
4992 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
4999 * Start with a mask granular enough to pin-point to the
5000 * start pfn and tick off bits one-by-one until it becomes
5001 * too coarse to separate the current node from the last.
5003 mask
= ~((1 << __ffs(start
)) - 1);
5004 while (mask
&& last_end
<= (start
& (mask
<< 1)))
5007 /* accumulate all internode masks */
5011 /* convert mask to number of pages */
5012 return ~accl_mask
+ 1;
5015 /* Find the lowest pfn for a node */
5016 static unsigned long __init
find_min_pfn_for_node(int nid
)
5018 unsigned long min_pfn
= ULONG_MAX
;
5019 unsigned long start_pfn
;
5022 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
5023 min_pfn
= min(min_pfn
, start_pfn
);
5025 if (min_pfn
== ULONG_MAX
) {
5027 "Could not find start_pfn for node %d\n", nid
);
5035 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5037 * It returns the minimum PFN based on information provided via
5038 * add_active_range().
5040 unsigned long __init
find_min_pfn_with_active_regions(void)
5042 return find_min_pfn_for_node(MAX_NUMNODES
);
5046 * early_calculate_totalpages()
5047 * Sum pages in active regions for movable zone.
5048 * Populate N_MEMORY for calculating usable_nodes.
5050 static unsigned long __init
early_calculate_totalpages(void)
5052 unsigned long totalpages
= 0;
5053 unsigned long start_pfn
, end_pfn
;
5056 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
5057 unsigned long pages
= end_pfn
- start_pfn
;
5059 totalpages
+= pages
;
5061 node_set_state(nid
, N_MEMORY
);
5067 * Find the PFN the Movable zone begins in each node. Kernel memory
5068 * is spread evenly between nodes as long as the nodes have enough
5069 * memory. When they don't, some nodes will have more kernelcore than
5072 static void __init
find_zone_movable_pfns_for_nodes(void)
5075 unsigned long usable_startpfn
;
5076 unsigned long kernelcore_node
, kernelcore_remaining
;
5077 /* save the state before borrow the nodemask */
5078 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
5079 unsigned long totalpages
= early_calculate_totalpages();
5080 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
5081 struct memblock_region
*r
;
5083 /* Need to find movable_zone earlier when movable_node is specified. */
5084 find_usable_zone_for_movable();
5087 * If movable_node is specified, ignore kernelcore and movablecore
5090 if (movable_node_is_enabled()) {
5091 for_each_memblock(memory
, r
) {
5092 if (!memblock_is_hotpluggable(r
))
5097 usable_startpfn
= PFN_DOWN(r
->base
);
5098 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
5099 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
5107 * If movablecore=nn[KMG] was specified, calculate what size of
5108 * kernelcore that corresponds so that memory usable for
5109 * any allocation type is evenly spread. If both kernelcore
5110 * and movablecore are specified, then the value of kernelcore
5111 * will be used for required_kernelcore if it's greater than
5112 * what movablecore would have allowed.
5114 if (required_movablecore
) {
5115 unsigned long corepages
;
5118 * Round-up so that ZONE_MOVABLE is at least as large as what
5119 * was requested by the user
5121 required_movablecore
=
5122 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
5123 corepages
= totalpages
- required_movablecore
;
5125 required_kernelcore
= max(required_kernelcore
, corepages
);
5128 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
5129 if (!required_kernelcore
)
5132 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
5133 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
5136 /* Spread kernelcore memory as evenly as possible throughout nodes */
5137 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5138 for_each_node_state(nid
, N_MEMORY
) {
5139 unsigned long start_pfn
, end_pfn
;
5142 * Recalculate kernelcore_node if the division per node
5143 * now exceeds what is necessary to satisfy the requested
5144 * amount of memory for the kernel
5146 if (required_kernelcore
< kernelcore_node
)
5147 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5150 * As the map is walked, we track how much memory is usable
5151 * by the kernel using kernelcore_remaining. When it is
5152 * 0, the rest of the node is usable by ZONE_MOVABLE
5154 kernelcore_remaining
= kernelcore_node
;
5156 /* Go through each range of PFNs within this node */
5157 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5158 unsigned long size_pages
;
5160 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
5161 if (start_pfn
>= end_pfn
)
5164 /* Account for what is only usable for kernelcore */
5165 if (start_pfn
< usable_startpfn
) {
5166 unsigned long kernel_pages
;
5167 kernel_pages
= min(end_pfn
, usable_startpfn
)
5170 kernelcore_remaining
-= min(kernel_pages
,
5171 kernelcore_remaining
);
5172 required_kernelcore
-= min(kernel_pages
,
5173 required_kernelcore
);
5175 /* Continue if range is now fully accounted */
5176 if (end_pfn
<= usable_startpfn
) {
5179 * Push zone_movable_pfn to the end so
5180 * that if we have to rebalance
5181 * kernelcore across nodes, we will
5182 * not double account here
5184 zone_movable_pfn
[nid
] = end_pfn
;
5187 start_pfn
= usable_startpfn
;
5191 * The usable PFN range for ZONE_MOVABLE is from
5192 * start_pfn->end_pfn. Calculate size_pages as the
5193 * number of pages used as kernelcore
5195 size_pages
= end_pfn
- start_pfn
;
5196 if (size_pages
> kernelcore_remaining
)
5197 size_pages
= kernelcore_remaining
;
5198 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
5201 * Some kernelcore has been met, update counts and
5202 * break if the kernelcore for this node has been
5205 required_kernelcore
-= min(required_kernelcore
,
5207 kernelcore_remaining
-= size_pages
;
5208 if (!kernelcore_remaining
)
5214 * If there is still required_kernelcore, we do another pass with one
5215 * less node in the count. This will push zone_movable_pfn[nid] further
5216 * along on the nodes that still have memory until kernelcore is
5220 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
5224 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5225 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
5226 zone_movable_pfn
[nid
] =
5227 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
5230 /* restore the node_state */
5231 node_states
[N_MEMORY
] = saved_node_state
;
5234 /* Any regular or high memory on that node ? */
5235 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
5237 enum zone_type zone_type
;
5239 if (N_MEMORY
== N_NORMAL_MEMORY
)
5242 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
5243 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
5244 if (populated_zone(zone
)) {
5245 node_set_state(nid
, N_HIGH_MEMORY
);
5246 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
5247 zone_type
<= ZONE_NORMAL
)
5248 node_set_state(nid
, N_NORMAL_MEMORY
);
5255 * free_area_init_nodes - Initialise all pg_data_t and zone data
5256 * @max_zone_pfn: an array of max PFNs for each zone
5258 * This will call free_area_init_node() for each active node in the system.
5259 * Using the page ranges provided by add_active_range(), the size of each
5260 * zone in each node and their holes is calculated. If the maximum PFN
5261 * between two adjacent zones match, it is assumed that the zone is empty.
5262 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
5263 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
5264 * starts where the previous one ended. For example, ZONE_DMA32 starts
5265 * at arch_max_dma_pfn.
5267 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
5269 unsigned long start_pfn
, end_pfn
;
5272 /* Record where the zone boundaries are */
5273 memset(arch_zone_lowest_possible_pfn
, 0,
5274 sizeof(arch_zone_lowest_possible_pfn
));
5275 memset(arch_zone_highest_possible_pfn
, 0,
5276 sizeof(arch_zone_highest_possible_pfn
));
5277 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
5278 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
5279 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
5280 if (i
== ZONE_MOVABLE
)
5282 arch_zone_lowest_possible_pfn
[i
] =
5283 arch_zone_highest_possible_pfn
[i
-1];
5284 arch_zone_highest_possible_pfn
[i
] =
5285 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
5287 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
5288 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
5290 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
5291 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
5292 find_zone_movable_pfns_for_nodes();
5294 /* Print out the zone ranges */
5295 printk("Zone ranges:\n");
5296 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5297 if (i
== ZONE_MOVABLE
)
5299 printk(KERN_CONT
" %-8s ", zone_names
[i
]);
5300 if (arch_zone_lowest_possible_pfn
[i
] ==
5301 arch_zone_highest_possible_pfn
[i
])
5302 printk(KERN_CONT
"empty\n");
5304 printk(KERN_CONT
"[mem %0#10lx-%0#10lx]\n",
5305 arch_zone_lowest_possible_pfn
[i
] << PAGE_SHIFT
,
5306 (arch_zone_highest_possible_pfn
[i
]
5307 << PAGE_SHIFT
) - 1);
5310 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
5311 printk("Movable zone start for each node\n");
5312 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
5313 if (zone_movable_pfn
[i
])
5314 printk(" Node %d: %#010lx\n", i
,
5315 zone_movable_pfn
[i
] << PAGE_SHIFT
);
5318 /* Print out the early node map */
5319 printk("Early memory node ranges\n");
5320 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
5321 printk(" node %3d: [mem %#010lx-%#010lx]\n", nid
,
5322 start_pfn
<< PAGE_SHIFT
, (end_pfn
<< PAGE_SHIFT
) - 1);
5324 /* Initialise every node */
5325 mminit_verify_pageflags_layout();
5326 setup_nr_node_ids();
5327 for_each_online_node(nid
) {
5328 pg_data_t
*pgdat
= NODE_DATA(nid
);
5329 free_area_init_node(nid
, NULL
,
5330 find_min_pfn_for_node(nid
), NULL
);
5332 /* Any memory on that node */
5333 if (pgdat
->node_present_pages
)
5334 node_set_state(nid
, N_MEMORY
);
5335 check_for_memory(pgdat
, nid
);
5339 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
5341 unsigned long long coremem
;
5345 coremem
= memparse(p
, &p
);
5346 *core
= coremem
>> PAGE_SHIFT
;
5348 /* Paranoid check that UL is enough for the coremem value */
5349 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
5355 * kernelcore=size sets the amount of memory for use for allocations that
5356 * cannot be reclaimed or migrated.
5358 static int __init
cmdline_parse_kernelcore(char *p
)
5360 return cmdline_parse_core(p
, &required_kernelcore
);
5364 * movablecore=size sets the amount of memory for use for allocations that
5365 * can be reclaimed or migrated.
5367 static int __init
cmdline_parse_movablecore(char *p
)
5369 return cmdline_parse_core(p
, &required_movablecore
);
5372 early_param("kernelcore", cmdline_parse_kernelcore
);
5373 early_param("movablecore", cmdline_parse_movablecore
);
5375 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5377 void adjust_managed_page_count(struct page
*page
, long count
)
5379 spin_lock(&managed_page_count_lock
);
5380 page_zone(page
)->managed_pages
+= count
;
5381 totalram_pages
+= count
;
5382 #ifdef CONFIG_HIGHMEM
5383 if (PageHighMem(page
))
5384 totalhigh_pages
+= count
;
5386 spin_unlock(&managed_page_count_lock
);
5388 EXPORT_SYMBOL(adjust_managed_page_count
);
5390 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
5393 unsigned long pages
= 0;
5395 start
= (void *)PAGE_ALIGN((unsigned long)start
);
5396 end
= (void *)((unsigned long)end
& PAGE_MASK
);
5397 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
5398 if ((unsigned int)poison
<= 0xFF)
5399 memset(pos
, poison
, PAGE_SIZE
);
5400 free_reserved_page(virt_to_page(pos
));
5404 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
5405 s
, pages
<< (PAGE_SHIFT
- 10), start
, end
);
5409 EXPORT_SYMBOL(free_reserved_area
);
5411 #ifdef CONFIG_HIGHMEM
5412 void free_highmem_page(struct page
*page
)
5414 __free_reserved_page(page
);
5416 page_zone(page
)->managed_pages
++;
5422 void __init
mem_init_print_info(const char *str
)
5424 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
5425 unsigned long init_code_size
, init_data_size
;
5427 physpages
= get_num_physpages();
5428 codesize
= _etext
- _stext
;
5429 datasize
= _edata
- _sdata
;
5430 rosize
= __end_rodata
- __start_rodata
;
5431 bss_size
= __bss_stop
- __bss_start
;
5432 init_data_size
= __init_end
- __init_begin
;
5433 init_code_size
= _einittext
- _sinittext
;
5436 * Detect special cases and adjust section sizes accordingly:
5437 * 1) .init.* may be embedded into .data sections
5438 * 2) .init.text.* may be out of [__init_begin, __init_end],
5439 * please refer to arch/tile/kernel/vmlinux.lds.S.
5440 * 3) .rodata.* may be embedded into .text or .data sections.
5442 #define adj_init_size(start, end, size, pos, adj) \
5444 if (start <= pos && pos < end && size > adj) \
5448 adj_init_size(__init_begin
, __init_end
, init_data_size
,
5449 _sinittext
, init_code_size
);
5450 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
5451 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
5452 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
5453 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
5455 #undef adj_init_size
5457 printk("Memory: %luK/%luK available "
5458 "(%luK kernel code, %luK rwdata, %luK rodata, "
5459 "%luK init, %luK bss, %luK reserved"
5460 #ifdef CONFIG_HIGHMEM
5464 nr_free_pages() << (PAGE_SHIFT
-10), physpages
<< (PAGE_SHIFT
-10),
5465 codesize
>> 10, datasize
>> 10, rosize
>> 10,
5466 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
5467 (physpages
- totalram_pages
) << (PAGE_SHIFT
-10),
5468 #ifdef CONFIG_HIGHMEM
5469 totalhigh_pages
<< (PAGE_SHIFT
-10),
5471 str
? ", " : "", str
? str
: "");
5475 * set_dma_reserve - set the specified number of pages reserved in the first zone
5476 * @new_dma_reserve: The number of pages to mark reserved
5478 * The per-cpu batchsize and zone watermarks are determined by present_pages.
5479 * In the DMA zone, a significant percentage may be consumed by kernel image
5480 * and other unfreeable allocations which can skew the watermarks badly. This
5481 * function may optionally be used to account for unfreeable pages in the
5482 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
5483 * smaller per-cpu batchsize.
5485 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
5487 dma_reserve
= new_dma_reserve
;
5490 void __init
free_area_init(unsigned long *zones_size
)
5492 free_area_init_node(0, zones_size
,
5493 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
5496 static int page_alloc_cpu_notify(struct notifier_block
*self
,
5497 unsigned long action
, void *hcpu
)
5499 int cpu
= (unsigned long)hcpu
;
5501 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
5502 lru_add_drain_cpu(cpu
);
5506 * Spill the event counters of the dead processor
5507 * into the current processors event counters.
5508 * This artificially elevates the count of the current
5511 vm_events_fold_cpu(cpu
);
5514 * Zero the differential counters of the dead processor
5515 * so that the vm statistics are consistent.
5517 * This is only okay since the processor is dead and cannot
5518 * race with what we are doing.
5520 cpu_vm_stats_fold(cpu
);
5525 void __init
page_alloc_init(void)
5527 hotcpu_notifier(page_alloc_cpu_notify
, 0);
5531 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
5532 * or min_free_kbytes changes.
5534 static void calculate_totalreserve_pages(void)
5536 struct pglist_data
*pgdat
;
5537 unsigned long reserve_pages
= 0;
5538 enum zone_type i
, j
;
5540 for_each_online_pgdat(pgdat
) {
5541 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5542 struct zone
*zone
= pgdat
->node_zones
+ i
;
5543 unsigned long max
= 0;
5545 /* Find valid and maximum lowmem_reserve in the zone */
5546 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
5547 if (zone
->lowmem_reserve
[j
] > max
)
5548 max
= zone
->lowmem_reserve
[j
];
5551 /* we treat the high watermark as reserved pages. */
5552 max
+= high_wmark_pages(zone
);
5554 if (max
> zone
->managed_pages
)
5555 max
= zone
->managed_pages
;
5556 reserve_pages
+= max
;
5558 * Lowmem reserves are not available to
5559 * GFP_HIGHUSER page cache allocations and
5560 * kswapd tries to balance zones to their high
5561 * watermark. As a result, neither should be
5562 * regarded as dirtyable memory, to prevent a
5563 * situation where reclaim has to clean pages
5564 * in order to balance the zones.
5566 zone
->dirty_balance_reserve
= max
;
5569 dirty_balance_reserve
= reserve_pages
;
5570 totalreserve_pages
= reserve_pages
;
5574 * setup_per_zone_lowmem_reserve - called whenever
5575 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
5576 * has a correct pages reserved value, so an adequate number of
5577 * pages are left in the zone after a successful __alloc_pages().
5579 static void setup_per_zone_lowmem_reserve(void)
5581 struct pglist_data
*pgdat
;
5582 enum zone_type j
, idx
;
5584 for_each_online_pgdat(pgdat
) {
5585 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5586 struct zone
*zone
= pgdat
->node_zones
+ j
;
5587 unsigned long managed_pages
= zone
->managed_pages
;
5589 zone
->lowmem_reserve
[j
] = 0;
5593 struct zone
*lower_zone
;
5597 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
5598 sysctl_lowmem_reserve_ratio
[idx
] = 1;
5600 lower_zone
= pgdat
->node_zones
+ idx
;
5601 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
5602 sysctl_lowmem_reserve_ratio
[idx
];
5603 managed_pages
+= lower_zone
->managed_pages
;
5608 /* update totalreserve_pages */
5609 calculate_totalreserve_pages();
5612 static void __setup_per_zone_wmarks(void)
5614 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
5615 unsigned long lowmem_pages
= 0;
5617 unsigned long flags
;
5619 /* Calculate total number of !ZONE_HIGHMEM pages */
5620 for_each_zone(zone
) {
5621 if (!is_highmem(zone
))
5622 lowmem_pages
+= zone
->managed_pages
;
5625 for_each_zone(zone
) {
5628 spin_lock_irqsave(&zone
->lock
, flags
);
5629 tmp
= (u64
)pages_min
* zone
->managed_pages
;
5630 do_div(tmp
, lowmem_pages
);
5631 if (is_highmem(zone
)) {
5633 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
5634 * need highmem pages, so cap pages_min to a small
5637 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
5638 * deltas controls asynch page reclaim, and so should
5639 * not be capped for highmem.
5641 unsigned long min_pages
;
5643 min_pages
= zone
->managed_pages
/ 1024;
5644 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
5645 zone
->watermark
[WMARK_MIN
] = min_pages
;
5648 * If it's a lowmem zone, reserve a number of pages
5649 * proportionate to the zone's size.
5651 zone
->watermark
[WMARK_MIN
] = tmp
;
5654 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + (tmp
>> 2);
5655 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + (tmp
>> 1);
5657 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
5658 high_wmark_pages(zone
) -
5659 low_wmark_pages(zone
) -
5660 zone_page_state(zone
, NR_ALLOC_BATCH
));
5662 setup_zone_migrate_reserve(zone
);
5663 spin_unlock_irqrestore(&zone
->lock
, flags
);
5666 /* update totalreserve_pages */
5667 calculate_totalreserve_pages();
5671 * setup_per_zone_wmarks - called when min_free_kbytes changes
5672 * or when memory is hot-{added|removed}
5674 * Ensures that the watermark[min,low,high] values for each zone are set
5675 * correctly with respect to min_free_kbytes.
5677 void setup_per_zone_wmarks(void)
5679 mutex_lock(&zonelists_mutex
);
5680 __setup_per_zone_wmarks();
5681 mutex_unlock(&zonelists_mutex
);
5685 * The inactive anon list should be small enough that the VM never has to
5686 * do too much work, but large enough that each inactive page has a chance
5687 * to be referenced again before it is swapped out.
5689 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
5690 * INACTIVE_ANON pages on this zone's LRU, maintained by the
5691 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
5692 * the anonymous pages are kept on the inactive list.
5695 * memory ratio inactive anon
5696 * -------------------------------------
5705 static void __meminit
calculate_zone_inactive_ratio(struct zone
*zone
)
5707 unsigned int gb
, ratio
;
5709 /* Zone size in gigabytes */
5710 gb
= zone
->managed_pages
>> (30 - PAGE_SHIFT
);
5712 ratio
= int_sqrt(10 * gb
);
5716 zone
->inactive_ratio
= ratio
;
5719 static void __meminit
setup_per_zone_inactive_ratio(void)
5724 calculate_zone_inactive_ratio(zone
);
5728 * Initialise min_free_kbytes.
5730 * For small machines we want it small (128k min). For large machines
5731 * we want it large (64MB max). But it is not linear, because network
5732 * bandwidth does not increase linearly with machine size. We use
5734 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
5735 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
5751 int __meminit
init_per_zone_wmark_min(void)
5753 unsigned long lowmem_kbytes
;
5754 int new_min_free_kbytes
;
5756 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
5757 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
5759 if (new_min_free_kbytes
> user_min_free_kbytes
) {
5760 min_free_kbytes
= new_min_free_kbytes
;
5761 if (min_free_kbytes
< 128)
5762 min_free_kbytes
= 128;
5763 if (min_free_kbytes
> 65536)
5764 min_free_kbytes
= 65536;
5766 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
5767 new_min_free_kbytes
, user_min_free_kbytes
);
5769 setup_per_zone_wmarks();
5770 refresh_zone_stat_thresholds();
5771 setup_per_zone_lowmem_reserve();
5772 setup_per_zone_inactive_ratio();
5775 module_init(init_per_zone_wmark_min
)
5778 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5779 * that we can call two helper functions whenever min_free_kbytes
5782 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
5783 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5787 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5792 user_min_free_kbytes
= min_free_kbytes
;
5793 setup_per_zone_wmarks();
5799 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table
*table
, int write
,
5800 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5805 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5810 zone
->min_unmapped_pages
= (zone
->managed_pages
*
5811 sysctl_min_unmapped_ratio
) / 100;
5815 int sysctl_min_slab_ratio_sysctl_handler(ctl_table
*table
, int write
,
5816 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5821 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5826 zone
->min_slab_pages
= (zone
->managed_pages
*
5827 sysctl_min_slab_ratio
) / 100;
5833 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5834 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5835 * whenever sysctl_lowmem_reserve_ratio changes.
5837 * The reserve ratio obviously has absolutely no relation with the
5838 * minimum watermarks. The lowmem reserve ratio can only make sense
5839 * if in function of the boot time zone sizes.
5841 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
5842 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5844 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5845 setup_per_zone_lowmem_reserve();
5850 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5851 * cpu. It is the fraction of total pages in each zone that a hot per cpu
5852 * pagelist can have before it gets flushed back to buddy allocator.
5854 int percpu_pagelist_fraction_sysctl_handler(ctl_table
*table
, int write
,
5855 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5861 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5862 if (!write
|| (ret
< 0))
5865 mutex_lock(&pcp_batch_high_lock
);
5866 for_each_populated_zone(zone
) {
5868 high
= zone
->managed_pages
/ percpu_pagelist_fraction
;
5869 for_each_possible_cpu(cpu
)
5870 pageset_set_high(per_cpu_ptr(zone
->pageset
, cpu
),
5873 mutex_unlock(&pcp_batch_high_lock
);
5877 int hashdist
= HASHDIST_DEFAULT
;
5880 static int __init
set_hashdist(char *str
)
5884 hashdist
= simple_strtoul(str
, &str
, 0);
5887 __setup("hashdist=", set_hashdist
);
5891 * allocate a large system hash table from bootmem
5892 * - it is assumed that the hash table must contain an exact power-of-2
5893 * quantity of entries
5894 * - limit is the number of hash buckets, not the total allocation size
5896 void *__init
alloc_large_system_hash(const char *tablename
,
5897 unsigned long bucketsize
,
5898 unsigned long numentries
,
5901 unsigned int *_hash_shift
,
5902 unsigned int *_hash_mask
,
5903 unsigned long low_limit
,
5904 unsigned long high_limit
)
5906 unsigned long long max
= high_limit
;
5907 unsigned long log2qty
, size
;
5910 /* allow the kernel cmdline to have a say */
5912 /* round applicable memory size up to nearest megabyte */
5913 numentries
= nr_kernel_pages
;
5915 /* It isn't necessary when PAGE_SIZE >= 1MB */
5916 if (PAGE_SHIFT
< 20)
5917 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
5919 /* limit to 1 bucket per 2^scale bytes of low memory */
5920 if (scale
> PAGE_SHIFT
)
5921 numentries
>>= (scale
- PAGE_SHIFT
);
5923 numentries
<<= (PAGE_SHIFT
- scale
);
5925 /* Make sure we've got at least a 0-order allocation.. */
5926 if (unlikely(flags
& HASH_SMALL
)) {
5927 /* Makes no sense without HASH_EARLY */
5928 WARN_ON(!(flags
& HASH_EARLY
));
5929 if (!(numentries
>> *_hash_shift
)) {
5930 numentries
= 1UL << *_hash_shift
;
5931 BUG_ON(!numentries
);
5933 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
5934 numentries
= PAGE_SIZE
/ bucketsize
;
5936 numentries
= roundup_pow_of_two(numentries
);
5938 /* limit allocation size to 1/16 total memory by default */
5940 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
5941 do_div(max
, bucketsize
);
5943 max
= min(max
, 0x80000000ULL
);
5945 if (numentries
< low_limit
)
5946 numentries
= low_limit
;
5947 if (numentries
> max
)
5950 log2qty
= ilog2(numentries
);
5953 size
= bucketsize
<< log2qty
;
5954 if (flags
& HASH_EARLY
)
5955 table
= memblock_virt_alloc_nopanic(size
, 0);
5957 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
5960 * If bucketsize is not a power-of-two, we may free
5961 * some pages at the end of hash table which
5962 * alloc_pages_exact() automatically does
5964 if (get_order(size
) < MAX_ORDER
) {
5965 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
5966 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
5969 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
5972 panic("Failed to allocate %s hash table\n", tablename
);
5974 printk(KERN_INFO
"%s hash table entries: %ld (order: %d, %lu bytes)\n",
5977 ilog2(size
) - PAGE_SHIFT
,
5981 *_hash_shift
= log2qty
;
5983 *_hash_mask
= (1 << log2qty
) - 1;
5988 /* Return a pointer to the bitmap storing bits affecting a block of pages */
5989 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
5992 #ifdef CONFIG_SPARSEMEM
5993 return __pfn_to_section(pfn
)->pageblock_flags
;
5995 return zone
->pageblock_flags
;
5996 #endif /* CONFIG_SPARSEMEM */
5999 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
6001 #ifdef CONFIG_SPARSEMEM
6002 pfn
&= (PAGES_PER_SECTION
-1);
6003 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6005 pfn
= pfn
- round_down(zone
->zone_start_pfn
, pageblock_nr_pages
);
6006 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6007 #endif /* CONFIG_SPARSEMEM */
6011 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
6012 * @page: The page within the block of interest
6013 * @start_bitidx: The first bit of interest to retrieve
6014 * @end_bitidx: The last bit of interest
6015 * returns pageblock_bits flags
6017 unsigned long get_pageblock_flags_group(struct page
*page
,
6018 int start_bitidx
, int end_bitidx
)
6021 unsigned long *bitmap
;
6022 unsigned long pfn
, bitidx
;
6023 unsigned long flags
= 0;
6024 unsigned long value
= 1;
6026 zone
= page_zone(page
);
6027 pfn
= page_to_pfn(page
);
6028 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6029 bitidx
= pfn_to_bitidx(zone
, pfn
);
6031 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
6032 if (test_bit(bitidx
+ start_bitidx
, bitmap
))
6039 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
6040 * @page: The page within the block of interest
6041 * @start_bitidx: The first bit of interest
6042 * @end_bitidx: The last bit of interest
6043 * @flags: The flags to set
6045 void set_pageblock_flags_group(struct page
*page
, unsigned long flags
,
6046 int start_bitidx
, int end_bitidx
)
6049 unsigned long *bitmap
;
6050 unsigned long pfn
, bitidx
;
6051 unsigned long value
= 1;
6053 zone
= page_zone(page
);
6054 pfn
= page_to_pfn(page
);
6055 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6056 bitidx
= pfn_to_bitidx(zone
, pfn
);
6057 VM_BUG_ON_PAGE(!zone_spans_pfn(zone
, pfn
), page
);
6059 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
6061 __set_bit(bitidx
+ start_bitidx
, bitmap
);
6063 __clear_bit(bitidx
+ start_bitidx
, bitmap
);
6067 * This function checks whether pageblock includes unmovable pages or not.
6068 * If @count is not zero, it is okay to include less @count unmovable pages
6070 * PageLRU check without isolation or lru_lock could race so that
6071 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6072 * expect this function should be exact.
6074 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
6075 bool skip_hwpoisoned_pages
)
6077 unsigned long pfn
, iter
, found
;
6081 * For avoiding noise data, lru_add_drain_all() should be called
6082 * If ZONE_MOVABLE, the zone never contains unmovable pages
6084 if (zone_idx(zone
) == ZONE_MOVABLE
)
6086 mt
= get_pageblock_migratetype(page
);
6087 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
6090 pfn
= page_to_pfn(page
);
6091 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
6092 unsigned long check
= pfn
+ iter
;
6094 if (!pfn_valid_within(check
))
6097 page
= pfn_to_page(check
);
6100 * Hugepages are not in LRU lists, but they're movable.
6101 * We need not scan over tail pages bacause we don't
6102 * handle each tail page individually in migration.
6104 if (PageHuge(page
)) {
6105 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
6110 * We can't use page_count without pin a page
6111 * because another CPU can free compound page.
6112 * This check already skips compound tails of THP
6113 * because their page->_count is zero at all time.
6115 if (!atomic_read(&page
->_count
)) {
6116 if (PageBuddy(page
))
6117 iter
+= (1 << page_order(page
)) - 1;
6122 * The HWPoisoned page may be not in buddy system, and
6123 * page_count() is not 0.
6125 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
6131 * If there are RECLAIMABLE pages, we need to check it.
6132 * But now, memory offline itself doesn't call shrink_slab()
6133 * and it still to be fixed.
6136 * If the page is not RAM, page_count()should be 0.
6137 * we don't need more check. This is an _used_ not-movable page.
6139 * The problematic thing here is PG_reserved pages. PG_reserved
6140 * is set to both of a memory hole page and a _used_ kernel
6149 bool is_pageblock_removable_nolock(struct page
*page
)
6155 * We have to be careful here because we are iterating over memory
6156 * sections which are not zone aware so we might end up outside of
6157 * the zone but still within the section.
6158 * We have to take care about the node as well. If the node is offline
6159 * its NODE_DATA will be NULL - see page_zone.
6161 if (!node_online(page_to_nid(page
)))
6164 zone
= page_zone(page
);
6165 pfn
= page_to_pfn(page
);
6166 if (!zone_spans_pfn(zone
, pfn
))
6169 return !has_unmovable_pages(zone
, page
, 0, true);
6174 static unsigned long pfn_max_align_down(unsigned long pfn
)
6176 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6177 pageblock_nr_pages
) - 1);
6180 static unsigned long pfn_max_align_up(unsigned long pfn
)
6182 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6183 pageblock_nr_pages
));
6186 /* [start, end) must belong to a single zone. */
6187 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
6188 unsigned long start
, unsigned long end
)
6190 /* This function is based on compact_zone() from compaction.c. */
6191 unsigned long nr_reclaimed
;
6192 unsigned long pfn
= start
;
6193 unsigned int tries
= 0;
6198 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
6199 if (fatal_signal_pending(current
)) {
6204 if (list_empty(&cc
->migratepages
)) {
6205 cc
->nr_migratepages
= 0;
6206 pfn
= isolate_migratepages_range(cc
->zone
, cc
,
6213 } else if (++tries
== 5) {
6214 ret
= ret
< 0 ? ret
: -EBUSY
;
6218 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
6220 cc
->nr_migratepages
-= nr_reclaimed
;
6222 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
6223 NULL
, 0, cc
->mode
, MR_CMA
);
6226 putback_movable_pages(&cc
->migratepages
);
6233 * alloc_contig_range() -- tries to allocate given range of pages
6234 * @start: start PFN to allocate
6235 * @end: one-past-the-last PFN to allocate
6236 * @migratetype: migratetype of the underlaying pageblocks (either
6237 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
6238 * in range must have the same migratetype and it must
6239 * be either of the two.
6241 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
6242 * aligned, however it's the caller's responsibility to guarantee that
6243 * we are the only thread that changes migrate type of pageblocks the
6246 * The PFN range must belong to a single zone.
6248 * Returns zero on success or negative error code. On success all
6249 * pages which PFN is in [start, end) are allocated for the caller and
6250 * need to be freed with free_contig_range().
6252 int alloc_contig_range(unsigned long start
, unsigned long end
,
6253 unsigned migratetype
)
6255 unsigned long outer_start
, outer_end
;
6258 struct compact_control cc
= {
6259 .nr_migratepages
= 0,
6261 .zone
= page_zone(pfn_to_page(start
)),
6262 .mode
= MIGRATE_SYNC
,
6263 .ignore_skip_hint
= true,
6265 INIT_LIST_HEAD(&cc
.migratepages
);
6268 * What we do here is we mark all pageblocks in range as
6269 * MIGRATE_ISOLATE. Because pageblock and max order pages may
6270 * have different sizes, and due to the way page allocator
6271 * work, we align the range to biggest of the two pages so
6272 * that page allocator won't try to merge buddies from
6273 * different pageblocks and change MIGRATE_ISOLATE to some
6274 * other migration type.
6276 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
6277 * migrate the pages from an unaligned range (ie. pages that
6278 * we are interested in). This will put all the pages in
6279 * range back to page allocator as MIGRATE_ISOLATE.
6281 * When this is done, we take the pages in range from page
6282 * allocator removing them from the buddy system. This way
6283 * page allocator will never consider using them.
6285 * This lets us mark the pageblocks back as
6286 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
6287 * aligned range but not in the unaligned, original range are
6288 * put back to page allocator so that buddy can use them.
6291 ret
= start_isolate_page_range(pfn_max_align_down(start
),
6292 pfn_max_align_up(end
), migratetype
,
6297 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
6302 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
6303 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
6304 * more, all pages in [start, end) are free in page allocator.
6305 * What we are going to do is to allocate all pages from
6306 * [start, end) (that is remove them from page allocator).
6308 * The only problem is that pages at the beginning and at the
6309 * end of interesting range may be not aligned with pages that
6310 * page allocator holds, ie. they can be part of higher order
6311 * pages. Because of this, we reserve the bigger range and
6312 * once this is done free the pages we are not interested in.
6314 * We don't have to hold zone->lock here because the pages are
6315 * isolated thus they won't get removed from buddy.
6318 lru_add_drain_all();
6322 outer_start
= start
;
6323 while (!PageBuddy(pfn_to_page(outer_start
))) {
6324 if (++order
>= MAX_ORDER
) {
6328 outer_start
&= ~0UL << order
;
6331 /* Make sure the range is really isolated. */
6332 if (test_pages_isolated(outer_start
, end
, false)) {
6333 pr_warn("alloc_contig_range test_pages_isolated(%lx, %lx) failed\n",
6340 /* Grab isolated pages from freelists. */
6341 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
6347 /* Free head and tail (if any) */
6348 if (start
!= outer_start
)
6349 free_contig_range(outer_start
, start
- outer_start
);
6350 if (end
!= outer_end
)
6351 free_contig_range(end
, outer_end
- end
);
6354 undo_isolate_page_range(pfn_max_align_down(start
),
6355 pfn_max_align_up(end
), migratetype
);
6359 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
6361 unsigned int count
= 0;
6363 for (; nr_pages
--; pfn
++) {
6364 struct page
*page
= pfn_to_page(pfn
);
6366 count
+= page_count(page
) != 1;
6369 WARN(count
!= 0, "%d pages are still in use!\n", count
);
6373 #ifdef CONFIG_MEMORY_HOTPLUG
6375 * The zone indicated has a new number of managed_pages; batch sizes and percpu
6376 * page high values need to be recalulated.
6378 void __meminit
zone_pcp_update(struct zone
*zone
)
6381 mutex_lock(&pcp_batch_high_lock
);
6382 for_each_possible_cpu(cpu
)
6383 pageset_set_high_and_batch(zone
,
6384 per_cpu_ptr(zone
->pageset
, cpu
));
6385 mutex_unlock(&pcp_batch_high_lock
);
6389 void zone_pcp_reset(struct zone
*zone
)
6391 unsigned long flags
;
6393 struct per_cpu_pageset
*pset
;
6395 /* avoid races with drain_pages() */
6396 local_irq_save(flags
);
6397 if (zone
->pageset
!= &boot_pageset
) {
6398 for_each_online_cpu(cpu
) {
6399 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
6400 drain_zonestat(zone
, pset
);
6402 free_percpu(zone
->pageset
);
6403 zone
->pageset
= &boot_pageset
;
6405 local_irq_restore(flags
);
6408 #ifdef CONFIG_MEMORY_HOTREMOVE
6410 * All pages in the range must be isolated before calling this.
6413 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
6419 unsigned long flags
;
6420 /* find the first valid pfn */
6421 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
6426 zone
= page_zone(pfn_to_page(pfn
));
6427 spin_lock_irqsave(&zone
->lock
, flags
);
6429 while (pfn
< end_pfn
) {
6430 if (!pfn_valid(pfn
)) {
6434 page
= pfn_to_page(pfn
);
6436 * The HWPoisoned page may be not in buddy system, and
6437 * page_count() is not 0.
6439 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
6441 SetPageReserved(page
);
6445 BUG_ON(page_count(page
));
6446 BUG_ON(!PageBuddy(page
));
6447 order
= page_order(page
);
6448 #ifdef CONFIG_DEBUG_VM
6449 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
6450 pfn
, 1 << order
, end_pfn
);
6452 list_del(&page
->lru
);
6453 rmv_page_order(page
);
6454 zone
->free_area
[order
].nr_free
--;
6455 for (i
= 0; i
< (1 << order
); i
++)
6456 SetPageReserved((page
+i
));
6457 pfn
+= (1 << order
);
6459 spin_unlock_irqrestore(&zone
->lock
, flags
);
6463 #ifdef CONFIG_MEMORY_FAILURE
6464 bool is_free_buddy_page(struct page
*page
)
6466 struct zone
*zone
= page_zone(page
);
6467 unsigned long pfn
= page_to_pfn(page
);
6468 unsigned long flags
;
6471 spin_lock_irqsave(&zone
->lock
, flags
);
6472 for (order
= 0; order
< MAX_ORDER
; order
++) {
6473 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
6475 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
6478 spin_unlock_irqrestore(&zone
->lock
, flags
);
6480 return order
< MAX_ORDER
;
6484 static const struct trace_print_flags pageflag_names
[] = {
6485 {1UL << PG_locked
, "locked" },
6486 {1UL << PG_error
, "error" },
6487 {1UL << PG_referenced
, "referenced" },
6488 {1UL << PG_uptodate
, "uptodate" },
6489 {1UL << PG_dirty
, "dirty" },
6490 {1UL << PG_lru
, "lru" },
6491 {1UL << PG_active
, "active" },
6492 {1UL << PG_slab
, "slab" },
6493 {1UL << PG_owner_priv_1
, "owner_priv_1" },
6494 {1UL << PG_arch_1
, "arch_1" },
6495 {1UL << PG_reserved
, "reserved" },
6496 {1UL << PG_private
, "private" },
6497 {1UL << PG_private_2
, "private_2" },
6498 {1UL << PG_writeback
, "writeback" },
6499 #ifdef CONFIG_PAGEFLAGS_EXTENDED
6500 {1UL << PG_head
, "head" },
6501 {1UL << PG_tail
, "tail" },
6503 {1UL << PG_compound
, "compound" },
6505 {1UL << PG_swapcache
, "swapcache" },
6506 {1UL << PG_mappedtodisk
, "mappedtodisk" },
6507 {1UL << PG_reclaim
, "reclaim" },
6508 {1UL << PG_swapbacked
, "swapbacked" },
6509 {1UL << PG_unevictable
, "unevictable" },
6511 {1UL << PG_mlocked
, "mlocked" },
6513 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
6514 {1UL << PG_uncached
, "uncached" },
6516 #ifdef CONFIG_MEMORY_FAILURE
6517 {1UL << PG_hwpoison
, "hwpoison" },
6519 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6520 {1UL << PG_compound_lock
, "compound_lock" },
6524 static void dump_page_flags(unsigned long flags
)
6526 const char *delim
= "";
6530 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names
) != __NR_PAGEFLAGS
);
6532 printk(KERN_ALERT
"page flags: %#lx(", flags
);
6534 /* remove zone id */
6535 flags
&= (1UL << NR_PAGEFLAGS
) - 1;
6537 for (i
= 0; i
< ARRAY_SIZE(pageflag_names
) && flags
; i
++) {
6539 mask
= pageflag_names
[i
].mask
;
6540 if ((flags
& mask
) != mask
)
6544 printk("%s%s", delim
, pageflag_names
[i
].name
);
6548 /* check for left over flags */
6550 printk("%s%#lx", delim
, flags
);
6555 void dump_page_badflags(struct page
*page
, const char *reason
,
6556 unsigned long badflags
)
6559 "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
6560 page
, atomic_read(&page
->_count
), page_mapcount(page
),
6561 page
->mapping
, page
->index
);
6562 dump_page_flags(page
->flags
);
6564 pr_alert("page dumped because: %s\n", reason
);
6565 if (page
->flags
& badflags
) {
6566 pr_alert("bad because of flags:\n");
6567 dump_page_flags(page
->flags
& badflags
);
6569 mem_cgroup_print_bad_page(page
);
6572 void dump_page(struct page
*page
, const char *reason
)
6574 dump_page_badflags(page
, reason
, 0);
6576 EXPORT_SYMBOL(dump_page
);