diff options
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 8203 |
1 files changed, 8203 insertions, 0 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c new file mode 100644 index 000000000..9c35403d9 --- /dev/null +++ b/mm/page_alloc.c @@ -0,0 +1,8203 @@ +/* + * linux/mm/page_alloc.c + * + * Manages the free list, the system allocates free pages here. + * Note that kmalloc() lives in slab.c + * + * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds + * Swap reorganised 29.12.95, Stephen Tweedie + * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 + * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999 + * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999 + * Zone balancing, Kanoj Sarcar, SGI, Jan 2000 + * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002 + * (lots of bits borrowed from Ingo Molnar & Andrew Morton) + */ + +#include <linux/stddef.h> +#include <linux/mm.h> +#include <linux/swap.h> +#include <linux/interrupt.h> +#include <linux/pagemap.h> +#include <linux/jiffies.h> +#include <linux/bootmem.h> +#include <linux/memblock.h> +#include <linux/compiler.h> +#include <linux/kernel.h> +#include <linux/kasan.h> +#include <linux/module.h> +#include <linux/suspend.h> +#include <linux/pagevec.h> +#include <linux/blkdev.h> +#include <linux/slab.h> +#include <linux/ratelimit.h> +#include <linux/oom.h> +#include <linux/topology.h> +#include <linux/sysctl.h> +#include <linux/cpu.h> +#include <linux/cpuset.h> +#include <linux/memory_hotplug.h> +#include <linux/nodemask.h> +#include <linux/vmalloc.h> +#include <linux/vmstat.h> +#include <linux/mempolicy.h> +#include <linux/memremap.h> +#include <linux/stop_machine.h> +#include <linux/sort.h> +#include <linux/pfn.h> +#include <linux/backing-dev.h> +#include <linux/fault-inject.h> +#include <linux/page-isolation.h> +#include <linux/page_ext.h> +#include <linux/debugobjects.h> +#include <linux/kmemleak.h> +#include <linux/compaction.h> +#include <trace/events/kmem.h> +#include <trace/events/oom.h> +#include <linux/prefetch.h> +#include <linux/mm_inline.h> +#include <linux/migrate.h> +#include <linux/hugetlb.h> +#include <linux/sched/rt.h> +#include <linux/sched/mm.h> +#include <linux/page_owner.h> +#include <linux/kthread.h> +#include <linux/memcontrol.h> +#include <linux/ftrace.h> +#include <linux/lockdep.h> +#include <linux/nmi.h> +#include <linux/khugepaged.h> + +#include <asm/sections.h> +#include <asm/tlbflush.h> +#include <asm/div64.h> +#include "internal.h" + +/* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */ +static DEFINE_MUTEX(pcp_batch_high_lock); +#define MIN_PERCPU_PAGELIST_FRACTION (8) + +#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID +DEFINE_PER_CPU(int, numa_node); +EXPORT_PER_CPU_SYMBOL(numa_node); +#endif + +DEFINE_STATIC_KEY_TRUE(vm_numa_stat_key); + +#ifdef CONFIG_HAVE_MEMORYLESS_NODES +/* + * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly. + * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined. + * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem() + * defined in <linux/topology.h>. + */ +DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */ +EXPORT_PER_CPU_SYMBOL(_numa_mem_); +int _node_numa_mem_[MAX_NUMNODES]; +#endif + +/* work_structs for global per-cpu drains */ +DEFINE_MUTEX(pcpu_drain_mutex); +DEFINE_PER_CPU(struct work_struct, pcpu_drain); + +#ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY +volatile unsigned long latent_entropy __latent_entropy; +EXPORT_SYMBOL(latent_entropy); +#endif + +/* + * Array of node states. + */ +nodemask_t node_states[NR_NODE_STATES] __read_mostly = { + [N_POSSIBLE] = NODE_MASK_ALL, + [N_ONLINE] = { { [0] = 1UL } }, +#ifndef CONFIG_NUMA + [N_NORMAL_MEMORY] = { { [0] = 1UL } }, +#ifdef CONFIG_HIGHMEM + [N_HIGH_MEMORY] = { { [0] = 1UL } }, +#endif + [N_MEMORY] = { { [0] = 1UL } }, + [N_CPU] = { { [0] = 1UL } }, +#endif /* NUMA */ +}; +EXPORT_SYMBOL(node_states); + +/* Protect totalram_pages and zone->managed_pages */ +static DEFINE_SPINLOCK(managed_page_count_lock); + +unsigned long totalram_pages __read_mostly; +unsigned long totalreserve_pages __read_mostly; +unsigned long totalcma_pages __read_mostly; + +int percpu_pagelist_fraction; +gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK; + +/* + * A cached value of the page's pageblock's migratetype, used when the page is + * put on a pcplist. Used to avoid the pageblock migratetype lookup when + * freeing from pcplists in most cases, at the cost of possibly becoming stale. + * Also the migratetype set in the page does not necessarily match the pcplist + * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any + * other index - this ensures that it will be put on the correct CMA freelist. + */ +static inline int get_pcppage_migratetype(struct page *page) +{ + return page->index; +} + +static inline void set_pcppage_migratetype(struct page *page, int migratetype) +{ + page->index = migratetype; +} + +#ifdef CONFIG_PM_SLEEP +/* + * The following functions are used by the suspend/hibernate code to temporarily + * change gfp_allowed_mask in order to avoid using I/O during memory allocations + * while devices are suspended. To avoid races with the suspend/hibernate code, + * they should always be called with system_transition_mutex held + * (gfp_allowed_mask also should only be modified with system_transition_mutex + * held, unless the suspend/hibernate code is guaranteed not to run in parallel + * with that modification). + */ + +static gfp_t saved_gfp_mask; + +void pm_restore_gfp_mask(void) +{ + WARN_ON(!mutex_is_locked(&system_transition_mutex)); + if (saved_gfp_mask) { + gfp_allowed_mask = saved_gfp_mask; + saved_gfp_mask = 0; + } +} + +void pm_restrict_gfp_mask(void) +{ + WARN_ON(!mutex_is_locked(&system_transition_mutex)); + WARN_ON(saved_gfp_mask); + saved_gfp_mask = gfp_allowed_mask; + gfp_allowed_mask &= ~(__GFP_IO | __GFP_FS); +} + +bool pm_suspended_storage(void) +{ + if ((gfp_allowed_mask & (__GFP_IO | __GFP_FS)) == (__GFP_IO | __GFP_FS)) + return false; + return true; +} +#endif /* CONFIG_PM_SLEEP */ + +#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE +unsigned int pageblock_order __read_mostly; +#endif + +static void __free_pages_ok(struct page *page, unsigned int order); + +/* + * results with 256, 32 in the lowmem_reserve sysctl: + * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high) + * 1G machine -> (16M dma, 784M normal, 224M high) + * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA + * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL + * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA + * + * TBD: should special case ZONE_DMA32 machines here - in those we normally + * don't need any ZONE_NORMAL reservation + */ +int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES] = { +#ifdef CONFIG_ZONE_DMA + [ZONE_DMA] = 256, +#endif +#ifdef CONFIG_ZONE_DMA32 + [ZONE_DMA32] = 256, +#endif + [ZONE_NORMAL] = 32, +#ifdef CONFIG_HIGHMEM + [ZONE_HIGHMEM] = 0, +#endif + [ZONE_MOVABLE] = 0, +}; + +EXPORT_SYMBOL(totalram_pages); + +static char * const zone_names[MAX_NR_ZONES] = { +#ifdef CONFIG_ZONE_DMA + "DMA", +#endif +#ifdef CONFIG_ZONE_DMA32 + "DMA32", +#endif + "Normal", +#ifdef CONFIG_HIGHMEM + "HighMem", +#endif + "Movable", +#ifdef CONFIG_ZONE_DEVICE + "Device", +#endif +}; + +char * const migratetype_names[MIGRATE_TYPES] = { + "Unmovable", + "Movable", + "Reclaimable", + "HighAtomic", +#ifdef CONFIG_CMA + "CMA", +#endif +#ifdef CONFIG_MEMORY_ISOLATION + "Isolate", +#endif +}; + +compound_page_dtor * const compound_page_dtors[] = { + NULL, + free_compound_page, +#ifdef CONFIG_HUGETLB_PAGE + free_huge_page, +#endif +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + free_transhuge_page, +#endif +}; + +int min_free_kbytes = 1024; +int user_min_free_kbytes = -1; +int watermark_scale_factor = 10; + +static unsigned long nr_kernel_pages __meminitdata; +static unsigned long nr_all_pages __meminitdata; +static unsigned long dma_reserve __meminitdata; + +#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP +static unsigned long arch_zone_lowest_possible_pfn[MAX_NR_ZONES] __meminitdata; +static unsigned long arch_zone_highest_possible_pfn[MAX_NR_ZONES] __meminitdata; +static unsigned long required_kernelcore __initdata; +static unsigned long required_kernelcore_percent __initdata; +static unsigned long required_movablecore __initdata; +static unsigned long required_movablecore_percent __initdata; +static unsigned long zone_movable_pfn[MAX_NUMNODES] __meminitdata; +static bool mirrored_kernelcore __meminitdata; + +/* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */ +int movable_zone; +EXPORT_SYMBOL(movable_zone); +#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ + +#if MAX_NUMNODES > 1 +int nr_node_ids __read_mostly = MAX_NUMNODES; +int nr_online_nodes __read_mostly = 1; +EXPORT_SYMBOL(nr_node_ids); +EXPORT_SYMBOL(nr_online_nodes); +#endif + +int page_group_by_mobility_disabled __read_mostly; + +#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT +/* + * During boot we initialize deferred pages on-demand, as needed, but once + * page_alloc_init_late() has finished, the deferred pages are all initialized, + * and we can permanently disable that path. + */ +static DEFINE_STATIC_KEY_TRUE(deferred_pages); + +/* + * Calling kasan_free_pages() only after deferred memory initialization + * has completed. Poisoning pages during deferred memory init will greatly + * lengthen the process and cause problem in large memory systems as the + * deferred pages initialization is done with interrupt disabled. + * + * Assuming that there will be no reference to those newly initialized + * pages before they are ever allocated, this should have no effect on + * KASAN memory tracking as the poison will be properly inserted at page + * allocation time. The only corner case is when pages are allocated by + * on-demand allocation and then freed again before the deferred pages + * initialization is done, but this is not likely to happen. + */ +static inline void kasan_free_nondeferred_pages(struct page *page, int order) +{ + if (!static_branch_unlikely(&deferred_pages)) + kasan_free_pages(page, order); +} + +/* Returns true if the struct page for the pfn is uninitialised */ +static inline bool __meminit early_page_uninitialised(unsigned long pfn) +{ + int nid = early_pfn_to_nid(pfn); + + if (node_online(nid) && pfn >= NODE_DATA(nid)->first_deferred_pfn) + return true; + + return false; +} + +/* + * Returns false when the remaining initialisation should be deferred until + * later in the boot cycle when it can be parallelised. + */ +static inline bool update_defer_init(pg_data_t *pgdat, + unsigned long pfn, unsigned long zone_end, + unsigned long *nr_initialised) +{ + /* Always populate low zones for address-constrained allocations */ + if (zone_end < pgdat_end_pfn(pgdat)) + return true; + (*nr_initialised)++; + if ((*nr_initialised > pgdat->static_init_pgcnt) && + (pfn & (PAGES_PER_SECTION - 1)) == 0) { + pgdat->first_deferred_pfn = pfn; + return false; + } + + return true; +} +#else +#define kasan_free_nondeferred_pages(p, o) kasan_free_pages(p, o) + +static inline bool early_page_uninitialised(unsigned long pfn) +{ + return false; +} + +static inline bool update_defer_init(pg_data_t *pgdat, + unsigned long pfn, unsigned long zone_end, + unsigned long *nr_initialised) +{ + return true; +} +#endif + +/* Return a pointer to the bitmap storing bits affecting a block of pages */ +static inline unsigned long *get_pageblock_bitmap(struct page *page, + unsigned long pfn) +{ +#ifdef CONFIG_SPARSEMEM + return __pfn_to_section(pfn)->pageblock_flags; +#else + return page_zone(page)->pageblock_flags; +#endif /* CONFIG_SPARSEMEM */ +} + +static inline int pfn_to_bitidx(struct page *page, unsigned long pfn) +{ +#ifdef CONFIG_SPARSEMEM + pfn &= (PAGES_PER_SECTION-1); + return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; +#else + pfn = pfn - round_down(page_zone(page)->zone_start_pfn, pageblock_nr_pages); + return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; +#endif /* CONFIG_SPARSEMEM */ +} + +/** + * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages + * @page: The page within the block of interest + * @pfn: The target page frame number + * @end_bitidx: The last bit of interest to retrieve + * @mask: mask of bits that the caller is interested in + * + * Return: pageblock_bits flags + */ +static __always_inline unsigned long __get_pfnblock_flags_mask(struct page *page, + unsigned long pfn, + unsigned long end_bitidx, + unsigned long mask) +{ + unsigned long *bitmap; + unsigned long bitidx, word_bitidx; + unsigned long word; + + bitmap = get_pageblock_bitmap(page, pfn); + bitidx = pfn_to_bitidx(page, pfn); + word_bitidx = bitidx / BITS_PER_LONG; + bitidx &= (BITS_PER_LONG-1); + + word = bitmap[word_bitidx]; + bitidx += end_bitidx; + return (word >> (BITS_PER_LONG - bitidx - 1)) & mask; +} + +unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn, + unsigned long end_bitidx, + unsigned long mask) +{ + return __get_pfnblock_flags_mask(page, pfn, end_bitidx, mask); +} + +static __always_inline int get_pfnblock_migratetype(struct page *page, unsigned long pfn) +{ + return __get_pfnblock_flags_mask(page, pfn, PB_migrate_end, MIGRATETYPE_MASK); +} + +/** + * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages + * @page: The page within the block of interest + * @flags: The flags to set + * @pfn: The target page frame number + * @end_bitidx: The last bit of interest + * @mask: mask of bits that the caller is interested in + */ +void set_pfnblock_flags_mask(struct page *page, unsigned long flags, + unsigned long pfn, + unsigned long end_bitidx, + unsigned long mask) +{ + unsigned long *bitmap; + unsigned long bitidx, word_bitidx; + unsigned long old_word, word; + + BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4); + + bitmap = get_pageblock_bitmap(page, pfn); + bitidx = pfn_to_bitidx(page, pfn); + word_bitidx = bitidx / BITS_PER_LONG; + bitidx &= (BITS_PER_LONG-1); + + VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page); + + bitidx += end_bitidx; + mask <<= (BITS_PER_LONG - bitidx - 1); + flags <<= (BITS_PER_LONG - bitidx - 1); + + word = READ_ONCE(bitmap[word_bitidx]); + for (;;) { + old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags); + if (word == old_word) + break; + word = old_word; + } +} + +void set_pageblock_migratetype(struct page *page, int migratetype) +{ + if (unlikely(page_group_by_mobility_disabled && + migratetype < MIGRATE_PCPTYPES)) + migratetype = MIGRATE_UNMOVABLE; + + set_pageblock_flags_group(page, (unsigned long)migratetype, + PB_migrate, PB_migrate_end); +} + +#ifdef CONFIG_DEBUG_VM +static int page_outside_zone_boundaries(struct zone *zone, struct page *page) +{ + int ret = 0; + unsigned seq; + unsigned long pfn = page_to_pfn(page); + unsigned long sp, start_pfn; + + do { + seq = zone_span_seqbegin(zone); + start_pfn = zone->zone_start_pfn; + sp = zone->spanned_pages; + if (!zone_spans_pfn(zone, pfn)) + ret = 1; + } while (zone_span_seqretry(zone, seq)); + + if (ret) + pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n", + pfn, zone_to_nid(zone), zone->name, + start_pfn, start_pfn + sp); + + return ret; +} + +static int page_is_consistent(struct zone *zone, struct page *page) +{ + if (!pfn_valid_within(page_to_pfn(page))) + return 0; + if (zone != page_zone(page)) + return 0; + + return 1; +} +/* + * Temporary debugging check for pages not lying within a given zone. + */ +static int __maybe_unused bad_range(struct zone *zone, struct page *page) +{ + if (page_outside_zone_boundaries(zone, page)) + return 1; + if (!page_is_consistent(zone, page)) + return 1; + + return 0; +} +#else +static inline int __maybe_unused bad_range(struct zone *zone, struct page *page) +{ + return 0; +} +#endif + +static void bad_page(struct page *page, const char *reason, + unsigned long bad_flags) +{ + static unsigned long resume; + static unsigned long nr_shown; + static unsigned long nr_unshown; + + /* + * Allow a burst of 60 reports, then keep quiet for that minute; + * or allow a steady drip of one report per second. + */ + if (nr_shown == 60) { + if (time_before(jiffies, resume)) { + nr_unshown++; + goto out; + } + if (nr_unshown) { + pr_alert( + "BUG: Bad page state: %lu messages suppressed\n", + nr_unshown); + nr_unshown = 0; + } + nr_shown = 0; + } + if (nr_shown++ == 0) + resume = jiffies + 60 * HZ; + + pr_alert("BUG: Bad page state in process %s pfn:%05lx\n", + current->comm, page_to_pfn(page)); + __dump_page(page, reason); + bad_flags &= page->flags; + if (bad_flags) + pr_alert("bad because of flags: %#lx(%pGp)\n", + bad_flags, &bad_flags); + dump_page_owner(page); + + print_modules(); + dump_stack(); +out: + /* Leave bad fields for debug, except PageBuddy could make trouble */ + page_mapcount_reset(page); /* remove PageBuddy */ + add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); +} + +/* + * Higher-order pages are called "compound pages". They are structured thusly: + * + * The first PAGE_SIZE page is called the "head page" and have PG_head set. + * + * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded + * in bit 0 of page->compound_head. The rest of bits is pointer to head page. + * + * The first tail page's ->compound_dtor holds the offset in array of compound + * page destructors. See compound_page_dtors. + * + * The first tail page's ->compound_order holds the order of allocation. + * This usage means that zero-order pages may not be compound. + */ + +void free_compound_page(struct page *page) +{ + __free_pages_ok(page, compound_order(page)); +} + +void prep_compound_page(struct page *page, unsigned int order) +{ + int i; + int nr_pages = 1 << order; + + set_compound_page_dtor(page, COMPOUND_PAGE_DTOR); + set_compound_order(page, order); + __SetPageHead(page); + for (i = 1; i < nr_pages; i++) { + struct page *p = page + i; + set_page_count(p, 0); + p->mapping = TAIL_MAPPING; + set_compound_head(p, page); + } + atomic_set(compound_mapcount_ptr(page), -1); +} + +#ifdef CONFIG_DEBUG_PAGEALLOC +unsigned int _debug_guardpage_minorder; +bool _debug_pagealloc_enabled __read_mostly + = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT); +EXPORT_SYMBOL(_debug_pagealloc_enabled); +bool _debug_guardpage_enabled __read_mostly; + +static int __init early_debug_pagealloc(char *buf) +{ + if (!buf) + return -EINVAL; + return kstrtobool(buf, &_debug_pagealloc_enabled); +} +early_param("debug_pagealloc", early_debug_pagealloc); + +static bool need_debug_guardpage(void) +{ + /* If we don't use debug_pagealloc, we don't need guard page */ + if (!debug_pagealloc_enabled()) + return false; + + if (!debug_guardpage_minorder()) + return false; + + return true; +} + +static void init_debug_guardpage(void) +{ + if (!debug_pagealloc_enabled()) + return; + + if (!debug_guardpage_minorder()) + return; + + _debug_guardpage_enabled = true; +} + +struct page_ext_operations debug_guardpage_ops = { + .need = need_debug_guardpage, + .init = init_debug_guardpage, +}; + +static int __init debug_guardpage_minorder_setup(char *buf) +{ + unsigned long res; + + if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) { + pr_err("Bad debug_guardpage_minorder value\n"); + return 0; + } + _debug_guardpage_minorder = res; + pr_info("Setting debug_guardpage_minorder to %lu\n", res); + return 0; +} +early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup); + +static inline bool set_page_guard(struct zone *zone, struct page *page, + unsigned int order, int migratetype) +{ + struct page_ext *page_ext; + + if (!debug_guardpage_enabled()) + return false; + + if (order >= debug_guardpage_minorder()) + return false; + + page_ext = lookup_page_ext(page); + if (unlikely(!page_ext)) + return false; + + __set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags); + + INIT_LIST_HEAD(&page->lru); + set_page_private(page, order); + /* Guard pages are not available for any usage */ + __mod_zone_freepage_state(zone, -(1 << order), migratetype); + + return true; +} + +static inline void clear_page_guard(struct zone *zone, struct page *page, + unsigned int order, int migratetype) +{ + struct page_ext *page_ext; + + if (!debug_guardpage_enabled()) + return; + + page_ext = lookup_page_ext(page); + if (unlikely(!page_ext)) + return; + + __clear_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags); + + set_page_private(page, 0); + if (!is_migrate_isolate(migratetype)) + __mod_zone_freepage_state(zone, (1 << order), migratetype); +} +#else +struct page_ext_operations debug_guardpage_ops; +static inline bool set_page_guard(struct zone *zone, struct page *page, + unsigned int order, int migratetype) { return false; } +static inline void clear_page_guard(struct zone *zone, struct page *page, + unsigned int order, int migratetype) {} +#endif + +static inline void set_page_order(struct page *page, unsigned int order) +{ + set_page_private(page, order); + __SetPageBuddy(page); +} + +static inline void rmv_page_order(struct page *page) +{ + __ClearPageBuddy(page); + set_page_private(page, 0); +} + +/* + * This function checks whether a page is free && is the buddy + * we can coalesce a page and its buddy if + * (a) the buddy is not in a hole (check before calling!) && + * (b) the buddy is in the buddy system && + * (c) a page and its buddy have the same order && + * (d) a page and its buddy are in the same zone. + * + * For recording whether a page is in the buddy system, we set PageBuddy. + * Setting, clearing, and testing PageBuddy is serialized by zone->lock. + * + * For recording page's order, we use page_private(page). + */ +static inline int page_is_buddy(struct page *page, struct page *buddy, + unsigned int order) +{ + if (page_is_guard(buddy) && page_order(buddy) == order) { + if (page_zone_id(page) != page_zone_id(buddy)) + return 0; + + VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); + + return 1; + } + + if (PageBuddy(buddy) && page_order(buddy) == order) { + /* + * zone check is done late to avoid uselessly + * calculating zone/node ids for pages that could + * never merge. + */ + if (page_zone_id(page) != page_zone_id(buddy)) + return 0; + + VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); + + return 1; + } + return 0; +} + +/* + * Freeing function for a buddy system allocator. + * + * The concept of a buddy system is to maintain direct-mapped table + * (containing bit values) for memory blocks of various "orders". + * The bottom level table contains the map for the smallest allocatable + * units of memory (here, pages), and each level above it describes + * pairs of units from the levels below, hence, "buddies". + * At a high level, all that happens here is marking the table entry + * at the bottom level available, and propagating the changes upward + * as necessary, plus some accounting needed to play nicely with other + * parts of the VM system. + * At each level, we keep a list of pages, which are heads of continuous + * free pages of length of (1 << order) and marked with PageBuddy. + * Page's order is recorded in page_private(page) field. + * So when we are allocating or freeing one, we can derive the state of the + * other. That is, if we allocate a small block, and both were + * free, the remainder of the region must be split into blocks. + * If a block is freed, and its buddy is also free, then this + * triggers coalescing into a block of larger size. + * + * -- nyc + */ + +static inline void __free_one_page(struct page *page, + unsigned long pfn, + struct zone *zone, unsigned int order, + int migratetype) +{ + unsigned long combined_pfn; + unsigned long uninitialized_var(buddy_pfn); + struct page *buddy; + unsigned int max_order; + + max_order = min_t(unsigned int, MAX_ORDER - 1, pageblock_order); + + VM_BUG_ON(!zone_is_initialized(zone)); + VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page); + + VM_BUG_ON(migratetype == -1); + if (likely(!is_migrate_isolate(migratetype))) + __mod_zone_freepage_state(zone, 1 << order, migratetype); + + VM_BUG_ON_PAGE(pfn & ((1 << order) - 1), page); + VM_BUG_ON_PAGE(bad_range(zone, page), page); + +continue_merging: + while (order < max_order) { + buddy_pfn = __find_buddy_pfn(pfn, order); + buddy = page + (buddy_pfn - pfn); + + if (!pfn_valid_within(buddy_pfn)) + goto done_merging; + if (!page_is_buddy(page, buddy, order)) + goto done_merging; + /* + * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page, + * merge with it and move up one order. + */ + if (page_is_guard(buddy)) { + clear_page_guard(zone, buddy, order, migratetype); + } else { + list_del(&buddy->lru); + zone->free_area[order].nr_free--; + rmv_page_order(buddy); + } + combined_pfn = buddy_pfn & pfn; + page = page + (combined_pfn - pfn); + pfn = combined_pfn; + order++; + } + if (order < MAX_ORDER - 1) { + /* If we are here, it means order is >= pageblock_order. + * We want to prevent merge between freepages on isolate + * pageblock and normal pageblock. Without this, pageblock + * isolation could cause incorrect freepage or CMA accounting. + * + * We don't want to hit this code for the more frequent + * low-order merging. + */ + if (unlikely(has_isolate_pageblock(zone))) { + int buddy_mt; + + buddy_pfn = __find_buddy_pfn(pfn, order); + buddy = page + (buddy_pfn - pfn); + buddy_mt = get_pageblock_migratetype(buddy); + + if (migratetype != buddy_mt + && (is_migrate_isolate(migratetype) || + is_migrate_isolate(buddy_mt))) + goto done_merging; + } + max_order = order + 1; + goto continue_merging; + } + +done_merging: + set_page_order(page, order); + + /* + * If this is not the largest possible page, check if the buddy + * of the next-highest order is free. If it is, it's possible + * that pages are being freed that will coalesce soon. In case, + * that is happening, add the free page to the tail of the list + * so it's less likely to be used soon and more likely to be merged + * as a higher order page + */ + if ((order < MAX_ORDER-2) && pfn_valid_within(buddy_pfn)) { + struct page *higher_page, *higher_buddy; + combined_pfn = buddy_pfn & pfn; + higher_page = page + (combined_pfn - pfn); + buddy_pfn = __find_buddy_pfn(combined_pfn, order + 1); + higher_buddy = higher_page + (buddy_pfn - combined_pfn); + if (pfn_valid_within(buddy_pfn) && + page_is_buddy(higher_page, higher_buddy, order + 1)) { + list_add_tail(&page->lru, + &zone->free_area[order].free_list[migratetype]); + goto out; + } + } + + list_add(&page->lru, &zone->free_area[order].free_list[migratetype]); +out: + zone->free_area[order].nr_free++; +} + +/* + * A bad page could be due to a number of fields. Instead of multiple branches, + * try and check multiple fields with one check. The caller must do a detailed + * check if necessary. + */ +static inline bool page_expected_state(struct page *page, + unsigned long check_flags) +{ + if (unlikely(atomic_read(&page->_mapcount) != -1)) + return false; + + if (unlikely((unsigned long)page->mapping | + page_ref_count(page) | +#ifdef CONFIG_MEMCG + (unsigned long)page->mem_cgroup | +#endif + (page->flags & check_flags))) + return false; + + return true; +} + +static void free_pages_check_bad(struct page *page) +{ + const char *bad_reason; + unsigned long bad_flags; + + bad_reason = NULL; + bad_flags = 0; + + if (unlikely(atomic_read(&page->_mapcount) != -1)) + bad_reason = "nonzero mapcount"; + if (unlikely(page->mapping != NULL)) + bad_reason = "non-NULL mapping"; + if (unlikely(page_ref_count(page) != 0)) + bad_reason = "nonzero _refcount"; + if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) { + bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set"; + bad_flags = PAGE_FLAGS_CHECK_AT_FREE; + } +#ifdef CONFIG_MEMCG + if (unlikely(page->mem_cgroup)) + bad_reason = "page still charged to cgroup"; +#endif + bad_page(page, bad_reason, bad_flags); +} + +static inline int free_pages_check(struct page *page) +{ + if (likely(page_expected_state(page, PAGE_FLAGS_CHECK_AT_FREE))) + return 0; + + /* Something has gone sideways, find it */ + free_pages_check_bad(page); + return 1; +} + +static int free_tail_pages_check(struct page *head_page, struct page *page) +{ + int ret = 1; + + /* + * We rely page->lru.next never has bit 0 set, unless the page + * is PageTail(). Let's make sure that's true even for poisoned ->lru. + */ + BUILD_BUG_ON((unsigned long)LIST_POISON1 & 1); + + if (!IS_ENABLED(CONFIG_DEBUG_VM)) { + ret = 0; + goto out; + } + switch (page - head_page) { + case 1: + /* the first tail page: ->mapping may be compound_mapcount() */ + if (unlikely(compound_mapcount(page))) { + bad_page(page, "nonzero compound_mapcount", 0); + goto out; + } + break; + case 2: + /* + * the second tail page: ->mapping is + * deferred_list.next -- ignore value. + */ + break; + default: + if (page->mapping != TAIL_MAPPING) { + bad_page(page, "corrupted mapping in tail page", 0); + goto out; + } + break; + } + if (unlikely(!PageTail(page))) { + bad_page(page, "PageTail not set", 0); + goto out; + } + if (unlikely(compound_head(page) != head_page)) { + bad_page(page, "compound_head not consistent", 0); + goto out; + } + ret = 0; +out: + page->mapping = NULL; + clear_compound_head(page); + return ret; +} + +static __always_inline bool free_pages_prepare(struct page *page, + unsigned int order, bool check_free) +{ + int bad = 0; + + VM_BUG_ON_PAGE(PageTail(page), page); + + trace_mm_page_free(page, order); + + /* + * Check tail pages before head page information is cleared to + * avoid checking PageCompound for order-0 pages. + */ + if (unlikely(order)) { + bool compound = PageCompound(page); + int i; + + VM_BUG_ON_PAGE(compound && compound_order(page) != order, page); + + if (compound) + ClearPageDoubleMap(page); + for (i = 1; i < (1 << order); i++) { + if (compound) + bad += free_tail_pages_check(page, page + i); + if (unlikely(free_pages_check(page + i))) { + bad++; + continue; + } + (page + i)->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; + } + } + if (PageMappingFlags(page)) + page->mapping = NULL; + if (memcg_kmem_enabled() && PageKmemcg(page)) + memcg_kmem_uncharge(page, order); + if (check_free) + bad += free_pages_check(page); + if (bad) + return false; + + page_cpupid_reset_last(page); + page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; + reset_page_owner(page, order); + + if (!PageHighMem(page)) { + debug_check_no_locks_freed(page_address(page), + PAGE_SIZE << order); + debug_check_no_obj_freed(page_address(page), + PAGE_SIZE << order); + } + arch_free_page(page, order); + kernel_poison_pages(page, 1 << order, 0); + kernel_map_pages(page, 1 << order, 0); + kasan_free_nondeferred_pages(page, order); + + return true; +} + +#ifdef CONFIG_DEBUG_VM +static inline bool free_pcp_prepare(struct page *page) +{ + return free_pages_prepare(page, 0, true); +} + +static inline bool bulkfree_pcp_prepare(struct page *page) +{ + return false; +} +#else +static bool free_pcp_prepare(struct page *page) +{ + return free_pages_prepare(page, 0, false); +} + +static bool bulkfree_pcp_prepare(struct page *page) +{ + return free_pages_check(page); +} +#endif /* CONFIG_DEBUG_VM */ + +static inline void prefetch_buddy(struct page *page) +{ + unsigned long pfn = page_to_pfn(page); + unsigned long buddy_pfn = __find_buddy_pfn(pfn, 0); + struct page *buddy = page + (buddy_pfn - pfn); + + prefetch(buddy); +} + +/* + * Frees a number of pages from the PCP lists + * Assumes all pages on list are in same zone, and of same order. + * count is the number of pages to free. + * + * If the zone was previously in an "all pages pinned" state then look to + * see if this freeing clears that state. + * + * And clear the zone's pages_scanned counter, to hold off the "all pages are + * pinned" detection logic. + */ +static void free_pcppages_bulk(struct zone *zone, int count, + struct per_cpu_pages *pcp) +{ + int migratetype = 0; + int batch_free = 0; + int prefetch_nr = 0; + bool isolated_pageblocks; + struct page *page, *tmp; + LIST_HEAD(head); + + /* + * Ensure proper count is passed which otherwise would stuck in the + * below while (list_empty(list)) loop. + */ + count = min(pcp->count, count); + while (count) { + struct list_head *list; + + /* + * Remove pages from lists in a round-robin fashion. A + * batch_free count is maintained that is incremented when an + * empty list is encountered. This is so more pages are freed + * off fuller lists instead of spinning excessively around empty + * lists + */ + do { + batch_free++; + if (++migratetype == MIGRATE_PCPTYPES) + migratetype = 0; + list = &pcp->lists[migratetype]; + } while (list_empty(list)); + + /* This is the only non-empty list. Free them all. */ + if (batch_free == MIGRATE_PCPTYPES) + batch_free = count; + + do { + page = list_last_entry(list, struct page, lru); + /* must delete to avoid corrupting pcp list */ + list_del(&page->lru); + pcp->count--; + + if (bulkfree_pcp_prepare(page)) + continue; + + list_add_tail(&page->lru, &head); + + /* + * We are going to put the page back to the global + * pool, prefetch its buddy to speed up later access + * under zone->lock. It is believed the overhead of + * an additional test and calculating buddy_pfn here + * can be offset by reduced memory latency later. To + * avoid excessive prefetching due to large count, only + * prefetch buddy for the first pcp->batch nr of pages. + */ + if (prefetch_nr++ < pcp->batch) + prefetch_buddy(page); + } while (--count && --batch_free && !list_empty(list)); + } + + spin_lock(&zone->lock); + isolated_pageblocks = has_isolate_pageblock(zone); + + /* + * Use safe version since after __free_one_page(), + * page->lru.next will not point to original list. + */ + list_for_each_entry_safe(page, tmp, &head, lru) { + int mt = get_pcppage_migratetype(page); + /* MIGRATE_ISOLATE page should not go to pcplists */ + VM_BUG_ON_PAGE(is_migrate_isolate(mt), page); + /* Pageblock could have been isolated meanwhile */ + if (unlikely(isolated_pageblocks)) + mt = get_pageblock_migratetype(page); + + __free_one_page(page, page_to_pfn(page), zone, 0, mt); + trace_mm_page_pcpu_drain(page, 0, mt); + } + spin_unlock(&zone->lock); +} + +static void free_one_page(struct zone *zone, + struct page *page, unsigned long pfn, + unsigned int order, + int migratetype) +{ + spin_lock(&zone->lock); + if (unlikely(has_isolate_pageblock(zone) || + is_migrate_isolate(migratetype))) { + migratetype = get_pfnblock_migratetype(page, pfn); + } + __free_one_page(page, pfn, zone, order, migratetype); + spin_unlock(&zone->lock); +} + +static void __meminit __init_single_page(struct page *page, unsigned long pfn, + unsigned long zone, int nid) +{ + mm_zero_struct_page(page); + set_page_links(page, zone, nid, pfn); + init_page_count(page); + page_mapcount_reset(page); + page_cpupid_reset_last(page); + + INIT_LIST_HEAD(&page->lru); +#ifdef WANT_PAGE_VIRTUAL + /* The shift won't overflow because ZONE_NORMAL is below 4G. */ + if (!is_highmem_idx(zone)) + set_page_address(page, __va(pfn << PAGE_SHIFT)); +#endif +} + +#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT +static void __meminit init_reserved_page(unsigned long pfn) +{ + pg_data_t *pgdat; + int nid, zid; + + if (!early_page_uninitialised(pfn)) + return; + + nid = early_pfn_to_nid(pfn); + pgdat = NODE_DATA(nid); + + for (zid = 0; zid < MAX_NR_ZONES; zid++) { + struct zone *zone = &pgdat->node_zones[zid]; + + if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone)) + break; + } + __init_single_page(pfn_to_page(pfn), pfn, zid, nid); +} +#else +static inline void init_reserved_page(unsigned long pfn) +{ +} +#endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ + +/* + * Initialised pages do not have PageReserved set. This function is + * called for each range allocated by the bootmem allocator and + * marks the pages PageReserved. The remaining valid pages are later + * sent to the buddy page allocator. + */ +void __meminit reserve_bootmem_region(phys_addr_t start, phys_addr_t end) +{ + unsigned long start_pfn = PFN_DOWN(start); + unsigned long end_pfn = PFN_UP(end); + + for (; start_pfn < end_pfn; start_pfn++) { + if (pfn_valid(start_pfn)) { + struct page *page = pfn_to_page(start_pfn); + + init_reserved_page(start_pfn); + + /* Avoid false-positive PageTail() */ + INIT_LIST_HEAD(&page->lru); + + SetPageReserved(page); + } + } +} + +static void __free_pages_ok(struct page *page, unsigned int order) +{ + unsigned long flags; + int migratetype; + unsigned long pfn = page_to_pfn(page); + + if (!free_pages_prepare(page, order, true)) + return; + + migratetype = get_pfnblock_migratetype(page, pfn); + local_irq_save(flags); + __count_vm_events(PGFREE, 1 << order); + free_one_page(page_zone(page), page, pfn, order, migratetype); + local_irq_restore(flags); +} + +static void __init __free_pages_boot_core(struct page *page, unsigned int order) +{ + unsigned int nr_pages = 1 << order; + struct page *p = page; + unsigned int loop; + + prefetchw(p); + for (loop = 0; loop < (nr_pages - 1); loop++, p++) { + prefetchw(p + 1); + __ClearPageReserved(p); + set_page_count(p, 0); + } + __ClearPageReserved(p); + set_page_count(p, 0); + + page_zone(page)->managed_pages += nr_pages; + set_page_refcounted(page); + __free_pages(page, order); +} + +#if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \ + defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) + +static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata; + +int __meminit early_pfn_to_nid(unsigned long pfn) +{ + static DEFINE_SPINLOCK(early_pfn_lock); + int nid; + + spin_lock(&early_pfn_lock); + nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache); + if (nid < 0) + nid = first_online_node; + spin_unlock(&early_pfn_lock); + + return nid; +} +#endif + +#ifdef CONFIG_NODES_SPAN_OTHER_NODES +static inline bool __meminit __maybe_unused +meminit_pfn_in_nid(unsigned long pfn, int node, + struct mminit_pfnnid_cache *state) +{ + int nid; + + nid = __early_pfn_to_nid(pfn, state); + if (nid >= 0 && nid != node) + return false; + return true; +} + +/* Only safe to use early in boot when initialisation is single-threaded */ +static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node) +{ + return meminit_pfn_in_nid(pfn, node, &early_pfnnid_cache); +} + +#else + +static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node) +{ + return true; +} +static inline bool __meminit __maybe_unused +meminit_pfn_in_nid(unsigned long pfn, int node, + struct mminit_pfnnid_cache *state) +{ + return true; +} +#endif + + +void __init __free_pages_bootmem(struct page *page, unsigned long pfn, + unsigned int order) +{ + if (early_page_uninitialised(pfn)) + return; + return __free_pages_boot_core(page, order); +} + +/* + * Check that the whole (or subset of) a pageblock given by the interval of + * [start_pfn, end_pfn) is valid and within the same zone, before scanning it + * with the migration of free compaction scanner. The scanners then need to + * use only pfn_valid_within() check for arches that allow holes within + * pageblocks. + * + * Return struct page pointer of start_pfn, or NULL if checks were not passed. + * + * It's possible on some configurations to have a setup like node0 node1 node0 + * i.e. it's possible that all pages within a zones range of pages do not + * belong to a single zone. We assume that a border between node0 and node1 + * can occur within a single pageblock, but not a node0 node1 node0 + * interleaving within a single pageblock. It is therefore sufficient to check + * the first and last page of a pageblock and avoid checking each individual + * page in a pageblock. + */ +struct page *__pageblock_pfn_to_page(unsigned long start_pfn, + unsigned long end_pfn, struct zone *zone) +{ + struct page *start_page; + struct page *end_page; + + /* end_pfn is one past the range we are checking */ + end_pfn--; + + if (!pfn_valid(start_pfn) || !pfn_valid(end_pfn)) + return NULL; + + start_page = pfn_to_online_page(start_pfn); + if (!start_page) + return NULL; + + if (page_zone(start_page) != zone) + return NULL; + + end_page = pfn_to_page(end_pfn); + + /* This gives a shorter code than deriving page_zone(end_page) */ + if (page_zone_id(start_page) != page_zone_id(end_page)) + return NULL; + + return start_page; +} + +void set_zone_contiguous(struct zone *zone) +{ + unsigned long block_start_pfn = zone->zone_start_pfn; + unsigned long block_end_pfn; + + block_end_pfn = ALIGN(block_start_pfn + 1, pageblock_nr_pages); + for (; block_start_pfn < zone_end_pfn(zone); + block_start_pfn = block_end_pfn, + block_end_pfn += pageblock_nr_pages) { + + block_end_pfn = min(block_end_pfn, zone_end_pfn(zone)); + + if (!__pageblock_pfn_to_page(block_start_pfn, + block_end_pfn, zone)) + return; + cond_resched(); + } + + /* We confirm that there is no hole */ + zone->contiguous = true; +} + +void clear_zone_contiguous(struct zone *zone) +{ + zone->contiguous = false; +} + +#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT +static void __init deferred_free_range(unsigned long pfn, + unsigned long nr_pages) +{ + struct page *page; + unsigned long i; + + if (!nr_pages) + return; + + page = pfn_to_page(pfn); + + /* Free a large naturally-aligned chunk if possible */ + if (nr_pages == pageblock_nr_pages && + (pfn & (pageblock_nr_pages - 1)) == 0) { + set_pageblock_migratetype(page, MIGRATE_MOVABLE); + __free_pages_boot_core(page, pageblock_order); + return; + } + + for (i = 0; i < nr_pages; i++, page++, pfn++) { + if ((pfn & (pageblock_nr_pages - 1)) == 0) + set_pageblock_migratetype(page, MIGRATE_MOVABLE); + __free_pages_boot_core(page, 0); + } +} + +/* Completion tracking for deferred_init_memmap() threads */ +static atomic_t pgdat_init_n_undone __initdata; +static __initdata DECLARE_COMPLETION(pgdat_init_all_done_comp); + +static inline void __init pgdat_init_report_one_done(void) +{ + if (atomic_dec_and_test(&pgdat_init_n_undone)) + complete(&pgdat_init_all_done_comp); +} + +/* + * Returns true if page needs to be initialized or freed to buddy allocator. + * + * First we check if pfn is valid on architectures where it is possible to have + * holes within pageblock_nr_pages. On systems where it is not possible, this + * function is optimized out. + * + * Then, we check if a current large page is valid by only checking the validity + * of the head pfn. + * + * Finally, meminit_pfn_in_nid is checked on systems where pfns can interleave + * within a node: a pfn is between start and end of a node, but does not belong + * to this memory node. + */ +static inline bool __init +deferred_pfn_valid(int nid, unsigned long pfn, + struct mminit_pfnnid_cache *nid_init_state) +{ + if (!pfn_valid_within(pfn)) + return false; + if (!(pfn & (pageblock_nr_pages - 1)) && !pfn_valid(pfn)) + return false; + if (!meminit_pfn_in_nid(pfn, nid, nid_init_state)) + return false; + return true; +} + +/* + * Free pages to buddy allocator. Try to free aligned pages in + * pageblock_nr_pages sizes. + */ +static void __init deferred_free_pages(int nid, int zid, unsigned long pfn, + unsigned long end_pfn) +{ + struct mminit_pfnnid_cache nid_init_state = { }; + unsigned long nr_pgmask = pageblock_nr_pages - 1; + unsigned long nr_free = 0; + + for (; pfn < end_pfn; pfn++) { + if (!deferred_pfn_valid(nid, pfn, &nid_init_state)) { + deferred_free_range(pfn - nr_free, nr_free); + nr_free = 0; + } else if (!(pfn & nr_pgmask)) { + deferred_free_range(pfn - nr_free, nr_free); + nr_free = 1; + touch_nmi_watchdog(); + } else { + nr_free++; + } + } + /* Free the last block of pages to allocator */ + deferred_free_range(pfn - nr_free, nr_free); +} + +/* + * Initialize struct pages. We minimize pfn page lookups and scheduler checks + * by performing it only once every pageblock_nr_pages. + * Return number of pages initialized. + */ +static unsigned long __init deferred_init_pages(int nid, int zid, + unsigned long pfn, + unsigned long end_pfn) +{ + struct mminit_pfnnid_cache nid_init_state = { }; + unsigned long nr_pgmask = pageblock_nr_pages - 1; + unsigned long nr_pages = 0; + struct page *page = NULL; + + for (; pfn < end_pfn; pfn++) { + if (!deferred_pfn_valid(nid, pfn, &nid_init_state)) { + page = NULL; + continue; + } else if (!page || !(pfn & nr_pgmask)) { + page = pfn_to_page(pfn); + touch_nmi_watchdog(); + } else { + page++; + } + __init_single_page(page, pfn, zid, nid); + nr_pages++; + } + return (nr_pages); +} + +/* Initialise remaining memory on a node */ +static int __init deferred_init_memmap(void *data) +{ + pg_data_t *pgdat = data; + int nid = pgdat->node_id; + unsigned long start = jiffies; + unsigned long nr_pages = 0; + unsigned long spfn, epfn, first_init_pfn, flags; + phys_addr_t spa, epa; + int zid; + struct zone *zone; + const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id); + u64 i; + + /* Bind memory initialisation thread to a local node if possible */ + if (!cpumask_empty(cpumask)) + set_cpus_allowed_ptr(current, cpumask); + + pgdat_resize_lock(pgdat, &flags); + first_init_pfn = pgdat->first_deferred_pfn; + if (first_init_pfn == ULONG_MAX) { + pgdat_resize_unlock(pgdat, &flags); + pgdat_init_report_one_done(); + return 0; + } + + /* Sanity check boundaries */ + BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn); + BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat)); + pgdat->first_deferred_pfn = ULONG_MAX; + + /* + * Once we unlock here, the zone cannot be grown anymore, thus if an + * interrupt thread must allocate this early in boot, zone must be + * pre-grown prior to start of deferred page initialization. + */ + pgdat_resize_unlock(pgdat, &flags); + + /* Only the highest zone is deferred so find it */ + for (zid = 0; zid < MAX_NR_ZONES; zid++) { + zone = pgdat->node_zones + zid; + if (first_init_pfn < zone_end_pfn(zone)) + break; + } + first_init_pfn = max(zone->zone_start_pfn, first_init_pfn); + + /* + * Initialize and free pages. We do it in two loops: first we initialize + * struct page, than free to buddy allocator, because while we are + * freeing pages we can access pages that are ahead (computing buddy + * page in __free_one_page()). + */ + for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &spa, &epa, NULL) { + spfn = max_t(unsigned long, first_init_pfn, PFN_UP(spa)); + epfn = min_t(unsigned long, zone_end_pfn(zone), PFN_DOWN(epa)); + nr_pages += deferred_init_pages(nid, zid, spfn, epfn); + } + for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &spa, &epa, NULL) { + spfn = max_t(unsigned long, first_init_pfn, PFN_UP(spa)); + epfn = min_t(unsigned long, zone_end_pfn(zone), PFN_DOWN(epa)); + deferred_free_pages(nid, zid, spfn, epfn); + } + + /* Sanity check that the next zone really is unpopulated */ + WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone)); + + pr_info("node %d initialised, %lu pages in %ums\n", nid, nr_pages, + jiffies_to_msecs(jiffies - start)); + + pgdat_init_report_one_done(); + return 0; +} + +/* + * If this zone has deferred pages, try to grow it by initializing enough + * deferred pages to satisfy the allocation specified by order, rounded up to + * the nearest PAGES_PER_SECTION boundary. So we're adding memory in increments + * of SECTION_SIZE bytes by initializing struct pages in increments of + * PAGES_PER_SECTION * sizeof(struct page) bytes. + * + * Return true when zone was grown, otherwise return false. We return true even + * when we grow less than requested, to let the caller decide if there are + * enough pages to satisfy the allocation. + * + * Note: We use noinline because this function is needed only during boot, and + * it is called from a __ref function _deferred_grow_zone. This way we are + * making sure that it is not inlined into permanent text section. + */ +static noinline bool __init +deferred_grow_zone(struct zone *zone, unsigned int order) +{ + int zid = zone_idx(zone); + int nid = zone_to_nid(zone); + pg_data_t *pgdat = NODE_DATA(nid); + unsigned long nr_pages_needed = ALIGN(1 << order, PAGES_PER_SECTION); + unsigned long nr_pages = 0; + unsigned long first_init_pfn, spfn, epfn, t, flags; + unsigned long first_deferred_pfn = pgdat->first_deferred_pfn; + phys_addr_t spa, epa; + u64 i; + + /* Only the last zone may have deferred pages */ + if (zone_end_pfn(zone) != pgdat_end_pfn(pgdat)) + return false; + + pgdat_resize_lock(pgdat, &flags); + + /* + * If someone grew this zone while we were waiting for spinlock, return + * true, as there might be enough pages already. + */ + if (first_deferred_pfn != pgdat->first_deferred_pfn) { + pgdat_resize_unlock(pgdat, &flags); + return true; + } + + first_init_pfn = max(zone->zone_start_pfn, first_deferred_pfn); + + if (first_init_pfn >= pgdat_end_pfn(pgdat)) { + pgdat_resize_unlock(pgdat, &flags); + return false; + } + + for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &spa, &epa, NULL) { + spfn = max_t(unsigned long, first_init_pfn, PFN_UP(spa)); + epfn = min_t(unsigned long, zone_end_pfn(zone), PFN_DOWN(epa)); + + while (spfn < epfn && nr_pages < nr_pages_needed) { + t = ALIGN(spfn + PAGES_PER_SECTION, PAGES_PER_SECTION); + first_deferred_pfn = min(t, epfn); + nr_pages += deferred_init_pages(nid, zid, spfn, + first_deferred_pfn); + spfn = first_deferred_pfn; + } + + if (nr_pages >= nr_pages_needed) + break; + } + + for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &spa, &epa, NULL) { + spfn = max_t(unsigned long, first_init_pfn, PFN_UP(spa)); + epfn = min_t(unsigned long, first_deferred_pfn, PFN_DOWN(epa)); + deferred_free_pages(nid, zid, spfn, epfn); + + if (first_deferred_pfn == epfn) + break; + } + pgdat->first_deferred_pfn = first_deferred_pfn; + pgdat_resize_unlock(pgdat, &flags); + + return nr_pages > 0; +} + +/* + * deferred_grow_zone() is __init, but it is called from + * get_page_from_freelist() during early boot until deferred_pages permanently + * disables this call. This is why we have refdata wrapper to avoid warning, + * and to ensure that the function body gets unloaded. + */ +static bool __ref +_deferred_grow_zone(struct zone *zone, unsigned int order) +{ + return deferred_grow_zone(zone, order); +} + +#endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ + +void __init page_alloc_init_late(void) +{ + struct zone *zone; + +#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT + int nid; + + /* There will be num_node_state(N_MEMORY) threads */ + atomic_set(&pgdat_init_n_undone, num_node_state(N_MEMORY)); + for_each_node_state(nid, N_MEMORY) { + kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid); + } + + /* Block until all are initialised */ + wait_for_completion(&pgdat_init_all_done_comp); + + /* + * The number of managed pages has changed due to the initialisation + * so the pcpu batch and high limits needs to be updated or the limits + * will be artificially small. + */ + for_each_populated_zone(zone) + zone_pcp_update(zone); + + /* + * We initialized the rest of the deferred pages. Permanently disable + * on-demand struct page initialization. + */ + static_branch_disable(&deferred_pages); + + /* Reinit limits that are based on free pages after the kernel is up */ + files_maxfiles_init(); +#endif +#ifdef CONFIG_ARCH_DISCARD_MEMBLOCK + /* Discard memblock private memory */ + memblock_discard(); +#endif + + for_each_populated_zone(zone) + set_zone_contiguous(zone); +} + +#ifdef CONFIG_CMA +/* Free whole pageblock and set its migration type to MIGRATE_CMA. */ +void __init init_cma_reserved_pageblock(struct page *page) +{ + unsigned i = pageblock_nr_pages; + struct page *p = page; + + do { + __ClearPageReserved(p); + set_page_count(p, 0); + } while (++p, --i); + + set_pageblock_migratetype(page, MIGRATE_CMA); + + if (pageblock_order >= MAX_ORDER) { + i = pageblock_nr_pages; + p = page; + do { + set_page_refcounted(p); + __free_pages(p, MAX_ORDER - 1); + p += MAX_ORDER_NR_PAGES; + } while (i -= MAX_ORDER_NR_PAGES); + } else { + set_page_refcounted(page); + __free_pages(page, pageblock_order); + } + + adjust_managed_page_count(page, pageblock_nr_pages); +} +#endif + +/* + * The order of subdivision here is critical for the IO subsystem. + * Please do not alter this order without good reasons and regression + * testing. Specifically, as large blocks of memory are subdivided, + * the order in which smaller blocks are delivered depends on the order + * they're subdivided in this function. This is the primary factor + * influencing the order in which pages are delivered to the IO + * subsystem according to empirical testing, and this is also justified + * by considering the behavior of a buddy system containing a single + * large block of memory acted on by a series of small allocations. + * This behavior is a critical factor in sglist merging's success. + * + * -- nyc + */ +static inline void expand(struct zone *zone, struct page *page, + int low, int high, struct free_area *area, + int migratetype) +{ + unsigned long size = 1 << high; + + while (high > low) { + area--; + high--; + size >>= 1; + VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]); + + /* + * Mark as guard pages (or page), that will allow to + * merge back to allocator when buddy will be freed. + * Corresponding page table entries will not be touched, + * pages will stay not present in virtual address space + */ + if (set_page_guard(zone, &page[size], high, migratetype)) + continue; + + list_add(&page[size].lru, &area->free_list[migratetype]); + area->nr_free++; + set_page_order(&page[size], high); + } +} + +static void check_new_page_bad(struct page *page) +{ + const char *bad_reason = NULL; + unsigned long bad_flags = 0; + + if (unlikely(atomic_read(&page->_mapcount) != -1)) + bad_reason = "nonzero mapcount"; + if (unlikely(page->mapping != NULL)) + bad_reason = "non-NULL mapping"; + if (unlikely(page_ref_count(page) != 0)) + bad_reason = "nonzero _count"; + if (unlikely(page->flags & __PG_HWPOISON)) { + bad_reason = "HWPoisoned (hardware-corrupted)"; + bad_flags = __PG_HWPOISON; + /* Don't complain about hwpoisoned pages */ + page_mapcount_reset(page); /* remove PageBuddy */ + return; + } + if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) { + bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set"; + bad_flags = PAGE_FLAGS_CHECK_AT_PREP; + } +#ifdef CONFIG_MEMCG + if (unlikely(page->mem_cgroup)) + bad_reason = "page still charged to cgroup"; +#endif + bad_page(page, bad_reason, bad_flags); +} + +/* + * This page is about to be returned from the page allocator + */ +static inline int check_new_page(struct page *page) +{ + if (likely(page_expected_state(page, + PAGE_FLAGS_CHECK_AT_PREP|__PG_HWPOISON))) + return 0; + + check_new_page_bad(page); + return 1; +} + +static inline bool free_pages_prezeroed(void) +{ + return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) && + page_poisoning_enabled(); +} + +#ifdef CONFIG_DEBUG_VM +static bool check_pcp_refill(struct page *page) +{ + return false; +} + +static bool check_new_pcp(struct page *page) +{ + return check_new_page(page); +} +#else +static bool check_pcp_refill(struct page *page) +{ + return check_new_page(page); +} +static bool check_new_pcp(struct page *page) +{ + return false; +} +#endif /* CONFIG_DEBUG_VM */ + +static bool check_new_pages(struct page *page, unsigned int order) +{ + int i; + for (i = 0; i < (1 << order); i++) { + struct page *p = page + i; + + if (unlikely(check_new_page(p))) + return true; + } + + return false; +} + +inline void post_alloc_hook(struct page *page, unsigned int order, + gfp_t gfp_flags) +{ + set_page_private(page, 0); + set_page_refcounted(page); + + arch_alloc_page(page, order); + kernel_map_pages(page, 1 << order, 1); + kasan_alloc_pages(page, order); + kernel_poison_pages(page, 1 << order, 1); + set_page_owner(page, order, gfp_flags); +} + +static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags, + unsigned int alloc_flags) +{ + int i; + + post_alloc_hook(page, order, gfp_flags); + + if (!free_pages_prezeroed() && (gfp_flags & __GFP_ZERO)) + for (i = 0; i < (1 << order); i++) + clear_highpage(page + i); + + if (order && (gfp_flags & __GFP_COMP)) + prep_compound_page(page, order); + + /* + * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to + * allocate the page. The expectation is that the caller is taking + * steps that will free more memory. The caller should avoid the page + * being used for !PFMEMALLOC purposes. + */ + if (alloc_flags & ALLOC_NO_WATERMARKS) + set_page_pfmemalloc(page); + else + clear_page_pfmemalloc(page); +} + +/* + * Go through the free lists for the given migratetype and remove + * the smallest available page from the freelists + */ +static __always_inline +struct page *__rmqueue_smallest(struct zone *zone, unsigned int order, + int migratetype) +{ + unsigned int current_order; + struct free_area *area; + struct page *page; + + /* Find a page of the appropriate size in the preferred list */ + for (current_order = order; current_order < MAX_ORDER; ++current_order) { + area = &(zone->free_area[current_order]); + page = list_first_entry_or_null(&area->free_list[migratetype], + struct page, lru); + if (!page) + continue; + list_del(&page->lru); + rmv_page_order(page); + area->nr_free--; + expand(zone, page, order, current_order, area, migratetype); + set_pcppage_migratetype(page, migratetype); + return page; + } + + return NULL; +} + + +/* + * This array describes the order lists are fallen back to when + * the free lists for the desirable migrate type are depleted + */ +static int fallbacks[MIGRATE_TYPES][4] = { + [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES }, + [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES }, + [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES }, +#ifdef CONFIG_CMA + [MIGRATE_CMA] = { MIGRATE_TYPES }, /* Never used */ +#endif +#ifdef CONFIG_MEMORY_ISOLATION + [MIGRATE_ISOLATE] = { MIGRATE_TYPES }, /* Never used */ +#endif +}; + +#ifdef CONFIG_CMA +static __always_inline struct page *__rmqueue_cma_fallback(struct zone *zone, + unsigned int order) +{ + return __rmqueue_smallest(zone, order, MIGRATE_CMA); +} +#else +static inline struct page *__rmqueue_cma_fallback(struct zone *zone, + unsigned int order) { return NULL; } +#endif + +/* + * Move the free pages in a range to the free lists of the requested type. + * Note that start_page and end_pages are not aligned on a pageblock + * boundary. If alignment is required, use move_freepages_block() + */ +static int move_freepages(struct zone *zone, + struct page *start_page, struct page *end_page, + int migratetype, int *num_movable) +{ + struct page *page; + unsigned int order; + int pages_moved = 0; + +#ifndef CONFIG_HOLES_IN_ZONE + /* + * page_zone is not safe to call in this context when + * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant + * anyway as we check zone boundaries in move_freepages_block(). + * Remove at a later date when no bug reports exist related to + * grouping pages by mobility + */ + VM_BUG_ON(pfn_valid(page_to_pfn(start_page)) && + pfn_valid(page_to_pfn(end_page)) && + page_zone(start_page) != page_zone(end_page)); +#endif + + if (num_movable) + *num_movable = 0; + + for (page = start_page; page <= end_page;) { + if (!pfn_valid_within(page_to_pfn(page))) { + page++; + continue; + } + + /* Make sure we are not inadvertently changing nodes */ + VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page); + + if (!PageBuddy(page)) { + /* + * We assume that pages that could be isolated for + * migration are movable. But we don't actually try + * isolating, as that would be expensive. + */ + if (num_movable && + (PageLRU(page) || __PageMovable(page))) + (*num_movable)++; + + page++; + continue; + } + + order = page_order(page); + list_move(&page->lru, + &zone->free_area[order].free_list[migratetype]); + page += 1 << order; + pages_moved += 1 << order; + } + + return pages_moved; +} + +int move_freepages_block(struct zone *zone, struct page *page, + int migratetype, int *num_movable) +{ + unsigned long start_pfn, end_pfn; + struct page *start_page, *end_page; + + start_pfn = page_to_pfn(page); + start_pfn = start_pfn & ~(pageblock_nr_pages-1); + start_page = pfn_to_page(start_pfn); + end_page = start_page + pageblock_nr_pages - 1; + end_pfn = start_pfn + pageblock_nr_pages - 1; + + /* Do not cross zone boundaries */ + if (!zone_spans_pfn(zone, start_pfn)) + start_page = page; + if (!zone_spans_pfn(zone, end_pfn)) + return 0; + + return move_freepages(zone, start_page, end_page, migratetype, + num_movable); +} + +static void change_pageblock_range(struct page *pageblock_page, + int start_order, int migratetype) +{ + int nr_pageblocks = 1 << (start_order - pageblock_order); + + while (nr_pageblocks--) { + set_pageblock_migratetype(pageblock_page, migratetype); + pageblock_page += pageblock_nr_pages; + } +} + +/* + * When we are falling back to another migratetype during allocation, try to + * steal extra free pages from the same pageblocks to satisfy further + * allocations, instead of polluting multiple pageblocks. + * + * If we are stealing a relatively large buddy page, it is likely there will + * be more free pages in the pageblock, so try to steal them all. For + * reclaimable and unmovable allocations, we steal regardless of page size, + * as fragmentation caused by those allocations polluting movable pageblocks + * is worse than movable allocations stealing from unmovable and reclaimable + * pageblocks. + */ +static bool can_steal_fallback(unsigned int order, int start_mt) +{ + /* + * Leaving this order check is intended, although there is + * relaxed order check in next check. The reason is that + * we can actually steal whole pageblock if this condition met, + * but, below check doesn't guarantee it and that is just heuristic + * so could be changed anytime. + */ + if (order >= pageblock_order) + return true; + + if (order >= pageblock_order / 2 || + start_mt == MIGRATE_RECLAIMABLE || + start_mt == MIGRATE_UNMOVABLE || + page_group_by_mobility_disabled) + return true; + + return false; +} + +/* + * This function implements actual steal behaviour. If order is large enough, + * we can steal whole pageblock. If not, we first move freepages in this + * pageblock to our migratetype and determine how many already-allocated pages + * are there in the pageblock with a compatible migratetype. If at least half + * of pages are free or compatible, we can change migratetype of the pageblock + * itself, so pages freed in the future will be put on the correct free list. + */ +static void steal_suitable_fallback(struct zone *zone, struct page *page, + int start_type, bool whole_block) +{ + unsigned int current_order = page_order(page); + struct free_area *area; + int free_pages, movable_pages, alike_pages; + int old_block_type; + + old_block_type = get_pageblock_migratetype(page); + + /* + * This can happen due to races and we want to prevent broken + * highatomic accounting. + */ + if (is_migrate_highatomic(old_block_type)) + goto single_page; + + /* Take ownership for orders >= pageblock_order */ + if (current_order >= pageblock_order) { + change_pageblock_range(page, current_order, start_type); + goto single_page; + } + + /* We are not allowed to try stealing from the whole block */ + if (!whole_block) + goto single_page; + + free_pages = move_freepages_block(zone, page, start_type, + &movable_pages); + /* + * Determine how many pages are compatible with our allocation. + * For movable allocation, it's the number of movable pages which + * we just obtained. For other types it's a bit more tricky. + */ + if (start_type == MIGRATE_MOVABLE) { + alike_pages = movable_pages; + } else { + /* + * If we are falling back a RECLAIMABLE or UNMOVABLE allocation + * to MOVABLE pageblock, consider all non-movable pages as + * compatible. If it's UNMOVABLE falling back to RECLAIMABLE or + * vice versa, be conservative since we can't distinguish the + * exact migratetype of non-movable pages. + */ + if (old_block_type == MIGRATE_MOVABLE) + alike_pages = pageblock_nr_pages + - (free_pages + movable_pages); + else + alike_pages = 0; + } + + /* moving whole block can fail due to zone boundary conditions */ + if (!free_pages) + goto single_page; + + /* + * If a sufficient number of pages in the block are either free or of + * comparable migratability as our allocation, claim the whole block. + */ + if (free_pages + alike_pages >= (1 << (pageblock_order-1)) || + page_group_by_mobility_disabled) + set_pageblock_migratetype(page, start_type); + + return; + +single_page: + area = &zone->free_area[current_order]; + list_move(&page->lru, &area->free_list[start_type]); +} + +/* + * Check whether there is a suitable fallback freepage with requested order. + * If only_stealable is true, this function returns fallback_mt only if + * we can steal other freepages all together. This would help to reduce + * fragmentation due to mixed migratetype pages in one pageblock. + */ +int find_suitable_fallback(struct free_area *area, unsigned int order, + int migratetype, bool only_stealable, bool *can_steal) +{ + int i; + int fallback_mt; + + if (area->nr_free == 0) + return -1; + + *can_steal = false; + for (i = 0;; i++) { + fallback_mt = fallbacks[migratetype][i]; + if (fallback_mt == MIGRATE_TYPES) + break; + + if (list_empty(&area->free_list[fallback_mt])) + continue; + + if (can_steal_fallback(order, migratetype)) + *can_steal = true; + + if (!only_stealable) + return fallback_mt; + + if (*can_steal) + return fallback_mt; + } + + return -1; +} + +/* + * Reserve a pageblock for exclusive use of high-order atomic allocations if + * there are no empty page blocks that contain a page with a suitable order + */ +static void reserve_highatomic_pageblock(struct page *page, struct zone *zone, + unsigned int alloc_order) +{ + int mt; + unsigned long max_managed, flags; + + /* + * Limit the number reserved to 1 pageblock or roughly 1% of a zone. + * Check is race-prone but harmless. + */ + max_managed = (zone->managed_pages / 100) + pageblock_nr_pages; + if (zone->nr_reserved_highatomic >= max_managed) + return; + + spin_lock_irqsave(&zone->lock, flags); + + /* Recheck the nr_reserved_highatomic limit under the lock */ + if (zone->nr_reserved_highatomic >= max_managed) + goto out_unlock; + + /* Yoink! */ + mt = get_pageblock_migratetype(page); + if (!is_migrate_highatomic(mt) && !is_migrate_isolate(mt) + && !is_migrate_cma(mt)) { + zone->nr_reserved_highatomic += pageblock_nr_pages; + set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC); + move_freepages_block(zone, page, MIGRATE_HIGHATOMIC, NULL); + } + +out_unlock: + spin_unlock_irqrestore(&zone->lock, flags); +} + +/* + * Used when an allocation is about to fail under memory pressure. This + * potentially hurts the reliability of high-order allocations when under + * intense memory pressure but failed atomic allocations should be easier + * to recover from than an OOM. + * + * If @force is true, try to unreserve a pageblock even though highatomic + * pageblock is exhausted. + */ +static bool unreserve_highatomic_pageblock(const struct alloc_context *ac, + bool force) +{ + struct zonelist *zonelist = ac->zonelist; + unsigned long flags; + struct zoneref *z; + struct zone *zone; + struct page *page; + int order; + bool ret; + + for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx, + ac->nodemask) { + /* + * Preserve at least one pageblock unless memory pressure + * is really high. + */ + if (!force && zone->nr_reserved_highatomic <= + pageblock_nr_pages) + continue; + + spin_lock_irqsave(&zone->lock, flags); + for (order = 0; order < MAX_ORDER; order++) { + struct free_area *area = &(zone->free_area[order]); + + page = list_first_entry_or_null( + &area->free_list[MIGRATE_HIGHATOMIC], + struct page, lru); + if (!page) + continue; + + /* + * In page freeing path, migratetype change is racy so + * we can counter several free pages in a pageblock + * in this loop althoug we changed the pageblock type + * from highatomic to ac->migratetype. So we should + * adjust the count once. + */ + if (is_migrate_highatomic_page(page)) { + /* + * It should never happen but changes to + * locking could inadvertently allow a per-cpu + * drain to add pages to MIGRATE_HIGHATOMIC + * while unreserving so be safe and watch for + * underflows. + */ + zone->nr_reserved_highatomic -= min( + pageblock_nr_pages, + zone->nr_reserved_highatomic); + } + + /* + * Convert to ac->migratetype and avoid the normal + * pageblock stealing heuristics. Minimally, the caller + * is doing the work and needs the pages. More + * importantly, if the block was always converted to + * MIGRATE_UNMOVABLE or another type then the number + * of pageblocks that cannot be completely freed + * may increase. + */ + set_pageblock_migratetype(page, ac->migratetype); + ret = move_freepages_block(zone, page, ac->migratetype, + NULL); + if (ret) { + spin_unlock_irqrestore(&zone->lock, flags); + return ret; + } + } + spin_unlock_irqrestore(&zone->lock, flags); + } + + return false; +} + +/* + * Try finding a free buddy page on the fallback list and put it on the free + * list of requested migratetype, possibly along with other pages from the same + * block, depending on fragmentation avoidance heuristics. Returns true if + * fallback was found so that __rmqueue_smallest() can grab it. + * + * The use of signed ints for order and current_order is a deliberate + * deviation from the rest of this file, to make the for loop + * condition simpler. + */ +static __always_inline bool +__rmqueue_fallback(struct zone *zone, int order, int start_migratetype) +{ + struct free_area *area; + int current_order; + struct page *page; + int fallback_mt; + bool can_steal; + + /* + * Find the largest available free page in the other list. This roughly + * approximates finding the pageblock with the most free pages, which + * would be too costly to do exactly. + */ + for (current_order = MAX_ORDER - 1; current_order >= order; + --current_order) { + area = &(zone->free_area[current_order]); + fallback_mt = find_suitable_fallback(area, current_order, + start_migratetype, false, &can_steal); + if (fallback_mt == -1) + continue; + + /* + * We cannot steal all free pages from the pageblock and the + * requested migratetype is movable. In that case it's better to + * steal and split the smallest available page instead of the + * largest available page, because even if the next movable + * allocation falls back into a different pageblock than this + * one, it won't cause permanent fragmentation. + */ + if (!can_steal && start_migratetype == MIGRATE_MOVABLE + && current_order > order) + goto find_smallest; + + goto do_steal; + } + + return false; + +find_smallest: + for (current_order = order; current_order < MAX_ORDER; + current_order++) { + area = &(zone->free_area[current_order]); + fallback_mt = find_suitable_fallback(area, current_order, + start_migratetype, false, &can_steal); + if (fallback_mt != -1) + break; + } + + /* + * This should not happen - we already found a suitable fallback + * when looking for the largest page. + */ + VM_BUG_ON(current_order == MAX_ORDER); + +do_steal: + page = list_first_entry(&area->free_list[fallback_mt], + struct page, lru); + + steal_suitable_fallback(zone, page, start_migratetype, can_steal); + + trace_mm_page_alloc_extfrag(page, order, current_order, + start_migratetype, fallback_mt); + + return true; + +} + +/* + * Do the hard work of removing an element from the buddy allocator. + * Call me with the zone->lock already held. + */ +static __always_inline struct page * +__rmqueue(struct zone *zone, unsigned int order, int migratetype) +{ + struct page *page; + +retry: + page = __rmqueue_smallest(zone, order, migratetype); + if (unlikely(!page)) { + if (migratetype == MIGRATE_MOVABLE) + page = __rmqueue_cma_fallback(zone, order); + + if (!page && __rmqueue_fallback(zone, order, migratetype)) + goto retry; + } + + trace_mm_page_alloc_zone_locked(page, order, migratetype); + return page; +} + +/* + * Obtain a specified number of elements from the buddy allocator, all under + * a single hold of the lock, for efficiency. Add them to the supplied list. + * Returns the number of new pages which were placed at *list. + */ +static int rmqueue_bulk(struct zone *zone, unsigned int order, + unsigned long count, struct list_head *list, + int migratetype) +{ + int i, alloced = 0; + + spin_lock(&zone->lock); + for (i = 0; i < count; ++i) { + struct page *page = __rmqueue(zone, order, migratetype); + if (unlikely(page == NULL)) + break; + + if (unlikely(check_pcp_refill(page))) + continue; + + /* + * Split buddy pages returned by expand() are received here in + * physical page order. The page is added to the tail of + * caller's list. From the callers perspective, the linked list + * is ordered by page number under some conditions. This is + * useful for IO devices that can forward direction from the + * head, thus also in the physical page order. This is useful + * for IO devices that can merge IO requests if the physical + * pages are ordered properly. + */ + list_add_tail(&page->lru, list); + alloced++; + if (is_migrate_cma(get_pcppage_migratetype(page))) + __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, + -(1 << order)); + } + + /* + * i pages were removed from the buddy list even if some leak due + * to check_pcp_refill failing so adjust NR_FREE_PAGES based + * on i. Do not confuse with 'alloced' which is the number of + * pages added to the pcp list. + */ + __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order)); + spin_unlock(&zone->lock); + return alloced; +} + +#ifdef CONFIG_NUMA +/* + * Called from the vmstat counter updater to drain pagesets of this + * currently executing processor on remote nodes after they have + * expired. + * + * Note that this function must be called with the thread pinned to + * a single processor. + */ +void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp) +{ + unsigned long flags; + int to_drain, batch; + + local_irq_save(flags); + batch = READ_ONCE(pcp->batch); + to_drain = min(pcp->count, batch); + if (to_drain > 0) + free_pcppages_bulk(zone, to_drain, pcp); + local_irq_restore(flags); +} +#endif + +/* + * Drain pcplists of the indicated processor and zone. + * + * The processor must either be the current processor and the + * thread pinned to the current processor or a processor that + * is not online. + */ +static void drain_pages_zone(unsigned int cpu, struct zone *zone) +{ + unsigned long flags; + struct per_cpu_pageset *pset; + struct per_cpu_pages *pcp; + + local_irq_save(flags); + pset = per_cpu_ptr(zone->pageset, cpu); + + pcp = &pset->pcp; + if (pcp->count) + free_pcppages_bulk(zone, pcp->count, pcp); + local_irq_restore(flags); +} + +/* + * Drain pcplists of all zones on the indicated processor. + * + * The processor must either be the current processor and the + * thread pinned to the current processor or a processor that + * is not online. + */ +static void drain_pages(unsigned int cpu) +{ + struct zone *zone; + + for_each_populated_zone(zone) { + drain_pages_zone(cpu, zone); + } +} + +/* + * Spill all of this CPU's per-cpu pages back into the buddy allocator. + * + * The CPU has to be pinned. When zone parameter is non-NULL, spill just + * the single zone's pages. + */ +void drain_local_pages(struct zone *zone) +{ + int cpu = smp_processor_id(); + + if (zone) + drain_pages_zone(cpu, zone); + else + drain_pages(cpu); +} + +static void drain_local_pages_wq(struct work_struct *work) +{ + /* + * drain_all_pages doesn't use proper cpu hotplug protection so + * we can race with cpu offline when the WQ can move this from + * a cpu pinned worker to an unbound one. We can operate on a different + * cpu which is allright but we also have to make sure to not move to + * a different one. + */ + preempt_disable(); + drain_local_pages(NULL); + preempt_enable(); +} + +/* + * Spill all the per-cpu pages from all CPUs back into the buddy allocator. + * + * When zone parameter is non-NULL, spill just the single zone's pages. + * + * Note that this can be extremely slow as the draining happens in a workqueue. + */ +void drain_all_pages(struct zone *zone) +{ + int cpu; + + /* + * Allocate in the BSS so we wont require allocation in + * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y + */ + static cpumask_t cpus_with_pcps; + + /* + * Make sure nobody triggers this path before mm_percpu_wq is fully + * initialized. + */ + if (WARN_ON_ONCE(!mm_percpu_wq)) + return; + + /* + * Do not drain if one is already in progress unless it's specific to + * a zone. Such callers are primarily CMA and memory hotplug and need + * the drain to be complete when the call returns. + */ + if (unlikely(!mutex_trylock(&pcpu_drain_mutex))) { + if (!zone) + return; + mutex_lock(&pcpu_drain_mutex); + } + + /* + * We don't care about racing with CPU hotplug event + * as offline notification will cause the notified + * cpu to drain that CPU pcps and on_each_cpu_mask + * disables preemption as part of its processing + */ + for_each_online_cpu(cpu) { + struct per_cpu_pageset *pcp; + struct zone *z; + bool has_pcps = false; + + if (zone) { + pcp = per_cpu_ptr(zone->pageset, cpu); + if (pcp->pcp.count) + has_pcps = true; + } else { + for_each_populated_zone(z) { + pcp = per_cpu_ptr(z->pageset, cpu); + if (pcp->pcp.count) { + has_pcps = true; + break; + } + } + } + + if (has_pcps) + cpumask_set_cpu(cpu, &cpus_with_pcps); + else + cpumask_clear_cpu(cpu, &cpus_with_pcps); + } + + for_each_cpu(cpu, &cpus_with_pcps) { + struct work_struct *work = per_cpu_ptr(&pcpu_drain, cpu); + INIT_WORK(work, drain_local_pages_wq); + queue_work_on(cpu, mm_percpu_wq, work); + } + for_each_cpu(cpu, &cpus_with_pcps) + flush_work(per_cpu_ptr(&pcpu_drain, cpu)); + + mutex_unlock(&pcpu_drain_mutex); +} + +#ifdef CONFIG_HIBERNATION + +/* + * Touch the watchdog for every WD_PAGE_COUNT pages. + */ +#define WD_PAGE_COUNT (128*1024) + +void mark_free_pages(struct zone *zone) +{ + unsigned long pfn, max_zone_pfn, page_count = WD_PAGE_COUNT; + unsigned long flags; + unsigned int order, t; + struct page *page; + + if (zone_is_empty(zone)) + return; + + spin_lock_irqsave(&zone->lock, flags); + + max_zone_pfn = zone_end_pfn(zone); + for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) + if (pfn_valid(pfn)) { + page = pfn_to_page(pfn); + + if (!--page_count) { + touch_nmi_watchdog(); + page_count = WD_PAGE_COUNT; + } + + if (page_zone(page) != zone) + continue; + + if (!swsusp_page_is_forbidden(page)) + swsusp_unset_page_free(page); + } + + for_each_migratetype_order(order, t) { + list_for_each_entry(page, + &zone->free_area[order].free_list[t], lru) { + unsigned long i; + + pfn = page_to_pfn(page); + for (i = 0; i < (1UL << order); i++) { + if (!--page_count) { + touch_nmi_watchdog(); + page_count = WD_PAGE_COUNT; + } + swsusp_set_page_free(pfn_to_page(pfn + i)); + } + } + } + spin_unlock_irqrestore(&zone->lock, flags); +} +#endif /* CONFIG_PM */ + +static bool free_unref_page_prepare(struct page *page, unsigned long pfn) +{ + int migratetype; + + if (!free_pcp_prepare(page)) + return false; + + migratetype = get_pfnblock_migratetype(page, pfn); + set_pcppage_migratetype(page, migratetype); + return true; +} + +static void free_unref_page_commit(struct page *page, unsigned long pfn) +{ + struct zone *zone = page_zone(page); + struct per_cpu_pages *pcp; + int migratetype; + + migratetype = get_pcppage_migratetype(page); + __count_vm_event(PGFREE); + + /* + * We only track unmovable, reclaimable and movable on pcp lists. + * Free ISOLATE pages back to the allocator because they are being + * offlined but treat HIGHATOMIC as movable pages so we can get those + * areas back if necessary. Otherwise, we may have to free + * excessively into the page allocator + */ + if (migratetype >= MIGRATE_PCPTYPES) { + if (unlikely(is_migrate_isolate(migratetype))) { + free_one_page(zone, page, pfn, 0, migratetype); + return; + } + migratetype = MIGRATE_MOVABLE; + } + + pcp = &this_cpu_ptr(zone->pageset)->pcp; + list_add(&page->lru, &pcp->lists[migratetype]); + pcp->count++; + if (pcp->count >= pcp->high) { + unsigned long batch = READ_ONCE(pcp->batch); + free_pcppages_bulk(zone, batch, pcp); + } +} + +/* + * Free a 0-order page + */ +void free_unref_page(struct page *page) +{ + unsigned long flags; + unsigned long pfn = page_to_pfn(page); + + if (!free_unref_page_prepare(page, pfn)) + return; + + local_irq_save(flags); + free_unref_page_commit(page, pfn); + local_irq_restore(flags); +} + +/* + * Free a list of 0-order pages + */ +void free_unref_page_list(struct list_head *list) +{ + struct page *page, *next; + unsigned long flags, pfn; + int batch_count = 0; + + /* Prepare pages for freeing */ + list_for_each_entry_safe(page, next, list, lru) { + pfn = page_to_pfn(page); + if (!free_unref_page_prepare(page, pfn)) + list_del(&page->lru); + set_page_private(page, pfn); + } + + local_irq_save(flags); + list_for_each_entry_safe(page, next, list, lru) { + unsigned long pfn = page_private(page); + + set_page_private(page, 0); + trace_mm_page_free_batched(page); + free_unref_page_commit(page, pfn); + + /* + * Guard against excessive IRQ disabled times when we get + * a large list of pages to free. + */ + if (++batch_count == SWAP_CLUSTER_MAX) { + local_irq_restore(flags); + batch_count = 0; + local_irq_save(flags); + } + } + local_irq_restore(flags); +} + +/* + * split_page takes a non-compound higher-order page, and splits it into + * n (1<<order) sub-pages: page[0..n] + * Each sub-page must be freed individually. + * + * Note: this is probably too low level an operation for use in drivers. + * Please consult with lkml before using this in your driver. + */ +void split_page(struct page *page, unsigned int order) +{ + int i; + + VM_BUG_ON_PAGE(PageCompound(page), page); + VM_BUG_ON_PAGE(!page_count(page), page); + + for (i = 1; i < (1 << order); i++) + set_page_refcounted(page + i); + split_page_owner(page, order); +} +EXPORT_SYMBOL_GPL(split_page); + +int __isolate_free_page(struct page *page, unsigned int order) +{ + unsigned long watermark; + struct zone *zone; + int mt; + + BUG_ON(!PageBuddy(page)); + + zone = page_zone(page); + mt = get_pageblock_migratetype(page); + + if (!is_migrate_isolate(mt)) { + /* + * Obey watermarks as if the page was being allocated. We can + * emulate a high-order watermark check with a raised order-0 + * watermark, because we already know our high-order page + * exists. + */ + watermark = min_wmark_pages(zone) + (1UL << order); + if (!zone_watermark_ok(zone, 0, watermark, 0, ALLOC_CMA)) + return 0; + + __mod_zone_freepage_state(zone, -(1UL << order), mt); + } + + /* Remove page from free list */ + list_del(&page->lru); + zone->free_area[order].nr_free--; + rmv_page_order(page); + + /* + * Set the pageblock if the isolated page is at least half of a + * pageblock + */ + if (order >= pageblock_order - 1) { + struct page *endpage = page + (1 << order) - 1; + for (; page < endpage; page += pageblock_nr_pages) { + int mt = get_pageblock_migratetype(page); + if (!is_migrate_isolate(mt) && !is_migrate_cma(mt) + && !is_migrate_highatomic(mt)) + set_pageblock_migratetype(page, + MIGRATE_MOVABLE); + } + } + + + return 1UL << order; +} + +/* + * Update NUMA hit/miss statistics + * + * Must be called with interrupts disabled. + */ +static inline void zone_statistics(struct zone *preferred_zone, struct zone *z) +{ +#ifdef CONFIG_NUMA + enum numa_stat_item local_stat = NUMA_LOCAL; + + /* skip numa counters update if numa stats is disabled */ + if (!static_branch_likely(&vm_numa_stat_key)) + return; + + if (zone_to_nid(z) != numa_node_id()) + local_stat = NUMA_OTHER; + + if (zone_to_nid(z) == zone_to_nid(preferred_zone)) + __inc_numa_state(z, NUMA_HIT); + else { + __inc_numa_state(z, NUMA_MISS); + __inc_numa_state(preferred_zone, NUMA_FOREIGN); + } + __inc_numa_state(z, local_stat); +#endif +} + +/* Remove page from the per-cpu list, caller must protect the list */ +static struct page *__rmqueue_pcplist(struct zone *zone, int migratetype, + struct per_cpu_pages *pcp, + struct list_head *list) +{ + struct page *page; + + do { + if (list_empty(list)) { + pcp->count += rmqueue_bulk(zone, 0, + pcp->batch, list, + migratetype); + if (unlikely(list_empty(list))) + return NULL; + } + + page = list_first_entry(list, struct page, lru); + list_del(&page->lru); + pcp->count--; + } while (check_new_pcp(page)); + + return page; +} + +/* Lock and remove page from the per-cpu list */ +static struct page *rmqueue_pcplist(struct zone *preferred_zone, + struct zone *zone, unsigned int order, + gfp_t gfp_flags, int migratetype) +{ + struct per_cpu_pages *pcp; + struct list_head *list; + struct page *page; + unsigned long flags; + + local_irq_save(flags); + pcp = &this_cpu_ptr(zone->pageset)->pcp; + list = &pcp->lists[migratetype]; + page = __rmqueue_pcplist(zone, migratetype, pcp, list); + if (page) { + __count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order); + zone_statistics(preferred_zone, zone); + } + local_irq_restore(flags); + return page; +} + +/* + * Allocate a page from the given zone. Use pcplists for order-0 allocations. + */ +static inline +struct page *rmqueue(struct zone *preferred_zone, + struct zone *zone, unsigned int order, + gfp_t gfp_flags, unsigned int alloc_flags, + int migratetype) +{ + unsigned long flags; + struct page *page; + + if (likely(order == 0)) { + page = rmqueue_pcplist(preferred_zone, zone, order, + gfp_flags, migratetype); + goto out; + } + + /* + * We most definitely don't want callers attempting to + * allocate greater than order-1 page units with __GFP_NOFAIL. + */ + WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1)); + spin_lock_irqsave(&zone->lock, flags); + + do { + page = NULL; + if (alloc_flags & ALLOC_HARDER) { + page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC); + if (page) + trace_mm_page_alloc_zone_locked(page, order, migratetype); + } + if (!page) + page = __rmqueue(zone, order, migratetype); + } while (page && check_new_pages(page, order)); + spin_unlock(&zone->lock); + if (!page) + goto failed; + __mod_zone_freepage_state(zone, -(1 << order), + get_pcppage_migratetype(page)); + + __count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order); + zone_statistics(preferred_zone, zone); + local_irq_restore(flags); + +out: + VM_BUG_ON_PAGE(page && bad_range(zone, page), page); + return page; + +failed: + local_irq_restore(flags); + return NULL; +} + +#ifdef CONFIG_FAIL_PAGE_ALLOC + +static struct { + struct fault_attr attr; + + bool ignore_gfp_highmem; + bool ignore_gfp_reclaim; + u32 min_order; +} fail_page_alloc = { + .attr = FAULT_ATTR_INITIALIZER, + .ignore_gfp_reclaim = true, + .ignore_gfp_highmem = true, + .min_order = 1, +}; + +static int __init setup_fail_page_alloc(char *str) +{ + return setup_fault_attr(&fail_page_alloc.attr, str); +} +__setup("fail_page_alloc=", setup_fail_page_alloc); + +static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) +{ + if (order < fail_page_alloc.min_order) + return false; + if (gfp_mask & __GFP_NOFAIL) + return false; + if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM)) + return false; + if (fail_page_alloc.ignore_gfp_reclaim && + (gfp_mask & __GFP_DIRECT_RECLAIM)) + return false; + + return should_fail(&fail_page_alloc.attr, 1 << order); +} + +#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS + +static int __init fail_page_alloc_debugfs(void) +{ + umode_t mode = S_IFREG | 0600; + struct dentry *dir; + + dir = fault_create_debugfs_attr("fail_page_alloc", NULL, + &fail_page_alloc.attr); + if (IS_ERR(dir)) + return PTR_ERR(dir); + + if (!debugfs_create_bool("ignore-gfp-wait", mode, dir, + &fail_page_alloc.ignore_gfp_reclaim)) + goto fail; + if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir, + &fail_page_alloc.ignore_gfp_highmem)) + goto fail; + if (!debugfs_create_u32("min-order", mode, dir, + &fail_page_alloc.min_order)) + goto fail; + + return 0; +fail: + debugfs_remove_recursive(dir); + + return -ENOMEM; +} + +late_initcall(fail_page_alloc_debugfs); + +#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ + +#else /* CONFIG_FAIL_PAGE_ALLOC */ + +static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) +{ + return false; +} + +#endif /* CONFIG_FAIL_PAGE_ALLOC */ + +/* + * Return true if free base pages are above 'mark'. For high-order checks it + * will return true of the order-0 watermark is reached and there is at least + * one free page of a suitable size. Checking now avoids taking the zone lock + * to check in the allocation paths if no pages are free. + */ +bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, + int classzone_idx, unsigned int alloc_flags, + long free_pages) +{ + long min = mark; + int o; + const bool alloc_harder = (alloc_flags & (ALLOC_HARDER|ALLOC_OOM)); + + /* free_pages may go negative - that's OK */ + free_pages -= (1 << order) - 1; + + if (alloc_flags & ALLOC_HIGH) + min -= min / 2; + + /* + * If the caller does not have rights to ALLOC_HARDER then subtract + * the high-atomic reserves. This will over-estimate the size of the + * atomic reserve but it avoids a search. + */ + if (likely(!alloc_harder)) { + free_pages -= z->nr_reserved_highatomic; + } else { + /* + * OOM victims can try even harder than normal ALLOC_HARDER + * users on the grounds that it's definitely going to be in + * the exit path shortly and free memory. Any allocation it + * makes during the free path will be small and short-lived. + */ + if (alloc_flags & ALLOC_OOM) + min -= min / 2; + else + min -= min / 4; + } + + +#ifdef CONFIG_CMA + /* If allocation can't use CMA areas don't use free CMA pages */ + if (!(alloc_flags & ALLOC_CMA)) + free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES); +#endif + + /* + * Check watermarks for an order-0 allocation request. If these + * are not met, then a high-order request also cannot go ahead + * even if a suitable page happened to be free. + */ + if (free_pages <= min + z->lowmem_reserve[classzone_idx]) + return false; + + /* If this is an order-0 request then the watermark is fine */ + if (!order) + return true; + + /* For a high-order request, check at least one suitable page is free */ + for (o = order; o < MAX_ORDER; o++) { + struct free_area *area = &z->free_area[o]; + int mt; + + if (!area->nr_free) + continue; + + for (mt = 0; mt < MIGRATE_PCPTYPES; mt++) { + if (!list_empty(&area->free_list[mt])) + return true; + } + +#ifdef CONFIG_CMA + if ((alloc_flags & ALLOC_CMA) && + !list_empty(&area->free_list[MIGRATE_CMA])) { + return true; + } +#endif + if (alloc_harder && + !list_empty(&area->free_list[MIGRATE_HIGHATOMIC])) + return true; + } + return false; +} + +bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, + int classzone_idx, unsigned int alloc_flags) +{ + return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags, + zone_page_state(z, NR_FREE_PAGES)); +} + +static inline bool zone_watermark_fast(struct zone *z, unsigned int order, + unsigned long mark, int classzone_idx, unsigned int alloc_flags) +{ + long free_pages = zone_page_state(z, NR_FREE_PAGES); + long cma_pages = 0; + +#ifdef CONFIG_CMA + /* If allocation can't use CMA areas don't use free CMA pages */ + if (!(alloc_flags & ALLOC_CMA)) + cma_pages = zone_page_state(z, NR_FREE_CMA_PAGES); +#endif + + /* + * Fast check for order-0 only. If this fails then the reserves + * need to be calculated. There is a corner case where the check + * passes but only the high-order atomic reserve are free. If + * the caller is !atomic then it'll uselessly search the free + * list. That corner case is then slower but it is harmless. + */ + if (!order && (free_pages - cma_pages) > mark + z->lowmem_reserve[classzone_idx]) + return true; + + return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags, + free_pages); +} + +bool zone_watermark_ok_safe(struct zone *z, unsigned int order, + unsigned long mark, int classzone_idx) +{ + long free_pages = zone_page_state(z, NR_FREE_PAGES); + + if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark) + free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES); + + return __zone_watermark_ok(z, order, mark, classzone_idx, 0, + free_pages); +} + +#ifdef CONFIG_NUMA +static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone) +{ + return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <= + RECLAIM_DISTANCE; +} +#else /* CONFIG_NUMA */ +static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone) +{ + return true; +} +#endif /* CONFIG_NUMA */ + +/* + * get_page_from_freelist goes through the zonelist trying to allocate + * a page. + */ +static struct page * +get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags, + const struct alloc_context *ac) +{ + struct zoneref *z = ac->preferred_zoneref; + struct zone *zone; + struct pglist_data *last_pgdat_dirty_limit = NULL; + + /* + * Scan zonelist, looking for a zone with enough free. + * See also __cpuset_node_allowed() comment in kernel/cpuset.c. + */ + for_next_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx, + ac->nodemask) { + struct page *page; + unsigned long mark; + + if (cpusets_enabled() && + (alloc_flags & ALLOC_CPUSET) && + !__cpuset_zone_allowed(zone, gfp_mask)) + continue; + /* + * When allocating a page cache page for writing, we + * want to get it from a node that is within its dirty + * limit, such that no single node holds more than its + * proportional share of globally allowed dirty pages. + * The dirty limits take into account the node's + * lowmem reserves and high watermark so that kswapd + * should be able to balance it without having to + * write pages from its LRU list. + * + * XXX: For now, allow allocations to potentially + * exceed the per-node dirty limit in the slowpath + * (spread_dirty_pages unset) before going into reclaim, + * which is important when on a NUMA setup the allowed + * nodes are together not big enough to reach the + * global limit. The proper fix for these situations + * will require awareness of nodes in the + * dirty-throttling and the flusher threads. + */ + if (ac->spread_dirty_pages) { + if (last_pgdat_dirty_limit == zone->zone_pgdat) + continue; + + if (!node_dirty_ok(zone->zone_pgdat)) { + last_pgdat_dirty_limit = zone->zone_pgdat; + continue; + } + } + + mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK]; + if (!zone_watermark_fast(zone, order, mark, + ac_classzone_idx(ac), alloc_flags)) { + int ret; + +#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT + /* + * Watermark failed for this zone, but see if we can + * grow this zone if it contains deferred pages. + */ + if (static_branch_unlikely(&deferred_pages)) { + if (_deferred_grow_zone(zone, order)) + goto try_this_zone; + } +#endif + /* Checked here to keep the fast path fast */ + BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK); + if (alloc_flags & ALLOC_NO_WATERMARKS) + goto try_this_zone; + + if (node_reclaim_mode == 0 || + !zone_allows_reclaim(ac->preferred_zoneref->zone, zone)) + continue; + + ret = node_reclaim(zone->zone_pgdat, gfp_mask, order); + switch (ret) { + case NODE_RECLAIM_NOSCAN: + /* did not scan */ + continue; + case NODE_RECLAIM_FULL: + /* scanned but unreclaimable */ + continue; + default: + /* did we reclaim enough */ + if (zone_watermark_ok(zone, order, mark, + ac_classzone_idx(ac), alloc_flags)) + goto try_this_zone; + + continue; + } + } + +try_this_zone: + page = rmqueue(ac->preferred_zoneref->zone, zone, order, + gfp_mask, alloc_flags, ac->migratetype); + if (page) { + prep_new_page(page, order, gfp_mask, alloc_flags); + + /* + * If this is a high-order atomic allocation then check + * if the pageblock should be reserved for the future + */ + if (unlikely(order && (alloc_flags & ALLOC_HARDER))) + reserve_highatomic_pageblock(page, zone, order); + + return page; + } else { +#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT + /* Try again if zone has deferred pages */ + if (static_branch_unlikely(&deferred_pages)) { + if (_deferred_grow_zone(zone, order)) + goto try_this_zone; + } +#endif + } + } + + return NULL; +} + +/* + * Large machines with many possible nodes should not always dump per-node + * meminfo in irq context. + */ +static inline bool should_suppress_show_mem(void) +{ + bool ret = false; + +#if NODES_SHIFT > 8 + ret = in_interrupt(); +#endif + return ret; +} + +static void warn_alloc_show_mem(gfp_t gfp_mask, nodemask_t *nodemask) +{ + unsigned int filter = SHOW_MEM_FILTER_NODES; + static DEFINE_RATELIMIT_STATE(show_mem_rs, HZ, 1); + + if (should_suppress_show_mem() || !__ratelimit(&show_mem_rs)) + return; + + /* + * This documents exceptions given to allocations in certain + * contexts that are allowed to allocate outside current's set + * of allowed nodes. + */ + if (!(gfp_mask & __GFP_NOMEMALLOC)) + if (tsk_is_oom_victim(current) || + (current->flags & (PF_MEMALLOC | PF_EXITING))) + filter &= ~SHOW_MEM_FILTER_NODES; + if (in_interrupt() || !(gfp_mask & __GFP_DIRECT_RECLAIM)) + filter &= ~SHOW_MEM_FILTER_NODES; + + show_mem(filter, nodemask); +} + +void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + static DEFINE_RATELIMIT_STATE(nopage_rs, DEFAULT_RATELIMIT_INTERVAL, + DEFAULT_RATELIMIT_BURST); + + if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs)) + return; + + va_start(args, fmt); + vaf.fmt = fmt; + vaf.va = &args; + pr_warn("%s: %pV, mode:%#x(%pGg), nodemask=%*pbl\n", + current->comm, &vaf, gfp_mask, &gfp_mask, + nodemask_pr_args(nodemask)); + va_end(args); + + cpuset_print_current_mems_allowed(); + + dump_stack(); + warn_alloc_show_mem(gfp_mask, nodemask); +} + +static inline struct page * +__alloc_pages_cpuset_fallback(gfp_t gfp_mask, unsigned int order, + unsigned int alloc_flags, + const struct alloc_context *ac) +{ + struct page *page; + + page = get_page_from_freelist(gfp_mask, order, + alloc_flags|ALLOC_CPUSET, ac); + /* + * fallback to ignore cpuset restriction if our nodes + * are depleted + */ + if (!page) + page = get_page_from_freelist(gfp_mask, order, + alloc_flags, ac); + + return page; +} + +static inline struct page * +__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order, + const struct alloc_context *ac, unsigned long *did_some_progress) +{ + struct oom_control oc = { + .zonelist = ac->zonelist, + .nodemask = ac->nodemask, + .memcg = NULL, + .gfp_mask = gfp_mask, + .order = order, + }; + struct page *page; + + *did_some_progress = 0; + + /* + * Acquire the oom lock. If that fails, somebody else is + * making progress for us. + */ + if (!mutex_trylock(&oom_lock)) { + *did_some_progress = 1; + schedule_timeout_uninterruptible(1); + return NULL; + } + + /* + * Go through the zonelist yet one more time, keep very high watermark + * here, this is only to catch a parallel oom killing, we must fail if + * we're still under heavy pressure. But make sure that this reclaim + * attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY + * allocation which will never fail due to oom_lock already held. + */ + page = get_page_from_freelist((gfp_mask | __GFP_HARDWALL) & + ~__GFP_DIRECT_RECLAIM, order, + ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac); + if (page) + goto out; + + /* Coredumps can quickly deplete all memory reserves */ + if (current->flags & PF_DUMPCORE) + goto out; + /* The OOM killer will not help higher order allocs */ + if (order > PAGE_ALLOC_COSTLY_ORDER) + goto out; + /* + * We have already exhausted all our reclaim opportunities without any + * success so it is time to admit defeat. We will skip the OOM killer + * because it is very likely that the caller has a more reasonable + * fallback than shooting a random task. + */ + if (gfp_mask & __GFP_RETRY_MAYFAIL) + goto out; + /* The OOM killer does not needlessly kill tasks for lowmem */ + if (ac->high_zoneidx < ZONE_NORMAL) + goto out; + if (pm_suspended_storage()) + goto out; + /* + * XXX: GFP_NOFS allocations should rather fail than rely on + * other request to make a forward progress. + * We are in an unfortunate situation where out_of_memory cannot + * do much for this context but let's try it to at least get + * access to memory reserved if the current task is killed (see + * out_of_memory). Once filesystems are ready to handle allocation + * failures more gracefully we should just bail out here. + */ + + /* The OOM killer may not free memory on a specific node */ + if (gfp_mask & __GFP_THISNODE) + goto out; + + /* Exhausted what can be done so it's blame time */ + if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) { + *did_some_progress = 1; + + /* + * Help non-failing allocations by giving them access to memory + * reserves + */ + if (gfp_mask & __GFP_NOFAIL) + page = __alloc_pages_cpuset_fallback(gfp_mask, order, + ALLOC_NO_WATERMARKS, ac); + } +out: + mutex_unlock(&oom_lock); + return page; +} + +/* + * Maximum number of compaction retries wit a progress before OOM + * killer is consider as the only way to move forward. + */ +#define MAX_COMPACT_RETRIES 16 + +#ifdef CONFIG_COMPACTION +/* Try memory compaction for high-order allocations before reclaim */ +static struct page * +__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, + unsigned int alloc_flags, const struct alloc_context *ac, + enum compact_priority prio, enum compact_result *compact_result) +{ + struct page *page; + unsigned int noreclaim_flag; + + if (!order) + return NULL; + + noreclaim_flag = memalloc_noreclaim_save(); + *compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac, + prio); + memalloc_noreclaim_restore(noreclaim_flag); + + if (*compact_result <= COMPACT_INACTIVE) + return NULL; + + /* + * At least in one zone compaction wasn't deferred or skipped, so let's + * count a compaction stall + */ + count_vm_event(COMPACTSTALL); + + page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac); + + if (page) { + struct zone *zone = page_zone(page); + + zone->compact_blockskip_flush = false; + compaction_defer_reset(zone, order, true); + count_vm_event(COMPACTSUCCESS); + return page; + } + + /* + * It's bad if compaction run occurs and fails. The most likely reason + * is that pages exist, but not enough to satisfy watermarks. + */ + count_vm_event(COMPACTFAIL); + + cond_resched(); + + return NULL; +} + +static inline bool +should_compact_retry(struct alloc_context *ac, int order, int alloc_flags, + enum compact_result compact_result, + enum compact_priority *compact_priority, + int *compaction_retries) +{ + int max_retries = MAX_COMPACT_RETRIES; + int min_priority; + bool ret = false; + int retries = *compaction_retries; + enum compact_priority priority = *compact_priority; + + if (!order) + return false; + + if (compaction_made_progress(compact_result)) + (*compaction_retries)++; + + /* + * compaction considers all the zone as desperately out of memory + * so it doesn't really make much sense to retry except when the + * failure could be caused by insufficient priority + */ + if (compaction_failed(compact_result)) + goto check_priority; + + /* + * make sure the compaction wasn't deferred or didn't bail out early + * due to locks contention before we declare that we should give up. + * But do not retry if the given zonelist is not suitable for + * compaction. + */ + if (compaction_withdrawn(compact_result)) { + ret = compaction_zonelist_suitable(ac, order, alloc_flags); + goto out; + } + + /* + * !costly requests are much more important than __GFP_RETRY_MAYFAIL + * costly ones because they are de facto nofail and invoke OOM + * killer to move on while costly can fail and users are ready + * to cope with that. 1/4 retries is rather arbitrary but we + * would need much more detailed feedback from compaction to + * make a better decision. + */ + if (order > PAGE_ALLOC_COSTLY_ORDER) + max_retries /= 4; + if (*compaction_retries <= max_retries) { + ret = true; + goto out; + } + + /* + * Make sure there are attempts at the highest priority if we exhausted + * all retries or failed at the lower priorities. + */ +check_priority: + min_priority = (order > PAGE_ALLOC_COSTLY_ORDER) ? + MIN_COMPACT_COSTLY_PRIORITY : MIN_COMPACT_PRIORITY; + + if (*compact_priority > min_priority) { + (*compact_priority)--; + *compaction_retries = 0; + ret = true; + } +out: + trace_compact_retry(order, priority, compact_result, retries, max_retries, ret); + return ret; +} +#else +static inline struct page * +__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, + unsigned int alloc_flags, const struct alloc_context *ac, + enum compact_priority prio, enum compact_result *compact_result) +{ + *compact_result = COMPACT_SKIPPED; + return NULL; +} + +static inline bool +should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_flags, + enum compact_result compact_result, + enum compact_priority *compact_priority, + int *compaction_retries) +{ + struct zone *zone; + struct zoneref *z; + + if (!order || order > PAGE_ALLOC_COSTLY_ORDER) + return false; + + /* + * There are setups with compaction disabled which would prefer to loop + * inside the allocator rather than hit the oom killer prematurely. + * Let's give them a good hope and keep retrying while the order-0 + * watermarks are OK. + */ + for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx, + ac->nodemask) { + if (zone_watermark_ok(zone, 0, min_wmark_pages(zone), + ac_classzone_idx(ac), alloc_flags)) + return true; + } + return false; +} +#endif /* CONFIG_COMPACTION */ + +#ifdef CONFIG_LOCKDEP +static struct lockdep_map __fs_reclaim_map = + STATIC_LOCKDEP_MAP_INIT("fs_reclaim", &__fs_reclaim_map); + +static bool __need_fs_reclaim(gfp_t gfp_mask) +{ + gfp_mask = current_gfp_context(gfp_mask); + + /* no reclaim without waiting on it */ + if (!(gfp_mask & __GFP_DIRECT_RECLAIM)) + return false; + + /* this guy won't enter reclaim */ + if (current->flags & PF_MEMALLOC) + return false; + + /* We're only interested __GFP_FS allocations for now */ + if (!(gfp_mask & __GFP_FS)) + return false; + + if (gfp_mask & __GFP_NOLOCKDEP) + return false; + + return true; +} + +void __fs_reclaim_acquire(void) +{ + lock_map_acquire(&__fs_reclaim_map); +} + +void __fs_reclaim_release(void) +{ + lock_map_release(&__fs_reclaim_map); +} + +void fs_reclaim_acquire(gfp_t gfp_mask) +{ + if (__need_fs_reclaim(gfp_mask)) + __fs_reclaim_acquire(); +} +EXPORT_SYMBOL_GPL(fs_reclaim_acquire); + +void fs_reclaim_release(gfp_t gfp_mask) +{ + if (__need_fs_reclaim(gfp_mask)) + __fs_reclaim_release(); +} +EXPORT_SYMBOL_GPL(fs_reclaim_release); +#endif + +/* Perform direct synchronous page reclaim */ +static int +__perform_reclaim(gfp_t gfp_mask, unsigned int order, + const struct alloc_context *ac) +{ + struct reclaim_state reclaim_state; + int progress; + unsigned int noreclaim_flag; + + cond_resched(); + + /* We now go into synchronous reclaim */ + cpuset_memory_pressure_bump(); + fs_reclaim_acquire(gfp_mask); + noreclaim_flag = memalloc_noreclaim_save(); + reclaim_state.reclaimed_slab = 0; + current->reclaim_state = &reclaim_state; + + progress = try_to_free_pages(ac->zonelist, order, gfp_mask, + ac->nodemask); + + current->reclaim_state = NULL; + memalloc_noreclaim_restore(noreclaim_flag); + fs_reclaim_release(gfp_mask); + + cond_resched(); + + return progress; +} + +/* The really slow allocator path where we enter direct reclaim */ +static inline struct page * +__alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order, + unsigned int alloc_flags, const struct alloc_context *ac, + unsigned long *did_some_progress) +{ + struct page *page = NULL; + bool drained = false; + + *did_some_progress = __perform_reclaim(gfp_mask, order, ac); + if (unlikely(!(*did_some_progress))) + return NULL; + +retry: + page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac); + + /* + * If an allocation failed after direct reclaim, it could be because + * pages are pinned on the per-cpu lists or in high alloc reserves. + * Shrink them them and try again + */ + if (!page && !drained) { + unreserve_highatomic_pageblock(ac, false); + drain_all_pages(NULL); + drained = true; + goto retry; + } + + return page; +} + +static void wake_all_kswapds(unsigned int order, gfp_t gfp_mask, + const struct alloc_context *ac) +{ + struct zoneref *z; + struct zone *zone; + pg_data_t *last_pgdat = NULL; + enum zone_type high_zoneidx = ac->high_zoneidx; + + for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, high_zoneidx, + ac->nodemask) { + if (last_pgdat != zone->zone_pgdat) + wakeup_kswapd(zone, gfp_mask, order, high_zoneidx); + last_pgdat = zone->zone_pgdat; + } +} + +static inline unsigned int +gfp_to_alloc_flags(gfp_t gfp_mask) +{ + unsigned int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET; + + /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */ + BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH); + + /* + * The caller may dip into page reserves a bit more if the caller + * cannot run direct reclaim, or if the caller has realtime scheduling + * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will + * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH). + */ + alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH); + + if (gfp_mask & __GFP_ATOMIC) { + /* + * Not worth trying to allocate harder for __GFP_NOMEMALLOC even + * if it can't schedule. + */ + if (!(gfp_mask & __GFP_NOMEMALLOC)) + alloc_flags |= ALLOC_HARDER; + /* + * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the + * comment for __cpuset_node_allowed(). + */ + alloc_flags &= ~ALLOC_CPUSET; + } else if (unlikely(rt_task(current)) && !in_interrupt()) + alloc_flags |= ALLOC_HARDER; + +#ifdef CONFIG_CMA + if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE) + alloc_flags |= ALLOC_CMA; +#endif + return alloc_flags; +} + +static bool oom_reserves_allowed(struct task_struct *tsk) +{ + if (!tsk_is_oom_victim(tsk)) + return false; + + /* + * !MMU doesn't have oom reaper so give access to memory reserves + * only to the thread with TIF_MEMDIE set + */ + if (!IS_ENABLED(CONFIG_MMU) && !test_thread_flag(TIF_MEMDIE)) + return false; + + return true; +} + +/* + * Distinguish requests which really need access to full memory + * reserves from oom victims which can live with a portion of it + */ +static inline int __gfp_pfmemalloc_flags(gfp_t gfp_mask) +{ + if (unlikely(gfp_mask & __GFP_NOMEMALLOC)) + return 0; + if (gfp_mask & __GFP_MEMALLOC) + return ALLOC_NO_WATERMARKS; + if (in_serving_softirq() && (current->flags & PF_MEMALLOC)) + return ALLOC_NO_WATERMARKS; + if (!in_interrupt()) { + if (current->flags & PF_MEMALLOC) + return ALLOC_NO_WATERMARKS; + else if (oom_reserves_allowed(current)) + return ALLOC_OOM; + } + + return 0; +} + +bool gfp_pfmemalloc_allowed(gfp_t gfp_mask) +{ + return !!__gfp_pfmemalloc_flags(gfp_mask); +} + +/* + * Checks whether it makes sense to retry the reclaim to make a forward progress + * for the given allocation request. + * + * We give up when we either have tried MAX_RECLAIM_RETRIES in a row + * without success, or when we couldn't even meet the watermark if we + * reclaimed all remaining pages on the LRU lists. + * + * Returns true if a retry is viable or false to enter the oom path. + */ +static inline bool +should_reclaim_retry(gfp_t gfp_mask, unsigned order, + struct alloc_context *ac, int alloc_flags, + bool did_some_progress, int *no_progress_loops) +{ + struct zone *zone; + struct zoneref *z; + + /* + * Costly allocations might have made a progress but this doesn't mean + * their order will become available due to high fragmentation so + * always increment the no progress counter for them + */ + if (did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER) + *no_progress_loops = 0; + else + (*no_progress_loops)++; + + /* + * Make sure we converge to OOM if we cannot make any progress + * several times in the row. + */ + if (*no_progress_loops > MAX_RECLAIM_RETRIES) { + /* Before OOM, exhaust highatomic_reserve */ + return unreserve_highatomic_pageblock(ac, true); + } + + /* + * Keep reclaiming pages while there is a chance this will lead + * somewhere. If none of the target zones can satisfy our allocation + * request even if all reclaimable pages are considered then we are + * screwed and have to go OOM. + */ + for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx, + ac->nodemask) { + unsigned long available; + unsigned long reclaimable; + unsigned long min_wmark = min_wmark_pages(zone); + bool wmark; + + available = reclaimable = zone_reclaimable_pages(zone); + available += zone_page_state_snapshot(zone, NR_FREE_PAGES); + + /* + * Would the allocation succeed if we reclaimed all + * reclaimable pages? + */ + wmark = __zone_watermark_ok(zone, order, min_wmark, + ac_classzone_idx(ac), alloc_flags, available); + trace_reclaim_retry_zone(z, order, reclaimable, + available, min_wmark, *no_progress_loops, wmark); + if (wmark) { + /* + * If we didn't make any progress and have a lot of + * dirty + writeback pages then we should wait for + * an IO to complete to slow down the reclaim and + * prevent from pre mature OOM + */ + if (!did_some_progress) { + unsigned long write_pending; + + write_pending = zone_page_state_snapshot(zone, + NR_ZONE_WRITE_PENDING); + + if (2 * write_pending > reclaimable) { + congestion_wait(BLK_RW_ASYNC, HZ/10); + return true; + } + } + + /* + * Memory allocation/reclaim might be called from a WQ + * context and the current implementation of the WQ + * concurrency control doesn't recognize that + * a particular WQ is congested if the worker thread is + * looping without ever sleeping. Therefore we have to + * do a short sleep here rather than calling + * cond_resched(). + */ + if (current->flags & PF_WQ_WORKER) + schedule_timeout_uninterruptible(1); + else + cond_resched(); + + return true; + } + } + + return false; +} + +static inline bool +check_retry_cpuset(int cpuset_mems_cookie, struct alloc_context *ac) +{ + /* + * It's possible that cpuset's mems_allowed and the nodemask from + * mempolicy don't intersect. This should be normally dealt with by + * policy_nodemask(), but it's possible to race with cpuset update in + * such a way the check therein was true, and then it became false + * before we got our cpuset_mems_cookie here. + * This assumes that for all allocations, ac->nodemask can come only + * from MPOL_BIND mempolicy (whose documented semantics is to be ignored + * when it does not intersect with the cpuset restrictions) or the + * caller can deal with a violated nodemask. + */ + if (cpusets_enabled() && ac->nodemask && + !cpuset_nodemask_valid_mems_allowed(ac->nodemask)) { + ac->nodemask = NULL; + return true; + } + + /* + * When updating a task's mems_allowed or mempolicy nodemask, it is + * possible to race with parallel threads in such a way that our + * allocation can fail while the mask is being updated. If we are about + * to fail, check if the cpuset changed during allocation and if so, + * retry. + */ + if (read_mems_allowed_retry(cpuset_mems_cookie)) + return true; + + return false; +} + +static inline struct page * +__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, + struct alloc_context *ac) +{ + bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM; + const bool costly_order = order > PAGE_ALLOC_COSTLY_ORDER; + struct page *page = NULL; + unsigned int alloc_flags; + unsigned long did_some_progress; + enum compact_priority compact_priority; + enum compact_result compact_result; + int compaction_retries; + int no_progress_loops; + unsigned int cpuset_mems_cookie; + int reserve_flags; + + /* + * We also sanity check to catch abuse of atomic reserves being used by + * callers that are not in atomic context. + */ + if (WARN_ON_ONCE((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) == + (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM))) + gfp_mask &= ~__GFP_ATOMIC; + +retry_cpuset: + compaction_retries = 0; + no_progress_loops = 0; + compact_priority = DEF_COMPACT_PRIORITY; + cpuset_mems_cookie = read_mems_allowed_begin(); + + /* + * The fast path uses conservative alloc_flags to succeed only until + * kswapd needs to be woken up, and to avoid the cost of setting up + * alloc_flags precisely. So we do that now. + */ + alloc_flags = gfp_to_alloc_flags(gfp_mask); + + /* + * We need to recalculate the starting point for the zonelist iterator + * because we might have used different nodemask in the fast path, or + * there was a cpuset modification and we are retrying - otherwise we + * could end up iterating over non-eligible zones endlessly. + */ + ac->preferred_zoneref = first_zones_zonelist(ac->zonelist, + ac->high_zoneidx, ac->nodemask); + if (!ac->preferred_zoneref->zone) + goto nopage; + + if (gfp_mask & __GFP_KSWAPD_RECLAIM) + wake_all_kswapds(order, gfp_mask, ac); + + /* + * The adjusted alloc_flags might result in immediate success, so try + * that first + */ + page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac); + if (page) + goto got_pg; + + /* + * For costly allocations, try direct compaction first, as it's likely + * that we have enough base pages and don't need to reclaim. For non- + * movable high-order allocations, do that as well, as compaction will + * try prevent permanent fragmentation by migrating from blocks of the + * same migratetype. + * Don't try this for allocations that are allowed to ignore + * watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen. + */ + if (can_direct_reclaim && + (costly_order || + (order > 0 && ac->migratetype != MIGRATE_MOVABLE)) + && !gfp_pfmemalloc_allowed(gfp_mask)) { + page = __alloc_pages_direct_compact(gfp_mask, order, + alloc_flags, ac, + INIT_COMPACT_PRIORITY, + &compact_result); + if (page) + goto got_pg; + + /* + * Checks for costly allocations with __GFP_NORETRY, which + * includes THP page fault allocations + */ + if (costly_order && (gfp_mask & __GFP_NORETRY)) { + /* + * If compaction is deferred for high-order allocations, + * it is because sync compaction recently failed. If + * this is the case and the caller requested a THP + * allocation, we do not want to heavily disrupt the + * system, so we fail the allocation instead of entering + * direct reclaim. + */ + if (compact_result == COMPACT_DEFERRED) + goto nopage; + + /* + * Looks like reclaim/compaction is worth trying, but + * sync compaction could be very expensive, so keep + * using async compaction. + */ + compact_priority = INIT_COMPACT_PRIORITY; + } + } + +retry: + /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */ + if (gfp_mask & __GFP_KSWAPD_RECLAIM) + wake_all_kswapds(order, gfp_mask, ac); + + reserve_flags = __gfp_pfmemalloc_flags(gfp_mask); + if (reserve_flags) + alloc_flags = reserve_flags; + + /* + * Reset the nodemask and zonelist iterators if memory policies can be + * ignored. These allocations are high priority and system rather than + * user oriented. + */ + if (!(alloc_flags & ALLOC_CPUSET) || reserve_flags) { + ac->nodemask = NULL; + ac->preferred_zoneref = first_zones_zonelist(ac->zonelist, + ac->high_zoneidx, ac->nodemask); + } + + /* Attempt with potentially adjusted zonelist and alloc_flags */ + page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac); + if (page) + goto got_pg; + + /* Caller is not willing to reclaim, we can't balance anything */ + if (!can_direct_reclaim) + goto nopage; + + /* Avoid recursion of direct reclaim */ + if (current->flags & PF_MEMALLOC) + goto nopage; + + /* Try direct reclaim and then allocating */ + page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac, + &did_some_progress); + if (page) + goto got_pg; + + /* Try direct compaction and then allocating */ + page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac, + compact_priority, &compact_result); + if (page) + goto got_pg; + + /* Do not loop if specifically requested */ + if (gfp_mask & __GFP_NORETRY) + goto nopage; + + /* + * Do not retry costly high order allocations unless they are + * __GFP_RETRY_MAYFAIL + */ + if (costly_order && !(gfp_mask & __GFP_RETRY_MAYFAIL)) + goto nopage; + + if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags, + did_some_progress > 0, &no_progress_loops)) + goto retry; + + /* + * It doesn't make any sense to retry for the compaction if the order-0 + * reclaim is not able to make any progress because the current + * implementation of the compaction depends on the sufficient amount + * of free memory (see __compaction_suitable) + */ + if (did_some_progress > 0 && + should_compact_retry(ac, order, alloc_flags, + compact_result, &compact_priority, + &compaction_retries)) + goto retry; + + + /* Deal with possible cpuset update races before we start OOM killing */ + if (check_retry_cpuset(cpuset_mems_cookie, ac)) + goto retry_cpuset; + + /* Reclaim has failed us, start killing things */ + page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress); + if (page) + goto got_pg; + + /* Avoid allocations with no watermarks from looping endlessly */ + if (tsk_is_oom_victim(current) && + (alloc_flags == ALLOC_OOM || + (gfp_mask & __GFP_NOMEMALLOC))) + goto nopage; + + /* Retry as long as the OOM killer is making progress */ + if (did_some_progress) { + no_progress_loops = 0; + goto retry; + } + +nopage: + /* Deal with possible cpuset update races before we fail */ + if (check_retry_cpuset(cpuset_mems_cookie, ac)) + goto retry_cpuset; + + /* + * Make sure that __GFP_NOFAIL request doesn't leak out and make sure + * we always retry + */ + if (gfp_mask & __GFP_NOFAIL) { + /* + * All existing users of the __GFP_NOFAIL are blockable, so warn + * of any new users that actually require GFP_NOWAIT + */ + if (WARN_ON_ONCE(!can_direct_reclaim)) + goto fail; + + /* + * PF_MEMALLOC request from this context is rather bizarre + * because we cannot reclaim anything and only can loop waiting + * for somebody to do a work for us + */ + WARN_ON_ONCE(current->flags & PF_MEMALLOC); + + /* + * non failing costly orders are a hard requirement which we + * are not prepared for much so let's warn about these users + * so that we can identify them and convert them to something + * else. + */ + WARN_ON_ONCE(order > PAGE_ALLOC_COSTLY_ORDER); + + /* + * Help non-failing allocations by giving them access to memory + * reserves but do not use ALLOC_NO_WATERMARKS because this + * could deplete whole memory reserves which would just make + * the situation worse + */ + page = __alloc_pages_cpuset_fallback(gfp_mask, order, ALLOC_HARDER, ac); + if (page) + goto got_pg; + + cond_resched(); + goto retry; + } +fail: + warn_alloc(gfp_mask, ac->nodemask, + "page allocation failure: order:%u", order); +got_pg: + return page; +} + +static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order, + int preferred_nid, nodemask_t *nodemask, + struct alloc_context *ac, gfp_t *alloc_mask, + unsigned int *alloc_flags) +{ + ac->high_zoneidx = gfp_zone(gfp_mask); + ac->zonelist = node_zonelist(preferred_nid, gfp_mask); + ac->nodemask = nodemask; + ac->migratetype = gfpflags_to_migratetype(gfp_mask); + + if (cpusets_enabled()) { + *alloc_mask |= __GFP_HARDWALL; + if (!ac->nodemask) + ac->nodemask = &cpuset_current_mems_allowed; + else + *alloc_flags |= ALLOC_CPUSET; + } + + fs_reclaim_acquire(gfp_mask); + fs_reclaim_release(gfp_mask); + + might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM); + + if (should_fail_alloc_page(gfp_mask, order)) + return false; + + if (IS_ENABLED(CONFIG_CMA) && ac->migratetype == MIGRATE_MOVABLE) + *alloc_flags |= ALLOC_CMA; + + return true; +} + +/* Determine whether to spread dirty pages and what the first usable zone */ +static inline void finalise_ac(gfp_t gfp_mask, struct alloc_context *ac) +{ + /* Dirty zone balancing only done in the fast path */ + ac->spread_dirty_pages = (gfp_mask & __GFP_WRITE); + + /* + * The preferred zone is used for statistics but crucially it is + * also used as the starting point for the zonelist iterator. It + * may get reset for allocations that ignore memory policies. + */ + ac->preferred_zoneref = first_zones_zonelist(ac->zonelist, + ac->high_zoneidx, ac->nodemask); +} + +/* + * This is the 'heart' of the zoned buddy allocator. + */ +struct page * +__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int preferred_nid, + nodemask_t *nodemask) +{ + struct page *page; + unsigned int alloc_flags = ALLOC_WMARK_LOW; + gfp_t alloc_mask; /* The gfp_t that was actually used for allocation */ + struct alloc_context ac = { }; + + /* + * There are several places where we assume that the order value is sane + * so bail out early if the request is out of bound. + */ + if (unlikely(order >= MAX_ORDER)) { + WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN)); + return NULL; + } + + gfp_mask &= gfp_allowed_mask; + alloc_mask = gfp_mask; + if (!prepare_alloc_pages(gfp_mask, order, preferred_nid, nodemask, &ac, &alloc_mask, &alloc_flags)) + return NULL; + + finalise_ac(gfp_mask, &ac); + + /* First allocation attempt */ + page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac); + if (likely(page)) + goto out; + + /* + * Apply scoped allocation constraints. This is mainly about GFP_NOFS + * resp. GFP_NOIO which has to be inherited for all allocation requests + * from a particular context which has been marked by + * memalloc_no{fs,io}_{save,restore}. + */ + alloc_mask = current_gfp_context(gfp_mask); + ac.spread_dirty_pages = false; + + /* + * Restore the original nodemask if it was potentially replaced with + * &cpuset_current_mems_allowed to optimize the fast-path attempt. + */ + if (unlikely(ac.nodemask != nodemask)) + ac.nodemask = nodemask; + + page = __alloc_pages_slowpath(alloc_mask, order, &ac); + +out: + if (memcg_kmem_enabled() && (gfp_mask & __GFP_ACCOUNT) && page && + unlikely(memcg_kmem_charge(page, gfp_mask, order) != 0)) { + __free_pages(page, order); + page = NULL; + } + + trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype); + + return page; +} +EXPORT_SYMBOL(__alloc_pages_nodemask); + +/* + * Common helper functions. Never use with __GFP_HIGHMEM because the returned + * address cannot represent highmem pages. Use alloc_pages and then kmap if + * you need to access high mem. + */ +unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) +{ + struct page *page; + + page = alloc_pages(gfp_mask & ~__GFP_HIGHMEM, order); + if (!page) + return 0; + return (unsigned long) page_address(page); +} +EXPORT_SYMBOL(__get_free_pages); + +unsigned long get_zeroed_page(gfp_t gfp_mask) +{ + return __get_free_pages(gfp_mask | __GFP_ZERO, 0); +} +EXPORT_SYMBOL(get_zeroed_page); + +static inline void free_the_page(struct page *page, unsigned int order) +{ + if (order == 0) /* Via pcp? */ + free_unref_page(page); + else + __free_pages_ok(page, order); +} + +void __free_pages(struct page *page, unsigned int order) +{ + if (put_page_testzero(page)) + free_the_page(page, order); +} +EXPORT_SYMBOL(__free_pages); + +void free_pages(unsigned long addr, unsigned int order) +{ + if (addr != 0) { + VM_BUG_ON(!virt_addr_valid((void *)addr)); + __free_pages(virt_to_page((void *)addr), order); + } +} + +EXPORT_SYMBOL(free_pages); + +/* + * Page Fragment: + * An arbitrary-length arbitrary-offset area of memory which resides + * within a 0 or higher order page. Multiple fragments within that page + * are individually refcounted, in the page's reference counter. + * + * The page_frag functions below provide a simple allocation framework for + * page fragments. This is used by the network stack and network device + * drivers to provide a backing region of memory for use as either an + * sk_buff->head, or to be used in the "frags" portion of skb_shared_info. + */ +static struct page *__page_frag_cache_refill(struct page_frag_cache *nc, + gfp_t gfp_mask) +{ + struct page *page = NULL; + gfp_t gfp = gfp_mask; + +#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) + gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY | + __GFP_NOMEMALLOC; + page = alloc_pages_node(NUMA_NO_NODE, gfp_mask, + PAGE_FRAG_CACHE_MAX_ORDER); + nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE; +#endif + if (unlikely(!page)) + page = alloc_pages_node(NUMA_NO_NODE, gfp, 0); + + nc->va = page ? page_address(page) : NULL; + + return page; +} + +void __page_frag_cache_drain(struct page *page, unsigned int count) +{ + VM_BUG_ON_PAGE(page_ref_count(page) == 0, page); + + if (page_ref_sub_and_test(page, count)) + free_the_page(page, compound_order(page)); +} +EXPORT_SYMBOL(__page_frag_cache_drain); + +void *page_frag_alloc(struct page_frag_cache *nc, + unsigned int fragsz, gfp_t gfp_mask) +{ + unsigned int size = PAGE_SIZE; + struct page *page; + int offset; + + if (unlikely(!nc->va)) { +refill: + page = __page_frag_cache_refill(nc, gfp_mask); + if (!page) + return NULL; + +#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) + /* if size can vary use size else just use PAGE_SIZE */ + size = nc->size; +#endif + /* Even if we own the page, we do not use atomic_set(). + * This would break get_page_unless_zero() users. + */ + page_ref_add(page, PAGE_FRAG_CACHE_MAX_SIZE); + + /* reset page count bias and offset to start of new frag */ + nc->pfmemalloc = page_is_pfmemalloc(page); + nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1; + nc->offset = size; + } + + offset = nc->offset - fragsz; + if (unlikely(offset < 0)) { + page = virt_to_page(nc->va); + + if (!page_ref_sub_and_test(page, nc->pagecnt_bias)) + goto refill; + + if (unlikely(nc->pfmemalloc)) { + free_the_page(page, compound_order(page)); + goto refill; + } + +#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) + /* if size can vary use size else just use PAGE_SIZE */ + size = nc->size; +#endif + /* OK, page count is 0, we can safely set it */ + set_page_count(page, PAGE_FRAG_CACHE_MAX_SIZE + 1); + + /* reset page count bias and offset to start of new frag */ + nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1; + offset = size - fragsz; + } + + nc->pagecnt_bias--; + nc->offset = offset; + + return nc->va + offset; +} +EXPORT_SYMBOL(page_frag_alloc); + +/* + * Frees a page fragment allocated out of either a compound or order 0 page. + */ +void page_frag_free(void *addr) +{ + struct page *page = virt_to_head_page(addr); + + if (unlikely(put_page_testzero(page))) + free_the_page(page, compound_order(page)); +} +EXPORT_SYMBOL(page_frag_free); + +static void *make_alloc_exact(unsigned long addr, unsigned int order, + size_t size) +{ + if (addr) { + unsigned long alloc_end = addr + (PAGE_SIZE << order); + unsigned long used = addr + PAGE_ALIGN(size); + + split_page(virt_to_page((void *)addr), order); + while (used < alloc_end) { + free_page(used); + used += PAGE_SIZE; + } + } + return (void *)addr; +} + +/** + * alloc_pages_exact - allocate an exact number physically-contiguous pages. + * @size: the number of bytes to allocate + * @gfp_mask: GFP flags for the allocation + * + * This function is similar to alloc_pages(), except that it allocates the + * minimum number of pages to satisfy the request. alloc_pages() can only + * allocate memory in power-of-two pages. + * + * This function is also limited by MAX_ORDER. + * + * Memory allocated by this function must be released by free_pages_exact(). + */ +void *alloc_pages_exact(size_t size, gfp_t gfp_mask) +{ + unsigned int order = get_order(size); + unsigned long addr; + + addr = __get_free_pages(gfp_mask, order); + return make_alloc_exact(addr, order, size); +} +EXPORT_SYMBOL(alloc_pages_exact); + +/** + * alloc_pages_exact_nid - allocate an exact number of physically-contiguous + * pages on a node. + * @nid: the preferred node ID where memory should be allocated + * @size: the number of bytes to allocate + * @gfp_mask: GFP flags for the allocation + * + * Like alloc_pages_exact(), but try to allocate on node nid first before falling + * back. + */ +void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask) +{ + unsigned int order = get_order(size); + struct page *p = alloc_pages_node(nid, gfp_mask, order); + if (!p) + return NULL; + return make_alloc_exact((unsigned long)page_address(p), order, size); +} + +/** + * free_pages_exact - release memory allocated via alloc_pages_exact() + * @virt: the value returned by alloc_pages_exact. + * @size: size of allocation, same value as passed to alloc_pages_exact(). + * + * Release the memory allocated by a previous call to alloc_pages_exact. + */ +void free_pages_exact(void *virt, size_t size) +{ + unsigned long addr = (unsigned long)virt; + unsigned long end = addr + PAGE_ALIGN(size); + + while (addr < end) { + free_page(addr); + addr += PAGE_SIZE; + } +} +EXPORT_SYMBOL(free_pages_exact); + +/** + * nr_free_zone_pages - count number of pages beyond high watermark + * @offset: The zone index of the highest zone + * + * nr_free_zone_pages() counts the number of counts pages which are beyond the + * high watermark within all zones at or below a given zone index. For each + * zone, the number of pages is calculated as: + * + * nr_free_zone_pages = managed_pages - high_pages + */ +static unsigned long nr_free_zone_pages(int offset) +{ + struct zoneref *z; + struct zone *zone; + + /* Just pick one node, since fallback list is circular */ + unsigned long sum = 0; + + struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL); + + for_each_zone_zonelist(zone, z, zonelist, offset) { + unsigned long size = zone->managed_pages; + unsigned long high = high_wmark_pages(zone); + if (size > high) + sum += size - high; + } + + return sum; +} + +/** + * nr_free_buffer_pages - count number of pages beyond high watermark + * + * nr_free_buffer_pages() counts the number of pages which are beyond the high + * watermark within ZONE_DMA and ZONE_NORMAL. + */ +unsigned long nr_free_buffer_pages(void) +{ + return nr_free_zone_pages(gfp_zone(GFP_USER)); +} +EXPORT_SYMBOL_GPL(nr_free_buffer_pages); + +/** + * nr_free_pagecache_pages - count number of pages beyond high watermark + * + * nr_free_pagecache_pages() counts the number of pages which are beyond the + * high watermark within all zones. + */ +unsigned long nr_free_pagecache_pages(void) +{ + return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE)); +} + +static inline void show_node(struct zone *zone) +{ + if (IS_ENABLED(CONFIG_NUMA)) + printk("Node %d ", zone_to_nid(zone)); +} + +long si_mem_available(void) +{ + long available; + unsigned long pagecache; + unsigned long wmark_low = 0; + unsigned long pages[NR_LRU_LISTS]; + struct zone *zone; + int lru; + + for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++) + pages[lru] = global_node_page_state(NR_LRU_BASE + lru); + + for_each_zone(zone) + wmark_low += zone->watermark[WMARK_LOW]; + + /* + * Estimate the amount of memory available for userspace allocations, + * without causing swapping. + */ + available = global_zone_page_state(NR_FREE_PAGES) - totalreserve_pages; + + /* + * Not all the page cache can be freed, otherwise the system will + * start swapping. Assume at least half of the page cache, or the + * low watermark worth of cache, needs to stay. + */ + pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE]; + pagecache -= min(pagecache / 2, wmark_low); + available += pagecache; + + /* + * Part of the reclaimable slab consists of items that are in use, + * and cannot be freed. Cap this estimate at the low watermark. + */ + available += global_node_page_state(NR_SLAB_RECLAIMABLE) - + min(global_node_page_state(NR_SLAB_RECLAIMABLE) / 2, + wmark_low); + + /* + * Part of the kernel memory, which can be released under memory + * pressure. + */ + available += global_node_page_state(NR_INDIRECTLY_RECLAIMABLE_BYTES) >> + PAGE_SHIFT; + + if (available < 0) + available = 0; + return available; +} +EXPORT_SYMBOL_GPL(si_mem_available); + +void si_meminfo(struct sysinfo *val) +{ + val->totalram = totalram_pages; + val->sharedram = global_node_page_state(NR_SHMEM); + val->freeram = global_zone_page_state(NR_FREE_PAGES); + val->bufferram = nr_blockdev_pages(); + val->totalhigh = totalhigh_pages; + val->freehigh = nr_free_highpages(); + val->mem_unit = PAGE_SIZE; +} + +EXPORT_SYMBOL(si_meminfo); + +#ifdef CONFIG_NUMA +void si_meminfo_node(struct sysinfo *val, int nid) +{ + int zone_type; /* needs to be signed */ + unsigned long managed_pages = 0; + unsigned long managed_highpages = 0; + unsigned long free_highpages = 0; + pg_data_t *pgdat = NODE_DATA(nid); + + for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) + managed_pages += pgdat->node_zones[zone_type].managed_pages; + val->totalram = managed_pages; + val->sharedram = node_page_state(pgdat, NR_SHMEM); + val->freeram = sum_zone_node_page_state(nid, NR_FREE_PAGES); +#ifdef CONFIG_HIGHMEM + for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { + struct zone *zone = &pgdat->node_zones[zone_type]; + + if (is_highmem(zone)) { + managed_highpages += zone->managed_pages; + free_highpages += zone_page_state(zone, NR_FREE_PAGES); + } + } + val->totalhigh = managed_highpages; + val->freehigh = free_highpages; +#else + val->totalhigh = managed_highpages; + val->freehigh = free_highpages; +#endif + val->mem_unit = PAGE_SIZE; +} +#endif + +/* + * Determine whether the node should be displayed or not, depending on whether + * SHOW_MEM_FILTER_NODES was passed to show_free_areas(). + */ +static bool show_mem_node_skip(unsigned int flags, int nid, nodemask_t *nodemask) +{ + if (!(flags & SHOW_MEM_FILTER_NODES)) + return false; + + /* + * no node mask - aka implicit memory numa policy. Do not bother with + * the synchronization - read_mems_allowed_begin - because we do not + * have to be precise here. + */ + if (!nodemask) + nodemask = &cpuset_current_mems_allowed; + + return !node_isset(nid, *nodemask); +} + +#define K(x) ((x) << (PAGE_SHIFT-10)) + +static void show_migration_types(unsigned char type) +{ + static const char types[MIGRATE_TYPES] = { + [MIGRATE_UNMOVABLE] = 'U', + [MIGRATE_MOVABLE] = 'M', + [MIGRATE_RECLAIMABLE] = 'E', + [MIGRATE_HIGHATOMIC] = 'H', +#ifdef CONFIG_CMA + [MIGRATE_CMA] = 'C', +#endif +#ifdef CONFIG_MEMORY_ISOLATION + [MIGRATE_ISOLATE] = 'I', +#endif + }; + char tmp[MIGRATE_TYPES + 1]; + char *p = tmp; + int i; + + for (i = 0; i < MIGRATE_TYPES; i++) { + if (type & (1 << i)) + *p++ = types[i]; + } + + *p = '\0'; + printk(KERN_CONT "(%s) ", tmp); +} + +/* + * Show free area list (used inside shift_scroll-lock stuff) + * We also calculate the percentage fragmentation. We do this by counting the + * memory on each free list with the exception of the first item on the list. + * + * Bits in @filter: + * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's + * cpuset. + */ +void show_free_areas(unsigned int filter, nodemask_t *nodemask) +{ + unsigned long free_pcp = 0; + int cpu; + struct zone *zone; + pg_data_t *pgdat; + + for_each_populated_zone(zone) { + if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask)) + continue; + + for_each_online_cpu(cpu) + free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count; + } + + printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n" + " active_file:%lu inactive_file:%lu isolated_file:%lu\n" + " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n" + " slab_reclaimable:%lu slab_unreclaimable:%lu\n" + " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n" + " free:%lu free_pcp:%lu free_cma:%lu\n", + global_node_page_state(NR_ACTIVE_ANON), + global_node_page_state(NR_INACTIVE_ANON), + global_node_page_state(NR_ISOLATED_ANON), + global_node_page_state(NR_ACTIVE_FILE), + global_node_page_state(NR_INACTIVE_FILE), + global_node_page_state(NR_ISOLATED_FILE), + global_node_page_state(NR_UNEVICTABLE), + global_node_page_state(NR_FILE_DIRTY), + global_node_page_state(NR_WRITEBACK), + global_node_page_state(NR_UNSTABLE_NFS), + global_node_page_state(NR_SLAB_RECLAIMABLE), + global_node_page_state(NR_SLAB_UNRECLAIMABLE), + global_node_page_state(NR_FILE_MAPPED), + global_node_page_state(NR_SHMEM), + global_zone_page_state(NR_PAGETABLE), + global_zone_page_state(NR_BOUNCE), + global_zone_page_state(NR_FREE_PAGES), + free_pcp, + global_zone_page_state(NR_FREE_CMA_PAGES)); + + for_each_online_pgdat(pgdat) { + if (show_mem_node_skip(filter, pgdat->node_id, nodemask)) + continue; + + printk("Node %d" + " active_anon:%lukB" + " inactive_anon:%lukB" + " active_file:%lukB" + " inactive_file:%lukB" + " unevictable:%lukB" + " isolated(anon):%lukB" + " isolated(file):%lukB" + " mapped:%lukB" + " dirty:%lukB" + " writeback:%lukB" + " shmem:%lukB" +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + " shmem_thp: %lukB" + " shmem_pmdmapped: %lukB" + " anon_thp: %lukB" +#endif + " writeback_tmp:%lukB" + " unstable:%lukB" + " all_unreclaimable? %s" + "\n", + pgdat->node_id, + K(node_page_state(pgdat, NR_ACTIVE_ANON)), + K(node_page_state(pgdat, NR_INACTIVE_ANON)), + K(node_page_state(pgdat, NR_ACTIVE_FILE)), + K(node_page_state(pgdat, NR_INACTIVE_FILE)), + K(node_page_state(pgdat, NR_UNEVICTABLE)), + K(node_page_state(pgdat, NR_ISOLATED_ANON)), + K(node_page_state(pgdat, NR_ISOLATED_FILE)), + K(node_page_state(pgdat, NR_FILE_MAPPED)), + K(node_page_state(pgdat, NR_FILE_DIRTY)), + K(node_page_state(pgdat, NR_WRITEBACK)), + K(node_page_state(pgdat, NR_SHMEM)), +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + K(node_page_state(pgdat, NR_SHMEM_THPS) * HPAGE_PMD_NR), + K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED) + * HPAGE_PMD_NR), + K(node_page_state(pgdat, NR_ANON_THPS) * HPAGE_PMD_NR), +#endif + K(node_page_state(pgdat, NR_WRITEBACK_TEMP)), + K(node_page_state(pgdat, NR_UNSTABLE_NFS)), + pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES ? + "yes" : "no"); + } + + for_each_populated_zone(zone) { + int i; + + if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask)) + continue; + + free_pcp = 0; + for_each_online_cpu(cpu) + free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count; + + show_node(zone); + printk(KERN_CONT + "%s" + " free:%lukB" + " min:%lukB" + " low:%lukB" + " high:%lukB" + " active_anon:%lukB" + " inactive_anon:%lukB" + " active_file:%lukB" + " inactive_file:%lukB" + " unevictable:%lukB" + " writepending:%lukB" + " present:%lukB" + " managed:%lukB" + " mlocked:%lukB" + " kernel_stack:%lukB" + " pagetables:%lukB" + " bounce:%lukB" + " free_pcp:%lukB" + " local_pcp:%ukB" + " free_cma:%lukB" + "\n", + zone->name, + K(zone_page_state(zone, NR_FREE_PAGES)), + K(min_wmark_pages(zone)), + K(low_wmark_pages(zone)), + K(high_wmark_pages(zone)), + K(zone_page_state(zone, NR_ZONE_ACTIVE_ANON)), + K(zone_page_state(zone, NR_ZONE_INACTIVE_ANON)), + K(zone_page_state(zone, NR_ZONE_ACTIVE_FILE)), + K(zone_page_state(zone, NR_ZONE_INACTIVE_FILE)), + K(zone_page_state(zone, NR_ZONE_UNEVICTABLE)), + K(zone_page_state(zone, NR_ZONE_WRITE_PENDING)), + K(zone->present_pages), + K(zone->managed_pages), + K(zone_page_state(zone, NR_MLOCK)), + zone_page_state(zone, NR_KERNEL_STACK_KB), + K(zone_page_state(zone, NR_PAGETABLE)), + K(zone_page_state(zone, NR_BOUNCE)), + K(free_pcp), + K(this_cpu_read(zone->pageset->pcp.count)), + K(zone_page_state(zone, NR_FREE_CMA_PAGES))); + printk("lowmem_reserve[]:"); + for (i = 0; i < MAX_NR_ZONES; i++) + printk(KERN_CONT " %ld", zone->lowmem_reserve[i]); + printk(KERN_CONT "\n"); + } + + for_each_populated_zone(zone) { + unsigned int order; + unsigned long nr[MAX_ORDER], flags, total = 0; + unsigned char types[MAX_ORDER]; + + if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask)) + continue; + show_node(zone); + printk(KERN_CONT "%s: ", zone->name); + + spin_lock_irqsave(&zone->lock, flags); + for (order = 0; order < MAX_ORDER; order++) { + struct free_area *area = &zone->free_area[order]; + int type; + + nr[order] = area->nr_free; + total += nr[order] << order; + + types[order] = 0; + for (type = 0; type < MIGRATE_TYPES; type++) { + if (!list_empty(&area->free_list[type])) + types[order] |= 1 << type; + } + } + spin_unlock_irqrestore(&zone->lock, flags); + for (order = 0; order < MAX_ORDER; order++) { + printk(KERN_CONT "%lu*%lukB ", + nr[order], K(1UL) << order); + if (nr[order]) + show_migration_types(types[order]); + } + printk(KERN_CONT "= %lukB\n", K(total)); + } + + hugetlb_show_meminfo(); + + printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES)); + + show_swap_cache_info(); +} + +static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref) +{ + zoneref->zone = zone; + zoneref->zone_idx = zone_idx(zone); +} + +/* + * Builds allocation fallback zone lists. + * + * Add all populated zones of a node to the zonelist. + */ +static int build_zonerefs_node(pg_data_t *pgdat, struct zoneref *zonerefs) +{ + struct zone *zone; + enum zone_type zone_type = MAX_NR_ZONES; + int nr_zones = 0; + + do { + zone_type--; + zone = pgdat->node_zones + zone_type; + if (populated_zone(zone)) { + zoneref_set_zone(zone, &zonerefs[nr_zones++]); + check_highest_zone(zone_type); + } + } while (zone_type); + + return nr_zones; +} + +#ifdef CONFIG_NUMA + +static int __parse_numa_zonelist_order(char *s) +{ + /* + * We used to support different zonlists modes but they turned + * out to be just not useful. Let's keep the warning in place + * if somebody still use the cmd line parameter so that we do + * not fail it silently + */ + if (!(*s == 'd' || *s == 'D' || *s == 'n' || *s == 'N')) { + pr_warn("Ignoring unsupported numa_zonelist_order value: %s\n", s); + return -EINVAL; + } + return 0; +} + +static __init int setup_numa_zonelist_order(char *s) +{ + if (!s) + return 0; + + return __parse_numa_zonelist_order(s); +} +early_param("numa_zonelist_order", setup_numa_zonelist_order); + +char numa_zonelist_order[] = "Node"; + +/* + * sysctl handler for numa_zonelist_order + */ +int numa_zonelist_order_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *length, + loff_t *ppos) +{ + char *str; + int ret; + + if (!write) + return proc_dostring(table, write, buffer, length, ppos); + str = memdup_user_nul(buffer, 16); + if (IS_ERR(str)) + return PTR_ERR(str); + + ret = __parse_numa_zonelist_order(str); + kfree(str); + return ret; +} + + +#define MAX_NODE_LOAD (nr_online_nodes) +static int node_load[MAX_NUMNODES]; + +/** + * find_next_best_node - find the next node that should appear in a given node's fallback list + * @node: node whose fallback list we're appending + * @used_node_mask: nodemask_t of already used nodes + * + * We use a number of factors to determine which is the next node that should + * appear on a given node's fallback list. The node should not have appeared + * already in @node's fallback list, and it should be the next closest node + * according to the distance array (which contains arbitrary distance values + * from each node to each node in the system), and should also prefer nodes + * with no CPUs, since presumably they'll have very little allocation pressure + * on them otherwise. + * It returns -1 if no node is found. + */ +static int find_next_best_node(int node, nodemask_t *used_node_mask) +{ + int n, val; + int min_val = INT_MAX; + int best_node = NUMA_NO_NODE; + const struct cpumask *tmp = cpumask_of_node(0); + + /* Use the local node if we haven't already */ + if (!node_isset(node, *used_node_mask)) { + node_set(node, *used_node_mask); + return node; + } + + for_each_node_state(n, N_MEMORY) { + + /* Don't want a node to appear more than once */ + if (node_isset(n, *used_node_mask)) + continue; + + /* Use the distance array to find the distance */ + val = node_distance(node, n); + + /* Penalize nodes under us ("prefer the next node") */ + val += (n < node); + + /* Give preference to headless and unused nodes */ + tmp = cpumask_of_node(n); + if (!cpumask_empty(tmp)) + val += PENALTY_FOR_NODE_WITH_CPUS; + + /* Slight preference for less loaded node */ + val *= (MAX_NODE_LOAD*MAX_NUMNODES); + val += node_load[n]; + + if (val < min_val) { + min_val = val; + best_node = n; + } + } + + if (best_node >= 0) + node_set(best_node, *used_node_mask); + + return best_node; +} + + +/* + * Build zonelists ordered by node and zones within node. + * This results in maximum locality--normal zone overflows into local + * DMA zone, if any--but risks exhausting DMA zone. + */ +static void build_zonelists_in_node_order(pg_data_t *pgdat, int *node_order, + unsigned nr_nodes) +{ + struct zoneref *zonerefs; + int i; + + zonerefs = pgdat->node_zonelists[ZONELIST_FALLBACK]._zonerefs; + + for (i = 0; i < nr_nodes; i++) { + int nr_zones; + + pg_data_t *node = NODE_DATA(node_order[i]); + + nr_zones = build_zonerefs_node(node, zonerefs); + zonerefs += nr_zones; + } + zonerefs->zone = NULL; + zonerefs->zone_idx = 0; +} + +/* + * Build gfp_thisnode zonelists + */ +static void build_thisnode_zonelists(pg_data_t *pgdat) +{ + struct zoneref *zonerefs; + int nr_zones; + + zonerefs = pgdat->node_zonelists[ZONELIST_NOFALLBACK]._zonerefs; + nr_zones = build_zonerefs_node(pgdat, zonerefs); + zonerefs += nr_zones; + zonerefs->zone = NULL; + zonerefs->zone_idx = 0; +} + +/* + * Build zonelists ordered by zone and nodes within zones. + * This results in conserving DMA zone[s] until all Normal memory is + * exhausted, but results in overflowing to remote node while memory + * may still exist in local DMA zone. + */ + +static void build_zonelists(pg_data_t *pgdat) +{ + static int node_order[MAX_NUMNODES]; + int node, load, nr_nodes = 0; + nodemask_t used_mask; + int local_node, prev_node; + + /* NUMA-aware ordering of nodes */ + local_node = pgdat->node_id; + load = nr_online_nodes; + prev_node = local_node; + nodes_clear(used_mask); + + memset(node_order, 0, sizeof(node_order)); + while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { + /* + * We don't want to pressure a particular node. + * So adding penalty to the first node in same + * distance group to make it round-robin. + */ + if (node_distance(local_node, node) != + node_distance(local_node, prev_node)) + node_load[node] = load; + + node_order[nr_nodes++] = node; + prev_node = node; + load--; + } + + build_zonelists_in_node_order(pgdat, node_order, nr_nodes); + build_thisnode_zonelists(pgdat); +} + +#ifdef CONFIG_HAVE_MEMORYLESS_NODES +/* + * Return node id of node used for "local" allocations. + * I.e., first node id of first zone in arg node's generic zonelist. + * Used for initializing percpu 'numa_mem', which is used primarily + * for kernel allocations, so use GFP_KERNEL flags to locate zonelist. + */ +int local_memory_node(int node) +{ + struct zoneref *z; + + z = first_zones_zonelist(node_zonelist(node, GFP_KERNEL), + gfp_zone(GFP_KERNEL), + NULL); + return zone_to_nid(z->zone); +} +#endif + +static void setup_min_unmapped_ratio(void); +static void setup_min_slab_ratio(void); +#else /* CONFIG_NUMA */ + +static void build_zonelists(pg_data_t *pgdat) +{ + int node, local_node; + struct zoneref *zonerefs; + int nr_zones; + + local_node = pgdat->node_id; + + zonerefs = pgdat->node_zonelists[ZONELIST_FALLBACK]._zonerefs; + nr_zones = build_zonerefs_node(pgdat, zonerefs); + zonerefs += nr_zones; + + /* + * Now we build the zonelist so that it contains the zones + * of all the other nodes. + * We don't want to pressure a particular node, so when + * building the zones for node N, we make sure that the + * zones coming right after the local ones are those from + * node N+1 (modulo N) + */ + for (node = local_node + 1; node < MAX_NUMNODES; node++) { + if (!node_online(node)) + continue; + nr_zones = build_zonerefs_node(NODE_DATA(node), zonerefs); + zonerefs += nr_zones; + } + for (node = 0; node < local_node; node++) { + if (!node_online(node)) + continue; + nr_zones = build_zonerefs_node(NODE_DATA(node), zonerefs); + zonerefs += nr_zones; + } + + zonerefs->zone = NULL; + zonerefs->zone_idx = 0; +} + +#endif /* CONFIG_NUMA */ + +/* + * Boot pageset table. One per cpu which is going to be used for all + * zones and all nodes. The parameters will be set in such a way + * that an item put on a list will immediately be handed over to + * the buddy list. This is safe since pageset manipulation is done + * with interrupts disabled. + * + * The boot_pagesets must be kept even after bootup is complete for + * unused processors and/or zones. They do play a role for bootstrapping + * hotplugged processors. + * + * zoneinfo_show() and maybe other functions do + * not check if the processor is online before following the pageset pointer. + * Other parts of the kernel may not check if the zone is available. + */ +static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch); +static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset); +static DEFINE_PER_CPU(struct per_cpu_nodestat, boot_nodestats); + +static void __build_all_zonelists(void *data) +{ + int nid; + int __maybe_unused cpu; + pg_data_t *self = data; + static DEFINE_SPINLOCK(lock); + + spin_lock(&lock); + +#ifdef CONFIG_NUMA + memset(node_load, 0, sizeof(node_load)); +#endif + + /* + * This node is hotadded and no memory is yet present. So just + * building zonelists is fine - no need to touch other nodes. + */ + if (self && !node_online(self->node_id)) { + build_zonelists(self); + } else { + for_each_online_node(nid) { + pg_data_t *pgdat = NODE_DATA(nid); + + build_zonelists(pgdat); + } + +#ifdef CONFIG_HAVE_MEMORYLESS_NODES + /* + * We now know the "local memory node" for each node-- + * i.e., the node of the first zone in the generic zonelist. + * Set up numa_mem percpu variable for on-line cpus. During + * boot, only the boot cpu should be on-line; we'll init the + * secondary cpus' numa_mem as they come on-line. During + * node/memory hotplug, we'll fixup all on-line cpus. + */ + for_each_online_cpu(cpu) + set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu))); +#endif + } + + spin_unlock(&lock); +} + +static noinline void __init +build_all_zonelists_init(void) +{ + int cpu; + + __build_all_zonelists(NULL); + + /* + * Initialize the boot_pagesets that are going to be used + * for bootstrapping processors. The real pagesets for + * each zone will be allocated later when the per cpu + * allocator is available. + * + * boot_pagesets are used also for bootstrapping offline + * cpus if the system is already booted because the pagesets + * are needed to initialize allocators on a specific cpu too. + * F.e. the percpu allocator needs the page allocator which + * needs the percpu allocator in order to allocate its pagesets + * (a chicken-egg dilemma). + */ + for_each_possible_cpu(cpu) + setup_pageset(&per_cpu(boot_pageset, cpu), 0); + + mminit_verify_zonelist(); + cpuset_init_current_mems_allowed(); +} + +/* + * unless system_state == SYSTEM_BOOTING. + * + * __ref due to call of __init annotated helper build_all_zonelists_init + * [protected by SYSTEM_BOOTING]. + */ +void __ref build_all_zonelists(pg_data_t *pgdat) +{ + if (system_state == SYSTEM_BOOTING) { + build_all_zonelists_init(); + } else { + __build_all_zonelists(pgdat); + /* cpuset refresh routine should be here */ + } + vm_total_pages = nr_free_pagecache_pages(); + /* + * Disable grouping by mobility if the number of pages in the + * system is too low to allow the mechanism to work. It would be + * more accurate, but expensive to check per-zone. This check is + * made on memory-hotadd so a system can start with mobility + * disabled and enable it later + */ + if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES)) + page_group_by_mobility_disabled = 1; + else + page_group_by_mobility_disabled = 0; + + pr_info("Built %i zonelists, mobility grouping %s. Total pages: %ld\n", + nr_online_nodes, + page_group_by_mobility_disabled ? "off" : "on", + vm_total_pages); +#ifdef CONFIG_NUMA + pr_info("Policy zone: %s\n", zone_names[policy_zone]); +#endif +} + +/* + * Initially all pages are reserved - free ones are freed + * up by free_all_bootmem() once the early boot process is + * done. Non-atomic initialization, single-pass. + */ +void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, + unsigned long start_pfn, enum meminit_context context, + struct vmem_altmap *altmap) +{ + unsigned long end_pfn = start_pfn + size; + pg_data_t *pgdat = NODE_DATA(nid); + unsigned long pfn; + unsigned long nr_initialised = 0; + struct page *page; +#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP + struct memblock_region *r = NULL, *tmp; +#endif + + if (highest_memmap_pfn < end_pfn - 1) + highest_memmap_pfn = end_pfn - 1; + + /* + * Honor reservation requested by the driver for this ZONE_DEVICE + * memory + */ + if (altmap && start_pfn == altmap->base_pfn) + start_pfn += altmap->reserve; + + for (pfn = start_pfn; pfn < end_pfn; pfn++) { + /* + * There can be holes in boot-time mem_map[]s handed to this + * function. They do not exist on hotplugged memory. + */ + if (context != MEMINIT_EARLY) + goto not_early; + + if (!early_pfn_valid(pfn)) + continue; + if (!early_pfn_in_nid(pfn, nid)) + continue; + if (!update_defer_init(pgdat, pfn, end_pfn, &nr_initialised)) + break; + +#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP + /* + * Check given memblock attribute by firmware which can affect + * kernel memory layout. If zone==ZONE_MOVABLE but memory is + * mirrored, it's an overlapped memmap init. skip it. + */ + if (mirrored_kernelcore && zone == ZONE_MOVABLE) { + if (!r || pfn >= memblock_region_memory_end_pfn(r)) { + for_each_memblock(memory, tmp) + if (pfn < memblock_region_memory_end_pfn(tmp)) + break; + r = tmp; + } + if (pfn >= memblock_region_memory_base_pfn(r) && + memblock_is_mirror(r)) { + /* already initialized as NORMAL */ + pfn = memblock_region_memory_end_pfn(r); + continue; + } + } +#endif + +not_early: + page = pfn_to_page(pfn); + __init_single_page(page, pfn, zone, nid); + if (context == MEMINIT_HOTPLUG) + SetPageReserved(page); + + /* + * Mark the block movable so that blocks are reserved for + * movable at startup. This will force kernel allocations + * to reserve their blocks rather than leaking throughout + * the address space during boot when many long-lived + * kernel allocations are made. + * + * bitmap is created for zone's valid pfn range. but memmap + * can be created for invalid pages (for alignment) + * check here not to call set_pageblock_migratetype() against + * pfn out of zone. + * + * Please note that MEMINIT_HOTPLUG path doesn't clear memmap + * because this is done early in sparse_add_one_section + */ + if (!(pfn & (pageblock_nr_pages - 1))) { + set_pageblock_migratetype(page, MIGRATE_MOVABLE); + cond_resched(); + } + } +} + +static void __meminit zone_init_free_lists(struct zone *zone) +{ + unsigned int order, t; + for_each_migratetype_order(order, t) { + INIT_LIST_HEAD(&zone->free_area[order].free_list[t]); + zone->free_area[order].nr_free = 0; + } +} + +#ifndef __HAVE_ARCH_MEMMAP_INIT +#define memmap_init(size, nid, zone, start_pfn) \ + memmap_init_zone((size), (nid), (zone), (start_pfn), \ + MEMINIT_EARLY, NULL) +#endif + +static int zone_batchsize(struct zone *zone) +{ +#ifdef CONFIG_MMU + int batch; + + /* + * The per-cpu-pages pools are set to around 1000th of the + * size of the zone. + */ + batch = zone->managed_pages / 1024; + /* But no more than a meg. */ + if (batch * PAGE_SIZE > 1024 * 1024) + batch = (1024 * 1024) / PAGE_SIZE; + batch /= 4; /* We effectively *= 4 below */ + if (batch < 1) + batch = 1; + + /* + * Clamp the batch to a 2^n - 1 value. Having a power + * of 2 value was found to be more likely to have + * suboptimal cache aliasing properties in some cases. + * + * For example if 2 tasks are alternately allocating + * batches of pages, one task can end up with a lot + * of pages of one half of the possible page colors + * and the other with pages of the other colors. + */ + batch = rounddown_pow_of_two(batch + batch/2) - 1; + + return batch; + +#else + /* The deferral and batching of frees should be suppressed under NOMMU + * conditions. + * + * The problem is that NOMMU needs to be able to allocate large chunks + * of contiguous memory as there's no hardware page translation to + * assemble apparent contiguous memory from discontiguous pages. + * + * Queueing large contiguous runs of pages for batching, however, + * causes the pages to actually be freed in smaller chunks. As there + * can be a significant delay between the individual batches being + * recycled, this leads to the once large chunks of space being + * fragmented and becoming unavailable for high-order allocations. + */ + return 0; +#endif +} + +/* + * pcp->high and pcp->batch values are related and dependent on one another: + * ->batch must never be higher then ->high. + * The following function updates them in a safe manner without read side + * locking. + * + * Any new users of pcp->batch and pcp->high should ensure they can cope with + * those fields changing asynchronously (acording the the above rule). + * + * mutex_is_locked(&pcp_batch_high_lock) required when calling this function + * outside of boot time (or some other assurance that no concurrent updaters + * exist). + */ +static void pageset_update(struct per_cpu_pages *pcp, unsigned long high, + unsigned long batch) +{ + /* start with a fail safe value for batch */ + pcp->batch = 1; + smp_wmb(); + + /* Update high, then batch, in order */ + pcp->high = high; + smp_wmb(); + + pcp->batch = batch; +} + +/* a companion to pageset_set_high() */ +static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch) +{ + pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch)); +} + +static void pageset_init(struct per_cpu_pageset *p) +{ + struct per_cpu_pages *pcp; + int migratetype; + + memset(p, 0, sizeof(*p)); + + pcp = &p->pcp; + pcp->count = 0; + for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++) + INIT_LIST_HEAD(&pcp->lists[migratetype]); +} + +static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch) +{ + pageset_init(p); + pageset_set_batch(p, batch); +} + +/* + * pageset_set_high() sets the high water mark for hot per_cpu_pagelist + * to the value high for the pageset p. + */ +static void pageset_set_high(struct per_cpu_pageset *p, + unsigned long high) +{ + unsigned long batch = max(1UL, high / 4); + if ((high / 4) > (PAGE_SHIFT * 8)) + batch = PAGE_SHIFT * 8; + + pageset_update(&p->pcp, high, batch); +} + +static void pageset_set_high_and_batch(struct zone *zone, + struct per_cpu_pageset *pcp) +{ + if (percpu_pagelist_fraction) + pageset_set_high(pcp, + (zone->managed_pages / + percpu_pagelist_fraction)); + else + pageset_set_batch(pcp, zone_batchsize(zone)); +} + +static void __meminit zone_pageset_init(struct zone *zone, int cpu) +{ + struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu); + + pageset_init(pcp); + pageset_set_high_and_batch(zone, pcp); +} + +void __meminit setup_zone_pageset(struct zone *zone) +{ + int cpu; + zone->pageset = alloc_percpu(struct per_cpu_pageset); + for_each_possible_cpu(cpu) + zone_pageset_init(zone, cpu); +} + +/* + * Allocate per cpu pagesets and initialize them. + * Before this call only boot pagesets were available. + */ +void __init setup_per_cpu_pageset(void) +{ + struct pglist_data *pgdat; + struct zone *zone; + + for_each_populated_zone(zone) + setup_zone_pageset(zone); + + for_each_online_pgdat(pgdat) + pgdat->per_cpu_nodestats = + alloc_percpu(struct per_cpu_nodestat); +} + +static __meminit void zone_pcp_init(struct zone *zone) +{ + /* + * per cpu subsystem is not up at this point. The following code + * relies on the ability of the linker to provide the + * offset of a (static) per cpu variable into the per cpu area. + */ + zone->pageset = &boot_pageset; + + if (populated_zone(zone)) + printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n", + zone->name, zone->present_pages, + zone_batchsize(zone)); +} + +void __meminit init_currently_empty_zone(struct zone *zone, + unsigned long zone_start_pfn, + unsigned long size) +{ + struct pglist_data *pgdat = zone->zone_pgdat; + int zone_idx = zone_idx(zone) + 1; + + if (zone_idx > pgdat->nr_zones) + pgdat->nr_zones = zone_idx; + + zone->zone_start_pfn = zone_start_pfn; + + mminit_dprintk(MMINIT_TRACE, "memmap_init", + "Initialising map node %d zone %lu pfns %lu -> %lu\n", + pgdat->node_id, + (unsigned long)zone_idx(zone), + zone_start_pfn, (zone_start_pfn + size)); + + zone_init_free_lists(zone); + zone->initialized = 1; +} + +#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP +#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID + +/* + * Required by SPARSEMEM. Given a PFN, return what node the PFN is on. + */ +int __meminit __early_pfn_to_nid(unsigned long pfn, + struct mminit_pfnnid_cache *state) +{ + unsigned long start_pfn, end_pfn; + int nid; + + if (state->last_start <= pfn && pfn < state->last_end) + return state->last_nid; + + nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn); + if (nid != -1) { + state->last_start = start_pfn; + state->last_end = end_pfn; + state->last_nid = nid; + } + + return nid; +} +#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */ + +/** + * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range + * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed. + * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid + * + * If an architecture guarantees that all ranges registered contain no holes + * and may be freed, this this function may be used instead of calling + * memblock_free_early_nid() manually. + */ +void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn) +{ + unsigned long start_pfn, end_pfn; + int i, this_nid; + + for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) { + start_pfn = min(start_pfn, max_low_pfn); + end_pfn = min(end_pfn, max_low_pfn); + + if (start_pfn < end_pfn) + memblock_free_early_nid(PFN_PHYS(start_pfn), + (end_pfn - start_pfn) << PAGE_SHIFT, + this_nid); + } +} + +/** + * sparse_memory_present_with_active_regions - Call memory_present for each active range + * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used. + * + * If an architecture guarantees that all ranges registered contain no holes and may + * be freed, this function may be used instead of calling memory_present() manually. + */ +void __init sparse_memory_present_with_active_regions(int nid) +{ + unsigned long start_pfn, end_pfn; + int i, this_nid; + + for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) + memory_present(this_nid, start_pfn, end_pfn); +} + +/** + * get_pfn_range_for_nid - Return the start and end page frames for a node + * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned. + * @start_pfn: Passed by reference. On return, it will have the node start_pfn. + * @end_pfn: Passed by reference. On return, it will have the node end_pfn. + * + * It returns the start and end page frame of a node based on information + * provided by memblock_set_node(). If called for a node + * with no available memory, a warning is printed and the start and end + * PFNs will be 0. + */ +void __meminit get_pfn_range_for_nid(unsigned int nid, + unsigned long *start_pfn, unsigned long *end_pfn) +{ + unsigned long this_start_pfn, this_end_pfn; + int i; + + *start_pfn = -1UL; + *end_pfn = 0; + + for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) { + *start_pfn = min(*start_pfn, this_start_pfn); + *end_pfn = max(*end_pfn, this_end_pfn); + } + + if (*start_pfn == -1UL) + *start_pfn = 0; +} + +/* + * This finds a zone that can be used for ZONE_MOVABLE pages. The + * assumption is made that zones within a node are ordered in monotonic + * increasing memory addresses so that the "highest" populated zone is used + */ +static void __init find_usable_zone_for_movable(void) +{ + int zone_index; + for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) { + if (zone_index == ZONE_MOVABLE) + continue; + + if (arch_zone_highest_possible_pfn[zone_index] > + arch_zone_lowest_possible_pfn[zone_index]) + break; + } + + VM_BUG_ON(zone_index == -1); + movable_zone = zone_index; +} + +/* + * The zone ranges provided by the architecture do not include ZONE_MOVABLE + * because it is sized independent of architecture. Unlike the other zones, + * the starting point for ZONE_MOVABLE is not fixed. It may be different + * in each node depending on the size of each node and how evenly kernelcore + * is distributed. This helper function adjusts the zone ranges + * provided by the architecture for a given node by using the end of the + * highest usable zone for ZONE_MOVABLE. This preserves the assumption that + * zones within a node are in order of monotonic increases memory addresses + */ +static void __meminit adjust_zone_range_for_zone_movable(int nid, + unsigned long zone_type, + unsigned long node_start_pfn, + unsigned long node_end_pfn, + unsigned long *zone_start_pfn, + unsigned long *zone_end_pfn) +{ + /* Only adjust if ZONE_MOVABLE is on this node */ + if (zone_movable_pfn[nid]) { + /* Size ZONE_MOVABLE */ + if (zone_type == ZONE_MOVABLE) { + *zone_start_pfn = zone_movable_pfn[nid]; + *zone_end_pfn = min(node_end_pfn, + arch_zone_highest_possible_pfn[movable_zone]); + + /* Adjust for ZONE_MOVABLE starting within this range */ + } else if (!mirrored_kernelcore && + *zone_start_pfn < zone_movable_pfn[nid] && + *zone_end_pfn > zone_movable_pfn[nid]) { + *zone_end_pfn = zone_movable_pfn[nid]; + + /* Check if this whole range is within ZONE_MOVABLE */ + } else if (*zone_start_pfn >= zone_movable_pfn[nid]) + *zone_start_pfn = *zone_end_pfn; + } +} + +/* + * Return the number of pages a zone spans in a node, including holes + * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node() + */ +static unsigned long __meminit zone_spanned_pages_in_node(int nid, + unsigned long zone_type, + unsigned long node_start_pfn, + unsigned long node_end_pfn, + unsigned long *zone_start_pfn, + unsigned long *zone_end_pfn, + unsigned long *ignored) +{ + unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type]; + unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type]; + /* When hotadd a new node from cpu_up(), the node should be empty */ + if (!node_start_pfn && !node_end_pfn) + return 0; + + /* Get the start and end of the zone */ + *zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high); + *zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high); + adjust_zone_range_for_zone_movable(nid, zone_type, + node_start_pfn, node_end_pfn, + zone_start_pfn, zone_end_pfn); + + /* Check that this node has pages within the zone's required range */ + if (*zone_end_pfn < node_start_pfn || *zone_start_pfn > node_end_pfn) + return 0; + + /* Move the zone boundaries inside the node if necessary */ + *zone_end_pfn = min(*zone_end_pfn, node_end_pfn); + *zone_start_pfn = max(*zone_start_pfn, node_start_pfn); + + /* Return the spanned pages */ + return *zone_end_pfn - *zone_start_pfn; +} + +/* + * Return the number of holes in a range on a node. If nid is MAX_NUMNODES, + * then all holes in the requested range will be accounted for. + */ +unsigned long __meminit __absent_pages_in_range(int nid, + unsigned long range_start_pfn, + unsigned long range_end_pfn) +{ + unsigned long nr_absent = range_end_pfn - range_start_pfn; + unsigned long start_pfn, end_pfn; + int i; + + for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) { + start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn); + end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn); + nr_absent -= end_pfn - start_pfn; + } + return nr_absent; +} + +/** + * absent_pages_in_range - Return number of page frames in holes within a range + * @start_pfn: The start PFN to start searching for holes + * @end_pfn: The end PFN to stop searching for holes + * + * It returns the number of pages frames in memory holes within a range. + */ +unsigned long __init absent_pages_in_range(unsigned long start_pfn, + unsigned long end_pfn) +{ + return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn); +} + +/* Return the number of page frames in holes in a zone on a node */ +static unsigned long __meminit zone_absent_pages_in_node(int nid, + unsigned long zone_type, + unsigned long node_start_pfn, + unsigned long node_end_pfn, + unsigned long *ignored) +{ + unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type]; + unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type]; + unsigned long zone_start_pfn, zone_end_pfn; + unsigned long nr_absent; + + /* When hotadd a new node from cpu_up(), the node should be empty */ + if (!node_start_pfn && !node_end_pfn) + return 0; + + zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high); + zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high); + + adjust_zone_range_for_zone_movable(nid, zone_type, + node_start_pfn, node_end_pfn, + &zone_start_pfn, &zone_end_pfn); + nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn); + + /* + * ZONE_MOVABLE handling. + * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages + * and vice versa. + */ + if (mirrored_kernelcore && zone_movable_pfn[nid]) { + unsigned long start_pfn, end_pfn; + struct memblock_region *r; + + for_each_memblock(memory, r) { + start_pfn = clamp(memblock_region_memory_base_pfn(r), + zone_start_pfn, zone_end_pfn); + end_pfn = clamp(memblock_region_memory_end_pfn(r), + zone_start_pfn, zone_end_pfn); + + if (zone_type == ZONE_MOVABLE && + memblock_is_mirror(r)) + nr_absent += end_pfn - start_pfn; + + if (zone_type == ZONE_NORMAL && + !memblock_is_mirror(r)) + nr_absent += end_pfn - start_pfn; + } + } + + return nr_absent; +} + +#else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ +static inline unsigned long __meminit zone_spanned_pages_in_node(int nid, + unsigned long zone_type, + unsigned long node_start_pfn, + unsigned long node_end_pfn, + unsigned long *zone_start_pfn, + unsigned long *zone_end_pfn, + unsigned long *zones_size) +{ + unsigned int zone; + + *zone_start_pfn = node_start_pfn; + for (zone = 0; zone < zone_type; zone++) + *zone_start_pfn += zones_size[zone]; + + *zone_end_pfn = *zone_start_pfn + zones_size[zone_type]; + + return zones_size[zone_type]; +} + +static inline unsigned long __meminit zone_absent_pages_in_node(int nid, + unsigned long zone_type, + unsigned long node_start_pfn, + unsigned long node_end_pfn, + unsigned long *zholes_size) +{ + if (!zholes_size) + return 0; + + return zholes_size[zone_type]; +} + +#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ + +static void __meminit calculate_node_totalpages(struct pglist_data *pgdat, + unsigned long node_start_pfn, + unsigned long node_end_pfn, + unsigned long *zones_size, + unsigned long *zholes_size) +{ + unsigned long realtotalpages = 0, totalpages = 0; + enum zone_type i; + + for (i = 0; i < MAX_NR_ZONES; i++) { + struct zone *zone = pgdat->node_zones + i; + unsigned long zone_start_pfn, zone_end_pfn; + unsigned long size, real_size; + + size = zone_spanned_pages_in_node(pgdat->node_id, i, + node_start_pfn, + node_end_pfn, + &zone_start_pfn, + &zone_end_pfn, + zones_size); + real_size = size - zone_absent_pages_in_node(pgdat->node_id, i, + node_start_pfn, node_end_pfn, + zholes_size); + if (size) + zone->zone_start_pfn = zone_start_pfn; + else + zone->zone_start_pfn = 0; + zone->spanned_pages = size; + zone->present_pages = real_size; + + totalpages += size; + realtotalpages += real_size; + } + + pgdat->node_spanned_pages = totalpages; + pgdat->node_present_pages = realtotalpages; + printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, + realtotalpages); +} + +#ifndef CONFIG_SPARSEMEM +/* + * Calculate the size of the zone->blockflags rounded to an unsigned long + * Start by making sure zonesize is a multiple of pageblock_order by rounding + * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally + * round what is now in bits to nearest long in bits, then return it in + * bytes. + */ +static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize) +{ + unsigned long usemapsize; + + zonesize += zone_start_pfn & (pageblock_nr_pages-1); + usemapsize = roundup(zonesize, pageblock_nr_pages); + usemapsize = usemapsize >> pageblock_order; + usemapsize *= NR_PAGEBLOCK_BITS; + usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long)); + + return usemapsize / 8; +} + +static void __ref setup_usemap(struct pglist_data *pgdat, + struct zone *zone, + unsigned long zone_start_pfn, + unsigned long zonesize) +{ + unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize); + zone->pageblock_flags = NULL; + if (usemapsize) + zone->pageblock_flags = + memblock_virt_alloc_node_nopanic(usemapsize, + pgdat->node_id); +} +#else +static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone, + unsigned long zone_start_pfn, unsigned long zonesize) {} +#endif /* CONFIG_SPARSEMEM */ + +#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE + +/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */ +void __init set_pageblock_order(void) +{ + unsigned int order; + + /* Check that pageblock_nr_pages has not already been setup */ + if (pageblock_order) + return; + + if (HPAGE_SHIFT > PAGE_SHIFT) + order = HUGETLB_PAGE_ORDER; + else + order = MAX_ORDER - 1; + + /* + * Assume the largest contiguous order of interest is a huge page. + * This value may be variable depending on boot parameters on IA64 and + * powerpc. + */ + pageblock_order = order; +} +#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ + +/* + * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order() + * is unused as pageblock_order is set at compile-time. See + * include/linux/pageblock-flags.h for the values of pageblock_order based on + * the kernel config + */ +void __init set_pageblock_order(void) +{ +} + +#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ + +static unsigned long __init calc_memmap_size(unsigned long spanned_pages, + unsigned long present_pages) +{ + unsigned long pages = spanned_pages; + + /* + * Provide a more accurate estimation if there are holes within + * the zone and SPARSEMEM is in use. If there are holes within the + * zone, each populated memory region may cost us one or two extra + * memmap pages due to alignment because memmap pages for each + * populated regions may not be naturally aligned on page boundary. + * So the (present_pages >> 4) heuristic is a tradeoff for that. + */ + if (spanned_pages > present_pages + (present_pages >> 4) && + IS_ENABLED(CONFIG_SPARSEMEM)) + pages = present_pages; + + return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT; +} + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static void pgdat_init_split_queue(struct pglist_data *pgdat) +{ + spin_lock_init(&pgdat->split_queue_lock); + INIT_LIST_HEAD(&pgdat->split_queue); + pgdat->split_queue_len = 0; +} +#else +static void pgdat_init_split_queue(struct pglist_data *pgdat) {} +#endif + +#ifdef CONFIG_COMPACTION +static void pgdat_init_kcompactd(struct pglist_data *pgdat) +{ + init_waitqueue_head(&pgdat->kcompactd_wait); +} +#else +static void pgdat_init_kcompactd(struct pglist_data *pgdat) {} +#endif + +static void __meminit pgdat_init_internals(struct pglist_data *pgdat) +{ + pgdat_resize_init(pgdat); + + pgdat_init_split_queue(pgdat); + pgdat_init_kcompactd(pgdat); + + init_waitqueue_head(&pgdat->kswapd_wait); + init_waitqueue_head(&pgdat->pfmemalloc_wait); + + pgdat_page_ext_init(pgdat); + spin_lock_init(&pgdat->lru_lock); + lruvec_init(node_lruvec(pgdat)); +} + +static void __meminit zone_init_internals(struct zone *zone, enum zone_type idx, int nid, + unsigned long remaining_pages) +{ + zone->managed_pages = remaining_pages; + zone_set_nid(zone, nid); + zone->name = zone_names[idx]; + zone->zone_pgdat = NODE_DATA(nid); + spin_lock_init(&zone->lock); + zone_seqlock_init(zone); + zone_pcp_init(zone); +} + +/* + * Set up the zone data structures + * - init pgdat internals + * - init all zones belonging to this node + * + * NOTE: this function is only called during memory hotplug + */ +#ifdef CONFIG_MEMORY_HOTPLUG +void __ref free_area_init_core_hotplug(int nid) +{ + enum zone_type z; + pg_data_t *pgdat = NODE_DATA(nid); + + pgdat_init_internals(pgdat); + for (z = 0; z < MAX_NR_ZONES; z++) + zone_init_internals(&pgdat->node_zones[z], z, nid, 0); +} +#endif + +/* + * Set up the zone data structures: + * - mark all pages reserved + * - mark all memory queues empty + * - clear the memory bitmaps + * + * NOTE: pgdat should get zeroed by caller. + * NOTE: this function is only called during early init. + */ +static void __init free_area_init_core(struct pglist_data *pgdat) +{ + enum zone_type j; + int nid = pgdat->node_id; + + pgdat_init_internals(pgdat); + pgdat->per_cpu_nodestats = &boot_nodestats; + + for (j = 0; j < MAX_NR_ZONES; j++) { + struct zone *zone = pgdat->node_zones + j; + unsigned long size, freesize, memmap_pages; + unsigned long zone_start_pfn = zone->zone_start_pfn; + + size = zone->spanned_pages; + freesize = zone->present_pages; + + /* + * Adjust freesize so that it accounts for how much memory + * is used by this zone for memmap. This affects the watermark + * and per-cpu initialisations + */ + memmap_pages = calc_memmap_size(size, freesize); + if (!is_highmem_idx(j)) { + if (freesize >= memmap_pages) { + freesize -= memmap_pages; + if (memmap_pages) + printk(KERN_DEBUG + " %s zone: %lu pages used for memmap\n", + zone_names[j], memmap_pages); + } else + pr_warn(" %s zone: %lu pages exceeds freesize %lu\n", + zone_names[j], memmap_pages, freesize); + } + + /* Account for reserved pages */ + if (j == 0 && freesize > dma_reserve) { + freesize -= dma_reserve; + printk(KERN_DEBUG " %s zone: %lu pages reserved\n", + zone_names[0], dma_reserve); + } + + if (!is_highmem_idx(j)) + nr_kernel_pages += freesize; + /* Charge for highmem memmap if there are enough kernel pages */ + else if (nr_kernel_pages > memmap_pages * 2) + nr_kernel_pages -= memmap_pages; + nr_all_pages += freesize; + + /* + * Set an approximate value for lowmem here, it will be adjusted + * when the bootmem allocator frees pages into the buddy system. + * And all highmem pages will be managed by the buddy system. + */ + zone_init_internals(zone, j, nid, freesize); + + if (!size) + continue; + + set_pageblock_order(); + setup_usemap(pgdat, zone, zone_start_pfn, size); + init_currently_empty_zone(zone, zone_start_pfn, size); + memmap_init(size, nid, j, zone_start_pfn); + } +} + +#ifdef CONFIG_FLAT_NODE_MEM_MAP +static void __ref alloc_node_mem_map(struct pglist_data *pgdat) +{ + unsigned long __maybe_unused start = 0; + unsigned long __maybe_unused offset = 0; + + /* Skip empty nodes */ + if (!pgdat->node_spanned_pages) + return; + + start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1); + offset = pgdat->node_start_pfn - start; + /* ia64 gets its own node_mem_map, before this, without bootmem */ + if (!pgdat->node_mem_map) { + unsigned long size, end; + struct page *map; + + /* + * The zone's endpoints aren't required to be MAX_ORDER + * aligned but the node_mem_map endpoints must be in order + * for the buddy allocator to function correctly. + */ + end = pgdat_end_pfn(pgdat); + end = ALIGN(end, MAX_ORDER_NR_PAGES); + size = (end - start) * sizeof(struct page); + map = memblock_virt_alloc_node_nopanic(size, pgdat->node_id); + pgdat->node_mem_map = map + offset; + } + pr_debug("%s: node %d, pgdat %08lx, node_mem_map %08lx\n", + __func__, pgdat->node_id, (unsigned long)pgdat, + (unsigned long)pgdat->node_mem_map); +#ifndef CONFIG_NEED_MULTIPLE_NODES + /* + * With no DISCONTIG, the global mem_map is just set as node 0's + */ + if (pgdat == NODE_DATA(0)) { + mem_map = NODE_DATA(0)->node_mem_map; +#if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM) + if (page_to_pfn(mem_map) != pgdat->node_start_pfn) + mem_map -= offset; +#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ + } +#endif +} +#else +static void __ref alloc_node_mem_map(struct pglist_data *pgdat) { } +#endif /* CONFIG_FLAT_NODE_MEM_MAP */ + +#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT +static inline void pgdat_set_deferred_range(pg_data_t *pgdat) +{ + /* + * We start only with one section of pages, more pages are added as + * needed until the rest of deferred pages are initialized. + */ + pgdat->static_init_pgcnt = min_t(unsigned long, PAGES_PER_SECTION, + pgdat->node_spanned_pages); + pgdat->first_deferred_pfn = ULONG_MAX; +} +#else +static inline void pgdat_set_deferred_range(pg_data_t *pgdat) {} +#endif + +void __init free_area_init_node(int nid, unsigned long *zones_size, + unsigned long node_start_pfn, + unsigned long *zholes_size) +{ + pg_data_t *pgdat = NODE_DATA(nid); + unsigned long start_pfn = 0; + unsigned long end_pfn = 0; + + /* pg_data_t should be reset to zero when it's allocated */ + WARN_ON(pgdat->nr_zones || pgdat->kswapd_classzone_idx); + + pgdat->node_id = nid; + pgdat->node_start_pfn = node_start_pfn; + pgdat->per_cpu_nodestats = NULL; +#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP + get_pfn_range_for_nid(nid, &start_pfn, &end_pfn); + pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid, + (u64)start_pfn << PAGE_SHIFT, + end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0); +#else + start_pfn = node_start_pfn; +#endif + calculate_node_totalpages(pgdat, start_pfn, end_pfn, + zones_size, zholes_size); + + alloc_node_mem_map(pgdat); + pgdat_set_deferred_range(pgdat); + + free_area_init_core(pgdat); +} + +#if defined(CONFIG_HAVE_MEMBLOCK) && !defined(CONFIG_FLAT_NODE_MEM_MAP) + +/* + * Zero all valid struct pages in range [spfn, epfn), return number of struct + * pages zeroed + */ +static u64 zero_pfn_range(unsigned long spfn, unsigned long epfn) +{ + unsigned long pfn; + u64 pgcnt = 0; + + for (pfn = spfn; pfn < epfn; pfn++) { + if (!pfn_valid(ALIGN_DOWN(pfn, pageblock_nr_pages))) { + pfn = ALIGN_DOWN(pfn, pageblock_nr_pages) + + pageblock_nr_pages - 1; + continue; + } + mm_zero_struct_page(pfn_to_page(pfn)); + pgcnt++; + } + + return pgcnt; +} + +/* + * Only struct pages that are backed by physical memory are zeroed and + * initialized by going through __init_single_page(). But, there are some + * struct pages which are reserved in memblock allocator and their fields + * may be accessed (for example page_to_pfn() on some configuration accesses + * flags). We must explicitly zero those struct pages. + * + * This function also addresses a similar issue where struct pages are left + * uninitialized because the physical address range is not covered by + * memblock.memory or memblock.reserved. That could happen when memblock + * layout is manually configured via memmap=, or when the highest physical + * address (max_pfn) does not end on a section boundary. + */ +void __init zero_resv_unavail(void) +{ + phys_addr_t start, end; + u64 i, pgcnt; + phys_addr_t next = 0; + + /* + * Loop through unavailable ranges not covered by memblock.memory. + */ + pgcnt = 0; + for_each_mem_range(i, &memblock.memory, NULL, + NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end, NULL) { + if (next < start) + pgcnt += zero_pfn_range(PFN_DOWN(next), PFN_UP(start)); + next = end; + } + + /* + * Early sections always have a fully populated memmap for the whole + * section - see pfn_valid(). If the last section has holes at the + * end and that section is marked "online", the memmap will be + * considered initialized. Make sure that memmap has a well defined + * state. + */ + pgcnt += zero_pfn_range(PFN_DOWN(next), + round_up(max_pfn, PAGES_PER_SECTION)); + + /* + * Struct pages that do not have backing memory. This could be because + * firmware is using some of this memory, or for some other reasons. + */ + if (pgcnt) + pr_info("Zeroed struct page in unavailable ranges: %lld pages", pgcnt); +} +#endif /* CONFIG_HAVE_MEMBLOCK && !CONFIG_FLAT_NODE_MEM_MAP */ + +#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP + +#if MAX_NUMNODES > 1 +/* + * Figure out the number of possible node ids. + */ +void __init setup_nr_node_ids(void) +{ + unsigned int highest; + + highest = find_last_bit(node_possible_map.bits, MAX_NUMNODES); + nr_node_ids = highest + 1; +} +#endif + +/** + * node_map_pfn_alignment - determine the maximum internode alignment + * + * This function should be called after node map is populated and sorted. + * It calculates the maximum power of two alignment which can distinguish + * all the nodes. + * + * For example, if all nodes are 1GiB and aligned to 1GiB, the return value + * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the + * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is + * shifted, 1GiB is enough and this function will indicate so. + * + * This is used to test whether pfn -> nid mapping of the chosen memory + * model has fine enough granularity to avoid incorrect mapping for the + * populated node map. + * + * Returns the determined alignment in pfn's. 0 if there is no alignment + * requirement (single node). + */ +unsigned long __init node_map_pfn_alignment(void) +{ + unsigned long accl_mask = 0, last_end = 0; + unsigned long start, end, mask; + int last_nid = -1; + int i, nid; + + for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) { + if (!start || last_nid < 0 || last_nid == nid) { + last_nid = nid; + last_end = end; + continue; + } + + /* + * Start with a mask granular enough to pin-point to the + * start pfn and tick off bits one-by-one until it becomes + * too coarse to separate the current node from the last. + */ + mask = ~((1 << __ffs(start)) - 1); + while (mask && last_end <= (start & (mask << 1))) + mask <<= 1; + + /* accumulate all internode masks */ + accl_mask |= mask; + } + + /* convert mask to number of pages */ + return ~accl_mask + 1; +} + +/* Find the lowest pfn for a node */ +static unsigned long __init find_min_pfn_for_node(int nid) +{ + unsigned long min_pfn = ULONG_MAX; + unsigned long start_pfn; + int i; + + for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL) + min_pfn = min(min_pfn, start_pfn); + + if (min_pfn == ULONG_MAX) { + pr_warn("Could not find start_pfn for node %d\n", nid); + return 0; + } + + return min_pfn; +} + +/** + * find_min_pfn_with_active_regions - Find the minimum PFN registered + * + * It returns the minimum PFN based on information provided via + * memblock_set_node(). + */ +unsigned long __init find_min_pfn_with_active_regions(void) +{ + return find_min_pfn_for_node(MAX_NUMNODES); +} + +/* + * early_calculate_totalpages() + * Sum pages in active regions for movable zone. + * Populate N_MEMORY for calculating usable_nodes. + */ +static unsigned long __init early_calculate_totalpages(void) +{ + unsigned long totalpages = 0; + unsigned long start_pfn, end_pfn; + int i, nid; + + for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) { + unsigned long pages = end_pfn - start_pfn; + + totalpages += pages; + if (pages) + node_set_state(nid, N_MEMORY); + } + return totalpages; +} + +/* + * Find the PFN the Movable zone begins in each node. Kernel memory + * is spread evenly between nodes as long as the nodes have enough + * memory. When they don't, some nodes will have more kernelcore than + * others + */ +static void __init find_zone_movable_pfns_for_nodes(void) +{ + int i, nid; + unsigned long usable_startpfn; + unsigned long kernelcore_node, kernelcore_remaining; + /* save the state before borrow the nodemask */ + nodemask_t saved_node_state = node_states[N_MEMORY]; + unsigned long totalpages = early_calculate_totalpages(); + int usable_nodes = nodes_weight(node_states[N_MEMORY]); + struct memblock_region *r; + + /* Need to find movable_zone earlier when movable_node is specified. */ + find_usable_zone_for_movable(); + + /* + * If movable_node is specified, ignore kernelcore and movablecore + * options. + */ + if (movable_node_is_enabled()) { + for_each_memblock(memory, r) { + if (!memblock_is_hotpluggable(r)) + continue; + + nid = r->nid; + + usable_startpfn = PFN_DOWN(r->base); + zone_movable_pfn[nid] = zone_movable_pfn[nid] ? + min(usable_startpfn, zone_movable_pfn[nid]) : + usable_startpfn; + } + + goto out2; + } + + /* + * If kernelcore=mirror is specified, ignore movablecore option + */ + if (mirrored_kernelcore) { + bool mem_below_4gb_not_mirrored = false; + + for_each_memblock(memory, r) { + if (memblock_is_mirror(r)) + continue; + + nid = r->nid; + + usable_startpfn = memblock_region_memory_base_pfn(r); + + if (usable_startpfn < 0x100000) { + mem_below_4gb_not_mirrored = true; + continue; + } + + zone_movable_pfn[nid] = zone_movable_pfn[nid] ? + min(usable_startpfn, zone_movable_pfn[nid]) : + usable_startpfn; + } + + if (mem_below_4gb_not_mirrored) + pr_warn("This configuration results in unmirrored kernel memory."); + + goto out2; + } + + /* + * If kernelcore=nn% or movablecore=nn% was specified, calculate the + * amount of necessary memory. + */ + if (required_kernelcore_percent) + required_kernelcore = (totalpages * 100 * required_kernelcore_percent) / + 10000UL; + if (required_movablecore_percent) + required_movablecore = (totalpages * 100 * required_movablecore_percent) / + 10000UL; + + /* + * If movablecore= was specified, calculate what size of + * kernelcore that corresponds so that memory usable for + * any allocation type is evenly spread. If both kernelcore + * and movablecore are specified, then the value of kernelcore + * will be used for required_kernelcore if it's greater than + * what movablecore would have allowed. + */ + if (required_movablecore) { + unsigned long corepages; + + /* + * Round-up so that ZONE_MOVABLE is at least as large as what + * was requested by the user + */ + required_movablecore = + roundup(required_movablecore, MAX_ORDER_NR_PAGES); + required_movablecore = min(totalpages, required_movablecore); + corepages = totalpages - required_movablecore; + + required_kernelcore = max(required_kernelcore, corepages); + } + + /* + * If kernelcore was not specified or kernelcore size is larger + * than totalpages, there is no ZONE_MOVABLE. + */ + if (!required_kernelcore || required_kernelcore >= totalpages) + goto out; + + /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */ + usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone]; + +restart: + /* Spread kernelcore memory as evenly as possible throughout nodes */ + kernelcore_node = required_kernelcore / usable_nodes; + for_each_node_state(nid, N_MEMORY) { + unsigned long start_pfn, end_pfn; + + /* + * Recalculate kernelcore_node if the division per node + * now exceeds what is necessary to satisfy the requested + * amount of memory for the kernel + */ + if (required_kernelcore < kernelcore_node) + kernelcore_node = required_kernelcore / usable_nodes; + + /* + * As the map is walked, we track how much memory is usable + * by the kernel using kernelcore_remaining. When it is + * 0, the rest of the node is usable by ZONE_MOVABLE + */ + kernelcore_remaining = kernelcore_node; + + /* Go through each range of PFNs within this node */ + for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) { + unsigned long size_pages; + + start_pfn = max(start_pfn, zone_movable_pfn[nid]); + if (start_pfn >= end_pfn) + continue; + + /* Account for what is only usable for kernelcore */ + if (start_pfn < usable_startpfn) { + unsigned long kernel_pages; + kernel_pages = min(end_pfn, usable_startpfn) + - start_pfn; + + kernelcore_remaining -= min(kernel_pages, + kernelcore_remaining); + required_kernelcore -= min(kernel_pages, + required_kernelcore); + + /* Continue if range is now fully accounted */ + if (end_pfn <= usable_startpfn) { + + /* + * Push zone_movable_pfn to the end so + * that if we have to rebalance + * kernelcore across nodes, we will + * not double account here + */ + zone_movable_pfn[nid] = end_pfn; + continue; + } + start_pfn = usable_startpfn; + } + + /* + * The usable PFN range for ZONE_MOVABLE is from + * start_pfn->end_pfn. Calculate size_pages as the + * number of pages used as kernelcore + */ + size_pages = end_pfn - start_pfn; + if (size_pages > kernelcore_remaining) + size_pages = kernelcore_remaining; + zone_movable_pfn[nid] = start_pfn + size_pages; + + /* + * Some kernelcore has been met, update counts and + * break if the kernelcore for this node has been + * satisfied + */ + required_kernelcore -= min(required_kernelcore, + size_pages); + kernelcore_remaining -= size_pages; + if (!kernelcore_remaining) + break; + } + } + + /* + * If there is still required_kernelcore, we do another pass with one + * less node in the count. This will push zone_movable_pfn[nid] further + * along on the nodes that still have memory until kernelcore is + * satisfied + */ + usable_nodes--; + if (usable_nodes && required_kernelcore > usable_nodes) + goto restart; + +out2: + /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */ + for (nid = 0; nid < MAX_NUMNODES; nid++) { + unsigned long start_pfn, end_pfn; + + zone_movable_pfn[nid] = + roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES); + + get_pfn_range_for_nid(nid, &start_pfn, &end_pfn); + if (zone_movable_pfn[nid] >= end_pfn) + zone_movable_pfn[nid] = 0; + } + +out: + /* restore the node_state */ + node_states[N_MEMORY] = saved_node_state; +} + +/* Any regular or high memory on that node ? */ +static void check_for_memory(pg_data_t *pgdat, int nid) +{ + enum zone_type zone_type; + + if (N_MEMORY == N_NORMAL_MEMORY) + return; + + for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) { + struct zone *zone = &pgdat->node_zones[zone_type]; + if (populated_zone(zone)) { + node_set_state(nid, N_HIGH_MEMORY); + if (N_NORMAL_MEMORY != N_HIGH_MEMORY && + zone_type <= ZONE_NORMAL) + node_set_state(nid, N_NORMAL_MEMORY); + break; + } + } +} + +/** + * free_area_init_nodes - Initialise all pg_data_t and zone data + * @max_zone_pfn: an array of max PFNs for each zone + * + * This will call free_area_init_node() for each active node in the system. + * Using the page ranges provided by memblock_set_node(), the size of each + * zone in each node and their holes is calculated. If the maximum PFN + * between two adjacent zones match, it is assumed that the zone is empty. + * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed + * that arch_max_dma32_pfn has no pages. It is also assumed that a zone + * starts where the previous one ended. For example, ZONE_DMA32 starts + * at arch_max_dma_pfn. + */ +void __init free_area_init_nodes(unsigned long *max_zone_pfn) +{ + unsigned long start_pfn, end_pfn; + int i, nid; + + /* Record where the zone boundaries are */ + memset(arch_zone_lowest_possible_pfn, 0, + sizeof(arch_zone_lowest_possible_pfn)); + memset(arch_zone_highest_possible_pfn, 0, + sizeof(arch_zone_highest_possible_pfn)); + + start_pfn = find_min_pfn_with_active_regions(); + + for (i = 0; i < MAX_NR_ZONES; i++) { + if (i == ZONE_MOVABLE) + continue; + + end_pfn = max(max_zone_pfn[i], start_pfn); + arch_zone_lowest_possible_pfn[i] = start_pfn; + arch_zone_highest_possible_pfn[i] = end_pfn; + + start_pfn = end_pfn; + } + + /* Find the PFNs that ZONE_MOVABLE begins at in each node */ + memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn)); + find_zone_movable_pfns_for_nodes(); + + /* Print out the zone ranges */ + pr_info("Zone ranges:\n"); + for (i = 0; i < MAX_NR_ZONES; i++) { + if (i == ZONE_MOVABLE) + continue; + pr_info(" %-8s ", zone_names[i]); + if (arch_zone_lowest_possible_pfn[i] == + arch_zone_highest_possible_pfn[i]) + pr_cont("empty\n"); + else + pr_cont("[mem %#018Lx-%#018Lx]\n", + (u64)arch_zone_lowest_possible_pfn[i] + << PAGE_SHIFT, + ((u64)arch_zone_highest_possible_pfn[i] + << PAGE_SHIFT) - 1); + } + + /* Print out the PFNs ZONE_MOVABLE begins at in each node */ + pr_info("Movable zone start for each node\n"); + for (i = 0; i < MAX_NUMNODES; i++) { + if (zone_movable_pfn[i]) + pr_info(" Node %d: %#018Lx\n", i, + (u64)zone_movable_pfn[i] << PAGE_SHIFT); + } + + /* Print out the early node map */ + pr_info("Early memory node ranges\n"); + for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) + pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid, + (u64)start_pfn << PAGE_SHIFT, + ((u64)end_pfn << PAGE_SHIFT) - 1); + + /* Initialise every node */ + mminit_verify_pageflags_layout(); + setup_nr_node_ids(); + zero_resv_unavail(); + for_each_online_node(nid) { + pg_data_t *pgdat = NODE_DATA(nid); + free_area_init_node(nid, NULL, + find_min_pfn_for_node(nid), NULL); + + /* Any memory on that node */ + if (pgdat->node_present_pages) + node_set_state(nid, N_MEMORY); + check_for_memory(pgdat, nid); + } +} + +static int __init cmdline_parse_core(char *p, unsigned long *core, + unsigned long *percent) +{ + unsigned long long coremem; + char *endptr; + + if (!p) + return -EINVAL; + + /* Value may be a percentage of total memory, otherwise bytes */ + coremem = simple_strtoull(p, &endptr, 0); + if (*endptr == '%') { + /* Paranoid check for percent values greater than 100 */ + WARN_ON(coremem > 100); + + *percent = coremem; + } else { + coremem = memparse(p, &p); + /* Paranoid check that UL is enough for the coremem value */ + WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX); + + *core = coremem >> PAGE_SHIFT; + *percent = 0UL; + } + return 0; +} + +/* + * kernelcore=size sets the amount of memory for use for allocations that + * cannot be reclaimed or migrated. + */ +static int __init cmdline_parse_kernelcore(char *p) +{ + /* parse kernelcore=mirror */ + if (parse_option_str(p, "mirror")) { + mirrored_kernelcore = true; + return 0; + } + + return cmdline_parse_core(p, &required_kernelcore, + &required_kernelcore_percent); +} + +/* + * movablecore=size sets the amount of memory for use for allocations that + * can be reclaimed or migrated. + */ +static int __init cmdline_parse_movablecore(char *p) +{ + return cmdline_parse_core(p, &required_movablecore, + &required_movablecore_percent); +} + +early_param("kernelcore", cmdline_parse_kernelcore); +early_param("movablecore", cmdline_parse_movablecore); + +#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ + +void adjust_managed_page_count(struct page *page, long count) +{ + spin_lock(&managed_page_count_lock); + page_zone(page)->managed_pages += count; + totalram_pages += count; +#ifdef CONFIG_HIGHMEM + if (PageHighMem(page)) + totalhigh_pages += count; +#endif + spin_unlock(&managed_page_count_lock); +} +EXPORT_SYMBOL(adjust_managed_page_count); + +unsigned long free_reserved_area(void *start, void *end, int poison, char *s) +{ + void *pos; + unsigned long pages = 0; + + start = (void *)PAGE_ALIGN((unsigned long)start); + end = (void *)((unsigned long)end & PAGE_MASK); + for (pos = start; pos < end; pos += PAGE_SIZE, pages++) { + struct page *page = virt_to_page(pos); + void *direct_map_addr; + + /* + * 'direct_map_addr' might be different from 'pos' + * because some architectures' virt_to_page() + * work with aliases. Getting the direct map + * address ensures that we get a _writeable_ + * alias for the memset(). + */ + direct_map_addr = page_address(page); + if ((unsigned int)poison <= 0xFF) + memset(direct_map_addr, poison, PAGE_SIZE); + + free_reserved_page(page); + } + + if (pages && s) + pr_info("Freeing %s memory: %ldK\n", + s, pages << (PAGE_SHIFT - 10)); + + return pages; +} +EXPORT_SYMBOL(free_reserved_area); + +#ifdef CONFIG_HIGHMEM +void free_highmem_page(struct page *page) +{ + __free_reserved_page(page); + totalram_pages++; + page_zone(page)->managed_pages++; + totalhigh_pages++; +} +#endif + + +void __init mem_init_print_info(const char *str) +{ + unsigned long physpages, codesize, datasize, rosize, bss_size; + unsigned long init_code_size, init_data_size; + + physpages = get_num_physpages(); + codesize = _etext - _stext; + datasize = _edata - _sdata; + rosize = __end_rodata - __start_rodata; + bss_size = __bss_stop - __bss_start; + init_data_size = __init_end - __init_begin; + init_code_size = _einittext - _sinittext; + + /* + * Detect special cases and adjust section sizes accordingly: + * 1) .init.* may be embedded into .data sections + * 2) .init.text.* may be out of [__init_begin, __init_end], + * please refer to arch/tile/kernel/vmlinux.lds.S. + * 3) .rodata.* may be embedded into .text or .data sections. + */ +#define adj_init_size(start, end, size, pos, adj) \ + do { \ + if (&start[0] <= &pos[0] && &pos[0] < &end[0] && size > adj) \ + size -= adj; \ + } while (0) + + adj_init_size(__init_begin, __init_end, init_data_size, + _sinittext, init_code_size); + adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size); + adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size); + adj_init_size(_stext, _etext, codesize, __start_rodata, rosize); + adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize); + +#undef adj_init_size + + pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved" +#ifdef CONFIG_HIGHMEM + ", %luK highmem" +#endif + "%s%s)\n", + nr_free_pages() << (PAGE_SHIFT - 10), + physpages << (PAGE_SHIFT - 10), + codesize >> 10, datasize >> 10, rosize >> 10, + (init_data_size + init_code_size) >> 10, bss_size >> 10, + (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT - 10), + totalcma_pages << (PAGE_SHIFT - 10), +#ifdef CONFIG_HIGHMEM + totalhigh_pages << (PAGE_SHIFT - 10), +#endif + str ? ", " : "", str ? str : ""); +} + +/** + * set_dma_reserve - set the specified number of pages reserved in the first zone + * @new_dma_reserve: The number of pages to mark reserved + * + * The per-cpu batchsize and zone watermarks are determined by managed_pages. + * In the DMA zone, a significant percentage may be consumed by kernel image + * and other unfreeable allocations which can skew the watermarks badly. This + * function may optionally be used to account for unfreeable pages in the + * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and + * smaller per-cpu batchsize. + */ +void __init set_dma_reserve(unsigned long new_dma_reserve) +{ + dma_reserve = new_dma_reserve; +} + +void __init free_area_init(unsigned long *zones_size) +{ + zero_resv_unavail(); + free_area_init_node(0, zones_size, + __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); +} + +static int page_alloc_cpu_dead(unsigned int cpu) +{ + + lru_add_drain_cpu(cpu); + drain_pages(cpu); + + /* + * Spill the event counters of the dead processor + * into the current processors event counters. + * This artificially elevates the count of the current + * processor. + */ + vm_events_fold_cpu(cpu); + + /* + * Zero the differential counters of the dead processor + * so that the vm statistics are consistent. + * + * This is only okay since the processor is dead and cannot + * race with what we are doing. + */ + cpu_vm_stats_fold(cpu); + return 0; +} + +void __init page_alloc_init(void) +{ + int ret; + + ret = cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC_DEAD, + "mm/page_alloc:dead", NULL, + page_alloc_cpu_dead); + WARN_ON(ret < 0); +} + +/* + * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio + * or min_free_kbytes changes. + */ +static void calculate_totalreserve_pages(void) +{ + struct pglist_data *pgdat; + unsigned long reserve_pages = 0; + enum zone_type i, j; + + for_each_online_pgdat(pgdat) { + + pgdat->totalreserve_pages = 0; + + for (i = 0; i < MAX_NR_ZONES; i++) { + struct zone *zone = pgdat->node_zones + i; + long max = 0; + + /* Find valid and maximum lowmem_reserve in the zone */ + for (j = i; j < MAX_NR_ZONES; j++) { + if (zone->lowmem_reserve[j] > max) + max = zone->lowmem_reserve[j]; + } + + /* we treat the high watermark as reserved pages. */ + max += high_wmark_pages(zone); + + if (max > zone->managed_pages) + max = zone->managed_pages; + + pgdat->totalreserve_pages += max; + + reserve_pages += max; + } + } + totalreserve_pages = reserve_pages; +} + +/* + * setup_per_zone_lowmem_reserve - called whenever + * sysctl_lowmem_reserve_ratio changes. Ensures that each zone + * has a correct pages reserved value, so an adequate number of + * pages are left in the zone after a successful __alloc_pages(). + */ +static void setup_per_zone_lowmem_reserve(void) +{ + struct pglist_data *pgdat; + enum zone_type j, idx; + + for_each_online_pgdat(pgdat) { + for (j = 0; j < MAX_NR_ZONES; j++) { + struct zone *zone = pgdat->node_zones + j; + unsigned long managed_pages = zone->managed_pages; + + zone->lowmem_reserve[j] = 0; + + idx = j; + while (idx) { + struct zone *lower_zone; + + idx--; + lower_zone = pgdat->node_zones + idx; + + if (sysctl_lowmem_reserve_ratio[idx] < 1) { + sysctl_lowmem_reserve_ratio[idx] = 0; + lower_zone->lowmem_reserve[j] = 0; + } else { + lower_zone->lowmem_reserve[j] = + managed_pages / sysctl_lowmem_reserve_ratio[idx]; + } + managed_pages += lower_zone->managed_pages; + } + } + } + + /* update totalreserve_pages */ + calculate_totalreserve_pages(); +} + +static void __setup_per_zone_wmarks(void) +{ + unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); + unsigned long lowmem_pages = 0; + struct zone *zone; + unsigned long flags; + + /* Calculate total number of !ZONE_HIGHMEM pages */ + for_each_zone(zone) { + if (!is_highmem(zone)) + lowmem_pages += zone->managed_pages; + } + + for_each_zone(zone) { + u64 tmp; + + spin_lock_irqsave(&zone->lock, flags); + tmp = (u64)pages_min * zone->managed_pages; + do_div(tmp, lowmem_pages); + if (is_highmem(zone)) { + /* + * __GFP_HIGH and PF_MEMALLOC allocations usually don't + * need highmem pages, so cap pages_min to a small + * value here. + * + * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN) + * deltas control asynch page reclaim, and so should + * not be capped for highmem. + */ + unsigned long min_pages; + + min_pages = zone->managed_pages / 1024; + min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL); + zone->watermark[WMARK_MIN] = min_pages; + } else { + /* + * If it's a lowmem zone, reserve a number of pages + * proportionate to the zone's size. + */ + zone->watermark[WMARK_MIN] = tmp; + } + + /* + * Set the kswapd watermarks distance according to the + * scale factor in proportion to available memory, but + * ensure a minimum size on small systems. + */ + tmp = max_t(u64, tmp >> 2, + mult_frac(zone->managed_pages, + watermark_scale_factor, 10000)); + + zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + tmp; + zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + tmp * 2; + + spin_unlock_irqrestore(&zone->lock, flags); + } + + /* update totalreserve_pages */ + calculate_totalreserve_pages(); +} + +/** + * setup_per_zone_wmarks - called when min_free_kbytes changes + * or when memory is hot-{added|removed} + * + * Ensures that the watermark[min,low,high] values for each zone are set + * correctly with respect to min_free_kbytes. + */ +void setup_per_zone_wmarks(void) +{ + static DEFINE_SPINLOCK(lock); + + spin_lock(&lock); + __setup_per_zone_wmarks(); + spin_unlock(&lock); +} + +/* + * Initialise min_free_kbytes. + * + * For small machines we want it small (128k min). For large machines + * we want it large (64MB max). But it is not linear, because network + * bandwidth does not increase linearly with machine size. We use + * + * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: + * min_free_kbytes = sqrt(lowmem_kbytes * 16) + * + * which yields + * + * 16MB: 512k + * 32MB: 724k + * 64MB: 1024k + * 128MB: 1448k + * 256MB: 2048k + * 512MB: 2896k + * 1024MB: 4096k + * 2048MB: 5792k + * 4096MB: 8192k + * 8192MB: 11584k + * 16384MB: 16384k + */ +int __meminit init_per_zone_wmark_min(void) +{ + unsigned long lowmem_kbytes; + int new_min_free_kbytes; + + lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); + new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16); + + if (new_min_free_kbytes > user_min_free_kbytes) { + min_free_kbytes = new_min_free_kbytes; + if (min_free_kbytes < 128) + min_free_kbytes = 128; + if (min_free_kbytes > 65536) + min_free_kbytes = 65536; + } else { + pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n", + new_min_free_kbytes, user_min_free_kbytes); + } + setup_per_zone_wmarks(); + refresh_zone_stat_thresholds(); + setup_per_zone_lowmem_reserve(); + +#ifdef CONFIG_NUMA + setup_min_unmapped_ratio(); + setup_min_slab_ratio(); +#endif + + khugepaged_min_free_kbytes_update(); + + return 0; +} +postcore_initcall(init_per_zone_wmark_min) + +/* + * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so + * that we can call two helper functions whenever min_free_kbytes + * changes. + */ +int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *length, loff_t *ppos) +{ + int rc; + + rc = proc_dointvec_minmax(table, write, buffer, length, ppos); + if (rc) + return rc; + + if (write) { + user_min_free_kbytes = min_free_kbytes; + setup_per_zone_wmarks(); + } + return 0; +} + +int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *length, loff_t *ppos) +{ + int rc; + + rc = proc_dointvec_minmax(table, write, buffer, length, ppos); + if (rc) + return rc; + + if (write) + setup_per_zone_wmarks(); + + return 0; +} + +#ifdef CONFIG_NUMA +static void setup_min_unmapped_ratio(void) +{ + pg_data_t *pgdat; + struct zone *zone; + + for_each_online_pgdat(pgdat) + pgdat->min_unmapped_pages = 0; + + for_each_zone(zone) + zone->zone_pgdat->min_unmapped_pages += (zone->managed_pages * + sysctl_min_unmapped_ratio) / 100; +} + + +int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *length, loff_t *ppos) +{ + int rc; + + rc = proc_dointvec_minmax(table, write, buffer, length, ppos); + if (rc) + return rc; + + setup_min_unmapped_ratio(); + + return 0; +} + +static void setup_min_slab_ratio(void) +{ + pg_data_t *pgdat; + struct zone *zone; + + for_each_online_pgdat(pgdat) + pgdat->min_slab_pages = 0; + + for_each_zone(zone) + zone->zone_pgdat->min_slab_pages += (zone->managed_pages * + sysctl_min_slab_ratio) / 100; +} + +int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *length, loff_t *ppos) +{ + int rc; + + rc = proc_dointvec_minmax(table, write, buffer, length, ppos); + if (rc) + return rc; + + setup_min_slab_ratio(); + + return 0; +} +#endif + +/* + * lowmem_reserve_ratio_sysctl_handler - just a wrapper around + * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() + * whenever sysctl_lowmem_reserve_ratio changes. + * + * The reserve ratio obviously has absolutely no relation with the + * minimum watermarks. The lowmem reserve ratio can only make sense + * if in function of the boot time zone sizes. + */ +int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *length, loff_t *ppos) +{ + proc_dointvec_minmax(table, write, buffer, length, ppos); + setup_per_zone_lowmem_reserve(); + return 0; +} + +/* + * percpu_pagelist_fraction - changes the pcp->high for each zone on each + * cpu. It is the fraction of total pages in each zone that a hot per cpu + * pagelist can have before it gets flushed back to buddy allocator. + */ +int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *length, loff_t *ppos) +{ + struct zone *zone; + int old_percpu_pagelist_fraction; + int ret; + + mutex_lock(&pcp_batch_high_lock); + old_percpu_pagelist_fraction = percpu_pagelist_fraction; + + ret = proc_dointvec_minmax(table, write, buffer, length, ppos); + if (!write || ret < 0) + goto out; + + /* Sanity checking to avoid pcp imbalance */ + if (percpu_pagelist_fraction && + percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) { + percpu_pagelist_fraction = old_percpu_pagelist_fraction; + ret = -EINVAL; + goto out; + } + + /* No change? */ + if (percpu_pagelist_fraction == old_percpu_pagelist_fraction) + goto out; + + for_each_populated_zone(zone) { + unsigned int cpu; + + for_each_possible_cpu(cpu) + pageset_set_high_and_batch(zone, + per_cpu_ptr(zone->pageset, cpu)); + } +out: + mutex_unlock(&pcp_batch_high_lock); + return ret; +} + +#ifdef CONFIG_NUMA +int hashdist = HASHDIST_DEFAULT; + +static int __init set_hashdist(char *str) +{ + if (!str) + return 0; + hashdist = simple_strtoul(str, &str, 0); + return 1; +} +__setup("hashdist=", set_hashdist); +#endif + +#ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES +/* + * Returns the number of pages that arch has reserved but + * is not known to alloc_large_system_hash(). + */ +static unsigned long __init arch_reserved_kernel_pages(void) +{ + return 0; +} +#endif + +/* + * Adaptive scale is meant to reduce sizes of hash tables on large memory + * machines. As memory size is increased the scale is also increased but at + * slower pace. Starting from ADAPT_SCALE_BASE (64G), every time memory + * quadruples the scale is increased by one, which means the size of hash table + * only doubles, instead of quadrupling as well. + * Because 32-bit systems cannot have large physical memory, where this scaling + * makes sense, it is disabled on such platforms. + */ +#if __BITS_PER_LONG > 32 +#define ADAPT_SCALE_BASE (64ul << 30) +#define ADAPT_SCALE_SHIFT 2 +#define ADAPT_SCALE_NPAGES (ADAPT_SCALE_BASE >> PAGE_SHIFT) +#endif + +/* + * allocate a large system hash table from bootmem + * - it is assumed that the hash table must contain an exact power-of-2 + * quantity of entries + * - limit is the number of hash buckets, not the total allocation size + */ +void *__init alloc_large_system_hash(const char *tablename, + unsigned long bucketsize, + unsigned long numentries, + int scale, + int flags, + unsigned int *_hash_shift, + unsigned int *_hash_mask, + unsigned long low_limit, + unsigned long high_limit) +{ + unsigned long long max = high_limit; + unsigned long log2qty, size; + void *table = NULL; + gfp_t gfp_flags; + + /* allow the kernel cmdline to have a say */ + if (!numentries) { + /* round applicable memory size up to nearest megabyte */ + numentries = nr_kernel_pages; + numentries -= arch_reserved_kernel_pages(); + + /* It isn't necessary when PAGE_SIZE >= 1MB */ + if (PAGE_SHIFT < 20) + numentries = round_up(numentries, (1<<20)/PAGE_SIZE); + +#if __BITS_PER_LONG > 32 + if (!high_limit) { + unsigned long adapt; + + for (adapt = ADAPT_SCALE_NPAGES; adapt < numentries; + adapt <<= ADAPT_SCALE_SHIFT) + scale++; + } +#endif + + /* limit to 1 bucket per 2^scale bytes of low memory */ + if (scale > PAGE_SHIFT) + numentries >>= (scale - PAGE_SHIFT); + else + numentries <<= (PAGE_SHIFT - scale); + + /* Make sure we've got at least a 0-order allocation.. */ + if (unlikely(flags & HASH_SMALL)) { + /* Makes no sense without HASH_EARLY */ + WARN_ON(!(flags & HASH_EARLY)); + if (!(numentries >> *_hash_shift)) { + numentries = 1UL << *_hash_shift; + BUG_ON(!numentries); + } + } else if (unlikely((numentries * bucketsize) < PAGE_SIZE)) + numentries = PAGE_SIZE / bucketsize; + } + numentries = roundup_pow_of_two(numentries); + + /* limit allocation size to 1/16 total memory by default */ + if (max == 0) { + max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4; + do_div(max, bucketsize); + } + max = min(max, 0x80000000ULL); + + if (numentries < low_limit) + numentries = low_limit; + if (numentries > max) + numentries = max; + + log2qty = ilog2(numentries); + + gfp_flags = (flags & HASH_ZERO) ? GFP_ATOMIC | __GFP_ZERO : GFP_ATOMIC; + do { + size = bucketsize << log2qty; + if (flags & HASH_EARLY) { + if (flags & HASH_ZERO) + table = memblock_virt_alloc_nopanic(size, 0); + else + table = memblock_virt_alloc_raw(size, 0); + } else if (hashdist) { + table = __vmalloc(size, gfp_flags, PAGE_KERNEL); + } else { + /* + * If bucketsize is not a power-of-two, we may free + * some pages at the end of hash table which + * alloc_pages_exact() automatically does + */ + if (get_order(size) < MAX_ORDER) { + table = alloc_pages_exact(size, gfp_flags); + kmemleak_alloc(table, size, 1, gfp_flags); + } + } + } while (!table && size > PAGE_SIZE && --log2qty); + + if (!table) + panic("Failed to allocate %s hash table\n", tablename); + + pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n", + tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size); + + if (_hash_shift) + *_hash_shift = log2qty; + if (_hash_mask) + *_hash_mask = (1 << log2qty) - 1; + + return table; +} + +/* + * This function checks whether pageblock includes unmovable pages or not. + * If @count is not zero, it is okay to include less @count unmovable pages + * + * PageLRU check without isolation or lru_lock could race so that + * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable + * check without lock_page also may miss some movable non-lru pages at + * race condition. So you can't expect this function should be exact. + */ +bool has_unmovable_pages(struct zone *zone, struct page *page, int count, + int migratetype, + bool skip_hwpoisoned_pages) +{ + unsigned long pfn, iter, found; + + /* + * TODO we could make this much more efficient by not checking every + * page in the range if we know all of them are in MOVABLE_ZONE and + * that the movable zone guarantees that pages are migratable but + * the later is not the case right now unfortunatelly. E.g. movablecore + * can still lead to having bootmem allocations in zone_movable. + */ + + /* + * CMA allocations (alloc_contig_range) really need to mark isolate + * CMA pageblocks even when they are not movable in fact so consider + * them movable here. + */ + if (is_migrate_cma(migratetype) && + is_migrate_cma(get_pageblock_migratetype(page))) + return false; + + pfn = page_to_pfn(page); + for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) { + unsigned long check = pfn + iter; + + if (!pfn_valid_within(check)) + continue; + + page = pfn_to_page(check); + + if (PageReserved(page)) + goto unmovable; + + /* + * If the zone is movable and we have ruled out all reserved + * pages then it should be reasonably safe to assume the rest + * is movable. + */ + if (zone_idx(zone) == ZONE_MOVABLE) + continue; + + /* + * Hugepages are not in LRU lists, but they're movable. + * We need not scan over tail pages bacause we don't + * handle each tail page individually in migration. + */ + if (PageHuge(page)) { + struct page *head = compound_head(page); + unsigned int skip_pages; + + if (!hugepage_migration_supported(page_hstate(head))) + goto unmovable; + + skip_pages = (1 << compound_order(head)) - (page - head); + iter += skip_pages - 1; + continue; + } + + /* + * We can't use page_count without pin a page + * because another CPU can free compound page. + * This check already skips compound tails of THP + * because their page->_refcount is zero at all time. + */ + if (!page_ref_count(page)) { + if (PageBuddy(page)) + iter += (1 << page_order(page)) - 1; + continue; + } + + /* + * The HWPoisoned page may be not in buddy system, and + * page_count() is not 0. + */ + if (skip_hwpoisoned_pages && PageHWPoison(page)) + continue; + + if (__PageMovable(page)) + continue; + + if (!PageLRU(page)) + found++; + /* + * If there are RECLAIMABLE pages, we need to check + * it. But now, memory offline itself doesn't call + * shrink_node_slabs() and it still to be fixed. + */ + /* + * If the page is not RAM, page_count()should be 0. + * we don't need more check. This is an _used_ not-movable page. + * + * The problematic thing here is PG_reserved pages. PG_reserved + * is set to both of a memory hole page and a _used_ kernel + * page at boot. + */ + if (found > count) + goto unmovable; + } + return false; +unmovable: + WARN_ON_ONCE(zone_idx(zone) == ZONE_MOVABLE); + return true; +} + +#if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA) + +static unsigned long pfn_max_align_down(unsigned long pfn) +{ + return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES, + pageblock_nr_pages) - 1); +} + +static unsigned long pfn_max_align_up(unsigned long pfn) +{ + return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES, + pageblock_nr_pages)); +} + +/* [start, end) must belong to a single zone. */ +static int __alloc_contig_migrate_range(struct compact_control *cc, + unsigned long start, unsigned long end) +{ + /* This function is based on compact_zone() from compaction.c. */ + unsigned long nr_reclaimed; + unsigned long pfn = start; + unsigned int tries = 0; + int ret = 0; + + migrate_prep(); + + while (pfn < end || !list_empty(&cc->migratepages)) { + if (fatal_signal_pending(current)) { + ret = -EINTR; + break; + } + + if (list_empty(&cc->migratepages)) { + cc->nr_migratepages = 0; + pfn = isolate_migratepages_range(cc, pfn, end); + if (!pfn) { + ret = -EINTR; + break; + } + tries = 0; + } else if (++tries == 5) { + ret = ret < 0 ? ret : -EBUSY; + break; + } + + nr_reclaimed = reclaim_clean_pages_from_list(cc->zone, + &cc->migratepages); + cc->nr_migratepages -= nr_reclaimed; + + ret = migrate_pages(&cc->migratepages, alloc_migrate_target, + NULL, 0, cc->mode, MR_CONTIG_RANGE); + } + if (ret < 0) { + putback_movable_pages(&cc->migratepages); + return ret; + } + return 0; +} + +/** + * alloc_contig_range() -- tries to allocate given range of pages + * @start: start PFN to allocate + * @end: one-past-the-last PFN to allocate + * @migratetype: migratetype of the underlaying pageblocks (either + * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks + * in range must have the same migratetype and it must + * be either of the two. + * @gfp_mask: GFP mask to use during compaction + * + * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES + * aligned. The PFN range must belong to a single zone. + * + * The first thing this routine does is attempt to MIGRATE_ISOLATE all + * pageblocks in the range. Once isolated, the pageblocks should not + * be modified by others. + * + * Returns zero on success or negative error code. On success all + * pages which PFN is in [start, end) are allocated for the caller and + * need to be freed with free_contig_range(). + */ +int alloc_contig_range(unsigned long start, unsigned long end, + unsigned migratetype, gfp_t gfp_mask) +{ + unsigned long outer_start, outer_end; + unsigned int order; + int ret = 0; + + struct compact_control cc = { + .nr_migratepages = 0, + .order = -1, + .zone = page_zone(pfn_to_page(start)), + .mode = MIGRATE_SYNC, + .ignore_skip_hint = true, + .no_set_skip_hint = true, + .gfp_mask = current_gfp_context(gfp_mask), + }; + INIT_LIST_HEAD(&cc.migratepages); + + /* + * What we do here is we mark all pageblocks in range as + * MIGRATE_ISOLATE. Because pageblock and max order pages may + * have different sizes, and due to the way page allocator + * work, we align the range to biggest of the two pages so + * that page allocator won't try to merge buddies from + * different pageblocks and change MIGRATE_ISOLATE to some + * other migration type. + * + * Once the pageblocks are marked as MIGRATE_ISOLATE, we + * migrate the pages from an unaligned range (ie. pages that + * we are interested in). This will put all the pages in + * range back to page allocator as MIGRATE_ISOLATE. + * + * When this is done, we take the pages in range from page + * allocator removing them from the buddy system. This way + * page allocator will never consider using them. + * + * This lets us mark the pageblocks back as + * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the + * aligned range but not in the unaligned, original range are + * put back to page allocator so that buddy can use them. + */ + + ret = start_isolate_page_range(pfn_max_align_down(start), + pfn_max_align_up(end), migratetype, + false); + if (ret) + return ret; + + /* + * In case of -EBUSY, we'd like to know which page causes problem. + * So, just fall through. test_pages_isolated() has a tracepoint + * which will report the busy page. + * + * It is possible that busy pages could become available before + * the call to test_pages_isolated, and the range will actually be + * allocated. So, if we fall through be sure to clear ret so that + * -EBUSY is not accidentally used or returned to caller. + */ + ret = __alloc_contig_migrate_range(&cc, start, end); + if (ret && ret != -EBUSY) + goto done; + ret =0; + + /* + * Pages from [start, end) are within a MAX_ORDER_NR_PAGES + * aligned blocks that are marked as MIGRATE_ISOLATE. What's + * more, all pages in [start, end) are free in page allocator. + * What we are going to do is to allocate all pages from + * [start, end) (that is remove them from page allocator). + * + * The only problem is that pages at the beginning and at the + * end of interesting range may be not aligned with pages that + * page allocator holds, ie. they can be part of higher order + * pages. Because of this, we reserve the bigger range and + * once this is done free the pages we are not interested in. + * + * We don't have to hold zone->lock here because the pages are + * isolated thus they won't get removed from buddy. + */ + + lru_add_drain_all(); + drain_all_pages(cc.zone); + + order = 0; + outer_start = start; + while (!PageBuddy(pfn_to_page(outer_start))) { + if (++order >= MAX_ORDER) { + outer_start = start; + break; + } + outer_start &= ~0UL << order; + } + + if (outer_start != start) { + order = page_order(pfn_to_page(outer_start)); + + /* + * outer_start page could be small order buddy page and + * it doesn't include start page. Adjust outer_start + * in this case to report failed page properly + * on tracepoint in test_pages_isolated() + */ + if (outer_start + (1UL << order) <= start) + outer_start = start; + } + + /* Make sure the range is really isolated. */ + if (test_pages_isolated(outer_start, end, false)) { + pr_info_ratelimited("%s: [%lx, %lx) PFNs busy\n", + __func__, outer_start, end); + ret = -EBUSY; + goto done; + } + + /* Grab isolated pages from freelists. */ + outer_end = isolate_freepages_range(&cc, outer_start, end); + if (!outer_end) { + ret = -EBUSY; + goto done; + } + + /* Free head and tail (if any) */ + if (start != outer_start) + free_contig_range(outer_start, start - outer_start); + if (end != outer_end) + free_contig_range(end, outer_end - end); + +done: + undo_isolate_page_range(pfn_max_align_down(start), + pfn_max_align_up(end), migratetype); + return ret; +} + +void free_contig_range(unsigned long pfn, unsigned nr_pages) +{ + unsigned int count = 0; + + for (; nr_pages--; pfn++) { + struct page *page = pfn_to_page(pfn); + + count += page_count(page) != 1; + __free_page(page); + } + WARN(count != 0, "%d pages are still in use!\n", count); +} +#endif + +/* + * The zone indicated has a new number of managed_pages; batch sizes and percpu + * page high values need to be recalulated. + */ +void __meminit zone_pcp_update(struct zone *zone) +{ + unsigned cpu; + mutex_lock(&pcp_batch_high_lock); + for_each_possible_cpu(cpu) + pageset_set_high_and_batch(zone, + per_cpu_ptr(zone->pageset, cpu)); + mutex_unlock(&pcp_batch_high_lock); +} + +void zone_pcp_reset(struct zone *zone) +{ + unsigned long flags; + int cpu; + struct per_cpu_pageset *pset; + + /* avoid races with drain_pages() */ + local_irq_save(flags); + if (zone->pageset != &boot_pageset) { + for_each_online_cpu(cpu) { + pset = per_cpu_ptr(zone->pageset, cpu); + drain_zonestat(zone, pset); + } + free_percpu(zone->pageset); + zone->pageset = &boot_pageset; + } + local_irq_restore(flags); +} + +#ifdef CONFIG_MEMORY_HOTREMOVE +/* + * All pages in the range must be in a single zone and isolated + * before calling this. + */ +void +__offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) +{ + struct page *page; + struct zone *zone; + unsigned int order, i; + unsigned long pfn; + unsigned long flags; + /* find the first valid pfn */ + for (pfn = start_pfn; pfn < end_pfn; pfn++) + if (pfn_valid(pfn)) + break; + if (pfn == end_pfn) + return; + offline_mem_sections(pfn, end_pfn); + zone = page_zone(pfn_to_page(pfn)); + spin_lock_irqsave(&zone->lock, flags); + pfn = start_pfn; + while (pfn < end_pfn) { + if (!pfn_valid(pfn)) { + pfn++; + continue; + } + page = pfn_to_page(pfn); + /* + * The HWPoisoned page may be not in buddy system, and + * page_count() is not 0. + */ + if (unlikely(!PageBuddy(page) && PageHWPoison(page))) { + pfn++; + SetPageReserved(page); + continue; + } + + BUG_ON(page_count(page)); + BUG_ON(!PageBuddy(page)); + order = page_order(page); +#ifdef CONFIG_DEBUG_VM + pr_info("remove from free list %lx %d %lx\n", + pfn, 1 << order, end_pfn); +#endif + list_del(&page->lru); + rmv_page_order(page); + zone->free_area[order].nr_free--; + for (i = 0; i < (1 << order); i++) + SetPageReserved((page+i)); + pfn += (1 << order); + } + spin_unlock_irqrestore(&zone->lock, flags); +} +#endif + +bool is_free_buddy_page(struct page *page) +{ + struct zone *zone = page_zone(page); + unsigned long pfn = page_to_pfn(page); + unsigned long flags; + unsigned int order; + + spin_lock_irqsave(&zone->lock, flags); + for (order = 0; order < MAX_ORDER; order++) { + struct page *page_head = page - (pfn & ((1 << order) - 1)); + + if (PageBuddy(page_head) && page_order(page_head) >= order) + break; + } + spin_unlock_irqrestore(&zone->lock, flags); + + return order < MAX_ORDER; +} + +#ifdef CONFIG_MEMORY_FAILURE +/* + * Set PG_hwpoison flag if a given page is confirmed to be a free page. This + * test is performed under the zone lock to prevent a race against page + * allocation. + */ +bool set_hwpoison_free_buddy_page(struct page *page) +{ + struct zone *zone = page_zone(page); + unsigned long pfn = page_to_pfn(page); + unsigned long flags; + unsigned int order; + bool hwpoisoned = false; + + spin_lock_irqsave(&zone->lock, flags); + for (order = 0; order < MAX_ORDER; order++) { + struct page *page_head = page - (pfn & ((1 << order) - 1)); + + if (PageBuddy(page_head) && page_order(page_head) >= order) { + if (!TestSetPageHWPoison(page)) + hwpoisoned = true; + break; + } + } + spin_unlock_irqrestore(&zone->lock, flags); + + return hwpoisoned; +} +#endif |