--- /dev/null
+/*
+ * 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/kmemcheck.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/notifier.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/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 <linux/prefetch.h>
+#include <linux/mm_inline.h>
+#include <linux/migrate.h>
+#include <linux/page_ext.h>
+#include <linux/hugetlb.h>
+#include <linux/sched/rt.h>
+#include <linux/locallock.h>
+#include <linux/page_owner.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
+
+#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
+
+/*
+ * 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
+#ifdef CONFIG_MOVABLE_NODE
+ [N_MEMORY] = { { [0] = 1UL } },
+#endif
+ [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;
+/*
+ * When calculating the number of globally allowed dirty pages, there
+ * is a certain number of per-zone reserves that should not be
+ * considered dirtyable memory. This is the sum of those reserves
+ * over all existing zones that contribute dirtyable memory.
+ */
+unsigned long dirty_balance_reserve __read_mostly;
+
+int percpu_pagelist_fraction;
+gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
+
+#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 pm_mutex held (gfp_allowed_mask also should
+ * only be modified with pm_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(&pm_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(&pm_mutex));
+ WARN_ON(saved_gfp_mask);
+ saved_gfp_mask = gfp_allowed_mask;
+ gfp_allowed_mask &= ~GFP_IOFS;
+}
+
+bool pm_suspended_storage(void)
+{
+ if ((gfp_allowed_mask & GFP_IOFS) == GFP_IOFS)
+ return false;
+ return true;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
+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-1] = {
+#ifdef CONFIG_ZONE_DMA
+ 256,
+#endif
+#ifdef CONFIG_ZONE_DMA32
+ 256,
+#endif
+#ifdef CONFIG_HIGHMEM
+ 32,
+#endif
+ 32,
+};
+
+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",
+};
+
+int min_free_kbytes = 1024;
+int user_min_free_kbytes = -1;
+
+static unsigned long __meminitdata nr_kernel_pages;
+static unsigned long __meminitdata nr_all_pages;
+static unsigned long __meminitdata dma_reserve;
+
+#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
+static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
+static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
+static unsigned long __initdata required_kernelcore;
+static unsigned long __initdata required_movablecore;
+static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
+
+/* 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
+
+static DEFINE_LOCAL_IRQ_LOCK(pa_lock);
+
+#ifdef CONFIG_PREEMPT_RT_BASE
+# define cpu_lock_irqsave(cpu, flags) \
+ local_lock_irqsave_on(pa_lock, flags, cpu)
+# define cpu_unlock_irqrestore(cpu, flags) \
+ local_unlock_irqrestore_on(pa_lock, flags, cpu)
+#else
+# define cpu_lock_irqsave(cpu, flags) local_irq_save(flags)
+# define cpu_unlock_irqrestore(cpu, flags) local_irq_restore(flags)
+#endif
+
+int page_group_by_mobility_disabled __read_mostly;
+
+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 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 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;
+
+ /* Don't complain about poisoned pages */
+ if (PageHWPoison(page)) {
+ page_mapcount_reset(page); /* remove PageBuddy */
+ return;
+ }
+
+ /*
+ * 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) {
+ printk(KERN_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;
+
+ printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n",
+ current->comm, page_to_pfn(page));
+ dump_page_badflags(page, reason, bad_flags);
+
+ 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".
+ *
+ * The remaining PAGE_SIZE pages are called "tail pages".
+ *
+ * All pages have PG_compound set. All tail pages have their ->first_page
+ * pointing at the head page.
+ *
+ * The first tail page's ->lru.next holds the address of the compound page's
+ * put_page() function. Its ->lru.prev holds the order of allocation.
+ * This usage means that zero-order pages may not be compound.
+ */
+
+static void free_compound_page(struct page *page)
+{
+ __free_pages_ok(page, compound_order(page));
+}
+
+void prep_compound_page(struct page *page, unsigned long order)
+{
+ int i;
+ int nr_pages = 1 << order;
+
+ set_compound_page_dtor(page, free_compound_page);
+ 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->first_page = page;
+ /* Make sure p->first_page is always valid for PageTail() */
+ smp_wmb();
+ __SetPageTail(p);
+ }
+}
+
+static inline void prep_zero_page(struct page *page, unsigned int order,
+ gfp_t gfp_flags)
+{
+ int i;
+
+ /*
+ * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
+ * and __GFP_HIGHMEM from hard or soft interrupt context.
+ */
+ VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt());
+ for (i = 0; i < (1 << order); i++)
+ clear_highpage(page + i);
+}
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+unsigned int _debug_guardpage_minorder;
+bool _debug_pagealloc_enabled __read_mostly;
+bool _debug_guardpage_enabled __read_mostly;
+
+static int __init early_debug_pagealloc(char *buf)
+{
+ if (!buf)
+ return -EINVAL;
+
+ if (strcmp(buf, "on") == 0)
+ _debug_pagealloc_enabled = true;
+
+ return 0;
+}
+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;
+
+ return true;
+}
+
+static void init_debug_guardpage(void)
+{
+ if (!debug_pagealloc_enabled())
+ 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) {
+ printk(KERN_ERR "Bad debug_guardpage_minorder value\n");
+ return 0;
+ }
+ _debug_guardpage_minorder = res;
+ printk(KERN_INFO "Setting debug_guardpage_minorder to %lu\n", res);
+ return 0;
+}
+__setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup);
+
+static inline void set_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);
+ __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);
+}
+
+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);
+ __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 = { NULL, };
+static inline void set_page_guard(struct zone *zone, struct page *page,
+ unsigned int order, int migratetype) {}
+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 do coalesce a page and its buddy if
+ * (a) the buddy is not in a hole &&
+ * (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 ->_mapcount
+ * PAGE_BUDDY_MAPCOUNT_VALUE.
+ * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE 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 (!pfn_valid_within(page_to_pfn(buddy)))
+ return 0;
+
+ 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 _mapcount
+ * PAGE_BUDDY_MAPCOUNT_VALUE. 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 page_idx;
+ unsigned long combined_idx;
+ unsigned long uninitialized_var(buddy_idx);
+ struct page *buddy;
+ int max_order = MAX_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 (is_migrate_isolate(migratetype)) {
+ /*
+ * We restrict max order of merging to prevent merge
+ * between freepages on isolate pageblock and normal
+ * pageblock. Without this, pageblock isolation
+ * could cause incorrect freepage accounting.
+ */
+ max_order = min(MAX_ORDER, pageblock_order + 1);
+ } else {
+ __mod_zone_freepage_state(zone, 1 << order, migratetype);
+ }
+
+ page_idx = pfn & ((1 << max_order) - 1);
+
+ VM_BUG_ON_PAGE(page_idx & ((1 << order) - 1), page);
+ VM_BUG_ON_PAGE(bad_range(zone, page), page);
+
+ while (order < max_order - 1) {
+ buddy_idx = __find_buddy_index(page_idx, order);
+ buddy = page + (buddy_idx - page_idx);
+ if (!page_is_buddy(page, buddy, order))
+ break;
+ /*
+ * 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_idx = buddy_idx & page_idx;
+ page = page + (combined_idx - page_idx);
+ page_idx = combined_idx;
+ order++;
+ }
+ 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(page_to_pfn(buddy))) {
+ struct page *higher_page, *higher_buddy;
+ combined_idx = buddy_idx & page_idx;
+ higher_page = page + (combined_idx - page_idx);
+ buddy_idx = __find_buddy_index(combined_idx, order + 1);
+ higher_buddy = higher_page + (buddy_idx - combined_idx);
+ if (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++;
+}
+
+static inline int free_pages_check(struct page *page)
+{
+ const char *bad_reason = NULL;
+ unsigned long bad_flags = 0;
+
+ if (unlikely(page_mapcount(page)))
+ bad_reason = "nonzero mapcount";
+ if (unlikely(page->mapping != NULL))
+ bad_reason = "non-NULL mapping";
+ if (unlikely(atomic_read(&page->_count) != 0))
+ bad_reason = "nonzero _count";
+ 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
+ if (unlikely(bad_reason)) {
+ bad_page(page, bad_reason, bad_flags);
+ return 1;
+ }
+ page_cpupid_reset_last(page);
+ if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
+ page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
+ return 0;
+}
+
+/*
+ * Frees a number of pages which have been collected 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 list_head *list)
+{
+ int to_free = count;
+ unsigned long nr_scanned;
+ unsigned long flags;
+
+ spin_lock_irqsave(&zone->lock, flags);
+
+ nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
+ if (nr_scanned)
+ __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
+
+ while (!list_empty(list)) {
+ struct page *page = list_first_entry(list, struct page, lru);
+ int mt; /* migratetype of the to-be-freed page */
+
+ /* must delete as __free_one_page list manipulates */
+ list_del(&page->lru);
+
+ mt = get_freepage_migratetype(page);
+ if (unlikely(has_isolate_pageblock(zone)))
+ mt = get_pageblock_migratetype(page);
+
+ /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
+ __free_one_page(page, page_to_pfn(page), zone, 0, mt);
+ trace_mm_page_pcpu_drain(page, 0, mt);
+ to_free--;
+ }
+ WARN_ON(to_free != 0);
+ spin_unlock_irqrestore(&zone->lock, flags);
+}
+
+/*
+ * Moves a number of pages from the PCP lists to free list which
+ * is freed outside of the locked region.
+ *
+ * Assumes all pages on list are in same zone, and of same order.
+ * count is the number of pages to free.
+ */
+static void isolate_pcp_pages(int to_free, struct per_cpu_pages *src,
+ struct list_head *dst)
+{
+ int migratetype = 0;
+ int batch_free = 0;
+
+ while (to_free) {
+ struct page *page;
+ 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 = &src->lists[migratetype];
+ } while (list_empty(list));
+
+ /* This is the only non-empty list. Free them all. */
+ if (batch_free == MIGRATE_PCPTYPES)
+ batch_free = to_free;
+
+ do {
+ page = list_last_entry(list, struct page, lru);
+ list_del(&page->lru);
+ list_add(&page->lru, dst);
+ } while (--to_free && --batch_free && !list_empty(list));
+ }
+}
+
+static void free_one_page(struct zone *zone,
+ struct page *page, unsigned long pfn,
+ unsigned int order,
+ int migratetype)
+{
+ unsigned long nr_scanned;
+ unsigned long flags;
+
+ spin_lock_irqsave(&zone->lock, flags);
+ nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
+ if (nr_scanned)
+ __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
+
+ 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_irqrestore(&zone->lock, flags);
+}
+
+static int free_tail_pages_check(struct page *head_page, struct page *page)
+{
+ if (!IS_ENABLED(CONFIG_DEBUG_VM))
+ return 0;
+ if (unlikely(!PageTail(page))) {
+ bad_page(page, "PageTail not set", 0);
+ return 1;
+ }
+ if (unlikely(page->first_page != head_page)) {
+ bad_page(page, "first_page not consistent", 0);
+ return 1;
+ }
+ return 0;
+}
+
+static bool free_pages_prepare(struct page *page, unsigned int order)
+{
+ bool compound = PageCompound(page);
+ int i, bad = 0;
+
+ VM_BUG_ON_PAGE(PageTail(page), page);
+ VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
+
+ trace_mm_page_free(page, order);
+ kmemcheck_free_shadow(page, order);
+ kasan_free_pages(page, order);
+
+ if (PageAnon(page))
+ page->mapping = NULL;
+ bad += free_pages_check(page);
+ for (i = 1; i < (1 << order); i++) {
+ if (compound)
+ bad += free_tail_pages_check(page, page + i);
+ bad += free_pages_check(page + i);
+ }
+ if (bad)
+ return false;
+
+ 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_map_pages(page, 1 << order, 0);
+
+ return true;
+}
+
+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))
+ return;
+
+ migratetype = get_pfnblock_migratetype(page, pfn);
+ local_lock_irqsave(pa_lock, flags);
+ __count_vm_events(PGFREE, 1 << order);
+ set_freepage_migratetype(page, migratetype);
+ free_one_page(page_zone(page), page, pfn, order, migratetype);
+ local_unlock_irqrestore(pa_lock, flags);
+}
+
+void __init __free_pages_bootmem(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);
+}
+
+#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]);
+
+ if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) &&
+ debug_guardpage_enabled() &&
+ high < debug_guardpage_minorder()) {
+ /*
+ * 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
+ */
+ 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);
+ }
+}
+
+/*
+ * This page is about to be returned from the page allocator
+ */
+static inline int check_new_page(struct page *page)
+{
+ const char *bad_reason = NULL;
+ unsigned long bad_flags = 0;
+
+ if (unlikely(page_mapcount(page)))
+ bad_reason = "nonzero mapcount";
+ if (unlikely(page->mapping != NULL))
+ bad_reason = "non-NULL mapping";
+ if (unlikely(atomic_read(&page->_count) != 0))
+ bad_reason = "nonzero _count";
+ 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
+ if (unlikely(bad_reason)) {
+ bad_page(page, bad_reason, bad_flags);
+ return 1;
+ }
+ return 0;
+}
+
+static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
+ int alloc_flags)
+{
+ int i;
+
+ for (i = 0; i < (1 << order); i++) {
+ struct page *p = page + i;
+ if (unlikely(check_new_page(p)))
+ return 1;
+ }
+
+ 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);
+
+ if (gfp_flags & __GFP_ZERO)
+ prep_zero_page(page, order, gfp_flags);
+
+ if (order && (gfp_flags & __GFP_COMP))
+ prep_compound_page(page, order);
+
+ set_page_owner(page, order, gfp_flags);
+
+ /*
+ * page->pfmemalloc is set 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.
+ */
+ page->pfmemalloc = !!(alloc_flags & ALLOC_NO_WATERMARKS);
+
+ return 0;
+}
+
+/*
+ * Go through the free lists for the given migratetype and remove
+ * the smallest available page from the freelists
+ */
+static 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]);
+ if (list_empty(&area->free_list[migratetype]))
+ continue;
+
+ page = list_entry(area->free_list[migratetype].next,
+ struct page, lru);
+ list_del(&page->lru);
+ rmv_page_order(page);
+ area->nr_free--;
+ expand(zone, page, order, current_order, area, migratetype);
+ set_freepage_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_RESERVE },
+ [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
+ [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
+#ifdef CONFIG_CMA
+ [MIGRATE_CMA] = { MIGRATE_RESERVE }, /* Never used */
+#endif
+ [MIGRATE_RESERVE] = { MIGRATE_RESERVE }, /* Never used */
+#ifdef CONFIG_MEMORY_ISOLATION
+ [MIGRATE_ISOLATE] = { MIGRATE_RESERVE }, /* Never used */
+#endif
+};
+
+#ifdef CONFIG_CMA
+static 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()
+ */
+int move_freepages(struct zone *zone,
+ struct page *start_page, struct page *end_page,
+ int migratetype)
+{
+ struct page *page;
+ unsigned long 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(page_zone(start_page) != page_zone(end_page));
+#endif
+
+ for (page = start_page; page <= end_page;) {
+ /* Make sure we are not inadvertently changing nodes */
+ VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
+
+ if (!pfn_valid_within(page_to_pfn(page))) {
+ page++;
+ continue;
+ }
+
+ if (!PageBuddy(page)) {
+ page++;
+ continue;
+ }
+
+ order = page_order(page);
+ list_move(&page->lru,
+ &zone->free_area[order].free_list[migratetype]);
+ set_freepage_migratetype(page, migratetype);
+ page += 1 << order;
+ pages_moved += 1 << order;
+ }
+
+ return pages_moved;
+}
+
+int move_freepages_block(struct zone *zone, struct page *page,
+ int migratetype)
+{
+ 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);
+}
+
+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 and check whether half of pages are moved or not. If half of
+ * pages are moved, we can change migratetype of pageblock and permanently
+ * use it's pages as requested migratetype in the future.
+ */
+static void steal_suitable_fallback(struct zone *zone, struct page *page,
+ int start_type)
+{
+ int current_order = page_order(page);
+ int pages;
+
+ /* Take ownership for orders >= pageblock_order */
+ if (current_order >= pageblock_order) {
+ change_pageblock_range(page, current_order, start_type);
+ return;
+ }
+
+ pages = move_freepages_block(zone, page, start_type);
+
+ /* Claim the whole block if over half of it is free */
+ if (pages >= (1 << (pageblock_order-1)) ||
+ page_group_by_mobility_disabled)
+ set_pageblock_migratetype(page, 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_RESERVE)
+ 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;
+}
+
+/* Remove an element from the buddy allocator from the fallback list */
+static inline struct page *
+__rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
+{
+ struct free_area *area;
+ unsigned int current_order;
+ struct page *page;
+ int fallback_mt;
+ bool can_steal;
+
+ /* Find the largest possible block of pages in the other list */
+ for (current_order = MAX_ORDER-1;
+ current_order >= order && current_order <= MAX_ORDER-1;
+ --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;
+
+ page = list_entry(area->free_list[fallback_mt].next,
+ struct page, lru);
+ if (can_steal)
+ steal_suitable_fallback(zone, page, start_migratetype);
+
+ /* Remove the page from the freelists */
+ area->nr_free--;
+ list_del(&page->lru);
+ rmv_page_order(page);
+
+ expand(zone, page, order, current_order, area,
+ start_migratetype);
+ /*
+ * The freepage_migratetype may differ from pageblock's
+ * migratetype depending on the decisions in
+ * try_to_steal_freepages(). This is OK as long as it
+ * does not differ for MIGRATE_CMA pageblocks. For CMA
+ * we need to make sure unallocated pages flushed from
+ * pcp lists are returned to the correct freelist.
+ */
+ set_freepage_migratetype(page, start_migratetype);
+
+ trace_mm_page_alloc_extfrag(page, order, current_order,
+ start_migratetype, fallback_mt);
+
+ return page;
+ }
+
+ return NULL;
+}
+
+/*
+ * Do the hard work of removing an element from the buddy allocator.
+ * Call me with the zone->lock already held.
+ */
+static struct page *__rmqueue(struct zone *zone, unsigned int order,
+ int migratetype)
+{
+ struct page *page;
+
+retry_reserve:
+ page = __rmqueue_smallest(zone, order, migratetype);
+
+ if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
+ if (migratetype == MIGRATE_MOVABLE)
+ page = __rmqueue_cma_fallback(zone, order);
+
+ if (!page)
+ page = __rmqueue_fallback(zone, order, migratetype);
+
+ /*
+ * Use MIGRATE_RESERVE rather than fail an allocation. goto
+ * is used because __rmqueue_smallest is an inline function
+ * and we want just one call site
+ */
+ if (!page) {
+ migratetype = MIGRATE_RESERVE;
+ goto retry_reserve;
+ }
+ }
+
+ 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, bool cold)
+{
+ int i;
+
+ spin_lock(&zone->lock);
+ for (i = 0; i < count; ++i) {
+ struct page *page = __rmqueue(zone, order, migratetype);
+ if (unlikely(page == NULL))
+ break;
+
+ /*
+ * Split buddy pages returned by expand() are received here
+ * in physical page order. The page is added to the callers and
+ * list and the list head then moves forward. From the callers
+ * perspective, the linked list is ordered by page number in
+ * some conditions. This is useful for IO devices that can
+ * merge IO requests if the physical pages are ordered
+ * properly.
+ */
+ if (likely(!cold))
+ list_add(&page->lru, list);
+ else
+ list_add_tail(&page->lru, list);
+ list = &page->lru;
+ if (is_migrate_cma(get_freepage_migratetype(page)))
+ __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
+ -(1 << order));
+ }
+ __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
+ spin_unlock(&zone->lock);
+ return i;
+}
+
+#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;
+ LIST_HEAD(dst);
+ int to_drain, batch;
+
+ local_lock_irqsave(pa_lock, flags);
+ batch = READ_ONCE(pcp->batch);
+ to_drain = min(pcp->count, batch);
+ if (to_drain > 0) {
+ isolate_pcp_pages(to_drain, pcp, &dst);
+ pcp->count -= to_drain;
+ }
+ local_unlock_irqrestore(pa_lock, flags);
+ free_pcppages_bulk(zone, to_drain, &dst);
+}
+#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;
+ LIST_HEAD(dst);
+ int count;
+
+ cpu_lock_irqsave(cpu, flags);
+ pset = per_cpu_ptr(zone->pageset, cpu);
+
+ pcp = &pset->pcp;
+ count = pcp->count;
+ if (count) {
+ isolate_pcp_pages(count, pcp, &dst);
+ pcp->count = 0;
+ }
+ cpu_unlock_irqrestore(cpu, flags);
+ if (count)
+ free_pcppages_bulk(zone, count, &dst);
+}
+
+/*
+ * 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);
+}
+
+/*
+ * 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 code is protected against sending an IPI to an offline
+ * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
+ * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
+ * nothing keeps CPUs from showing up after we populated the cpumask and
+ * before the call to on_each_cpu_mask().
+ */
+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;
+
+ /*
+ * 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);
+ }
+#ifndef CONFIG_PREEMPT_RT_BASE
+ on_each_cpu_mask(&cpus_with_pcps, (smp_call_func_t) drain_local_pages,
+ zone, 1);
+#else
+ for_each_cpu(cpu, &cpus_with_pcps) {
+ if (zone)
+ drain_pages_zone(cpu, zone);
+ else
+ drain_pages(cpu);
+ }
+#endif
+}
+
+#ifdef CONFIG_HIBERNATION
+
+void mark_free_pages(struct zone *zone)
+{
+ unsigned long pfn, max_zone_pfn;
+ unsigned long flags;
+ unsigned int order, t;
+ struct list_head *curr;
+
+ 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)) {
+ struct page *page = pfn_to_page(pfn);
+
+ if (!swsusp_page_is_forbidden(page))
+ swsusp_unset_page_free(page);
+ }
+
+ for_each_migratetype_order(order, t) {
+ list_for_each(curr, &zone->free_area[order].free_list[t]) {
+ unsigned long i;
+
+ pfn = page_to_pfn(list_entry(curr, struct page, lru));
+ for (i = 0; i < (1UL << order); i++)
+ swsusp_set_page_free(pfn_to_page(pfn + i));
+ }
+ }
+ spin_unlock_irqrestore(&zone->lock, flags);
+}
+#endif /* CONFIG_PM */
+
+/*
+ * Free a 0-order page
+ * cold == true ? free a cold page : free a hot page
+ */
+void free_hot_cold_page(struct page *page, bool cold)
+{
+ struct zone *zone = page_zone(page);
+ struct per_cpu_pages *pcp;
+ unsigned long flags;
+ unsigned long pfn = page_to_pfn(page);
+ int migratetype;
+
+ if (!free_pages_prepare(page, 0))
+ return;
+
+ migratetype = get_pfnblock_migratetype(page, pfn);
+ set_freepage_migratetype(page, migratetype);
+ local_lock_irqsave(pa_lock, flags);
+ __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 RESERVE 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);
+ goto out;
+ }
+ migratetype = MIGRATE_MOVABLE;
+ }
+
+ pcp = &this_cpu_ptr(zone->pageset)->pcp;
+ if (!cold)
+ list_add(&page->lru, &pcp->lists[migratetype]);
+ else
+ list_add_tail(&page->lru, &pcp->lists[migratetype]);
+ pcp->count++;
+ if (pcp->count >= pcp->high) {
+ unsigned long batch = READ_ONCE(pcp->batch);
+ LIST_HEAD(dst);
+
+ isolate_pcp_pages(batch, pcp, &dst);
+ pcp->count -= batch;
+ local_unlock_irqrestore(pa_lock, flags);
+ free_pcppages_bulk(zone, batch, &dst);
+ return;
+ }
+
+out:
+ local_unlock_irqrestore(pa_lock, flags);
+}
+
+/*
+ * Free a list of 0-order pages
+ */
+void free_hot_cold_page_list(struct list_head *list, bool cold)
+{
+ struct page *page, *next;
+
+ list_for_each_entry_safe(page, next, list, lru) {
+ trace_mm_page_free_batched(page, cold);
+ free_hot_cold_page(page, cold);
+ }
+}
+
+/*
+ * 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);
+
+#ifdef CONFIG_KMEMCHECK
+ /*
+ * Split shadow pages too, because free(page[0]) would
+ * otherwise free the whole shadow.
+ */
+ if (kmemcheck_page_is_tracked(page))
+ split_page(virt_to_page(page[0].shadow), order);
+#endif
+
+ set_page_owner(page, 0, 0);
+ for (i = 1; i < (1 << order); i++) {
+ set_page_refcounted(page + i);
+ set_page_owner(page + i, 0, 0);
+ }
+}
+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 */
+ watermark = low_wmark_pages(zone) + (1 << order);
+ if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
+ 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 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))
+ set_pageblock_migratetype(page,
+ MIGRATE_MOVABLE);
+ }
+ }
+
+ set_page_owner(page, order, 0);
+ return 1UL << order;
+}
+
+/*
+ * Similar to split_page except the page is already free. As this is only
+ * being used for migration, the migratetype of the block also changes.
+ * As this is called with interrupts disabled, the caller is responsible
+ * for calling arch_alloc_page() and kernel_map_page() after interrupts
+ * are enabled.
+ *
+ * Note: this is probably too low level an operation for use in drivers.
+ * Please consult with lkml before using this in your driver.
+ */
+int split_free_page(struct page *page)
+{
+ unsigned int order;
+ int nr_pages;
+
+ order = page_order(page);
+
+ nr_pages = __isolate_free_page(page, order);
+ if (!nr_pages)
+ return 0;
+
+ /* Split into individual pages */
+ set_page_refcounted(page);
+ split_page(page, order);
+ return nr_pages;
+}
+
+/*
+ * Allocate a page from the given zone. Use pcplists for order-0 allocations.
+ */
+static inline
+struct page *buffered_rmqueue(struct zone *preferred_zone,
+ struct zone *zone, unsigned int order,
+ gfp_t gfp_flags, int migratetype)
+{
+ unsigned long flags;
+ struct page *page;
+ bool cold = ((gfp_flags & __GFP_COLD) != 0);
+
+ if (likely(order == 0)) {
+ struct per_cpu_pages *pcp;
+ struct list_head *list;
+
+ local_lock_irqsave(pa_lock, flags);
+ pcp = &this_cpu_ptr(zone->pageset)->pcp;
+ list = &pcp->lists[migratetype];
+ if (list_empty(list)) {
+ pcp->count += rmqueue_bulk(zone, 0,
+ pcp->batch, list,
+ migratetype, cold);
+ if (unlikely(list_empty(list)))
+ goto failed;
+ }
+
+ if (cold)
+ page = list_entry(list->prev, struct page, lru);
+ else
+ page = list_entry(list->next, struct page, lru);
+
+ list_del(&page->lru);
+ pcp->count--;
+ } else {
+ if (unlikely(gfp_flags & __GFP_NOFAIL)) {
+ /*
+ * __GFP_NOFAIL is not to be used in new code.
+ *
+ * All __GFP_NOFAIL callers should be fixed so that they
+ * properly detect and handle allocation failures.
+ *
+ * We most definitely don't want callers attempting to
+ * allocate greater than order-1 page units with
+ * __GFP_NOFAIL.
+ */
+ WARN_ON_ONCE(order > 1);
+ }
+ local_spin_lock_irqsave(pa_lock, &zone->lock, flags);
+ page = __rmqueue(zone, order, migratetype);
+ if (!page) {
+ spin_unlock(&zone->lock);
+ goto failed;
+ }
+ __mod_zone_freepage_state(zone, -(1 << order),
+ get_freepage_migratetype(page));
+ spin_unlock(&zone->lock);
+ }
+
+ __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
+ if (atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]) <= 0 &&
+ !test_bit(ZONE_FAIR_DEPLETED, &zone->flags))
+ set_bit(ZONE_FAIR_DEPLETED, &zone->flags);
+
+ __count_zone_vm_events(PGALLOC, zone, 1 << order);
+ zone_statistics(preferred_zone, zone, gfp_flags);
+ local_unlock_irqrestore(pa_lock, flags);
+
+ VM_BUG_ON_PAGE(bad_range(zone, page), page);
+ return page;
+
+failed:
+ local_unlock_irqrestore(pa_lock, flags);
+ return NULL;
+}
+
+#ifdef CONFIG_FAIL_PAGE_ALLOC
+
+static struct {
+ struct fault_attr attr;
+
+ u32 ignore_gfp_highmem;
+ u32 ignore_gfp_wait;
+ u32 min_order;
+} fail_page_alloc = {
+ .attr = FAULT_ATTR_INITIALIZER,
+ .ignore_gfp_wait = 1,
+ .ignore_gfp_highmem = 1,
+ .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_wait && (gfp_mask & __GFP_WAIT))
+ 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 | S_IRUSR | S_IWUSR;
+ 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_wait))
+ 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 pages are above 'mark'. This takes into account the order
+ * of the allocation.
+ */
+static bool __zone_watermark_ok(struct zone *z, unsigned int order,
+ unsigned long mark, int classzone_idx, int alloc_flags,
+ long free_pages)
+{
+ /* free_pages may go negative - that's OK */
+ long min = mark;
+ int o;
+ long free_cma = 0;
+
+ free_pages -= (1 << order) - 1;
+ if (alloc_flags & ALLOC_HIGH)
+ min -= min / 2;
+ if (alloc_flags & ALLOC_HARDER)
+ 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_cma = zone_page_state(z, NR_FREE_CMA_PAGES);
+#endif
+
+ if (free_pages - free_cma <= min + z->lowmem_reserve[classzone_idx])
+ return false;
+ for (o = 0; o < order; o++) {
+ /* At the next order, this order's pages become unavailable */
+ free_pages -= z->free_area[o].nr_free << o;
+
+ /* Require fewer higher order pages to be free */
+ min >>= 1;
+
+ if (free_pages <= min)
+ return false;
+ }
+ return true;
+}
+
+bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
+ int classzone_idx, int alloc_flags)
+{
+ return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
+ zone_page_state(z, NR_FREE_PAGES));
+}
+
+bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
+ unsigned long mark, int classzone_idx, int alloc_flags)
+{
+ 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, alloc_flags,
+ free_pages);
+}
+
+#ifdef CONFIG_NUMA
+/*
+ * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
+ * skip over zones that are not allowed by the cpuset, or that have
+ * been recently (in last second) found to be nearly full. See further
+ * comments in mmzone.h. Reduces cache footprint of zonelist scans
+ * that have to skip over a lot of full or unallowed zones.
+ *
+ * If the zonelist cache is present in the passed zonelist, then
+ * returns a pointer to the allowed node mask (either the current
+ * tasks mems_allowed, or node_states[N_MEMORY].)
+ *
+ * If the zonelist cache is not available for this zonelist, does
+ * nothing and returns NULL.
+ *
+ * If the fullzones BITMAP in the zonelist cache is stale (more than
+ * a second since last zap'd) then we zap it out (clear its bits.)
+ *
+ * We hold off even calling zlc_setup, until after we've checked the
+ * first zone in the zonelist, on the theory that most allocations will
+ * be satisfied from that first zone, so best to examine that zone as
+ * quickly as we can.
+ */
+static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
+{
+ struct zonelist_cache *zlc; /* cached zonelist speedup info */
+ nodemask_t *allowednodes; /* zonelist_cache approximation */
+
+ zlc = zonelist->zlcache_ptr;
+ if (!zlc)
+ return NULL;
+
+ if (time_after(jiffies, zlc->last_full_zap + HZ)) {
+ bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
+ zlc->last_full_zap = jiffies;
+ }
+
+ allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
+ &cpuset_current_mems_allowed :
+ &node_states[N_MEMORY];
+ return allowednodes;
+}
+
+/*
+ * Given 'z' scanning a zonelist, run a couple of quick checks to see
+ * if it is worth looking at further for free memory:
+ * 1) Check that the zone isn't thought to be full (doesn't have its
+ * bit set in the zonelist_cache fullzones BITMAP).
+ * 2) Check that the zones node (obtained from the zonelist_cache
+ * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
+ * Return true (non-zero) if zone is worth looking at further, or
+ * else return false (zero) if it is not.
+ *
+ * This check -ignores- the distinction between various watermarks,
+ * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
+ * found to be full for any variation of these watermarks, it will
+ * be considered full for up to one second by all requests, unless
+ * we are so low on memory on all allowed nodes that we are forced
+ * into the second scan of the zonelist.
+ *
+ * In the second scan we ignore this zonelist cache and exactly
+ * apply the watermarks to all zones, even it is slower to do so.
+ * We are low on memory in the second scan, and should leave no stone
+ * unturned looking for a free page.
+ */
+static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
+ nodemask_t *allowednodes)
+{
+ struct zonelist_cache *zlc; /* cached zonelist speedup info */
+ int i; /* index of *z in zonelist zones */
+ int n; /* node that zone *z is on */
+
+ zlc = zonelist->zlcache_ptr;
+ if (!zlc)
+ return 1;
+
+ i = z - zonelist->_zonerefs;
+ n = zlc->z_to_n[i];
+
+ /* This zone is worth trying if it is allowed but not full */
+ return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones);
+}
+
+/*
+ * Given 'z' scanning a zonelist, set the corresponding bit in
+ * zlc->fullzones, so that subsequent attempts to allocate a page
+ * from that zone don't waste time re-examining it.
+ */
+static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
+{
+ struct zonelist_cache *zlc; /* cached zonelist speedup info */
+ int i; /* index of *z in zonelist zones */
+
+ zlc = zonelist->zlcache_ptr;
+ if (!zlc)
+ return;
+
+ i = z - zonelist->_zonerefs;
+
+ set_bit(i, zlc->fullzones);
+}
+
+/*
+ * clear all zones full, called after direct reclaim makes progress so that
+ * a zone that was recently full is not skipped over for up to a second
+ */
+static void zlc_clear_zones_full(struct zonelist *zonelist)
+{
+ struct zonelist_cache *zlc; /* cached zonelist speedup info */
+
+ zlc = zonelist->zlcache_ptr;
+ if (!zlc)
+ return;
+
+ bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
+}
+
+static bool zone_local(struct zone *local_zone, struct zone *zone)
+{
+ return local_zone->node == zone->node;
+}
+
+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 nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
+{
+ return NULL;
+}
+
+static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
+ nodemask_t *allowednodes)
+{
+ return 1;
+}
+
+static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
+{
+}
+
+static void zlc_clear_zones_full(struct zonelist *zonelist)
+{
+}
+
+static bool zone_local(struct zone *local_zone, struct zone *zone)
+{
+ return true;
+}
+
+static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
+{
+ return true;
+}
+
+#endif /* CONFIG_NUMA */
+
+static void reset_alloc_batches(struct zone *preferred_zone)
+{
+ struct zone *zone = preferred_zone->zone_pgdat->node_zones;
+
+ do {
+ mod_zone_page_state(zone, NR_ALLOC_BATCH,
+ high_wmark_pages(zone) - low_wmark_pages(zone) -
+ atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
+ clear_bit(ZONE_FAIR_DEPLETED, &zone->flags);
+ } while (zone++ != preferred_zone);
+}
+
+/*
+ * 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 zonelist *zonelist = ac->zonelist;
+ struct zoneref *z;
+ struct page *page = NULL;
+ struct zone *zone;
+ nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */
+ int zlc_active = 0; /* set if using zonelist_cache */
+ int did_zlc_setup = 0; /* just call zlc_setup() one time */
+ bool consider_zone_dirty = (alloc_flags & ALLOC_WMARK_LOW) &&
+ (gfp_mask & __GFP_WRITE);
+ int nr_fair_skipped = 0;
+ bool zonelist_rescan;
+
+zonelist_scan:
+ zonelist_rescan = false;
+
+ /*
+ * Scan zonelist, looking for a zone with enough free.
+ * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
+ */
+ for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx,
+ ac->nodemask) {
+ unsigned long mark;
+
+ if (IS_ENABLED(CONFIG_NUMA) && zlc_active &&
+ !zlc_zone_worth_trying(zonelist, z, allowednodes))
+ continue;
+ if (cpusets_enabled() &&
+ (alloc_flags & ALLOC_CPUSET) &&
+ !cpuset_zone_allowed(zone, gfp_mask))
+ continue;
+ /*
+ * Distribute pages in proportion to the individual
+ * zone size to ensure fair page aging. The zone a
+ * page was allocated in should have no effect on the
+ * time the page has in memory before being reclaimed.
+ */
+ if (alloc_flags & ALLOC_FAIR) {
+ if (!zone_local(ac->preferred_zone, zone))
+ break;
+ if (test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) {
+ nr_fair_skipped++;
+ continue;
+ }
+ }
+ /*
+ * When allocating a page cache page for writing, we
+ * want to get it from a zone that is within its dirty
+ * limit, such that no single zone holds more than its
+ * proportional share of globally allowed dirty pages.
+ * The dirty limits take into account the zone's
+ * lowmem reserves and high watermark so that kswapd
+ * should be able to balance it without having to
+ * write pages from its LRU list.
+ *
+ * This may look like it could increase pressure on
+ * lower zones by failing allocations in higher zones
+ * before they are full. But the pages that do spill
+ * over are limited as the lower zones are protected
+ * by this very same mechanism. It should not become
+ * a practical burden to them.
+ *
+ * XXX: For now, allow allocations to potentially
+ * exceed the per-zone dirty limit in the slowpath
+ * (ALLOC_WMARK_LOW unset) before going into reclaim,
+ * which is important when on a NUMA setup the allowed
+ * zones are together not big enough to reach the
+ * global limit. The proper fix for these situations
+ * will require awareness of zones in the
+ * dirty-throttling and the flusher threads.
+ */
+ if (consider_zone_dirty && !zone_dirty_ok(zone))
+ continue;
+
+ mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
+ if (!zone_watermark_ok(zone, order, mark,
+ ac->classzone_idx, alloc_flags)) {
+ int ret;
+
+ /* 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 (IS_ENABLED(CONFIG_NUMA) &&
+ !did_zlc_setup && nr_online_nodes > 1) {
+ /*
+ * we do zlc_setup if there are multiple nodes
+ * and before considering the first zone allowed
+ * by the cpuset.
+ */
+ allowednodes = zlc_setup(zonelist, alloc_flags);
+ zlc_active = 1;
+ did_zlc_setup = 1;
+ }
+
+ if (zone_reclaim_mode == 0 ||
+ !zone_allows_reclaim(ac->preferred_zone, zone))
+ goto this_zone_full;
+
+ /*
+ * As we may have just activated ZLC, check if the first
+ * eligible zone has failed zone_reclaim recently.
+ */
+ if (IS_ENABLED(CONFIG_NUMA) && zlc_active &&
+ !zlc_zone_worth_trying(zonelist, z, allowednodes))
+ continue;
+
+ ret = zone_reclaim(zone, gfp_mask, order);
+ switch (ret) {
+ case ZONE_RECLAIM_NOSCAN:
+ /* did not scan */
+ continue;
+ case ZONE_RECLAIM_FULL:
+ /* scanned but unreclaimable */
+ continue;
+ default:
+ /* did we reclaim enough */
+ if (zone_watermark_ok(zone, order, mark,
+ ac->classzone_idx, alloc_flags))
+ goto try_this_zone;
+
+ /*
+ * Failed to reclaim enough to meet watermark.
+ * Only mark the zone full if checking the min
+ * watermark or if we failed to reclaim just
+ * 1<<order pages or else the page allocator
+ * fastpath will prematurely mark zones full
+ * when the watermark is between the low and
+ * min watermarks.
+ */
+ if (((alloc_flags & ALLOC_WMARK_MASK) == ALLOC_WMARK_MIN) ||
+ ret == ZONE_RECLAIM_SOME)
+ goto this_zone_full;
+
+ continue;
+ }
+ }
+
+try_this_zone:
+ page = buffered_rmqueue(ac->preferred_zone, zone, order,
+ gfp_mask, ac->migratetype);
+ if (page) {
+ if (prep_new_page(page, order, gfp_mask, alloc_flags))
+ goto try_this_zone;
+ return page;
+ }
+this_zone_full:
+ if (IS_ENABLED(CONFIG_NUMA) && zlc_active)
+ zlc_mark_zone_full(zonelist, z);
+ }
+
+ /*
+ * The first pass makes sure allocations are spread fairly within the
+ * local node. However, the local node might have free pages left
+ * after the fairness batches are exhausted, and remote zones haven't
+ * even been considered yet. Try once more without fairness, and
+ * include remote zones now, before entering the slowpath and waking
+ * kswapd: prefer spilling to a remote zone over swapping locally.
+ */
+ if (alloc_flags & ALLOC_FAIR) {
+ alloc_flags &= ~ALLOC_FAIR;
+ if (nr_fair_skipped) {
+ zonelist_rescan = true;
+ reset_alloc_batches(ac->preferred_zone);
+ }
+ if (nr_online_nodes > 1)
+ zonelist_rescan = true;
+ }
+
+ if (unlikely(IS_ENABLED(CONFIG_NUMA) && zlc_active)) {
+ /* Disable zlc cache for second zonelist scan */
+ zlc_active = 0;
+ zonelist_rescan = true;
+ }
+
+ if (zonelist_rescan)
+ goto zonelist_scan;
+
+ 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 DEFINE_RATELIMIT_STATE(nopage_rs,
+ DEFAULT_RATELIMIT_INTERVAL,
+ DEFAULT_RATELIMIT_BURST);
+
+void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...)
+{
+ unsigned int filter = SHOW_MEM_FILTER_NODES;
+
+ if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
+ debug_guardpage_minorder() > 0)
+ 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 (test_thread_flag(TIF_MEMDIE) ||
+ (current->flags & (PF_MEMALLOC | PF_EXITING)))
+ filter &= ~SHOW_MEM_FILTER_NODES;
+ if (in_interrupt() || !(gfp_mask & __GFP_WAIT))
+ filter &= ~SHOW_MEM_FILTER_NODES;
+
+ if (fmt) {
+ struct va_format vaf;
+ va_list args;
+
+ va_start(args, fmt);
+
+ vaf.fmt = fmt;
+ vaf.va = &args;
+
+ pr_warn("%pV", &vaf);
+
+ va_end(args);
+ }
+
+ pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
+ current->comm, order, gfp_mask);
+
+ dump_stack();
+ if (!should_suppress_show_mem())
+ show_mem(filter);
+}
+
+static inline int
+should_alloc_retry(gfp_t gfp_mask, unsigned int order,
+ unsigned long did_some_progress,
+ unsigned long pages_reclaimed)
+{
+ /* Do not loop if specifically requested */
+ if (gfp_mask & __GFP_NORETRY)
+ return 0;
+
+ /* Always retry if specifically requested */
+ if (gfp_mask & __GFP_NOFAIL)
+ return 1;
+
+ /*
+ * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
+ * making forward progress without invoking OOM. Suspend also disables
+ * storage devices so kswapd will not help. Bail if we are suspending.
+ */
+ if (!did_some_progress && pm_suspended_storage())
+ return 0;
+
+ /*
+ * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
+ * means __GFP_NOFAIL, but that may not be true in other
+ * implementations.
+ */
+ if (order <= PAGE_ALLOC_COSTLY_ORDER)
+ return 1;
+
+ /*
+ * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
+ * specified, then we retry until we no longer reclaim any pages
+ * (above), or we've reclaimed an order of pages at least as
+ * large as the allocation's order. In both cases, if the
+ * allocation still fails, we stop retrying.
+ */
+ if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order))
+ return 1;
+
+ return 0;
+}
+
+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 page *page;
+
+ *did_some_progress = 0;
+
+ /*
+ * Acquire the per-zone oom lock for each zone. If that
+ * fails, somebody else is making progress for us.
+ */
+ if (!oom_zonelist_trylock(ac->zonelist, gfp_mask)) {
+ *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.
+ */
+ page = get_page_from_freelist(gfp_mask | __GFP_HARDWALL, order,
+ ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
+ if (page)
+ goto out;
+
+ if (!(gfp_mask & __GFP_NOFAIL)) {
+ /* 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;
+ /* The OOM killer does not needlessly kill tasks for lowmem */
+ if (ac->high_zoneidx < ZONE_NORMAL)
+ goto out;
+ /* The OOM killer does not compensate for light reclaim */
+ if (!(gfp_mask & __GFP_FS)) {
+ /*
+ * XXX: Page reclaim didn't yield anything,
+ * and the OOM killer can't be invoked, but
+ * keep looping as per should_alloc_retry().
+ */
+ *did_some_progress = 1;
+ goto out;
+ }
+ /* 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 blamo time */
+ if (out_of_memory(ac->zonelist, gfp_mask, order, ac->nodemask, false)
+ || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL))
+ *did_some_progress = 1;
+out:
+ oom_zonelist_unlock(ac->zonelist, gfp_mask);
+ return page;
+}
+
+#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,
+ int alloc_flags, const struct alloc_context *ac,
+ enum migrate_mode mode, int *contended_compaction,
+ bool *deferred_compaction)
+{
+ unsigned long compact_result;
+ struct page *page;
+
+ if (!order)
+ return NULL;
+
+ current->flags |= PF_MEMALLOC;
+ compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
+ mode, contended_compaction);
+ current->flags &= ~PF_MEMALLOC;
+
+ switch (compact_result) {
+ case COMPACT_DEFERRED:
+ *deferred_compaction = true;
+ /* fall-through */
+ case COMPACT_SKIPPED:
+ return NULL;
+ default:
+ break;
+ }
+
+ /*
+ * 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 & ~ALLOC_NO_WATERMARKS, 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;
+}
+#else
+static inline struct page *
+__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
+ int alloc_flags, const struct alloc_context *ac,
+ enum migrate_mode mode, int *contended_compaction,
+ bool *deferred_compaction)
+{
+ return NULL;
+}
+#endif /* CONFIG_COMPACTION */
+
+/* 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;
+
+ cond_resched();
+
+ /* We now go into synchronous reclaim */
+ cpuset_memory_pressure_bump();
+ current->flags |= PF_MEMALLOC;
+ lockdep_set_current_reclaim_state(gfp_mask);
+ 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;
+ lockdep_clear_current_reclaim_state();
+ current->flags &= ~PF_MEMALLOC;
+
+ 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,
+ 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;
+
+ /* After successful reclaim, reconsider all zones for allocation */
+ if (IS_ENABLED(CONFIG_NUMA))
+ zlc_clear_zones_full(ac->zonelist);
+
+retry:
+ page = get_page_from_freelist(gfp_mask, order,
+ alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
+
+ /*
+ * If an allocation failed after direct reclaim, it could be because
+ * pages are pinned on the per-cpu lists. Drain them and try again
+ */
+ if (!page && !drained) {
+ drain_all_pages(NULL);
+ drained = true;
+ goto retry;
+ }
+
+ return page;
+}
+
+/*
+ * This is called in the allocator slow-path if the allocation request is of
+ * sufficient urgency to ignore watermarks and take other desperate measures
+ */
+static inline struct page *
+__alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
+ const struct alloc_context *ac)
+{
+ struct page *page;
+
+ do {
+ page = get_page_from_freelist(gfp_mask, order,
+ ALLOC_NO_WATERMARKS, ac);
+
+ if (!page && gfp_mask & __GFP_NOFAIL)
+ wait_iff_congested(ac->preferred_zone, BLK_RW_ASYNC,
+ HZ/50);
+ } while (!page && (gfp_mask & __GFP_NOFAIL));
+
+ return page;
+}
+
+static void wake_all_kswapds(unsigned int order, const struct alloc_context *ac)
+{
+ struct zoneref *z;
+ struct zone *zone;
+
+ for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
+ ac->high_zoneidx, ac->nodemask)
+ wakeup_kswapd(zone, order, zone_idx(ac->preferred_zone));
+}
+
+static inline int
+gfp_to_alloc_flags(gfp_t gfp_mask)
+{
+ int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
+ const bool atomic = !(gfp_mask & (__GFP_WAIT | __GFP_NO_KSWAPD));
+
+ /* __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 (atomic == true) and ALLOC_HIGH (__GFP_HIGH).
+ */
+ alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
+
+ if (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;
+
+ if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
+ if (gfp_mask & __GFP_MEMALLOC)
+ alloc_flags |= ALLOC_NO_WATERMARKS;
+ else if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
+ alloc_flags |= ALLOC_NO_WATERMARKS;
+ else if (!in_interrupt() &&
+ ((current->flags & PF_MEMALLOC) ||
+ unlikely(test_thread_flag(TIF_MEMDIE))))
+ alloc_flags |= ALLOC_NO_WATERMARKS;
+ }
+#ifdef CONFIG_CMA
+ if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
+ alloc_flags |= ALLOC_CMA;
+#endif
+ return alloc_flags;
+}
+
+bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
+{
+ return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS);
+}
+
+static inline struct page *
+__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
+ struct alloc_context *ac)
+{
+ const gfp_t wait = gfp_mask & __GFP_WAIT;
+ struct page *page = NULL;
+ int alloc_flags;
+ unsigned long pages_reclaimed = 0;
+ unsigned long did_some_progress;
+ enum migrate_mode migration_mode = MIGRATE_ASYNC;
+ bool deferred_compaction = false;
+ int contended_compaction = COMPACT_CONTENDED_NONE;
+
+ /*
+ * In the slowpath, we sanity check order to avoid ever trying to
+ * reclaim >= MAX_ORDER areas which will never succeed. Callers may
+ * be using allocators in order of preference for an area that is
+ * too large.
+ */
+ if (order >= MAX_ORDER) {
+ WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
+ return NULL;
+ }
+
+ /*
+ * If this allocation cannot block and it is for a specific node, then
+ * fail early. There's no need to wakeup kswapd or retry for a
+ * speculative node-specific allocation.
+ */
+ if (IS_ENABLED(CONFIG_NUMA) && (gfp_mask & __GFP_THISNODE) && !wait)
+ goto nopage;
+
+retry:
+ if (!(gfp_mask & __GFP_NO_KSWAPD))
+ wake_all_kswapds(order, ac);
+
+ /*
+ * OK, we're below the kswapd watermark and have kicked background
+ * reclaim. Now things get more complex, so set up alloc_flags according
+ * to how we want to proceed.
+ */
+ alloc_flags = gfp_to_alloc_flags(gfp_mask);
+
+ /*
+ * Find the true preferred zone if the allocation is unconstrained by
+ * cpusets.
+ */
+ if (!(alloc_flags & ALLOC_CPUSET) && !ac->nodemask) {
+ struct zoneref *preferred_zoneref;
+ preferred_zoneref = first_zones_zonelist(ac->zonelist,
+ ac->high_zoneidx, NULL, &ac->preferred_zone);
+ ac->classzone_idx = zonelist_zone_idx(preferred_zoneref);
+ }
+
+ /* This is the last chance, in general, before the goto nopage. */
+ page = get_page_from_freelist(gfp_mask, order,
+ alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
+ if (page)
+ goto got_pg;
+
+ /* Allocate without watermarks if the context allows */
+ if (alloc_flags & ALLOC_NO_WATERMARKS) {
+ /*
+ * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
+ * the allocation is high priority and these type of
+ * allocations are system rather than user orientated
+ */
+ ac->zonelist = node_zonelist(numa_node_id(), gfp_mask);
+
+ page = __alloc_pages_high_priority(gfp_mask, order, ac);
+
+ if (page) {
+ goto got_pg;
+ }
+ }
+
+ /* Atomic allocations - we can't balance anything */
+ if (!wait) {
+ /*
+ * All existing users of the deprecated __GFP_NOFAIL are
+ * blockable, so warn of any new users that actually allow this
+ * type of allocation to fail.
+ */
+ WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL);
+ goto nopage;
+ }
+
+ /* Avoid recursion of direct reclaim */
+ if (current->flags & PF_MEMALLOC)
+ goto nopage;
+
+ /* Avoid allocations with no watermarks from looping endlessly */
+ if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
+ goto nopage;
+
+ /*
+ * Try direct compaction. The first pass is asynchronous. Subsequent
+ * attempts after direct reclaim are synchronous
+ */
+ page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac,
+ migration_mode,
+ &contended_compaction,
+ &deferred_compaction);
+ if (page)
+ goto got_pg;
+
+ /* Checks for THP-specific high-order allocations */
+ if ((gfp_mask & GFP_TRANSHUGE) == GFP_TRANSHUGE) {
+ /*
+ * 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 (deferred_compaction)
+ goto nopage;
+
+ /*
+ * In all zones where compaction was attempted (and not
+ * deferred or skipped), lock contention has been detected.
+ * For THP allocation we do not want to disrupt the others
+ * so we fallback to base pages instead.
+ */
+ if (contended_compaction == COMPACT_CONTENDED_LOCK)
+ goto nopage;
+
+ /*
+ * If compaction was aborted due to need_resched(), we do not
+ * want to further increase allocation latency, unless it is
+ * khugepaged trying to collapse.
+ */
+ if (contended_compaction == COMPACT_CONTENDED_SCHED
+ && !(current->flags & PF_KTHREAD))
+ goto nopage;
+ }
+
+ /*
+ * It can become very expensive to allocate transparent hugepages at
+ * fault, so use asynchronous memory compaction for THP unless it is
+ * khugepaged trying to collapse.
+ */
+ if ((gfp_mask & GFP_TRANSHUGE) != GFP_TRANSHUGE ||
+ (current->flags & PF_KTHREAD))
+ migration_mode = MIGRATE_SYNC_LIGHT;
+
+ /* 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;
+
+ /* Check if we should retry the allocation */
+ pages_reclaimed += did_some_progress;
+ if (should_alloc_retry(gfp_mask, order, did_some_progress,
+ pages_reclaimed)) {
+ /*
+ * If we fail to make progress by freeing individual
+ * pages, but the allocation wants us to keep going,
+ * start OOM killing tasks.
+ */
+ if (!did_some_progress) {
+ page = __alloc_pages_may_oom(gfp_mask, order, ac,
+ &did_some_progress);
+ if (page)
+ goto got_pg;
+ if (!did_some_progress)
+ goto nopage;
+ }
+ /* Wait for some write requests to complete then retry */
+ wait_iff_congested(ac->preferred_zone, BLK_RW_ASYNC, HZ/50);
+ goto retry;
+ } else {
+ /*
+ * High-order allocations do not necessarily loop after
+ * direct reclaim and reclaim/compaction depends on compaction
+ * being called after reclaim so call directly if necessary
+ */
+ page = __alloc_pages_direct_compact(gfp_mask, order,
+ alloc_flags, ac, migration_mode,
+ &contended_compaction,
+ &deferred_compaction);
+ if (page)
+ goto got_pg;
+ }
+
+nopage:
+ warn_alloc_failed(gfp_mask, order, NULL);
+got_pg:
+ return page;
+}
+
+/*
+ * This is the 'heart' of the zoned buddy allocator.
+ */
+struct page *
+__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
+ struct zonelist *zonelist, nodemask_t *nodemask)
+{
+ struct zoneref *preferred_zoneref;
+ struct page *page = NULL;
+ unsigned int cpuset_mems_cookie;
+ int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET|ALLOC_FAIR;
+ gfp_t alloc_mask; /* The gfp_t that was actually used for allocation */
+ struct alloc_context ac = {
+ .high_zoneidx = gfp_zone(gfp_mask),
+ .nodemask = nodemask,
+ .migratetype = gfpflags_to_migratetype(gfp_mask),
+ };
+
+ gfp_mask &= gfp_allowed_mask;
+
+ lockdep_trace_alloc(gfp_mask);
+
+ might_sleep_if(gfp_mask & __GFP_WAIT);
+
+ if (should_fail_alloc_page(gfp_mask, order))
+ return NULL;
+
+ /*
+ * Check the zones suitable for the gfp_mask contain at least one
+ * valid zone. It's possible to have an empty zonelist as a result
+ * of __GFP_THISNODE and a memoryless node
+ */
+ if (unlikely(!zonelist->_zonerefs->zone))
+ return NULL;
+
+ if (IS_ENABLED(CONFIG_CMA) && ac.migratetype == MIGRATE_MOVABLE)
+ alloc_flags |= ALLOC_CMA;
+
+retry_cpuset:
+ cpuset_mems_cookie = read_mems_allowed_begin();
+
+ /* We set it here, as __alloc_pages_slowpath might have changed it */
+ ac.zonelist = zonelist;
+ /* The preferred zone is used for statistics later */
+ preferred_zoneref = first_zones_zonelist(ac.zonelist, ac.high_zoneidx,
+ ac.nodemask ? : &cpuset_current_mems_allowed,
+ &ac.preferred_zone);
+ if (!ac.preferred_zone)
+ goto out;
+ ac.classzone_idx = zonelist_zone_idx(preferred_zoneref);
+
+ /* First allocation attempt */
+ alloc_mask = gfp_mask|__GFP_HARDWALL;
+ page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);
+ if (unlikely(!page)) {
+ /*
+ * Runtime PM, block IO and its error handling path
+ * can deadlock because I/O on the device might not
+ * complete.
+ */
+ alloc_mask = memalloc_noio_flags(gfp_mask);
+
+ page = __alloc_pages_slowpath(alloc_mask, order, &ac);
+ }
+
+ if (kmemcheck_enabled && page)
+ kmemcheck_pagealloc_alloc(page, order, gfp_mask);
+
+ trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);
+
+out:
+ /*
+ * When updating a task's mems_allowed, it is possible to race with
+ * parallel threads in such a way that an allocation can fail while
+ * the mask is being updated. If a page allocation is about to fail,
+ * check if the cpuset changed during allocation and if so, retry.
+ */
+ if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie)))
+ goto retry_cpuset;
+
+ return page;
+}
+EXPORT_SYMBOL(__alloc_pages_nodemask);
+
+/*
+ * Common helper functions.
+ */
+unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
+{
+ struct page *page;
+
+ /*
+ * __get_free_pages() returns a 32-bit address, which cannot represent
+ * a highmem page
+ */
+ VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
+
+ page = alloc_pages(gfp_mask, 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);
+
+void __free_pages(struct page *page, unsigned int order)
+{
+ if (put_page_testzero(page)) {
+ if (order == 0)
+ free_hot_cold_page(page, false);
+ else
+ __free_pages_ok(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);
+
+/*
+ * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
+ * of the current memory cgroup.
+ *
+ * It should be used when the caller would like to use kmalloc, but since the
+ * allocation is large, it has to fall back to the page allocator.
+ */
+struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order)
+{
+ struct page *page;
+ struct mem_cgroup *memcg = NULL;
+
+ if (!memcg_kmem_newpage_charge(gfp_mask, &memcg, order))
+ return NULL;
+ page = alloc_pages(gfp_mask, order);
+ memcg_kmem_commit_charge(page, memcg, order);
+ return page;
+}
+
+struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
+{
+ struct page *page;
+ struct mem_cgroup *memcg = NULL;
+
+ if (!memcg_kmem_newpage_charge(gfp_mask, &memcg, order))
+ return NULL;
+ page = alloc_pages_node(nid, gfp_mask, order);
+ memcg_kmem_commit_charge(page, memcg, order);
+ return page;
+}
+
+/*
+ * __free_kmem_pages and free_kmem_pages will free pages allocated with
+ * alloc_kmem_pages.
+ */
+void __free_kmem_pages(struct page *page, unsigned int order)
+{
+ memcg_kmem_uncharge_pages(page, order);
+ __free_pages(page, order);
+}
+
+void free_kmem_pages(unsigned long addr, unsigned int order)
+{
+ if (addr != 0) {
+ VM_BUG_ON(!virt_addr_valid((void *)addr));
+ __free_kmem_pages(virt_to_page((void *)addr), order);
+ }
+}
+
+static void *make_alloc_exact(unsigned long addr, unsigned 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.
+ * Note this is not alloc_pages_exact_node() which allocates on a specific node,
+ * but is not exact.
+ */
+void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
+{
+ unsigned 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:
+ * 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));
+}
+
+void si_meminfo(struct sysinfo *val)
+{
+ val->totalram = totalram_pages;
+ val->sharedram = global_page_state(NR_SHMEM);
+ val->freeram = global_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;
+ 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(nid, NR_SHMEM);
+ val->freeram = node_page_state(nid, NR_FREE_PAGES);
+#ifdef CONFIG_HIGHMEM
+ val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].managed_pages;
+ val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
+ NR_FREE_PAGES);
+#else
+ val->totalhigh = 0;
+ val->freehigh = 0;
+#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().
+ */
+bool skip_free_areas_node(unsigned int flags, int nid)
+{
+ bool ret = false;
+ unsigned int cpuset_mems_cookie;
+
+ if (!(flags & SHOW_MEM_FILTER_NODES))
+ goto out;
+
+ do {
+ cpuset_mems_cookie = read_mems_allowed_begin();
+ ret = !node_isset(nid, cpuset_current_mems_allowed);
+ } while (read_mems_allowed_retry(cpuset_mems_cookie));
+out:
+ return ret;
+}
+
+#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_RECLAIMABLE] = 'E',
+ [MIGRATE_MOVABLE] = 'M',
+ [MIGRATE_RESERVE] = 'R',
+#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("(%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)
+{
+ unsigned long free_pcp = 0;
+ int cpu;
+ struct zone *zone;
+
+ for_each_populated_zone(zone) {
+ if (skip_free_areas_node(filter, zone_to_nid(zone)))
+ 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_page_state(NR_ACTIVE_ANON),
+ global_page_state(NR_INACTIVE_ANON),
+ global_page_state(NR_ISOLATED_ANON),
+ global_page_state(NR_ACTIVE_FILE),
+ global_page_state(NR_INACTIVE_FILE),
+ global_page_state(NR_ISOLATED_FILE),
+ global_page_state(NR_UNEVICTABLE),
+ global_page_state(NR_FILE_DIRTY),
+ global_page_state(NR_WRITEBACK),
+ global_page_state(NR_UNSTABLE_NFS),
+ global_page_state(NR_SLAB_RECLAIMABLE),
+ global_page_state(NR_SLAB_UNRECLAIMABLE),
+ global_page_state(NR_FILE_MAPPED),
+ global_page_state(NR_SHMEM),
+ global_page_state(NR_PAGETABLE),
+ global_page_state(NR_BOUNCE),
+ global_page_state(NR_FREE_PAGES),
+ free_pcp,
+ global_page_state(NR_FREE_CMA_PAGES));
+
+ for_each_populated_zone(zone) {
+ int i;
+
+ if (skip_free_areas_node(filter, zone_to_nid(zone)))
+ continue;
+
+ free_pcp = 0;
+ for_each_online_cpu(cpu)
+ free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
+
+ show_node(zone);
+ printk("%s"
+ " free:%lukB"
+ " min:%lukB"
+ " low:%lukB"
+ " high:%lukB"
+ " active_anon:%lukB"
+ " inactive_anon:%lukB"
+ " active_file:%lukB"
+ " inactive_file:%lukB"
+ " unevictable:%lukB"
+ " isolated(anon):%lukB"
+ " isolated(file):%lukB"
+ " present:%lukB"
+ " managed:%lukB"
+ " mlocked:%lukB"
+ " dirty:%lukB"
+ " writeback:%lukB"
+ " mapped:%lukB"
+ " shmem:%lukB"
+ " slab_reclaimable:%lukB"
+ " slab_unreclaimable:%lukB"
+ " kernel_stack:%lukB"
+ " pagetables:%lukB"
+ " unstable:%lukB"
+ " bounce:%lukB"
+ " free_pcp:%lukB"
+ " local_pcp:%ukB"
+ " free_cma:%lukB"
+ " writeback_tmp:%lukB"
+ " pages_scanned:%lu"
+ " all_unreclaimable? %s"
+ "\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_ACTIVE_ANON)),
+ K(zone_page_state(zone, NR_INACTIVE_ANON)),
+ K(zone_page_state(zone, NR_ACTIVE_FILE)),
+ K(zone_page_state(zone, NR_INACTIVE_FILE)),
+ K(zone_page_state(zone, NR_UNEVICTABLE)),
+ K(zone_page_state(zone, NR_ISOLATED_ANON)),
+ K(zone_page_state(zone, NR_ISOLATED_FILE)),
+ K(zone->present_pages),
+ K(zone->managed_pages),
+ K(zone_page_state(zone, NR_MLOCK)),
+ K(zone_page_state(zone, NR_FILE_DIRTY)),
+ K(zone_page_state(zone, NR_WRITEBACK)),
+ K(zone_page_state(zone, NR_FILE_MAPPED)),
+ K(zone_page_state(zone, NR_SHMEM)),
+ K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
+ K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
+ zone_page_state(zone, NR_KERNEL_STACK) *
+ THREAD_SIZE / 1024,
+ K(zone_page_state(zone, NR_PAGETABLE)),
+ K(zone_page_state(zone, NR_UNSTABLE_NFS)),
+ 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)),
+ K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
+ K(zone_page_state(zone, NR_PAGES_SCANNED)),
+ (!zone_reclaimable(zone) ? "yes" : "no")
+ );
+ printk("lowmem_reserve[]:");
+ for (i = 0; i < MAX_NR_ZONES; i++)
+ printk(" %ld", zone->lowmem_reserve[i]);
+ printk("\n");
+ }
+
+ for_each_populated_zone(zone) {
+ unsigned long nr[MAX_ORDER], flags, order, total = 0;
+ unsigned char types[MAX_ORDER];
+
+ if (skip_free_areas_node(filter, zone_to_nid(zone)))
+ continue;
+ show_node(zone);
+ printk("%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("%lu*%lukB ", nr[order], K(1UL) << order);
+ if (nr[order])
+ show_migration_types(types[order]);
+ }
+ printk("= %lukB\n", K(total));
+ }
+
+ hugetlb_show_meminfo();
+
+ printk("%ld total pagecache pages\n", global_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_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
+ int nr_zones)
+{
+ struct zone *zone;
+ enum zone_type zone_type = MAX_NR_ZONES;
+
+ do {
+ zone_type--;
+ zone = pgdat->node_zones + zone_type;
+ if (populated_zone(zone)) {
+ zoneref_set_zone(zone,
+ &zonelist->_zonerefs[nr_zones++]);
+ check_highest_zone(zone_type);
+ }
+ } while (zone_type);
+
+ return nr_zones;
+}
+
+
+/*
+ * zonelist_order:
+ * 0 = automatic detection of better ordering.
+ * 1 = order by ([node] distance, -zonetype)
+ * 2 = order by (-zonetype, [node] distance)
+ *
+ * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
+ * the same zonelist. So only NUMA can configure this param.
+ */
+#define ZONELIST_ORDER_DEFAULT 0
+#define ZONELIST_ORDER_NODE 1
+#define ZONELIST_ORDER_ZONE 2
+
+/* zonelist order in the kernel.
+ * set_zonelist_order() will set this to NODE or ZONE.
+ */
+static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
+static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
+
+
+#ifdef CONFIG_NUMA
+/* The value user specified ....changed by config */
+static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
+/* string for sysctl */
+#define NUMA_ZONELIST_ORDER_LEN 16
+char numa_zonelist_order[16] = "default";
+
+/*
+ * interface for configure zonelist ordering.
+ * command line option "numa_zonelist_order"
+ * = "[dD]efault - default, automatic configuration.
+ * = "[nN]ode - order by node locality, then by zone within node
+ * = "[zZ]one - order by zone, then by locality within zone
+ */
+
+static int __parse_numa_zonelist_order(char *s)
+{
+ if (*s == 'd' || *s == 'D') {
+ user_zonelist_order = ZONELIST_ORDER_DEFAULT;
+ } else if (*s == 'n' || *s == 'N') {
+ user_zonelist_order = ZONELIST_ORDER_NODE;
+ } else if (*s == 'z' || *s == 'Z') {
+ user_zonelist_order = ZONELIST_ORDER_ZONE;
+ } else {
+ printk(KERN_WARNING
+ "Ignoring invalid numa_zonelist_order value: "
+ "%s\n", s);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static __init int setup_numa_zonelist_order(char *s)
+{
+ int ret;
+
+ if (!s)
+ return 0;
+
+ ret = __parse_numa_zonelist_order(s);
+ if (ret == 0)
+ strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
+
+ return ret;
+}
+early_param("numa_zonelist_order", setup_numa_zonelist_order);
+
+/*
+ * 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 saved_string[NUMA_ZONELIST_ORDER_LEN];
+ int ret;
+ static DEFINE_MUTEX(zl_order_mutex);
+
+ mutex_lock(&zl_order_mutex);
+ if (write) {
+ if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
+ ret = -EINVAL;
+ goto out;
+ }
+ strcpy(saved_string, (char *)table->data);
+ }
+ ret = proc_dostring(table, write, buffer, length, ppos);
+ if (ret)
+ goto out;
+ if (write) {
+ int oldval = user_zonelist_order;
+
+ ret = __parse_numa_zonelist_order((char *)table->data);
+ if (ret) {
+ /*
+ * bogus value. restore saved string
+ */
+ strncpy((char *)table->data, saved_string,
+ NUMA_ZONELIST_ORDER_LEN);
+ user_zonelist_order = oldval;
+ } else if (oldval != user_zonelist_order) {
+ mutex_lock(&zonelists_mutex);
+ build_all_zonelists(NULL, NULL);
+ mutex_unlock(&zonelists_mutex);
+ }
+ }
+out:
+ mutex_unlock(&zl_order_mutex);
+ 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)
+{
+ int j;
+ struct zonelist *zonelist;
+
+ zonelist = &pgdat->node_zonelists[0];
+ for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
+ ;
+ j = build_zonelists_node(NODE_DATA(node), zonelist, j);
+ zonelist->_zonerefs[j].zone = NULL;
+ zonelist->_zonerefs[j].zone_idx = 0;
+}
+
+/*
+ * Build gfp_thisnode zonelists
+ */
+static void build_thisnode_zonelists(pg_data_t *pgdat)
+{
+ int j;
+ struct zonelist *zonelist;
+
+ zonelist = &pgdat->node_zonelists[1];
+ j = build_zonelists_node(pgdat, zonelist, 0);
+ zonelist->_zonerefs[j].zone = NULL;
+ zonelist->_zonerefs[j].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 int node_order[MAX_NUMNODES];
+
+static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
+{
+ int pos, j, node;
+ int zone_type; /* needs to be signed */
+ struct zone *z;
+ struct zonelist *zonelist;
+
+ zonelist = &pgdat->node_zonelists[0];
+ pos = 0;
+ for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
+ for (j = 0; j < nr_nodes; j++) {
+ node = node_order[j];
+ z = &NODE_DATA(node)->node_zones[zone_type];
+ if (populated_zone(z)) {
+ zoneref_set_zone(z,
+ &zonelist->_zonerefs[pos++]);
+ check_highest_zone(zone_type);
+ }
+ }
+ }
+ zonelist->_zonerefs[pos].zone = NULL;
+ zonelist->_zonerefs[pos].zone_idx = 0;
+}
+
+#if defined(CONFIG_64BIT)
+/*
+ * Devices that require DMA32/DMA are relatively rare and do not justify a
+ * penalty to every machine in case the specialised case applies. Default
+ * to Node-ordering on 64-bit NUMA machines
+ */
+static int default_zonelist_order(void)
+{
+ return ZONELIST_ORDER_NODE;
+}
+#else
+/*
+ * On 32-bit, the Normal zone needs to be preserved for allocations accessible
+ * by the kernel. If processes running on node 0 deplete the low memory zone
+ * then reclaim will occur more frequency increasing stalls and potentially
+ * be easier to OOM if a large percentage of the zone is under writeback or
+ * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
+ * Hence, default to zone ordering on 32-bit.
+ */
+static int default_zonelist_order(void)
+{
+ return ZONELIST_ORDER_ZONE;
+}
+#endif /* CONFIG_64BIT */
+
+static void set_zonelist_order(void)
+{
+ if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
+ current_zonelist_order = default_zonelist_order();
+ else
+ current_zonelist_order = user_zonelist_order;
+}
+
+static void build_zonelists(pg_data_t *pgdat)
+{
+ int j, node, load;
+ enum zone_type i;
+ nodemask_t used_mask;
+ int local_node, prev_node;
+ struct zonelist *zonelist;
+ int order = current_zonelist_order;
+
+ /* initialize zonelists */
+ for (i = 0; i < MAX_ZONELISTS; i++) {
+ zonelist = pgdat->node_zonelists + i;
+ zonelist->_zonerefs[0].zone = NULL;
+ zonelist->_zonerefs[0].zone_idx = 0;
+ }
+
+ /* 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));
+ j = 0;
+
+ 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;
+
+ prev_node = node;
+ load--;
+ if (order == ZONELIST_ORDER_NODE)
+ build_zonelists_in_node_order(pgdat, node);
+ else
+ node_order[j++] = node; /* remember order */
+ }
+
+ if (order == ZONELIST_ORDER_ZONE) {
+ /* calculate node order -- i.e., DMA last! */
+ build_zonelists_in_zone_order(pgdat, j);
+ }
+
+ build_thisnode_zonelists(pgdat);
+}
+
+/* Construct the zonelist performance cache - see further mmzone.h */
+static void build_zonelist_cache(pg_data_t *pgdat)
+{
+ struct zonelist *zonelist;
+ struct zonelist_cache *zlc;
+ struct zoneref *z;
+
+ zonelist = &pgdat->node_zonelists[0];
+ zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
+ bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
+ for (z = zonelist->_zonerefs; z->zone; z++)
+ zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
+}
+
+#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 zone *zone;
+
+ (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
+ gfp_zone(GFP_KERNEL),
+ NULL,
+ &zone);
+ return zone->node;
+}
+#endif
+
+#else /* CONFIG_NUMA */
+
+static void set_zonelist_order(void)
+{
+ current_zonelist_order = ZONELIST_ORDER_ZONE;
+}
+
+static void build_zonelists(pg_data_t *pgdat)
+{
+ int node, local_node;
+ enum zone_type j;
+ struct zonelist *zonelist;
+
+ local_node = pgdat->node_id;
+
+ zonelist = &pgdat->node_zonelists[0];
+ j = build_zonelists_node(pgdat, zonelist, 0);
+
+ /*
+ * 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;
+ j = build_zonelists_node(NODE_DATA(node), zonelist, j);
+ }
+ for (node = 0; node < local_node; node++) {
+ if (!node_online(node))
+ continue;
+ j = build_zonelists_node(NODE_DATA(node), zonelist, j);
+ }
+
+ zonelist->_zonerefs[j].zone = NULL;
+ zonelist->_zonerefs[j].zone_idx = 0;
+}
+
+/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
+static void build_zonelist_cache(pg_data_t *pgdat)
+{
+ pgdat->node_zonelists[0].zlcache_ptr = NULL;
+}
+
+#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 void setup_zone_pageset(struct zone *zone);
+
+/*
+ * Global mutex to protect against size modification of zonelists
+ * as well as to serialize pageset setup for the new populated zone.
+ */
+DEFINE_MUTEX(zonelists_mutex);
+
+/* return values int ....just for stop_machine() */
+static int __build_all_zonelists(void *data)
+{
+ int nid;
+ int cpu;
+ pg_data_t *self = data;
+
+#ifdef CONFIG_NUMA
+ memset(node_load, 0, sizeof(node_load));
+#endif
+
+ if (self && !node_online(self->node_id)) {
+ build_zonelists(self);
+ build_zonelist_cache(self);
+ }
+
+ for_each_online_node(nid) {
+ pg_data_t *pgdat = NODE_DATA(nid);
+
+ build_zonelists(pgdat);
+ build_zonelist_cache(pgdat);
+ }
+
+ /*
+ * 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);
+
+#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.
+ */
+ if (cpu_online(cpu))
+ set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
+#endif
+ }
+
+ return 0;
+}
+
+static noinline void __init
+build_all_zonelists_init(void)
+{
+ __build_all_zonelists(NULL);
+ mminit_verify_zonelist();
+ cpuset_init_current_mems_allowed();
+}
+
+/*
+ * Called with zonelists_mutex held always
+ * unless system_state == SYSTEM_BOOTING.
+ *
+ * __ref due to (1) call of __meminit annotated setup_zone_pageset
+ * [we're only called with non-NULL zone through __meminit paths] and
+ * (2) call of __init annotated helper build_all_zonelists_init
+ * [protected by SYSTEM_BOOTING].
+ */
+void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
+{
+ set_zonelist_order();
+
+ if (system_state == SYSTEM_BOOTING) {
+ build_all_zonelists_init();
+ } else {
+#ifdef CONFIG_MEMORY_HOTPLUG
+ if (zone)
+ setup_zone_pageset(zone);
+#endif
+ /* we have to stop all cpus to guarantee there is no user
+ of zonelist */
+ stop_machine(__build_all_zonelists, pgdat, NULL);
+ /* 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 in %s order, mobility grouping %s. "
+ "Total pages: %ld\n",
+ nr_online_nodes,
+ zonelist_order_name[current_zonelist_order],
+ page_group_by_mobility_disabled ? "off" : "on",
+ vm_total_pages);
+#ifdef CONFIG_NUMA
+ pr_info("Policy zone: %s\n", zone_names[policy_zone]);
+#endif
+}
+
+/*
+ * Helper functions to size the waitqueue hash table.
+ * Essentially these want to choose hash table sizes sufficiently
+ * large so that collisions trying to wait on pages are rare.
+ * But in fact, the number of active page waitqueues on typical
+ * systems is ridiculously low, less than 200. So this is even
+ * conservative, even though it seems large.
+ *
+ * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
+ * waitqueues, i.e. the size of the waitq table given the number of pages.
+ */
+#define PAGES_PER_WAITQUEUE 256
+
+#ifndef CONFIG_MEMORY_HOTPLUG
+static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
+{
+ unsigned long size = 1;
+
+ pages /= PAGES_PER_WAITQUEUE;
+
+ while (size < pages)
+ size <<= 1;
+
+ /*
+ * Once we have dozens or even hundreds of threads sleeping
+ * on IO we've got bigger problems than wait queue collision.
+ * Limit the size of the wait table to a reasonable size.
+ */
+ size = min(size, 4096UL);
+
+ return max(size, 4UL);
+}
+#else
+/*
+ * A zone's size might be changed by hot-add, so it is not possible to determine
+ * a suitable size for its wait_table. So we use the maximum size now.
+ *
+ * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
+ *
+ * i386 (preemption config) : 4096 x 16 = 64Kbyte.
+ * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
+ * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
+ *
+ * The maximum entries are prepared when a zone's memory is (512K + 256) pages
+ * or more by the traditional way. (See above). It equals:
+ *
+ * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
+ * ia64(16K page size) : = ( 8G + 4M)byte.
+ * powerpc (64K page size) : = (32G +16M)byte.
+ */
+static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
+{
+ return 4096UL;
+}
+#endif
+
+/*
+ * This is an integer logarithm so that shifts can be used later
+ * to extract the more random high bits from the multiplicative
+ * hash function before the remainder is taken.
+ */
+static inline unsigned long wait_table_bits(unsigned long size)
+{
+ return ffz(~size);
+}
+
+/*
+ * Check if a pageblock contains reserved pages
+ */
+static int pageblock_is_reserved(unsigned long start_pfn, unsigned long end_pfn)
+{
+ unsigned long pfn;
+
+ for (pfn = start_pfn; pfn < end_pfn; pfn++) {
+ if (!pfn_valid_within(pfn) || PageReserved(pfn_to_page(pfn)))
+ return 1;
+ }
+ return 0;
+}
+
+/*
+ * Mark a number of pageblocks as MIGRATE_RESERVE. The number
+ * of blocks reserved is based on min_wmark_pages(zone). The memory within
+ * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
+ * higher will lead to a bigger reserve which will get freed as contiguous
+ * blocks as reclaim kicks in
+ */
+static void setup_zone_migrate_reserve(struct zone *zone)
+{
+ unsigned long start_pfn, pfn, end_pfn, block_end_pfn;
+ struct page *page;
+ unsigned long block_migratetype;
+ int reserve;
+ int old_reserve;
+
+ /*
+ * Get the start pfn, end pfn and the number of blocks to reserve
+ * We have to be careful to be aligned to pageblock_nr_pages to
+ * make sure that we always check pfn_valid for the first page in
+ * the block.
+ */
+ start_pfn = zone->zone_start_pfn;
+ end_pfn = zone_end_pfn(zone);
+ start_pfn = roundup(start_pfn, pageblock_nr_pages);
+ reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
+ pageblock_order;
+
+ /*
+ * Reserve blocks are generally in place to help high-order atomic
+ * allocations that are short-lived. A min_free_kbytes value that
+ * would result in more than 2 reserve blocks for atomic allocations
+ * is assumed to be in place to help anti-fragmentation for the
+ * future allocation of hugepages at runtime.
+ */
+ reserve = min(2, reserve);
+ old_reserve = zone->nr_migrate_reserve_block;
+
+ /* When memory hot-add, we almost always need to do nothing */
+ if (reserve == old_reserve)
+ return;
+ zone->nr_migrate_reserve_block = reserve;
+
+ for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
+ if (!pfn_valid(pfn))
+ continue;
+ page = pfn_to_page(pfn);
+
+ /* Watch out for overlapping nodes */
+ if (page_to_nid(page) != zone_to_nid(zone))
+ continue;
+
+ block_migratetype = get_pageblock_migratetype(page);
+
+ /* Only test what is necessary when the reserves are not met */
+ if (reserve > 0) {
+ /*
+ * Blocks with reserved pages will never free, skip
+ * them.
+ */
+ block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn);
+ if (pageblock_is_reserved(pfn, block_end_pfn))
+ continue;
+
+ /* If this block is reserved, account for it */
+ if (block_migratetype == MIGRATE_RESERVE) {
+ reserve--;
+ continue;
+ }
+
+ /* Suitable for reserving if this block is movable */
+ if (block_migratetype == MIGRATE_MOVABLE) {
+ set_pageblock_migratetype(page,
+ MIGRATE_RESERVE);
+ move_freepages_block(zone, page,
+ MIGRATE_RESERVE);
+ reserve--;
+ continue;
+ }
+ } else if (!old_reserve) {
+ /*
+ * At boot time we don't need to scan the whole zone
+ * for turning off MIGRATE_RESERVE.
+ */
+ break;
+ }
+
+ /*
+ * If the reserve is met and this is a previous reserved block,
+ * take it back
+ */
+ if (block_migratetype == MIGRATE_RESERVE) {
+ set_pageblock_migratetype(page, MIGRATE_MOVABLE);
+ move_freepages_block(zone, page, MIGRATE_MOVABLE);
+ }
+ }
+}
+
+/*
+ * 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 memmap_context context)
+{
+ struct page *page;
+ unsigned long end_pfn = start_pfn + size;
+ unsigned long pfn;
+ struct zone *z;
+
+ if (highest_memmap_pfn < end_pfn - 1)
+ highest_memmap_pfn = end_pfn - 1;
+
+ z = &NODE_DATA(nid)->node_zones[zone];
+ 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 == MEMMAP_EARLY) {
+ if (!early_pfn_valid(pfn))
+ continue;
+ if (!early_pfn_in_nid(pfn, nid))
+ continue;
+ }
+ page = pfn_to_page(pfn);
+ set_page_links(page, zone, nid, pfn);
+ mminit_verify_page_links(page, zone, nid, pfn);
+ init_page_count(page);
+ page_mapcount_reset(page);
+ page_cpupid_reset_last(page);
+ 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. Later some blocks near
+ * the start are marked MIGRATE_RESERVE by
+ * setup_zone_migrate_reserve()
+ *
+ * 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.
+ */
+ if ((z->zone_start_pfn <= pfn)
+ && (pfn < zone_end_pfn(z))
+ && !(pfn & (pageblock_nr_pages - 1)))
+ set_pageblock_migratetype(page, MIGRATE_MOVABLE);
+
+ 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
+ }
+}
+
+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), MEMMAP_EARLY)
+#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. But no more than 1/2 of a meg.
+ *
+ * OK, so we don't know how big the cache is. So guess.
+ */
+ batch = zone->managed_pages / 1024;
+ if (batch * PAGE_SIZE > 512 * 1024)
+ batch = (512 * 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);
+}
+
+static 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 zone *zone;
+
+ for_each_populated_zone(zone)
+ setup_zone_pageset(zone);
+}
+
+static noinline __init_refok
+int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
+{
+ int i;
+ size_t alloc_size;
+
+ /*
+ * The per-page waitqueue mechanism uses hashed waitqueues
+ * per zone.
+ */
+ zone->wait_table_hash_nr_entries =
+ wait_table_hash_nr_entries(zone_size_pages);
+ zone->wait_table_bits =
+ wait_table_bits(zone->wait_table_hash_nr_entries);
+ alloc_size = zone->wait_table_hash_nr_entries
+ * sizeof(wait_queue_head_t);
+
+ if (!slab_is_available()) {
+ zone->wait_table = (wait_queue_head_t *)
+ memblock_virt_alloc_node_nopanic(
+ alloc_size, zone->zone_pgdat->node_id);
+ } else {
+ /*
+ * This case means that a zone whose size was 0 gets new memory
+ * via memory hot-add.
+ * But it may be the case that a new node was hot-added. In
+ * this case vmalloc() will not be able to use this new node's
+ * memory - this wait_table must be initialized to use this new
+ * node itself as well.
+ * To use this new node's memory, further consideration will be
+ * necessary.
+ */
+ zone->wait_table = vmalloc(alloc_size);
+ }
+ if (!zone->wait_table)
+ return -ENOMEM;
+
+ for (i = 0; i < zone->wait_table_hash_nr_entries; ++i)
+ init_waitqueue_head(zone->wait_table + i);
+
+ return 0;
+}
+
+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));
+}
+
+int __meminit init_currently_empty_zone(struct zone *zone,
+ unsigned long zone_start_pfn,
+ unsigned long size,
+ enum memmap_context context)
+{
+ struct pglist_data *pgdat = zone->zone_pgdat;
+ int ret;
+ ret = zone_wait_table_init(zone, size);
+ if (ret)
+ return ret;
+ pgdat->nr_zones = zone_idx(zone) + 1;
+
+ 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);
+
+ return 0;
+}
+
+#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)
+{
+ unsigned long start_pfn, end_pfn;
+ int nid;
+ /*
+ * NOTE: The following SMP-unsafe globals are only used early in boot
+ * when the kernel is running single-threaded.
+ */
+ static unsigned long __meminitdata last_start_pfn, last_end_pfn;
+ static int __meminitdata last_nid;
+
+ if (last_start_pfn <= pfn && pfn < last_end_pfn)
+ return last_nid;
+
+ nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
+ if (nid != -1) {
+ last_start_pfn = start_pfn;
+ last_end_pfn = end_pfn;
+ last_nid = nid;
+ }
+
+ return nid;
+}
+#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
+
+int __meminit early_pfn_to_nid(unsigned long pfn)
+{
+ int nid;
+
+ nid = __early_pfn_to_nid(pfn);
+ if (nid >= 0)
+ return nid;
+ /* just returns 0 */
+ return 0;
+}
+
+#ifdef CONFIG_NODES_SPAN_OTHER_NODES
+bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
+{
+ int nid;
+
+ nid = __early_pfn_to_nid(pfn);
+ if (nid >= 0 && nid != node)
+ return false;
+ return true;
+}
+#endif
+
+/**
+ * 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 (*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 *ignored)
+{
+ unsigned long zone_start_pfn, zone_end_pfn;
+
+ /* Get the start and end of the zone */
+ zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
+ zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
+ 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;
+
+ 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);
+ return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
+}
+
+#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 *zones_size)
+{
+ 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, totalpages = 0;
+ enum zone_type i;
+
+ for (i = 0; i < MAX_NR_ZONES; i++)
+ totalpages += zone_spanned_pages_in_node(pgdat->node_id, i,
+ node_start_pfn,
+ node_end_pfn,
+ zones_size);
+ pgdat->node_spanned_pages = totalpages;
+
+ realtotalpages = totalpages;
+ for (i = 0; i < MAX_NR_ZONES; i++)
+ realtotalpages -=
+ zone_absent_pages_in_node(pgdat->node_id, i,
+ node_start_pfn, node_end_pfn,
+ zholes_size);
+ 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 __init 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 __paginginit 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 __paginginit set_pageblock_order(void)
+{
+}
+
+#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
+
+static unsigned long __paginginit 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 naturally algined 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;
+}
+
+/*
+ * 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.
+ */
+static void __paginginit free_area_init_core(struct pglist_data *pgdat,
+ unsigned long node_start_pfn, unsigned long node_end_pfn,
+ unsigned long *zones_size, unsigned long *zholes_size)
+{
+ enum zone_type j;
+ int nid = pgdat->node_id;
+ unsigned long zone_start_pfn = pgdat->node_start_pfn;
+ int ret;
+
+ pgdat_resize_init(pgdat);
+#ifdef CONFIG_NUMA_BALANCING
+ spin_lock_init(&pgdat->numabalancing_migrate_lock);
+ pgdat->numabalancing_migrate_nr_pages = 0;
+ pgdat->numabalancing_migrate_next_window = jiffies;
+#endif
+ init_waitqueue_head(&pgdat->kswapd_wait);
+ init_waitqueue_head(&pgdat->pfmemalloc_wait);
+ pgdat_page_ext_init(pgdat);
+
+ for (j = 0; j < MAX_NR_ZONES; j++) {
+ struct zone *zone = pgdat->node_zones + j;
+ unsigned long size, realsize, freesize, memmap_pages;
+
+ size = zone_spanned_pages_in_node(nid, j, node_start_pfn,
+ node_end_pfn, zones_size);
+ realsize = freesize = size - zone_absent_pages_in_node(nid, j,
+ node_start_pfn,
+ node_end_pfn,
+ zholes_size);
+
+ /*
+ * 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, realsize);
+ 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
+ printk(KERN_WARNING
+ " %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;
+
+ zone->spanned_pages = size;
+ zone->present_pages = realsize;
+ /*
+ * 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->managed_pages = is_highmem_idx(j) ? realsize : freesize;
+#ifdef CONFIG_NUMA
+ zone->node = nid;
+ zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio)
+ / 100;
+ zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100;
+#endif
+ zone->name = zone_names[j];
+ spin_lock_init(&zone->lock);
+ spin_lock_init(&zone->lru_lock);
+ zone_seqlock_init(zone);
+ zone->zone_pgdat = pgdat;
+ zone_pcp_init(zone);
+
+ /* For bootup, initialized properly in watermark setup */
+ mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages);
+
+ lruvec_init(&zone->lruvec);
+ if (!size)
+ continue;
+
+ set_pageblock_order();
+ setup_usemap(pgdat, zone, zone_start_pfn, size);
+ ret = init_currently_empty_zone(zone, zone_start_pfn,
+ size, MEMMAP_EARLY);
+ BUG_ON(ret);
+ memmap_init(size, nid, j, zone_start_pfn);
+ zone_start_pfn += size;
+ }
+}
+
+static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
+{
+ /* Skip empty nodes */
+ if (!pgdat->node_spanned_pages)
+ return;
+
+#ifdef CONFIG_FLAT_NODE_MEM_MAP
+ /* ia64 gets its own node_mem_map, before this, without bootmem */
+ if (!pgdat->node_mem_map) {
+ unsigned long size, start, 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.
+ */
+ start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
+ end = pgdat_end_pfn(pgdat);
+ end = ALIGN(end, MAX_ORDER_NR_PAGES);
+ size = (end - start) * sizeof(struct page);
+ map = alloc_remap(pgdat->node_id, size);
+ if (!map)
+ map = memblock_virt_alloc_node_nopanic(size,
+ pgdat->node_id);
+ pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
+ }
+#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;
+#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
+ if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
+ mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
+#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
+ }
+#endif
+#endif /* CONFIG_FLAT_NODE_MEM_MAP */
+}
+
+void __paginginit 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->classzone_idx);
+
+ pgdat->node_id = nid;
+ pgdat->node_start_pfn = node_start_pfn;
+#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, ((u64)end_pfn << PAGE_SHIFT) - 1);
+#endif
+ calculate_node_totalpages(pgdat, start_pfn, end_pfn,
+ zones_size, zholes_size);
+
+ alloc_node_mem_map(pgdat);
+#ifdef CONFIG_FLAT_NODE_MEM_MAP
+ printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
+ nid, (unsigned long)pgdat,
+ (unsigned long)pgdat->node_mem_map);
+#endif
+
+ free_area_init_core(pgdat, start_pfn, end_pfn,
+ zones_size, zholes_size);
+}
+
+#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 node;
+ unsigned int highest = 0;
+
+ for_each_node_mask(node, node_possible_map)
+ highest = node;
+ 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) {
+ printk(KERN_WARNING
+ "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 movablecore=nn[KMG] 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);
+ corepages = totalpages - required_movablecore;
+
+ required_kernelcore = max(required_kernelcore, corepages);
+ }
+
+ /* If kernelcore was not specified, there is no ZONE_MOVABLE */
+ if (!required_kernelcore)
+ 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++)
+ zone_movable_pfn[nid] =
+ roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
+
+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));
+ arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
+ arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
+ for (i = 1; i < MAX_NR_ZONES; i++) {
+ if (i == ZONE_MOVABLE)
+ continue;
+ arch_zone_lowest_possible_pfn[i] =
+ arch_zone_highest_possible_pfn[i-1];
+ arch_zone_highest_possible_pfn[i] =
+ max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
+ }
+ arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
+ arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
+
+ /* 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();
+ 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 long coremem;
+ if (!p)
+ return -EINVAL;
+
+ coremem = memparse(p, &p);
+ *core = coremem >> PAGE_SHIFT;
+
+ /* Paranoid check that UL is enough for the coremem value */
+ WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
+
+ 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)
+{
+ return cmdline_parse_core(p, &required_kernelcore);
+}
+
+/*
+ * 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);
+}
+
+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++) {
+ if ((unsigned int)poison <= 0xFF)
+ memset(pos, poison, PAGE_SIZE);
+ free_reserved_page(virt_to_page(pos));
+ }
+
+ if (pages && s)
+ pr_info("Freeing %s memory: %ldK (%p - %p)\n",
+ s, pages << (PAGE_SHIFT - 10), start, end);
+
+ 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 <= pos && pos < end && 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 present_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)
+{
+ free_area_init_node(0, zones_size,
+ __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
+}
+
+static int page_alloc_cpu_notify(struct notifier_block *self,
+ unsigned long action, void *hcpu)
+{
+ int cpu = (unsigned long)hcpu;
+
+ if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
+ 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 NOTIFY_OK;
+}
+
+void __init page_alloc_init(void)
+{
+ hotcpu_notifier(page_alloc_cpu_notify, 0);
+ local_irq_lock_init(pa_lock);
+}
+
+/*
+ * calculate_totalreserve_pages - called when sysctl_lower_zone_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) {
+ 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;
+ reserve_pages += max;
+ /*
+ * Lowmem reserves are not available to
+ * GFP_HIGHUSER page cache allocations and
+ * kswapd tries to balance zones to their high
+ * watermark. As a result, neither should be
+ * regarded as dirtyable memory, to prevent a
+ * situation where reclaim has to clean pages
+ * in order to balance the zones.
+ */
+ zone->dirty_balance_reserve = max;
+ }
+ }
+ dirty_balance_reserve = reserve_pages;
+ totalreserve_pages = reserve_pages;
+}
+
+/*
+ * setup_per_zone_lowmem_reserve - called whenever
+ * sysctl_lower_zone_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--;
+
+ if (sysctl_lowmem_reserve_ratio[idx] < 1)
+ sysctl_lowmem_reserve_ratio[idx] = 1;
+
+ lower_zone = pgdat->node_zones + idx;
+ 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;
+ }
+
+ zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2);
+ zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
+
+ __mod_zone_page_state(zone, NR_ALLOC_BATCH,
+ high_wmark_pages(zone) - low_wmark_pages(zone) -
+ atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
+
+ setup_zone_migrate_reserve(zone);
+ 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)
+{
+ mutex_lock(&zonelists_mutex);
+ __setup_per_zone_wmarks();
+ mutex_unlock(&zonelists_mutex);
+}
+
+/*
+ * The inactive anon list should be small enough that the VM never has to
+ * do too much work, but large enough that each inactive page has a chance
+ * to be referenced again before it is swapped out.
+ *
+ * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
+ * INACTIVE_ANON pages on this zone's LRU, maintained by the
+ * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
+ * the anonymous pages are kept on the inactive list.
+ *
+ * total target max
+ * memory ratio inactive anon
+ * -------------------------------------
+ * 10MB 1 5MB
+ * 100MB 1 50MB
+ * 1GB 3 250MB
+ * 10GB 10 0.9GB
+ * 100GB 31 3GB
+ * 1TB 101 10GB
+ * 10TB 320 32GB
+ */
+static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
+{
+ unsigned int gb, ratio;
+
+ /* Zone size in gigabytes */
+ gb = zone->managed_pages >> (30 - PAGE_SHIFT);
+ if (gb)
+ ratio = int_sqrt(10 * gb);
+ else
+ ratio = 1;
+
+ zone->inactive_ratio = ratio;
+}
+
+static void __meminit setup_per_zone_inactive_ratio(void)
+{
+ struct zone *zone;
+
+ for_each_zone(zone)
+ calculate_zone_inactive_ratio(zone);
+}
+
+/*
+ * 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();
+ setup_per_zone_inactive_ratio();
+ return 0;
+}
+module_init(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;
+}
+
+#ifdef CONFIG_NUMA
+int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
+ void __user *buffer, size_t *length, loff_t *ppos)
+{
+ struct zone *zone;
+ int rc;
+
+ rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
+ if (rc)
+ return rc;
+
+ for_each_zone(zone)
+ zone->min_unmapped_pages = (zone->managed_pages *
+ sysctl_min_unmapped_ratio) / 100;
+ return 0;
+}
+
+int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
+ void __user *buffer, size_t *length, loff_t *ppos)
+{
+ struct zone *zone;
+ int rc;
+
+ rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
+ if (rc)
+ return rc;
+
+ for_each_zone(zone)
+ zone->min_slab_pages = (zone->managed_pages *
+ sysctl_min_slab_ratio) / 100;
+ 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;
+}
+
+int hashdist = HASHDIST_DEFAULT;
+
+#ifdef CONFIG_NUMA
+static int __init set_hashdist(char *str)
+{
+ if (!str)
+ return 0;
+ hashdist = simple_strtoul(str, &str, 0);
+ return 1;
+}
+__setup("hashdist=", set_hashdist);
+#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;
+
+ /* allow the kernel cmdline to have a say */
+ if (!numentries) {
+ /* round applicable memory size up to nearest megabyte */
+ numentries = nr_kernel_pages;
+
+ /* It isn't necessary when PAGE_SIZE >= 1MB */
+ if (PAGE_SHIFT < 20)
+ numentries = round_up(numentries, (1<<20)/PAGE_SIZE);
+
+ /* 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);
+
+ do {
+ size = bucketsize << log2qty;
+ if (flags & HASH_EARLY)
+ table = memblock_virt_alloc_nopanic(size, 0);
+ else if (hashdist)
+ table = __vmalloc(size, GFP_ATOMIC, 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_ATOMIC);
+ kmemleak_alloc(table, size, 1, GFP_ATOMIC);
+ }
+ }
+ } while (!table && size > PAGE_SIZE && --log2qty);
+
+ if (!table)
+ panic("Failed to allocate %s hash table\n", tablename);
+
+ printk(KERN_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;
+}
+
+/* Return a pointer to the bitmap storing bits affecting a block of pages */
+static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
+ unsigned long pfn)
+{
+#ifdef CONFIG_SPARSEMEM
+ return __pfn_to_section(pfn)->pageblock_flags;
+#else
+ return zone->pageblock_flags;
+#endif /* CONFIG_SPARSEMEM */
+}
+
+static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
+{
+#ifdef CONFIG_SPARSEMEM
+ pfn &= (PAGES_PER_SECTION-1);
+ return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
+#else
+ pfn = pfn - round_down(zone->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
+ */
+unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
+ unsigned long end_bitidx,
+ unsigned long mask)
+{
+ struct zone *zone;
+ unsigned long *bitmap;
+ unsigned long bitidx, word_bitidx;
+ unsigned long word;
+
+ zone = page_zone(page);
+ bitmap = get_pageblock_bitmap(zone, pfn);
+ bitidx = pfn_to_bitidx(zone, 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;
+}
+
+/**
+ * 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)
+{
+ struct zone *zone;
+ unsigned long *bitmap;
+ unsigned long bitidx, word_bitidx;
+ unsigned long old_word, word;
+
+ BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
+
+ zone = page_zone(page);
+ bitmap = get_pageblock_bitmap(zone, pfn);
+ bitidx = pfn_to_bitidx(zone, pfn);
+ word_bitidx = bitidx / BITS_PER_LONG;
+ bitidx &= (BITS_PER_LONG-1);
+
+ VM_BUG_ON_PAGE(!zone_spans_pfn(zone, 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;
+ }
+}
+
+/*
+ * 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. It means you can't
+ * expect this function should be exact.
+ */
+bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
+ bool skip_hwpoisoned_pages)
+{
+ unsigned long pfn, iter, found;
+ int mt;
+
+ /*
+ * For avoiding noise data, lru_add_drain_all() should be called
+ * If ZONE_MOVABLE, the zone never contains unmovable pages
+ */
+ if (zone_idx(zone) == ZONE_MOVABLE)
+ return false;
+ mt = get_pageblock_migratetype(page);
+ if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
+ 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);
+
+ /*
+ * 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)) {
+ iter = round_up(iter + 1, 1<<compound_order(page)) - 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->_count is zero at all time.
+ */
+ if (!atomic_read(&page->_count)) {
+ 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 (!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)
+ return true;
+ }
+ return false;
+}
+
+bool is_pageblock_removable_nolock(struct page *page)
+{
+ struct zone *zone;
+ unsigned long pfn;
+
+ /*
+ * We have to be careful here because we are iterating over memory
+ * sections which are not zone aware so we might end up outside of
+ * the zone but still within the section.
+ * We have to take care about the node as well. If the node is offline
+ * its NODE_DATA will be NULL - see page_zone.
+ */
+ if (!node_online(page_to_nid(page)))
+ return false;
+
+ zone = page_zone(page);
+ pfn = page_to_pfn(page);
+ if (!zone_spans_pfn(zone, pfn))
+ return false;
+
+ return !has_unmovable_pages(zone, page, 0, true);
+}
+
+#ifdef 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_CMA);
+ }
+ 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.
+ *
+ * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
+ * aligned, however it's the caller's responsibility to guarantee that
+ * we are the only thread that changes migrate type of pageblocks the
+ * pages fall in.
+ *
+ * The PFN range must belong to a single zone.
+ *
+ * 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)
+{
+ unsigned long outer_start, outer_end;
+ int ret = 0, order;
+
+ struct compact_control cc = {
+ .nr_migratepages = 0,
+ .order = -1,
+ .zone = page_zone(pfn_to_page(start)),
+ .mode = MIGRATE_SYNC,
+ .ignore_skip_hint = true,
+ };
+ 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;
+
+ ret = __alloc_contig_migrate_range(&cc, start, end);
+ if (ret)
+ goto done;
+
+ /*
+ * 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) {
+ ret = -EBUSY;
+ goto done;
+ }
+ outer_start &= ~0UL << order;
+ }
+
+ /* Make sure the range is really isolated. */
+ if (test_pages_isolated(outer_start, end, false)) {
+ pr_info("%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
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+/*
+ * 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);
+}
+#endif
+
+void zone_pcp_reset(struct zone *zone)
+{
+ unsigned long flags;
+ int cpu;
+ struct per_cpu_pageset *pset;
+
+ /* avoid races with drain_pages() */
+ local_lock_irqsave(pa_lock, 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_unlock_irqrestore(pa_lock, flags);
+}
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+/*
+ * All pages in the range must be 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;
+ 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
+ printk(KERN_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
+
+#ifdef CONFIG_MEMORY_FAILURE
+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;
+}
+#endif
Code Review / kvmfornfv.git / blobdiff