| /* |
| * 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/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_cgroup.h> |
| #include <linux/debugobjects.h> |
| #include <linux/kmemleak.h> |
| #include <linux/memory.h> |
| #include <linux/compaction.h> |
| #include <trace/events/kmem.h> |
| #include <linux/ftrace_event.h> |
| #include <linux/memcontrol.h> |
| #include <linux/prefetch.h> |
| #include <linux/page-debug-flags.h> |
| |
| #include <asm/tlbflush.h> |
| #include <asm/div64.h> |
| #include "internal.h" |
| |
| #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_); |
| #endif |
| |
| /* |
| * Array of node states. |
| */ |
| nodemask_t node_states[NR_NODE_STATES] __read_mostly = { |
| [N_POSSIBLE] = NODE_MASK_ALL, |
| [N_ONLINE] = { { [0] = 1UL } }, |
| #ifndef CONFIG_NUMA |
| [N_NORMAL_MEMORY] = { { [0] = 1UL } }, |
| #ifdef CONFIG_HIGHMEM |
| [N_HIGH_MEMORY] = { { [0] = 1UL } }, |
| #endif |
| [N_CPU] = { { [0] = 1UL } }, |
| #endif /* NUMA */ |
| }; |
| EXPORT_SYMBOL(node_states); |
| |
| unsigned long totalram_pages __read_mostly; |
| unsigned long totalreserve_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 (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; |
| |
| 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 |
| |
| int page_group_by_mobility_disabled __read_mostly; |
| |
| static void set_pageblock_migratetype(struct page *page, int migratetype) |
| { |
| |
| if (unlikely(page_group_by_mobility_disabled)) |
| migratetype = MIGRATE_UNMOVABLE; |
| |
| set_pageblock_flags_group(page, (unsigned long)migratetype, |
| PB_migrate, PB_migrate_end); |
| } |
| |
| bool oom_killer_disabled __read_mostly; |
| |
| #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); |
| |
| do { |
| seq = zone_span_seqbegin(zone); |
| if (pfn >= zone->zone_start_pfn + zone->spanned_pages) |
| ret = 1; |
| else if (pfn < zone->zone_start_pfn) |
| ret = 1; |
| } while (zone_span_seqretry(zone, seq)); |
| |
| 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) |
| { |
| static unsigned long resume; |
| static unsigned long nr_shown; |
| static unsigned long nr_unshown; |
| |
| /* Don't complain about poisoned pages */ |
| if (PageHWPoison(page)) { |
| reset_page_mapcount(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(page); |
| |
| print_modules(); |
| dump_stack(); |
| out: |
| /* Leave bad fields for debug, except PageBuddy could make trouble */ |
| reset_page_mapcount(page); /* remove PageBuddy */ |
| add_taint(TAINT_BAD_PAGE); |
| } |
| |
| /* |
| * 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; |
| __SetPageTail(p); |
| set_page_count(p, 0); |
| p->first_page = page; |
| } |
| } |
| |
| /* update __split_huge_page_refcount if you change this function */ |
| static int destroy_compound_page(struct page *page, unsigned long order) |
| { |
| int i; |
| int nr_pages = 1 << order; |
| int bad = 0; |
| |
| if (unlikely(compound_order(page) != order) || |
| unlikely(!PageHead(page))) { |
| bad_page(page); |
| bad++; |
| } |
| |
| __ClearPageHead(page); |
| |
| for (i = 1; i < nr_pages; i++) { |
| struct page *p = page + i; |
| |
| if (unlikely(!PageTail(p) || (p->first_page != page))) { |
| bad_page(page); |
| bad++; |
| } |
| __ClearPageTail(p); |
| } |
| |
| return bad; |
| } |
| |
| static inline void prep_zero_page(struct page *page, 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; |
| |
| 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_flag(struct page *page) |
| { |
| __set_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags); |
| } |
| |
| static inline void clear_page_guard_flag(struct page *page) |
| { |
| __clear_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags); |
| } |
| #else |
| static inline void set_page_guard_flag(struct page *page) { } |
| static inline void clear_page_guard_flag(struct page *page) { } |
| #endif |
| |
| static inline void set_page_order(struct page *page, 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); |
| } |
| |
| /* |
| * Locate the struct page for both the matching buddy in our |
| * pair (buddy1) and the combined O(n+1) page they form (page). |
| * |
| * 1) Any buddy B1 will have an order O twin B2 which satisfies |
| * the following equation: |
| * B2 = B1 ^ (1 << O) |
| * For example, if the starting buddy (buddy2) is #8 its order |
| * 1 buddy is #10: |
| * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 |
| * |
| * 2) Any buddy B will have an order O+1 parent P which |
| * satisfies the following equation: |
| * P = B & ~(1 << O) |
| * |
| * Assumption: *_mem_map is contiguous at least up to MAX_ORDER |
| */ |
| static inline unsigned long |
| __find_buddy_index(unsigned long page_idx, unsigned int order) |
| { |
| return page_idx ^ (1 << order); |
| } |
| |
| /* |
| * 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 -2. |
| * Setting, clearing, and testing _mapcount -2 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, |
| int order) |
| { |
| if (!pfn_valid_within(page_to_pfn(buddy))) |
| return 0; |
| |
| if (page_zone_id(page) != page_zone_id(buddy)) |
| return 0; |
| |
| if (page_is_guard(buddy) && page_order(buddy) == order) { |
| VM_BUG_ON(page_count(buddy) != 0); |
| return 1; |
| } |
| |
| if (PageBuddy(buddy) && page_order(buddy) == order) { |
| VM_BUG_ON(page_count(buddy) != 0); |
| 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 -2. 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. |
| * |
| * -- wli |
| */ |
| |
| static inline void __free_one_page(struct page *page, |
| 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; |
| |
| if (unlikely(PageCompound(page))) |
| if (unlikely(destroy_compound_page(page, order))) |
| return; |
| |
| VM_BUG_ON(migratetype == -1); |
| |
| page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1); |
| |
| VM_BUG_ON(page_idx & ((1 << order) - 1)); |
| VM_BUG_ON(bad_range(zone, 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_flag(buddy); |
| set_page_private(page, 0); |
| __mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order); |
| } 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 = 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++; |
| } |
| |
| /* |
| * free_page_mlock() -- clean up attempts to free and mlocked() page. |
| * Page should not be on lru, so no need to fix that up. |
| * free_pages_check() will verify... |
| */ |
| static inline void free_page_mlock(struct page *page) |
| { |
| __dec_zone_page_state(page, NR_MLOCK); |
| __count_vm_event(UNEVICTABLE_MLOCKFREED); |
| } |
| |
| static inline int free_pages_check(struct page *page) |
| { |
| if (unlikely(page_mapcount(page) | |
| (page->mapping != NULL) | |
| (atomic_read(&page->_count) != 0) | |
| (page->flags & PAGE_FLAGS_CHECK_AT_FREE) | |
| (mem_cgroup_bad_page_check(page)))) { |
| bad_page(page); |
| return 1; |
| } |
| if (page->flags & PAGE_FLAGS_CHECK_AT_PREP) |
| page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; |
| return 0; |
| } |
| |
| /* |
| * Frees a number of pages from the PCP lists |
| * Assumes all pages on list are in same zone, and of same order. |
| * count is the number of pages to free. |
| * |
| * If the zone was previously in an "all pages pinned" state then look to |
| * see if this freeing clears that state. |
| * |
| * And clear the zone's pages_scanned counter, to hold off the "all pages are |
| * pinned" detection logic. |
| */ |
| static void free_pcppages_bulk(struct zone *zone, int count, |
| struct per_cpu_pages *pcp) |
| { |
| int migratetype = 0; |
| int batch_free = 0; |
| int to_free = count; |
| |
| spin_lock(&zone->lock); |
| zone->all_unreclaimable = 0; |
| zone->pages_scanned = 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 = &pcp->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_entry(list->prev, struct page, lru); |
| /* must delete as __free_one_page list manipulates */ |
| list_del(&page->lru); |
| /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */ |
| __free_one_page(page, zone, 0, page_private(page)); |
| trace_mm_page_pcpu_drain(page, 0, page_private(page)); |
| } while (--to_free && --batch_free && !list_empty(list)); |
| } |
| __mod_zone_page_state(zone, NR_FREE_PAGES, count); |
| spin_unlock(&zone->lock); |
| } |
| |
| static void free_one_page(struct zone *zone, struct page *page, int order, |
| int migratetype) |
| { |
| spin_lock(&zone->lock); |
| zone->all_unreclaimable = 0; |
| zone->pages_scanned = 0; |
| |
| __free_one_page(page, zone, order, migratetype); |
| __mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order); |
| spin_unlock(&zone->lock); |
| } |
| |
| static bool free_pages_prepare(struct page *page, unsigned int order) |
| { |
| int i; |
| int bad = 0; |
| |
| trace_mm_page_free(page, order); |
| kmemcheck_free_shadow(page, order); |
| |
| if (PageAnon(page)) |
| page->mapping = NULL; |
| for (i = 0; i < (1 << order); i++) |
| bad += free_pages_check(page + i); |
| if (bad) |
| return false; |
| |
| 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 wasMlocked = __TestClearPageMlocked(page); |
| |
| if (!free_pages_prepare(page, order)) |
| return; |
| |
| local_irq_save(flags); |
| if (unlikely(wasMlocked)) |
| free_page_mlock(page); |
| __count_vm_events(PGFREE, 1 << order); |
| free_one_page(page_zone(page), page, order, |
| get_pageblock_migratetype(page)); |
| local_irq_restore(flags); |
| } |
| |
| void __meminit __free_pages_bootmem(struct page *page, unsigned int order) |
| { |
| unsigned int nr_pages = 1 << order; |
| unsigned int loop; |
| |
| prefetchw(page); |
| for (loop = 0; loop < nr_pages; loop++) { |
| struct page *p = &page[loop]; |
| |
| if (loop + 1 < nr_pages) |
| prefetchw(p + 1); |
| __ClearPageReserved(p); |
| set_page_count(p, 0); |
| } |
| |
| set_page_refcounted(page); |
| __free_pages(page, order); |
| } |
| |
| |
| /* |
| * 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. |
| * |
| * -- wli |
| */ |
| 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(bad_range(zone, &page[size])); |
| |
| #ifdef CONFIG_DEBUG_PAGEALLOC |
| if (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 |
| */ |
| INIT_LIST_HEAD(&page[size].lru); |
| set_page_guard_flag(&page[size]); |
| set_page_private(&page[size], high); |
| /* Guard pages are not available for any usage */ |
| __mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << high)); |
| continue; |
| } |
| #endif |
| 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) |
| { |
| if (unlikely(page_mapcount(page) | |
| (page->mapping != NULL) | |
| (atomic_read(&page->_count) != 0) | |
| (page->flags & PAGE_FLAGS_CHECK_AT_PREP) | |
| (mem_cgroup_bad_page_check(page)))) { |
| bad_page(page); |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int prep_new_page(struct page *page, int order, gfp_t gfp_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); |
| |
| if (gfp_flags & __GFP_ZERO) |
| prep_zero_page(page, order, gfp_flags); |
| |
| if (order && (gfp_flags & __GFP_COMP)) |
| prep_compound_page(page, order); |
| |
| 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); |
| 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][MIGRATE_TYPES-1] = { |
| [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, |
| [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, |
| [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE }, |
| [MIGRATE_RESERVE] = { MIGRATE_RESERVE, MIGRATE_RESERVE, MIGRATE_RESERVE }, /* Never used */ |
| }; |
| |
| /* |
| * Move the free pages in a range to the free lists of the requested type. |
| * Note that start_page and end_pages are not aligned on a pageblock |
| * boundary. If alignment is required, use move_freepages_block() |
| */ |
| static int move_freepages(struct zone *zone, |
| struct page *start_page, struct page *end_page, |
| int migratetype) |
| { |
| 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 |
| */ |
| 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_to_nid(page) != zone_to_nid(zone)); |
| |
| 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]); |
| page += 1 << order; |
| pages_moved += 1 << order; |
| } |
| |
| return pages_moved; |
| } |
| |
| static 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 (start_pfn < zone->zone_start_pfn) |
| start_page = page; |
| if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages) |
| 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; |
| } |
| } |
| |
| /* Remove an element from the buddy allocator from the fallback list */ |
| static inline struct page * |
| __rmqueue_fallback(struct zone *zone, int order, int start_migratetype) |
| { |
| struct free_area * area; |
| int current_order; |
| struct page *page; |
| int migratetype, i; |
| |
| /* Find the largest possible block of pages in the other list */ |
| for (current_order = MAX_ORDER-1; current_order >= order; |
| --current_order) { |
| for (i = 0; i < MIGRATE_TYPES - 1; i++) { |
| migratetype = fallbacks[start_migratetype][i]; |
| |
| /* MIGRATE_RESERVE handled later if necessary */ |
| if (migratetype == MIGRATE_RESERVE) |
| continue; |
| |
| 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); |
| area->nr_free--; |
| |
| /* |
| * If breaking a large block of pages, move all free |
| * pages to the preferred allocation list. If falling |
| * back for a reclaimable kernel allocation, be more |
| * aggressive about taking ownership of free pages |
| */ |
| if (unlikely(current_order >= (pageblock_order >> 1)) || |
| start_migratetype == MIGRATE_RECLAIMABLE || |
| page_group_by_mobility_disabled) { |
| unsigned long pages; |
| pages = move_freepages_block(zone, page, |
| start_migratetype); |
| |
| /* 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_migratetype); |
| |
| migratetype = start_migratetype; |
| } |
| |
| /* Remove the page from the freelists */ |
| list_del(&page->lru); |
| rmv_page_order(page); |
| |
| /* Take ownership for orders >= pageblock_order */ |
| if (current_order >= pageblock_order) |
| change_pageblock_range(page, current_order, |
| start_migratetype); |
| |
| expand(zone, page, order, current_order, area, migratetype); |
| |
| trace_mm_page_alloc_extfrag(page, order, current_order, |
| start_migratetype, migratetype); |
| |
| 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) { |
| 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, int 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 == 0)) |
| list_add(&page->lru, list); |
| else |
| list_add_tail(&page->lru, list); |
| set_page_private(page, migratetype); |
| list = &page->lru; |
| } |
| __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; |
| int to_drain; |
| |
| local_irq_save(flags); |
| if (pcp->count >= pcp->batch) |
| to_drain = pcp->batch; |
| else |
| to_drain = pcp->count; |
| free_pcppages_bulk(zone, to_drain, pcp); |
| pcp->count -= to_drain; |
| local_irq_restore(flags); |
| } |
| #endif |
| |
| /* |
| * Drain pages of 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) |
| { |
| unsigned long flags; |
| struct zone *zone; |
| |
| for_each_populated_zone(zone) { |
| struct per_cpu_pageset *pset; |
| struct per_cpu_pages *pcp; |
| |
| local_irq_save(flags); |
| pset = per_cpu_ptr(zone->pageset, cpu); |
| |
| pcp = &pset->pcp; |
| if (pcp->count) { |
| free_pcppages_bulk(zone, pcp->count, pcp); |
| pcp->count = 0; |
| } |
| local_irq_restore(flags); |
| } |
| } |
| |
| /* |
| * Spill all of this CPU's per-cpu pages back into the buddy allocator. |
| */ |
| void drain_local_pages(void *arg) |
| { |
| drain_pages(smp_processor_id()); |
| } |
| |
| /* |
| * Spill all the per-cpu pages from all CPUs back into the buddy allocator |
| */ |
| void drain_all_pages(void) |
| { |
| on_each_cpu(drain_local_pages, NULL, 1); |
| } |
| |
| #ifdef CONFIG_HIBERNATION |
| |
| void mark_free_pages(struct zone *zone) |
| { |
| unsigned long pfn, max_zone_pfn; |
| unsigned long flags; |
| int order, t; |
| struct list_head *curr; |
| |
| if (!zone->spanned_pages) |
| return; |
| |
| spin_lock_irqsave(&zone->lock, flags); |
| |
| max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; |
| 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 == 1 ? free a cold page : free a hot page |
| */ |
| void free_hot_cold_page(struct page *page, int cold) |
| { |
| struct zone *zone = page_zone(page); |
| struct per_cpu_pages *pcp; |
| unsigned long flags; |
| int migratetype; |
| int wasMlocked = __TestClearPageMlocked(page); |
| |
| if (!free_pages_prepare(page, 0)) |
| return; |
| |
| migratetype = get_pageblock_migratetype(page); |
| set_page_private(page, migratetype); |
| local_irq_save(flags); |
| if (unlikely(wasMlocked)) |
| free_page_mlock(page); |
| __count_vm_event(PGFREE); |
| |
| /* |
| * We only track unmovable, reclaimable and movable on pcp lists. |
| * Free ISOLATE pages back to the allocator because they are being |
| * offlined but treat 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(migratetype == MIGRATE_ISOLATE)) { |
| free_one_page(zone, page, 0, migratetype); |
| goto out; |
| } |
| migratetype = MIGRATE_MOVABLE; |
| } |
| |
| pcp = &this_cpu_ptr(zone->pageset)->pcp; |
| if (cold) |
| list_add_tail(&page->lru, &pcp->lists[migratetype]); |
| else |
| list_add(&page->lru, &pcp->lists[migratetype]); |
| pcp->count++; |
| if (pcp->count >= pcp->high) { |
| free_pcppages_bulk(zone, pcp->batch, pcp); |
| pcp->count -= pcp->batch; |
| } |
| |
| out: |
| local_irq_restore(flags); |
| } |
| |
| /* |
| * Free a list of 0-order pages |
| */ |
| void free_hot_cold_page_list(struct list_head *list, int 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(PageCompound(page)); |
| VM_BUG_ON(!page_count(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 |
| |
| for (i = 1; i < (1 << order); i++) |
| set_page_refcounted(page + i); |
| } |
| |
| /* |
| * 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; |
| unsigned long watermark; |
| struct zone *zone; |
| |
| BUG_ON(!PageBuddy(page)); |
| |
| zone = page_zone(page); |
| order = page_order(page); |
| |
| /* 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; |
| |
| /* Remove page from free list */ |
| list_del(&page->lru); |
| zone->free_area[order].nr_free--; |
| rmv_page_order(page); |
| __mod_zone_page_state(zone, NR_FREE_PAGES, -(1UL << order)); |
| |
| /* Split into individual pages */ |
| set_page_refcounted(page); |
| split_page(page, order); |
| |
| if (order >= pageblock_order - 1) { |
| struct page *endpage = page + (1 << order) - 1; |
| for (; page < endpage; page += pageblock_nr_pages) |
| set_pageblock_migratetype(page, MIGRATE_MOVABLE); |
| } |
| |
| return 1 << order; |
| } |
| |
| /* |
| * Really, prep_compound_page() should be called from __rmqueue_bulk(). But |
| * we cheat by calling it from here, in the order > 0 path. Saves a branch |
| * or two. |
| */ |
| static inline |
| struct page *buffered_rmqueue(struct zone *preferred_zone, |
| struct zone *zone, int order, gfp_t gfp_flags, |
| int migratetype) |
| { |
| unsigned long flags; |
| struct page *page; |
| int cold = !!(gfp_flags & __GFP_COLD); |
| |
| again: |
| if (likely(order == 0)) { |
| struct per_cpu_pages *pcp; |
| struct list_head *list; |
| |
| local_irq_save(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); |
| } |
| spin_lock_irqsave(&zone->lock, flags); |
| page = __rmqueue(zone, order, migratetype); |
| spin_unlock(&zone->lock); |
| if (!page) |
| goto failed; |
| __mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order)); |
| } |
| |
| __count_zone_vm_events(PGALLOC, zone, 1 << order); |
| zone_statistics(preferred_zone, zone, gfp_flags); |
| local_irq_restore(flags); |
| |
| VM_BUG_ON(bad_range(zone, page)); |
| if (prep_new_page(page, order, gfp_flags)) |
| goto again; |
| return page; |
| |
| failed: |
| local_irq_restore(flags); |
| return NULL; |
| } |
| |
| /* The ALLOC_WMARK bits are used as an index to zone->watermark */ |
| #define ALLOC_WMARK_MIN WMARK_MIN |
| #define ALLOC_WMARK_LOW WMARK_LOW |
| #define ALLOC_WMARK_HIGH WMARK_HIGH |
| #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */ |
| |
| /* Mask to get the watermark bits */ |
| #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1) |
| |
| #define ALLOC_HARDER 0x10 /* try to alloc harder */ |
| #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ |
| #define ALLOC_CPUSET 0x40 /* check for correct cpuset */ |
| |
| #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 int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) |
| { |
| if (order < fail_page_alloc.min_order) |
| return 0; |
| if (gfp_mask & __GFP_NOFAIL) |
| return 0; |
| if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM)) |
| return 0; |
| if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT)) |
| return 0; |
| |
| 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 int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) |
| { |
| return 0; |
| } |
| |
| #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, int order, unsigned long mark, |
| int classzone_idx, int alloc_flags, long free_pages) |
| { |
| /* free_pages my go negative - that's OK */ |
| long min = mark; |
| int o; |
| |
| free_pages -= (1 << order) - 1; |
| if (alloc_flags & ALLOC_HIGH) |
| min -= min / 2; |
| if (alloc_flags & ALLOC_HARDER) |
| min -= min / 4; |
| |
| if (free_pages <= 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, 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, 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 in zonelist, then |
| * returns a pointer to the allowed node mask (either the current |
| * tasks mems_allowed, or node_states[N_HIGH_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_HIGH_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); |
| } |
| |
| #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) |
| { |
| } |
| #endif /* CONFIG_NUMA */ |
| |
| /* |
| * get_page_from_freelist goes through the zonelist trying to allocate |
| * a page. |
| */ |
| static struct page * |
| get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order, |
| struct zonelist *zonelist, int high_zoneidx, int alloc_flags, |
| struct zone *preferred_zone, int migratetype) |
| { |
| struct zoneref *z; |
| struct page *page = NULL; |
| int classzone_idx; |
| 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 */ |
| |
| classzone_idx = zone_idx(preferred_zone); |
| zonelist_scan: |
| /* |
| * Scan zonelist, looking for a zone with enough free. |
| * See also cpuset_zone_allowed() comment in kernel/cpuset.c. |
| */ |
| for_each_zone_zonelist_nodemask(zone, z, zonelist, |
| high_zoneidx, nodemask) { |
| if (NUMA_BUILD && zlc_active && |
| !zlc_zone_worth_trying(zonelist, z, allowednodes)) |
| continue; |
| if ((alloc_flags & ALLOC_CPUSET) && |
| !cpuset_zone_allowed_softwall(zone, gfp_mask)) |
| 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 ((alloc_flags & ALLOC_WMARK_LOW) && |
| (gfp_mask & __GFP_WRITE) && !zone_dirty_ok(zone)) |
| goto this_zone_full; |
| |
| BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK); |
| if (!(alloc_flags & ALLOC_NO_WATERMARKS)) { |
| unsigned long mark; |
| int ret; |
| |
| mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK]; |
| if (zone_watermark_ok(zone, order, mark, |
| classzone_idx, alloc_flags)) |
| goto try_this_zone; |
| |
| if (NUMA_BUILD && !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) |
| goto this_zone_full; |
| |
| /* |
| * As we may have just activated ZLC, check if the first |
| * eligible zone has failed zone_reclaim recently. |
| */ |
| if (NUMA_BUILD && 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, |
| classzone_idx, alloc_flags)) |
| goto this_zone_full; |
| } |
| } |
| |
| try_this_zone: |
| page = buffered_rmqueue(preferred_zone, zone, order, |
| gfp_mask, migratetype); |
| if (page) |
| break; |
| this_zone_full: |
| if (NUMA_BUILD) |
| zlc_mark_zone_full(zonelist, z); |
| } |
| |
| if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) { |
| /* Disable zlc cache for second zonelist scan */ |
| zlc_active = 0; |
| goto zonelist_scan; |
| } |
| return page; |
| } |
| |
| /* |
| * 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, |
| struct zonelist *zonelist, enum zone_type high_zoneidx, |
| nodemask_t *nodemask, struct zone *preferred_zone, |
| int migratetype) |
| { |
| struct page *page; |
| |
| /* Acquire the OOM killer lock for the zones in zonelist */ |
| if (!try_set_zonelist_oom(zonelist, gfp_mask)) { |
| 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, nodemask, |
| order, zonelist, high_zoneidx, |
| ALLOC_WMARK_HIGH|ALLOC_CPUSET, |
| preferred_zone, migratetype); |
| if (page) |
| goto out; |
| |
| if (!(gfp_mask & __GFP_NOFAIL)) { |
| /* 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 (high_zoneidx < ZONE_NORMAL) |
| goto out; |
| /* |
| * GFP_THISNODE contains __GFP_NORETRY and we never hit this. |
| * Sanity check for bare calls of __GFP_THISNODE, not real OOM. |
| * The caller should handle page allocation failure by itself if |
| * it specifies __GFP_THISNODE. |
| * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER. |
| */ |
| if (gfp_mask & __GFP_THISNODE) |
| goto out; |
| } |
| /* Exhausted what can be done so it's blamo time */ |
| out_of_memory(zonelist, gfp_mask, order, nodemask); |
| |
| out: |
| clear_zonelist_oom(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, |
| struct zonelist *zonelist, enum zone_type high_zoneidx, |
| nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone, |
| int migratetype, bool sync_migration, |
| bool *deferred_compaction, |
| unsigned long *did_some_progress) |
| { |
| struct page *page; |
| |
| if (!order) |
| return NULL; |
| |
| if (compaction_deferred(preferred_zone)) { |
| *deferred_compaction = true; |
| return NULL; |
| } |
| |
| current->flags |= PF_MEMALLOC; |
| *did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask, |
| nodemask, sync_migration); |
| current->flags &= ~PF_MEMALLOC; |
| if (*did_some_progress != COMPACT_SKIPPED) { |
| |
| /* Page migration frees to the PCP lists but we want merging */ |
| drain_pages(get_cpu()); |
| put_cpu(); |
| |
| page = get_page_from_freelist(gfp_mask, nodemask, |
| order, zonelist, high_zoneidx, |
| alloc_flags, preferred_zone, |
| migratetype); |
| if (page) { |
| preferred_zone->compact_considered = 0; |
| preferred_zone->compact_defer_shift = 0; |
| 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); |
| |
| /* |
| * As async compaction considers a subset of pageblocks, only |
| * defer if the failure was a sync compaction failure. |
| */ |
| if (sync_migration) |
| defer_compaction(preferred_zone); |
| |
| cond_resched(); |
| } |
| |
| return NULL; |
| } |
| #else |
| static inline struct page * |
| __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, |
| struct zonelist *zonelist, enum zone_type high_zoneidx, |
| nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone, |
| int migratetype, bool sync_migration, |
| bool *deferred_compaction, |
| unsigned long *did_some_progress) |
| { |
| return NULL; |
| } |
| #endif /* CONFIG_COMPACTION */ |
| |
| /* 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, |
| struct zonelist *zonelist, enum zone_type high_zoneidx, |
| nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone, |
| int migratetype, unsigned long *did_some_progress) |
| { |
| struct page *page = NULL; |
| struct reclaim_state reclaim_state; |
| bool drained = false; |
| |
| 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; |
| |
| *did_some_progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask); |
| |
| current->reclaim_state = NULL; |
| lockdep_clear_current_reclaim_state(); |
| current->flags &= ~PF_MEMALLOC; |
| |
| cond_resched(); |
| |
| if (unlikely(!(*did_some_progress))) |
| return NULL; |
| |
| /* After successful reclaim, reconsider all zones for allocation */ |
| if (NUMA_BUILD) |
| zlc_clear_zones_full(zonelist); |
| |
| retry: |
| page = get_page_from_freelist(gfp_mask, nodemask, order, |
| zonelist, high_zoneidx, |
| alloc_flags, preferred_zone, |
| migratetype); |
| |
| /* |
| * 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(); |
| 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, |
| struct zonelist *zonelist, enum zone_type high_zoneidx, |
| nodemask_t *nodemask, struct zone *preferred_zone, |
| int migratetype) |
| { |
| struct page *page; |
| |
| do { |
| page = get_page_from_freelist(gfp_mask, nodemask, order, |
| zonelist, high_zoneidx, ALLOC_NO_WATERMARKS, |
| preferred_zone, migratetype); |
| |
| if (!page && gfp_mask & __GFP_NOFAIL) |
| wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50); |
| } while (!page && (gfp_mask & __GFP_NOFAIL)); |
| |
| return page; |
| } |
| |
| static inline |
| void wake_all_kswapd(unsigned int order, struct zonelist *zonelist, |
| enum zone_type high_zoneidx, |
| enum zone_type classzone_idx) |
| { |
| struct zoneref *z; |
| struct zone *zone; |
| |
| for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) |
| wakeup_kswapd(zone, order, classzone_idx); |
| } |
| |
| static inline int |
| gfp_to_alloc_flags(gfp_t gfp_mask) |
| { |
| int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET; |
| const gfp_t wait = gfp_mask & __GFP_WAIT; |
| |
| /* __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 (!wait) and ALLOC_HIGH (__GFP_HIGH). |
| */ |
| alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH); |
| |
| if (!wait) { |
| /* |
| * 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 if GFP_ATOMIC (!wait) rather than fail alloc. |
| * See also cpuset_zone_allowed() comment in kernel/cpuset.c. |
| */ |
| alloc_flags &= ~ALLOC_CPUSET; |
| } else if (unlikely(rt_task(current)) && !in_interrupt()) |
| alloc_flags |= ALLOC_HARDER; |
| |
| if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) { |
| if (!in_interrupt() && |
| ((current->flags & PF_MEMALLOC) || |
| unlikely(test_thread_flag(TIF_MEMDIE)))) |
| alloc_flags |= ALLOC_NO_WATERMARKS; |
| } |
| |
| return alloc_flags; |
| } |
| |
| static inline struct page * |
| __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, |
| struct zonelist *zonelist, enum zone_type high_zoneidx, |
| nodemask_t *nodemask, struct zone *preferred_zone, |
| int migratetype) |
| { |
| 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; |
| bool sync_migration = false; |
| bool deferred_compaction = false; |
| |
| /* |
| * 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; |
| } |
| |
| /* |
| * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and |
| * __GFP_NOWARN set) should not cause reclaim since the subsystem |
| * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim |
| * using a larger set of nodes after it has established that the |
| * allowed per node queues are empty and that nodes are |
| * over allocated. |
| */ |
| if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE) |
| goto nopage; |
| |
| restart: |
| if (!(gfp_mask & __GFP_NO_KSWAPD)) |
| wake_all_kswapd(order, zonelist, high_zoneidx, |
| zone_idx(preferred_zone)); |
| |
| /* |
| * 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) && !nodemask) |
| first_zones_zonelist(zonelist, high_zoneidx, NULL, |
| &preferred_zone); |
| |
| rebalance: |
| /* This is the last chance, in general, before the goto nopage. */ |
| page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist, |
| high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS, |
| preferred_zone, migratetype); |
| if (page) |
| goto got_pg; |
| |
| /* Allocate without watermarks if the context allows */ |
| if (alloc_flags & ALLOC_NO_WATERMARKS) { |
| page = __alloc_pages_high_priority(gfp_mask, order, |
| zonelist, high_zoneidx, nodemask, |
| preferred_zone, migratetype); |
| if (page) |
| goto got_pg; |
| } |
| |
| /* Atomic allocations - we can't balance anything */ |
| if (!wait) |
| 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, |
| zonelist, high_zoneidx, |
| nodemask, |
| alloc_flags, preferred_zone, |
| migratetype, sync_migration, |
| &deferred_compaction, |
| &did_some_progress); |
| if (page) |
| goto got_pg; |
| sync_migration = true; |
| |
| /* |
| * If compaction is deferred for high-order allocations, it is because |
| * sync compaction recently failed. In this is the case and the caller |
| * has requested the system not be heavily disrupted, fail the |
| * allocation now instead of entering direct reclaim |
| */ |
| if (deferred_compaction && (gfp_mask & __GFP_NO_KSWAPD)) |
| goto nopage; |
| |
| /* Try direct reclaim and then allocating */ |
| page = __alloc_pages_direct_reclaim(gfp_mask, order, |
| zonelist, high_zoneidx, |
| nodemask, |
| alloc_flags, preferred_zone, |
| migratetype, &did_some_progress); |
| if (page) |
| goto got_pg; |
| |
| /* |
| * If we failed to make any progress reclaiming, then we are |
| * running out of options and have to consider going OOM |
| */ |
| if (!did_some_progress) { |
| if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) { |
| if (oom_killer_disabled) |
| goto nopage; |
| page = __alloc_pages_may_oom(gfp_mask, order, |
| zonelist, high_zoneidx, |
| nodemask, preferred_zone, |
| migratetype); |
| if (page) |
| goto got_pg; |
| |
| if (!(gfp_mask & __GFP_NOFAIL)) { |
| /* |
| * The oom killer is not called for high-order |
| * allocations that may fail, so if no progress |
| * is being made, there are no other options and |
| * retrying is unlikely to help. |
| */ |
| if (order > PAGE_ALLOC_COSTLY_ORDER) |
| goto nopage; |
| /* |
| * The oom killer is not called for lowmem |
| * allocations to prevent needlessly killing |
| * innocent tasks. |
| */ |
| if (high_zoneidx < ZONE_NORMAL) |
| goto nopage; |
| } |
| |
| goto restart; |
| } |
| } |
| |
| /* Check if we should retry the allocation */ |
| pages_reclaimed += did_some_progress; |
| if (should_alloc_retry(gfp_mask, order, did_some_progress, |
| pages_reclaimed)) { |
| /* Wait for some write requests to complete then retry */ |
| wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50); |
| goto rebalance; |
| } 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, |
| zonelist, high_zoneidx, |
| nodemask, |
| alloc_flags, preferred_zone, |
| migratetype, sync_migration, |
| &deferred_compaction, |
| &did_some_progress); |
| if (page) |
| goto got_pg; |
| } |
| |
| nopage: |
| warn_alloc_failed(gfp_mask, order, NULL); |
| return page; |
| got_pg: |
| if (kmemcheck_enabled) |
| kmemcheck_pagealloc_alloc(page, order, gfp_mask); |
| 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) |
| { |
| enum zone_type high_zoneidx = gfp_zone(gfp_mask); |
| struct zone *preferred_zone; |
| struct page *page; |
| int migratetype = allocflags_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; |
| |
| get_mems_allowed(); |
| /* The preferred zone is used for statistics later */ |
| first_zones_zonelist(zonelist, high_zoneidx, |
| nodemask ? : &cpuset_current_mems_allowed, |
| &preferred_zone); |
| if (!preferred_zone) { |
| put_mems_allowed(); |
| return NULL; |
| } |
| |
| /* First allocation attempt */ |
| page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order, |
| zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET, |
| preferred_zone, migratetype); |
| if (unlikely(!page)) |
| page = __alloc_pages_slowpath(gfp_mask, order, |
| zonelist, high_zoneidx, nodemask, |
| preferred_zone, migratetype); |
| put_mems_allowed(); |
| |
| trace_mm_page_alloc(page, order, gfp_mask, migratetype); |
| 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, 0); |
| 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); |
| |
| 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 *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); |
| } |
| EXPORT_SYMBOL(alloc_pages_exact_nid); |
| |
| /** |
| * 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); |
| |
| static unsigned int nr_free_zone_pages(int offset) |
| { |
| struct zoneref *z; |
| struct zone *zone; |
| |
| /* Just pick one node, since fallback list is circular */ |
| unsigned int sum = 0; |
| |
| struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL); |
| |
| for_each_zone_zonelist(zone, z, zonelist, offset) { |
| unsigned long size = zone->present_pages; |
| unsigned long high = high_wmark_pages(zone); |
| if (size > high) |
| sum += size - high; |
| } |
| |
| return sum; |
| } |
| |
| /* |
| * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL |
| */ |
| unsigned int nr_free_buffer_pages(void) |
| { |
| return nr_free_zone_pages(gfp_zone(GFP_USER)); |
| } |
| EXPORT_SYMBOL_GPL(nr_free_buffer_pages); |
| |
| /* |
| * Amount of free RAM allocatable within all zones |
| */ |
| unsigned int nr_free_pagecache_pages(void) |
| { |
| return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE)); |
| } |
| |
| static inline void show_node(struct zone *zone) |
| { |
| if (NUMA_BUILD) |
| printk("Node %d ", zone_to_nid(zone)); |
| } |
| |
| void si_meminfo(struct sysinfo *val) |
| { |
| val->totalram = totalram_pages; |
| val->sharedram = 0; |
| 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) |
| { |
| pg_data_t *pgdat = NODE_DATA(nid); |
| |
| val->totalram = pgdat->node_present_pages; |
| val->freeram = node_page_state(nid, NR_FREE_PAGES); |
| #ifdef CONFIG_HIGHMEM |
| val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_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; |
| |
| if (!(flags & SHOW_MEM_FILTER_NODES)) |
| goto out; |
| |
| get_mems_allowed(); |
| ret = !node_isset(nid, cpuset_current_mems_allowed); |
| put_mems_allowed(); |
| out: |
| return ret; |
| } |
| |
| #define K(x) ((x) << (PAGE_SHIFT-10)) |
| |
| /* |
| * 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. |
| * Suppresses nodes that are not allowed by current's cpuset if |
| * SHOW_MEM_FILTER_NODES is passed. |
| */ |
| void show_free_areas(unsigned int filter) |
| { |
| int cpu; |
| struct zone *zone; |
| |
| for_each_populated_zone(zone) { |
| if (skip_free_areas_node(filter, zone_to_nid(zone))) |
| continue; |
| show_node(zone); |
| printk("%s per-cpu:\n", zone->name); |
| |
| for_each_online_cpu(cpu) { |
| struct per_cpu_pageset *pageset; |
| |
| pageset = per_cpu_ptr(zone->pageset, cpu); |
| |
| printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n", |
| cpu, pageset->pcp.high, |
| pageset->pcp.batch, pageset->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" |
| " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n" |
| " mapped:%lu shmem:%lu pagetables:%lu bounce:%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_FREE_PAGES), |
| 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)); |
| |
| for_each_populated_zone(zone) { |
| int i; |
| |
| if (skip_free_areas_node(filter, zone_to_nid(zone))) |
| continue; |
| 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" |
| " 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" |
| " 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_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(zone_page_state(zone, NR_WRITEBACK_TEMP)), |
| zone->pages_scanned, |
| (zone->all_unreclaimable ? "yes" : "no") |
| ); |
| printk("lowmem_reserve[]:"); |
| for (i = 0; i < MAX_NR_ZONES; i++) |
| printk(" %lu", zone->lowmem_reserve[i]); |
| printk("\n"); |
| } |
| |
| for_each_populated_zone(zone) { |
| unsigned long nr[MAX_ORDER], flags, order, total = 0; |
| |
| 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++) { |
| nr[order] = zone->free_area[order].nr_free; |
| total += nr[order] << order; |
| } |
| spin_unlock_irqrestore(&zone->lock, flags); |
| for (order = 0; order < MAX_ORDER; order++) |
| printk("%lu*%lukB ", nr[order], K(1UL) << order); |
| printk("= %lukB\n", K(total)); |
| } |
| |
| 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, enum zone_type zone_type) |
| { |
| struct zone *zone; |
| |
| BUG_ON(zone_type >= MAX_NR_ZONES); |
| zone_type++; |
| |
| 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(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) |
| 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; |
| if (__parse_numa_zonelist_order((char*)table->data)) { |
| /* |
| * 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); |
| 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 = -1; |
| 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_HIGH_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, |
| MAX_NR_ZONES - 1); |
| 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, MAX_NR_ZONES - 1); |
| 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; |
| } |
| |
| static int default_zonelist_order(void) |
| { |
| int nid, zone_type; |
| unsigned long low_kmem_size,total_size; |
| struct zone *z; |
| int average_size; |
| /* |
| * ZONE_DMA and ZONE_DMA32 can be very small area in the system. |
| * If they are really small and used heavily, the system can fall |
| * into OOM very easily. |
| * This function detect ZONE_DMA/DMA32 size and configures zone order. |
| */ |
| /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */ |
| low_kmem_size = 0; |
| total_size = 0; |
| for_each_online_node(nid) { |
| for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { |
| z = &NODE_DATA(nid)->node_zones[zone_type]; |
| if (populated_zone(z)) { |
| if (zone_type < ZONE_NORMAL) |
| low_kmem_size += z->present_pages; |
| total_size += z->present_pages; |
| } else if (zone_type == ZONE_NORMAL) { |
| /* |
| * If any node has only lowmem, then node order |
| * is preferred to allow kernel allocations |
| * locally; otherwise, they can easily infringe |
| * on other nodes when there is an abundance of |
| * lowmem available to allocate from. |
| */ |
| return ZONELIST_ORDER_NODE; |
| } |
| } |
| } |
| if (!low_kmem_size || /* there are no DMA area. */ |
| low_kmem_size > total_size/2) /* DMA/DMA32 is big. */ |
| return ZONELIST_ORDER_NODE; |
| /* |
| * look into each node's config. |
| * If there is a node whose DMA/DMA32 memory is very big area on |
| * local memory, NODE_ORDER may be suitable. |
| */ |
| average_size = total_size / |
| (nodes_weight(node_states[N_HIGH_MEMORY]) + 1); |
| for_each_online_node(nid) { |
| low_kmem_size = 0; |
| total_size = 0; |
| for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { |
| z = &NODE_DATA(nid)->node_zones[zone_type]; |
| if (populated_zone(z)) { |
| if (zone_type < ZONE_NORMAL) |
| low_kmem_size += z->present_pages; |
| total_size += z->present_pages; |
| } |
| } |
| if (low_kmem_size && |
| total_size > average_size && /* ignore small node */ |
| low_kmem_size > total_size * 70/100) |
| return ZONELIST_ORDER_NODE; |
| } |
| return ZONELIST_ORDER_ZONE; |
| } |
| |
| 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) { |
| int distance = node_distance(local_node, node); |
| |
| /* |
| * If another node is sufficiently far away then it is better |
| * to reclaim pages in a zone before going off node. |
| */ |
| if (distance > RECLAIM_DISTANCE) |
| zone_reclaim_mode = 1; |
| |
| /* |
| * 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 (distance != 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, MAX_NR_ZONES - 1); |
| |
| /* |
| * 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; |
|