diff options
Diffstat (limited to 'linux-2.6-xen-sparse/mm/page_alloc.c')
| -rw-r--r-- | linux-2.6-xen-sparse/mm/page_alloc.c | 2481 |
1 files changed, 0 insertions, 2481 deletions
diff --git a/linux-2.6-xen-sparse/mm/page_alloc.c b/linux-2.6-xen-sparse/mm/page_alloc.c deleted file mode 100644 index b0a813a4f6..0000000000 --- a/linux-2.6-xen-sparse/mm/page_alloc.c +++ /dev/null @@ -1,2481 +0,0 @@ -/* - * 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/bootmem.h> -#include <linux/compiler.h> -#include <linux/kernel.h> -#include <linux/module.h> -#include <linux/suspend.h> -#include <linux/pagevec.h> -#include <linux/blkdev.h> -#include <linux/slab.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/mempolicy.h> -#include <linux/stop_machine.h> - -#include <asm/tlbflush.h> -#include <asm/div64.h> -#include "internal.h" - -/* - * MCD - HACK: Find somewhere to initialize this EARLY, or make this - * initializer cleaner - */ -nodemask_t node_online_map __read_mostly = { { [0] = 1UL } }; -EXPORT_SYMBOL(node_online_map); -nodemask_t node_possible_map __read_mostly = NODE_MASK_ALL; -EXPORT_SYMBOL(node_possible_map); -unsigned long totalram_pages __read_mostly; -unsigned long totalhigh_pages __read_mostly; -unsigned long totalreserve_pages __read_mostly; -long nr_swap_pages; -int percpu_pagelist_fraction; - -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] = { 256, 256, 32 }; - -EXPORT_SYMBOL(totalram_pages); - -/* - * Used by page_zone() to look up the address of the struct zone whose - * id is encoded in the upper bits of page->flags - */ -struct zone *zone_table[1 << ZONETABLE_SHIFT] __read_mostly; -EXPORT_SYMBOL(zone_table); - -static char *zone_names[MAX_NR_ZONES] = { "DMA", "DMA32", "Normal", "HighMem" }; -int min_free_kbytes = 1024; - -unsigned long __meminitdata nr_kernel_pages; -unsigned long __meminitdata nr_all_pages; - -#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) -{ -#ifdef CONFIG_HOLES_IN_ZONE - if (!pfn_valid(page_to_pfn(page))) - return 0; -#endif - 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) -{ - printk(KERN_EMERG "Bad page state in process '%s'\n" - KERN_EMERG "page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n" - KERN_EMERG "Trying to fix it up, but a reboot is needed\n" - KERN_EMERG "Backtrace:\n", - current->comm, page, (int)(2*sizeof(unsigned long)), - (unsigned long)page->flags, page->mapping, - page_mapcount(page), page_count(page)); - dump_stack(); - page->flags &= ~(1 << PG_lru | - 1 << PG_private | - 1 << PG_locked | - 1 << PG_active | - 1 << PG_dirty | - 1 << PG_reclaim | - 1 << PG_slab | - 1 << PG_swapcache | - 1 << PG_writeback | - 1 << PG_buddy | -#ifdef CONFIG_X86_XEN - 1 << PG_pinned | -#endif - 1 << PG_foreign ); - set_page_count(page, 0); - reset_page_mapcount(page); - page->mapping = NULL; - 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 pages have their ->private pointing at - * the head page (even the head page has this). - * - * 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, (unsigned long)page[1].lru.prev); -} - -static void prep_compound_page(struct page *page, unsigned long order) -{ - int i; - int nr_pages = 1 << order; - - page[1].lru.next = (void *)free_compound_page; /* set dtor */ - page[1].lru.prev = (void *)order; - for (i = 0; i < nr_pages; i++) { - struct page *p = page + i; - - __SetPageCompound(p); - set_page_private(p, (unsigned long)page); - } -} - -static void destroy_compound_page(struct page *page, unsigned long order) -{ - int i; - int nr_pages = 1 << order; - - if (unlikely((unsigned long)page[1].lru.prev != order)) - bad_page(page); - - for (i = 0; i < nr_pages; i++) { - struct page *p = page + i; - - if (unlikely(!PageCompound(p) | - (page_private(p) != (unsigned long)page))) - bad_page(page); - __ClearPageCompound(p); - } -} - -static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags) -{ - int i; - - BUG_ON((gfp_flags & (__GFP_WAIT | __GFP_HIGHMEM)) == __GFP_HIGHMEM); - /* - * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO - * and __GFP_HIGHMEM from hard or soft interrupt context. - */ - BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt()); - for (i = 0; i < (1 << order); i++) - clear_highpage(page + i); -} - -/* - * function for dealing with page's order in buddy system. - * zone->lock is already acquired when we use these. - * So, we don't need atomic page->flags operations here. - */ -static inline unsigned long page_order(struct page *page) -{ - return page_private(page); -} - -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 struct page * -__page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order) -{ - unsigned long buddy_idx = page_idx ^ (1 << order); - - return page + (buddy_idx - page_idx); -} - -static inline unsigned long -__find_combined_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 use PG_buddy. - * Setting, clearing, and testing PG_buddy 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) -{ -#ifdef CONFIG_HOLES_IN_ZONE - if (!pfn_valid(page_to_pfn(buddy))) - return 0; -#endif - - if (page_zone_id(page) != page_zone_id(buddy)) - return 0; - - if (PageBuddy(buddy) && page_order(buddy) == order) { - 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 PG_buddy. 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) -{ - unsigned long page_idx; - int order_size = 1 << order; - - if (unlikely(PageCompound(page))) - destroy_compound_page(page, order); - - page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1); - - BUG_ON(page_idx & (order_size - 1)); - BUG_ON(bad_range(zone, page)); - - zone->free_pages += order_size; - while (order < MAX_ORDER-1) { - unsigned long combined_idx; - struct free_area *area; - struct page *buddy; - - buddy = __page_find_buddy(page, page_idx, order); - if (!page_is_buddy(page, buddy, order)) - break; /* Move the buddy up one level. */ - - list_del(&buddy->lru); - area = zone->free_area + order; - area->nr_free--; - rmv_page_order(buddy); - combined_idx = __find_combined_index(page_idx, order); - page = page + (combined_idx - page_idx); - page_idx = combined_idx; - order++; - } - set_page_order(page, order); - list_add(&page->lru, &zone->free_area[order].free_list); - zone->free_area[order].nr_free++; -} - -static inline int free_pages_check(struct page *page) -{ - if (unlikely(page_mapcount(page) | - (page->mapping != NULL) | - (page_count(page) != 0) | - (page->flags & ( - 1 << PG_lru | - 1 << PG_private | - 1 << PG_locked | - 1 << PG_active | - 1 << PG_reclaim | - 1 << PG_slab | - 1 << PG_swapcache | - 1 << PG_writeback | - 1 << PG_reserved | - 1 << PG_buddy | -#ifdef CONFIG_X86_XEN - 1 << PG_pinned | -#endif - 1 << PG_foreign )))) - bad_page(page); - if (PageDirty(page)) - __ClearPageDirty(page); - /* - * For now, we report if PG_reserved was found set, but do not - * clear it, and do not free the page. But we shall soon need - * to do more, for when the ZERO_PAGE count wraps negative. - */ - return PageReserved(page); -} - -/* - * Frees a list of pages. - * 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_pages_bulk(struct zone *zone, int count, - struct list_head *list, int order) -{ - spin_lock(&zone->lock); - zone->all_unreclaimable = 0; - zone->pages_scanned = 0; - while (count--) { - struct page *page; - - BUG_ON(list_empty(list)); - page = list_entry(list->prev, struct page, lru); - /* have to delete it as __free_one_page list manipulates */ - list_del(&page->lru); - __free_one_page(page, zone, order); - } - spin_unlock(&zone->lock); -} - -static void free_one_page(struct zone *zone, struct page *page, int order) -{ - LIST_HEAD(list); - list_add(&page->lru, &list); - free_pages_bulk(zone, 1, &list, order); -} - -static void __free_pages_ok(struct page *page, unsigned int order) -{ - unsigned long flags; - int i; - int reserved = 0; - - if (arch_free_page(page, order)) - return; - if (!PageHighMem(page)) - debug_check_no_locks_freed(page_address(page), - PAGE_SIZE<<order); - - for (i = 0 ; i < (1 << order) ; ++i) - reserved += free_pages_check(page + i); - if (reserved) - return; - - kernel_map_pages(page, 1 << order, 0); - local_irq_save(flags); - __count_vm_events(PGFREE, 1 << order); - free_one_page(page_zone(page), page, order); - local_irq_restore(flags); -} - -/* - * permit the bootmem allocator to evade page validation on high-order frees - */ -void fastcall __init __free_pages_bootmem(struct page *page, unsigned int order) -{ - if (order == 0) { - __ClearPageReserved(page); - set_page_count(page, 0); - set_page_refcounted(page); - __free_page(page); - } else { - int loop; - - prefetchw(page); - for (loop = 0; loop < BITS_PER_LONG; loop++) { - struct page *p = &page[loop]; - - if (loop + 1 < BITS_PER_LONG) - 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) -{ - unsigned long size = 1 << high; - - while (high > low) { - area--; - high--; - size >>= 1; - BUG_ON(bad_range(zone, &page[size])); - list_add(&page[size].lru, &area->free_list); - area->nr_free++; - set_page_order(&page[size], high); - } -} - -/* - * This page is about to be returned from the page allocator - */ -static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) -{ - if (unlikely(page_mapcount(page) | - (page->mapping != NULL) | - (page_count(page) != 0) | - (page->flags & ( - 1 << PG_lru | - 1 << PG_private | - 1 << PG_locked | - 1 << PG_active | - 1 << PG_dirty | - 1 << PG_reclaim | - 1 << PG_slab | - 1 << PG_swapcache | - 1 << PG_writeback | - 1 << PG_reserved | - 1 << PG_buddy | -#ifdef CONFIG_X86_XEN - 1 << PG_pinned | -#endif - 1 << PG_foreign )))) - bad_page(page); - - /* - * For now, we report if PG_reserved was found set, but do not - * clear it, and do not allocate the page: as a safety net. - */ - if (PageReserved(page)) - return 1; - - page->flags &= ~(1 << PG_uptodate | 1 << PG_error | - 1 << PG_referenced | 1 << PG_arch_1 | - 1 << PG_checked | 1 << PG_mappedtodisk); - set_page_private(page, 0); - set_page_refcounted(page); - 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; -} - -/* - * 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) -{ - struct free_area * area; - unsigned int current_order; - struct page *page; - - for (current_order = order; current_order < MAX_ORDER; ++current_order) { - area = zone->free_area + current_order; - if (list_empty(&area->free_list)) - continue; - - page = list_entry(area->free_list.next, struct page, lru); - list_del(&page->lru); - rmv_page_order(page); - area->nr_free--; - zone->free_pages -= 1UL << order; - expand(zone, page, order, current_order, area); - return page; - } - - return NULL; -} - -/* - * 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 i; - - spin_lock(&zone->lock); - for (i = 0; i < count; ++i) { - struct page *page = __rmqueue(zone, order); - if (unlikely(page == NULL)) - break; - list_add_tail(&page->lru, list); - } - spin_unlock(&zone->lock); - return i; -} - -#ifdef CONFIG_NUMA -/* - * Called from the slab reaper to drain pagesets on a particular node that - * belong to the currently executing processor. - * Note that this function must be called with the thread pinned to - * a single processor. - */ -void drain_node_pages(int nodeid) -{ - int i, z; - unsigned long flags; - - for (z = 0; z < MAX_NR_ZONES; z++) { - struct zone *zone = NODE_DATA(nodeid)->node_zones + z; - struct per_cpu_pageset *pset; - - pset = zone_pcp(zone, smp_processor_id()); - for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) { - struct per_cpu_pages *pcp; - - pcp = &pset->pcp[i]; - if (pcp->count) { - local_irq_save(flags); - free_pages_bulk(zone, pcp->count, &pcp->list, 0); - pcp->count = 0; - local_irq_restore(flags); - } - } - } -} -#endif - -#if defined(CONFIG_PM) || defined(CONFIG_HOTPLUG_CPU) -static void __drain_pages(unsigned int cpu) -{ - unsigned long flags; - struct zone *zone; - int i; - - for_each_zone(zone) { - struct per_cpu_pageset *pset; - - pset = zone_pcp(zone, cpu); - for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) { - struct per_cpu_pages *pcp; - - pcp = &pset->pcp[i]; - local_irq_save(flags); - free_pages_bulk(zone, pcp->count, &pcp->list, 0); - pcp->count = 0; - local_irq_restore(flags); - } - } -} -#endif /* CONFIG_PM || CONFIG_HOTPLUG_CPU */ - -#ifdef CONFIG_PM - -void mark_free_pages(struct zone *zone) -{ - unsigned long zone_pfn, flags; - int order; - struct list_head *curr; - - if (!zone->spanned_pages) - return; - - spin_lock_irqsave(&zone->lock, flags); - for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) - ClearPageNosaveFree(pfn_to_page(zone_pfn + zone->zone_start_pfn)); - - for (order = MAX_ORDER - 1; order >= 0; --order) - list_for_each(curr, &zone->free_area[order].free_list) { - unsigned long start_pfn, i; - - start_pfn = page_to_pfn(list_entry(curr, struct page, lru)); - - for (i=0; i < (1<<order); i++) - SetPageNosaveFree(pfn_to_page(start_pfn+i)); - } - spin_unlock_irqrestore(&zone->lock, flags); -} - -/* - * Spill all of this CPU's per-cpu pages back into the buddy allocator. - */ -void drain_local_pages(void) -{ - unsigned long flags; - - local_irq_save(flags); - __drain_pages(smp_processor_id()); - local_irq_restore(flags); -} -#endif /* CONFIG_PM */ - -/* - * Free a 0-order page - */ -static void fastcall free_hot_cold_page(struct page *page, int cold) -{ - struct zone *zone = page_zone(page); - struct per_cpu_pages *pcp; - unsigned long flags; - - if (arch_free_page(page, 0)) - return; - - if (PageAnon(page)) - page->mapping = NULL; - if (free_pages_check(page)) - return; - - kernel_map_pages(page, 1, 0); - - pcp = &zone_pcp(zone, get_cpu())->pcp[cold]; - local_irq_save(flags); - __count_vm_event(PGFREE); - list_add(&page->lru, &pcp->list); - pcp->count++; - if (pcp->count >= pcp->high) { - free_pages_bulk(zone, pcp->batch, &pcp->list, 0); - pcp->count -= pcp->batch; - } - local_irq_restore(flags); - put_cpu(); -} - -void fastcall free_hot_page(struct page *page) -{ - free_hot_cold_page(page, 0); -} - -void fastcall free_cold_page(struct page *page) -{ - free_hot_cold_page(page, 1); -} - -/* - * 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; - - BUG_ON(PageCompound(page)); - BUG_ON(!page_count(page)); - for (i = 1; i < (1 << order); i++) - set_page_refcounted(page + i); -} - -/* - * 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 struct page *buffered_rmqueue(struct zonelist *zonelist, - struct zone *zone, int order, gfp_t gfp_flags) -{ - unsigned long flags; - struct page *page; - int cold = !!(gfp_flags & __GFP_COLD); - int cpu; - -again: - cpu = get_cpu(); - if (likely(order == 0)) { - struct per_cpu_pages *pcp; - - pcp = &zone_pcp(zone, cpu)->pcp[cold]; - local_irq_save(flags); - if (!pcp->count) { - pcp->count += rmqueue_bulk(zone, 0, - pcp->batch, &pcp->list); - if (unlikely(!pcp->count)) - goto failed; - } - page = list_entry(pcp->list.next, struct page, lru); - list_del(&page->lru); - pcp->count--; - } else { - spin_lock_irqsave(&zone->lock, flags); - page = __rmqueue(zone, order); - spin_unlock(&zone->lock); - if (!page) - goto failed; - } - - __count_zone_vm_events(PGALLOC, zone, 1 << order); - zone_statistics(zonelist, zone); - local_irq_restore(flags); - put_cpu(); - - BUG_ON(bad_range(zone, page)); - if (prep_new_page(page, order, gfp_flags)) - goto again; - return page; - -failed: - local_irq_restore(flags); - put_cpu(); - return NULL; -} - -#define ALLOC_NO_WATERMARKS 0x01 /* don't check watermarks at all */ -#define ALLOC_WMARK_MIN 0x02 /* use pages_min watermark */ -#define ALLOC_WMARK_LOW 0x04 /* use pages_low watermark */ -#define ALLOC_WMARK_HIGH 0x08 /* use pages_high watermark */ -#define ALLOC_HARDER 0x10 /* try to alloc harder */ -#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ -#define ALLOC_CPUSET 0x40 /* check for correct cpuset */ - -/* - * Return 1 if free pages are above 'mark'. This takes into account the order - * of the allocation. - */ -int zone_watermark_ok(struct zone *z, int order, unsigned long mark, - int classzone_idx, int alloc_flags) -{ - /* free_pages my go negative - that's OK */ - long min = mark, free_pages = z->free_pages - (1 << order) + 1; - int o; - - 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 0; - 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 0; - } - return 1; -} - -/* - * get_page_from_freeliest goes through the zonelist trying to allocate - * a page. - */ -static struct page * -get_page_from_freelist(gfp_t gfp_mask, unsigned int order, - struct zonelist *zonelist, int alloc_flags) -{ - struct zone **z = zonelist->zones; - struct page *page = NULL; - int classzone_idx = zone_idx(*z); - - /* - * Go through the zonelist once, looking for a zone with enough free. - * See also cpuset_zone_allowed() comment in kernel/cpuset.c. - */ - do { - if ((alloc_flags & ALLOC_CPUSET) && - !cpuset_zone_allowed(*z, gfp_mask)) - continue; - - if (!(alloc_flags & ALLOC_NO_WATERMARKS)) { - unsigned long mark; - if (alloc_flags & ALLOC_WMARK_MIN) - mark = (*z)->pages_min; - else if (alloc_flags & ALLOC_WMARK_LOW) - mark = (*z)->pages_low; - else - mark = (*z)->pages_high; - if (!zone_watermark_ok(*z, order, mark, - classzone_idx, alloc_flags)) - if (!zone_reclaim_mode || - !zone_reclaim(*z, gfp_mask, order)) - continue; - } - - page = buffered_rmqueue(zonelist, *z, order, gfp_mask); - if (page) { - break; - } - } while (*(++z) != NULL); - return page; -} - -/* - * This is the 'heart' of the zoned buddy allocator. - */ -struct page * fastcall -__alloc_pages(gfp_t gfp_mask, unsigned int order, - struct zonelist *zonelist) -{ - const gfp_t wait = gfp_mask & __GFP_WAIT; - struct zone **z; - struct page *page; - struct reclaim_state reclaim_state; - struct task_struct *p = current; - int do_retry; - int alloc_flags; - int did_some_progress; - - might_sleep_if(wait); - -restart: - z = zonelist->zones; /* the list of zones suitable for gfp_mask */ - - if (unlikely(*z == NULL)) { - /* Should this ever happen?? */ - return NULL; - } - - page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order, - zonelist, ALLOC_WMARK_LOW|ALLOC_CPUSET); - if (page) - goto got_pg; - - do { - wakeup_kswapd(*z, order); - } while (*(++z)); - - /* - * 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. - * - * 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 = ALLOC_WMARK_MIN; - if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait) - alloc_flags |= ALLOC_HARDER; - if (gfp_mask & __GFP_HIGH) - alloc_flags |= ALLOC_HIGH; - if (wait) - alloc_flags |= ALLOC_CPUSET; - - /* - * Go through the zonelist again. Let __GFP_HIGH and allocations - * coming from realtime tasks go deeper into reserves. - * - * This is the last chance, in general, before the goto nopage. - * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc. - * See also cpuset_zone_allowed() comment in kernel/cpuset.c. - */ - page = get_page_from_freelist(gfp_mask, order, zonelist, alloc_flags); - if (page) - goto got_pg; - - /* This allocation should allow future memory freeing. */ - - if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE))) - && !in_interrupt()) { - if (!(gfp_mask & __GFP_NOMEMALLOC)) { -nofail_alloc: - /* go through the zonelist yet again, ignoring mins */ - page = get_page_from_freelist(gfp_mask, order, - zonelist, ALLOC_NO_WATERMARKS); - if (page) - goto got_pg; - if (gfp_mask & __GFP_NOFAIL) { - blk_congestion_wait(WRITE, HZ/50); - goto nofail_alloc; - } - } - goto nopage; - } - - /* Atomic allocations - we can't balance anything */ - if (!wait) - goto nopage; - -rebalance: - cond_resched(); - - /* We now go into synchronous reclaim */ - cpuset_memory_pressure_bump(); - p->flags |= PF_MEMALLOC; - reclaim_state.reclaimed_slab = 0; - p->reclaim_state = &reclaim_state; - - did_some_progress = try_to_free_pages(zonelist->zones, gfp_mask); - - p->reclaim_state = NULL; - p->flags &= ~PF_MEMALLOC; - - cond_resched(); - - if (likely(did_some_progress)) { - page = get_page_from_freelist(gfp_mask, order, - zonelist, alloc_flags); - if (page) - goto got_pg; - } else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) { - /* - * Go through the zonelist yet one more time, keep - * very high watermark here, this is only to catch - * a parallel oom killing, we must fail if we're still - * under heavy pressure. - */ - page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order, - zonelist, ALLOC_WMARK_HIGH|ALLOC_CPUSET); - if (page) - goto got_pg; - - out_of_memory(zonelist, gfp_mask, order); - goto restart; - } - - /* - * Don't let big-order allocations loop unless the caller explicitly - * requests that. Wait for some write requests to complete then retry. - * - * In this implementation, __GFP_REPEAT means __GFP_NOFAIL for order - * <= 3, but that may not be true in other implementations. - */ - do_retry = 0; - if (!(gfp_mask & __GFP_NORETRY)) { - if ((order <= 3) || (gfp_mask & __GFP_REPEAT)) - do_retry = 1; - if (gfp_mask & __GFP_NOFAIL) - do_retry = 1; - } - if (do_retry) { - blk_congestion_wait(WRITE, HZ/50); - goto rebalance; - } - -nopage: - if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) { - printk(KERN_WARNING "%s: page allocation failure." - " order:%d, mode:0x%x\n", - p->comm, order, gfp_mask); - dump_stack(); - show_mem(); - } -got_pg: - return page; -} - -EXPORT_SYMBOL(__alloc_pages); - -/* - * Common helper functions. - */ -fastcall unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) -{ - struct page * page; - page = alloc_pages(gfp_mask, order); - if (!page) - return 0; - return (unsigned long) page_address(page); -} - -EXPORT_SYMBOL(__get_free_pages); - -fastcall unsigned long get_zeroed_page(gfp_t gfp_mask) -{ - struct page * page; - - /* - * get_zeroed_page() returns a 32-bit address, which cannot represent - * a highmem page - */ - BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0); - - page = alloc_pages(gfp_mask | __GFP_ZERO, 0); - if (page) - return (unsigned long) page_address(page); - return 0; -} - -EXPORT_SYMBOL(get_zeroed_page); - -void __pagevec_free(struct pagevec *pvec) -{ - int i = pagevec_count(pvec); - - while (--i >= 0) - free_hot_cold_page(pvec->pages[i], pvec->cold); -} - -fastcall void __free_pages(struct page *page, unsigned int order) -{ - if (put_page_testzero(page)) { - if (order == 0) - free_hot_page(page); - else - __free_pages_ok(page, order); - } -} - -EXPORT_SYMBOL(__free_pages); - -fastcall void free_pages(unsigned long addr, unsigned int order) -{ - if (addr != 0) { - BUG_ON(!virt_addr_valid((void *)addr)); - __free_pages(virt_to_page((void *)addr), order); - } -} - -EXPORT_SYMBOL(free_pages); - -/* - * Total amount of free (allocatable) RAM: - */ -unsigned int nr_free_pages(void) -{ - unsigned int sum = 0; - struct zone *zone; - - for_each_zone(zone) - sum += zone->free_pages; - - return sum; -} - -EXPORT_SYMBOL(nr_free_pages); - -#ifdef CONFIG_NUMA -unsigned int nr_free_pages_pgdat(pg_data_t *pgdat) -{ - unsigned int i, sum = 0; - - for (i = 0; i < MAX_NR_ZONES; i++) - sum += pgdat->node_zones[i].free_pages; - - return sum; -} -#endif - -static unsigned int nr_free_zone_pages(int offset) -{ - /* Just pick one node, since fallback list is circular */ - pg_data_t *pgdat = NODE_DATA(numa_node_id()); - unsigned int sum = 0; - - struct zonelist *zonelist = pgdat->node_zonelists + offset; - struct zone **zonep = zonelist->zones; - struct zone *zone; - - for (zone = *zonep++; zone; zone = *zonep++) { - unsigned long size = zone->present_pages; - unsigned long high = zone->pages_high; - 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)); -} - -/* - * Amount of free RAM allocatable within all zones - */ -unsigned int nr_free_pagecache_pages(void) -{ - return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER)); -} - -#ifdef CONFIG_HIGHMEM -unsigned int nr_free_highpages (void) -{ - pg_data_t *pgdat; - unsigned int pages = 0; - - for_each_online_pgdat(pgdat) - pages += pgdat->node_zones[ZONE_HIGHMEM].free_pages; - - return pages; -} -#endif - -#ifdef CONFIG_NUMA -static void show_node(struct zone *zone) -{ - printk("Node %d ", zone->zone_pgdat->node_id); -} -#else -#define show_node(zone) do { } while (0) -#endif - -void si_meminfo(struct sysinfo *val) -{ - val->totalram = totalram_pages; - val->sharedram = 0; - val->freeram = nr_free_pages(); - val->bufferram = nr_blockdev_pages(); -#ifdef CONFIG_HIGHMEM - val->totalhigh = totalhigh_pages; - val->freehigh = nr_free_highpages(); -#else - val->totalhigh = 0; - val->freehigh = 0; -#endif - 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 = nr_free_pages_pgdat(pgdat); - val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages; - val->freehigh = pgdat->node_zones[ZONE_HIGHMEM].free_pages; - val->mem_unit = PAGE_SIZE; -} -#endif - -#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. - */ -void show_free_areas(void) -{ - int cpu, temperature; - unsigned long active; - unsigned long inactive; - unsigned long free; - struct zone *zone; - - for_each_zone(zone) { - show_node(zone); - printk("%s per-cpu:", zone->name); - - if (!populated_zone(zone)) { - printk(" empty\n"); - continue; - } else - printk("\n"); - - for_each_online_cpu(cpu) { - struct per_cpu_pageset *pageset; - - pageset = zone_pcp(zone, cpu); - - for (temperature = 0; temperature < 2; temperature++) - printk("cpu %d %s: high %d, batch %d used:%d\n", - cpu, - temperature ? "cold" : "hot", - pageset->pcp[temperature].high, - pageset->pcp[temperature].batch, - pageset->pcp[temperature].count); - } - } - - get_zone_counts(&active, &inactive, &free); - - printk("Free pages: %11ukB (%ukB HighMem)\n", - K(nr_free_pages()), - K(nr_free_highpages())); - - printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu " - "unstable:%lu free:%u slab:%lu mapped:%lu pagetables:%lu\n", - active, - inactive, - global_page_state(NR_FILE_DIRTY), - global_page_state(NR_WRITEBACK), - global_page_state(NR_UNSTABLE_NFS), - nr_free_pages(), - global_page_state(NR_SLAB), - global_page_state(NR_FILE_MAPPED), - global_page_state(NR_PAGETABLE)); - - for_each_zone(zone) { - int i; - - show_node(zone); - printk("%s" - " free:%lukB" - " min:%lukB" - " low:%lukB" - " high:%lukB" - " active:%lukB" - " inactive:%lukB" - " present:%lukB" - " pages_scanned:%lu" - " all_unreclaimable? %s" - "\n", - zone->name, - K(zone->free_pages), - K(zone->pages_min), - K(zone->pages_low), - K(zone->pages_high), - K(zone->nr_active), - K(zone->nr_inactive), - K(zone->present_pages), - 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_zone(zone) { - unsigned long nr[MAX_ORDER], flags, order, total = 0; - - show_node(zone); - printk("%s: ", zone->name); - if (!populated_zone(zone)) { - printk("empty\n"); - continue; - } - - 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)); - } - - show_swap_cache_info(); -} - -/* - * Builds allocation fallback zone lists. - * - * Add all populated zones of a node to the zonelist. - */ -static int __meminit build_zonelists_node(pg_data_t *pgdat, - struct zonelist *zonelist, int nr_zones, int zone_type) -{ - struct zone *zone; - - BUG_ON(zone_type > ZONE_HIGHMEM); - - do { - zone = pgdat->node_zones + zone_type; - if (populated_zone(zone)) { -#ifndef CONFIG_HIGHMEM - BUG_ON(zone_type > ZONE_NORMAL); -#endif - zonelist->zones[nr_zones++] = zone; - check_highest_zone(zone_type); - } - zone_type--; - - } while (zone_type >= 0); - return nr_zones; -} - -static inline int highest_zone(int zone_bits) -{ - int res = ZONE_NORMAL; - if (zone_bits & (__force int)__GFP_HIGHMEM) - res = ZONE_HIGHMEM; - if (zone_bits & (__force int)__GFP_DMA32) - res = ZONE_DMA32; - if (zone_bits & (__force int)__GFP_DMA) - res = ZONE_DMA; - return res; -} - -#ifdef CONFIG_NUMA -#define MAX_NODE_LOAD (num_online_nodes()) -static int __meminitdata 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 __meminit find_next_best_node(int node, nodemask_t *used_node_mask) -{ - int n, val; - int min_val = INT_MAX; - int best_node = -1; - - /* 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_online_node(n) { - cpumask_t tmp; - - /* 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 = node_to_cpumask(n); - if (!cpus_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; -} - -static void __meminit build_zonelists(pg_data_t *pgdat) -{ - int i, j, k, node, local_node; - int prev_node, load; - struct zonelist *zonelist; - nodemask_t used_mask; - - /* initialize zonelists */ - for (i = 0; i < GFP_ZONETYPES; i++) { - zonelist = pgdat->node_zonelists + i; - zonelist->zones[0] = NULL; - } - - /* NUMA-aware ordering of nodes */ - local_node = pgdat->node_id; - load = num_online_nodes(); - prev_node = local_node; - nodes_clear(used_mask); - 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--; - for (i = 0; i < GFP_ZONETYPES; i++) { - zonelist = pgdat->node_zonelists + i; - for (j = 0; zonelist->zones[j] != NULL; j++); - - k = highest_zone(i); - - j = build_zonelists_node(NODE_DATA(node), zonelist, j, k); - zonelist->zones[j] = NULL; - } - } -} - -#else /* CONFIG_NUMA */ - -static void __meminit build_zonelists(pg_data_t *pgdat) -{ - int i, j, k, node, local_node; - - local_node = pgdat->node_id; - for (i = 0; i < GFP_ZONETYPES; i++) { - struct zonelist *zonelist; - - zonelist = pgdat->node_zonelists + i; - - j = 0; - k = highest_zone(i); - j = build_zonelists_node(pgdat, zonelist, j, k); - /* - * Now we build the zonelist so that it contains the zones - * of all the other nodes. - * We don't want to pressure a particular node, so when - * building the zones for node N, we make sure that the - * zones coming right after the local ones are those from - * node N+1 (modulo N) - */ - for (node = local_node + 1; node < MAX_NUMNODES; node++) { - if (!node_online(node)) - continue; - j = build_zonelists_node(NODE_DATA(node), zonelist, j, k); - } - for (node = 0; node < local_node; node++) { - if (!node_online(node)) - continue; - j = build_zonelists_node(NODE_DATA(node), zonelist, j, k); - } - - zonelist->zones[j] = NULL; - } -} - -#endif /* CONFIG_NUMA */ - -/* return values int ....just for stop_machine_run() */ -static int __meminit __build_all_zonelists(void *dummy) -{ - int nid; - for_each_online_node(nid) - build_zonelists(NODE_DATA(nid)); - return 0; -} - -void __meminit build_all_zonelists(void) -{ - if (system_state == SYSTEM_BOOTING) { - __build_all_zonelists(0); - cpuset_init_current_mems_allowed(); - } else { - /* we have to stop all cpus to guaranntee there is no user - of zonelist */ - stop_machine_run(__build_all_zonelists, NULL, NR_CPUS); - /* cpuset refresh routine should be here */ - } - vm_total_pages = nr_free_pagecache_pages(); - printk("Built %i zonelists. Total pages: %ld\n", - num_online_nodes(), vm_total_pages); -} - -/* - * Helper functions to size the waitqueue hash table. - * Essentially these want to choose hash table sizes sufficiently - * large so that collisions trying to wait on pages are rare. - * But in fact, the number of active page waitqueues on typical - * systems is ridiculously low, less than 200. So this is even - * conservative, even though it seems large. - * - * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to - * waitqueues, i.e. the size of the waitq table given the number of pages. - */ -#define PAGES_PER_WAITQUEUE 256 - -#ifndef CONFIG_MEMORY_HOTPLUG -static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) -{ - unsigned long size = 1; - - pages /= PAGES_PER_WAITQUEUE; - - while (size < pages) - size <<= 1; - - /* - * Once we have dozens or even hundreds of threads sleeping - * on IO we've got bigger problems than wait queue collision. - * Limit the size of the wait table to a reasonable size. - */ - size = min(size, 4096UL); - - return max(size, 4UL); -} -#else -/* - * A zone's size might be changed by hot-add, so it is not possible to determine - * a suitable size for its wait_table. So we use the maximum size now. - * - * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie: - * - * i386 (preemption config) : 4096 x 16 = 64Kbyte. - * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte. - * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte. - * - * The maximum entries are prepared when a zone's memory is (512K + 256) pages - * or more by the traditional way. (See above). It equals: - * - * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte. - * ia64(16K page size) : = ( 8G + 4M)byte. - * powerpc (64K page size) : = (32G +16M)byte. - */ -static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) -{ - return 4096UL; -} -#endif - -/* - * This is an integer logarithm so that shifts can be used later - * to extract the more random high bits from the multiplicative - * hash function before the remainder is taken. - */ -static inline unsigned long wait_table_bits(unsigned long size) -{ - return ffz(~size); -} - -#define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1)) - -static void __init calculate_zone_totalpages(struct pglist_data *pgdat, - unsigned long *zones_size, unsigned long *zholes_size) -{ - unsigned long realtotalpages, totalpages = 0; - int i; - - for (i = 0; i < MAX_NR_ZONES; i++) - totalpages += zones_size[i]; - pgdat->node_spanned_pages = totalpages; - - realtotalpages = totalpages; - if (zholes_size) - for (i = 0; i < MAX_NR_ZONES; i++) - realtotalpages -= zholes_size[i]; - pgdat->node_present_pages = realtotalpages; - printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, realtotalpages); -} - - -/* - * Initially all pages are reserved - free ones are freed - * up by free_all_bootmem() once the early boot process is - * done. Non-atomic initialization, single-pass. - */ -void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, - unsigned long start_pfn) -{ - struct page *page; - unsigned long end_pfn = start_pfn + size; - unsigned long pfn; - - for (pfn = start_pfn; pfn < end_pfn; pfn++) { - if (!early_pfn_valid(pfn)) - continue; - page = pfn_to_page(pfn); - set_page_links(page, zone, nid, pfn); - init_page_count(page); - reset_page_mapcount(page); - SetPageReserved(page); - INIT_LIST_HEAD(&page->lru); -#ifdef WANT_PAGE_VIRTUAL - /* The shift won't overflow because ZONE_NORMAL is below 4G. */ - if (!is_highmem_idx(zone)) - set_page_address(page, __va(pfn << PAGE_SHIFT)); -#endif - } -} - -void zone_init_free_lists(struct pglist_data *pgdat, struct zone *zone, - unsigned long size) -{ - int order; - for (order = 0; order < MAX_ORDER ; order++) { - INIT_LIST_HEAD(&zone->free_area[order].free_list); - zone->free_area[order].nr_free = 0; - } -} - -#define ZONETABLE_INDEX(x, zone_nr) ((x << ZONES_SHIFT) | zone_nr) -void zonetable_add(struct zone *zone, int nid, int zid, unsigned long pfn, - unsigned long size) -{ - unsigned long snum = pfn_to_section_nr(pfn); - unsigned long end = pfn_to_section_nr(pfn + size); - - if (FLAGS_HAS_NODE) - zone_table[ZONETABLE_INDEX(nid, zid)] = zone; - else - for (; snum <= end; snum++) - zone_table[ZONETABLE_INDEX(snum, zid)] = zone; -} - -#ifndef __HAVE_ARCH_MEMMAP_INIT -#define memmap_init(size, nid, zone, start_pfn) \ - memmap_init_zone((size), (nid), (zone), (start_pfn)) -#endif - -static int __cpuinit zone_batchsize(struct zone *zone) -{ - int batch; - - /* - * The per-cpu-pages pools are set to around 1000th of the - * size of the zone. But no more than 1/2 of a meg. - * - * OK, so we don't know how big the cache is. So guess. - */ - batch = zone->present_pages / 1024; - if (batch * PAGE_SIZE > 512 * 1024) - batch = (512 * 1024) / PAGE_SIZE; - batch /= 4; /* We effectively *= 4 below */ - if (batch < 1) - batch = 1; - - /* - * Clamp the batch to a 2^n - 1 value. Having a power - * of 2 value was found to be more likely to have - * suboptimal cache aliasing properties in some cases. - * - * For example if 2 tasks are alternately allocating - * batches of pages, one task can end up with a lot - * of pages of one half of the possible page colors - * and the other with pages of the other colors. - */ - batch = (1 << (fls(batch + batch/2)-1)) - 1; - - return batch; -} - -inline void setup_pageset(struct per_cpu_pageset *p, unsigned long batch) -{ - struct per_cpu_pages *pcp; - - memset(p, 0, sizeof(*p)); - - pcp = &p->pcp[0]; /* hot */ - pcp->count = 0; - pcp->high = 6 * batch; - pcp->batch = max(1UL, 1 * batch); - INIT_LIST_HEAD(&pcp->list); - - pcp = &p->pcp[1]; /* cold*/ - pcp->count = 0; - pcp->high = 2 * batch; - pcp->batch = max(1UL, batch/2); - INIT_LIST_HEAD(&pcp->list); -} - -/* - * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist - * to the value high for the pageset p. - */ - -static void setup_pagelist_highmark(struct per_cpu_pageset *p, - unsigned long high) -{ - struct per_cpu_pages *pcp; - - pcp = &p->pcp[0]; /* hot list */ - pcp->high = high; - pcp->batch = max(1UL, high/4); - if ((high/4) > (PAGE_SHIFT * 8)) - pcp->batch = PAGE_SHIFT * 8; -} - - -#ifdef CONFIG_NUMA -/* - * Boot pageset table. One per cpu which is going to be used for all - * zones and all nodes. The parameters will be set in such a way - * that an item put on a list will immediately be handed over to - * the buddy list. This is safe since pageset manipulation is done - * with interrupts disabled. - * - * Some NUMA counter updates may also be caught by the boot pagesets. - * - * The boot_pagesets must be kept even after bootup is complete for - * unused processors and/or zones. They do play a role for bootstrapping - * hotplugged processors. - * - * zoneinfo_show() and maybe other functions do - * not check if the processor is online before following the pageset pointer. - * Other parts of the kernel may not check if the zone is available. - */ -static struct per_cpu_pageset boot_pageset[NR_CPUS]; - -/* - * Dynamically allocate memory for the - * per cpu pageset array in struct zone. - */ -static int __cpuinit process_zones(int cpu) -{ - struct zone *zone, *dzone; - - for_each_zone(zone) { - - zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset), - GFP_KERNEL, cpu_to_node(cpu)); - if (!zone_pcp(zone, cpu)) - goto bad; - - setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone)); - - if (percpu_pagelist_fraction) - setup_pagelist_highmark(zone_pcp(zone, cpu), - (zone->present_pages / percpu_pagelist_fraction)); - } - - return 0; -bad: - for_each_zone(dzone) { - if (dzone == zone) - break; - kfree(zone_pcp(dzone, cpu)); - zone_pcp(dzone, cpu) = NULL; - } - return -ENOMEM; -} - -static inline void free_zone_pagesets(int cpu) -{ - struct zone *zone; - - for_each_zone(zone) { - struct per_cpu_pageset *pset = zone_pcp(zone, cpu); - - zone_pcp(zone, cpu) = NULL; - kfree(pset); - } -} - -static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb, - unsigned long action, - void *hcpu) -{ - int cpu = (long)hcpu; - int ret = NOTIFY_OK; - - switch (action) { - case CPU_UP_PREPARE: - if (process_zones(cpu)) - ret = NOTIFY_BAD; - break; - case CPU_UP_CANCELED: - case CPU_DEAD: - free_zone_pagesets(cpu); - break; - default: - break; - } - return ret; -} - -static struct notifier_block __cpuinitdata pageset_notifier = - { &pageset_cpuup_callback, NULL, 0 }; - -void __init setup_per_cpu_pageset(void) -{ - int err; - - /* Initialize per_cpu_pageset for cpu 0. - * A cpuup callback will do this for every cpu - * as it comes online - */ - err = process_zones(smp_processor_id()); - BUG_ON(err); - register_cpu_notifier(&pageset_notifier); -} - -#endif - -static __meminit -int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages) -{ - int i; - struct pglist_data *pgdat = zone->zone_pgdat; - size_t alloc_size; - - /* - * The per-page waitqueue mechanism uses hashed waitqueues - * per zone. - */ - zone->wait_table_hash_nr_entries = - wait_table_hash_nr_entries(zone_size_pages); - zone->wait_table_bits = - wait_table_bits(zone->wait_table_hash_nr_entries); - alloc_size = zone->wait_table_hash_nr_entries - * sizeof(wait_queue_head_t); - - if (system_state == SYSTEM_BOOTING) { - zone->wait_table = (wait_queue_head_t *) - alloc_bootmem_node(pgdat, alloc_size); - } else { - /* - * This case means that a zone whose size was 0 gets new memory - * via memory hot-add. - * But it may be the case that a new node was hot-added. In - * this case vmalloc() will not be able to use this new node's - * memory - this wait_table must be initialized to use this new - * node itself as well. - * To use this new node's memory, further consideration will be - * necessary. - */ - zone->wait_table = (wait_queue_head_t *)vmalloc(alloc_size); - } - if (!zone->wait_table) - return -ENOMEM; - - for(i = 0; i < zone->wait_table_hash_nr_entries; ++i) - init_waitqueue_head(zone->wait_table + i); - - return 0; -} - -static __meminit void zone_pcp_init(struct zone *zone) -{ - int cpu; - unsigned long batch = zone_batchsize(zone); - - for (cpu = 0; cpu < NR_CPUS; cpu++) { -#ifdef CONFIG_NUMA - /* Early boot. Slab allocator not functional yet */ - zone_pcp(zone, cpu) = &boot_pageset[cpu]; - setup_pageset(&boot_pageset[cpu],0); -#else - setup_pageset(zone_pcp(zone,cpu), batch); -#endif - } - if (zone->present_pages) - printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n", - zone->name, zone->present_pages, batch); -} - -__meminit int init_currently_empty_zone(struct zone *zone, - unsigned long zone_start_pfn, - unsigned long size) -{ - struct pglist_data *pgdat = zone->zone_pgdat; - int ret; - ret = zone_wait_table_init(zone, size); - if (ret) - return ret; - pgdat->nr_zones = zone_idx(zone) + 1; - - zone->zone_start_pfn = zone_start_pfn; - - memmap_init(size, pgdat->node_id, zone_idx(zone), zone_start_pfn); - - zone_init_free_lists(pgdat, zone, zone->spanned_pages); - - return 0; -} - -/* - * Set up the zone data structures: - * - mark all pages reserved - * - mark all memory queues empty - * - clear the memory bitmaps - */ -static void __meminit free_area_init_core(struct pglist_data *pgdat, - unsigned long *zones_size, unsigned long *zholes_size) -{ - unsigned long j; - int nid = pgdat->node_id; - unsigned long zone_start_pfn = pgdat->node_start_pfn; - int ret; - - pgdat_resize_init(pgdat); - pgdat->nr_zones = 0; - init_waitqueue_head(&pgdat->kswapd_wait); - pgdat->kswapd_max_order = 0; - - for (j = 0; j < MAX_NR_ZONES; j++) { - struct zone *zone = pgdat->node_zones + j; - unsigned long size, realsize; - - realsize = size = zones_size[j]; - if (zholes_size) - realsize -= zholes_size[j]; - - if (j < ZONE_HIGHMEM) - nr_kernel_pages += realsize; - nr_all_pages += realsize; - - zone->spanned_pages = size; - zone->present_pages = realsize; -#ifdef CONFIG_NUMA - zone->min_unmapped_ratio = (realsize*sysctl_min_unmapped_ratio) - / 100; -#endif - zone->name = zone_names[j]; - spin_lock_init(&zone->lock); - spin_lock_init(&zone->lru_lock); - zone_seqlock_init(zone); - zone->zone_pgdat = pgdat; - zone->free_pages = 0; - - zone->temp_priority = zone->prev_priority = DEF_PRIORITY; - - zone_pcp_init(zone); - INIT_LIST_HEAD(&zone->active_list); - INIT_LIST_HEAD(&zone->inactive_list); - zone->nr_scan_active = 0; - zone->nr_scan_inactive = 0; - zone->nr_active = 0; - zone->nr_inactive = 0; - zap_zone_vm_stats(zone); - atomic_set(&zone->reclaim_in_progress, 0); - if (!size) - continue; - - zonetable_add(zone, nid, j, zone_start_pfn, size); - ret = init_currently_empty_zone(zone, zone_start_pfn, size); - BUG_ON(ret); - zone_start_pfn += size; - } -} - -static void __init alloc_node_mem_map(struct pglist_data *pgdat) -{ - /* Skip empty nodes */ - if (!pgdat->node_spanned_pages) - return; - -#ifdef CONFIG_FLAT_NODE_MEM_MAP - /* ia64 gets its own node_mem_map, before this, without bootmem */ - if (!pgdat->node_mem_map) { - unsigned long size, start, end; - struct page *map; - - /* - * The zone's endpoints aren't required to be MAX_ORDER - * aligned but the node_mem_map endpoints must be in order - * for the buddy allocator to function correctly. - */ - start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1); - end = pgdat->node_start_pfn + pgdat->node_spanned_pages; - end = ALIGN(end, MAX_ORDER_NR_PAGES); - size = (end - start) * sizeof(struct page); - map = alloc_remap(pgdat->node_id, size); - if (!map) - map = alloc_bootmem_node(pgdat, size); - pgdat->node_mem_map = map + (pgdat->node_start_pfn - start); - } -#ifdef CONFIG_FLATMEM - /* - * With no DISCONTIG, the global mem_map is just set as node 0's - */ - if (pgdat == NODE_DATA(0)) - mem_map = NODE_DATA(0)->node_mem_map; -#endif -#endif /* CONFIG_FLAT_NODE_MEM_MAP */ -} - -void __meminit free_area_init_node(int nid, struct pglist_data *pgdat, - unsigned long *zones_size, unsigned long node_start_pfn, - unsigned long *zholes_size) -{ - pgdat->node_id = nid; - pgdat->node_start_pfn = node_start_pfn; - calculate_zone_totalpages(pgdat, zones_size, zholes_size); - - alloc_node_mem_map(pgdat); - - free_area_init_core(pgdat, zones_size, zholes_size); -} - -#ifndef CONFIG_NEED_MULTIPLE_NODES -static bootmem_data_t contig_bootmem_data; -struct pglist_data contig_page_data = { .bdata = &contig_bootmem_data }; - -EXPORT_SYMBOL(contig_page_data); -#endif - -void __init free_area_init(unsigned long *zones_size) -{ - free_area_init_node(0, NODE_DATA(0), zones_size, - __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); -} - -#ifdef CONFIG_HOTPLUG_CPU -static int page_alloc_cpu_notify(struct notifier_block *self, - unsigned long action, void *hcpu) -{ - int cpu = (unsigned long)hcpu; - - if (action == CPU_DEAD) { - local_irq_disable(); - __drain_pages(cpu); - vm_events_fold_cpu(cpu); - local_irq_enable(); - refresh_cpu_vm_stats(cpu); - } - return NOTIFY_OK; -} -#endif /* CONFIG_HOTPLUG_CPU */ - -void __init page_alloc_init(void) -{ - hotcpu_notifier(page_alloc_cpu_notify, 0); -} - -/* - * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio - * or min_free_kbytes changes. - */ -static void calculate_totalreserve_pages(void) -{ - struct pglist_data *pgdat; - unsigned long reserve_pages = 0; - int i, j; - - for_each_online_pgdat(pgdat) { - for (i = 0; i < MAX_NR_ZONES; i++) { - struct zone *zone = pgdat->node_zones + i; - unsigned long max = 0; - - /* Find valid and maximum lowmem_reserve in the zone */ - for (j = i; j < MAX_NR_ZONES; j++) { - if (zone->lowmem_reserve[j] > max) - max = zone->lowmem_reserve[j]; - } - - /* we treat pages_high as reserved pages. */ - max += zone->pages_high; - - if (max > zone->present_pages) - max = zone->present_pages; - reserve_pages += max; - } - } - totalreserve_pages = reserve_pages; -} - -/* - * setup_per_zone_lowmem_reserve - called whenever - * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone - * has a correct pages reserved value, so an adequate number of - * pages are left in the zone after a successful __alloc_pages(). - */ -static void setup_per_zone_lowmem_reserve(void) -{ - struct pglist_data *pgdat; - int j, idx; - - for_each_online_pgdat(pgdat) { - for (j = 0; j < MAX_NR_ZONES; j++) { - struct zone *zone = pgdat->node_zones + j; - unsigned long present_pages = zone->present_pages; - - zone->lowmem_reserve[j] = 0; - - for (idx = j-1; idx >= 0; idx--) { - struct zone *lower_zone; - - if (sysctl_lowmem_reserve_ratio[idx] < 1) - sysctl_lowmem_reserve_ratio[idx] = 1; - - lower_zone = pgdat->node_zones + idx; - lower_zone->lowmem_reserve[j] = present_pages / - sysctl_lowmem_reserve_ratio[idx]; - present_pages += lower_zone->present_pages; - } - } - } - - /* update totalreserve_pages */ - calculate_totalreserve_pages(); -} - -/* - * setup_per_zone_pages_min - called when min_free_kbytes changes. Ensures - * that the pages_{min,low,high} values for each zone are set correctly - * with respect to min_free_kbytes. - */ -void setup_per_zone_pages_min(void) -{ - unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); - unsigned long lowmem_pages = 0; - struct zone *zone; - unsigned long flags; - - /* Calculate total number of !ZONE_HIGHMEM pages */ - for_each_zone(zone) { - if (!is_highmem(zone)) - lowmem_pages += zone->present_pages; - } - - for_each_zone(zone) { - u64 tmp; - - spin_lock_irqsave(&zone->lru_lock, flags); - tmp = (u64)pages_min * zone->present_pages; - do_div(tmp, lowmem_pages); - if (is_highmem(zone)) { - /* - * __GFP_HIGH and PF_MEMALLOC allocations usually don't - * need highmem pages, so cap pages_min to a small - * value here. - * - * The (pages_high-pages_low) and (pages_low-pages_min) - * deltas controls asynch page reclaim, and so should - * not be capped for highmem. - */ - int min_pages; - - min_pages = zone->present_pages / 1024; - if (min_pages < SWAP_CLUSTER_MAX) - min_pages = SWAP_CLUSTER_MAX; - if (min_pages > 128) - min_pages = 128; - zone->pages_min = min_pages; - } else { - /* - * If it's a lowmem zone, reserve a number of pages - * proportionate to the zone's size. - */ - zone->pages_min = tmp; - } - - zone->pages_low = zone->pages_min + (tmp >> 2); - zone->pages_high = zone->pages_min + (tmp >> 1); - spin_unlock_irqrestore(&zone->lru_lock, flags); - } - - /* update totalreserve_pages */ - calculate_totalreserve_pages(); -} - -/* - * Initialise min_free_kbytes. - * - * For small machines we want it small (128k min). For large machines - * we want it large (64MB max). But it is not linear, because network - * bandwidth does not increase linearly with machine size. We use - * - * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: - * min_free_kbytes = sqrt(lowmem_kbytes * 16) - * - * which yields - * - * 16MB: 512k - * 32MB: 724k - * 64MB: 1024k - * 128MB: 1448k - * 256MB: 2048k - * 512MB: 2896k - * 1024MB: 4096k - * 2048MB: 5792k - * 4096MB: 8192k - * 8192MB: 11584k - * 16384MB: 16384k - */ -static int __init init_per_zone_pages_min(void) -{ - unsigned long lowmem_kbytes; - - lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); - - min_free_kbytes = int_sqrt(lowmem_kbytes * 16); - if (min_free_kbytes < 128) - min_free_kbytes = 128; - if (min_free_kbytes > 65536) - min_free_kbytes = 65536; - setup_per_zone_pages_min(); - setup_per_zone_lowmem_reserve(); - return 0; -} -module_init(init_per_zone_pages_min) - -/* - * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so - * that we can call two helper functions whenever min_free_kbytes - * changes. - */ -int min_free_kbytes_sysctl_handler(ctl_table *table, int write, - struct file *file, void __user *buffer, size_t *length, loff_t *ppos) -{ - proc_dointvec(table, write, file, buffer, length, ppos); - setup_per_zone_pages_min(); - return 0; -} - -#ifdef CONFIG_NUMA -int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write, - struct file *file, void __user *buffer, size_t *length, loff_t *ppos) -{ - struct zone *zone; - int rc; - - rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos); - if (rc) - return rc; - - for_each_zone(zone) - zone->min_unmapped_ratio = (zone->present_pages * - sysctl_min_unmapped_ratio) / 100; - return 0; -} -#endif - -/* - * lowmem_reserve_ratio_sysctl_handler - just a wrapper around - * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() - * whenever sysctl_lowmem_reserve_ratio changes. - * - * The reserve ratio obviously has absolutely no relation with the - * pages_min watermarks. The lowmem reserve ratio can only make sense - * if in function of the boot time zone sizes. - */ -int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write, - struct file *file, void __user *buffer, size_t *length, loff_t *ppos) -{ - proc_dointvec_minmax(table, write, file, buffer, length, ppos); - setup_per_zone_lowmem_reserve(); - return 0; -} - -/* - * percpu_pagelist_fraction - changes the pcp->high for each zone on each - * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist - * can have before it gets flushed back to buddy allocator. - */ - -int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write, - struct file *file, void __user *buffer, size_t *length, loff_t *ppos) -{ - struct zone *zone; - unsigned int cpu; - int ret; - - ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos); - if (!write || (ret == -EINVAL)) - return ret; - for_each_zone(zone) { - for_each_online_cpu(cpu) { - unsigned long high; - high = zone->present_pages / percpu_pagelist_fraction; - setup_pagelist_highmark(zone_pcp(zone, cpu), high); - } - } - return 0; -} - -__initdata int hashdist = HASHDIST_DEFAULT; - -#ifdef CONFIG_NUMA -static int __init set_hashdist(char *str) -{ - if (!str) - return 0; - hashdist = simple_strtoul(str, &str, 0); - return 1; -} -__setup("hashdist=", set_hashdist); -#endif - -/* - * allocate a large system hash table from bootmem - * - it is assumed that the hash table must contain an exact power-of-2 - * quantity of entries - * - limit is the number of hash buckets, not the total allocation size - */ -void *__init alloc_large_system_hash(const char *tablename, - unsigned long bucketsize, - unsigned long numentries, - int scale, - int flags, - unsigned int *_hash_shift, - unsigned int *_hash_mask, - unsigned long limit) -{ - unsigned long long max = limit; - unsigned long log2qty, size; - void *table = NULL; - - /* allow the kernel cmdline to have a say */ - if (!numentries) { - /* round applicable memory size up to nearest megabyte */ - numentries = (flags & HASH_HIGHMEM) ? nr_all_pages : nr_kernel_pages; - numentries += (1UL << (20 - PAGE_SHIFT)) - 1; - numentries >>= 20 - PAGE_SHIFT; - numentries <<= 20 - PAGE_SHIFT; - - /* limit to 1 bucket per 2^scale bytes of low memory */ - if (scale > PAGE_SHIFT) - numentries >>= (scale - PAGE_SHIFT); - else - numentries <<= (PAGE_SHIFT - scale); - } - numentries = roundup_pow_of_two(numentries); - - /* limit allocation size to 1/16 total memory by default */ - if (max == 0) { - max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4; - do_div(max, bucketsize); - } - - if (numentries > max) - numentries = max; - - log2qty = long_log2(numentries); - - do { - size = bucketsize << log2qty; - if (flags & HASH_EARLY) - table = alloc_bootmem(size); - else if (hashdist) - table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); - else { - unsigned long order; - for (order = 0; ((1UL << order) << PAGE_SHIFT) < size; order++) - ; - table = (void*) __get_free_pages(GFP_ATOMIC, order); - } - } while (!table && size > PAGE_SIZE && --log2qty); - - if (!table) - panic("Failed to allocate %s hash table\n", tablename); - - printk("%s hash table entries: %d (order: %d, %lu bytes)\n", - tablename, - (1U << log2qty), - long_log2(size) - PAGE_SHIFT, - size); - - if (_hash_shift) - *_hash_shift = log2qty; - if (_hash_mask) - *_hash_mask = (1 << log2qty) - 1; - - return table; -} - -#ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE -struct page *pfn_to_page(unsigned long pfn) -{ - return __pfn_to_page(pfn); -} -unsigned long page_to_pfn(struct page *page) -{ - return __page_to_pfn(page); -} -EXPORT_SYMBOL(pfn_to_page); -EXPORT_SYMBOL(page_to_pfn); -#endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */ |