| /* |
| * 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 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, |
| #ifdef CONFIG_ZONE_DMA32 |
| 256, |
| #endif |
| #ifdef CONFIG_HIGHMEM |
| 32 |
| #endif |
| }; |
| |
| 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", |
| #ifdef CONFIG_ZONE_DMA32 |
| "DMA32", |
| #endif |
| "Normal", |
| #ifdef CONFIG_HIGHMEM |
| "HighMem" |
| #endif |
| }; |
| |
| 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 ); |
| 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; |
| |
| VM_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. |
| */ |
| VM_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); |
| |
| VM_BUG_ON(page_idx & (order_size - 1)); |
| VM_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 )))) |
| 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; |
| |
| VM_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; |
| |
| arch_free_page(page, order); |
| 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; |
| VM_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 )))) |
| 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; |
| |
| arch_free_page(page, 0); |
| |
| 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; |
| |
| VM_BUG_ON(PageCompound(page)); |
| VM_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(); |
| |
| VM_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 |
| */ |
| VM_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) { |
| VM_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_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(); |
| 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 = nr_free_pages_pgdat(pgdat); |
| #ifdef CONFIG_HIGHMEM |
| val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages; |
| val->freehigh = pgdat->node_zones[ZONE_HIGHMEM].free_pages; |
| #else |
| val->totalhigh = 0; |
| val->freehigh = 0; |
| #endif |
| 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("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 >= MAX_NR_ZONES); |
| |
| do { |
| zone = pgdat->node_zones + zone_type; |
| if (populated_zone(zone)) { |
| zonelist->zones[nr_zones++] = zone; |
| check_highest_zone(zone_type); |
| } |
| zone_type--; |
| |
| } while (zone_type >= 0); |
| return nr_zones; |
| } |
| |
| #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, node, local_node; |
| enum zone_type k; |
| enum zone_type j; |
| |
| 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, enum zone_type 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); |
| |
| /* Free per_cpu_pageset if it is slab allocated */ |
| if (pset != &boot_pageset[cpu]) |
| kfree(pset); |
| zone_pcp(zone, cpu) = NULL; |
| } |
| } |
| |
| 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) |
| { |
| enum zone_type 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 (!is_highmem_idx(j)) |
| 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; |
| } |
| |
| 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 */ |