/* * 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/config.h> #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 <asm/tlbflush.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); struct pglist_data *pgdat_list __read_mostly; unsigned long totalram_pages __read_mostly; unsigned long totalhigh_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 __initdata nr_kernel_pages; unsigned long __initdata 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 ); 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); __SetPagePrivate(page); } static inline void rmv_page_order(struct page *page) { __ClearPagePrivate(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 contigious 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 free && * (c) the buddy is on the buddy system && * (d) a page and its buddy have the same order. * for recording page's order, we use page_private(page) and PG_private. * */ static inline int page_is_buddy(struct page *page, int order) { #ifdef CONFIG_HOLES_IN_ZONE if (!pfn_valid(page_to_pfn(page))) return 0; #endif if (PagePrivate(page) && (page_order(page) == order) && page_count(page) == 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_Private.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(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 )))) 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; arch_free_page(page, order); if (!PageHighMem(page)) mutex_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); __mod_page_state(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 )))) 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 */ static void zone_statistics(struct zonelist *zonelist, struct zone *z, int cpu) { #ifdef CONFIG_NUMA pg_data_t *pg = z->zone_pgdat; pg_data_t *orig = zonelist->zones[0]->zone_pgdat; struct per_cpu_pageset *p; p = zone_pcp(z, cpu); if (pg == orig) { p->numa_hit++; } else { p->numa_miss++; zone_pcp(zonelist->zones[0], cpu)->numa_foreign++; } if (pg == NODE_DATA(numa_node_id())) p->local_node++; else p->other_node++; #endif } /* * 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); __inc_page_state(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; } __mod_page_state_zone(zone, pgalloc, 1 << order); zone_statistics(zonelist, zone, cpu); 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 { if (cpuset_zone_allowed(*z, gfp_mask)) 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; 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_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 /* * Accumulate the page_state information across all CPUs. * The result is unavoidably approximate - it can change * during and after execution of this function. */ static DEFINE_PER_CPU(struct page_state, page_states) = {0}; atomic_t nr_pagecache = ATOMIC_INIT(0); EXPORT_SYMBOL(nr_pagecache); #ifdef CONFIG_SMP DEFINE_PER_CPU(long, nr_pagecache_local) = 0; #endif static void __get_page_state(struct page_state *ret, int nr, cpumask_t *cpumask) { unsigned cpu; memset(ret, 0, nr * sizeof(unsigned long)); cpus_and(*cpumask, *cpumask, cpu_online_map); for_each_cpu_mask(cpu, *cpumask) { unsigned long *in; unsigned long *out; unsigned off; unsigned next_cpu; in = (unsigned long *)&per_cpu(page_states, cpu); next_cpu = next_cpu(cpu, *cpumask); if (likely(next_cpu < NR_CPUS)) prefetch(&per_cpu(page_states, next_cpu)); out = (unsigned long *)ret; for (off = 0; off < nr; off++) *out++ += *in++; } } void get_page_state_node(struct page_state *ret, int node) { int nr; cpumask_t mask = node_to_cpumask(node); nr = offsetof(struct page_state, GET_PAGE_STATE_LAST); nr /= sizeof(unsigned long); __get_page_state(ret, nr+1, &mask); } void get_page_state(struct page_state *ret) { int nr; cpumask_t mask = CPU_MASK_ALL; nr = offsetof(struct page_state, GET_PAGE_STATE_LAST); nr /= sizeof(unsigned long); __get_page_state(ret, nr + 1, &mask); } void get_full_page_state(struct page_state *ret) { cpumask_t mask = CPU_MASK_ALL; __get_page_state(ret, sizeof(*ret) / sizeof(unsigned long), &mask); } unsigned long read_page_state_offset(unsigned long offset) { unsigned long ret = 0; int cpu; for_each_online_cpu(cpu) { unsigned long in; in = (unsigned long)&per_cpu(page_states, cpu) + offset; ret += *((unsigned long *)in); } return ret; } void __mod_page_state_offset(unsigned long offset, unsigned long delta) { void *ptr; ptr = &__get_cpu_var(page_states); *(unsigned long *)(ptr + offset) += delta; } EXPORT_SYMBOL(__mod_page_state_offset); void mod_page_state_offset(unsigned long offset, unsigned long delta) { unsigned long flags; void *ptr; local_irq_save(flags); ptr = &__get_cpu_var(page_states); *(unsigned long *)(ptr + offset) += delta; local_irq_restore(flags); } EXPORT_SYMBOL(mod_page_state_offset); void __get_zone_counts(unsigned long *active, unsigned long *inactive, unsigned long *free, struct pglist_data *pgdat) { struct zone *zones = pgdat->node_zones; int i; *active = 0; *inactive = 0; *free = 0; for (i = 0; i < MAX_NR_ZONES; i++) { *active += zones[i].nr_active; *inactive += zones[i].nr_inactive; *free += zones[i].free_pages; } } void get_zone_counts(unsigned long *active, unsigned long *inactive, unsigned long *free) { struct pglist_data *pgdat; *active = 0; *inactive = 0; *free = 0; for_each_pgdat(pgdat) { unsigned long l, m, n; __get_zone_counts(&l, &m, &n, pgdat); *active += l; *inactive += m; *free += n; } } 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) { struct page_state ps; 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_page_state(&ps); 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, ps.nr_dirty, ps.nr_writeback, ps.nr_unstable, nr_free_pages(), ps.nr_slab, ps.nr_mapped, ps.nr_page_table_pages); 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, 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 = zone->free_area[order].nr_free; total += nr << order; printk("%lu*%lukB ", nr, K(1UL) << order); } spin_unlock_irqrestore(&zone->lock, flags); 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 __init 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 __initdata 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 __init 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 __init 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 __init 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 */ void __init build_all_zonelists(void) { int i; for_each_online_node(i) build_zonelists(NODE_DATA(i)); printk("Built %i zonelists\n", num_online_nodes()); cpuset_init_current_mems_allowed(); } /* * 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 static inline unsigned long wait_table_size(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); } /* * 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 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 void zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages) { int i; struct pglist_data *pgdat = zone->zone_pgdat; /* * The per-page waitqueue mechanism uses hashed waitqueues * per zone. */ zone->wait_table_size = wait_table_size(zone_size_pages); zone->wait_table_bits = wait_table_bits(zone->wait_table_size); zone->wait_table = (wait_queue_head_t *) alloc_bootmem_node(pgdat, zone->wait_table_size * sizeof(wait_queue_head_t)); for(i = 0; i < zone->wait_table_size; ++i) init_waitqueue_head(zone->wait_table + i); } 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); } static __meminit void init_currently_empty_zone(struct zone *zone, unsigned long zone_start_pfn, unsigned long size) { struct pglist_data *pgdat = zone->zone_pgdat; zone_wait_table_init(zone, size); pgdat->nr_zones = zone_idx(zone) + 1; zone->zone_mem_map = pfn_to_page(zone_start_pfn); 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); } /* * Set up the zone data structures: * - mark all pages reserved * - mark all memory queues empty * - clear the memory bitmaps */ static void __init 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; 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; 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; atomic_set(&zone->reclaim_in_progress, 0); if (!size) continue; zonetable_add(zone, nid, j, zone_start_pfn, size); init_currently_empty_zone(zone, zone_start_pfn, size); 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; struct page *map; size = (pgdat->node_spanned_pages + 1) * sizeof(struct page); map = alloc_remap(pgdat->node_id, size); if (!map) map = alloc_bootmem_node(pgdat, size); pgdat->node_mem_map = map; } #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 __init 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_PROC_FS #include <linux/seq_file.h> static void *frag_start(struct seq_file *m, loff_t *pos) { pg_data_t *pgdat; loff_t node = *pos; for (pgdat = pgdat_list; pgdat && node; pgdat = pgdat->pgdat_next) --node; return pgdat; } static void *frag_next(struct seq_file *m, void *arg, loff_t *pos) { pg_data_t *pgdat = (pg_data_t *)arg; (*pos)++; return pgdat->pgdat_next; } static void frag_stop(struct seq_file *m, void *arg) { } /* * This walks the free areas for each zone. */ static int frag_show(struct seq_file *m, void *arg) { pg_data_t *pgdat = (pg_data_t *)arg; struct zone *zone; struct zone *node_zones = pgdat->node_zones; unsigned long flags; int order; for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) { if (!populated_zone(zone)) continue; spin_lock_irqsave(&zone->lock, flags); seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name); for (order = 0; order < MAX_ORDER; ++order) seq_printf(m, "%6lu ", zone->free_area[order].nr_free); spin_unlock_irqrestore(&zone->lock, flags); seq_putc(m, '\n'); } return 0; } struct seq_operations fragmentation_op = { .start = frag_start, .next = frag_next, .stop = frag_stop, .show = frag_show, }; /* * Output information about zones in @pgdat. */ static int zoneinfo_show(struct seq_file *m, void *arg) { pg_data_t *pgdat = arg; struct zone *zone; struct zone *node_zones = pgdat->node_zones; unsigned long flags; for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; zone++) { int i; if (!populated_zone(zone)) continue; spin_lock_irqsave(&zone->lock, flags); seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name); seq_printf(m, "\n pages free %lu" "\n min %lu" "\n low %lu" "\n high %lu" "\n active %lu" "\n inactive %lu" "\n scanned %lu (a: %lu i: %lu)" "\n spanned %lu" "\n present %lu", zone->free_pages, zone->pages_min, zone->pages_low, zone->pages_high, zone->nr_active, zone->nr_inactive, zone->pages_scanned, zone->nr_scan_active, zone->nr_scan_inactive, zone->spanned_pages, zone->present_pages); seq_printf(m, "\n protection: (%lu", zone->lowmem_reserve[0]); for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++) seq_printf(m, ", %lu", zone->lowmem_reserve[i]); seq_printf(m, ")" "\n pagesets"); for_each_online_cpu(i) { struct per_cpu_pageset *pageset; int j; pageset = zone_pcp(zone, i); for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) { if (pageset->pcp[j].count) break; } if (j == ARRAY_SIZE(pageset->pcp)) continue; for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) { seq_printf(m, "\n cpu: %i pcp: %i" "\n count: %i" "\n high: %i" "\n batch: %i", i, j, pageset->pcp[j].count, pageset->pcp[j].high, pageset->pcp[j].batch); } #ifdef CONFIG_NUMA seq_printf(m, "\n numa_hit: %lu" "\n numa_miss: %lu" "\n numa_foreign: %lu" "\n interleave_hit: %lu" "\n local_node: %lu" "\n other_node: %lu", pageset->numa_hit, pageset->numa_miss, pageset->numa_foreign, pageset->interleave_hit, pageset->local_node, pageset->other_node); #endif } seq_printf(m, "\n all_unreclaimable: %u" "\n prev_priority: %i" "\n temp_priority: %i" "\n start_pfn: %lu", zone->all_unreclaimable, zone->prev_priority, zone->temp_priority, zone->zone_start_pfn); spin_unlock_irqrestore(&zone->lock, flags); seq_putc(m, '\n'); } return 0; } struct seq_operations zoneinfo_op = { .start = frag_start, /* iterate over all zones. The same as in * fragmentation. */ .next = frag_next, .stop = frag_stop, .show = zoneinfo_show, }; static char *vmstat_text[] = { "nr_dirty", "nr_writeback", "nr_unstable", "nr_page_table_pages", "nr_mapped", "nr_slab", "pgpgin", "pgpgout", "pswpin", "pswpout", "pgalloc_high", "pgalloc_normal", "pgalloc_dma32", "pgalloc_dma", "pgfree", "pgactivate", "pgdeactivate", "pgfault", "pgmajfault", "pgrefill_high", "pgrefill_normal", "pgrefill_dma32", "pgrefill_dma", "pgsteal_high", "pgsteal_normal", "pgsteal_dma32", "pgsteal_dma", "pgscan_kswapd_high", "pgscan_kswapd_normal", "pgscan_kswapd_dma32", "pgscan_kswapd_dma", "pgscan_direct_high", "pgscan_direct_normal", "pgscan_direct_dma32", "pgscan_direct_dma", "pginodesteal", "slabs_scanned", "kswapd_steal", "kswapd_inodesteal", "pageoutrun", "allocstall", "pgrotated", "nr_bounce", }; static void *vmstat_start(struct seq_file *m, loff_t *pos) { struct page_state *ps; if (*pos >= ARRAY_SIZE(vmstat_text)) return NULL; ps = kmalloc(sizeof(*ps), GFP_KERNEL); m->private = ps; if (!ps) return ERR_PTR(-ENOMEM); get_full_page_state(ps); ps->pgpgin /= 2; /* sectors -> kbytes */ ps->pgpgout /= 2; return (unsigned long *)ps + *pos; } static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos) { (*pos)++; if (*pos >= ARRAY_SIZE(vmstat_text)) return NULL; return (unsigned long *)m->private + *pos; } static int vmstat_show(struct seq_file *m, void *arg) { unsigned long *l = arg; unsigned long off = l - (unsigned long *)m->private; seq_printf(m, "%s %lu\n", vmstat_text[off], *l); return 0; } static void vmstat_stop(struct seq_file *m, void *arg) { kfree(m->private); m->private = NULL; } struct seq_operations vmstat_op = { .start = vmstat_start, .next = vmstat_next, .stop = vmstat_stop, .show = vmstat_show, }; #endif /* CONFIG_PROC_FS */ #ifdef CONFIG_HOTPLUG_CPU static int page_alloc_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) { int cpu = (unsigned long)hcpu; long *count; unsigned long *src, *dest; if (action == CPU_DEAD) { int i; /* Drain local pagecache count. */ count = &per_cpu(nr_pagecache_local, cpu); atomic_add(*count, &nr_pagecache); *count = 0; local_irq_disable(); __drain_pages(cpu); /* Add dead cpu's page_states to our own. */ dest = (unsigned long *)&__get_cpu_var(page_states); src = (unsigned long *)&per_cpu(page_states, cpu); for (i = 0; i < sizeof(struct page_state)/sizeof(unsigned long); i++) { dest[i] += src[i]; src[i] = 0; } local_irq_enable(); } return NOTIFY_OK; } #endif /* CONFIG_HOTPLUG_CPU */ void __init page_alloc_init(void) { hotcpu_notifier(page_alloc_cpu_notify, 0); } /* * 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_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; } } } } /* * 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) { unsigned long tmp; spin_lock_irqsave(&zone->lru_lock, flags); tmp = (pages_min * zone->present_pages) / 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 / 4; zone->pages_high = zone->pages_min + tmp / 2; spin_unlock_irqrestore(&zone->lru_lock, flags); } } /* * 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; } /* * 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; }