diff options
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 2220 |
1 files changed, 2220 insertions, 0 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c new file mode 100644 index 0000000..c73dbbc --- /dev/null +++ b/mm/page_alloc.c @@ -0,0 +1,2220 @@ +/* + * 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/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/nodemask.h> +#include <linux/vmalloc.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 = { { [0] = 1UL } }; +nodemask_t node_possible_map = NODE_MASK_ALL; +struct pglist_data *pgdat_list; +unsigned long totalram_pages; +unsigned long totalhigh_pages; +long nr_swap_pages; + +/* + * 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 + */ +int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { 256, 32 }; + +EXPORT_SYMBOL(totalram_pages); +EXPORT_SYMBOL(nr_swap_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 << (ZONES_SHIFT + NODES_SHIFT)]; +EXPORT_SYMBOL(zone_table); + +static char *zone_names[MAX_NR_ZONES] = { "DMA", "Normal", "HighMem" }; +int min_free_kbytes = 1024; + +unsigned long __initdata nr_kernel_pages; +unsigned long __initdata nr_all_pages; + +/* + * Temporary debugging check for pages not lying within a given zone. + */ +static int bad_range(struct zone *zone, struct page *page) +{ + if (page_to_pfn(page) >= zone->zone_start_pfn + zone->spanned_pages) + return 1; + if (page_to_pfn(page) < zone->zone_start_pfn) + return 1; +#ifdef CONFIG_HOLES_IN_ZONE + if (!pfn_valid(page_to_pfn(page))) + return 1; +#endif + if (zone != page_zone(page)) + return 1; + return 0; +} + +static void bad_page(const char *function, struct page *page) +{ + printk(KERN_EMERG "Bad page state at %s (in process '%s', page %p)\n", + function, current->comm, page); + printk(KERN_EMERG "flags:0x%0*lx mapping:%p mapcount:%d count:%d\n", + (int)(2*sizeof(page_flags_t)), (unsigned long)page->flags, + page->mapping, page_mapcount(page), page_count(page)); + printk(KERN_EMERG "Backtrace:\n"); + dump_stack(); + printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n"); + page->flags &= ~(1 << PG_private | + 1 << PG_locked | + 1 << PG_lru | + 1 << PG_active | + 1 << PG_dirty | + 1 << PG_swapcache | + 1 << PG_writeback); + set_page_count(page, 0); + reset_page_mapcount(page); + page->mapping = NULL; + tainted |= TAINT_BAD_PAGE; +} + +#ifndef CONFIG_HUGETLB_PAGE +#define prep_compound_page(page, order) do { } while (0) +#define destroy_compound_page(page, order) do { } while (0) +#else +/* + * 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 ->mapping, if non-zero, holds the address of the + * compound page's put_page() function. + * + * The order of the allocation is stored in the first tail page's ->index + * This is only for debug at present. This usage means that zero-order pages + * may not be compound. + */ +static void prep_compound_page(struct page *page, unsigned long order) +{ + int i; + int nr_pages = 1 << order; + + page[1].mapping = NULL; + page[1].index = order; + for (i = 0; i < nr_pages; i++) { + struct page *p = page + i; + + SetPageCompound(p); + p->private = (unsigned long)page; + } +} + +static void destroy_compound_page(struct page *page, unsigned long order) +{ + int i; + int nr_pages = 1 << order; + + if (!PageCompound(page)) + return; + + if (page[1].index != order) + bad_page(__FUNCTION__, page); + + for (i = 0; i < nr_pages; i++) { + struct page *p = page + i; + + if (!PageCompound(p)) + bad_page(__FUNCTION__, page); + if (p->private != (unsigned long)page) + bad_page(__FUNCTION__, page); + ClearPageCompound(p); + } +} +#endif /* CONFIG_HUGETLB_PAGE */ + +/* + * 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; +} + +static inline void set_page_order(struct page *page, int order) { + page->private = order; + __SetPagePrivate(page); +} + +static inline void rmv_page_order(struct page *page) +{ + __ClearPagePrivate(page); + page->private = 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 free && + * (b) the buddy is on the buddy system && + * (c) a page and its buddy have the same order. + * for recording page's order, we use page->private and PG_private. + * + */ +static inline int page_is_buddy(struct page *page, int order) +{ + if (PagePrivate(page) && + (page_order(page) == order) && + !PageReserved(page) && + 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 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_pages_bulk (struct page *page, + struct zone *zone, unsigned int order) +{ + unsigned long page_idx; + int order_size = 1 << order; + + if (unlikely(order)) + 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; + + combined_idx = __find_combined_index(page_idx, order); + buddy = __page_find_buddy(page, page_idx, order); + + if (bad_range(zone, buddy)) + break; + 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); + 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 void free_pages_check(const char *function, struct page *page) +{ + if ( 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 ))) + bad_page(function, page); + if (PageDirty(page)) + ClearPageDirty(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, or 0 for all on the list. + * + * 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 int +free_pages_bulk(struct zone *zone, int count, + struct list_head *list, unsigned int order) +{ + unsigned long flags; + struct page *page = NULL; + int ret = 0; + + spin_lock_irqsave(&zone->lock, flags); + zone->all_unreclaimable = 0; + zone->pages_scanned = 0; + while (!list_empty(list) && count--) { + page = list_entry(list->prev, struct page, lru); + /* have to delete it as __free_pages_bulk list manipulates */ + list_del(&page->lru); + __free_pages_bulk(page, zone, order); + ret++; + } + spin_unlock_irqrestore(&zone->lock, flags); + return ret; +} + +void __free_pages_ok(struct page *page, unsigned int order) +{ + LIST_HEAD(list); + int i; + + arch_free_page(page, order); + + mod_page_state(pgfree, 1 << order); + +#ifndef CONFIG_MMU + if (order > 0) + for (i = 1 ; i < (1 << order) ; ++i) + __put_page(page + i); +#endif + + for (i = 0 ; i < (1 << order) ; ++i) + free_pages_check(__FUNCTION__, page + i); + list_add(&page->lru, &list); + kernel_map_pages(page, 1<<order, 0); + free_pages_bulk(page_zone(page), 1, &list, 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 struct page * +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); + } + return page; +} + +void set_page_refs(struct page *page, int order) +{ +#ifdef CONFIG_MMU + set_page_count(page, 1); +#else + int i; + + /* + * We need to reference all the pages for this order, otherwise if + * anyone accesses one of the pages with (get/put) it will be freed. + * - eg: access_process_vm() + */ + for (i = 0; i < (1 << order); i++) + set_page_count(page + i, 1); +#endif /* CONFIG_MMU */ +} + +/* + * This page is about to be returned from the page allocator + */ +static void prep_new_page(struct page *page, int order) +{ + if (page->mapping || page_mapcount(page) || + (page->flags & ( + 1 << PG_private | + 1 << PG_locked | + 1 << PG_lru | + 1 << PG_active | + 1 << PG_dirty | + 1 << PG_reclaim | + 1 << PG_swapcache | + 1 << PG_writeback ))) + bad_page(__FUNCTION__, page); + + page->flags &= ~(1 << PG_uptodate | 1 << PG_error | + 1 << PG_referenced | 1 << PG_arch_1 | + 1 << PG_checked | 1 << PG_mappedtodisk); + page->private = 0; + set_page_refs(page, order); + kernel_map_pages(page, 1 << order, 1); +} + +/* + * 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; + return expand(zone, page, order, current_order, area); + } + + 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) +{ + unsigned long flags; + int i; + int allocated = 0; + struct page *page; + + spin_lock_irqsave(&zone->lock, flags); + for (i = 0; i < count; ++i) { + page = __rmqueue(zone, order); + if (page == NULL) + break; + allocated++; + list_add_tail(&page->lru, list); + } + spin_unlock_irqrestore(&zone->lock, flags); + return allocated; +} + +#if defined(CONFIG_PM) || defined(CONFIG_HOTPLUG_CPU) +static void __drain_pages(unsigned int cpu) +{ + struct zone *zone; + int i; + + for_each_zone(zone) { + struct per_cpu_pageset *pset; + + pset = &zone->pageset[cpu]; + for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) { + struct per_cpu_pages *pcp; + + pcp = &pset->pcp[i]; + pcp->count -= free_pages_bulk(zone, pcp->count, + &pcp->list, 0); + } + } +} +#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) +{ +#ifdef CONFIG_NUMA + unsigned long flags; + int cpu; + pg_data_t *pg = z->zone_pgdat; + pg_data_t *orig = zonelist->zones[0]->zone_pgdat; + struct per_cpu_pageset *p; + + local_irq_save(flags); + cpu = smp_processor_id(); + p = &z->pageset[cpu]; + if (pg == orig) { + z->pageset[cpu].numa_hit++; + } else { + p->numa_miss++; + zonelist->zones[0]->pageset[cpu].numa_foreign++; + } + if (pg == NODE_DATA(numa_node_id())) + p->local_node++; + else + p->other_node++; + local_irq_restore(flags); +#endif +} + +/* + * Free a 0-order page + */ +static void FASTCALL(free_hot_cold_page(struct page *page, int cold)); +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); + + kernel_map_pages(page, 1, 0); + inc_page_state(pgfree); + if (PageAnon(page)) + page->mapping = NULL; + free_pages_check(__FUNCTION__, page); + pcp = &zone->pageset[get_cpu()].pcp[cold]; + local_irq_save(flags); + if (pcp->count >= pcp->high) + pcp->count -= free_pages_bulk(zone, pcp->batch, &pcp->list, 0); + list_add(&page->lru, &pcp->list); + pcp->count++; + 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); +} + +static inline void prep_zero_page(struct page *page, int order, unsigned int __nocast gfp_flags) +{ + int i; + + BUG_ON((gfp_flags & (__GFP_WAIT | __GFP_HIGHMEM)) == __GFP_HIGHMEM); + for(i = 0; i < (1 << order); i++) + clear_highpage(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 zone *zone, int order, unsigned int __nocast gfp_flags) +{ + unsigned long flags; + struct page *page = NULL; + int cold = !!(gfp_flags & __GFP_COLD); + + if (order == 0) { + struct per_cpu_pages *pcp; + + pcp = &zone->pageset[get_cpu()].pcp[cold]; + local_irq_save(flags); + if (pcp->count <= pcp->low) + pcp->count += rmqueue_bulk(zone, 0, + pcp->batch, &pcp->list); + if (pcp->count) { + page = list_entry(pcp->list.next, struct page, lru); + list_del(&page->lru); + pcp->count--; + } + local_irq_restore(flags); + put_cpu(); + } + + if (page == NULL) { + spin_lock_irqsave(&zone->lock, flags); + page = __rmqueue(zone, order); + spin_unlock_irqrestore(&zone->lock, flags); + } + + if (page != NULL) { + BUG_ON(bad_range(zone, page)); + mod_page_state_zone(zone, pgalloc, 1 << order); + prep_new_page(page, order); + + if (gfp_flags & __GFP_ZERO) + prep_zero_page(page, order, gfp_flags); + + if (order && (gfp_flags & __GFP_COMP)) + prep_compound_page(page, order); + } + return page; +} + +/* + * 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 can_try_harder, int gfp_high) +{ + /* free_pages my go negative - that's OK */ + long min = mark, free_pages = z->free_pages - (1 << order) + 1; + int o; + + if (gfp_high) + min -= min / 2; + if (can_try_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; +} + +/* + * This is the 'heart' of the zoned buddy allocator. + */ +struct page * fastcall +__alloc_pages(unsigned int __nocast gfp_mask, unsigned int order, + struct zonelist *zonelist) +{ + const int wait = gfp_mask & __GFP_WAIT; + struct zone **zones, *z; + struct page *page; + struct reclaim_state reclaim_state; + struct task_struct *p = current; + int i; + int classzone_idx; + int do_retry; + int can_try_harder; + int did_some_progress; + + might_sleep_if(wait); + + /* + * The caller may dip into page reserves a bit more if the caller + * cannot run direct reclaim, or is the caller has realtime scheduling + * policy + */ + can_try_harder = (unlikely(rt_task(p)) && !in_interrupt()) || !wait; + + zones = zonelist->zones; /* the list of zones suitable for gfp_mask */ + + if (unlikely(zones[0] == NULL)) { + /* Should this ever happen?? */ + return NULL; + } + + classzone_idx = zone_idx(zones[0]); + + restart: + /* Go through the zonelist once, looking for a zone with enough free */ + for (i = 0; (z = zones[i]) != NULL; i++) { + + if (!zone_watermark_ok(z, order, z->pages_low, + classzone_idx, 0, 0)) + continue; + + if (!cpuset_zone_allowed(z)) + continue; + + page = buffered_rmqueue(z, order, gfp_mask); + if (page) + goto got_pg; + } + + for (i = 0; (z = zones[i]) != NULL; i++) + wakeup_kswapd(z, order); + + /* + * Go through the zonelist again. Let __GFP_HIGH and allocations + * coming from realtime tasks to 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. + */ + for (i = 0; (z = zones[i]) != NULL; i++) { + if (!zone_watermark_ok(z, order, z->pages_min, + classzone_idx, can_try_harder, + gfp_mask & __GFP_HIGH)) + continue; + + if (wait && !cpuset_zone_allowed(z)) + continue; + + page = buffered_rmqueue(z, order, gfp_mask); + 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()) { + /* go through the zonelist yet again, ignoring mins */ + for (i = 0; (z = zones[i]) != NULL; i++) { + if (!cpuset_zone_allowed(z)) + continue; + page = buffered_rmqueue(z, order, gfp_mask); + if (page) + goto got_pg; + } + goto nopage; + } + + /* Atomic allocations - we can't balance anything */ + if (!wait) + goto nopage; + +rebalance: + cond_resched(); + + /* We now go into synchronous reclaim */ + p->flags |= PF_MEMALLOC; + reclaim_state.reclaimed_slab = 0; + p->reclaim_state = &reclaim_state; + + did_some_progress = try_to_free_pages(zones, gfp_mask, order); + + p->reclaim_state = NULL; + p->flags &= ~PF_MEMALLOC; + + cond_resched(); + + if (likely(did_some_progress)) { + /* + * 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. + */ + for (i = 0; (z = zones[i]) != NULL; i++) { + if (!zone_watermark_ok(z, order, z->pages_min, + classzone_idx, can_try_harder, + gfp_mask & __GFP_HIGH)) + continue; + + if (!cpuset_zone_allowed(z)) + continue; + + page = buffered_rmqueue(z, order, gfp_mask); + 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. + */ + for (i = 0; (z = zones[i]) != NULL; i++) { + if (!zone_watermark_ok(z, order, z->pages_high, + classzone_idx, 0, 0)) + continue; + + if (!cpuset_zone_allowed(z)) + continue; + + page = buffered_rmqueue(z, order, gfp_mask); + if (page) + goto got_pg; + } + + out_of_memory(gfp_mask); + 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(); + } + return NULL; +got_pg: + zone_statistics(zonelist, z); + return page; +} + +EXPORT_SYMBOL(__alloc_pages); + +/* + * Common helper functions. + */ +fastcall unsigned long __get_free_pages(unsigned int __nocast 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(unsigned int __nocast 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); + + 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 (!PageReserved(page) && 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) +{ + pg_data_t *pgdat; + unsigned int sum = 0; + + for_each_pgdat(pgdat) { + 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_USER & GFP_ZONEMASK); +} + +/* + * Amount of free RAM allocatable within all zones + */ +unsigned int nr_free_pagecache_pages(void) +{ + return nr_free_zone_pages(GFP_HIGHUSER & GFP_ZONEMASK); +} + +#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 + +void __get_page_state(struct page_state *ret, int nr) +{ + int cpu = 0; + + memset(ret, 0, sizeof(*ret)); + + cpu = first_cpu(cpu_online_map); + while (cpu < NR_CPUS) { + unsigned long *in, *out, off; + + in = (unsigned long *)&per_cpu(page_states, cpu); + + cpu = next_cpu(cpu, cpu_online_map); + + if (cpu < NR_CPUS) + prefetch(&per_cpu(page_states, cpu)); + + out = (unsigned long *)ret; + for (off = 0; off < nr; off++) + *out++ += *in++; + } +} + +void get_page_state(struct page_state *ret) +{ + int nr; + + nr = offsetof(struct page_state, GET_PAGE_STATE_LAST); + nr /= sizeof(unsigned long); + + __get_page_state(ret, nr + 1); +} + +void get_full_page_state(struct page_state *ret) +{ + __get_page_state(ret, sizeof(*ret) / sizeof(unsigned long)); +} + +unsigned long __read_page_state(unsigned 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(unsigned 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); + +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 (!zone->present_pages) { + printk(" empty\n"); + continue; + } else + printk("\n"); + + for (cpu = 0; cpu < NR_CPUS; ++cpu) { + struct per_cpu_pageset *pageset; + + if (!cpu_possible(cpu)) + continue; + + pageset = zone->pageset + cpu; + + for (temperature = 0; temperature < 2; temperature++) + printk("cpu %d %s: low %d, high %d, batch %d\n", + cpu, + temperature ? "cold" : "hot", + pageset->pcp[temperature].low, + pageset->pcp[temperature].high, + pageset->pcp[temperature].batch); + } + } + + get_page_state(&ps); + get_zone_counts(&active, &inactive, &free); + + printk("\nFree 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 (!zone->present_pages) { + 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. + */ +static int __init build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist, int j, int k) +{ + switch (k) { + struct zone *zone; + default: + BUG(); + case ZONE_HIGHMEM: + zone = pgdat->node_zones + ZONE_HIGHMEM; + if (zone->present_pages) { +#ifndef CONFIG_HIGHMEM + BUG(); +#endif + zonelist->zones[j++] = zone; + } + case ZONE_NORMAL: + zone = pgdat->node_zones + ZONE_NORMAL; + if (zone->present_pages) + zonelist->zones[j++] = zone; + case ZONE_DMA: + zone = pgdat->node_zones + ZONE_DMA; + if (zone->present_pages) + zonelist->zones[j++] = zone; + } + + return j; +} + +#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 i, n, val; + int min_val = INT_MAX; + int best_node = -1; + + for_each_online_node(i) { + cpumask_t tmp; + + /* Start from local node */ + n = (node+i) % num_online_nodes(); + + /* Don't want a node to appear more than once */ + if (node_isset(n, *used_node_mask)) + continue; + + /* Use the local node if we haven't already */ + if (!node_isset(node, *used_node_mask)) { + best_node = node; + break; + } + + /* Use the distance array to find the distance */ + val = node_distance(node, n); + + /* 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) { + /* + * We don't want to pressure a particular node. + * So adding penalty to the first node in same + * distance group to make it round-robin. + */ + if (node_distance(local_node, node) != + node_distance(local_node, prev_node)) + node_load[node] += load; + prev_node = node; + load--; + for (i = 0; i < GFP_ZONETYPES; i++) { + zonelist = pgdat->node_zonelists + i; + for (j = 0; zonelist->zones[j] != NULL; j++); + + k = ZONE_NORMAL; + if (i & __GFP_HIGHMEM) + k = ZONE_HIGHMEM; + if (i & __GFP_DMA) + k = ZONE_DMA; + + 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 = ZONE_NORMAL; + if (i & __GFP_HIGHMEM) + k = ZONE_HIGHMEM; + if (i & __GFP_DMA) + k = ZONE_DMA; + + 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 __init memmap_init_zone(unsigned long size, int nid, unsigned long zone, + unsigned long start_pfn) +{ + struct page *start = pfn_to_page(start_pfn); + struct page *page; + + for (page = start; page < (start + size); page++) { + set_page_zone(page, NODEZONE(nid, zone)); + set_page_count(page, 0); + 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(start_pfn << PAGE_SHIFT)); +#endif + start_pfn++; + } +} + +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; + } +} + +#ifndef __HAVE_ARCH_MEMMAP_INIT +#define memmap_init(size, nid, zone, start_pfn) \ + memmap_init_zone((size), (nid), (zone), (start_pfn)) +#endif + +/* + * 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 i, j; + const unsigned long zone_required_alignment = 1UL << (MAX_ORDER-1); + int cpu, nid = pgdat->node_id; + unsigned long zone_start_pfn = pgdat->node_start_pfn; + + 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; + unsigned long batch; + + zone_table[NODEZONE(nid, j)] = zone; + realsize = size = zones_size[j]; + if (zholes_size) + realsize -= zholes_size[j]; + + if (j == ZONE_DMA || j == ZONE_NORMAL) + 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->zone_pgdat = pgdat; + zone->free_pages = 0; + + zone->temp_priority = zone->prev_priority = DEF_PRIORITY; + + /* + * The per-cpu-pages pools are set to around 1000th of the + * size of the zone. But no more than 1/4 of a meg - there's + * no point in going beyond the size of L2 cache. + * + * OK, so we don't know how big the cache is. So guess. + */ + batch = zone->present_pages / 1024; + if (batch * PAGE_SIZE > 256 * 1024) + batch = (256 * 1024) / PAGE_SIZE; + batch /= 4; /* We effectively *= 4 below */ + if (batch < 1) + batch = 1; + + for (cpu = 0; cpu < NR_CPUS; cpu++) { + struct per_cpu_pages *pcp; + + pcp = &zone->pageset[cpu].pcp[0]; /* hot */ + pcp->count = 0; + pcp->low = 2 * batch; + pcp->high = 6 * batch; + pcp->batch = 1 * batch; + INIT_LIST_HEAD(&pcp->list); + + pcp = &zone->pageset[cpu].pcp[1]; /* cold */ + pcp->count = 0; + pcp->low = 0; + pcp->high = 2 * batch; + pcp->batch = 1 * batch; + INIT_LIST_HEAD(&pcp->list); + } + printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n", + zone_names[j], realsize, batch); + 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; + if (!size) + continue; + + /* + * The per-page waitqueue mechanism uses hashed waitqueues + * per zone. + */ + zone->wait_table_size = wait_table_size(size); + 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); + + pgdat->nr_zones = j+1; + + zone->zone_mem_map = pfn_to_page(zone_start_pfn); + zone->zone_start_pfn = zone_start_pfn; + + if ((zone_start_pfn) & (zone_required_alignment-1)) + printk(KERN_CRIT "BUG: wrong zone alignment, it will crash\n"); + + memmap_init(size, nid, j, zone_start_pfn); + + zone_start_pfn += size; + + zone_init_free_lists(pgdat, zone, zone->spanned_pages); + } +} + +static void __init alloc_node_mem_map(struct pglist_data *pgdat) +{ + unsigned long size; + + /* Skip empty nodes */ + if (!pgdat->node_spanned_pages) + return; + + /* ia64 gets its own node_mem_map, before this, without bootmem */ + if (!pgdat->node_mem_map) { + size = (pgdat->node_spanned_pages + 1) * sizeof(struct page); + pgdat->node_mem_map = alloc_bootmem_node(pgdat, size); + } +#ifndef CONFIG_DISCONTIGMEM + /* + * 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 +} + +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_DISCONTIGMEM +static bootmem_data_t contig_bootmem_data; +struct pglist_data contig_page_data = { .bdata = &contig_bootmem_data }; + +EXPORT_SYMBOL(contig_page_data); + +void __init free_area_init(unsigned long *zones_size) +{ + free_area_init_node(0, &contig_page_data, zones_size, + __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); +} +#endif + +#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 (!zone->present_pages) + 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, +}; + +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_dma", + "pgfree", + "pgactivate", + "pgdeactivate", + + "pgfault", + "pgmajfault", + "pgrefill_high", + "pgrefill_normal", + "pgrefill_dma", + + "pgsteal_high", + "pgsteal_normal", + "pgsteal_dma", + "pgscan_kswapd_high", + "pgscan_kswapd_normal", + + "pgscan_kswapd_dma", + "pgscan_direct_high", + "pgscan_direct_normal", + "pgscan_direct_dma", + "pginodesteal", + + "slabs_scanned", + "kswapd_steal", + "kswapd_inodesteal", + "pageoutrun", + "allocstall", + + "pgrotated", +}; + +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. + */ +static 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) { + spin_lock_irqsave(&zone->lru_lock, flags); + if (is_highmem(zone)) { + /* + * Often, highmem doesn't need to reserve any pages. + * But the pages_min/low/high values are also used for + * batching up page reclaim activity so we need a + * decent value here. + */ + 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 = (pages_min * zone->present_pages) / + lowmem_pages; + } + + /* + * When interpreting these watermarks, just keep in mind that: + * zone->pages_min == (zone->pages_min * 4) / 4; + */ + zone->pages_low = (zone->pages_min * 5) / 4; + zone->pages_high = (zone->pages_min * 6) / 4; + 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; +} + +__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); + } + /* rounded up to nearest power of 2 in size */ + numentries = 1UL << (long_log2(numentries) + 1); + + /* 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; +} |
