Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
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;
+}