mm: page_alloc: remove trailing whitespace
[linux-2.6.git] / mm / swap.c
index 21d15f9..5c13f13 100644 (file)
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -5,7 +5,7 @@
  */
 
 /*
- * This file contains the default values for the opereation of the
+ * This file contains the default values for the operation of the
  * Linux VM subsystem. Fine-tuning documentation can be found in
  * Documentation/sysctl/vm.txt.
  * Started 18.12.91
 #include <linux/pagemap.h>
 #include <linux/pagevec.h>
 #include <linux/init.h>
-#include <linux/module.h>
+#include <linux/export.h>
 #include <linux/mm_inline.h>
-#include <linux/buffer_head.h> /* for try_to_release_page() */
-#include <linux/module.h>
 #include <linux/percpu_counter.h>
 #include <linux/percpu.h>
 #include <linux/cpu.h>
 #include <linux/notifier.h>
-#include <linux/init.h>
+#include <linux/backing-dev.h>
+#include <linux/memcontrol.h>
+#include <linux/gfp.h>
+
+#include "internal.h"
 
 /* How many pages do we try to swap or page in/out together? */
 int page_cluster;
 
-#ifdef CONFIG_HUGETLB_PAGE
+static DEFINE_PER_CPU(struct pagevec[NR_LRU_LISTS], lru_add_pvecs);
+static DEFINE_PER_CPU(struct pagevec, lru_rotate_pvecs);
+static DEFINE_PER_CPU(struct pagevec, lru_deactivate_pvecs);
 
-void put_page(struct page *page)
+/*
+ * This path almost never happens for VM activity - pages are normally
+ * freed via pagevecs.  But it gets used by networking.
+ */
+static void __page_cache_release(struct page *page)
+{
+       if (PageLRU(page)) {
+               unsigned long flags;
+               struct zone *zone = page_zone(page);
+
+               spin_lock_irqsave(&zone->lru_lock, flags);
+               VM_BUG_ON(!PageLRU(page));
+               __ClearPageLRU(page);
+               del_page_from_lru_list(zone, page, page_off_lru(page));
+               spin_unlock_irqrestore(&zone->lru_lock, flags);
+       }
+}
+
+static void __put_single_page(struct page *page)
+{
+       __page_cache_release(page);
+       free_hot_cold_page(page, 0);
+}
+
+static void __put_compound_page(struct page *page)
 {
-       if (unlikely(PageCompound(page))) {
-               page = (struct page *)page->private;
-               if (put_page_testzero(page)) {
-                       void (*dtor)(struct page *page);
+       compound_page_dtor *dtor;
 
-                       dtor = (void (*)(struct page *))page[1].mapping;
-                       (*dtor)(page);
+       __page_cache_release(page);
+       dtor = get_compound_page_dtor(page);
+       (*dtor)(page);
+}
+
+static void put_compound_page(struct page *page)
+{
+       if (unlikely(PageTail(page))) {
+               /* __split_huge_page_refcount can run under us */
+               struct page *page_head = compound_trans_head(page);
+
+               if (likely(page != page_head &&
+                          get_page_unless_zero(page_head))) {
+                       unsigned long flags;
+                       /*
+                        * page_head wasn't a dangling pointer but it
+                        * may not be a head page anymore by the time
+                        * we obtain the lock. That is ok as long as it
+                        * can't be freed from under us.
+                        */
+                       flags = compound_lock_irqsave(page_head);
+                       if (unlikely(!PageTail(page))) {
+                               /* __split_huge_page_refcount run before us */
+                               compound_unlock_irqrestore(page_head, flags);
+                               VM_BUG_ON(PageHead(page_head));
+                               if (put_page_testzero(page_head))
+                                       __put_single_page(page_head);
+                       out_put_single:
+                               if (put_page_testzero(page))
+                                       __put_single_page(page);
+                               return;
+                       }
+                       VM_BUG_ON(page_head != page->first_page);
+                       /*
+                        * We can release the refcount taken by
+                        * get_page_unless_zero() now that
+                        * __split_huge_page_refcount() is blocked on
+                        * the compound_lock.
+                        */
+                       if (put_page_testzero(page_head))
+                               VM_BUG_ON(1);
+                       /* __split_huge_page_refcount will wait now */
+                       VM_BUG_ON(page_mapcount(page) <= 0);
+                       atomic_dec(&page->_mapcount);
+                       VM_BUG_ON(atomic_read(&page_head->_count) <= 0);
+                       VM_BUG_ON(atomic_read(&page->_count) != 0);
+                       compound_unlock_irqrestore(page_head, flags);
+                       if (put_page_testzero(page_head)) {
+                               if (PageHead(page_head))
+                                       __put_compound_page(page_head);
+                               else
+                                       __put_single_page(page_head);
+                       }
+               } else {
+                       /* page_head is a dangling pointer */
+                       VM_BUG_ON(PageTail(page));
+                       goto out_put_single;
                }
-               return;
+       } else if (put_page_testzero(page)) {
+               if (PageHead(page))
+                       __put_compound_page(page);
+               else
+                       __put_single_page(page);
        }
-       if (put_page_testzero(page))
-               __page_cache_release(page);
+}
+
+void put_page(struct page *page)
+{
+       if (unlikely(PageCompound(page)))
+               put_compound_page(page);
+       else if (put_page_testzero(page))
+               __put_single_page(page);
 }
 EXPORT_SYMBOL(put_page);
-#endif
 
 /*
- * Writeback is about to end against a page which has been marked for immediate
- * reclaim.  If it still appears to be reclaimable, move it to the tail of the
- * inactive list.  The page still has PageWriteback set, which will pin it.
- *
- * We don't expect many pages to come through here, so don't bother batching
- * things up.
- *
- * To avoid placing the page at the tail of the LRU while PG_writeback is still
- * set, this function will clear PG_writeback before performing the page
- * motion.  Do that inside the lru lock because once PG_writeback is cleared
- * we may not touch the page.
- *
- * Returns zero if it cleared PG_writeback.
+ * This function is exported but must not be called by anything other
+ * than get_page(). It implements the slow path of get_page().
  */
-int rotate_reclaimable_page(struct page *page)
+bool __get_page_tail(struct page *page)
 {
-       struct zone *zone;
+       /*
+        * This takes care of get_page() if run on a tail page
+        * returned by one of the get_user_pages/follow_page variants.
+        * get_user_pages/follow_page itself doesn't need the compound
+        * lock because it runs __get_page_tail_foll() under the
+        * proper PT lock that already serializes against
+        * split_huge_page().
+        */
        unsigned long flags;
+       bool got = false;
+       struct page *page_head = compound_trans_head(page);
+
+       if (likely(page != page_head && get_page_unless_zero(page_head))) {
+               /*
+                * page_head wasn't a dangling pointer but it
+                * may not be a head page anymore by the time
+                * we obtain the lock. That is ok as long as it
+                * can't be freed from under us.
+                */
+               flags = compound_lock_irqsave(page_head);
+               /* here __split_huge_page_refcount won't run anymore */
+               if (likely(PageTail(page))) {
+                       __get_page_tail_foll(page, false);
+                       got = true;
+               }
+               compound_unlock_irqrestore(page_head, flags);
+               if (unlikely(!got))
+                       put_page(page_head);
+       }
+       return got;
+}
+EXPORT_SYMBOL(__get_page_tail);
 
-       if (PageLocked(page))
-               return 1;
-       if (PageDirty(page))
-               return 1;
-       if (PageActive(page))
-               return 1;
-       if (!PageLRU(page))
-               return 1;
-
-       zone = page_zone(page);
-       spin_lock_irqsave(&zone->lru_lock, flags);
-       if (PageLRU(page) && !PageActive(page)) {
-               list_del(&page->lru);
-               list_add_tail(&page->lru, &zone->inactive_list);
-               inc_page_state(pgrotated);
+/**
+ * put_pages_list() - release a list of pages
+ * @pages: list of pages threaded on page->lru
+ *
+ * Release a list of pages which are strung together on page.lru.  Currently
+ * used by read_cache_pages() and related error recovery code.
+ */
+void put_pages_list(struct list_head *pages)
+{
+       while (!list_empty(pages)) {
+               struct page *victim;
+
+               victim = list_entry(pages->prev, struct page, lru);
+               list_del(&victim->lru);
+               page_cache_release(victim);
        }
-       if (!test_clear_page_writeback(page))
-               BUG();
-       spin_unlock_irqrestore(&zone->lru_lock, flags);
-       return 0;
+}
+EXPORT_SYMBOL(put_pages_list);
+
+static void pagevec_lru_move_fn(struct pagevec *pvec,
+                               void (*move_fn)(struct page *page, void *arg),
+                               void *arg)
+{
+       int i;
+       struct zone *zone = NULL;
+       unsigned long flags = 0;
+
+       for (i = 0; i < pagevec_count(pvec); i++) {
+               struct page *page = pvec->pages[i];
+               struct zone *pagezone = page_zone(page);
+
+               if (pagezone != zone) {
+                       if (zone)
+                               spin_unlock_irqrestore(&zone->lru_lock, flags);
+                       zone = pagezone;
+                       spin_lock_irqsave(&zone->lru_lock, flags);
+               }
+
+               (*move_fn)(page, arg);
+       }
+       if (zone)
+               spin_unlock_irqrestore(&zone->lru_lock, flags);
+       release_pages(pvec->pages, pvec->nr, pvec->cold);
+       pagevec_reinit(pvec);
+}
+
+static void pagevec_move_tail_fn(struct page *page, void *arg)
+{
+       int *pgmoved = arg;
+
+       if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
+               enum lru_list lru = page_lru_base_type(page);
+               struct lruvec *lruvec;
+
+               lruvec = mem_cgroup_lru_move_lists(page_zone(page),
+                                                  page, lru, lru);
+               list_move_tail(&page->lru, &lruvec->lists[lru]);
+               (*pgmoved)++;
+       }
+}
+
+/*
+ * pagevec_move_tail() must be called with IRQ disabled.
+ * Otherwise this may cause nasty races.
+ */
+static void pagevec_move_tail(struct pagevec *pvec)
+{
+       int pgmoved = 0;
+
+       pagevec_lru_move_fn(pvec, pagevec_move_tail_fn, &pgmoved);
+       __count_vm_events(PGROTATED, pgmoved);
 }
 
 /*
- * FIXME: speed this up?
+ * Writeback is about to end against a page which has been marked for immediate
+ * reclaim.  If it still appears to be reclaimable, move it to the tail of the
+ * inactive list.
  */
-void fastcall activate_page(struct page *page)
+void rotate_reclaimable_page(struct page *page)
+{
+       if (!PageLocked(page) && !PageDirty(page) && !PageActive(page) &&
+           !PageUnevictable(page) && PageLRU(page)) {
+               struct pagevec *pvec;
+               unsigned long flags;
+
+               page_cache_get(page);
+               local_irq_save(flags);
+               pvec = &__get_cpu_var(lru_rotate_pvecs);
+               if (!pagevec_add(pvec, page))
+                       pagevec_move_tail(pvec);
+               local_irq_restore(flags);
+       }
+}
+
+static void update_page_reclaim_stat(struct zone *zone, struct page *page,
+                                    int file, int rotated)
+{
+       struct zone_reclaim_stat *reclaim_stat = &zone->reclaim_stat;
+       struct zone_reclaim_stat *memcg_reclaim_stat;
+
+       memcg_reclaim_stat = mem_cgroup_get_reclaim_stat_from_page(page);
+
+       reclaim_stat->recent_scanned[file]++;
+       if (rotated)
+               reclaim_stat->recent_rotated[file]++;
+
+       if (!memcg_reclaim_stat)
+               return;
+
+       memcg_reclaim_stat->recent_scanned[file]++;
+       if (rotated)
+               memcg_reclaim_stat->recent_rotated[file]++;
+}
+
+static void __activate_page(struct page *page, void *arg)
 {
        struct zone *zone = page_zone(page);
 
-       spin_lock_irq(&zone->lru_lock);
-       if (PageLRU(page) && !PageActive(page)) {
-               del_page_from_inactive_list(zone, page);
+       if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
+               int file = page_is_file_cache(page);
+               int lru = page_lru_base_type(page);
+               del_page_from_lru_list(zone, page, lru);
+
                SetPageActive(page);
-               add_page_to_active_list(zone, page);
-               inc_page_state(pgactivate);
+               lru += LRU_ACTIVE;
+               add_page_to_lru_list(zone, page, lru);
+               __count_vm_event(PGACTIVATE);
+
+               update_page_reclaim_stat(zone, page, file, 1);
        }
+}
+
+#ifdef CONFIG_SMP
+static DEFINE_PER_CPU(struct pagevec, activate_page_pvecs);
+
+static void activate_page_drain(int cpu)
+{
+       struct pagevec *pvec = &per_cpu(activate_page_pvecs, cpu);
+
+       if (pagevec_count(pvec))
+               pagevec_lru_move_fn(pvec, __activate_page, NULL);
+}
+
+void activate_page(struct page *page)
+{
+       if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
+               struct pagevec *pvec = &get_cpu_var(activate_page_pvecs);
+
+               page_cache_get(page);
+               if (!pagevec_add(pvec, page))
+                       pagevec_lru_move_fn(pvec, __activate_page, NULL);
+               put_cpu_var(activate_page_pvecs);
+       }
+}
+
+#else
+static inline void activate_page_drain(int cpu)
+{
+}
+
+void activate_page(struct page *page)
+{
+       struct zone *zone = page_zone(page);
+
+       spin_lock_irq(&zone->lru_lock);
+       __activate_page(page, NULL);
        spin_unlock_irq(&zone->lru_lock);
 }
+#endif
 
 /*
  * Mark a page as having seen activity.
@@ -120,77 +359,216 @@ void fastcall activate_page(struct page *page)
  * inactive,referenced         ->      active,unreferenced
  * active,unreferenced         ->      active,referenced
  */
-void fastcall mark_page_accessed(struct page *page)
+void mark_page_accessed(struct page *page)
 {
-       if (!PageActive(page) && PageReferenced(page) && PageLRU(page)) {
+       if (!PageActive(page) && !PageUnevictable(page) &&
+                       PageReferenced(page) && PageLRU(page)) {
                activate_page(page);
                ClearPageReferenced(page);
        } else if (!PageReferenced(page)) {
                SetPageReferenced(page);
        }
 }
-
 EXPORT_SYMBOL(mark_page_accessed);
 
-/**
- * lru_cache_add: add a page to the page lists
- * @page: the page to add
- */
-static DEFINE_PER_CPU(struct pagevec, lru_add_pvecs) = { 0, };
-static DEFINE_PER_CPU(struct pagevec, lru_add_active_pvecs) = { 0, };
-
-void fastcall lru_cache_add(struct page *page)
+void __lru_cache_add(struct page *page, enum lru_list lru)
 {
-       struct pagevec *pvec = &get_cpu_var(lru_add_pvecs);
+       struct pagevec *pvec = &get_cpu_var(lru_add_pvecs)[lru];
 
        page_cache_get(page);
        if (!pagevec_add(pvec, page))
-               __pagevec_lru_add(pvec);
+               __pagevec_lru_add(pvec, lru);
        put_cpu_var(lru_add_pvecs);
 }
+EXPORT_SYMBOL(__lru_cache_add);
 
-void fastcall lru_cache_add_active(struct page *page)
+/**
+ * lru_cache_add_lru - add a page to a page list
+ * @page: the page to be added to the LRU.
+ * @lru: the LRU list to which the page is added.
+ */
+void lru_cache_add_lru(struct page *page, enum lru_list lru)
 {
-       struct pagevec *pvec = &get_cpu_var(lru_add_active_pvecs);
+       if (PageActive(page)) {
+               VM_BUG_ON(PageUnevictable(page));
+               ClearPageActive(page);
+       } else if (PageUnevictable(page)) {
+               VM_BUG_ON(PageActive(page));
+               ClearPageUnevictable(page);
+       }
 
-       page_cache_get(page);
-       if (!pagevec_add(pvec, page))
-               __pagevec_lru_add_active(pvec);
-       put_cpu_var(lru_add_active_pvecs);
+       VM_BUG_ON(PageLRU(page) || PageActive(page) || PageUnevictable(page));
+       __lru_cache_add(page, lru);
 }
 
-void lru_add_drain(void)
+/**
+ * add_page_to_unevictable_list - add a page to the unevictable list
+ * @page:  the page to be added to the unevictable list
+ *
+ * Add page directly to its zone's unevictable list.  To avoid races with
+ * tasks that might be making the page evictable, through eg. munlock,
+ * munmap or exit, while it's not on the lru, we want to add the page
+ * while it's locked or otherwise "invisible" to other tasks.  This is
+ * difficult to do when using the pagevec cache, so bypass that.
+ */
+void add_page_to_unevictable_list(struct page *page)
 {
-       struct pagevec *pvec = &get_cpu_var(lru_add_pvecs);
+       struct zone *zone = page_zone(page);
 
-       if (pagevec_count(pvec))
-               __pagevec_lru_add(pvec);
-       pvec = &__get_cpu_var(lru_add_active_pvecs);
-       if (pagevec_count(pvec))
-               __pagevec_lru_add_active(pvec);
-       put_cpu_var(lru_add_pvecs);
+       spin_lock_irq(&zone->lru_lock);
+       SetPageUnevictable(page);
+       SetPageLRU(page);
+       add_page_to_lru_list(zone, page, LRU_UNEVICTABLE);
+       spin_unlock_irq(&zone->lru_lock);
 }
 
 /*
- * This path almost never happens for VM activity - pages are normally
- * freed via pagevecs.  But it gets used by networking.
+ * If the page can not be invalidated, it is moved to the
+ * inactive list to speed up its reclaim.  It is moved to the
+ * head of the list, rather than the tail, to give the flusher
+ * threads some time to write it out, as this is much more
+ * effective than the single-page writeout from reclaim.
+ *
+ * If the page isn't page_mapped and dirty/writeback, the page
+ * could reclaim asap using PG_reclaim.
+ *
+ * 1. active, mapped page -> none
+ * 2. active, dirty/writeback page -> inactive, head, PG_reclaim
+ * 3. inactive, mapped page -> none
+ * 4. inactive, dirty/writeback page -> inactive, head, PG_reclaim
+ * 5. inactive, clean -> inactive, tail
+ * 6. Others -> none
+ *
+ * In 4, why it moves inactive's head, the VM expects the page would
+ * be write it out by flusher threads as this is much more effective
+ * than the single-page writeout from reclaim.
  */
-void fastcall __page_cache_release(struct page *page)
+static void lru_deactivate_fn(struct page *page, void *arg)
 {
-       unsigned long flags;
+       int lru, file;
+       bool active;
        struct zone *zone = page_zone(page);
 
-       spin_lock_irqsave(&zone->lru_lock, flags);
-       if (TestClearPageLRU(page))
-               del_page_from_lru(zone, page);
-       if (page_count(page) != 0)
-               page = NULL;
-       spin_unlock_irqrestore(&zone->lru_lock, flags);
-       if (page)
-               free_hot_page(page);
+       if (!PageLRU(page))
+               return;
+
+       if (PageUnevictable(page))
+               return;
+
+       /* Some processes are using the page */
+       if (page_mapped(page))
+               return;
+
+       active = PageActive(page);
+
+       file = page_is_file_cache(page);
+       lru = page_lru_base_type(page);
+       del_page_from_lru_list(zone, page, lru + active);
+       ClearPageActive(page);
+       ClearPageReferenced(page);
+       add_page_to_lru_list(zone, page, lru);
+
+       if (PageWriteback(page) || PageDirty(page)) {
+               /*
+                * PG_reclaim could be raced with end_page_writeback
+                * It can make readahead confusing.  But race window
+                * is _really_ small and  it's non-critical problem.
+                */
+               SetPageReclaim(page);
+       } else {
+               struct lruvec *lruvec;
+               /*
+                * The page's writeback ends up during pagevec
+                * We moves tha page into tail of inactive.
+                */
+               lruvec = mem_cgroup_lru_move_lists(zone, page, lru, lru);
+               list_move_tail(&page->lru, &lruvec->lists[lru]);
+               __count_vm_event(PGROTATED);
+       }
+
+       if (active)
+               __count_vm_event(PGDEACTIVATE);
+       update_page_reclaim_stat(zone, page, file, 0);
+}
+
+/*
+ * Drain pages out of the cpu's pagevecs.
+ * Either "cpu" is the current CPU, and preemption has already been
+ * disabled; or "cpu" is being hot-unplugged, and is already dead.
+ */
+void lru_add_drain_cpu(int cpu)
+{
+       struct pagevec *pvecs = per_cpu(lru_add_pvecs, cpu);
+       struct pagevec *pvec;
+       int lru;
+
+       for_each_lru(lru) {
+               pvec = &pvecs[lru - LRU_BASE];
+               if (pagevec_count(pvec))
+                       __pagevec_lru_add(pvec, lru);
+       }
+
+       pvec = &per_cpu(lru_rotate_pvecs, cpu);
+       if (pagevec_count(pvec)) {
+               unsigned long flags;
+
+               /* No harm done if a racing interrupt already did this */
+               local_irq_save(flags);
+               pagevec_move_tail(pvec);
+               local_irq_restore(flags);
+       }
+
+       pvec = &per_cpu(lru_deactivate_pvecs, cpu);
+       if (pagevec_count(pvec))
+               pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL);
+
+       activate_page_drain(cpu);
+}
+
+/**
+ * deactivate_page - forcefully deactivate a page
+ * @page: page to deactivate
+ *
+ * This function hints the VM that @page is a good reclaim candidate,
+ * for example if its invalidation fails due to the page being dirty
+ * or under writeback.
+ */
+void deactivate_page(struct page *page)
+{
+       /*
+        * In a workload with many unevictable page such as mprotect, unevictable
+        * page deactivation for accelerating reclaim is pointless.
+        */
+       if (PageUnevictable(page))
+               return;
+
+       if (likely(get_page_unless_zero(page))) {
+               struct pagevec *pvec = &get_cpu_var(lru_deactivate_pvecs);
+
+               if (!pagevec_add(pvec, page))
+                       pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL);
+               put_cpu_var(lru_deactivate_pvecs);
+       }
+}
+
+void lru_add_drain(void)
+{
+       lru_add_drain_cpu(get_cpu());
+       put_cpu();
+}
+
+static void lru_add_drain_per_cpu(struct work_struct *dummy)
+{
+       lru_add_drain();
 }
 
-EXPORT_SYMBOL(__page_cache_release);
+/*
+ * Returns 0 for success
+ */
+int lru_add_drain_all(void)
+{
+       return schedule_on_each_cpu(lru_add_drain_per_cpu);
+}
 
 /*
  * Batched page_cache_release().  Decrement the reference count on all the
@@ -200,47 +578,56 @@ EXPORT_SYMBOL(__page_cache_release);
  * Avoid taking zone->lru_lock if possible, but if it is taken, retain it
  * for the remainder of the operation.
  *
- * The locking in this function is against shrink_cache(): we recheck the
- * page count inside the lock to see whether shrink_cache grabbed the page
- * via the LRU.  If it did, give up: shrink_cache will free it.
+ * The locking in this function is against shrink_inactive_list(): we recheck
+ * the page count inside the lock to see whether shrink_inactive_list()
+ * grabbed the page via the LRU.  If it did, give up: shrink_inactive_list()
+ * will free it.
  */
 void release_pages(struct page **pages, int nr, int cold)
 {
        int i;
-       struct pagevec pages_to_free;
+       LIST_HEAD(pages_to_free);
        struct zone *zone = NULL;
+       unsigned long uninitialized_var(flags);
 
-       pagevec_init(&pages_to_free, cold);
        for (i = 0; i < nr; i++) {
                struct page *page = pages[i];
-               struct zone *pagezone;
+
+               if (unlikely(PageCompound(page))) {
+                       if (zone) {
+                               spin_unlock_irqrestore(&zone->lru_lock, flags);
+                               zone = NULL;
+                       }
+                       put_compound_page(page);
+                       continue;
+               }
 
                if (!put_page_testzero(page))
                        continue;
 
-               pagezone = page_zone(page);
-               if (pagezone != zone) {
-                       if (zone)
-                               spin_unlock_irq(&zone->lru_lock);
-                       zone = pagezone;
-                       spin_lock_irq(&zone->lru_lock);
-               }
-               if (TestClearPageLRU(page))
-                       del_page_from_lru(zone, page);
-               if (page_count(page) == 0) {
-                       if (!pagevec_add(&pages_to_free, page)) {
-                               spin_unlock_irq(&zone->lru_lock);
-                               __pagevec_free(&pages_to_free);
-                               pagevec_reinit(&pages_to_free);
-                               zone = NULL;    /* No lock is held */
+               if (PageLRU(page)) {
+                       struct zone *pagezone = page_zone(page);
+
+                       if (pagezone != zone) {
+                               if (zone)
+                                       spin_unlock_irqrestore(&zone->lru_lock,
+                                                                       flags);
+                               zone = pagezone;
+                               spin_lock_irqsave(&zone->lru_lock, flags);
                        }
+                       VM_BUG_ON(!PageLRU(page));
+                       __ClearPageLRU(page);
+                       del_page_from_lru_list(zone, page, page_off_lru(page));
                }
+
+               list_add(&page->lru, &pages_to_free);
        }
        if (zone)
-               spin_unlock_irq(&zone->lru_lock);
+               spin_unlock_irqrestore(&zone->lru_lock, flags);
 
-       pagevec_free(&pages_to_free);
+       free_hot_cold_page_list(&pages_to_free, cold);
 }
+EXPORT_SYMBOL(release_pages);
 
 /*
  * The pages which we're about to release may be in the deferred lru-addition
@@ -258,104 +645,88 @@ void __pagevec_release(struct pagevec *pvec)
        release_pages(pvec->pages, pagevec_count(pvec), pvec->cold);
        pagevec_reinit(pvec);
 }
+EXPORT_SYMBOL(__pagevec_release);
 
-/*
- * pagevec_release() for pages which are known to not be on the LRU
- *
- * This function reinitialises the caller's pagevec.
- */
-void __pagevec_release_nonlru(struct pagevec *pvec)
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+/* used by __split_huge_page_refcount() */
+void lru_add_page_tail(struct zone* zone,
+                      struct page *page, struct page *page_tail)
 {
-       int i;
-       struct pagevec pages_to_free;
-
-       pagevec_init(&pages_to_free, pvec->cold);
-       pages_to_free.cold = pvec->cold;
-       for (i = 0; i < pagevec_count(pvec); i++) {
-               struct page *page = pvec->pages[i];
-
-               BUG_ON(PageLRU(page));
-               if (put_page_testzero(page))
-                       pagevec_add(&pages_to_free, page);
+       int uninitialized_var(active);
+       enum lru_list lru;
+       const int file = 0;
+
+       VM_BUG_ON(!PageHead(page));
+       VM_BUG_ON(PageCompound(page_tail));
+       VM_BUG_ON(PageLRU(page_tail));
+       VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&zone->lru_lock));
+
+       SetPageLRU(page_tail);
+
+       if (page_evictable(page_tail, NULL)) {
+               if (PageActive(page)) {
+                       SetPageActive(page_tail);
+                       active = 1;
+                       lru = LRU_ACTIVE_ANON;
+               } else {
+                       active = 0;
+                       lru = LRU_INACTIVE_ANON;
+               }
+       } else {
+               SetPageUnevictable(page_tail);
+               lru = LRU_UNEVICTABLE;
        }
-       pagevec_free(&pages_to_free);
-       pagevec_reinit(pvec);
-}
 
-/*
- * Add the passed pages to the LRU, then drop the caller's refcount
- * on them.  Reinitialises the caller's pagevec.
- */
-void __pagevec_lru_add(struct pagevec *pvec)
-{
-       int i;
-       struct zone *zone = NULL;
-
-       for (i = 0; i < pagevec_count(pvec); i++) {
-               struct page *page = pvec->pages[i];
-               struct zone *pagezone = page_zone(page);
-
-               if (pagezone != zone) {
-                       if (zone)
-                               spin_unlock_irq(&zone->lru_lock);
-                       zone = pagezone;
-                       spin_lock_irq(&zone->lru_lock);
-               }
-               if (TestSetPageLRU(page))
-                       BUG();
-               add_page_to_inactive_list(zone, page);
+       if (likely(PageLRU(page)))
+               list_add_tail(&page_tail->lru, &page->lru);
+       else {
+               struct list_head *list_head;
+               /*
+                * Head page has not yet been counted, as an hpage,
+                * so we must account for each subpage individually.
+                *
+                * Use the standard add function to put page_tail on the list,
+                * but then correct its position so they all end up in order.
+                */
+               add_page_to_lru_list(zone, page_tail, lru);
+               list_head = page_tail->lru.prev;
+               list_move_tail(&page_tail->lru, list_head);
        }
-       if (zone)
-               spin_unlock_irq(&zone->lru_lock);
-       release_pages(pvec->pages, pvec->nr, pvec->cold);
-       pagevec_reinit(pvec);
-}
 
-EXPORT_SYMBOL(__pagevec_lru_add);
+       if (!PageUnevictable(page))
+               update_page_reclaim_stat(zone, page_tail, file, active);
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
-void __pagevec_lru_add_active(struct pagevec *pvec)
+static void __pagevec_lru_add_fn(struct page *page, void *arg)
 {
-       int i;
-       struct zone *zone = NULL;
+       enum lru_list lru = (enum lru_list)arg;
+       struct zone *zone = page_zone(page);
+       int file = is_file_lru(lru);
+       int active = is_active_lru(lru);
 
-       for (i = 0; i < pagevec_count(pvec); i++) {
-               struct page *page = pvec->pages[i];
-               struct zone *pagezone = page_zone(page);
+       VM_BUG_ON(PageActive(page));
+       VM_BUG_ON(PageUnevictable(page));
+       VM_BUG_ON(PageLRU(page));
 
-               if (pagezone != zone) {
-                       if (zone)
-                               spin_unlock_irq(&zone->lru_lock);
-                       zone = pagezone;
-                       spin_lock_irq(&zone->lru_lock);
-               }
-               if (TestSetPageLRU(page))
-                       BUG();
-               if (TestSetPageActive(page))
-                       BUG();
-               add_page_to_active_list(zone, page);
-       }
-       if (zone)
-               spin_unlock_irq(&zone->lru_lock);
-       release_pages(pvec->pages, pvec->nr, pvec->cold);
-       pagevec_reinit(pvec);
+       SetPageLRU(page);
+       if (active)
+               SetPageActive(page);
+       add_page_to_lru_list(zone, page, lru);
+       update_page_reclaim_stat(zone, page, file, active);
 }
 
 /*
- * Try to drop buffers from the pages in a pagevec
+ * Add the passed pages to the LRU, then drop the caller's refcount
+ * on them.  Reinitialises the caller's pagevec.
  */
-void pagevec_strip(struct pagevec *pvec)
+void __pagevec_lru_add(struct pagevec *pvec, enum lru_list lru)
 {
-       int i;
+       VM_BUG_ON(is_unevictable_lru(lru));
 
-       for (i = 0; i < pagevec_count(pvec); i++) {
-               struct page *page = pvec->pages[i];
-
-               if (PagePrivate(page) && !TestSetPageLocked(page)) {
-                       try_to_release_page(page, 0);
-                       unlock_page(page);
-               }
-       }
+       pagevec_lru_move_fn(pvec, __pagevec_lru_add_fn, (void *)lru);
 }
+EXPORT_SYMBOL(__pagevec_lru_add);
 
 /**
  * pagevec_lookup - gang pagecache lookup
@@ -379,6 +750,7 @@ unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping,
        pvec->nr = find_get_pages(mapping, start, nr_pages, pvec->pages);
        return pagevec_count(pvec);
 }
+EXPORT_SYMBOL(pagevec_lookup);
 
 unsigned pagevec_lookup_tag(struct pagevec *pvec, struct address_space *mapping,
                pgoff_t *index, int tag, unsigned nr_pages)
@@ -387,90 +759,18 @@ unsigned pagevec_lookup_tag(struct pagevec *pvec, struct address_space *mapping,
                                        nr_pages, pvec->pages);
        return pagevec_count(pvec);
 }
-
-
-#ifdef CONFIG_SMP
-/*
- * We tolerate a little inaccuracy to avoid ping-ponging the counter between
- * CPUs
- */
-#define ACCT_THRESHOLD max(16, NR_CPUS * 2)
-
-static DEFINE_PER_CPU(long, committed_space) = 0;
-
-void vm_acct_memory(long pages)
-{
-       long *local;
-
-       preempt_disable();
-       local = &__get_cpu_var(committed_space);
-       *local += pages;
-       if (*local > ACCT_THRESHOLD || *local < -ACCT_THRESHOLD) {
-               atomic_add(*local, &vm_committed_space);
-               *local = 0;
-       }
-       preempt_enable();
-}
-EXPORT_SYMBOL(vm_acct_memory);
-
-#ifdef CONFIG_HOTPLUG_CPU
-static void lru_drain_cache(unsigned int cpu)
-{
-       struct pagevec *pvec = &per_cpu(lru_add_pvecs, cpu);
-
-       /* CPU is dead, so no locking needed. */
-       if (pagevec_count(pvec))
-               __pagevec_lru_add(pvec);
-       pvec = &per_cpu(lru_add_active_pvecs, cpu);
-       if (pagevec_count(pvec))
-               __pagevec_lru_add_active(pvec);
-}
-
-/* Drop the CPU's cached committed space back into the central pool. */
-static int cpu_swap_callback(struct notifier_block *nfb,
-                            unsigned long action,
-                            void *hcpu)
-{
-       long *committed;
-
-       committed = &per_cpu(committed_space, (long)hcpu);
-       if (action == CPU_DEAD) {
-               atomic_add(*committed, &vm_committed_space);
-               *committed = 0;
-               lru_drain_cache((long)hcpu);
-       }
-       return NOTIFY_OK;
-}
-#endif /* CONFIG_HOTPLUG_CPU */
-#endif /* CONFIG_SMP */
-
-#ifdef CONFIG_SMP
-void percpu_counter_mod(struct percpu_counter *fbc, long amount)
-{
-       long count;
-       long *pcount;
-       int cpu = get_cpu();
-
-       pcount = per_cpu_ptr(fbc->counters, cpu);
-       count = *pcount + amount;
-       if (count >= FBC_BATCH || count <= -FBC_BATCH) {
-               spin_lock(&fbc->lock);
-               fbc->count += count;
-               spin_unlock(&fbc->lock);
-               count = 0;
-       }
-       *pcount = count;
-       put_cpu();
-}
-EXPORT_SYMBOL(percpu_counter_mod);
-#endif
+EXPORT_SYMBOL(pagevec_lookup_tag);
 
 /*
  * Perform any setup for the swap system
  */
 void __init swap_setup(void)
 {
-       unsigned long megs = num_physpages >> (20 - PAGE_SHIFT);
+       unsigned long megs = totalram_pages >> (20 - PAGE_SHIFT);
+
+#ifdef CONFIG_SWAP
+       bdi_init(swapper_space.backing_dev_info);
+#endif
 
        /* Use a smaller cluster for small-memory machines */
        if (megs < 16)
@@ -481,5 +781,4 @@ void __init swap_setup(void)
         * Right now other parts of the system means that we
         * _really_ don't want to cluster much more
         */
-       hotcpu_notifier(cpu_swap_callback, 0);
 }