1 files changed, 26 insertions, 34 deletions

diff --git a/mm/rmap.c b/mm/rmap.c
index 10993942d6c9..ac4af8cffbf9 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -47,9 +47,9 @@
 #include <linux/rmap.h>
 #include <linux/rcupdate.h>
 #include <linux/module.h>
-#include <linux/kallsyms.h>
 #include <linux/memcontrol.h>
 #include <linux/mmu_notifier.h>
+#include <linux/migrate.h>
 
 #include <asm/tlbflush.h>
 
@@ -191,7 +191,7 @@ void __init anon_vma_init(void)
  * Getting a lock on a stable anon_vma from a page off the LRU is
  * tricky: page_lock_anon_vma rely on RCU to guard against the races.
  */
-struct anon_vma *page_lock_anon_vma(struct page *page)
+static struct anon_vma *page_lock_anon_vma(struct page *page)
 {
         struct anon_vma *anon_vma;
         unsigned long anon_mapping;
@@ -211,7 +211,7 @@ out:
         return NULL;
 }
 
-void page_unlock_anon_vma(struct anon_vma *anon_vma)
+static void page_unlock_anon_vma(struct anon_vma *anon_vma)
 {
         spin_unlock(&anon_vma->lock);
         rcu_read_unlock();
@@ -359,8 +359,17 @@ static int page_referenced_one(struct page *page,
                 goto out_unmap;
         }
 
-        if (ptep_clear_flush_young_notify(vma, address, pte))
-                referenced++;
+        if (ptep_clear_flush_young_notify(vma, address, pte)) {
+                /*
+                 * Don't treat a reference through a sequentially read
+                 * mapping as such.  If the page has been used in
+                 * another mapping, we will catch it; if this other
+                 * mapping is already gone, the unmap path will have
+                 * set PG_referenced or activated the page.
+                 */
+                if (likely(!VM_SequentialReadHint(vma)))
+                        referenced++;
+        }
 
         /* Pretend the page is referenced if the task has the
            swap token and is in the middle of a page fault. */
@@ -661,9 +670,14 @@ void page_add_anon_rmap(struct page *page,
 void page_add_new_anon_rmap(struct page *page,
         struct vm_area_struct *vma, unsigned long address)
 {
-        BUG_ON(address < vma->vm_start || address >= vma->vm_end);
-        atomic_set(&page->_mapcount, 0); /* elevate count by 1 (starts at -1) */
+        VM_BUG_ON(address < vma->vm_start || address >= vma->vm_end);
+        SetPageSwapBacked(page);
+        atomic_set(&page->_mapcount, 0); /* increment count (starts at -1) */
         __page_set_anon_rmap(page, vma, address);
+        if (page_evictable(page, vma))
+                lru_cache_add_lru(page, LRU_ACTIVE_ANON);
+        else
+                add_page_to_unevictable_list(page);
 }
 
 /**
@@ -693,7 +707,6 @@ void page_add_file_rmap(struct page *page)
  */
 void page_dup_rmap(struct page *page, struct vm_area_struct *vma, unsigned long address)
 {
-        BUG_ON(page_mapcount(page) == 0);
         if (PageAnon(page))
                 __page_check_anon_rmap(page, vma, address);
         atomic_inc(&page->_mapcount);
@@ -703,28 +716,12 @@ void page_dup_rmap(struct page *page, struct vm_area_struct *vma, unsigned long
 /**
  * page_remove_rmap - take down pte mapping from a page
  * @page: page to remove mapping from
- * @vma: the vm area in which the mapping is removed
  *
  * The caller needs to hold the pte lock.
  */
-void page_remove_rmap(struct page *page, struct vm_area_struct *vma)
+void page_remove_rmap(struct page *page)
 {
         if (atomic_add_negative(-1, &page->_mapcount)) {
-                if (unlikely(page_mapcount(page) < 0)) {
-                        printk (KERN_EMERG "Eeek! page_mapcount(page) went negative! (%d)\n", page_mapcount(page));
-                        printk (KERN_EMERG "  page pfn = %lx\n", page_to_pfn(page));
-                        printk (KERN_EMERG "  page->flags = %lx\n", page->flags);
-                        printk (KERN_EMERG "  page->count = %x\n", page_count(page));
-                        printk (KERN_EMERG "  page->mapping = %p\n", page->mapping);
-                        print_symbol (KERN_EMERG "  vma->vm_ops = %s\n", (unsigned long)vma->vm_ops);
-                        if (vma->vm_ops) {
-                                print_symbol (KERN_EMERG "  vma->vm_ops->fault = %s\n", (unsigned long)vma->vm_ops->fault);
-                        }
-                        if (vma->vm_file && vma->vm_file->f_op)
-                                print_symbol (KERN_EMERG "  vma->vm_file->f_op->mmap = %s\n", (unsigned long)vma->vm_file->f_op->mmap);
-                        BUG();
-                }
-
                 /*
                  * Now that the last pte has gone, s390 must transfer dirty
                  * flag from storage key to struct page.  We can usually skip
@@ -818,8 +815,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
                                 spin_unlock(&mmlist_lock);
                         }
                         dec_mm_counter(mm, anon_rss);
-#ifdef CONFIG_MIGRATION
-                } else {
+                } else if (PAGE_MIGRATION) {
                         /*
                          * Store the pfn of the page in a special migration
                          * pte. do_swap_page() will wait until the migration
@@ -827,23 +823,19 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
                          */
                         BUG_ON(!migration);
                         entry = make_migration_entry(page, pte_write(pteval));
-#endif
                 }
                 set_pte_at(mm, address, pte, swp_entry_to_pte(entry));
                 BUG_ON(pte_file(*pte));
-        } else
-#ifdef CONFIG_MIGRATION
-        if (migration) {
+        } else if (PAGE_MIGRATION && migration) {
                 /* Establish migration entry for a file page */
                 swp_entry_t entry;
                 entry = make_migration_entry(page, pte_write(pteval));
                 set_pte_at(mm, address, pte, swp_entry_to_pte(entry));
         } else
-#endif
                 dec_mm_counter(mm, file_rss);
 
 
-        page_remove_rmap(page, vma);
+        page_remove_rmap(page);
         page_cache_release(page);
 
 out_unmap:
@@ -958,7 +950,7 @@ static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount,
                 if (pte_dirty(pteval))
                         set_page_dirty(page);
 
-                page_remove_rmap(page, vma);
+                page_remove_rmap(page);
                 page_cache_release(page);
                 dec_mm_counter(mm, file_rss);
                 (*mapcount)--;