1 files changed, 26 insertions, 34 deletions

diff --git a/mm/rmap.c b/mm/rmap.c
index 1099394..ac4af8c 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)--;