X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=blobdiff_plain;f=mm%2Frmap.c;h=28aafe2b530668b03c766619a83873ee2a91087e;hp=09c3d0b961168b6168a41b47a80e7f2c4774799f;hb=db16826367fefcb0ddb93d76b66adc52eb4e6339;hpb=465fdd97cbe16ef8727221857e96ef62dd352017

diff --git a/mm/rmap.c b/mm/rmap.c
index 09c3d0b..28aafe2 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -715,27 +715,6 @@ void page_add_file_rmap(struct page *page)
 	}
 }
 
-#ifdef CONFIG_DEBUG_VM
-/**
- * page_dup_rmap - duplicate pte mapping to a page
- * @page:	the page to add the mapping to
- * @vma:	the vm area being duplicated
- * @address:	the user virtual address mapped
- *
- * For copy_page_range only: minimal extract from page_add_file_rmap /
- * page_add_anon_rmap, avoiding unnecessary tests (already checked) so it's
- * quicker.
- *
- * The caller needs to hold the pte lock.
- */
-void page_dup_rmap(struct page *page, struct vm_area_struct *vma, unsigned long address)
-{
-	if (PageAnon(page))
-		__page_check_anon_rmap(page, vma, address);
-	atomic_inc(&page->_mapcount);
-}
-#endif
-
 /**
  * page_remove_rmap - take down pte mapping from a page
  * @page: page to remove mapping from
@@ -744,34 +723,37 @@ void page_dup_rmap(struct page *page, struct vm_area_struct *vma, unsigned long
  */
 void page_remove_rmap(struct page *page)
 {
-	if (atomic_add_negative(-1, &page->_mapcount)) {
-		/*
-		 * Now that the last pte has gone, s390 must transfer dirty
-		 * flag from storage key to struct page.  We can usually skip
-		 * this if the page is anon, so about to be freed; but perhaps
-		 * not if it's in swapcache - there might be another pte slot
-		 * containing the swap entry, but page not yet written to swap.
-		 */
-		if ((!PageAnon(page) || PageSwapCache(page)) &&
-		    page_test_dirty(page)) {
-			page_clear_dirty(page);
-			set_page_dirty(page);
-		}
-		if (PageAnon(page))
-			mem_cgroup_uncharge_page(page);
-		__dec_zone_page_state(page,
-			PageAnon(page) ? NR_ANON_PAGES : NR_FILE_MAPPED);
-		mem_cgroup_update_mapped_file_stat(page, -1);
-		/*
-		 * It would be tidy to reset the PageAnon mapping here,
-		 * but that might overwrite a racing page_add_anon_rmap
-		 * which increments mapcount after us but sets mapping
-		 * before us: so leave the reset to free_hot_cold_page,
-		 * and remember that it's only reliable while mapped.
-		 * Leaving it set also helps swapoff to reinstate ptes
-		 * faster for those pages still in swapcache.
-		 */
+	/* page still mapped by someone else? */
+	if (!atomic_add_negative(-1, &page->_mapcount))
+		return;
+
+	/*
+	 * Now that the last pte has gone, s390 must transfer dirty
+	 * flag from storage key to struct page.  We can usually skip
+	 * this if the page is anon, so about to be freed; but perhaps
+	 * not if it's in swapcache - there might be another pte slot
+	 * containing the swap entry, but page not yet written to swap.
+	 */
+	if ((!PageAnon(page) || PageSwapCache(page)) && page_test_dirty(page)) {
+		page_clear_dirty(page);
+		set_page_dirty(page);
 	}
+	if (PageAnon(page)) {
+		mem_cgroup_uncharge_page(page);
+		__dec_zone_page_state(page, NR_ANON_PAGES);
+	} else {
+		__dec_zone_page_state(page, NR_FILE_MAPPED);
+	}
+	mem_cgroup_update_mapped_file_stat(page, -1);
+	/*
+	 * It would be tidy to reset the PageAnon mapping here,
+	 * but that might overwrite a racing page_add_anon_rmap
+	 * which increments mapcount after us but sets mapping
+	 * before us: so leave the reset to free_hot_cold_page,
+	 * and remember that it's only reliable while mapped.
+	 * Leaving it set also helps swapoff to reinstate ptes
+	 * faster for those pages still in swapcache.
+	 */
 }
 
 /*