X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=mm%2Frmap.c;h=059774712c0889fbe1ff08aabc43f7593760baec;hb=ff9bc512f198eb47204f55b24c6fe3d36ed89592;hp=94a5246a3f98b9e9b0ef71172bb184f561c0c294;hpb=3a4b7886ee59e122d359e1714ed89585a06645ad;p=linux-2.6

diff --git a/mm/rmap.c b/mm/rmap.c
index 94a5246a3f..059774712c 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -422,7 +422,7 @@ int page_referenced(struct page *page, int is_locked,
 			referenced += page_referenced_anon(page, mem_cont);
 		else if (is_locked)
 			referenced += page_referenced_file(page, mem_cont);
-		else if (TestSetPageLocked(page))
+		else if (!trylock_page(page))
 			referenced++;
 		else {
 			if (page->mapping)
@@ -659,23 +659,30 @@ void page_remove_rmap(struct page *page, struct vm_area_struct *vma)
 		}
 
 		/*
-		 * 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.
+		 * 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);
 		}
-		mem_cgroup_uncharge_page(page);
 
+		mem_cgroup_uncharge_page(page);
 		__dec_zone_page_state(page,
-				PageAnon(page) ? NR_ANON_PAGES : NR_FILE_MAPPED);
+			PageAnon(page) ? NR_ANON_PAGES : NR_FILE_MAPPED);
+		/*
+		 * 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.
+		 */
 	}
 }