memcg: page_cgroup array is never stored on reserved pages

KAMEZAWA Hiroyuki noted that free_pages_cgroup doesn't have to check for PageReserved because we never store the array on reserved pages (neither alloc_pages_exact nor vmalloc use those pages). So we can replace the check by a BUG_ON. Signed-off-by: Michal Hocko <[email protected]> Acked-by: KAMEZAWA Hiroyuki <[email protected]> Cc: Balbir Singh <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
sum-it · Mar 24, 2011 · 6cfddb2 · 6cfddb2
1 parent dde79e0
commit 6cfddb2
Showing 1 changed file with 5 additions and 5 deletions.
diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
@@ -153,11 +153,11 @@ static void free_page_cgroup(void *addr)
 		vfree(addr);
 	} else {
 		struct page *page = virt_to_page(addr);
-		if (!PageReserved(page)) { /* Is bootmem ? */
-			size_t table_size =
-				sizeof(struct page_cgroup) * PAGES_PER_SECTION;
-			free_pages_exact(addr, table_size);
-		}
+		size_t table_size =
+			sizeof(struct page_cgroup) * PAGES_PER_SECTION;
+
+		BUG_ON(PageReserved(page));
+		free_pages_exact(addr, table_size);
 	}
 }
 #endif