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 <mhocko@suse.cz>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index 8e7577c..a12cc3f 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -153,11 +153,11 @@
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