memcg: add memcg sanity checks at allocating and freeing pages

Add checks at allocating or freeing a page whether the page is used (iow,
charged) from the view point of memcg.

This check may be useful in debugging a problem and we did similar checks
before the commit 52d4b9ac(memcg: allocate all page_cgroup at boot).

This patch adds some overheads at allocating or freeing memory, so it's
enabled only when CONFIG_DEBUG_VM is enabled.

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 2 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 3a58221f4c22..8e5726ab0d85 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -53,6 +53,7 @@
 #include <linux/compaction.h>
 #include <trace/events/kmem.h>
 #include <linux/ftrace_event.h>
+#include <linux/memcontrol.h>
 
 #include <asm/tlbflush.h>
 #include <asm/div64.h>
@@ -565,7 +566,8 @@ static inline int free_pages_check(struct page *page)
         if (unlikely(page_mapcount(page) |
                 (page->mapping != NULL)  |
                 (atomic_read(&page->_count) != 0) |
-                (page->flags & PAGE_FLAGS_CHECK_AT_FREE))) {
+                (page->flags & PAGE_FLAGS_CHECK_AT_FREE) |
+                (mem_cgroup_bad_page_check(page)))) {
                 bad_page(page);
                 return 1;
         }
@@ -754,7 +756,8 @@ static inline int check_new_page(struct page *page)
         if (unlikely(page_mapcount(page) |
                 (page->mapping != NULL)  |
                 (atomic_read(&page->_count) != 0)  |
-                (page->flags & PAGE_FLAGS_CHECK_AT_PREP))) {
+                (page->flags & PAGE_FLAGS_CHECK_AT_PREP) |
+                (mem_cgroup_bad_page_check(page)))) {
                 bad_page(page);
                 return 1;
         }
@@ -5684,4 +5687,5 @@ void dump_page(struct page *page)
                 page, atomic_read(&page->_count), page_mapcount(page),
                 page->mapping, page->index);
         dump_page_flags(page->flags);
+        mem_cgroup_print_bad_page(page);
 }