Patch "mm: rmap: fix huge file mmap accounting in the memcg stats" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

mm: rmap: fix huge file mmap accounting in the memcg stats

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
mm-rmap-fix-huge-file-mmap-accounting-in-the-memcg-stats.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Johannes Weiner <[email protected]>
Date: Fri, 31 Mar 2017 15:11:50 -0700
Subject: mm: rmap: fix huge file mmap accounting in the memcg stats

From: Johannes Weiner <[email protected]>

commit 553af430e7c981e6e8fa5007c5b7b5773acc63dd upstream.

Huge pages are accounted as single units in the memcg's "file_mapped" counter. Account the correct number of base pages, like we do in the corresponding node counter.

---
 include/linux/memcontrol.h |    6 ++++++
 mm/rmap.c                  |    4 ++--
 2 files changed, 8 insertions(+), 2 deletions(-)

@@ -739,6 +739,12 @@ static inline bool mem_cgroup_oom_synchr
 	return false;
 }
 
+static inline void mem_cgroup_update_page_stat(struct page *page,
+					       enum mem_cgroup_stat_index idx,
+					       int nr)
+{
+}
+
 static inline void mem_cgroup_inc_page_stat(struct page *page,
 					    enum mem_cgroup_stat_index idx)
 {

@@ -1295,7 +1295,7 @@ void page_add_file_rmap(struct page *pag
 			goto out;
 	}
 	__mod_node_page_state(page_pgdat(page), NR_FILE_MAPPED, nr);
-	mem_cgroup_inc_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED);
+	mem_cgroup_update_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED, nr);
 out:
 	unlock_page_memcg(page);
 }

@@ -1335,7 +1335,7 @@ static void page_remove_file_rmap(struct
 	 * pte lock(a spinlock) is held, which implies preemption disabled.
 	 */
 	__mod_node_page_state(page_pgdat(page), NR_FILE_MAPPED, -nr);
-	mem_cgroup_dec_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED);
+	mem_cgroup_update_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED, -nr);
 
 	if (unlikely(PageMlocked(page)))
 		clear_page_mlock(page);

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/mm-rmap-fix-huge-file-mmap-accounting-in-the-memcg-stats.patch