There are a couple of issues with sync_mm_rss(), as added by patch:
Author: KAMEZAWA Hiroyuki <firstname.lastname@example.org>
Date: Fri Mar 5 13:41:40 2010 -0800
Subject: mm: avoid false sharing of mm_counter
(1) You haven't implemented it for NOMMU mode. What's the right way to do
this? Just give an empty function?
(2) linux/mm.h should carry the empty function as an inline when
CONFIG_SPLIT_RSS_COUNTING=n, rather than it being defined as an empty
function in mm/memory.c.