[PATCH] zoned vm counters: convert nr_mapped to per zone counter

nr_mapped is important because it allows a determination of how many pages of
a zone are not mapped, which would allow a more efficient means of determining
when we need to reclaim memory in a zone.

We take the nr_mapped field out of the page state structure and define a new
per zone counter named NR_FILE_MAPPED (the anonymous pages will be split off
from NR_MAPPED in the next patch).

We replace the use of nr_mapped in various kernel locations.  This avoids the
looping over all processors in try_to_free_pages(), writeback, reclaim (swap +
zone reclaim).

[akpm@osdl.org: bugfix]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c
index 5c10ea1..bc7d9ab 100644
--- a/fs/proc/proc_misc.c
+++ b/fs/proc/proc_misc.c
@@ -190,7 +190,7 @@
 		K(i.freeswap),
 		K(ps.nr_dirty),
 		K(ps.nr_writeback),
-		K(ps.nr_mapped),
+		K(global_page_state(NR_FILE_MAPPED)),
 		K(ps.nr_slab),
 		K(allowed),
 		K(committed),