[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>

1 files changed, 1 insertions, 1 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 3a877fecc300..04dd2b01b2b7 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1319,7 +1319,7 @@ void show_free_areas(void)
                 ps.nr_unstable,
                 nr_free_pages(),
                 ps.nr_slab,
-                ps.nr_mapped,
+                global_page_state(NR_FILE_MAPPED),
                 ps.nr_page_table_pages);
 
         for_each_zone(zone) {