[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, 3 deletions

diff --git a/drivers/base/node.c b/drivers/base/node.c
index eae2bdc183bb..8b1232320a99 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -54,8 +54,6 @@ static ssize_t node_read_meminfo(struct sys_device * dev, char * buf)
                 ps.nr_dirty = 0;
         if ((long)ps.nr_writeback < 0)
                 ps.nr_writeback = 0;
-        if ((long)ps.nr_mapped < 0)
-                ps.nr_mapped = 0;
         if ((long)ps.nr_slab < 0)
                 ps.nr_slab = 0;
 
@@ -84,7 +82,7 @@ static ssize_t node_read_meminfo(struct sys_device * dev, char * buf)
                        nid, K(i.freeram - i.freehigh),
                        nid, K(ps.nr_dirty),
                        nid, K(ps.nr_writeback),
-                       nid, K(ps.nr_mapped),
+                       nid, K(node_page_state(nid, NR_FILE_MAPPED)),
                        nid, K(ps.nr_slab));
         n += hugetlb_report_node_meminfo(nid, buf + n);
         return n;