[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/mm/page-writeback.c b/mm/page-writeback.c
index 4ec7026..60c7244 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -111,7 +111,7 @@
{
wbs->nr_dirty = read_page_state(nr_dirty);
wbs->nr_unstable = read_page_state(nr_unstable);
- wbs->nr_mapped = read_page_state(nr_mapped);
+ wbs->nr_mapped = global_page_state(NR_FILE_MAPPED);
wbs->nr_writeback = read_page_state(nr_writeback);
}