[PATCH] zoned vm counters: remove NR_FILE_MAPPED from scan control structure

We can now access the number of pages in a mapped state in an inexpensive way
in shrink_active_list.  So drop the nr_mapped field from scan_control.

[akpm@osdl.org: bugfix]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 9 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index d2caf7471cf1..08bc54e80862 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -47,8 +47,6 @@ struct scan_control {
         /* Incremented by the number of inactive pages that were scanned */
         unsigned long nr_scanned;
 
-        unsigned long nr_mapped;        /* From page_state */
-
         /* This context's GFP mask */
         gfp_t gfp_mask;
 
@@ -744,7 +742,8 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
                  * how much memory
                  * is mapped.
                  */
-                mapped_ratio = (sc->nr_mapped * 100) / vm_total_pages;
+                mapped_ratio = (global_page_state(NR_FILE_MAPPED) * 100) /
+                                        vm_total_pages;
 
                 /*
                  * Now decide how much we really want to unmap some pages.  The
@@ -990,7 +989,6 @@ unsigned long try_to_free_pages(struct zone **zones, gfp_t gfp_mask)
         }
 
         for (priority = DEF_PRIORITY; priority >= 0; priority--) {
-                sc.nr_mapped = global_page_state(NR_FILE_MAPPED);
                 sc.nr_scanned = 0;
                 if (!priority)
                         disable_swap_token();
@@ -1075,8 +1073,6 @@ loop_again:
         total_scanned = 0;
         nr_reclaimed = 0;
         sc.may_writepage = !laptop_mode;
-        sc.nr_mapped = global_page_state(NR_FILE_MAPPED);
-
         inc_page_state(pageoutrun);
 
         for (i = 0; i < pgdat->nr_zones; i++) {
@@ -1407,9 +1403,7 @@ unsigned long shrink_all_memory(unsigned long nr_pages)
                 for (prio = DEF_PRIORITY; prio >= 0; prio--) {
                         unsigned long nr_to_scan = nr_pages - ret;
 
-                        sc.nr_mapped = global_page_state(NR_FILE_MAPPED);
                         sc.nr_scanned = 0;
-
                         ret += shrink_all_zones(nr_to_scan, prio, pass, &sc);
                         if (ret >= nr_pages)
                                 goto out;
@@ -1548,7 +1542,6 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
         struct scan_control sc = {
                 .may_writepage = !!(zone_reclaim_mode & RECLAIM_WRITE),
                 .may_swap = !!(zone_reclaim_mode & RECLAIM_SWAP),
-                .nr_mapped = global_page_state(NR_FILE_MAPPED),
                 .swap_cluster_max = max_t(unsigned long, nr_pages,
                                         SWAP_CLUSTER_MAX),
                 .gfp_mask = gfp_mask,