vmscan: split LRU lists into anon & file sets

Split the LRU lists in two, one set for pages that are backed by real file
systems ("file") and one for pages that are backed by memory and swap
("anon").  The latter includes tmpfs.

The advantage of doing this is that the VM will not have to scan over lots
of anonymous pages (which we generally do not want to swap out), just to
find the page cache pages that it should evict.

This patch has the infrastructure and a basic policy to balance how much
we scan the anon lists and how much we scan the file lists.  The big
policy changes are in separate patches.

[lee.schermerhorn@hp.com: collect lru meminfo statistics from correct offset]
[kosaki.motohiro@jp.fujitsu.com: prevent incorrect oom under split_lru]
[kosaki.motohiro@jp.fujitsu.com: fix pagevec_move_tail() doesn't treat unevictable page]
[hugh@veritas.com: memcg swapbacked pages active]
[hugh@veritas.com: splitlru: BDI_CAP_SWAP_BACKED]
[akpm@linux-foundation.org: fix /proc/vmstat units]
[nishimura@mxp.nes.nec.co.jp: memcg: fix handling of shmem migration]
[kosaki.motohiro@jp.fujitsu.com: adjust Quicklists field of /proc/meminfo]
[kosaki.motohiro@jp.fujitsu.com: fix style issue of get_scan_ratio()]
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 5 deletions

diff --git a/mm/vmstat.c b/mm/vmstat.c
index 52c0335c1b71..27400b7da7c4 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -619,8 +619,10 @@ const struct seq_operations pagetypeinfo_op = {
 static const char * const vmstat_text[] = {
         /* Zoned VM counters */
         "nr_free_pages",
-        "nr_inactive",
-        "nr_active",
+        "nr_inactive_anon",
+        "nr_active_anon",
+        "nr_inactive_file",
+        "nr_active_file",
         "nr_anon_pages",
         "nr_mapped",
         "nr_file_pages",
@@ -688,7 +690,7 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
                    "\n        min      %lu"
                    "\n        low      %lu"
                    "\n        high     %lu"
-                   "\n        scanned  %lu (a: %lu i: %lu)"
+                   "\n        scanned  %lu (aa: %lu ia: %lu af: %lu if: %lu)"
                    "\n        spanned  %lu"
                    "\n        present  %lu",
                    zone_page_state(zone, NR_FREE_PAGES),
@@ -696,8 +698,10 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
                    zone->pages_low,
                    zone->pages_high,
                    zone->pages_scanned,
-                   zone->lru[LRU_ACTIVE].nr_scan,
-                   zone->lru[LRU_INACTIVE].nr_scan,
+                   zone->lru[LRU_ACTIVE_ANON].nr_scan,
+                   zone->lru[LRU_INACTIVE_ANON].nr_scan,
+                   zone->lru[LRU_ACTIVE_FILE].nr_scan,
+                   zone->lru[LRU_INACTIVE_FILE].nr_scan,
                    zone->spanned_pages,
                    zone->present_pages);