vmscan: unevictable LRU scan sysctl

This patch adds a function to scan individual or all zones' unevictable
lists and move any pages that have become evictable onto the respective
zone's inactive list, where shrink_inactive_list() will deal with them.

Adds sysctl to scan all nodes, and per node attributes to individual
nodes' zones.

Kosaki: If evictable page found in unevictable lru when write
/proc/sys/vm/scan_unevictable_pages, print filename and file offset of
these pages.

[akpm@linux-foundation.org: fix one CONFIG_MMU=n build error]
[kosaki.motohiro@jp.fujitsu.com: adapt vmscan-unevictable-lru-scan-sysctl.patch to new sysfs API]
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/base/node.c b/drivers/base/node.c
index fb45d88a2446..f5207090885a 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -13,6 +13,7 @@
 #include <linux/nodemask.h>
 #include <linux/cpu.h>
 #include <linux/device.h>
+#include <linux/swap.h>
 
 static struct sysdev_class node_class = {
         .name = "node",
@@ -191,6 +192,8 @@ int register_node(struct node *node, int num, struct node *parent)
                 sysdev_create_file(&node->sysdev, &attr_meminfo);
                 sysdev_create_file(&node->sysdev, &attr_numastat);
                 sysdev_create_file(&node->sysdev, &attr_distance);
+
+                scan_unevictable_register_node(node);
         }
         return error;
 }
@@ -210,6 +213,8 @@ void unregister_node(struct node *node)
         sysdev_remove_file(&node->sysdev, &attr_numastat);
         sysdev_remove_file(&node->sysdev, &attr_distance);
 
+        scan_unevictable_unregister_node(node);
+
         sysdev_unregister(&node->sysdev);
 }