aboutsummaryrefslogtreecommitdiff
path: root/mm/compaction.c
diff options
context:
space:
mode:
authorMel Gorman <mel@csn.ul.ie>2010-05-24 14:32:28 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-25 08:06:59 -0700
commit76ab0f530e4a01d4dc20cdc1d5e87753c579dc18 (patch)
tree8e1566df85e02f67876685c36d217fec4845f79f /mm/compaction.c
parent748446bb6b5a9390b546af38ec899c868a9dbcf0 (diff)
downloadvexpress-lsk-76ab0f530e4a01d4dc20cdc1d5e87753c579dc18.tar.gz
mm: compaction: add /proc trigger for memory compaction
Add a proc file /proc/sys/vm/compact_memory. When an arbitrary value is written to the file, all zones are compacted. The expected user of such a trigger is a job scheduler that prepares the system before the target application runs. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Rik van Riel <riel@redhat.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/compaction.c')
-rw-r--r--mm/compaction.c62
1 files changed, 62 insertions, 0 deletions
diff --git a/mm/compaction.c b/mm/compaction.c
index be1ff3f7552..77854fbc0f5 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -12,6 +12,7 @@
#include <linux/compaction.h>
#include <linux/mm_inline.h>
#include <linux/backing-dev.h>
+#include <linux/sysctl.h>
#include "internal.h"
/*
@@ -391,3 +392,64 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
return ret;
}
+
+/* Compact all zones within a node */
+static int compact_node(int nid)
+{
+ int zoneid;
+ pg_data_t *pgdat;
+ struct zone *zone;
+
+ if (nid < 0 || nid >= nr_node_ids || !node_online(nid))
+ return -EINVAL;
+ pgdat = NODE_DATA(nid);
+
+ /* Flush pending updates to the LRU lists */
+ lru_add_drain_all();
+
+ for (zoneid = 0; zoneid < MAX_NR_ZONES; zoneid++) {
+ struct compact_control cc = {
+ .nr_freepages = 0,
+ .nr_migratepages = 0,
+ };
+
+ zone = &pgdat->node_zones[zoneid];
+ if (!populated_zone(zone))
+ continue;
+
+ cc.zone = zone;
+ INIT_LIST_HEAD(&cc.freepages);
+ INIT_LIST_HEAD(&cc.migratepages);
+
+ compact_zone(zone, &cc);
+
+ VM_BUG_ON(!list_empty(&cc.freepages));
+ VM_BUG_ON(!list_empty(&cc.migratepages));
+ }
+
+ return 0;
+}
+
+/* Compact all nodes in the system */
+static int compact_nodes(void)
+{
+ int nid;
+
+ for_each_online_node(nid)
+ compact_node(nid);
+
+ return COMPACT_COMPLETE;
+}
+
+/* The written value is actually unused, all memory is compacted */
+int sysctl_compact_memory;
+
+/* This is the entry point for compacting all nodes via /proc/sys/vm */
+int sysctl_compaction_handler(struct ctl_table *table, int write,
+ void __user *buffer, size_t *length, loff_t *ppos)
+{
+ if (write)
+ return compact_nodes();
+
+ return 0;
+}