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authorMel Gorman <mel@csn.ul.ie>2010-05-24 17:32:28 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-25 11:06:59 -0400
commit76ab0f530e4a01d4dc20cdc1d5e87753c579dc18 (patch)
tree8e1566df85e02f67876685c36d217fec4845f79f /mm/compaction.c
parent748446bb6b5a9390b546af38ec899c868a9dbcf0 (diff)
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 be1ff3f7552b..77854fbc0f56 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -12,6 +12,7 @@
12#include <linux/compaction.h> 12#include <linux/compaction.h>
13#include <linux/mm_inline.h> 13#include <linux/mm_inline.h>
14#include <linux/backing-dev.h> 14#include <linux/backing-dev.h>
15#include <linux/sysctl.h>
15#include "internal.h" 16#include "internal.h"
16 17
17/* 18/*
@@ -391,3 +392,64 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
391 392
392 return ret; 393 return ret;
393} 394}
395
396/* Compact all zones within a node */
397static int compact_node(int nid)
398{
399 int zoneid;
400 pg_data_t *pgdat;
401 struct zone *zone;
402
403 if (nid < 0 || nid >= nr_node_ids || !node_online(nid))
404 return -EINVAL;
405 pgdat = NODE_DATA(nid);
406
407 /* Flush pending updates to the LRU lists */
408 lru_add_drain_all();
409
410 for (zoneid = 0; zoneid < MAX_NR_ZONES; zoneid++) {
411 struct compact_control cc = {
412 .nr_freepages = 0,
413 .nr_migratepages = 0,
414 };
415
416 zone = &pgdat->node_zones[zoneid];
417 if (!populated_zone(zone))
418 continue;
419
420 cc.zone = zone;
421 INIT_LIST_HEAD(&cc.freepages);
422 INIT_LIST_HEAD(&cc.migratepages);
423
424 compact_zone(zone, &cc);
425
426 VM_BUG_ON(!list_empty(&cc.freepages));
427 VM_BUG_ON(!list_empty(&cc.migratepages));
428 }
429
430 return 0;
431}
432
433/* Compact all nodes in the system */
434static int compact_nodes(void)
435{
436 int nid;
437
438 for_each_online_node(nid)
439 compact_node(nid);
440
441 return COMPACT_COMPLETE;
442}
443
444/* The written value is actually unused, all memory is compacted */
445int sysctl_compact_memory;
446
447/* This is the entry point for compacting all nodes via /proc/sys/vm */
448int sysctl_compaction_handler(struct ctl_table *table, int write,
449 void __user *buffer, size_t *length, loff_t *ppos)
450{
451 if (write)
452 return compact_nodes();
453
454 return 0;
455}