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authorRik van Riel <riel@redhat.com>2012-03-21 16:33:52 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-03-21 17:54:56 -0700
commit7be62de99adcab4449d416977b4274985c5fe023 (patch)
tree20ae021ec9811ad730e6a17a3530d3aa6b5027d0 /mm/compaction.c
parentfe2c2a106663130a5ab45cb0e3414b52df2fff0c (diff)
downloadlinux-7be62de99adcab4449d416977b4274985c5fe023.tar.gz
vmscan: kswapd carefully call compaction
With CONFIG_COMPACTION enabled, kswapd does not try to free contiguous free pages, even when it is woken for a higher order request. This could be bad for eg. jumbo frame network allocations, which are done from interrupt context and cannot compact memory themselves. Higher than before allocation failure rates in the network receive path have been observed in kernels with compaction enabled. Teach kswapd to defragment the memory zones in a node, but only if required and compaction is not deferred in a zone. [akpm@linux-foundation.org: reduce scope of zones_need_compaction] Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Hillf Danton <dhillf@gmail.com> 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.c53
1 files changed, 35 insertions, 18 deletions
diff --git a/mm/compaction.c b/mm/compaction.c
index d9ebebe1a2a..36f0f61f4a2 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -675,44 +675,61 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist,
/* Compact all zones within a node */
-static int compact_node(int nid)
+static int __compact_pgdat(pg_data_t *pgdat, struct compact_control *cc)
{
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,
- .order = -1,
- .sync = true,
- };
zone = &pgdat->node_zones[zoneid];
if (!populated_zone(zone))
continue;
- cc.zone = zone;
- INIT_LIST_HEAD(&cc.freepages);
- INIT_LIST_HEAD(&cc.migratepages);
+ cc->nr_freepages = 0;
+ cc->nr_migratepages = 0;
+ cc->zone = zone;
+ INIT_LIST_HEAD(&cc->freepages);
+ INIT_LIST_HEAD(&cc->migratepages);
- compact_zone(zone, &cc);
+ if (cc->order < 0 || !compaction_deferred(zone))
+ compact_zone(zone, cc);
- VM_BUG_ON(!list_empty(&cc.freepages));
- VM_BUG_ON(!list_empty(&cc.migratepages));
+ VM_BUG_ON(!list_empty(&cc->freepages));
+ VM_BUG_ON(!list_empty(&cc->migratepages));
}
return 0;
}
+int compact_pgdat(pg_data_t *pgdat, int order)
+{
+ struct compact_control cc = {
+ .order = order,
+ .sync = false,
+ };
+
+ return __compact_pgdat(pgdat, &cc);
+}
+
+static int compact_node(int nid)
+{
+ pg_data_t *pgdat;
+ struct compact_control cc = {
+ .order = -1,
+ .sync = true,
+ };
+
+ if (nid < 0 || nid >= nr_node_ids || !node_online(nid))
+ return -EINVAL;
+ pgdat = NODE_DATA(nid);
+
+ return __compact_pgdat(pgdat, &cc);
+}
+
/* Compact all nodes in the system */
static int compact_nodes(void)
{