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authorAndrea Arcangeli <aarcange@redhat.com>2011-01-13 15:47:11 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-13 17:32:46 -0800
commit5a03b051ed87e72b959f32a86054e1142ac4cf55 (patch)
tree31f0e8efb86d48b0292f8a7ea4bd9cf7c930a0ab /mm/vmscan.c
parent878aee7d6b5504e01b9caffce080e792b6b8d090 (diff)
thp: use compaction in kswapd for GFP_ATOMIC order > 0
This takes advantage of memory compaction to properly generate pages of order > 0 if regular page reclaim fails and priority level becomes more severe and we don't reach the proper watermarks. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/vmscan.c')
-rw-r--r--mm/vmscan.c30
1 files changed, 20 insertions, 10 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c
index cfdef0bcc7a..f5b762ae23a 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -41,6 +41,7 @@
#include <linux/memcontrol.h>
#include <linux/delayacct.h>
#include <linux/sysctl.h>
+#include <linux/compaction.h>
#include <asm/tlbflush.h>
#include <asm/div64.h>
@@ -2382,6 +2383,7 @@ loop_again:
* cause too much scanning of the lower zones.
*/
for (i = 0; i <= end_zone; i++) {
+ int compaction;
struct zone *zone = pgdat->node_zones + i;
int nr_slab;
@@ -2411,9 +2413,26 @@ loop_again:
lru_pages);
sc.nr_reclaimed += reclaim_state->reclaimed_slab;
total_scanned += sc.nr_scanned;
+
+ compaction = 0;
+ if (order &&
+ zone_watermark_ok(zone, 0,
+ high_wmark_pages(zone),
+ end_zone, 0) &&
+ !zone_watermark_ok(zone, order,
+ high_wmark_pages(zone),
+ end_zone, 0)) {
+ compact_zone_order(zone,
+ order,
+ sc.gfp_mask, false,
+ COMPACT_MODE_KSWAPD);
+ compaction = 1;
+ }
+
if (zone->all_unreclaimable)
continue;
- if (nr_slab == 0 && !zone_reclaimable(zone))
+ if (!compaction && nr_slab == 0 &&
+ !zone_reclaimable(zone))
zone->all_unreclaimable = 1;
/*
* If we've done a decent amount of scanning and
@@ -2424,15 +2443,6 @@ loop_again:
total_scanned > sc.nr_reclaimed + sc.nr_reclaimed / 2)
sc.may_writepage = 1;
- /*
- * Compact the zone for higher orders to reduce
- * latencies for higher-order allocations that
- * would ordinarily call try_to_compact_pages()
- */
- if (sc.order > PAGE_ALLOC_COSTLY_ORDER)
- compact_zone_order(zone, sc.order, sc.gfp_mask,
- false);
-
if (!zone_watermark_ok_safe(zone, order,
high_wmark_pages(zone), end_zone, 0)) {
all_zones_ok = 0;