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| author | Minchan Kim <minchan.kim@gmail.com> | 2010-03-05 13:41:45 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-03-06 11:26:24 -0800 |
| commit | 45973d74fd3b1e3e16c025b688a725c7653b1443 (patch) | |
| tree | 79b002bf8da8807a4d82314426611ca2109f83e8 /mm/vmscan.c | |
| parent | 59e99e5b9706867f18d4a36c1e4645fbaacbec2e (diff) | |
| download | lwn-45973d74fd3b1e3e16c025b688a725c7653b1443.tar.gz lwn-45973d74fd3b1e3e16c025b688a725c7653b1443.zip | |
vmscan: check high watermark after shrink zone
Kswapd checks that zone has sufficient pages free via zone_watermark_ok().
If any zone doesn't have enough pages, we set all_zones_ok to zero.
!all_zone_ok makes kswapd retry rather than sleeping.
I think the watermark check before shrink_zone() is pointless. Only after
kswapd has tried to shrink the zone is the check meaningful.
Move the check to after the call to shrink_zone().
[akpm@linux-foundation.org: fix comment, layout]
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.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.c | 22 |
1 files changed, 12 insertions, 10 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index c26986c85ce0..96ebe6608d5c 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2060,9 +2060,6 @@ loop_again: priority != DEF_PRIORITY) continue; - if (!zone_watermark_ok(zone, order, - high_wmark_pages(zone), end_zone, 0)) - all_zones_ok = 0; temp_priority[i] = priority; sc.nr_scanned = 0; note_zone_scanning_priority(zone, priority); @@ -2102,13 +2099,18 @@ loop_again: total_scanned > sc.nr_reclaimed + sc.nr_reclaimed / 2) sc.may_writepage = 1; - /* - * We are still under min water mark. it mean we have - * GFP_ATOMIC allocation failure risk. Hurry up! - */ - if (!zone_watermark_ok(zone, order, min_wmark_pages(zone), - end_zone, 0)) - has_under_min_watermark_zone = 1; + if (!zone_watermark_ok(zone, order, + high_wmark_pages(zone), end_zone, 0)) { + all_zones_ok = 0; + /* + * We are still under min water mark. This + * means that we have a GFP_ATOMIC allocation + * failure risk. Hurry up! + */ + if (!zone_watermark_ok(zone, order, + min_wmark_pages(zone), end_zone, 0)) + has_under_min_watermark_zone = 1; + } } if (all_zones_ok) |