summaryrefslogtreecommitdiffstats
path: root/include/linux/swap.h
diff options
context:
space:
mode:
authorJianyu Zhan <nasa4836@gmail.com>2014-06-04 16:10:38 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-06-04 16:54:11 -0700
commit4be89a34609659042ef0bf883ad76388fb5251bb (patch)
tree7a438185cb78e2c6d3aec1e64960e64188cb4afe /include/linux/swap.h
parentb7596fb43aa786fb3ee5015a73034fbb9e80feaa (diff)
downloadop-kernel-dev-4be89a34609659042ef0bf883ad76388fb5251bb.zip
op-kernel-dev-4be89a34609659042ef0bf883ad76388fb5251bb.tar.gz
mm/vmscan.c: use DIV_ROUND_UP for calculation of zone's balance_gap and correct comments.
Currently, we use (zone->managed_pages + KSWAPD_ZONE_BALANCE_GAP_RATIO-1) / KSWAPD_ZONE_BALANCE_GAP_RATIO to avoid a zero gap value. It's better to use DIV_ROUND_UP macro for neater code and clear meaning. Besides, the gap value is calculated against the per-zone "managed pages", not "present pages". This patch also corrects the comment and do some rephrasing. Signed-off-by: Jianyu Zhan <nasa4836@gmail.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Rafael Aquini <aquini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/swap.h')
-rw-r--r--include/linux/swap.h8
1 files changed, 4 insertions, 4 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 4348d95..4bdbee8 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -166,10 +166,10 @@ enum {
#define COMPACT_CLUSTER_MAX SWAP_CLUSTER_MAX
/*
- * Ratio between the present memory in the zone and the "gap" that
- * we're allowing kswapd to shrink in addition to the per-zone high
- * wmark, even for zones that already have the high wmark satisfied,
- * in order to provide better per-zone lru behavior. We are ok to
+ * Ratio between zone->managed_pages and the "gap" that above the per-zone
+ * "high_wmark". While balancing nodes, We allow kswapd to shrink zones that
+ * do not meet the (high_wmark + gap) watermark, even which already met the
+ * high_wmark, in order to provide better per-zone lru behavior. We are ok to
* spend not more than 1% of the memory for this zone balancing "gap".
*/
#define KSWAPD_ZONE_BALANCE_GAP_RATIO 100
OpenPOWER on IntegriCloud