mm: vmscan: kswapd should not free an excessive number of pages when balancing small...

[linux-flexiantxendom0-natty.git] / include / linux / swap.h

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 97a5514..3b454c0 100644 (file)
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -155,6 +155,15 @@ enum {
 #define SWAP_CLUSTER_MAX 32
 #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
+ * spend not more than 1% of the memory for this zone balancing "gap".
+ */
+#define KSWAPD_ZONE_BALANCE_GAP_RATIO 100
+
 #define SWAP_MAP_MAX   0x3e    /* Max duplication count, in first swap_map */
 #define SWAP_MAP_BAD   0x3f    /* Note pageblock is bad, in first swap_map */
 #define SWAP_HAS_CACHE 0x40    /* Flag page is cached, in first swap_map */