From 1b2ffb7896ad46067f5b9ebf7de1891d74a4cdef Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Wed, 1 Feb 2006 03:05:34 -0800 Subject: [PATCH] Zone reclaim: Allow modification of zone reclaim behavior In some situations one may want zone_reclaim to behave differently. For example a process writing large amounts of memory will spew unto other nodes to cache the writes if many pages in a zone become dirty. This may impact the performance of processes running on other nodes. Allowing writes during reclaim puts a stop to that behavior and throttles the process by restricting the pages to the local zone. Similarly one may want to contain processes to local memory by enabling regular swap behavior during zone_reclaim. Off node memory allocation can then be controlled through memory policies and cpusets. Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmscan.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'mm/vmscan.c') diff --git a/mm/vmscan.c b/mm/vmscan.c index 8760a4abfa1f..9e2ef3624d77 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1592,6 +1592,11 @@ module_init(kswapd_init) */ int zone_reclaim_mode __read_mostly; +#define RECLAIM_OFF 0 +#define RECLAIM_ZONE (1<<0) /* Run shrink_cache on the zone */ +#define RECLAIM_WRITE (1<<1) /* Writeout pages during reclaim */ +#define RECLAIM_SWAP (1<<2) /* Swap pages out during reclaim */ + /* * Mininum time between zone reclaim scans */ @@ -1630,8 +1635,8 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) if (!cpus_empty(mask) && node_id != numa_node_id()) return 0; - sc.may_writepage = 0; - sc.may_swap = 0; + sc.may_writepage = !!(zone_reclaim_mode & RECLAIM_WRITE); + sc.may_swap = !!(zone_reclaim_mode & RECLAIM_SWAP); sc.nr_scanned = 0; sc.nr_reclaimed = 0; sc.priority = ZONE_RECLAIM_PRIORITY + 1; -- cgit v1.2.3-55-g7522