From 2a11ff06d7d12be5d1bbcf592fff649b45ac2388 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Wed, 1 Feb 2006 03:05:33 -0800 Subject: [PATCH] zone_reclaim: configurable off node allocation period. Currently the zone_reclaim code has a fixed window of 30 seconds of off node allocations should a local zone have no unused pagecache pages left. Reclaim will be attempted again after this timeout period to avoid repeated useless scans for memory. This is also useful to established sufficiently large off node allocation chunks to relieve the local node. It may be beneficial to adjust that time period for some special situations. For example if memory use was exceeding node capacity one may want to give up for longer periods of time. If memory spikes intermittendly then one may want to shorten the time period to reduce the number of off node allocations. This patch allows just that.... Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/sysctl/vm.txt | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'Documentation') diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index 391dd64363e75b..44518c02394901 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -28,6 +28,7 @@ Currently, these files are in /proc/sys/vm: - block_dump - drop-caches - zone_reclaim_mode +- zone_reclaim_interval ============================================================== @@ -137,4 +138,15 @@ of memory should be used for caching files from disk. It may be beneficial to switch this on if one wants to do zone reclaim regardless of the numa distances in the system. +================================================================ + +zone_reclaim_interval: + +The time allowed for off node allocations after zone reclaim +has failed to reclaim enough pages to allow a local allocation. + +Time is set in seconds and set by default to 30 seconds. + +Reduce the interval if undesired off node allocations occur. However, too +frequent scans will have a negative impact onoff node allocation performance. -- cgit 1.2.3-korg