On Thu, Apr 11, 2013 at 08:57:51PM +0100, Mel Gorman wrote: > kswapd stops raising the scanning priority when at least SWAP_CLUSTER_MAX > pages have been reclaimed or the pgdat is considered balanced. It then > rechecks if it needs to restart at DEF_PRIORITY and whether high-order > reclaim needs to be reset. This is not wrong per-se but it is confusing > to follow and forcing kswapd to stay at DEF_PRIORITY may require several > restarts before it has scanned enough pages to meet the high watermark even > at 100% efficiency. This patch irons out the logic a bit by controlling > when priority is raised and removing the "goto loop_again". > > This patch has kswapd raise the scanning priority until it is scanning > enough pages that it could meet the high watermark in one shrink of the > LRU lists if it is able to reclaim at 100% efficiency. It will not raise > the scanning prioirty higher unless it is failing to reclaim any pages. > > To avoid infinite looping for high-order allocation requests kswapd will > not reclaim for high-order allocations when it has reclaimed at least > twice the number of pages as the allocation request. > > Signed-off-by: Mel Gorman <mgorman@xxxxxxx> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>