On Thu, May 01, 2014 at 02:35:42PM -0700, David Rientjes wrote: > Memory compaction works by having a "freeing scanner" scan from one end of a > zone which isolates pages as migration targets while another "migrating scanner" > scans from the other end of the same zone which isolates pages for migration. > > When page migration fails for an isolated page, the target page is returned to > the system rather than the freelist built by the freeing scanner. This may > require the freeing scanner to continue scanning memory after suitable migration > targets have already been returned to the system needlessly. > > This patch returns destination pages to the freeing scanner freelist when page > migration fails. This prevents unnecessary work done by the freeing scanner but > also encourages memory to be as compacted as possible at the end of the zone. > > Reported-by: Greg Thelen <gthelen@xxxxxxxxxx> > Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx> Acked-by: Mel Gorman <mgorman@xxxxxxx> -- Mel Gorman SUSE Labs -- 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>