On Fri, Feb 10, 2017 at 06:23:35PM +0100, Vlastimil Babka wrote: > When detecting whether compaction has succeeded in forming a high-order page, > __compact_finished() employs a watermark check, followed by an own search for > a suitable page in the freelists. This is not ideal for two reasons: > > - The watermark check also searches high-order freelists, but has a less strict > criteria wrt fallback. It's therefore redundant and waste of cycles. This was > different in the past when high-order watermark check attempted to apply > reserves to high-order pages. > > - The watermark check might actually fail due to lack of order-0 pages. > Compaction can't help with that, so there's no point in continuing because of > that. It's possible that high-order page still exists and it terminates. > > This patch therefore removes the watermark check. This should save some cycles > and terminate compaction sooner in some cases. > > Signed-off-by: Vlastimil Babka <vbabka@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>
