On Thu, Aug 15, 2013 at 02:42:09PM +0100, Mel Gorman wrote: > On Thu, Aug 15, 2013 at 10:19:35PM +0900, Minchan Kim wrote: > > > > > > Why? We're looking for pages to migrate. If the page is free and at the > > > maximum order then there is no point searching in the middle of a free > > > page. > > > > isolate_migratepages_range API works with [low_pfn, end_pfn) > > and we can't guarantee page_order in normal compaction path > > so I'd like to limit the skipping by end_pfn conservatively. > > > > Fine > > s/MAX_ORDER_NR_PAGES/pageblock_nr_pages/ > > and take the min of it and > > low_pfn = min(low_pfn, end_pfn - 1) True. That was really what I suggested to Xishi. Only thing we need it is just number to justify for proving the benefit. Thanks. -- Kind regards, Minchan Kim -- 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>