On Fri, 11 Nov 2011 16:21:19 +0000 Mel Gorman <mgorman@xxxxxxx> wrote: > When min_free_kbytes is updated, some pageblocks are marked MIGRATE_RESERVE. > Ordinarily, this work is unnoticable as it happens early in boot but on > large machines with 1TB of memory, this has been reported to delay > boot times, probably due to the NUMA distances involved. > > The bulk of the work is due to calling calling pageblock_is_reserved() > an unnecessary amount of times and accessing far more struct page > metadata than is necessary. This patch significantly reduces the > amount of work done by setup_zone_migrate_reserve() improving boot > times on 1TB machines. > By how much? :) (I mainly ask because I'm curious to know how long the kernel takes to boot on a 1TB machine...) -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>