On 2016/7/23 4:11, Andrew Morton wrote: > On Fri, 22 Jul 2016 10:57:48 +0800 Xishi Qiu <qiuxishi@xxxxxxxxxx> wrote: > >> Memory offline could happen on both movable zone and non-movable zone. >> We can offline the whole node if the zone is movable zone, and if the >> zone is non-movable zone, we cannot offline the whole node, because >> some kernel memory can't be migrated. >> >> So if we offline a node with movable zone, use prefer mempolicy to alloc >> new page from the next node instead of the current node or other remote >> nodes, because re-migrate is a waste of time and the distance of the >> remote nodes is often very large. >> >> Also use GFP_HIGHUSER_MOVABLE to alloc new page if the zone is movable >> zone. > > This conflicts pretty significantly with your "mem-hotplug: use > different mempolicy in alloc_migrate_target()". Does it replace > "mem-hotplug: use different mempolicy in alloc_migrate_target()" and > your "mem-hotplug: use GFP_HIGHUSER_MOVABLE in, > alloc_migrate_target()", or what? > Hi Andrew, Yes, this patch is v2, "mem-hotplug: use different mempolicy in alloc_migrate_target()" and "mem-hotplug: use GFP_HIGHUSER_MOVABLE in alloc_migrate_target()" are v1, so just replace them. Joonsoo and Vlastimil point that migratable pages are not always from user space, so it is not correct to use GFP_HIGHUSER_MOVABLE in alloc_migrate_target(). David points that CMA and memory offline are distinct usecases and probably deserve their own callbacks. Thanks, Xishi Qiu > > . > -- 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>