On 01/16/2013 02:01 PM, KOSAKI Motohiro wrote: >>>> >>>> Things I'm wondering: >>>> >>>> - is there *really* a case for retaining the boot option if/when >>>> SRAT support is available? >>> >>> Yes. If SRAT support is available, all memory which enabled hotpluggable >>> bit are managed by ZONEMOVABLE. But performance degradation may >>> occur by NUMA because we can only allocate anonymous page and page-cache >>> from these memory. >>> >>> In this case, if user cannot change SRAT information, user needs a way to >>> select/set removable memory manually. >> >> If I understand this correctly you mean that once SRAT parsing is >> implemented, the user can use movablecore_map to override that SRAT >> parsing, yes? That movablecore_map will take precedence over SRAT? > > I think movablecore_map (I prefer movablemem than it, btw) should behave so. > because of, for past three years, almost all memory hotplug bug was handled > only I and kamezawa-san and, afaik, both don't have hotremove aware specific > hardware. > > So, if the new feature require specific hardware, we can't maintain this area > any more. > It is more so than that: the design principle should always be that lower-level directives, if present, take precedence over higher-level directives. The reason for that should be pretty obvious: one of the main uses of the low-level directives is to override the high-level directives due to bugs or debugging needs. -hpa -- 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>