At 11/01/2012 02:21 AM, David Rientjes Wrote: > On Wed, 31 Oct 2012, Wen Congyang wrote: > >> From: Lai Jiangshan <laijs@xxxxxxxxxxxxxx> >> >> is_valid_nodemask() is introduced by 19770b32. but it does not match >> its comments, because it does not check the zone which > policy_zone. >> >> Also in b377fd, this commits told us, if highest zone is ZONE_MOVABLE, >> we should also apply memory policies to it. so ZONE_MOVABLE should be valid zone >> for policies. is_valid_nodemask() need to be changed to match it. >> >> Fix: check all zones, even its zoneid > policy_zone. >> Use nodes_intersects() instead open code to check it. >> > > This changes the semantics of MPOL_BIND to be considerably different than > what it is today: slab allocations are no longer bound by such a policy > which isn't consistent with what userspace expects or is specified by > set_mempolicy() and there's no way, with your patch, to actually specify > that we don't care about ZONE_MOVABLE and that the slab allocations > _should_ actually be allocated on movable-only zones. You have to respect > cases where people aren't interested in node hotplug and not cause a > regression. > Should we allow the user to bind a task to a node which has only ZONE_MOVABLE memory? Thanks Wen Congyang -- 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>