On Sun 11-06-17 09:45:35, Wei Yang wrote: > On Thu, Jun 08, 2017 at 02:23:18PM +0200, Michal Hocko wrote: > >From: Michal Hocko <mhocko@xxxxxxxx> > > > >movable_node kernel parameter allows to make hotplugable NUMA > >nodes to put all the hotplugable memory into movable zone which > >allows more or less reliable memory hotremove. At least this > >is the case for the NUMA nodes present during the boot (see > >find_zone_movable_pfns_for_nodes). > > > >This is not the case for the memory hotplug, though. > > > > echo online > /sys/devices/system/memory/memoryXYZ/status > > > >will default to a kernel zone (usually ZONE_NORMAL) unless the > >particular memblock is already in the movable zone range which is not > >the case normally when onlining the memory from the udev rule context > >for a freshly hotadded NUMA node. The only option currently is to have a > >special udev rule to echo online_movable to all memblocks belonging to > >such a node which is rather clumsy. Not the mention this is inconsistent > >as well because what ended up in the movable zone during the boot will > >end up in a kernel zone after hotremove & hotadd without special care. > > > > A kernel zone here means? Which is the counterpart in zone_type? or a > combination of several zone_type? Any zone but < ZONE_HIGHMEM. The specific zone depends on the placement. But it is ZONE_NORMAL in most situations. -- Michal Hocko SUSE Labs -- 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>
