On Thu 15-06-17 11:13:54, Wei Yang wrote: > On Mon, Jun 12, 2017 at 08:45:02AM +0200, Michal Hocko wrote: > >On Mon 12-06-17 12:28:32, 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). > >> > > >> > >> When movable_node is enabled, we would have overlapped zones, right? > > > >It won't based on this patch. See movable_pfn_range > > > > Ok, I went through the code and here maybe a question not that close related > to this patch. Please start a new thread with unrelated questions > I did some experiment with qemu+kvm and see this. > > Guest config: 8G RAM, 2 nodes with 4G on each > Guest kernel: 4.11 > Guest kernel command: kernelcore=1G > > The log message in kernel is: > > [ 0.000000] Zone ranges: > [ 0.000000] DMA [mem 0x0000000000001000-0x0000000000ffffff] > [ 0.000000] DMA32 [mem 0x0000000001000000-0x00000000ffffffff] > [ 0.000000] Normal [mem 0x0000000100000000-0x000000023fffffff] > [ 0.000000] Movable zone start for each node > [ 0.000000] Node 0: 0x0000000100000000 > [ 0.000000] Node 1: 0x0000000140000000 > > We see on node 2, ZONE_NORMAL overlap with ZONE_MOVABLE. > [0x0000000140000000 - 0x000000023fffffff] belongs to both ZONE. Not really. The above output is just confusing a bit. Zone ranges print arch_zone_{lowest,highest}_possible_pfn range while the Movable zone is excluded from that in adjust_zone_range_for_zone_movable -- 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>