On Fri, Dec 7, 2018 at 11:56 PM Michal Hocko <mhocko@xxxxxxxxxx> wrote: > > On Fri 07-12-18 22:27:13, Pingfan Liu wrote: > [...] > > diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c > > index 1308f54..4dc497d 100644 > > --- a/arch/x86/mm/numa.c > > +++ b/arch/x86/mm/numa.c > > @@ -754,18 +754,23 @@ void __init init_cpu_to_node(void) > > { > > int cpu; > > u16 *cpu_to_apicid = early_per_cpu_ptr(x86_cpu_to_apicid); > > + int node, nr; > > > > BUG_ON(cpu_to_apicid == NULL); > > + nr = cpumask_weight(cpu_possible_mask); > > + > > + /* bring up all possible node, since dev->numa_node */ > > + //should check acpi works for node possible, > > + for_each_node(node) > > + if (!node_online(node)) > > + init_memory_less_node(node); > > I suspect there is no change if you replace for_each_node by > for_each_node_mask(nid, node_possible_map) > > here. If that is the case then we are probably calling > free_area_init_node too early. I do not see it yet though. Maybe I do not clearly get your meaning, just try to guess. But if you worry about node_possible_map, then it is dynamically set by alloc_node_data(). The map is changed after the first time to call free_area_init_node() for the node with memory. This logic is the same as the current x86 code. Thanks, Pingfan