On Mon 13-12-21 16:07:18, David Hildenbrand wrote: > On 13.12.21 16:06, Michal Hocko wrote: > > On Thu 09-12-21 11:48:42, Michal Hocko wrote: > > [...] > >> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > >> index 852041f6be41..2d38a431f62f 100644 > >> --- a/mm/memory_hotplug.c > >> +++ b/mm/memory_hotplug.c > >> @@ -1161,19 +1161,21 @@ static void reset_node_present_pages(pg_data_t *pgdat) > >> } > >> > >> /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ > >> -static pg_data_t __ref *hotadd_new_pgdat(int nid) > >> +static pg_data_t __ref *hotadd_init_pgdat(int nid) > >> { > >> struct pglist_data *pgdat; > >> > >> pgdat = NODE_DATA(nid); > >> - if (!pgdat) { > >> - pgdat = arch_alloc_nodedata(nid); > >> - if (!pgdat) > >> - return NULL; > >> > >> + /* > >> + * NODE_DATA is preallocated (free_area_init) but its internal > >> + * state is not allocated completely. Add missing pieces. > >> + * Completely offline nodes stay around and they just need > >> + * reintialization. > >> + */ > >> + if (!pgdat->per_cpu_nodestats) { > >> pgdat->per_cpu_nodestats = > >> alloc_percpu(struct per_cpu_nodestat); > >> - arch_refresh_nodedata(nid, pgdat); > > > > This should really be > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > > index 42211485bcf3..2daa88ce8c80 100644 > > --- a/mm/memory_hotplug.c > > +++ b/mm/memory_hotplug.c > > @@ -1173,7 +1173,7 @@ static pg_data_t __ref *hotadd_init_pgdat(int nid) > > * Completely offline nodes stay around and they just need > > * reintialization. > > */ > > - if (!pgdat->per_cpu_nodestats) { > > + if (pgdat->per_cpu_nodestats == &boot_nodestats) { > > pgdat->per_cpu_nodestats = > > alloc_percpu(struct per_cpu_nodestat); > > } else { > > > > I'll try giving this some churn later this week -- busy with other stuff. Please hang on, this needs to be done yet slightly differently. I will post something more resembling a final patch later today. For the purpose of the testing this should be sufficient for now. -- Michal Hocko SUSE Labs