> On Dec 7, 2021, at 8:36 AM, Michal Hocko <mhocko@xxxxxxxx> wrote: > > On Tue 07-12-21 17:27:29, Michal Hocko wrote: > [...] >> So your proposal is to drop set_node_online from the patch and add it as >> a separate one which handles >> - sysfs part (i.e. do not register a node which doesn't span a >> physical address space) >> - hotplug side of (drop the pgd allocation, register node lazily >> when a first memblocks are registered) > > In other words, the first stage > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index c5952749ad40..f9024ba09c53 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -6382,7 +6382,11 @@ static void __build_all_zonelists(void *data) > if (self && !node_online(self->node_id)) { > build_zonelists(self); > } else { > - for_each_online_node(nid) { > + /* > + * All possible nodes have pgdat preallocated > + * free_area_init > + */ > + for_each_node(nid) { > pg_data_t *pgdat = NODE_DATA(nid); > > build_zonelists(pgdat); Will it blow up memory usage for the nodes which might never be onlined? I prefer the idea of init on demand. Even now there is an existing problem. In my experiments, I observed _huge_ memory consumption increase by increasing number of possible numa nodes. I’m going to report it in separate mail thread. Thanks, —-Alexey
Attachment:
signature.asc
Description: Message signed with OpenPGP