On Tue 01-02-22 02:41:19, Wei Yang wrote: > On Thu, Jan 27, 2022 at 03:47:40PM +0100, Michal Hocko wrote: > >[...] > >> > + > >> > + /* Allocator not initialized yet */ > >> > + pgdat = arch_alloc_nodedata(nid); > >> > + if (!pgdat) { > >> > + pr_err("Cannot allocate %zuB for node %d.\n", > >> > + sizeof(*pgdat), nid); > >> > + continue; > >> > + } > >> > + arch_refresh_nodedata(nid, pgdat); > >> > + free_area_init_memoryless_node(nid); > > free_area_init_memoryless_node() seems to be defined used out side > page_alloc.c? It just call free_area_init_node() directly. We want to use the > name to reflect the effect? yes. > >> > + /* > >> > + * not marking this node online because we do not want to > >> > + * confuse userspace by sysfs files/directories for node > >> > + * without any memory attached to it (see topology_init) > >> > + * The pgdat will get fully initialized when a memory is > >> > + * hotpluged into it by hotadd_init_pgdat > >> > + */ > > Hmm... which following step would mark the node online? On x86, the node is > onlined in alloc_node_date(). This is not onlined here. The comment tries to explain that this happens during the memory hotplug. Or maybe I have missed your question? [...] -- Michal Hocko SUSE Labs