On 04/10/2017 01:03 PM, Michal Hocko wrote: > From: Michal Hocko <[email protected]> > > Memory hotplug (add_memory_resource) has to reinitialize node > infrastructure if the node is offline (one which went through the > complete add_memory(); remove_memory() cycle). That involves node > registration to the kobj infrastructure (register_node), the proper > association with cpus (register_cpu_under_node) and finally creation of > node<->memblock symlinks (link_mem_sections). > > The last part requires to know node_start_pfn and node_spanned_pages > which we currently have but a leter patch will postpone this > initialization to the onlining phase which happens later. In fact we do > not need to rely on the early pgdat initialization even now because the > currently hot added pfn range is currently known. > > Split register_one_node into core which does all the common work for > the boot time NUMA initialization and the hotplug (__register_one_node). > register_one_node keeps the full initialization while hotplug calls > __register_one_node and manually calls link_mem_sections for the proper > range. > > This shouldn't introduce any functional change. > > Signed-off-by: Michal Hocko <[email protected]>
Acked-by: Vlastimil Babka <[email protected]> nit: > @@ -1387,7 +1387,22 @@ int __ref add_memory_resource(int nid, struct resource > *res, bool online) > node_set_online(nid); > > if (new_node) { > - ret = register_one_node(nid); > + unsigned long start_pfn = start >> PAGE_SHIFT; > + unsigned long nr_pages = size >> PAGE_SHIFT; > + > + ret = __register_one_node(nid); > + if (ret) > + goto register_fail; > + > + /* > + * link memory sections under this node. This is already > + * done when creatig memory section in register_new_memory > + * but that depends to have the node registered so offline > + * nodes have to go through register_node. > + * TODO clean up this mess. Is this a work-in-progress or final TODO? :) > + */ > + ret = link_mem_sections(nid, start_pfn, nr_pages); > +register_fail: > /* > * If sysfs file of new node can't create, cpu on the node > * can't be hot-added. There is no rollback way now. >
