Srikar Dronamraju <sri...@linux.vnet.ibm.com> writes: > * Nathan Lynch <nath...@linux.ibm.com> [2021-04-07 07:19:10]: > >> Sorry for the delay in following up here. >> > > No issues. > >> >> So I'd suggest that pseries_add_processor() be made to update >> >> these things when the CPUs are marked present, before onlining them. >> > >> > In pseries_add_processor, we are only marking the cpu as present. i.e >> > I believe numa_setup_cpu() would not have been called. So we may not have a >> > way to associate the CPU to the node. Otherwise we will have to call >> > numa_setup_cpu() or the hcall_vphn. >> > >> > We could try calling numa_setup_cpu() immediately after we set the >> > CPU to be present, but that would be one more extra hcall + I dont know if >> > there are any more steps needed before CPU being made present and >> > associating the CPU to the node. >> >> An additional hcall in this path doesn't seem too expensive. >> >> > Are we sure the node is already online? >> >> I see that dlpar_online_cpu() calls find_and_online_cpu_nid(), so yes I >> think that's covered. > > Okay, > > Can we just call set_cpu_numa_node() at the end of map_cpu_to_node(). > The advantage would be the update to numa_cpu_lookup_table and cpu_to_node > would happen at the same time and would be in sync.
I don't know. I guess this question just makes me wonder whether powerpc needs to have the additional lookup table. How is it different from the generic per_cpu numa_node?
