I am running into this problem on PowerPC systems where Balbir's patch set was targeted. So, yes, I do need to be able to add/enable a new numa node during system execution in cases where more resources (memory, virtual processors) are added to the system dynamically.
On 05/25/2017 10:46 PM, Michael Ellerman wrote: > Reza Arbab <ar...@linux.vnet.ibm.com> writes: > >> On Thu, May 25, 2017 at 04:19:53PM +1000, Michael Ellerman wrote: >>> The commit message for 3af229f2071f says: >>> >>> In practice, we never see a system with 256 NUMA nodes, and in fact, we >>> do not support node hotplug on power in the first place, so the nodes >>> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >>> that are online when we come up are the nodes that will be present for >>> the lifetime of this kernel. >>> >>> Is that no longer true? >> >> I don't know what the reasoning behind that statement was at the time, >> but as far as I can tell, the only thing missing for node hotplug now is >> Balbir's patchset [1]. He fixes the resource issue which motivated >> 3af229f2071f and reverts it. >> >> With that set, I can instantiate a new numa node just by doing >> add_memory(nid, ...) where nid doesn't currently exist. > > But does that actually happen on any real system? > > cheers > > -- Michael W. Bringmann Linux Technology Center IBM Corporation Tie-Line 363-5196 External: (512) 286-5196 Cell: (512) 466-0650 m...@linux.vnet.ibm.com