On Thu, 2017-06-01 at 16:33 -0500, Reza Arbab wrote:
> On Thu, Jun 01, 2017 at 07:36:31PM +1000, Michael Ellerman wrote:
> > I don't think that's what the patch does. It just marks 32 (!?) nodes
> > as online. Or if you're talking about reverting 3af229f2071f that
> > leaves you with 256 possible nodes. Both of which are wasteful.
>
> To be clear, with Balbir's set the latter is no longer wasteful.
>
> > The right fix is to make sure any nodes which are present at boot
> > remain in the possible map, even if they don't have memory/CPUs
> > assigned at boot.
>
> I'm still hoping 3af229f2071f could indeed be reverted some day, but
> until then the following would follow your suggestion for our GPU nodes.
> What do you think?
>
> --- a/arch/powerpc/mm/numa.c
> +++ b/arch/powerpc/mm/numa.c
> @@ -895,6 +895,7 @@ static void __init setup_node_data(int nid, u64
> start_pfn, u64 end_pfn)
> void __init initmem_init(void)
> {
> int nid, cpu;
> + struct device_node *dn;
>
> max_low_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
> max_pfn = max_low_pfn;
> @@ -911,6 +912,18 @@ void __init initmem_init(void)
> */
> nodes_and(node_possible_map, node_possible_map, node_online_map);
>
> + /*
> + * Consider an ibm,coherent-device-memory node possible. Even though
> + * it is not online at boot, it may be hotplugged later.
> + */
> + for_each_compatible_node(dn, NULL, "ibm,coherent-device-memory") {
> + nid = of_node_to_nid_single(dn);
> + if (nid < 0)
> + continue;
> +
> + node_set(nid, node_possible_map);
> + }
> +
I think it looks reasonable, although I'd really like to set a limit
in firmware on the number of nodes and fix memcg hotplug correctly in
the medium term.
Balbir Singh.
> for_each_online_node(nid) {
> unsigned long start_pfn, end_pfn;
>
>
