[PATCH 4/4] powerpc/numa: Set fallback nodes for offline nodes

[Bharata B Rao]

This patchset can also fix a related problem that I reported earlier at
https://lists.ozlabs.org/pipermail/linuxppc-dev/2020-March/206076.html
with an additional change, suggested by Srikar as shown below:

On Tue, Mar 17, 2020 at 06:47:53PM +0530, Srikar Dronamraju wrote:
> Currently fallback nodes for offline nodes aren't set. Hence by default
> node 0 ends up being the default node. However node 0 might be offline.
> 
> Fix this by explicitly setting fallback node. Ensure first_memory_node
> is set before kernel does explicit setting of fallback node.
> 
>  arch/powerpc/mm/numa.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
> index 281531340230..6e97ab6575cb 100644
> --- a/arch/powerpc/mm/numa.c
> +++ b/arch/powerpc/mm/numa.c
> @@ -827,7 +827,16 @@ void __init dump_numa_cpu_topology(void)
>  	if (!numa_enabled)
>  		return;
>  
> -	for_each_online_node(node) {
> +	for_each_node(node) {
> +		/*
> +		 * For all possible but not yet online nodes, ensure their
> +		 * node_numa_mem is set correctly so that kmalloc_node works
> +		 * for such nodes.
> +		 */
> +		if (!node_online(node)) {

Change the above line to like below:

+               if (!node_state(node, N_MEMORY)) {

Regards,
Bharata.