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

[Srikar Dronamraju]

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.

Cc: Andrew Morton <akpm at linux-foundation.org>
Cc: linux-mm at kvack.org
Cc: Mel Gorman <mgorman at suse.de>
Cc: Michael Ellerman <mpe at ellerman.id.au>
Cc: Sachin Sant <sachinp at linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko at kernel.org>
Cc: Christopher Lameter <cl at linux.com>
Cc: linuxppc-dev at lists.ozlabs.org
Cc: Joonsoo Kim <iamjoonsoo.kim at lge.com>
Cc: Kirill Tkhai <ktkhai at virtuozzo.com>
Cc: Vlastimil Babka <vbabka at suse.cz>
Cc: Srikar Dronamraju <srikar at linux.vnet.ibm.com>
Cc: Bharata B Rao <bharata at linux.ibm.com>

Reported-by: Sachin Sant <sachinp at linux.vnet.ibm.com>
Tested-by: Sachin Sant <sachinp at linux.vnet.ibm.com>
Signed-off-by: Srikar Dronamraju <srikar at linux.vnet.ibm.com>
---
 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)) {
+			reset_numa_mem(node);
+			continue;
+		}
 		pr_info("Node %d CPUs:", node);
 
 		count = 0;
-- 
2.18.1