mm/numa: Skip NUMA_NO_NODE and online nodes in numa_map_to_online_node()

Update numa_map_to_online_node() to stop falling back to numa node 0
when the input is NUMA_NO_NODE. Also, skip the lookup if @node is
online. This makes the routine compatible with other arch node mapping
routines.

Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/157401275716.43284.13185549705765009174.stgit@dwillia2-desk3.amr.corp.intel.com
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/158188325316.894464.15650888748083329531.stgit@dwillia2-desk3.amr.corp.intel.com

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 756d6e5..19f7e71 100644 (file)
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -135,21 +135,17 @@ static struct mempolicy preferred_node_policy[MAX_NUMNODES];
  */
 int numa_map_to_online_node(int node)
 {
-       int min_node;
+       int min_dist = INT_MAX, dist, n, min_node;
 
-       if (node == NUMA_NO_NODE)
-               node = 0;
+       if (node == NUMA_NO_NODE || node_online(node))
+               return node;
 
        min_node = node;
-       if (!node_online(node)) {
-               int min_dist = INT_MAX, dist, n;
-
-               for_each_online_node(n) {
-                       dist = node_distance(node, n);
-                       if (dist < min_dist) {
-                               min_dist = dist;
-                               min_node = n;
-                       }
+       for_each_online_node(n) {
+               dist = node_distance(node, n);
+               if (dist < min_dist) {
+                       min_dist = dist;
+                       min_node = n;
                }
        }