[PATCH 1/2] openvswitch: fix flow stats accounting when node 0 is not possible

[Thadeu Lima de Souza Cascardo]

On a system with only node 1 as possible, all statistics is going to be
accounted on node 0 as it will have a single writer.

However, when getting and clearing the statistics, node 0 is not going
to be considered, as it's not a possible node.

Tested that statistics are not zero on a system with only node 1
possible. Also compile-tested with CONFIG_NUMA off.

Signed-off-by: Thadeu Lima de Souza Cascardo <casca...@redhat.com>
---

I am providing this intermediate patch, that will be thrown out by the next one,
in case there is any need to backport this fix.

---
 net/openvswitch/flow.c       | 6 ++++--
 net/openvswitch/flow_table.c | 5 +++--
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c
index 0ea128e..3609f37 100644
--- a/net/openvswitch/flow.c
+++ b/net/openvswitch/flow.c
@@ -142,7 +142,8 @@ void ovs_flow_stats_get(const struct sw_flow *flow,
        *tcp_flags = 0;
        memset(ovs_stats, 0, sizeof(*ovs_stats));
 
-       for_each_node(node) {
+       /* We open code this to make sure node 0 is always considered */
+       for (node = 0; node < MAX_NUMNODES; node = next_node(node, 
node_possible_map)) {
                struct flow_stats *stats = 
rcu_dereference_ovsl(flow->stats[node]);
 
                if (stats) {
@@ -165,7 +166,8 @@ void ovs_flow_stats_clear(struct sw_flow *flow)
 {
        int node;
 
-       for_each_node(node) {
+       /* We open code this to make sure node 0 is always considered */
+       for (node = 0; node < MAX_NUMNODES; node = next_node(node, 
node_possible_map)) {
                struct flow_stats *stats = ovsl_dereference(flow->stats[node]);
 
                if (stats) {
diff --git a/net/openvswitch/flow_table.c b/net/openvswitch/flow_table.c
index d073fff..957a3c3 100644
--- a/net/openvswitch/flow_table.c
+++ b/net/openvswitch/flow_table.c
@@ -148,8 +148,9 @@ static void flow_free(struct sw_flow *flow)
                kfree(flow->id.unmasked_key);
        if (flow->sf_acts)
                ovs_nla_free_flow_actions((struct sw_flow_actions __force 
*)flow->sf_acts);
-       for_each_node(node)
-               if (flow->stats[node])
+       /* We open code this to make sure node 0 is always considered */
+       for (node = 0; node < MAX_NUMNODES; node = next_node(node, 
node_possible_map))
+               if (node != 0 && flow->stats[node])
                        kmem_cache_free(flow_stats_cache,
                                        (struct flow_stats __force 
*)flow->stats[node]);
        kmem_cache_free(flow_cache, flow);
-- 
2.7.4