openvswitch: collect mega flow mask stats

Collect mega flow mask stats. ovs-dpctl show command can be used to
display them for debugging and performance tuning.

Signed-off-by: Andy Zhou <azhou@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>

4 files changed, 53 insertions, 9 deletions

diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index cf270973095d..5bc5a4e64758 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -221,6 +221,7 @@ void ovs_dp_process_received_packet(struct vport *p, struct sk_buff *skb)
         struct dp_stats_percpu *stats;
         struct sw_flow_key key;
         u64 *stats_counter;
+        u32 n_mask_hit;
         int error;
 
         stats = this_cpu_ptr(dp->stats_percpu);
@@ -233,7 +234,7 @@ void ovs_dp_process_received_packet(struct vport *p, struct sk_buff *skb)
         }
 
         /* Look up flow. */
-        flow = ovs_flow_tbl_lookup(&dp->table, &key);
+        flow = ovs_flow_tbl_lookup(&dp->table, &key, &n_mask_hit);
         if (unlikely(!flow)) {
                 struct dp_upcall_info upcall;
 
@@ -258,6 +259,7 @@ out:
         /* Update datapath statistics. */
         u64_stats_update_begin(&stats->sync);
         (*stats_counter)++;
+        stats->n_mask_hit += n_mask_hit;
         u64_stats_update_end(&stats->sync);
 }
 
@@ -563,13 +565,18 @@ static struct genl_ops dp_packet_genl_ops[] = {
         }
 };
 
-static void get_dp_stats(struct datapath *dp, struct ovs_dp_stats *stats)
+static void get_dp_stats(struct datapath *dp, struct ovs_dp_stats *stats,
+                         struct ovs_dp_megaflow_stats *mega_stats)
 {
         int i;
 
+        memset(mega_stats, 0, sizeof(*mega_stats));
+
         stats->n_flows = ovs_flow_tbl_count(&dp->table);
+        mega_stats->n_masks = ovs_flow_tbl_num_masks(&dp->table);
 
         stats->n_hit = stats->n_missed = stats->n_lost = 0;
+
         for_each_possible_cpu(i) {
                 const struct dp_stats_percpu *percpu_stats;
                 struct dp_stats_percpu local_stats;
@@ -585,6 +592,7 @@ static void get_dp_stats(struct datapath *dp, struct ovs_dp_stats *stats)
                 stats->n_hit += local_stats.n_hit;
                 stats->n_missed += local_stats.n_missed;
                 stats->n_lost += local_stats.n_lost;
+                mega_stats->n_mask_hit += local_stats.n_mask_hit;
         }
 }
 
@@ -743,6 +751,14 @@ static struct sk_buff *ovs_flow_cmd_build_info(struct sw_flow *flow,
         return skb;
 }
 
+static struct sw_flow *__ovs_flow_tbl_lookup(struct flow_table *tbl,
+                                              const struct sw_flow_key *key)
+{
+        u32 __always_unused n_mask_hit;
+
+        return ovs_flow_tbl_lookup(tbl, key, &n_mask_hit);
+}
+
 static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
 {
         struct nlattr **a = info->attrs;
@@ -793,7 +809,7 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
                 goto err_unlock_ovs;
 
         /* Check if this is a duplicate flow */
-        flow = ovs_flow_tbl_lookup(&dp->table, &key);
+        flow = __ovs_flow_tbl_lookup(&dp->table, &key);
         if (!flow) {
                 /* Bail out if we're not allowed to create a new flow. */
                 error = -ENOENT;
@@ -905,7 +921,7 @@ static int ovs_flow_cmd_get(struct sk_buff *skb, struct genl_info *info)
                 goto unlock;
         }
 
-        flow = ovs_flow_tbl_lookup(&dp->table, &key);
+        flow = __ovs_flow_tbl_lookup(&dp->table, &key);
         if (!flow || !ovs_flow_cmp_unmasked_key(flow, &match)) {
                 err = -ENOENT;
                 goto unlock;
@@ -953,7 +969,7 @@ static int ovs_flow_cmd_del(struct sk_buff *skb, struct genl_info *info)
         if (err)
                 goto unlock;
 
-        flow = ovs_flow_tbl_lookup(&dp->table, &key);
+        flow = __ovs_flow_tbl_lookup(&dp->table, &key);
         if (!flow || !ovs_flow_cmp_unmasked_key(flow, &match)) {
                 err = -ENOENT;
                 goto unlock;
@@ -1067,6 +1083,7 @@ static size_t ovs_dp_cmd_msg_size(void)
 
         msgsize += nla_total_size(IFNAMSIZ);
         msgsize += nla_total_size(sizeof(struct ovs_dp_stats));
+        msgsize += nla_total_size(sizeof(struct ovs_dp_megaflow_stats));
 
         return msgsize;
 }
@@ -1076,6 +1093,7 @@ static int ovs_dp_cmd_fill_info(struct datapath *dp, struct sk_buff *skb,
 {
         struct ovs_header *ovs_header;
         struct ovs_dp_stats dp_stats;
+        struct ovs_dp_megaflow_stats dp_megaflow_stats;
         int err;
 
         ovs_header = genlmsg_put(skb, portid, seq, &dp_datapath_genl_family,
@@ -1091,8 +1109,14 @@ static int ovs_dp_cmd_fill_info(struct datapath *dp, struct sk_buff *skb,
         if (err)
                 goto nla_put_failure;
 
-        get_dp_stats(dp, &dp_stats);
-        if (nla_put(skb, OVS_DP_ATTR_STATS, sizeof(struct ovs_dp_stats), &dp_stats))
+        get_dp_stats(dp, &dp_stats, &dp_megaflow_stats);
+        if (nla_put(skb, OVS_DP_ATTR_STATS, sizeof(struct ovs_dp_stats),
+                        &dp_stats))
+                goto nla_put_failure;
+
+        if (nla_put(skb, OVS_DP_ATTR_MEGAFLOW_STATS,
+                        sizeof(struct ovs_dp_megaflow_stats),
+                        &dp_megaflow_stats))
                 goto nla_put_failure;
 
         return genlmsg_end(skb, ovs_header);
diff --git a/net/openvswitch/datapath.h b/net/openvswitch/datapath.h
index acfd4af8ca3a..d3d14a58aa91 100644
--- a/net/openvswitch/datapath.h
+++ b/net/openvswitch/datapath.h
@@ -46,11 +46,15 @@
  * @n_lost: Number of received packets that had no matching flow in the flow
  * table that could not be sent to userspace (normally due to an overflow in
  * one of the datapath's queues).
+ * @n_mask_hit: Number of masks looked up for flow match.
+ *   @n_mask_hit / (@n_hit + @n_missed)  will be the average masks looked
+ *   up per packet.
  */
 struct dp_stats_percpu {
         u64 n_hit;
         u64 n_missed;
         u64 n_lost;
+        u64 n_mask_hit;
         struct u64_stats_sync sync;
 };
 
diff --git a/net/openvswitch/flow_table.c b/net/openvswitch/flow_table.c
index 036e019f8c3c..536b4d2a42e2 100644
--- a/net/openvswitch/flow_table.c
+++ b/net/openvswitch/flow_table.c
@@ -430,13 +430,16 @@ static struct sw_flow *masked_flow_lookup(struct table_instance *ti,
 }
 
 struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *tbl,
-                                    const struct sw_flow_key *key)
+                                    const struct sw_flow_key *key,
+                                    u32 *n_mask_hit)
 {
         struct table_instance *ti = rcu_dereference(tbl->ti);
         struct sw_flow_mask *mask;
         struct sw_flow *flow;
 
+        *n_mask_hit = 0;
         list_for_each_entry_rcu(mask, &tbl->mask_list, list) {
+                (*n_mask_hit)++;
                 flow = masked_flow_lookup(ti, key, mask);
                 if (flow)  /* Found */
                         return flow;
@@ -444,6 +447,17 @@ struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *tbl,
         return NULL;
 }
 
+int ovs_flow_tbl_num_masks(const struct flow_table *table)
+{
+        struct sw_flow_mask *mask;
+        int num = 0;
+
+        list_for_each_entry(mask, &table->mask_list, list)
+                num++;
+
+        return num;
+}
+
 static struct table_instance *table_instance_expand(struct table_instance *ti)
 {
         return table_instance_rehash(ti, ti->n_buckets * 2);
diff --git a/net/openvswitch/flow_table.h b/net/openvswitch/flow_table.h
index 4db5f78b6f81..fbe45d5ad07d 100644
--- a/net/openvswitch/flow_table.h
+++ b/net/openvswitch/flow_table.h
@@ -66,10 +66,12 @@ int ovs_flow_tbl_flush(struct flow_table *flow_table);
 int ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow,
                         struct sw_flow_mask *mask);
 void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow);
+int  ovs_flow_tbl_num_masks(const struct flow_table *table);
 struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *table,
                                        u32 *bucket, u32 *idx);
 struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *,
-                                    const struct sw_flow_key *);
+                                    const struct sw_flow_key *,
+                                    u32 *n_mask_hit);
 
 bool ovs_flow_cmp_unmasked_key(const struct sw_flow *flow,
                                struct sw_flow_match *match);