Improve Load-Balance MAPs

- only build them for popular path-lists (where popular means more than 64 children)
   the reason to have a map is to improve convergence speed for recursive prefixes - if there are only a few this technique is not needed
- only build them when there is at least one path that has recursive constraints, i.e. a path that can 'fail' in a PIC scenario.
- Use the MAPS in the switch path.
- PIC test cases for functionality (not convergence performance)

Change-Id: I70705444c8469d22b07ae34be82cfb6a01358e10
Signed-off-by: Neale Ranns <nranns@cisco.com>

2 files changed, 33 insertions, 1 deletions

diff --git a/src/vnet/dpo/load_balance.c b/src/vnet/dpo/load_balance.c
index 6b0eda0e8b1..af054f1c3f4 100644
--- a/src/vnet/dpo/load_balance.c
+++ b/src/vnet/dpo/load_balance.c
@@ -118,7 +118,8 @@ load_balance_format (index_t lbi,
     buckets = load_balance_get_buckets(lb);
 
     s = format(s, "%U: ", format_dpo_type, DPO_LOAD_BALANCE);
-    s = format(s, "[index:%d buckets:%d ", lbi, lb->lb_n_buckets);
+    s = format(s, "[proto:%U ", format_dpo_proto, lb->lb_proto);
+    s = format(s, "index:%d buckets:%d ", lbi, lb->lb_n_buckets);
     s = format(s, "uRPF:%d ", lb->lb_urpf);
     s = format(s, "to:[%Ld:%Ld]", to.packets, to.bytes);
     if (0 != via.packets)
diff --git a/src/vnet/dpo/load_balance_map.h b/src/vnet/dpo/load_balance_map.h
index 454bf4b3763..237f24b0138 100644
--- a/src/vnet/dpo/load_balance_map.h
+++ b/src/vnet/dpo/load_balance_map.h
@@ -73,6 +73,37 @@ load_balance_map_get (index_t lbmi)
     return (pool_elt_at_index(load_balance_map_pool, lbmi));
 }
 
+static inline u16
+load_balance_map_translate (index_t lbmi,
+                            u16 bucket)
+{
+    load_balance_map_t*lbm;
+
+    lbm = load_balance_map_get(lbmi);
+
+    return (lbm->lbm_buckets[bucket]);
+}
+
+static inline const dpo_id_t *
+load_balance_get_fwd_bucket (const load_balance_t *lb,
+                             u16 bucket)
+{
+    ASSERT(bucket < lb->lb_n_buckets);
+
+    if (INDEX_INVALID != lb->lb_map)
+    {
+        bucket = load_balance_map_translate(lb->lb_map, bucket);
+    }
+
+    if (PREDICT_TRUE(LB_HAS_INLINE_BUCKETS(lb)))
+    {
+	return (&lb->lb_buckets_inline[bucket]);
+    }
+    else
+    {
+	return (&lb->lb_buckets[bucket]);
+    }
+}
 
 extern void load_balance_map_module_init(void);