vxlan_gpe: optimize encap performance

The patch can reduce 13 cycles per packet for the graph node
vxlan-gpe-encap and increases 5% or so vxlan_gpe encap throughput
on Haswell platform for the best case (All pkts have the same
sw_if_index).

Change-Id: I9c70fd3e0f2f0a9d922cf64970d0b0d51b772024
Signed-off-by: Zhiyong Yang <zhiyong.yang@intel.com>

diff --git a/src/vnet/vxlan-gpe/encap.c b/src/vnet/vxlan-gpe/encap.c
index e62a84e..9006b1b 100644 (file)
--- a/src/vnet/vxlan-gpe/encap.c
+++ b/src/vnet/vxlan-gpe/encap.c
@@ -164,6 +164,10 @@ vxlan_gpe_encap (vlib_main_t * vm,
   while (n_left_from > 0)
     {
       u32 n_left_to_next;
+      u32 sw_if_index0 = ~0, sw_if_index1 = ~0, len0, len1;
+      vnet_hw_interface_t *hi0, *hi1;
+      vxlan_gpe_tunnel_t *t0 = NULL, *t1 = NULL;
+      u8 is_ip4_0 = 0, is_ip4_1 = 0;
 
       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 
@@ -172,10 +176,6 @@ vxlan_gpe_encap (vlib_main_t * vm,
          u32 bi0, bi1;
          vlib_buffer_t *b0, *b1;
          u32 next0, next1;
-         u32 sw_if_index0, sw_if_index1, len0, len1;
-         vnet_hw_interface_t *hi0, *hi1;
-         vxlan_gpe_tunnel_t *t0, *t1;
-         u8 is_ip4_0, is_ip4_1;
 
          next0 = next1 = VXLAN_GPE_ENCAP_NEXT_IP4_LOOKUP;
 
@@ -205,23 +205,39 @@ vxlan_gpe_encap (vlib_main_t * vm,
          b0 = vlib_get_buffer (vm, bi0);
          b1 = vlib_get_buffer (vm, bi1);
 
-         /* 1-wide cache? */
-         sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX];
-         sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_TX];
-         hi0 =
-           vnet_get_sup_hw_interface (vnm,
-                                      vnet_buffer (b0)->sw_if_index
-                                      [VLIB_TX]);
-         hi1 =
-           vnet_get_sup_hw_interface (vnm,
-                                      vnet_buffer (b1)->sw_if_index
-                                      [VLIB_TX]);
-
-         t0 = pool_elt_at_index (ngm->tunnels, hi0->dev_instance);
-         t1 = pool_elt_at_index (ngm->tunnels, hi1->dev_instance);
+         /* get the flag "is_ip4" */
+         if (sw_if_index0 != vnet_buffer (b0)->sw_if_index[VLIB_TX])
+           {
+             sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX];
+             hi0 =
+               vnet_get_sup_hw_interface (vnm,
+                                          vnet_buffer (b0)->sw_if_index
+                                          [VLIB_TX]);
+             t0 = pool_elt_at_index (ngm->tunnels, hi0->dev_instance);
+             is_ip4_0 = (t0->flags & VXLAN_GPE_TUNNEL_IS_IPV4);
+           }
 
-         is_ip4_0 = (t0->flags & VXLAN_GPE_TUNNEL_IS_IPV4);
-         is_ip4_1 = (t1->flags & VXLAN_GPE_TUNNEL_IS_IPV4);
+         /* get the flag "is_ip4" */
+         if (sw_if_index1 != vnet_buffer (b1)->sw_if_index[VLIB_TX])
+           {
+             if (sw_if_index0 == vnet_buffer (b1)->sw_if_index[VLIB_TX])
+               {
+                 sw_if_index1 = sw_if_index0;
+                 hi1 = hi0;
+                 t1 = t0;
+                 is_ip4_1 = is_ip4_0;
+               }
+             else
+               {
+                 sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_TX];
+                 hi1 =
+                   vnet_get_sup_hw_interface (vnm,
+                                              vnet_buffer (b1)->sw_if_index
+                                              [VLIB_TX]);
+                 t1 = pool_elt_at_index (ngm->tunnels, hi1->dev_instance);
+                 is_ip4_1 = (t1->flags & VXLAN_GPE_TUNNEL_IS_IPV4);
+               }
+           }
 
          if (PREDICT_TRUE (is_ip4_0 == is_ip4_1))
            {
@@ -305,10 +321,6 @@ vxlan_gpe_encap (vlib_main_t * vm,
          u32 bi0;
          vlib_buffer_t *b0;
          u32 next0 = VXLAN_GPE_ENCAP_NEXT_IP4_LOOKUP;
-         u32 sw_if_index0, len0;
-         vnet_hw_interface_t *hi0;
-         vxlan_gpe_tunnel_t *t0;
-         u8 is_ip4_0;
 
          bi0 = from[0];
          to_next[0] = bi0;
@@ -319,16 +331,19 @@ vxlan_gpe_encap (vlib_main_t * vm,
 
          b0 = vlib_get_buffer (vm, bi0);
 
-         /* 1-wide cache? */
-         sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX];
-         hi0 =
-           vnet_get_sup_hw_interface (vnm,
-                                      vnet_buffer (b0)->sw_if_index
-                                      [VLIB_TX]);
+         /* get the flag "is_ip4" */
+         if (sw_if_index0 != vnet_buffer (b0)->sw_if_index[VLIB_TX])
+           {
+             sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX];
+             hi0 =
+               vnet_get_sup_hw_interface (vnm,
+                                          vnet_buffer (b0)->sw_if_index
+                                          [VLIB_TX]);
 
-         t0 = pool_elt_at_index (ngm->tunnels, hi0->dev_instance);
+             t0 = pool_elt_at_index (ngm->tunnels, hi0->dev_instance);
 
-         is_ip4_0 = (t0->flags & VXLAN_GPE_TUNNEL_IS_IPV4);
+             is_ip4_0 = (t0->flags & VXLAN_GPE_TUNNEL_IS_IPV4);
+           }
 
          vxlan_gpe_encap_one_inline (ngm, b0, t0, &next0, is_ip4_0);