From: John Lo <loj@cisco.com>
Date: Wed, 14 Dec 2016 20:42:45 +0000 (-0500)
Subject: Expand ethernet-input node speed-path for non-L2 paths
X-Git-Tag: v17.01-rc1~35
X-Git-Url: https://gerrit.fd.io/r/gitweb?a=commitdiff_plain;h=refs%2Fchanges%2F24%2F4324%2F2;p=vpp.git

Expand ethernet-input node speed-path for non-L2 paths

Improve ethernet-input speed path for untagged packets to also handle
L3 and other forwarding paths. In the IP4 forwarding path for untagged
IP4 packets, per packet clock count in ethernet-input node is reduced
to ~14 clocks from ~43 clocks.

Change-Id: I8e6f121820e056d6085dff3eb95d6913fc422f99
Signed-off-by: John Lo <loj@cisco.com>
---

diff --git a/vnet/vnet/ethernet/node.c b/vnet/vnet/ethernet/node.c
index 5a27fd0c750..c48e3f4237b 100755
--- a/vnet/vnet/ethernet/node.c
+++ b/vnet/vnet/ethernet/node.c
@@ -369,7 +369,7 @@ ethernet_input_inline (vlib_main_t * vm,
 	  e1 = vlib_buffer_get_current (b1);
 	  type1 = clib_net_to_host_u16 (e1->type);
 
-	  /* Speed-path for the untagged L2 case */
+	  /* Speed-path for the untagged case */
 	  if (PREDICT_TRUE (variant == ETHERNET_INPUT_VARIANT_ETHERNET
 			    && !ethernet_frame_is_tagged (type0)
 			    && !ethernet_frame_is_tagged (type1)))
@@ -404,12 +404,21 @@ ethernet_input_inline (vlib_main_t * vm,
 		  vnet_buffer (b1)->l2.l2_len = sizeof (ethernet_header_t);
 		  vnet_buffer (b1)->ethernet.start_of_ethernet_header =
 		    b1->current_data;
-		  goto ship_it01;
 		}
-	      /* FALLTHROUGH into the general case */
+	      else
+		{
+		  determine_next_node (em, variant, 0, type0, b0,
+				       &error0, &next0);
+		  vlib_buffer_advance (b0, sizeof (ethernet_header_t));
+		  determine_next_node (em, variant, 0, type1, b1,
+				       &error1, &next1);
+		  vlib_buffer_advance (b1, sizeof (ethernet_header_t));
+		}
+	      goto ship_it01;
 	    }
-	slowpath:
 
+	  /* Slow-path for the tagged case */
+	slowpath:
 	  parse_header (variant,
 			b0,
 			&type0,
@@ -578,7 +587,7 @@ ethernet_input_inline (vlib_main_t * vm,
 	  e0 = vlib_buffer_get_current (b0);
 	  type0 = clib_net_to_host_u16 (e0->type);
 
-	  /* Speed-path for the untagged L2 case */
+	  /* Speed-path for the untagged case */
 	  if (PREDICT_TRUE (variant == ETHERNET_INPUT_VARIANT_ETHERNET
 			    && !ethernet_frame_is_tagged (type0)))
 	    {
@@ -603,11 +612,17 @@ ethernet_input_inline (vlib_main_t * vm,
 		  vnet_buffer (b0)->l2.l2_len = sizeof (ethernet_header_t);
 		  vnet_buffer (b0)->ethernet.start_of_ethernet_header =
 		    b0->current_data;
-		  goto ship_it0;
 		}
-	      /* FALLTHROUGH into the general case */
+	      else
+		{
+		  determine_next_node (em, variant, 0, type0, b0,
+				       &error0, &next0);
+		  vlib_buffer_advance (b0, sizeof (ethernet_header_t));
+		}
+	      goto ship_it0;
 	    }
 
+	  /* Slow-path for the tagged case */
 	  parse_header (variant,
 			b0,
 			&type0,