L2-input: use vlib_buffer_enqueue_to_next 83/14783/2
authorNeale Ranns <nranns@cisco.com>
Wed, 12 Sep 2018 13:42:50 +0000 (09:42 -0400)
committerDamjan Marion <dmarion@me.com>
Thu, 13 Sep 2018 00:25:20 +0000 (00:25 +0000)
use the same trick as l2-ouput to group the processing of packets
on the same interface.

Change-Id: Ib2a6a1b5f362372936197f5bb2fdd0fe9439226b
Signed-off-by: Neale Ranns <nranns@cisco.com>
src/vnet/ethernet/packet.h
src/vnet/l2/l2_input.c

index d70960b..04ce420 100644 (file)
@@ -64,20 +64,20 @@ typedef struct
 
 /* I/G bit: individual (unicast)/group (broadcast/multicast). */
 always_inline uword
-ethernet_address_cast (u8 * a)
+ethernet_address_cast (const u8 * a)
 {
   return (a[0] >> 0) & 1;
 }
 
 always_inline int
-ethernet_address_is_broadcast (u8 * a)
+ethernet_address_is_broadcast (const u8 * a)
 {
   return clib_mem_unaligned (a, u32) == 0xffffffff &&
     clib_mem_unaligned (a + 4, u16) == 0xffff;
 }
 
 always_inline uword
-ethernet_address_is_locally_administered (u8 * a)
+ethernet_address_is_locally_administered (const u8 * a)
 {
   return (a[0] >> 1) & 1;
 }
index 7e41c88..fbf4a6b 100644 (file)
@@ -138,9 +138,85 @@ typedef enum
   L2INPUT_N_NEXT,
 } l2input_next_t;
 
+static_always_inline u32
+l2_input_classiy_unicast (vlib_buffer_t * b, const ethernet_header_t * h0)
+{
+  u32 feat_mask = ~0;
+  u8 *l3h0 = (u8 *) h0 + vnet_buffer (b)->l2.l2_len;
+
+#define get_u16(addr) ( *((u16 *)(addr)) )
+  u16 ethertype = clib_net_to_host_u16 (get_u16 (l3h0 - 2));
+  u8 protocol = ((ip6_header_t *) l3h0)->protocol;
+
+  /* Disable bridge forwarding (flooding will execute instead if not xconnect) */
+  feat_mask &= ~(L2INPUT_FEAT_FWD |
+                L2INPUT_FEAT_UU_FLOOD | L2INPUT_FEAT_GBP_FWD);
+
+  /* Disable ARP-term for non-ARP and non-ICMP6 packet */
+  if (ethertype != ETHERNET_TYPE_ARP &&
+      (ethertype != ETHERNET_TYPE_IP6 || protocol != IP_PROTOCOL_ICMP6))
+    feat_mask &= ~(L2INPUT_FEAT_ARP_TERM);
+
+  /*
+   * For packet from BVI - set SHG of ARP request or ICMPv6 neighbor
+   * solicitation packet from BVI to 0 so it can also flood to VXLAN
+   * tunnels or other ports with the same SHG as that of the BVI.
+   */
+  else if (PREDICT_FALSE (vnet_buffer (b)->sw_if_index[VLIB_TX] ==
+                         L2INPUT_BVI))
+    {
+      if (ethertype == ETHERNET_TYPE_ARP)
+       {
+         ethernet_arp_header_t *arp0 = (ethernet_arp_header_t *) l3h0;
+         if (arp0->opcode ==
+             clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_request))
+           vnet_buffer (b)->l2.shg = 0;
+       }
+      else                     /* must be ICMPv6 */
+       {
+         ip6_header_t *iph0 = (ip6_header_t *) l3h0;
+         icmp6_neighbor_solicitation_or_advertisement_header_t *ndh0;
+         ndh0 = ip6_next_header (iph0);
+         if (ndh0->icmp.type == ICMP6_neighbor_solicitation)
+           vnet_buffer (b)->l2.shg = 0;
+       }
+    }
+
+  return (feat_mask);
+}
 
 static_always_inline void
-classify_and_dispatch (l2input_main_t * msm, vlib_buffer_t * b0, u32 * next0)
+l2_input_classify_bridge (l2_bridge_domain_t * bd_config,
+                         u16 bd_index,
+                         u32 sw_if_index, vlib_buffer_t * b, u32 * feat_mask)
+{
+  /* save BD ID for next feature graph nodes */
+  vnet_buffer (b)->l2.bd_index = bd_index;
+
+  /* Save bridge domain and interface seq_num */
+  /* *INDENT-OFF* */
+  l2fib_seq_num_t sn = {
+    .swif = *l2fib_swif_seq_num(sw_if_index),
+    .bd = bd_config->seq_num,
+  };
+  /* *INDENT-ON* */
+  vnet_buffer (b)->l2.l2fib_sn = sn.as_u16;;
+  vnet_buffer (b)->l2.bd_age = bd_config->mac_age;
+
+  /*
+   * Process bridge domain feature enables.
+   * To perform learning/flooding/forwarding, the corresponding bit
+   * must be enabled in both the input interface config and in the
+   * bridge domain config. In the bd_bitmap, bits for features other
+   * than learning/flooding/forwarding should always be set.
+   */
+  *feat_mask = *feat_mask & bd_config->feature_bitmap;
+}
+
+static_always_inline void
+classify_and_dispatch (l2input_main_t * msm,
+                      u16 n_left,
+                      u32 sw_if_index, vlib_buffer_t ** b, u16 * next)
 {
   /*
    * Load L2 input feature struct
@@ -156,119 +232,202 @@ classify_and_dispatch (l2input_main_t * msm, vlib_buffer_t * b0, u32 * next0)
    *   set tx sw-if-handle
    */
 
-  u32 feat_mask = ~0;
-  u32 sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
-  ethernet_header_t *h0 = vlib_buffer_get_current (b0);
+  l2_input_config_t *config;
 
   /* Get config for the input interface */
-  l2_input_config_t *config = vec_elt_at_index (msm->configs, sw_if_index0);
+  config = vec_elt_at_index (msm->configs, sw_if_index);
 
-  /* Save split horizon group */
-  vnet_buffer (b0)->l2.shg = config->shg;
-
-  /* determine layer2 kind for stat and mask */
-  if (PREDICT_FALSE (ethernet_address_cast (h0->dst_address)))
+  while (n_left > 8)
     {
-      u8 *l3h0 = (u8 *) h0 + vnet_buffer (b0)->l2.l2_len;
+      const ethernet_header_t *h0, *h1, *h2, *h3;
+      u32 fm0, fm1, fm2, fm3;
+      u32 fb0, fb1, fb2, fb3;
 
-#define get_u16(addr) ( *((u16 *)(addr)) )
-      u16 ethertype = clib_net_to_host_u16 (get_u16 (l3h0 - 2));
-      u8 protocol = ((ip6_header_t *) l3h0)->protocol;
+      if (n_left >= 4)
+       {
+         vlib_prefetch_buffer_header (b[0], LOAD);
+         vlib_prefetch_buffer_header (b[1], LOAD);
+         vlib_prefetch_buffer_header (b[2], LOAD);
+         vlib_prefetch_buffer_header (b[3], LOAD);
+       }
 
-      /* Disable bridge forwarding (flooding will execute instead if not xconnect) */
-      feat_mask &= ~(L2INPUT_FEAT_FWD |
-                    L2INPUT_FEAT_UU_FLOOD | L2INPUT_FEAT_GBP_FWD);
+      fm0 = fm1 = fm2 = fm3 = ~0;
+      h0 = vlib_buffer_get_current (b[0]);
+      h1 = vlib_buffer_get_current (b[1]);
+      h2 = vlib_buffer_get_current (b[2]);
+      h3 = vlib_buffer_get_current (b[3]);
 
-      /* Disable ARP-term for non-ARP and non-ICMP6 packet */
-      if (ethertype != ETHERNET_TYPE_ARP &&
-         (ethertype != ETHERNET_TYPE_IP6 || protocol != IP_PROTOCOL_ICMP6))
-       feat_mask &= ~(L2INPUT_FEAT_ARP_TERM);
+      /* Save split horizon group */
+      vnet_buffer (b[0])->l2.shg = config->shg;
+      vnet_buffer (b[1])->l2.shg = config->shg;
+      vnet_buffer (b[2])->l2.shg = config->shg;
+      vnet_buffer (b[3])->l2.shg = config->shg;
 
-      /*
-       * For packet from BVI - set SHG of ARP request or ICMPv6 neighbor
-       * solicitation packet from BVI to 0 so it can also flood to VXLAN
-       * tunnels or other ports with the same SHG as that of the BVI.
-       */
-      else if (PREDICT_FALSE (vnet_buffer (b0)->sw_if_index[VLIB_TX] ==
-                             L2INPUT_BVI))
+      /* determine layer2 kind for stat and mask */
+      if (PREDICT_FALSE (ethernet_address_cast (h0->dst_address)))
        {
-         if (ethertype == ETHERNET_TYPE_ARP)
-           {
-             ethernet_arp_header_t *arp0 = (ethernet_arp_header_t *) l3h0;
-             if (arp0->opcode ==
-                 clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_request))
-               vnet_buffer (b0)->l2.shg = 0;
-           }
-         else                  /* must be ICMPv6 */
-           {
-             ip6_header_t *iph0 = (ip6_header_t *) l3h0;
-             icmp6_neighbor_solicitation_or_advertisement_header_t *ndh0;
-             ndh0 = ip6_next_header (iph0);
-             if (ndh0->icmp.type == ICMP6_neighbor_solicitation)
-               vnet_buffer (b0)->l2.shg = 0;
-           }
+         fm0 = l2_input_classiy_unicast (b[0], h0);
+       }
+      else
+       {
+         if (PREDICT_FALSE (sw_if_index == L2INPUT_BVI))
+           vnet_buffer (b[0])->l2.shg = 0;
+       }
+      if (PREDICT_FALSE (ethernet_address_cast (h1->dst_address)))
+       {
+         fm1 = l2_input_classiy_unicast (b[1], h1);
+       }
+      else
+       {
+         if (PREDICT_FALSE (sw_if_index == L2INPUT_BVI))
+           vnet_buffer (b[1])->l2.shg = 0;
+       }
+      if (PREDICT_FALSE (ethernet_address_cast (h2->dst_address)))
+       {
+         fm2 = l2_input_classiy_unicast (b[2], h2);
+       }
+      else
+       {
+         if (PREDICT_FALSE (sw_if_index == L2INPUT_BVI))
+           vnet_buffer (b[1])->l2.shg = 0;
+       }
+      if (PREDICT_FALSE (ethernet_address_cast (h3->dst_address)))
+       {
+         fm3 = l2_input_classiy_unicast (b[3], h3);
+       }
+      else
+       {
+         if (PREDICT_FALSE (sw_if_index == L2INPUT_BVI))
+           vnet_buffer (b[1])->l2.shg = 0;
+       }
+
+      if (config->bridge)
+       {
+         /* Do bridge-domain processing */
+         l2_bridge_domain_t *bd_config;
+         u16 bd_index;
+
+         bd_index = config->bd_index;
+         bd_config = vec_elt_at_index (msm->bd_configs, bd_index);
+
+         l2_input_classify_bridge (bd_config, bd_index, sw_if_index,
+                                   b[0], &fm0);
+         l2_input_classify_bridge (bd_config, bd_index, sw_if_index,
+                                   b[1], &fm1);
+         l2_input_classify_bridge (bd_config, bd_index, sw_if_index,
+                                   b[2], &fm2);
+         l2_input_classify_bridge (bd_config, bd_index, sw_if_index,
+                                   b[3], &fm3);
+       }
+      else if (config->xconnect)
+       {
+         /* Set the output interface */
+         vnet_buffer (b[0])->sw_if_index[VLIB_TX] =
+           config->output_sw_if_index;
+         vnet_buffer (b[1])->sw_if_index[VLIB_TX] =
+           config->output_sw_if_index;
+         vnet_buffer (b[2])->sw_if_index[VLIB_TX] =
+           config->output_sw_if_index;
+         vnet_buffer (b[3])->sw_if_index[VLIB_TX] =
+           config->output_sw_if_index;
        }
+      else
+       {
+         fm0 = L2INPUT_FEAT_DROP;
+         fm1 = L2INPUT_FEAT_DROP;
+         fm2 = L2INPUT_FEAT_DROP;
+         fm3 = L2INPUT_FEAT_DROP;
+       }
+
+      /* mask out features from bitmap using packet type and bd config */
+      fb0 = config->feature_bitmap & fm0;
+      fb1 = config->feature_bitmap & fm1;
+      fb2 = config->feature_bitmap & fm2;
+      fb3 = config->feature_bitmap & fm3;
+
+      /* save for next feature graph nodes */
+      vnet_buffer (b[0])->l2.feature_bitmap = fb0;
+      vnet_buffer (b[1])->l2.feature_bitmap = fb1;
+      vnet_buffer (b[2])->l2.feature_bitmap = fb2;
+      vnet_buffer (b[3])->l2.feature_bitmap = fb3;
+
+      /* Determine the next node */
+      *next = feat_bitmap_get_next_node_index (msm->feat_next_node_index,
+                                              fb0);
+      next++;
+      *next = feat_bitmap_get_next_node_index (msm->feat_next_node_index,
+                                              fb1);
+      next++;
+      *next = feat_bitmap_get_next_node_index (msm->feat_next_node_index,
+                                              fb2);
+      next++;
+      *next = feat_bitmap_get_next_node_index (msm->feat_next_node_index,
+                                              fb3);
+      next++;
+
+      b += 4;
+      n_left -= 4;
     }
-  else
+  while (n_left)
     {
-      /*
-       * For packet from BVI - set SHG of unicast packet from BVI to 0 so it
-       * is not dropped on output to VXLAN tunnels or other ports with the
-       * same SHG as that of the BVI.
-       */
-      if (PREDICT_FALSE (vnet_buffer (b0)->sw_if_index[VLIB_TX] ==
-                        L2INPUT_BVI))
-       vnet_buffer (b0)->l2.shg = 0;
-    }
+      const ethernet_header_t *h0;
+      u32 fm0, fb0;
 
+      fm0 = ~0;
+      h0 = vlib_buffer_get_current (b[0]);
 
-  if (config->bridge)
-    {
-      /* Do bridge-domain processing */
-      u16 bd_index0 = config->bd_index;
-      /* save BD ID for next feature graph nodes */
-      vnet_buffer (b0)->l2.bd_index = bd_index0;
+      /* Save split horizon group */
+      vnet_buffer (b[0])->l2.shg = config->shg;
 
-      /* Get config for the bridge domain interface */
-      l2_bridge_domain_t *bd_config =
-       vec_elt_at_index (msm->bd_configs, bd_index0);
+      /* determine layer2 kind for stat and mask */
+      if (PREDICT_FALSE (ethernet_address_cast (h0->dst_address)))
+       {
+         fm0 = l2_input_classiy_unicast (b[0], h0);
+       }
+      else
+       {
+         /*
+          * For packet from BVI - set SHG of unicast packet from BVI to 0 so it
+          * is not dropped on output to VXLAN tunnels or other ports with the
+          * same SHG as that of the BVI.
+          */
+         if (PREDICT_FALSE (sw_if_index == L2INPUT_BVI))
+           vnet_buffer (b[0])->l2.shg = 0;
+       }
 
-      /* Save bridge domain and interface seq_num */
-      /* *INDENT-OFF* */
-      l2fib_seq_num_t sn = {
-        .swif = *l2fib_swif_seq_num(sw_if_index0),
-       .bd = bd_config->seq_num,
-      };
-      /* *INDENT-ON* */
-      vnet_buffer (b0)->l2.l2fib_sn = sn.as_u16;;
-      vnet_buffer (b0)->l2.bd_age = bd_config->mac_age;
+      if (config->bridge)
+       {
+         /* Do bridge-domain processing */
+         u16 bd_index = config->bd_index;
+         l2_bridge_domain_t *bd_config =
+           vec_elt_at_index (msm->bd_configs, bd_index);
 
-      /*
-       * Process bridge domain feature enables.
-       * To perform learning/flooding/forwarding, the corresponding bit
-       * must be enabled in both the input interface config and in the
-       * bridge domain config. In the bd_bitmap, bits for features other
-       * than learning/flooding/forwarding should always be set.
-       */
-      feat_mask = feat_mask & bd_config->feature_bitmap;
-    }
-  else if (config->xconnect)
-    {
-      /* Set the output interface */
-      vnet_buffer (b0)->sw_if_index[VLIB_TX] = config->output_sw_if_index;
-    }
-  else
-    feat_mask = L2INPUT_FEAT_DROP;
+         l2_input_classify_bridge (bd_config, bd_index, sw_if_index,
+                                   b[0], &fm0);
+       }
+      else if (config->xconnect)
+       {
+         /* Set the output interface */
+         vnet_buffer (b[0])->sw_if_index[VLIB_TX] =
+           config->output_sw_if_index;
+       }
+      else
+       fm0 = L2INPUT_FEAT_DROP;
+
+      /* mask out features from bitmap using packet type and bd config */
+      fb0 = config->feature_bitmap & fm0;
 
-  /* mask out features from bitmap using packet type and bd config */
-  u32 feature_bitmap = config->feature_bitmap & feat_mask;
+      /* save for next feature graph nodes */
+      vnet_buffer (b[0])->l2.feature_bitmap = fb0;
 
-  /* save for next feature graph nodes */
-  vnet_buffer (b0)->l2.feature_bitmap = feature_bitmap;
+      /* Determine the next node */
+      *next = feat_bitmap_get_next_node_index (msm->feat_next_node_index,
+                                              fb0);
 
-  /* Determine the next node */
-  *next0 = feat_bitmap_get_next_node_index (msm->feat_next_node_index,
-                                           feature_bitmap);
+      next += 1;
+      b += 1;
+      n_left -= 1;
+    }
 }
 
 static_always_inline uword
@@ -276,169 +435,88 @@ l2input_node_inline (vlib_main_t * vm,
                     vlib_node_runtime_t * node, vlib_frame_t * frame,
                     int do_trace)
 {
-  u32 n_left_from, *from, *to_next;
-  l2input_next_t next_index;
+  u32 n_left, *from;
   l2input_main_t *msm = &l2input_main;
+  vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
+  u16 nexts[VLIB_FRAME_SIZE];
+  u32 sw_if_indices[VLIB_FRAME_SIZE], *sw_if_index;
 
   from = vlib_frame_vector_args (frame);
-  n_left_from = frame->n_vectors;      /* number of packets to process */
-  next_index = node->cached_next_index;
+  n_left = frame->n_vectors;   /* number of packets to process */
+  vlib_get_buffers (vm, from, bufs, n_left);
+  b = bufs;
+  sw_if_index = sw_if_indices;
 
-  while (n_left_from > 0)
+  /* extract data from buffer metadata */
+  while (n_left >= 8)
+    {
+      /* Prefetch the buffer header for the N+2 loop iteration */
+      vlib_prefetch_buffer_header (b[4], LOAD);
+      vlib_prefetch_buffer_header (b[5], LOAD);
+      vlib_prefetch_buffer_header (b[6], LOAD);
+      vlib_prefetch_buffer_header (b[7], LOAD);
+
+      sw_if_index[0] = vnet_buffer (b[0])->sw_if_index[VLIB_RX];
+      sw_if_index[1] = vnet_buffer (b[1])->sw_if_index[VLIB_RX];
+      sw_if_index[2] = vnet_buffer (b[2])->sw_if_index[VLIB_RX];
+      sw_if_index[3] = vnet_buffer (b[3])->sw_if_index[VLIB_RX];
+
+      /* next */
+      sw_if_index += 4;
+      n_left -= 4;
+      b += 4;
+    }
+  while (n_left)
     {
-      u32 n_left_to_next;
+      sw_if_index[0] = vnet_buffer (b[0])->sw_if_index[VLIB_RX];
 
-      /* get space to enqueue frame to graph node "next_index" */
-      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+      /* next */
+      sw_if_index += 1;
+      n_left -= 1;
+      b += 1;
+    }
 
-      while (n_left_from >= 8 && n_left_to_next >= 4)
-       {
-         u32 bi0, bi1, bi2, bi3;
-         vlib_buffer_t *b0, *b1, *b2, *b3;
-         u32 next0, next1, next2, next3;
-         u32 sw_if_index0, sw_if_index1, sw_if_index2, sw_if_index3;
-
-         /* Prefetch next iteration. */
-         {
-           vlib_buffer_t *p4, *p5, *p6, *p7;
-
-           p4 = vlib_get_buffer (vm, from[4]);
-           p5 = vlib_get_buffer (vm, from[5]);
-           p6 = vlib_get_buffer (vm, from[6]);
-           p7 = vlib_get_buffer (vm, from[7]);
-
-           /* Prefetch the buffer header and packet for the N+2 loop iteration */
-           vlib_prefetch_buffer_header (p4, LOAD);
-           vlib_prefetch_buffer_header (p5, LOAD);
-           vlib_prefetch_buffer_header (p6, LOAD);
-           vlib_prefetch_buffer_header (p7, LOAD);
-
-           CLIB_PREFETCH (p4->data, CLIB_CACHE_LINE_BYTES, STORE);
-           CLIB_PREFETCH (p5->data, CLIB_CACHE_LINE_BYTES, STORE);
-           CLIB_PREFETCH (p6->data, CLIB_CACHE_LINE_BYTES, STORE);
-           CLIB_PREFETCH (p7->data, CLIB_CACHE_LINE_BYTES, STORE);
-
-           /*
-            * Don't bother prefetching the bridge-domain config (which
-            * depends on the input config above). Only a small number of
-            * bridge domains are expected. Plus the structure is small
-            * and several fit in a cache line.
-            */
-         }
-
-         /* speculatively enqueue b0 and b1 to the current next frame */
-         /* bi is "buffer index", b is pointer to the buffer */
-         to_next[0] = bi0 = from[0];
-         to_next[1] = bi1 = from[1];
-         to_next[2] = bi2 = from[2];
-         to_next[3] = bi3 = from[3];
-         from += 4;
-         to_next += 4;
-         n_left_from -= 4;
-         n_left_to_next -= 4;
-
-         b0 = vlib_get_buffer (vm, bi0);
-         b1 = vlib_get_buffer (vm, bi1);
-         b2 = vlib_get_buffer (vm, bi2);
-         b3 = vlib_get_buffer (vm, bi3);
-
-         if (do_trace)
-           {
-             /* RX interface handles */
-             sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
-             sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
-             sw_if_index2 = vnet_buffer (b2)->sw_if_index[VLIB_RX];
-             sw_if_index3 = vnet_buffer (b3)->sw_if_index[VLIB_RX];
+  n_left = frame->n_vectors;
 
-             if (b0->flags & VLIB_BUFFER_IS_TRACED)
-               {
-                 ethernet_header_t *h0 = vlib_buffer_get_current (b0);
-                 l2input_trace_t *t =
-                   vlib_add_trace (vm, node, b0, sizeof (*t));
-                 t->sw_if_index = sw_if_index0;
-                 clib_memcpy (t->src, h0->src_address, 6);
-                 clib_memcpy (t->dst, h0->dst_address, 6);
-               }
-             if (b1->flags & VLIB_BUFFER_IS_TRACED)
-               {
-                 ethernet_header_t *h1 = vlib_buffer_get_current (b1);
-                 l2input_trace_t *t =
-                   vlib_add_trace (vm, node, b1, sizeof (*t));
-                 t->sw_if_index = sw_if_index1;
-                 clib_memcpy (t->src, h1->src_address, 6);
-                 clib_memcpy (t->dst, h1->dst_address, 6);
-               }
-             if (b2->flags & VLIB_BUFFER_IS_TRACED)
-               {
-                 ethernet_header_t *h2 = vlib_buffer_get_current (b2);
-                 l2input_trace_t *t =
-                   vlib_add_trace (vm, node, b2, sizeof (*t));
-                 t->sw_if_index = sw_if_index2;
-                 clib_memcpy (t->src, h2->src_address, 6);
-                 clib_memcpy (t->dst, h2->dst_address, 6);
-               }
-             if (b3->flags & VLIB_BUFFER_IS_TRACED)
-               {
-                 ethernet_header_t *h3 = vlib_buffer_get_current (b3);
-                 l2input_trace_t *t =
-                   vlib_add_trace (vm, node, b3, sizeof (*t));
-                 t->sw_if_index = sw_if_index3;
-                 clib_memcpy (t->src, h3->src_address, 6);
-                 clib_memcpy (t->dst, h3->dst_address, 6);
-               }
-           }
+  while (n_left)
+    {
+      u16 count, *next;
+      u16 off = frame->n_vectors - n_left;
+      b = bufs + off;
 
-         classify_and_dispatch (msm, b0, &next0);
-         classify_and_dispatch (msm, b1, &next1);
-         classify_and_dispatch (msm, b2, &next2);
-         classify_and_dispatch (msm, b3, &next3);
-
-         /* verify speculative enqueues, maybe switch current next frame */
-         /* if next0==next1==next_index then nothing special needs to be done */
-         vlib_validate_buffer_enqueue_x4 (vm, node, next_index,
-                                          to_next, n_left_to_next,
-                                          bi0, bi1, bi2, bi3,
-                                          next0, next1, next2, next3);
-       }
+      sw_if_index = sw_if_indices + off;
+      next = nexts + off;
+
+      count = clib_count_equal_u32 (sw_if_index, n_left);
+      n_left -= count;
+
+      classify_and_dispatch (msm, count, sw_if_index[0], b, next);
+    }
 
-      while (n_left_from > 0 && n_left_to_next > 0)
+  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
+    {
+      n_left = frame->n_vectors;       /* number of packets to process */
+      b = bufs;
+
+      while (n_left)
        {
-         u32 bi0;
-         vlib_buffer_t *b0;
-         u32 next0;
-         u32 sw_if_index0;
-
-         /* speculatively enqueue b0 to the current next frame */
-         bi0 = from[0];
-         to_next[0] = bi0;
-         from += 1;
-         to_next += 1;
-         n_left_from -= 1;
-         n_left_to_next -= 1;
-
-         b0 = vlib_get_buffer (vm, bi0);
-
-         if (do_trace && PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
+         if (PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED))
            {
-             ethernet_header_t *h0 = vlib_buffer_get_current (b0);
-             l2input_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
-             sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
-             t->sw_if_index = sw_if_index0;
+             ethernet_header_t *h0 = vlib_buffer_get_current (b[0]);
+             l2input_trace_t *t =
+               vlib_add_trace (vm, node, b[0], sizeof (*t));
+
+             t->sw_if_index = vnet_buffer (b[0])->sw_if_index[VLIB_RX];
              clib_memcpy (t->src, h0->src_address, 6);
              clib_memcpy (t->dst, h0->dst_address, 6);
            }
-
-         classify_and_dispatch (msm, b0, &next0);
-
-         /* verify speculative enqueue, maybe switch current next frame */
-         vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
-                                          to_next, n_left_to_next,
-                                          bi0, next0);
+         /* next */
+         n_left--;
+         b++;
        }
-
-      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
     }
 
+  vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
   vlib_node_increment_counter (vm, l2input_node.index,
                               L2INPUT_ERROR_L2INPUT, frame->n_vectors);