devices: fix high vector rate per dispatch

Type: fix

Signed-off-by: Mohsin Kazmi <sykazmi@cisco.com>
Change-Id: Ibd23648483b38696271154237e81081480bb16e0

diff --git a/src/vnet/devices/af_packet/af_packet.c b/src/vnet/devices/af_packet/af_packet.c
index 4fb5463..5526d72 100644 (file)
--- a/src/vnet/devices/af_packet/af_packet.c
+++ b/src/vnet/devices/af_packet/af_packet.c
@@ -419,6 +419,7 @@ af_packet_create_if (af_packet_create_if_arg_t *arg)
   apif->mode = arg->mode;
   apif->hdrlen = hdrlen;
   apif->is_cksum_gso_enabled = is_cksum_gso_enabled;
+  apif->ss.is_save = 0;
 
   ret = af_packet_read_mtu (apif);
   if (ret != 0)

diff --git a/src/vnet/devices/af_packet/af_packet.h b/src/vnet/devices/af_packet/af_packet.h
index dd38e1b..217d2f6 100644 (file)
--- a/src/vnet/devices/af_packet/af_packet.h
+++ b/src/vnet/devices/af_packet/af_packet.h
@@ -38,6 +38,13 @@ typedef struct
   u8 host_if_name[64];
 } af_packet_if_detail_t;
 
+typedef struct
+{
+  u32 rx_frame_offset;
+  u32 num_pkts;
+  u8 is_save;
+} save_state_t;
+
 typedef struct
 {
   CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
@@ -63,6 +70,7 @@ typedef struct
   u32 queue_index;
   u32 host_mtu;
   af_packet_if_mode_t mode;
+  save_state_t ss;
 } af_packet_if_t;
 
 typedef struct

diff --git a/src/vnet/devices/af_packet/node.c b/src/vnet/devices/af_packet/node.c
index a42e3e0..06012fd 100644 (file)
--- a/src/vnet/devices/af_packet/node.c
+++ b/src/vnet/devices/af_packet/node.c
@@ -256,15 +256,21 @@ af_packet_device_input_fn (vlib_main_t *vm, vlib_node_runtime_t *node,
       vnet_feature_start_device_input_x1 (apif->sw_if_index, &next_index, &bt);
     }
 
-  while ((((block_desc_t *) (block_start = apif->rx_ring[block]))
-           ->hdr.bh1.block_status &
-         TP_STATUS_USER) != 0)
+  if ((((block_desc_t *) (block_start = apif->rx_ring[block]))
+        ->hdr.bh1.block_status &
+       TP_STATUS_USER) != 0)
     {
       u32 n_required = 0;
+      bd = (block_desc_t *) block_start;
 
-      if (PREDICT_FALSE (num_pkts == 0))
+      if (PREDICT_FALSE (apif->ss.is_save))
+       {
+         num_pkts = apif->ss.num_pkts;
+         rx_frame_offset = apif->ss.rx_frame_offset;
+         apif->ss.is_save = 0;
+       }
+      else
        {
-         bd = (block_desc_t *) block_start;
          num_pkts = bd->hdr.bh1.num_pkts;
          rx_frame_offset = sizeof (block_desc_t);
        }
@@ -280,14 +286,14 @@ af_packet_device_input_fn (vlib_main_t *vm, vlib_node_runtime_t *node,
          _vec_len (apm->rx_buffers[thread_index]) = n_free_bufs;
        }
 
-      while (num_pkts && (n_free_bufs > min_bufs))
+      while (num_pkts && (n_free_bufs >= min_bufs))
        {
          u32 next0 = next_index;
          u32 n_left_to_next;
 
          vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 
-         while (num_pkts && n_left_to_next && (n_free_bufs > min_bufs))
+         while (num_pkts && n_left_to_next && (n_free_bufs >= min_bufs))
            {
              tph = (tpacket3_hdr_t *) (block_start + rx_frame_offset);
 
@@ -308,15 +314,15 @@ af_packet_device_input_fn (vlib_main_t *vm, vlib_node_runtime_t *node,
                  (vnet_virtio_net_hdr_t *) ((u8 *) tph + tph->tp_mac -
                                             sizeof (vnet_virtio_net_hdr_t));
 
+             // save current state and return
              if (PREDICT_FALSE (((data_len / n_buffer_bytes) + 1) >
                                 vec_len (apm->rx_buffers[thread_index])))
                {
-                 vec_validate (apm->rx_buffers[thread_index],
-                               VLIB_FRAME_SIZE + n_free_bufs - 1);
-                 n_free_bufs += vlib_buffer_alloc (
-                   vm, &apm->rx_buffers[thread_index][n_free_bufs],
-                   VLIB_FRAME_SIZE);
-                 _vec_len (apm->rx_buffers[thread_index]) = n_free_bufs;
+                 apif->ss.rx_frame_offset = rx_frame_offset;
+                 apif->ss.num_pkts = num_pkts;
+                 apif->ss.is_save = 1;
+                 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+                 goto done;
                }
 
              while (data_len)
@@ -475,9 +481,25 @@ af_packet_device_input_fn (vlib_main_t *vm, vlib_node_runtime_t *node,
          bd->hdr.bh1.block_status = TP_STATUS_KERNEL;
          block = (block + 1) % block_nr;
        }
+      else
+       {
+         apif->ss.rx_frame_offset = rx_frame_offset;
+         apif->ss.num_pkts = num_pkts;
+         apif->ss.is_save = 1;
+       }
     }
 
   apif->next_rx_block = block;
+
+done:
+
+  if ((((block_desc_t *) (block_start = apif->rx_ring[block]))
+        ->hdr.bh1.block_status &
+       TP_STATUS_USER) != 0)
+    vlib_node_set_state (vm, node->node_index, VLIB_NODE_STATE_POLLING);
+  else
+    vlib_node_set_state (vm, node->node_index, VLIB_NODE_STATE_INTERRUPT);
+
   vlib_increment_combined_counter
     (vnet_get_main ()->interface_main.combined_sw_if_counters
      + VNET_INTERFACE_COUNTER_RX,