From: Florin Coras <fcoras@cisco.com>
Date: Sat, 30 Jun 2018 18:27:59 +0000 (-0700)
Subject: tcp: fix single loop prefetch
X-Git-Tag: v18.07-rc1~65
X-Git-Url: https://gerrit.fd.io/r/gitweb?p=vpp.git;a=commitdiff_plain;h=91ca462b58007299621a9fa6b6c06ed0b8a6040a

tcp: fix single loop prefetch

Also add single loop prefetch in session tx

Change-Id: Ib2725a2552fcc1a65050d7a2eb10491a7b34db62
Signed-off-by: Florin Coras <fcoras@cisco.com>
---

diff --git a/src/vnet/session/session_node.c b/src/vnet/session/session_node.c
index 00874634551..aec353d3367 100644
--- a/src/vnet/session/session_node.c
+++ b/src/vnet/session/session_node.c
@@ -483,7 +483,13 @@ session_tx_fifo_read_and_snd_i (vlib_main_t * vm, vlib_node_runtime_t * node,
       vlib_buffer_t *b0;
       u32 bi0;
 
-      ASSERT (n_bufs >= 1);
+      if (n_left > 1)
+	{
+	  pbi = smm->tx_buffers[thread_index][n_bufs - 2];
+	  pb = vlib_get_buffer (vm, pbi);
+	  vlib_prefetch_buffer_header (pb, STORE);
+	}
+
       to_next[0] = bi0 = smm->tx_buffers[thread_index][--n_bufs];
       b0 = vlib_get_buffer (vm, bi0);
       session_tx_fill_buffer (vm, ctx, b0, &n_bufs, peek_data);
diff --git a/src/vnet/tcp/tcp_output.c b/src/vnet/tcp/tcp_output.c
index 4b7915828df..7c113458d54 100644
--- a/src/vnet/tcp/tcp_output.c
+++ b/src/vnet/tcp/tcp_output.c
@@ -1996,8 +1996,8 @@ tcp46_output_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 
       if (n_left_from > 1)
 	{
-	  vlib_prefetch_buffer_header (b[0], STORE);
-	  CLIB_PREFETCH (b[0]->data, 2 * CLIB_CACHE_LINE_BYTES, STORE);
+	  vlib_prefetch_buffer_header (b[1], STORE);
+	  CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, STORE);
 	}
 
       next[0] = TCP_OUTPUT_NEXT_IP_LOOKUP;