Cache a 'has-features' flag on the adjacency for faster access. Reclaim the node_index memeber from the rewrite for space - this is only used for formtting

before:
  ip4-rewrite * * * *  2.66e1  256.00
after:
  ip4-rewrite * * * *  2.40e1  256.00

Change-Id: Ic397150727cad38811564777419ad6bd26b8a3a6
Signed-off-by: Neale Ranns <nranns@wasa-ucs-11.cisco.com>

1 files changed, 23 insertions, 7 deletions

diff --git a/src/vnet/rewrite.h b/src/vnet/rewrite.h
index ce2bce3a3c8..8435a726553 100644
--- a/src/vnet/rewrite.h
+++ b/src/vnet/rewrite.h
@@ -46,14 +46,22 @@
 /* Consider using vector types for speed? */
 typedef uword vnet_rewrite_data_t;
 
+/**
+ * Flags associated with the rewrite/adjacency
+ */
+typedef enum vnet_rewrite_flags_t_
+{
+  /**
+   * This adjacency/interface has output features configured
+   */
+  VNET_REWRITE_HAS_FEATURES = (1 << 0),
+} __attribute__ ((packed)) vnet_rewrite_flags_t;
+
 /* *INDENT-OFF* */
 typedef CLIB_PACKED (struct {
   /* Interface to mark re-written packets with. */
   u32 sw_if_index;
 
-  /* Packet processing node where rewrite happens. */
-  u32 node_index;
-
   /* Next node to feed after packet rewrite is done. */
   u16 next_index;
 
@@ -64,6 +72,11 @@ typedef CLIB_PACKED (struct {
      Used for MTU check after packet rewrite. */
   u16 max_l3_packet_bytes;
 
+  u16 unused1;
+  u8  unused2;
+
+  vnet_rewrite_flags_t flags;
+
   /* When dynamically writing a multicast destination L2 addresss
    * this is the offset within the address to start writing n
    * bytes of the IP mcast address */
@@ -79,6 +92,13 @@ typedef CLIB_PACKED (struct {
 }) vnet_rewrite_header_t;
 /* *INDENT-ON* */
 
+/**
+ * At 16 bytes of rewrite herader we have enought space left for a IPv6
+ * (40 bytes) + LISP-GPE (8 bytes) in the cache line
+ */
+STATIC_ASSERT (sizeof (vnet_rewrite_header_t) <= 16,
+	       "Rewrite header too big");
+
 /*
   Helper macro for declaring rewrite string w/ given max-size.
 
@@ -317,11 +337,7 @@ u8 *vnet_build_rewrite_for_sw_interface (struct vnet_main_t *vnm,
 void vnet_update_adjacency_for_sw_interface (struct vnet_main_t *vnm,
 					     u32 sw_if_index, u32 ai);
 
-/* Parser for unformat header & rewrite string. */
-unformat_function_t unformat_vnet_rewrite;
-
 format_function_t format_vnet_rewrite;
-format_function_t format_vnet_rewrite_header;
 
 serialize_function_t serialize_vnet_rewrite, unserialize_vnet_rewrite;