Move pkt replication counter to the opaque2 cache line

Change-Id: I5e6edfd03ab41949be2c768dfe68aa824bbc1f38
Signed-off-by: Dave Barach <dave@barachs.net>

3 files changed, 16 insertions, 14 deletions

diff --git a/vlib/vlib/buffer.c b/vlib/vlib/buffer.c
index b7ae0a6fa34..f727e67a55a 100644
--- a/vlib/vlib/buffer.c
+++ b/vlib/vlib/buffer.c
@@ -901,8 +901,8 @@ vlib_buffer_free_inline (vlib_main_t * vm,
       b0 = vlib_get_buffer (vm, bi0);
       b1 = vlib_get_buffer (vm, bi1);
 
-      free0 = b0->clone_count == 0;
-      free1 = b1->clone_count == 0;
+      free0 = (b0->flags & VLIB_BUFFER_RECYCLE) == 0;
+      free1 = (b1->flags & VLIB_BUFFER_RECYCLE) == 0;
 
       /* Must be before init which will over-write buffer flags. */
       if (follow_buffer_next)
@@ -986,7 +986,7 @@ vlib_buffer_free_inline (vlib_main_t * vm,
 
       b0 = vlib_get_buffer (vm, bi0);
 
-      free0 = b0->clone_count == 0;
+      free0 = (b0->flags & VLIB_BUFFER_RECYCLE) == 0;
 
       /* Must be before init which will over-write buffer flags. */
       if (follow_buffer_next)
diff --git a/vlib/vlib/buffer.h b/vlib/vlib/buffer.h
index 52749572509..bc799bc6223 100644
--- a/vlib/vlib/buffer.h
+++ b/vlib/vlib/buffer.h
@@ -86,6 +86,7 @@ typedef struct {
                 <br> VLIB_BUFFER_NEXT_PRESENT: this is a multi-chunk buffer.
                 <br> VLIB_BUFFER_TOTAL_LENGTH_VALID: as it says
                 <br> VLIB_BUFFER_REPL_FAIL: packet replication failure
+                <br> VLIB_BUFFER_RECYCLE: as it says
                 <br> VLIB_BUFFER_FLAG_USER(n): user-defined bit N
              */
 #define VLIB_BUFFER_IS_TRACED (1 << 0)
@@ -94,6 +95,7 @@ typedef struct {
 #define VLIB_BUFFER_IS_RECYCLED (1 << 2) 
 #define VLIB_BUFFER_TOTAL_LENGTH_VALID (1 << 3)
 #define VLIB_BUFFER_REPL_FAIL (1 << 4) 
+#define VLIB_BUFFER_RECYCLE (1 << 5)
 
   /* User defined buffer flags. */
 #define LOG2_VLIB_BUFFER_FLAG_USER(n) (32 - (n))
@@ -112,14 +114,6 @@ typedef struct {
                         Only valid if VLIB_BUFFER_NEXT_PRESENT flag is set. 
                      */
 
-  u32 clone_count; /**< Specifies whether this buffer should be 
-                      reinitialized when freed. It will be reinitialized 
-                      if the value is 0. This field can be used
-                      as a counter or for other state during packet 
-                      replication. The buffer free function does not 
-                      modify this value. 
-                   */
-
   vlib_error_t error;   /**< Error code for buffers to be enqueued 
                            to error handler. 
                         */
@@ -127,6 +121,11 @@ typedef struct {
                                visit enabled feature nodes
                             */
 
+  u32 dont_waste_me; /**< Available space in the (precious)
+                        first 32 octets of buffer metadata
+                        Before allocating any of it, discussion required!
+                     */
+
   u32 opaque[8]; /**< Opaque data used by sub-graphs for their own purposes. 
                     See .../vnet/vnet/buffer.h
                  */
@@ -135,7 +134,8 @@ typedef struct {
   u32 trace_index; /**< Specifies index into trace buffer 
                       if VLIB_PACKET_IS_TRACED flag is set. 
                    */
-  u32 opaque2[15];  /**< More opaque data, currently unused */
+  u32 recycle_count; /**< Used by L2 path recycle code */
+  u32 opaque2[14];  /**< More opaque data, currently unused */
 
   /***** end of second cache line */
   CLIB_CACHE_LINE_ALIGN_MARK(cacheline2);
diff --git a/vlib/vlib/dpdk_buffer.c b/vlib/vlib/dpdk_buffer.c
index ce0f32649aa..c0094938479 100644
--- a/vlib/vlib/dpdk_buffer.c
+++ b/vlib/vlib/dpdk_buffer.c
@@ -708,7 +708,9 @@ vlib_buffer_free_inline (vlib_main_t * vm,
         {
           int j;
           
-          add_buffer_to_free_list (vm, fl, buffers[i], b->clone_count == 0);
+          add_buffer_to_free_list 
+              (vm, fl, buffers[i], 
+               (b->flags & VLIB_BUFFER_RECYCLE) == 0);
           
           for (j = 0; j < vec_len (bm->announce_list); j++)
             {
@@ -721,7 +723,7 @@ vlib_buffer_free_inline (vlib_main_t * vm,
         }
       else
         {
-	  if (PREDICT_TRUE (b->clone_count == 0))
+          if (PREDICT_TRUE ((b->flags & VLIB_BUFFER_RECYCLE) == 0))
 	    {
 	      mb = rte_mbuf_from_vlib_buffer(b);
 	      ASSERT(rte_mbuf_refcnt_read(mb) == 1);