dpif-netdev: drop swapping

emc_processing() moves all the missed packets towards the beginning of
packet array; matched packets are queued up into flow queues. Since the
remaining of the packet array is not used anymore, don't bother swap
packet pointers to save cycles and simplify logic.

Signed-off-by: Andy Zhou <azhou@ovn.org>
Acked-by: Daniele Di Proietto <diproiettod@vmware.com>

diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index 9d399a0..661d2b0 100644 (file)
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -3285,14 +3285,6 @@ dp_netdev_queue_batches(struct dp_packet *pkt,
     packet_batch_update(batch, pkt, mf);
 }
 
-static inline void
-dp_packet_swap(struct dp_packet **a, struct dp_packet **b)
-{
-    struct dp_packet *tmp = *a;
-    *a = *b;
-    *b = tmp;
-}
-
 /* Try to process all ('cnt') the 'packets' using only the exact match cache
  * 'flow_cache'. If a flow is not found for a packet 'packets[i]', the
  * miniflow is copied into 'keys' and the packet pointer is moved at the
@@ -3333,10 +3325,9 @@ emc_processing(struct dp_netdev_pmd_thread *pmd, struct dp_packet **packets,
             dp_netdev_queue_batches(packets[i], flow, &key.mf, batches,
                                     n_batches);
         } else {
-            if (i != n_missed) {
-                dp_packet_swap(&packets[i], &packets[n_missed]);
-            }
-
+            /* Exact match cache missed. Group missed packets together at
+             * the beginning of the 'packets' array.  */
+            packets[n_missed] = packets[i];
             keys[n_missed++] = key;
         }
     }