[ovs-dev] [PATCH 2/7] dpif-netdev: retrieve flow directly from the flow mark

[Yuanhan Liu]

So that we could skip the heavy emc processing. A simple PHY-PHY
forwarding testing shows almost 80% performance improvement.

Signed-off-by: Yuanhan Liu <yliu at fridaylinux.org>
Signed-off-by: Finn Christensen <fc at napatech.com>
---
 lib/dp-packet.h   | 13 +++++++++++++
 lib/dpif-netdev.c | 17 +++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/lib/dp-packet.h b/lib/dp-packet.h
index bb3f9db..7ecabcc 100644
--- a/lib/dp-packet.h
+++ b/lib/dp-packet.h
@@ -687,6 +687,19 @@ reset_dp_packet_checksum_ol_flags(struct dp_packet *p)
 #define reset_dp_packet_checksum_ol_flags(arg)
 #endif
 
+static inline bool
+dp_packet_has_flow_mark(struct dp_packet *p OVS_UNUSED,
+                        uint32_t *mark OVS_UNUSED)
+{
+#ifdef DPDK_NETDEV
+    if (p->mbuf.ol_flags & PKT_RX_FDIR_ID) {
+        *mark = p->mbuf.hash.fdir.hi;
+        return true;
+    }
+#endif
+    return false;
+}
+
 enum { NETDEV_MAX_BURST = 32 }; /* Maximum number packets in a batch. */
 
 struct dp_packet_batch {
diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index aaeb7c2..b5f157e 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -4765,6 +4765,7 @@ emc_processing(struct dp_netdev_pmd_thread *pmd,
 
     DP_PACKET_BATCH_REFILL_FOR_EACH (i, size, packet, packets_) {
         struct dp_netdev_flow *flow;
+        uint32_t flow_mark;
 
         if (OVS_UNLIKELY(dp_packet_size(packet) < ETH_HEADER_LEN)) {
             dp_packet_delete(packet);
@@ -4772,6 +4773,22 @@ emc_processing(struct dp_netdev_pmd_thread *pmd,
             continue;
         }
 
+        if (dp_packet_has_flow_mark(packet, &flow_mark)) {
+            flow = dp_netdev_pmd_find_flow_by_mark(pmd, flow_mark);
+            if (flow) {
+                /* FIXME: this fake mf won't update tcp_flags */
+                struct miniflow fake_mf = {
+                    FLOWMAP_EMPTY_INITIALIZER,
+                    miniflow_values(&fake_mf),
+                    miniflow_values(&fake_mf) + FLOW_U64S
+                };
+
+                dp_netdev_queue_batches(packet, flow, &fake_mf, batches,
+                                        n_batches);
+                continue;
+            }
+        }
+
         if (i != size - 1) {
             struct dp_packet **packets = packets_->packets;
             /* Prefetch next packet data and metadata. */
-- 
2.7.4