Merge branch 'tipc-improve-TIPC-unicast-link-throughput'

Tuong Lien says:

====================
tipc: improve TIPC unicast link throughput

The series introduces an algorithm to improve TIPC throughput especially
in terms of packet loss, also tries to reduce packet duplication due to
overactive NACK sending mechanism.

The link failover situation is also covered by the patches.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/msg.h

@@ -117,6 +117,37 @@ struct tipc_msg {
 	__be32 hdr[15];
 };
 
+/* struct tipc_gap_ack - TIPC Gap ACK block
+ * @ack: seqno of the last consecutive packet in link deferdq
+ * @gap: number of gap packets since the last ack
+ *
+ * E.g:
+ *       link deferdq: 1 2 3 4      10 11      13 14 15       20
+ * --> Gap ACK blocks:      <4, 5>,   <11, 1>,      <15, 4>, <20, 0>
+ */
+struct tipc_gap_ack {
+	__be16 ack;
+	__be16 gap;
+};
+
+/* struct tipc_gap_ack_blks
+ * @len: actual length of the record
+ * @gack_cnt: number of Gap ACK blocks in the record
+ * @gacks: array of Gap ACK blocks
+ */
+struct tipc_gap_ack_blks {
+	__be16 len;
+	u8 gack_cnt;
+	u8 reserved;
+	struct tipc_gap_ack gacks[];
+};
+
+#define tipc_gap_ack_blks_sz(n) (sizeof(struct tipc_gap_ack_blks) + \
+				 sizeof(struct tipc_gap_ack) * (n))
+
+#define MAX_GAP_ACK_BLKS	32
+#define MAX_GAP_ACK_BLKS_SZ	tipc_gap_ack_blks_sz(MAX_GAP_ACK_BLKS)
+
 static inline struct tipc_msg *buf_msg(struct sk_buff *skb)
 {
 	return (struct tipc_msg *)skb->data;
@@ -1120,4 +1151,25 @@ static inline void tipc_skb_queue_splice_tail_init(struct sk_buff_head *list,
 	tipc_skb_queue_splice_tail(&tmp, head);
 }
 
+/* __tipc_skb_dequeue() - dequeue the head skb according to expected seqno
+ * @list: list to be dequeued from
+ * @seqno: seqno of the expected msg
+ *
+ * returns skb dequeued from the list if its seqno is less than or equal to
+ * the expected one, otherwise the skb is still hold
+ *
+ * Note: must be used with appropriate locks held only
+ */
+static inline struct sk_buff *__tipc_skb_dequeue(struct sk_buff_head *list,
+						 u16 seqno)
+{
+	struct sk_buff *skb = skb_peek(list);
+
+	if (skb && less_eq(buf_seqno(skb), seqno)) {
+		__skb_unlink(skb, list);
+		return skb;
+	}
+	return NULL;
+}
+
 #endif

net/tipc/node.h

@@ -52,7 +52,8 @@ enum {
 	TIPC_BCAST_RCAST      = (1 << 4),
 	TIPC_NODE_ID128       = (1 << 5),
 	TIPC_LINK_PROTO_SEQNO = (1 << 6),
-	TIPC_MCAST_RBCTL      = (1 << 7)
+	TIPC_MCAST_RBCTL      = (1 << 7),
+	TIPC_GAP_ACK_BLOCK    = (1 << 8)
 };
 
 #define TIPC_NODE_CAPABILITIES (TIPC_SYN_BIT           |  \
@@ -62,7 +63,8 @@ enum {
 				TIPC_BLOCK_FLOWCTL     |   \
 				TIPC_NODE_ID128        |   \
 				TIPC_LINK_PROTO_SEQNO  |   \
-				TIPC_MCAST_RBCTL)
+				TIPC_MCAST_RBCTL       |   \
+				TIPC_GAP_ACK_BLOCK)
 #define INVALID_BEARER_ID -1
 
 void tipc_node_stop(struct net *net);