diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 8cd02c0..a5934c4 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4108,7 +4108,7 @@
 	/* It _is_ possible, that we have something out-of-order _after_ FIN.
 	 * Probably, we should reset in this case. For now drop them.
 	 */
-	__skb_queue_purge(&tp->out_of_order_queue);
+	skb_rbtree_purge(&tp->out_of_order_queue);
 	if (tcp_is_sack(tp))
 		tcp_sack_reset(&tp->rx_opt);
 	sk_mem_reclaim(sk);
@@ -4268,7 +4268,7 @@
 	int this_sack;
 
 	/* Empty ofo queue, hence, all the SACKs are eaten. Clear. */
-	if (skb_queue_empty(&tp->out_of_order_queue)) {
+	if (RB_EMPTY_ROOT(&tp->out_of_order_queue)) {
 		tp->rx_opt.num_sacks = 0;
 		return;
 	}
@@ -4344,10 +4344,13 @@
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	__u32 dsack_high = tp->rcv_nxt;
+	bool fin, fragstolen, eaten;
 	struct sk_buff *skb, *tail;
-	bool fragstolen, eaten;
+	struct rb_node *p;
 
-	while ((skb = skb_peek(&tp->out_of_order_queue)) != NULL) {
+	p = rb_first(&tp->out_of_order_queue);
+	while (p) {
+		skb = rb_entry(p, struct sk_buff, rbnode);
 		if (after(TCP_SKB_CB(skb)->seq, tp->rcv_nxt))
 			break;
 
@@ -4357,9 +4360,10 @@
 				dsack_high = TCP_SKB_CB(skb)->end_seq;
 			tcp_dsack_extend(sk, TCP_SKB_CB(skb)->seq, dsack);
 		}
+		p = rb_next(p);
+		rb_erase(&skb->rbnode, &tp->out_of_order_queue);
 
-		__skb_unlink(skb, &tp->out_of_order_queue);
-		if (!after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt)) {
+		if (unlikely(!after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt))) {
 			SOCK_DEBUG(sk, "ofo packet was already received\n");
 			tcp_drop(sk, skb);
 			continue;
@@ -4371,12 +4375,19 @@
 		tail = skb_peek_tail(&sk->sk_receive_queue);
 		eaten = tail && tcp_try_coalesce(sk, tail, skb, &fragstolen);
 		tcp_rcv_nxt_update(tp, TCP_SKB_CB(skb)->end_seq);
+		fin = TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN;
 		if (!eaten)
 			__skb_queue_tail(&sk->sk_receive_queue, skb);
-		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
-			tcp_fin(sk);
-		if (eaten)
+		else
 			kfree_skb_partial(skb, fragstolen);
+
+		if (unlikely(fin)) {
+			tcp_fin(sk);
+			/* tcp_fin() purges tp->out_of_order_queue,
+			 * so we must end this loop right now.
+			 */
+			break;
+		}
 	}
 }
 
@@ -4403,8 +4414,10 @@
 static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
+	struct rb_node **p, *q, *parent;
 	struct sk_buff *skb1;
 	u32 seq, end_seq;
+	bool fragstolen;
 
 	tcp_ecn_check_ce(tp, skb);
 
@@ -4419,88 +4432,85 @@
 	inet_csk_schedule_ack(sk);
 
 	NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPOFOQUEUE);
+	seq = TCP_SKB_CB(skb)->seq;
+	end_seq = TCP_SKB_CB(skb)->end_seq;
 	SOCK_DEBUG(sk, "out of order segment: rcv_next %X seq %X - %X\n",
-		   tp->rcv_nxt, TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq);
+		   tp->rcv_nxt, seq, end_seq);
 
-	skb1 = skb_peek_tail(&tp->out_of_order_queue);
-	if (!skb1) {
+	p = &tp->out_of_order_queue.rb_node;
+	if (RB_EMPTY_ROOT(&tp->out_of_order_queue)) {
 		/* Initial out of order segment, build 1 SACK. */
 		if (tcp_is_sack(tp)) {
 			tp->rx_opt.num_sacks = 1;
-			tp->selective_acks[0].start_seq = TCP_SKB_CB(skb)->seq;
-			tp->selective_acks[0].end_seq =
-						TCP_SKB_CB(skb)->end_seq;
+			tp->selective_acks[0].start_seq = seq;
+			tp->selective_acks[0].end_seq = end_seq;
 		}
-		__skb_queue_head(&tp->out_of_order_queue, skb);
+		rb_link_node(&skb->rbnode, NULL, p);
+		rb_insert_color(&skb->rbnode, &tp->out_of_order_queue);
+		tp->ooo_last_skb = skb;
 		goto end;
 	}
 
-	seq = TCP_SKB_CB(skb)->seq;
-	end_seq = TCP_SKB_CB(skb)->end_seq;
-
-	if (seq == TCP_SKB_CB(skb1)->end_seq) {
-		bool fragstolen;
-
-		if (!tcp_try_coalesce(sk, skb1, skb, &fragstolen)) {
-			__skb_queue_after(&tp->out_of_order_queue, skb1, skb);
-		} else {
-			tcp_grow_window(sk, skb);
-			kfree_skb_partial(skb, fragstolen);
-			skb = NULL;
-		}
-
-		if (!tp->rx_opt.num_sacks ||
-		    tp->selective_acks[0].end_seq != seq)
-			goto add_sack;
-
-		/* Common case: data arrive in order after hole. */
-		tp->selective_acks[0].end_seq = end_seq;
-		goto end;
+	/* In the typical case, we are adding an skb to the end of the list.
+	 * Use of ooo_last_skb avoids the O(Log(N)) rbtree lookup.
+	 */
+	if (tcp_try_coalesce(sk, tp->ooo_last_skb, skb, &fragstolen)) {
+coalesce_done:
+		tcp_grow_window(sk, skb);
+		kfree_skb_partial(skb, fragstolen);
+		skb = NULL;
+		goto add_sack;
 	}
 
-	/* Find place to insert this segment. */
-	while (1) {
-		if (!after(TCP_SKB_CB(skb1)->seq, seq))
-			break;
-		if (skb_queue_is_first(&tp->out_of_order_queue, skb1)) {
-			skb1 = NULL;
-			break;
+	/* Find place to insert this segment. Handle overlaps on the way. */
+	parent = NULL;
+	while (*p) {
+		parent = *p;
+		skb1 = rb_entry(parent, struct sk_buff, rbnode);
+		if (before(seq, TCP_SKB_CB(skb1)->seq)) {
+			p = &parent->rb_left;
+			continue;
 		}
-		skb1 = skb_queue_prev(&tp->out_of_order_queue, skb1);
+		if (before(seq, TCP_SKB_CB(skb1)->end_seq)) {
+			if (!after(end_seq, TCP_SKB_CB(skb1)->end_seq)) {
+				/* All the bits are present. Drop. */
+				NET_INC_STATS(sock_net(sk),
+					      LINUX_MIB_TCPOFOMERGE);
+				__kfree_skb(skb);
+				skb = NULL;
+				tcp_dsack_set(sk, seq, end_seq);
+				goto add_sack;
+			}
+			if (after(seq, TCP_SKB_CB(skb1)->seq)) {
+				/* Partial overlap. */
+				tcp_dsack_set(sk, seq, TCP_SKB_CB(skb1)->end_seq);
+			} else {
+				/* skb's seq == skb1's seq and skb covers skb1.
+				 * Replace skb1 with skb.
+				 */
+				rb_replace_node(&skb1->rbnode, &skb->rbnode,
+						&tp->out_of_order_queue);
+				tcp_dsack_extend(sk,
+						 TCP_SKB_CB(skb1)->seq,
+						 TCP_SKB_CB(skb1)->end_seq);
+				NET_INC_STATS(sock_net(sk),
+					      LINUX_MIB_TCPOFOMERGE);
+				__kfree_skb(skb1);
+				goto add_sack;
+			}
+		} else if (tcp_try_coalesce(sk, skb1, skb, &fragstolen)) {
+			goto coalesce_done;
+		}
+		p = &parent->rb_right;
 	}
 
-	/* Do skb overlap to previous one? */
-	if (skb1 && before(seq, TCP_SKB_CB(skb1)->end_seq)) {
-		if (!after(end_seq, TCP_SKB_CB(skb1)->end_seq)) {
-			/* All the bits are present. Drop. */
-			NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPOFOMERGE);
-			tcp_drop(sk, skb);
-			skb = NULL;
-			tcp_dsack_set(sk, seq, end_seq);
-			goto add_sack;
-		}
-		if (after(seq, TCP_SKB_CB(skb1)->seq)) {
-			/* Partial overlap. */
-			tcp_dsack_set(sk, seq,
-				      TCP_SKB_CB(skb1)->end_seq);
-		} else {
-			if (skb_queue_is_first(&tp->out_of_order_queue,
-					       skb1))
-				skb1 = NULL;
-			else
-				skb1 = skb_queue_prev(
-					&tp->out_of_order_queue,
-					skb1);
-		}
-	}
-	if (!skb1)
-		__skb_queue_head(&tp->out_of_order_queue, skb);
-	else
-		__skb_queue_after(&tp->out_of_order_queue, skb1, skb);
+	/* Insert segment into RB tree. */
+	rb_link_node(&skb->rbnode, parent, p);
+	rb_insert_color(&skb->rbnode, &tp->out_of_order_queue);
 
-	/* And clean segments covered by new one as whole. */
-	while (!skb_queue_is_last(&tp->out_of_order_queue, skb)) {
-		skb1 = skb_queue_next(&tp->out_of_order_queue, skb);
+	/* Remove other segments covered by skb. */
+	while ((q = rb_next(&skb->rbnode)) != NULL) {
+		skb1 = rb_entry(q, struct sk_buff, rbnode);
 
 		if (!after(end_seq, TCP_SKB_CB(skb1)->seq))
 			break;
@@ -4509,12 +4519,15 @@
 					 end_seq);
 			break;
 		}
-		__skb_unlink(skb1, &tp->out_of_order_queue);
+		rb_erase(&skb1->rbnode, &tp->out_of_order_queue);
 		tcp_dsack_extend(sk, TCP_SKB_CB(skb1)->seq,
 				 TCP_SKB_CB(skb1)->end_seq);
 		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPOFOMERGE);
 		tcp_drop(sk, skb1);
 	}
+	/* If there is no skb after us, we are the last_skb ! */
+	if (!q)
+		tp->ooo_last_skb = skb;
 
 add_sack:
 	if (tcp_is_sack(tp))
@@ -4651,13 +4664,13 @@
 		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
 			tcp_fin(sk);
 
-		if (!skb_queue_empty(&tp->out_of_order_queue)) {
+		if (!RB_EMPTY_ROOT(&tp->out_of_order_queue)) {
 			tcp_ofo_queue(sk);
 
 			/* RFC2581. 4.2. SHOULD send immediate ACK, when
 			 * gap in queue is filled.
 			 */
-			if (skb_queue_empty(&tp->out_of_order_queue))
+			if (RB_EMPTY_ROOT(&tp->out_of_order_queue))
 				inet_csk(sk)->icsk_ack.pingpong = 0;
 		}
 
@@ -4711,48 +4724,76 @@
 	tcp_data_queue_ofo(sk, skb);
 }
 
-static struct sk_buff *tcp_collapse_one(struct sock *sk, struct sk_buff *skb,
-					struct sk_buff_head *list)
+static struct sk_buff *tcp_skb_next(struct sk_buff *skb, struct sk_buff_head *list)
 {
-	struct sk_buff *next = NULL;
+	if (list)
+		return !skb_queue_is_last(list, skb) ? skb->next : NULL;
 
-	if (!skb_queue_is_last(list, skb))
-		next = skb_queue_next(list, skb);
+	return rb_entry_safe(rb_next(&skb->rbnode), struct sk_buff, rbnode);
+}
 
-	__skb_unlink(skb, list);
+static struct sk_buff *tcp_collapse_one(struct sock *sk, struct sk_buff *skb,
+					struct sk_buff_head *list,
+					struct rb_root *root)
+{
+	struct sk_buff *next = tcp_skb_next(skb, list);
+
+	if (list)
+		__skb_unlink(skb, list);
+	else
+		rb_erase(&skb->rbnode, root);
+
 	__kfree_skb(skb);
 	NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPRCVCOLLAPSED);
 
 	return next;
 }
 
+/* Insert skb into rb tree, ordered by TCP_SKB_CB(skb)->seq */
+static void tcp_rbtree_insert(struct rb_root *root, struct sk_buff *skb)
+{
+	struct rb_node **p = &root->rb_node;
+	struct rb_node *parent = NULL;
+	struct sk_buff *skb1;
+
+	while (*p) {
+		parent = *p;
+		skb1 = rb_entry(parent, struct sk_buff, rbnode);
+		if (before(TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb1)->seq))
+			p = &parent->rb_left;
+		else
+			p = &parent->rb_right;
+	}
+	rb_link_node(&skb->rbnode, parent, p);
+	rb_insert_color(&skb->rbnode, root);
+}
+
 /* Collapse contiguous sequence of skbs head..tail with
  * sequence numbers start..end.
  *
- * If tail is NULL, this means until the end of the list.
+ * If tail is NULL, this means until the end of the queue.
  *
  * Segments with FIN/SYN are not collapsed (only because this
  * simplifies code)
  */
 static void
-tcp_collapse(struct sock *sk, struct sk_buff_head *list,
-	     struct sk_buff *head, struct sk_buff *tail,
-	     u32 start, u32 end)
+tcp_collapse(struct sock *sk, struct sk_buff_head *list, struct rb_root *root,
+	     struct sk_buff *head, struct sk_buff *tail, u32 start, u32 end)
 {
-	struct sk_buff *skb, *n;
+	struct sk_buff *skb = head, *n;
+	struct sk_buff_head tmp;
 	bool end_of_skbs;
 
 	/* First, check that queue is collapsible and find
-	 * the point where collapsing can be useful. */
-	skb = head;
+	 * the point where collapsing can be useful.
+	 */
 restart:
-	end_of_skbs = true;
-	skb_queue_walk_from_safe(list, skb, n) {
-		if (skb == tail)
-			break;
+	for (end_of_skbs = true; skb != NULL && skb != tail; skb = n) {
+		n = tcp_skb_next(skb, list);
+
 		/* No new bits? It is possible on ofo queue. */
 		if (!before(start, TCP_SKB_CB(skb)->end_seq)) {
-			skb = tcp_collapse_one(sk, skb, list);
+			skb = tcp_collapse_one(sk, skb, list, root);
 			if (!skb)
 				break;
 			goto restart;
@@ -4770,13 +4811,10 @@
 			break;
 		}
 
-		if (!skb_queue_is_last(list, skb)) {
-			struct sk_buff *next = skb_queue_next(list, skb);
-			if (next != tail &&
-			    TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(next)->seq) {
-				end_of_skbs = false;
-				break;
-			}
+		if (n && n != tail &&
+		    TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(n)->seq) {
+			end_of_skbs = false;
+			break;
 		}
 
 		/* Decided to skip this, advance start seq. */
@@ -4786,17 +4824,22 @@
 	    (TCP_SKB_CB(skb)->tcp_flags & (TCPHDR_SYN | TCPHDR_FIN)))
 		return;
 
+	__skb_queue_head_init(&tmp);
+
 	while (before(start, end)) {
 		int copy = min_t(int, SKB_MAX_ORDER(0, 0), end - start);
 		struct sk_buff *nskb;
 
 		nskb = alloc_skb(copy, GFP_ATOMIC);
 		if (!nskb)
-			return;
+			break;
 
 		memcpy(nskb->cb, skb->cb, sizeof(skb->cb));
 		TCP_SKB_CB(nskb)->seq = TCP_SKB_CB(nskb)->end_seq = start;
-		__skb_queue_before(list, skb, nskb);
+		if (list)
+			__skb_queue_before(list, skb, nskb);
+		else
+			__skb_queue_tail(&tmp, nskb); /* defer rbtree insertion */
 		skb_set_owner_r(nskb, sk);
 
 		/* Copy data, releasing collapsed skbs. */
@@ -4814,14 +4857,17 @@
 				start += size;
 			}
 			if (!before(start, TCP_SKB_CB(skb)->end_seq)) {
-				skb = tcp_collapse_one(sk, skb, list);
+				skb = tcp_collapse_one(sk, skb, list, root);
 				if (!skb ||
 				    skb == tail ||
 				    (TCP_SKB_CB(skb)->tcp_flags & (TCPHDR_SYN | TCPHDR_FIN)))
-					return;
+					goto end;
 			}
 		}
 	}
+end:
+	skb_queue_walk_safe(&tmp, skb, n)
+		tcp_rbtree_insert(root, skb);
 }
 
 /* Collapse ofo queue. Algorithm: select contiguous sequence of skbs
@@ -4830,43 +4876,43 @@
 static void tcp_collapse_ofo_queue(struct sock *sk)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
-	struct sk_buff *skb = skb_peek(&tp->out_of_order_queue);
-	struct sk_buff *head;
+	struct sk_buff *skb, *head;
+	struct rb_node *p;
 	u32 start, end;
 
-	if (!skb)
+	p = rb_first(&tp->out_of_order_queue);
+	skb = rb_entry_safe(p, struct sk_buff, rbnode);
+new_range:
+	if (!skb) {
+		p = rb_last(&tp->out_of_order_queue);
+		/* Note: This is possible p is NULL here. We do not
+		 * use rb_entry_safe(), as ooo_last_skb is valid only
+		 * if rbtree is not empty.
+		 */
+		tp->ooo_last_skb = rb_entry(p, struct sk_buff, rbnode);
 		return;
-
+	}
 	start = TCP_SKB_CB(skb)->seq;
 	end = TCP_SKB_CB(skb)->end_seq;
-	head = skb;
 
-	for (;;) {
-		struct sk_buff *next = NULL;
+	for (head = skb;;) {
+		skb = tcp_skb_next(skb, NULL);
 
-		if (!skb_queue_is_last(&tp->out_of_order_queue, skb))
-			next = skb_queue_next(&tp->out_of_order_queue, skb);
-		skb = next;
-
-		/* Segment is terminated when we see gap or when
-		 * we are at the end of all the queue. */
+		/* Range is terminated when we see a gap or when
+		 * we are at the queue end.
+		 */
 		if (!skb ||
 		    after(TCP_SKB_CB(skb)->seq, end) ||
 		    before(TCP_SKB_CB(skb)->end_seq, start)) {
-			tcp_collapse(sk, &tp->out_of_order_queue,
+			tcp_collapse(sk, NULL, &tp->out_of_order_queue,
 				     head, skb, start, end);
-			head = skb;
-			if (!skb)
-				break;
-			/* Start new segment */
-			start = TCP_SKB_CB(skb)->seq;
-			end = TCP_SKB_CB(skb)->end_seq;
-		} else {
-			if (before(TCP_SKB_CB(skb)->seq, start))
-				start = TCP_SKB_CB(skb)->seq;
-			if (after(TCP_SKB_CB(skb)->end_seq, end))
-				end = TCP_SKB_CB(skb)->end_seq;
+			goto new_range;
 		}
+
+		if (unlikely(before(TCP_SKB_CB(skb)->seq, start)))
+			start = TCP_SKB_CB(skb)->seq;
+		if (after(TCP_SKB_CB(skb)->end_seq, end))
+			end = TCP_SKB_CB(skb)->end_seq;
 	}
 }
 
@@ -4883,20 +4929,24 @@
 static bool tcp_prune_ofo_queue(struct sock *sk)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
-	struct sk_buff *skb;
+	struct rb_node *node, *prev;
 
-	if (skb_queue_empty(&tp->out_of_order_queue))
+	if (RB_EMPTY_ROOT(&tp->out_of_order_queue))
 		return false;
 
 	NET_INC_STATS(sock_net(sk), LINUX_MIB_OFOPRUNED);
-
-	while ((skb = __skb_dequeue_tail(&tp->out_of_order_queue)) != NULL) {
-		tcp_drop(sk, skb);
+	node = &tp->ooo_last_skb->rbnode;
+	do {
+		prev = rb_prev(node);
+		rb_erase(node, &tp->out_of_order_queue);
+		tcp_drop(sk, rb_entry(node, struct sk_buff, rbnode));
 		sk_mem_reclaim(sk);
 		if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
 		    !tcp_under_memory_pressure(sk))
 			break;
-	}
+		node = prev;
+	} while (node);
+	tp->ooo_last_skb = rb_entry(prev, struct sk_buff, rbnode);
 
 	/* Reset SACK state.  A conforming SACK implementation will
 	 * do the same at a timeout based retransmit.  When a connection
@@ -4930,7 +4980,7 @@
 
 	tcp_collapse_ofo_queue(sk);
 	if (!skb_queue_empty(&sk->sk_receive_queue))
-		tcp_collapse(sk, &sk->sk_receive_queue,
+		tcp_collapse(sk, &sk->sk_receive_queue, NULL,
 			     skb_peek(&sk->sk_receive_queue),
 			     NULL,
 			     tp->copied_seq, tp->rcv_nxt);
@@ -5035,7 +5085,7 @@
 	    /* We ACK each frame or... */
 	    tcp_in_quickack_mode(sk) ||
 	    /* We have out of order data. */
-	    (ofo_possible && skb_peek(&tp->out_of_order_queue))) {
+	    (ofo_possible && !RB_EMPTY_ROOT(&tp->out_of_order_queue))) {
 		/* Then ack it now */
 		tcp_send_ack(sk);
 	} else {