1 files changed, 1 insertions, 60 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 3a19ea28339f..a68eb4577d36 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1541,61 +1541,6 @@ void tcp_v4_early_demux(struct sk_buff *skb)
         }
 }
 
-/* Packet is added to VJ-style prequeue for processing in process
- * context, if a reader task is waiting. Apparently, this exciting
- * idea (VJ's mail "Re: query about TCP header on tcp-ip" of 07 Sep 93)
- * failed somewhere. Latency? Burstiness? Well, at least now we will
- * see, why it failed. 8)8)                               --ANK
- *
- */
-bool tcp_prequeue(struct sock *sk, struct sk_buff *skb)
-{
-        struct tcp_sock *tp = tcp_sk(sk);
-
-        if (sysctl_tcp_low_latency || !tp->ucopy.task)
-                return false;
-
-        if (skb->len <= tcp_hdrlen(skb) &&
-            skb_queue_len(&tp->ucopy.prequeue) == 0)
-                return false;
-
-        /* Before escaping RCU protected region, we need to take care of skb
-         * dst. Prequeue is only enabled for established sockets.
-         * For such sockets, we might need the skb dst only to set sk->sk_rx_dst
-         * Instead of doing full sk_rx_dst validity here, let's perform
-         * an optimistic check.
-         */
-        if (likely(sk->sk_rx_dst))
-                skb_dst_drop(skb);
-        else
-                skb_dst_force_safe(skb);
-
-        __skb_queue_tail(&tp->ucopy.prequeue, skb);
-        tp->ucopy.memory += skb->truesize;
-        if (skb_queue_len(&tp->ucopy.prequeue) >= 32 ||
-            tp->ucopy.memory + atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf) {
-                struct sk_buff *skb1;
-
-                BUG_ON(sock_owned_by_user(sk));
-                __NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPPREQUEUEDROPPED,
-                                skb_queue_len(&tp->ucopy.prequeue));
-
-                while ((skb1 = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
-                        sk_backlog_rcv(sk, skb1);
-
-                tp->ucopy.memory = 0;
-        } else if (skb_queue_len(&tp->ucopy.prequeue) == 1) {
-                wake_up_interruptible_sync_poll(sk_sleep(sk),
-                                           POLLIN | POLLRDNORM | POLLRDBAND);
-                if (!inet_csk_ack_scheduled(sk))
-                        inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
-                                                  (3 * tcp_rto_min(sk)) / 4,
-                                                  TCP_RTO_MAX);
-        }
-        return true;
-}
-EXPORT_SYMBOL(tcp_prequeue);
-
 bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb)
 {
         u32 limit = sk->sk_rcvbuf + sk->sk_sndbuf;
@@ -1770,8 +1715,7 @@ process:
         tcp_segs_in(tcp_sk(sk), skb);
         ret = 0;
         if (!sock_owned_by_user(sk)) {
-                if (!tcp_prequeue(sk, skb))
-                        ret = tcp_v4_do_rcv(sk, skb);
+                ret = tcp_v4_do_rcv(sk, skb);
         } else if (tcp_add_backlog(sk, skb)) {
                 goto discard_and_relse;
         }
@@ -1936,9 +1880,6 @@ void tcp_v4_destroy_sock(struct sock *sk)
         }
 #endif
 
-        /* Clean prequeue, it must be empty really */
-        __skb_queue_purge(&tp->ucopy.prequeue);
-
         /* Clean up a referenced TCP bind bucket. */
         if (inet_csk(sk)->icsk_bind_hash)
                 inet_put_port(sk);