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Diffstat (limited to 'net/ipv4/tcp_ipv4.c')
-rw-r--r--net/ipv4/tcp_ipv4.c61
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);