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Diffstat (limited to 'net/ipv4/tcp_input.c')
-rw-r--r--net/ipv4/tcp_input.c51
1 files changed, 22 insertions, 29 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 47e08c1b5bc3..188980c58f87 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -426,26 +426,7 @@ static void tcp_grow_window(struct sock *sk, const struct sk_buff *skb)
}
}
-/* 3. Tuning rcvbuf, when connection enters established state. */
-static void tcp_fixup_rcvbuf(struct sock *sk)
-{
- u32 mss = tcp_sk(sk)->advmss;
- int rcvmem;
-
- rcvmem = 2 * SKB_TRUESIZE(mss + MAX_TCP_HEADER) *
- tcp_default_init_rwnd(mss);
-
- /* Dynamic Right Sizing (DRS) has 2 to 3 RTT latency
- * Allow enough cushion so that sender is not limited by our window
- */
- if (sock_net(sk)->ipv4.sysctl_tcp_moderate_rcvbuf)
- rcvmem <<= 2;
-
- if (sk->sk_rcvbuf < rcvmem)
- sk->sk_rcvbuf = min(rcvmem, sock_net(sk)->ipv4.sysctl_tcp_rmem[2]);
-}
-
-/* 4. Try to fixup all. It is made immediately after connection enters
+/* 3. Try to fixup all. It is made immediately after connection enters
* established state.
*/
void tcp_init_buffer_space(struct sock *sk)
@@ -454,12 +435,10 @@ void tcp_init_buffer_space(struct sock *sk)
struct tcp_sock *tp = tcp_sk(sk);
int maxwin;
- if (!(sk->sk_userlocks & SOCK_RCVBUF_LOCK))
- tcp_fixup_rcvbuf(sk);
if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK))
tcp_sndbuf_expand(sk);
- tp->rcvq_space.space = tp->rcv_wnd;
+ tp->rcvq_space.space = min_t(u32, tp->rcv_wnd, TCP_INIT_CWND * tp->advmss);
tcp_mstamp_refresh(tp);
tp->rcvq_space.time = tp->tcp_mstamp;
tp->rcvq_space.seq = tp->copied_seq;
@@ -485,7 +464,7 @@ void tcp_init_buffer_space(struct sock *sk)
tp->snd_cwnd_stamp = tcp_jiffies32;
}
-/* 5. Recalculate window clamp after socket hit its memory bounds. */
+/* 4. Recalculate window clamp after socket hit its memory bounds. */
static void tcp_clamp_window(struct sock *sk)
{
struct tcp_sock *tp = tcp_sk(sk);
@@ -1305,7 +1284,7 @@ static bool tcp_shifted_skb(struct sock *sk, struct sk_buff *prev,
*/
tcp_sacktag_one(sk, state, TCP_SKB_CB(skb)->sacked,
start_seq, end_seq, dup_sack, pcount,
- skb->skb_mstamp);
+ tcp_skb_timestamp_us(skb));
tcp_rate_skb_delivered(sk, skb, state->rate);
if (skb == tp->lost_skb_hint)
@@ -1580,7 +1559,7 @@ static struct sk_buff *tcp_sacktag_walk(struct sk_buff *skb, struct sock *sk,
TCP_SKB_CB(skb)->end_seq,
dup_sack,
tcp_skb_pcount(skb),
- skb->skb_mstamp);
+ tcp_skb_timestamp_us(skb));
tcp_rate_skb_delivered(sk, skb, state->rate);
if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)
list_del_init(&skb->tcp_tsorted_anchor);
@@ -3103,7 +3082,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, u32 prior_fack,
tp->retrans_out -= acked_pcount;
flag |= FLAG_RETRANS_DATA_ACKED;
} else if (!(sacked & TCPCB_SACKED_ACKED)) {
- last_ackt = skb->skb_mstamp;
+ last_ackt = tcp_skb_timestamp_us(skb);
WARN_ON_ONCE(last_ackt == 0);
if (!first_ackt)
first_ackt = last_ackt;
@@ -3121,7 +3100,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, u32 prior_fack,
tp->delivered += acked_pcount;
if (!tcp_skb_spurious_retrans(tp, skb))
tcp_rack_advance(tp, sacked, scb->end_seq,
- skb->skb_mstamp);
+ tcp_skb_timestamp_us(skb));
}
if (sacked & TCPCB_LOST)
tp->lost_out -= acked_pcount;
@@ -3215,7 +3194,8 @@ static int tcp_clean_rtx_queue(struct sock *sk, u32 prior_fack,
tp->lost_cnt_hint -= min(tp->lost_cnt_hint, delta);
}
} else if (skb && rtt_update && sack_rtt_us >= 0 &&
- sack_rtt_us > tcp_stamp_us_delta(tp->tcp_mstamp, skb->skb_mstamp)) {
+ sack_rtt_us > tcp_stamp_us_delta(tp->tcp_mstamp,
+ tcp_skb_timestamp_us(skb))) {
/* Do not re-arm RTO if the sack RTT is measured from data sent
* after when the head was last (re)transmitted. Otherwise the
* timeout may continue to extend in loss recovery.
@@ -4199,6 +4179,17 @@ static void tcp_dsack_extend(struct sock *sk, u32 seq, u32 end_seq)
tcp_sack_extend(tp->duplicate_sack, seq, end_seq);
}
+static void tcp_rcv_spurious_retrans(struct sock *sk, const struct sk_buff *skb)
+{
+ /* When the ACK path fails or drops most ACKs, the sender would
+ * timeout and spuriously retransmit the same segment repeatedly.
+ * The receiver remembers and reflects via DSACKs. Leverage the
+ * DSACK state and change the txhash to re-route speculatively.
+ */
+ if (TCP_SKB_CB(skb)->seq == tcp_sk(sk)->duplicate_sack[0].start_seq)
+ sk_rethink_txhash(sk);
+}
+
static void tcp_send_dupack(struct sock *sk, const struct sk_buff *skb)
{
struct tcp_sock *tp = tcp_sk(sk);
@@ -4211,6 +4202,7 @@ static void tcp_send_dupack(struct sock *sk, const struct sk_buff *skb)
if (tcp_is_sack(tp) && sock_net(sk)->ipv4.sysctl_tcp_dsack) {
u32 end_seq = TCP_SKB_CB(skb)->end_seq;
+ tcp_rcv_spurious_retrans(sk, skb);
if (after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt))
end_seq = tp->rcv_nxt;
tcp_dsack_set(sk, TCP_SKB_CB(skb)->seq, end_seq);
@@ -4755,6 +4747,7 @@ queue_and_out:
}
if (!after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt)) {
+ tcp_rcv_spurious_retrans(sk, skb);
/* A retransmit, 2nd most common case. Force an immediate ack. */
NET_INC_STATS(sock_net(sk), LINUX_MIB_DELAYEDACKLOST);
tcp_dsack_set(sk, TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq);