diff options
| author | David S. Miller <davem@davemloft.net> | 2015-02-28 15:10:47 -0500 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-02-28 15:10:47 -0500 |
| commit | f9c7ce18538ed9c099818a9335d7e427d60e97ae (patch) | |
| tree | 5dc19465848a991d8baf2ac3cac3079c92baef5f | |
| parent | 6588af614e7b79294fbcd4a666a7422c0c854e80 (diff) | |
| parent | a0ea700e4095e26a8e291374757dd29519900f18 (diff) | |
Merge branch 'tcp-tso'
Eric Dumazet says:
====================
tcp: tso improvements
This patch serie reworks tcp_tso_should_defer() a bit
to get less bursts, and better ECN behavior.
We also removed tso_deferred field in tcp socket.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/linux/tcp.h | 1 | ||||
| -rw-r--r-- | net/ipv4/tcp_output.c | 29 |
2 files changed, 17 insertions, 13 deletions
diff --git a/include/linux/tcp.h b/include/linux/tcp.h index 1a7adb411647..97dbf16f7d9d 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -236,7 +236,6 @@ struct tcp_sock { u32 lost_out; /* Lost packets */ u32 sacked_out; /* SACK'd packets */ u32 fackets_out; /* FACK'd packets */ - u32 tso_deferred; /* from STCP, retrans queue hinting */ struct sk_buff* lost_skb_hint; diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index a2a796c5536b..8bbd86cd81c8 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1752,20 +1752,23 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len, static bool tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb, bool *is_cwnd_limited, u32 max_segs) { - struct tcp_sock *tp = tcp_sk(sk); const struct inet_connection_sock *icsk = inet_csk(sk); - u32 send_win, cong_win, limit, in_flight; + u32 age, send_win, cong_win, limit, in_flight; + struct tcp_sock *tp = tcp_sk(sk); + struct skb_mstamp now; + struct sk_buff *head; int win_divisor; if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) goto send_now; - if (icsk->icsk_ca_state != TCP_CA_Open) + if (!((1 << icsk->icsk_ca_state) & (TCPF_CA_Open | TCPF_CA_CWR))) goto send_now; - /* Defer for less than two clock ticks. */ - if (tp->tso_deferred && - (((u32)jiffies << 1) >> 1) - (tp->tso_deferred >> 1) > 1) + /* Avoid bursty behavior by allowing defer + * only if the last write was recent. + */ + if ((s32)(tcp_time_stamp - tp->lsndtime) > 0) goto send_now; in_flight = tcp_packets_in_flight(tp); @@ -1807,11 +1810,14 @@ static bool tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb, goto send_now; } - /* Ok, it looks like it is advisable to defer. - * Do not rearm the timer if already set to not break TCP ACK clocking. - */ - if (!tp->tso_deferred) - tp->tso_deferred = 1 | (jiffies << 1); + head = tcp_write_queue_head(sk); + skb_mstamp_get(&now); + age = skb_mstamp_us_delta(&now, &head->skb_mstamp); + /* If next ACK is likely to come too late (half srtt), do not defer */ + if (age < (tp->srtt_us >> 4)) + goto send_now; + + /* Ok, it looks like it is advisable to defer. */ if (cong_win < send_win && cong_win < skb->len) *is_cwnd_limited = true; @@ -1819,7 +1825,6 @@ static bool tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb, return true; send_now: - tp->tso_deferred = 0; return false; } |