From b51e13faf73fcc799a41ed085069f07203d8e7b7 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Tue, 19 Apr 2016 22:50:47 -0700 Subject: tcp: Carry txstamp_ack in tcp_fragment_tstamp When a tcp skb is sliced into two smaller skbs (e.g. in tcp_fragment() and tso_fragment()), it does not carry the txstamp_ack bit to the newly created skb if it is needed. The end result is a timestamping event (SCM_TSTAMP_ACK) will be missing from the sk->sk_error_queue. This patch carries this bit to the new skb2 in tcp_fragment_tstamp(). BPF Output Before: ~~~~~~ BPF Output After: ~~~~~~ <...>-2050 [000] d.s. 100.928763: : ee_data:14599 Packetdrill Script: ~~~~~~ +0 `sysctl -q -w net.ipv4.tcp_min_tso_segs=10` +0 `sysctl -q -w net.ipv4.tcp_no_metrics_save=1` +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 +0 bind(3, ..., ...) = 0 +0 listen(3, 1) = 0 0.100 < S 0:0(0) win 32792 0.100 > S. 0:0(0) ack 1 0.200 < . 1:1(0) ack 1 win 257 0.200 accept(3, ..., ...) = 4 +0 setsockopt(4, SOL_TCP, TCP_NODELAY, [1], 4) = 0 +0 setsockopt(4, SOL_SOCKET, 37, [2688], 4) = 0 0.200 write(4, ..., 14600) = 14600 +0 setsockopt(4, SOL_SOCKET, 37, [2176], 4) = 0 0.200 > . 1:7301(7300) ack 1 0.200 > P. 7301:14601(7300) ack 1 0.300 < . 1:1(0) ack 14601 win 257 0.300 close(4) = 0 0.300 > F. 14601:14601(0) ack 1 0.400 < F. 1:1(0) ack 16062 win 257 0.400 > . 14602:14602(0) ack 2 Signed-off-by: Martin KaFai Lau Cc: Eric Dumazet Cc: Neal Cardwell Cc: Soheil Hassas Yeganeh Cc: Willem de Bruijn Cc: Yuchung Cheng Acked-by: Soheil Hassas Yeganeh Tested-by: Soheil Hassas Yeganeh Acked-by: Willem de Bruijn Signed-off-by: David S. Miller --- net/ipv4/tcp_output.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net') diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 96182a2aabc9..f7c3bc053d27 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1123,6 +1123,8 @@ static void tcp_fragment_tstamp(struct sk_buff *skb, struct sk_buff *skb2) shinfo->tx_flags &= ~tsflags; shinfo2->tx_flags |= tsflags; swap(shinfo->tskey, shinfo2->tskey); + TCP_SKB_CB(skb2)->txstamp_ack = TCP_SKB_CB(skb)->txstamp_ack; + TCP_SKB_CB(skb)->txstamp_ack = 0; } } -- cgit v1.2.3 From 2de8023e7bb288e0bfbe0325a7690d32dc670873 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Tue, 19 Apr 2016 22:50:48 -0700 Subject: tcp: Merge txstamp_ack in tcp_skb_collapse_tstamp When collapsing skbs, txstamp_ack also needs to be merged. Retrans Collapse Test: ~~~~~~ 0.200 accept(3, ..., ...) = 4 +0 setsockopt(4, SOL_TCP, TCP_NODELAY, [1], 4) = 0 0.200 write(4, ..., 730) = 730 +0 setsockopt(4, SOL_SOCKET, 37, [2688], 4) = 0 0.200 write(4, ..., 730) = 730 +0 setsockopt(4, SOL_SOCKET, 37, [2176], 4) = 0 0.200 write(4, ..., 11680) = 11680 0.200 > P. 1:731(730) ack 1 0.200 > P. 731:1461(730) ack 1 0.200 > . 1461:8761(7300) ack 1 0.200 > P. 8761:13141(4380) ack 1 0.300 < . 1:1(0) ack 1 win 257 0.300 < . 1:1(0) ack 1 win 257 0.300 < . 1:1(0) ack 1 win 257 0.300 > P. 1:1461(1460) ack 1 0.400 < . 1:1(0) ack 13141 win 257 BPF Output Before: ~~~~~ BPF Output After: ~~~~~ <...>-2027 [007] d.s. 79.765921: : ee_data:1459 Sacks Collapse Test: ~~~~~ 0.200 accept(3, ..., ...) = 4 +0 setsockopt(4, SOL_TCP, TCP_NODELAY, [1], 4) = 0 0.200 write(4, ..., 1460) = 1460 +0 setsockopt(4, SOL_SOCKET, 37, [2688], 4) = 0 0.200 write(4, ..., 13140) = 13140 +0 setsockopt(4, SOL_SOCKET, 37, [2176], 4) = 0 0.200 > P. 1:1461(1460) ack 1 0.200 > . 1461:8761(7300) ack 1 0.200 > P. 8761:14601(5840) ack 1 0.300 < . 1:1(0) ack 1 win 257 0.300 > P. 1:1461(1460) ack 1 0.400 < . 1:1(0) ack 14601 win 257 BPF Output Before: ~~~~~ BPF Output After: ~~~~~ <...>-2049 [007] d.s. 89.185538: : ee_data:14599 Signed-off-by: Martin KaFai Lau Cc: Eric Dumazet Cc: Neal Cardwell Cc: Soheil Hassas Yeganeh Cc: Willem de Bruijn Cc: Yuchung Cheng Acked-by: Soheil Hassas Yeganeh Tested-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller --- net/ipv4/tcp_output.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net') diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index f7c3bc053d27..a6e4a8353b02 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2454,6 +2454,8 @@ void tcp_skb_collapse_tstamp(struct sk_buff *skb, shinfo->tx_flags |= tsflags; shinfo->tskey = next_shinfo->tskey; + TCP_SKB_CB(skb)->txstamp_ack |= + TCP_SKB_CB(next_skb)->txstamp_ack; } } -- cgit v1.2.3