diff options
| author | Andrey Vagin <avagin@openvz.org> | 2014-08-13 16:03:10 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-10-15 14:05:27 +0400 |
| commit | 485181129a34abde9ebd08c25fba2a55bd62ce52 (patch) | |
| tree | dd29015fb8e11effac0a03a496a6529094ab7f79 /net/ipv4/tcp_output.c | |
| parent | de25adff9abb0f09462d5786232c496c2d7c5f55 (diff) | |
| download | linux-485181129a34abde9ebd08c25fba2a55bd62ce52.tar.xz | |
tcp: don't use timestamp from repaired skb-s to calculate RTT (v2)
[ Upstream commit 9d186cac7ffb1831e9f34cb4a3a8b22abb9dd9d4 ]
We don't know right timestamp for repaired skb-s. Wrong RTT estimations
isn't good, because some congestion modules heavily depends on it.
This patch adds the TCPCB_REPAIRED flag, which is included in
TCPCB_RETRANS.
Thanks to Eric for the advice how to fix this issue.
This patch fixes the warning:
[ 879.562947] WARNING: CPU: 0 PID: 2825 at net/ipv4/tcp_input.c:3078 tcp_ack+0x11f5/0x1380()
[ 879.567253] CPU: 0 PID: 2825 Comm: socket-tcpbuf-l Not tainted 3.16.0-next-20140811 #1
[ 879.567829] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 879.568177] 0000000000000000 00000000c532680c ffff880039643d00 ffffffff817aa2d2
[ 879.568776] 0000000000000000 ffff880039643d38 ffffffff8109afbd ffff880039d6ba80
[ 879.569386] ffff88003a449800 000000002983d6bd 0000000000000000 000000002983d6bc
[ 879.569982] Call Trace:
[ 879.570264] [<ffffffff817aa2d2>] dump_stack+0x4d/0x66
[ 879.570599] [<ffffffff8109afbd>] warn_slowpath_common+0x7d/0xa0
[ 879.570935] [<ffffffff8109b0ea>] warn_slowpath_null+0x1a/0x20
[ 879.571292] [<ffffffff816d0a05>] tcp_ack+0x11f5/0x1380
[ 879.571614] [<ffffffff816d10bd>] tcp_rcv_established+0x1ed/0x710
[ 879.571958] [<ffffffff816dc9da>] tcp_v4_do_rcv+0x10a/0x370
[ 879.572315] [<ffffffff81657459>] release_sock+0x89/0x1d0
[ 879.572642] [<ffffffff816c81a0>] do_tcp_setsockopt.isra.36+0x120/0x860
[ 879.573000] [<ffffffff8110a52e>] ? rcu_read_lock_held+0x6e/0x80
[ 879.573352] [<ffffffff816c8912>] tcp_setsockopt+0x32/0x40
[ 879.573678] [<ffffffff81654ac4>] sock_common_setsockopt+0x14/0x20
[ 879.574031] [<ffffffff816537b0>] SyS_setsockopt+0x80/0xf0
[ 879.574393] [<ffffffff817b40a9>] system_call_fastpath+0x16/0x1b
[ 879.574730] ---[ end trace a17cbc38eb8c5c00 ]---
v2: moving setting of skb->when for repaired skb-s in tcp_write_xmit,
where it's set for other skb-s.
Fixes: 431a91242d8d ("tcp: timestamp SYN+DATA messages")
Fixes: 740b0f1841f6 ("tcp: switch rtt estimations to usec resolution")
Cc: Eric Dumazet <edumazet@google.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/ipv4/tcp_output.c')
| -rw-r--r-- | net/ipv4/tcp_output.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 179b51e6bda3..d87c49bed6dc 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1916,8 +1916,11 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, tso_segs = tcp_init_tso_segs(sk, skb, mss_now); BUG_ON(!tso_segs); - if (unlikely(tp->repair) && tp->repair_queue == TCP_SEND_QUEUE) + if (unlikely(tp->repair) && tp->repair_queue == TCP_SEND_QUEUE) { + /* "when" is used as a start point for the retransmit timer */ + TCP_SKB_CB(skb)->when = tcp_time_stamp; goto repair; /* Skip network transmission */ + } cwnd_quota = tcp_cwnd_test(tp, skb); if (!cwnd_quota) { |