From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrey Vagin Subject: [PATCH] [RFC] tcp: add ability to set a timestamp offset (v2) Date: Wed, 23 Jan 2013 19:01:52 +0400 Message-ID: <1358953314-12979-1-git-send-email-avagin@openvz.org> Cc: criu@openvz.org, linux-kernel@vger.kernel.org, Andrey Vagin , "David S. Miller" , Alexey Kuznetsov , James Morris , Hideaki YOSHIFUJI , Patrick McHardy , Eric Dumazet , Yuchung Cheng , Neal Cardwell , Pavel Emelyanov , Dave Jones , Michael Kerrisk To: netdev@vger.kernel.org Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org If a TCP socket will get live-migrated from one box to another the timestamps (which are typically ON) will get screwed up -- the new kernel will generate TS values that has nothing to do with what they were on dump. The solution is to yet again fix the kernel and put a "timestamp offset" on a socket. v2: We can't adjust tcp_time_stamp only for output packets, because echoed timestamp values will also no longer have a meaningful relationship to tcp_time_stamp. That violates assumptions made in several places in the code, which assumes that we can compare echoed timestamp values to tcp_time_stamp; //Neal Cardwell This version is a "bit more" radical. It makes tcp_time_stamp dependent on tcp_sock. The idea of this patch is in the next two lines: -#define tcp_time_stamp ((__u32)(jiffies)) +#define tcp_time_stamp(tp) ((__u32)(jiffies) + tp->tsoffset) Cc: "David S. Miller" Cc: Alexey Kuznetsov Cc: James Morris Cc: Hideaki YOSHIFUJI Cc: Patrick McHardy Cc: Eric Dumazet Cc: Yuchung Cheng Cc: Neal Cardwell Cc: Pavel Emelyanov Cc: Dave Jones Cc: Michael Kerrisk Signed-off-by: Andrey Vagin Andrey Vagin (2): tcp: make tcp_timestamp dependent on tcp_sock tcp: add ability to set a timestamp offset (v2) include/linux/tcp.h | 2 ++ include/net/tcp.h | 15 +++++++++----- include/uapi/linux/tcp.h | 1 + net/ipv4/syncookies.c | 4 ++-- net/ipv4/tcp.c | 9 +++++++- net/ipv4/tcp_bic.c | 10 ++++----- net/ipv4/tcp_cubic.c | 14 ++++++------- net/ipv4/tcp_htcp.c | 2 +- net/ipv4/tcp_input.c | 53 +++++++++++++++++++++++++----------------------- net/ipv4/tcp_ipv4.c | 19 +++++++++-------- net/ipv4/tcp_lp.c | 10 ++++----- net/ipv4/tcp_metrics.c | 2 +- net/ipv4/tcp_output.c | 35 +++++++++++++++++--------------- net/ipv4/tcp_timer.c | 9 ++++---- net/ipv4/tcp_westwood.c | 8 +++++--- net/ipv6/tcp_ipv6.c | 22 ++++++++++++-------- 16 files changed, 123 insertions(+), 92 deletions(-) -- 1.7.11.7