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" <[email protected]> Cc: Alexey Kuznetsov <[email protected]> Cc: James Morris <[email protected]> Cc: Hideaki YOSHIFUJI <[email protected]> Cc: Patrick McHardy <[email protected]> Cc: Eric Dumazet <[email protected]> Cc: Yuchung Cheng <[email protected]> Cc: Neal Cardwell <[email protected]> Cc: Pavel Emelyanov <[email protected]> Cc: Dave Jones <[email protected]> Cc: Michael Kerrisk <[email protected]> Signed-off-by: Andrey Vagin <[email protected]> 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
