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" <da...@davemloft.net> Cc: Alexey Kuznetsov <kuz...@ms2.inr.ac.ru> Cc: James Morris <jmor...@namei.org> Cc: Hideaki YOSHIFUJI <yoshf...@linux-ipv6.org> Cc: Patrick McHardy <ka...@trash.net> Cc: Eric Dumazet <eduma...@google.com> Cc: Yuchung Cheng <ych...@google.com> Cc: Neal Cardwell <ncardw...@google.com> Cc: Pavel Emelyanov <xe...@parallels.com> Cc: Dave Jones <da...@redhat.com> Cc: Michael Kerrisk <mtk.manpa...@gmail.com> Signed-off-by: Andrey Vagin <ava...@openvz.org> 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 majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
