Re: [PATCH 1/2] tcp: make tcp_timestamp dependent on tcp_sock

Eric Dumazet
2013-01-23T16:27:03Z

On Wed, 2013-01-23 at 19:01 +0400, Andrey Vagin wrote:
> This will be used for setting timestamp offset.
>
> This patch converts the macros tcp_timestamp to a function with one
> argument "struct tcp_sock *tp" and nothing else.
>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
> Cc: James Morris <jmorris@namei.org>
> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
> Cc: Patrick McHardy <kaber@trash.net>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: Yuchung Cheng <ycheng@google.com>
> Cc: Neal Cardwell <ncardwell@google.com>
> Cc: Pavel Emelyanov <xemul@parallels.com>
> Cc: Dave Jones <davej@redhat.com>
> Cc: Michael Kerrisk <mtk.manpages@gmail.com>
> Signed-off-by: Andrey Vagin <avagin@openvz.org>
> ---
> include/net/tcp.h | 15 +++++++++-----
> net/ipv4/syncookies.c | 4 ++--
> net/ipv4/tcp.c | 2 +-
> 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 | 8 ++++----
> 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 +++++++++++---------
> 14 files changed, 112 insertions(+), 91 deletions(-)
>
> diff --git a/include/net/tcp.h b/include/net/tcp.h
> index aed42c7..3e242ba 100644
> --- a/include/net/tcp.h
> +++ b/include/net/tcp.h
> @@ -503,7 +503,7 @@ static inline __u32 cookie_v4_init_sequence(struct sock *sk,
> }
> #endif
>
> -extern __u32 cookie_init_timestamp(struct request_sock *req);
> +extern __u32 cookie_init_timestamp(struct tcp_sock *tp, struct request_sock *req);
> extern bool cookie_check_timestamp(struct tcp_options_received *opt, bool *);
>
> /* From net/ipv6/syncookies.c */
> @@ -675,7 +675,10 @@ void tcp_send_window_probe(struct sock *sk);
> * to use only the low 32-bits of jiffies and hide the ugly
> * casts with the following macro.
> */
> -#define tcp_time_stamp ((__u32)(jiffies))
> +static inline u32 tcp_time_stamp(const struct tcp_sock *tp)
> +{
> + return (__u32)jiffies;
> +}
>
> #define tcp_flag_byte(th) (((u_int8_t *)th)[13])
>
> @@ -1142,9 +1145,11 @@ static inline void tcp_openreq_init(struct request_sock *req,
> static inline void tcp_synack_rtt_meas(struct sock *sk,
> struct request_sock *req)
> {
> + const struct tcp_sock *tp = tcp_sk(sk);
> +
> if (tcp_rsk(req)->snt_synack)
> tcp_valid_rtt_meas(sk,
> - tcp_time_stamp - tcp_rsk(req)->snt_synack);
> + tcp_time_stamp(tp) - tcp_rsk(req)->snt_synack);
> }
>

This first chunk looks not needed.

Can SYN_RECV sockets be live-migrated ? Probably not.

Quite frankly I am sure there is an issue for timewait (not real
sockets).

Have you really tested this patch, or is it an RFC ?