On Thu, Oct 8, 2015 at 11:16 AM, Eric Dumazet <eric.duma...@gmail.com> wrote:
> From: Eric Dumazet <eduma...@google.com>
>
> Before recent TCP listener patches, we were updating listener
> sk->sk_rxhash before the cloning of master socket.
>
> children sk_rxhash was therefore correct after the normal 3WHS.
>
> But with lockless listener, we no longer dirty/change listener sk_rxhash
> as it would be racy.
>
> We need to correctly update the child sk_rxhash, otherwise first data
> packet wont hit correct cpu if RFS is used.
>
> Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table")
> Signed-off-by: Eric Dumazet <eduma...@google.com>
> Reported-by: Willem de Bruijn <will...@google.com>
> Cc: Tom Herbert <t...@herbertland.com>
> ---
> net/ipv4/syncookies.c | 1 +
> net/ipv4/tcp_minisocks.c | 1 +
> 2 files changed, 2 insertions(+)
>
> diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
> index 8113c30ccf96..2dbb11331f6c 100644
> --- a/net/ipv4/syncookies.c
> +++ b/net/ipv4/syncookies.c
> @@ -225,6 +225,7 @@ struct sock *tcp_get_cookie_sock(struct sock *sk, struct
> sk_buff *skb,
> child = icsk->icsk_af_ops->syn_recv_sock(sk, skb, req, dst);
> if (child) {
> atomic_set(&req->rsk_refcnt, 1);
> + sock_rps_save_rxhash(child, skb);
> inet_csk_reqsk_queue_add(sk, req, child);
> } else {
> reqsk_free(req);
> diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
> index 9adf1e2c3170..1079e6ad77fe 100644
> --- a/net/ipv4/tcp_minisocks.c
> +++ b/net/ipv4/tcp_minisocks.c
> @@ -768,6 +768,7 @@ struct sock *tcp_check_req(struct sock *sk, struct
> sk_buff *skb,
> if (!child)
> goto listen_overflow;
>
> + sock_rps_save_rxhash(child, skb);
> tcp_synack_rtt_meas(child, req);
> inet_csk_reqsk_queue_drop(sk, req);
> inet_csk_reqsk_queue_add(sk, req, child);
>
>
Acked-by: Tom Herbert <t...@herbertland.com>
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
