On Wed, Mar 09, 2016 at 03:11:50PM -0800, Yuchung Cheng wrote: > On Wed, Mar 9, 2016 at 10:43 AM, Martin KaFai Lau <ka...@fb.com> wrote: > > diff --git a/include/net/tcp.h b/include/net/tcp.h > > index e90db85..24557a8 100644 > > --- a/include/net/tcp.h > > +++ b/include/net/tcp.h > > @@ -1816,4 +1816,14 @@ static inline void skb_set_tcp_pure_ack(struct > > sk_buff *skb) > > skb->truesize = 2; > > } > > > > +static inline void tcp_segs_in(struct tcp_sock *tp, const struct sk_buff > > *skb) > > +{ > > + u16 segs_in; > > + > > + segs_in = max_t(u16, 1, skb_shinfo(skb)->gso_segs); > > + tp->segs_in += segs_in; > > + if (skb->len > tcp_hdrlen(skb)) > > + tp->data_segs_in += segs_in; > > +} > > + > > #endif /* _TCP_H */ > > diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c > > index fdb286d..f583c85 100644 > > --- a/net/ipv4/tcp_fastopen.c > > +++ b/net/ipv4/tcp_fastopen.c > > @@ -131,6 +131,7 @@ static bool tcp_fastopen_cookie_gen(struct request_sock > > *req, > > void tcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb) > > { > > struct tcp_sock *tp = tcp_sk(sk); > > + u16 segs_in; > > > > if (TCP_SKB_CB(skb)->end_seq == tp->rcv_nxt) > > return; > > @@ -154,6 +155,9 @@ void tcp_fastopen_add_skb(struct sock *sk, struct > > sk_buff *skb) > > * as we certainly are not changing upper 32bit value (0) > > */ > > tp->bytes_received = skb->len; > > + segs_in = max_t(u16, 1, skb_shinfo(skb)->gso_segs); > > + tp->segs_in = segs_in; > > + tp->data_segs_in = segs_in; > why not use the new tcp_segs_in() helper? It is because segs_in has been set to 1 by tcp_create_openreq_child(), so calling tcp_segs_in() will have it double counted and tcphdr has been pulled from skb, so skb->len does not include tcp_hdrlen.
I will add some remark in this change.