• Martin KaFai Lau's avatar
    tcp: Add RFC4898 tcpEStatsPerfDataSegsOut/In · a44d6eac
    Martin KaFai Lau authored
    Per RFC4898, they count segments sent/received
    containing a positive length data segment (that includes
    retransmission segments carrying data).  Unlike
    tcpi_segs_out/in, tcpi_data_segs_out/in excludes segments
    carrying no data (e.g. pure ack).
    
    The patch also updates the segs_in in tcp_fastopen_add_skb()
    so that segs_in >= data_segs_in property is kept.
    
    Together with retransmission data, tcpi_data_segs_out
    gives a better signal on the rxmit rate.
    
    v6: Rebase on the latest net-next
    
    v5: Eric pointed out that checking skb->len is still needed in
    tcp_fastopen_add_skb() because skb can carry a FIN without data.
    Hence, instead of open coding segs_in and data_segs_in, tcp_segs_in()
    helper is used.  Comment is added to the fastopen case to explain why
    segs_in has to be reset and tcp_segs_in() has to be called before
    __skb_pull().
    
    v4: Add comment to the changes in tcp_fastopen_add_skb()
    and also add remark on this case in the commit message.
    
    v3: Add const modifier to the skb parameter in tcp_segs_in()
    
    v2: Rework based on recent fix by Eric:
    commit a9d99ce2 ("tcp: fix tcpi_segs_in after connection establishment")
    Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
    Cc: Chris Rapier <rapier@psc.edu>
    Cc: Eric Dumazet <edumazet@google.com>
    Cc: Marcelo Ricardo Leitner <mleitner@redhat.com>
    Cc: Neal Cardwell <ncardwell@google.com>
    Cc: Yuchung Cheng <ycheng@google.com>
    Acked-by: default avatarEric Dumazet <edumazet@google.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    a44d6eac
tcp_ipv6.c 49.9 KB