tcp_write_xmit(sk, tp->nonagle))
tcp_write_xmit(sk, tcp_current_mss(sk, 1), tp->nonagle))
void __tcp_data_snd_check(struct sock *sk, struct sk_buff *skb){	struct tcp_sock *tp = tcp_sk(sk);	if (after(TCP_SKB_CB(skb)->end_seq, tp->snd_una + tp->snd_wnd) ||	    tcp_packets_in_flight(tp) >= tp->snd_cwnd ||	    tcp_write_xmit(sk, tp->nonagle))		tcp_check_probe_timer(sk, tp);}