struct sk_buff *skb = sk->sk_send_head;  if (skb != NULL) __tcp_data_snd_check(sk, skb);
tcp_push_pending_frames(sk, tp);
static __inline__ void tcp_data_snd_check(struct sock *sk){	struct sk_buff *skb = sk->sk_send_head;	if (skb != NULL)		__tcp_data_snd_check(sk, skb);	tcp_check_space(sk);}