taglinefilesource code
when56include/linux/skbuff.hunsigned long  when;      /* used to compute rtt's      */
when705net/core/skbuff.cn->when=skb->when;
when355net/ipv4/ip_output.cskb->when = jiffies;
when658net/ipv4/ip_output.cskb->when=jiffies;
when824net/ipv4/ip_output.cskb->when = jiffies;
when708net/ipv4/tcp.cskb->when = jiffies;
when868net/ipv4/tcp.cstatic void reset_xmit_timer(struct sock *sk, int why, unsigned long when)
when872net/ipv4/tcp.cif((long)when < 0)
when874net/ipv4/tcp.cwhen=3;
when877net/ipv4/tcp.csk->retransmit_timer.expires=jiffies+when;
when1088net/ipv4/tcp.cif (jiffies < skb->when + sk->rto) 
when1092net/ipv4/tcp.creset_xmit_timer (sk, TIME_WRITE, skb->when + sk->rto - jiffies);
when3808net/ipv4/tcp.cm = jiffies - oskb->when;  /* RTT */
when4064net/ipv4/tcp.c(sk->send_head->when + sk->rto < jiffies))) 
when4066net/ipv4/tcp.cif(sk->send_head->when + sk->rto < jiffies)