taglinefilesource code
when48include/linux/skbuff.hvolatile unsigned long  when;      /* used to compute rtt's      */
when613net/core/skbuff.cn->when=skb->when;
when1761net/ipv4/ip.cskb->when = jiffies;
when2465net/ipv4/ip.cskb->when=jiffies;
when2593net/ipv4/ip.cskb->when = jiffies;
when460net/ipv4/tcp.cskb->when = jiffies;
when590net/ipv4/tcp.cstatic void reset_xmit_timer(struct sock *sk, int why, unsigned long when)
when594net/ipv4/tcp.cif((int)when < 0)
when596net/ipv4/tcp.cwhen=3;
when599net/ipv4/tcp.csk->retransmit_timer.expires=when;
when801net/ipv4/tcp.cif (jiffies < skb->when + sk->rto) 
when803net/ipv4/tcp.creset_xmit_timer (sk, TIME_WRITE, skb->when + sk->rto - jiffies);
when3433net/ipv4/tcp.cm = jiffies - oskb->when;  /* RTT */
when3688net/ipv4/tcp.c(sk->send_head->when + sk->rto < jiffies))) 
when3690net/ipv4/tcp.cif(sk->send_head->when + sk->rto < jiffies)