tcp: fix tcp_rearm_rto() (b17b8a20) · Commits · 戴 / test

skbs in (re)transmit queue no longer have a copy of jiffies at the time of the transmit : skb->skb_mstamp is now in usec unit, with no correlation to tcp_jiffies32. We have to convert rto from jiffies to usec, compute a time difference in usec, then convert the delta to HZ units. Fixes: ("tcp: switch TCP TS option (RFC 7323) to 1ms clock") Signed-off-by:

Eric Dumazet <edumazet@google.com> Acked-by:

Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/ipv4/tcp_input.c

+6 −6

Original line number	Diff line number	Diff line
		@@ -3002,14 +3002,14 @@ void tcp_rearm_rto(struct sock *sk)
		if (icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT \|\|
		icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
		struct sk_buff *skb = tcp_write_queue_head(sk);
		const u32 rto_time_stamp =
		tcp_skb_timestamp(skb) + rto;
		s32 delta = (s32)(rto_time_stamp - tcp_jiffies32);
		/* delta may not be positive if the socket is locked
		u64 rto_time_stamp = skb->skb_mstamp +
		jiffies_to_usecs(rto);
		s64 delta_us = rto_time_stamp - tp->tcp_mstamp;
		/* delta_us may not be positive if the socket is locked
		* when the retrans timer fires and is rescheduled.
		*/
		if (delta > 0)
		rto = delta;
		if (delta_us > 0)
		rto = usecs_to_jiffies(delta_us);
		}
		inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, rto,
		TCP_RTO_MAX);

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