From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jon Maxwell Subject: [net-next, 3/3] tcp: convert icsk_user_timeout from jiffies to msecs Date: Fri, 13 Jul 2018 10:49:19 +1000 Message-ID: <20180713004919.18608-1-jmaxwell37@gmail.com> Cc: edumazet@google.com, ncardwell@google.com, David.Laight@aculab.com, kuznet@ms2.inr.ac.ru, yoshfuji@linux-ipv6.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, jmaxwell@redhat.com To: davem@davemloft.net Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org The final patch in this series. Create the tcp_clamp_rto_to_user_timeout() helper routine. To calculate the correct rto, so that the TCP_USER_TIMEOUT socket option is more accurate. Taking suggestions and feedback into account from Eric Dumazet, Neal Cardwell and David Laight. Due to the 1st commit we can avoid the msecs_to_jiffies() and jiffies_to_msecs() dance. Signed-off-by: Jon Maxwell --- net/ipv4/tcp_timer.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 8ab8c9645294..d4d4b30a6bec 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -36,6 +36,22 @@ u32 tcp_retransmit_stamp(const struct sock *sk) return start_ts; } +static u32 tcp_clamp_rto_to_user_timeout(const struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + u32 elapsed, start_ts; + + start_ts = tcp_retransmit_stamp(sk); + if (!icsk->icsk_user_timeout || !start_ts) + return icsk->icsk_rto; + elapsed = tcp_time_stamp(tcp_sk(sk)) - start_ts; + if (elapsed >= icsk->icsk_user_timeout) + return 1; /* user timeout has passed; fire ASAP */ + else + return min_t(u32, icsk->icsk_rto, msecs_to_jiffies(icsk->icsk_user_timeout - + elapsed)); +} + /** * tcp_write_err() - close socket and save error info * @sk: The socket the error has appeared on. @@ -544,7 +560,8 @@ void tcp_retransmit_timer(struct sock *sk) /* Use normal (exponential) backoff */ icsk->icsk_rto = min(icsk->icsk_rto << 1, TCP_RTO_MAX); } - inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, icsk->icsk_rto, TCP_RTO_MAX); + inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, + tcp_clamp_rto_to_user_timeout(sk), TCP_RTO_MAX); if (retransmits_timed_out(sk, net->ipv4.sysctl_tcp_retries1 + 1, 0)) __sk_dst_reset(sk); -- 2.13.6