From 9bcc66e1983d10861deb6920fb0c151c5b01772a Mon Sep 17 00:00:00 2001 From: Jon Maxwell Date: Thu, 19 Jul 2018 11:14:42 +1000 Subject: tcp: convert icsk_user_timeout from jiffies to msecs This is a preparatory commit. Part of this series that improves the socket TCP_USER_TIMEOUT option accuracy. Implement Eric Dumazets idea to convert icsk->icsk_user_timeout from jiffies to msecs. To eliminate the msecs_to_jiffies() and jiffies_to_msecs() dance in future. Signed-off-by: Jon Maxwell Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 4 ++-- net/ipv4/tcp_timer.c | 8 ++++---- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index bce53b1728a6..514aaac1626f 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2989,7 +2989,7 @@ static int do_tcp_setsockopt(struct sock *sk, int level, if (val < 0) err = -EINVAL; else - icsk->icsk_user_timeout = msecs_to_jiffies(val); + icsk->icsk_user_timeout = val; break; case TCP_FASTOPEN: @@ -3445,7 +3445,7 @@ static int do_tcp_getsockopt(struct sock *sk, int level, break; case TCP_USER_TIMEOUT: - val = jiffies_to_msecs(icsk->icsk_user_timeout); + val = icsk->icsk_user_timeout; break; case TCP_FASTOPEN: diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 3b3611729928..fa34984d0b12 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -183,8 +183,9 @@ static bool retransmits_timed_out(struct sock *sk, else timeout = ((2 << linear_backoff_thresh) - 1) * rto_base + (boundary - linear_backoff_thresh) * TCP_RTO_MAX; + timeout = jiffies_to_msecs(timeout); } - return (tcp_time_stamp(tcp_sk(sk)) - start_ts) >= jiffies_to_msecs(timeout); + return (tcp_time_stamp(tcp_sk(sk)) - start_ts) >= timeout; } /* A write timeout has occurred. Process the after effects. */ @@ -337,8 +338,7 @@ static void tcp_probe_timer(struct sock *sk) if (!start_ts) skb->skb_mstamp = tp->tcp_mstamp; else if (icsk->icsk_user_timeout && - (s32)(tcp_time_stamp(tp) - start_ts) > - jiffies_to_msecs(icsk->icsk_user_timeout)) + (s32)(tcp_time_stamp(tp) - start_ts) > icsk->icsk_user_timeout) goto abort; max_probes = sock_net(sk)->ipv4.sysctl_tcp_retries2; @@ -672,7 +672,7 @@ static void tcp_keepalive_timer (struct timer_list *t) * to determine when to timeout instead. */ if ((icsk->icsk_user_timeout != 0 && - elapsed >= icsk->icsk_user_timeout && + elapsed >= msecs_to_jiffies(icsk->icsk_user_timeout) && icsk->icsk_probes_out > 0) || (icsk->icsk_user_timeout == 0 && icsk->icsk_probes_out >= keepalive_probes(tp))) { -- cgit From a7fa37703d495310819d0a6747e5b32362305374 Mon Sep 17 00:00:00 2001 From: Jon Maxwell Date: Thu, 19 Jul 2018 11:14:43 +1000 Subject: tcp: Add tcp_retransmit_stamp() helper routine Create a seperate helper routine as per Neal Cardwells suggestion. To be used by the final commit in this series and retransmits_timed_out(). Signed-off-by: Jon Maxwell Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp_timer.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index fa34984d0b12..d212f183dd2d 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -22,6 +22,20 @@ #include #include +u32 tcp_retransmit_stamp(const struct sock *sk) +{ + u32 start_ts = tcp_sk(sk)->retrans_stamp; + + if (unlikely(!start_ts)) { + struct sk_buff *head = tcp_rtx_queue_head(sk); + + if (!head) + return 0; + start_ts = tcp_skb_timestamp(head); + } + return start_ts; +} + /** * tcp_write_err() - close socket and save error info * @sk: The socket the error has appeared on. @@ -166,14 +180,9 @@ static bool retransmits_timed_out(struct sock *sk, if (!inet_csk(sk)->icsk_retransmits) return false; - start_ts = tcp_sk(sk)->retrans_stamp; - if (unlikely(!start_ts)) { - struct sk_buff *head = tcp_rtx_queue_head(sk); - - if (!head) - return false; - start_ts = tcp_skb_timestamp(head); - } + start_ts = tcp_retransmit_stamp(sk); + if (!start_ts) + return false; if (likely(timeout == 0)) { linear_backoff_thresh = ilog2(TCP_RTO_MAX/rto_base); -- cgit From b701a99e431db784714c32fc6b68123045714679 Mon Sep 17 00:00:00 2001 From: Jon Maxwell Date: Thu, 19 Jul 2018 11:14:44 +1000 Subject: tcp: Add tcp_clamp_rto_to_user_timeout() helper to improve accuracy 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 Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp_timer.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index d212f183dd2d..a242f8874629 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -36,6 +36,21 @@ 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 +559,8 @@ out_reset_timer: /* 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); -- cgit