From 5152fc7de3ae31b46692022ea63ce0501280f5b1 Mon Sep 17 00:00:00 2001 From: Damian Lukowski Date: Tue, 1 Sep 2009 10:24:00 +0000 Subject: [PATCH] RTO connection timeout: coding style fixes and comments This patch affects the retransmits_timed_out() function. Changes: 1) Variables have more meaningful names 2) retransmits_timed_out() has an introductionary comment. 3) Small coding style changes. Signed-off-by: Damian Lukowski Signed-off-by: David S. Miller --- include/net/tcp.h | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index e5319495f15e..df50bc40b5fd 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1252,22 +1252,27 @@ static inline struct sk_buff *tcp_write_queue_prev(struct sock *sk, struct sk_bu #define tcp_for_write_queue_from_safe(skb, tmp, sk) \ skb_queue_walk_from_safe(&(sk)->sk_write_queue, skb, tmp) +/* This function calculates a "timeout" which is equivalent to the timeout of a + * TCP connection after "boundary" unsucessful, exponentially backed-off + * retransmissions with an initial RTO of TCP_RTO_MIN. + */ static inline bool retransmits_timed_out(const struct sock *sk, unsigned int boundary) { - int limit, K; + unsigned int timeout, linear_backoff_thresh; + if (!inet_csk(sk)->icsk_retransmits) return false; - K = ilog2(TCP_RTO_MAX/TCP_RTO_MIN); + linear_backoff_thresh = ilog2(TCP_RTO_MAX/TCP_RTO_MIN); - if (boundary <= K) - limit = ((2 << boundary) - 1) * TCP_RTO_MIN; + if (boundary <= linear_backoff_thresh) + timeout = ((2 << boundary) - 1) * TCP_RTO_MIN; else - limit = ((2 << K) - 1) * TCP_RTO_MIN + - (boundary - K) * TCP_RTO_MAX; + timeout = ((2 << linear_backoff_thresh) - 1) * TCP_RTO_MIN + + (boundary - linear_backoff_thresh) * TCP_RTO_MAX; - return (tcp_time_stamp - tcp_sk(sk)->retrans_stamp) >= limit; + return (tcp_time_stamp - tcp_sk(sk)->retrans_stamp) >= timeout; } static inline struct sk_buff *tcp_send_head(struct sock *sk) -- 2.20.1