From f19fd62dafaf1ed6cf615dba655b82fa9df59074 Mon Sep 17 00:00:00 2001 From: Neal Cardwell Date: Fri, 14 Jul 2017 17:49:22 -0400 Subject: [PATCH] tcp_bbr: introduce bbr_bw_to_pacing_rate() helper Introduce a helper to convert a BBR bandwidth and gain factor to a pacing rate in bytes per second. This is a pure refactor, but is needed for two following fixes. Fixes: 0f8782ea1497 ("tcp_bbr: add BBR congestion control") Signed-off-by: Neal Cardwell Signed-off-by: Yuchung Cheng Signed-off-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller --- net/ipv4/tcp_bbr.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/net/ipv4/tcp_bbr.c b/net/ipv4/tcp_bbr.c index 743e97511dc8..29e23b851b97 100644 --- a/net/ipv4/tcp_bbr.c +++ b/net/ipv4/tcp_bbr.c @@ -211,6 +211,16 @@ static u64 bbr_rate_bytes_per_sec(struct sock *sk, u64 rate, int gain) return rate >> BW_SCALE; } +/* Convert a BBR bw and gain factor to a pacing rate in bytes per second. */ +static u32 bbr_bw_to_pacing_rate(struct sock *sk, u32 bw, int gain) +{ + u64 rate = bw; + + rate = bbr_rate_bytes_per_sec(sk, rate, gain); + rate = min_t(u64, rate, sk->sk_max_pacing_rate); + return rate; +} + /* Pace using current bw estimate and a gain factor. In order to help drive the * network toward lower queues while maintaining high utilization and low * latency, the average pacing rate aims to be slightly (~1%) lower than the @@ -220,10 +230,8 @@ static u64 bbr_rate_bytes_per_sec(struct sock *sk, u64 rate, int gain) */ static void bbr_set_pacing_rate(struct sock *sk, u32 bw, int gain) { - u64 rate = bw; + u32 rate = bbr_bw_to_pacing_rate(sk, bw, gain); - rate = bbr_rate_bytes_per_sec(sk, rate, gain); - rate = min_t(u64, rate, sk->sk_max_pacing_rate); if (bbr_full_bw_reached(sk) || rate > sk->sk_pacing_rate) sk->sk_pacing_rate = rate; } -- 2.30.2