commit d62f9c9d0058ba3bfa8fe226c697abb05a477c5a Author: Mike Perry <mikeperry-git@torproject.org> Date: Fri Jan 21 23:20:52 2022 +0000 Only apply more frequent cwnd updates after slow start. --- src/core/or/congestion_control_st.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/src/core/or/congestion_control_st.h b/src/core/or/congestion_control_st.h index 0d6bf0b662..ea80868350 100644 --- a/src/core/or/congestion_control_st.h +++ b/src/core/or/congestion_control_st.h @@ -206,7 +206,8 @@ struct congestion_control_t { * * Congestion control literature recommends only one update of cwnd per * cwnd worth of acks. However, we can also tune this to be more frequent - * by increasing the 'cc_cwnd_inc_rate' consensus parameter. + * by increasing the 'cc_cwnd_inc_rate' consensus parameter. This tuning + * only applies after slow start. * * If this returns 0 due to high cwnd_inc_rate, the calling code will * update every sendme ack. @@ -215,8 +216,13 @@ static inline uint64_t CWND_UPDATE_RATE(const struct congestion_control_t *cc) { /* We add cwnd_inc_rate*sendme_inc/2 to round to nearest integer number * of acks */ - return ((cc->cwnd + cc->cwnd_inc_rate*cc->sendme_inc/2) + + if (cc->in_slow_start) { + return ((cc->cwnd + cc->sendme_inc/2)/cc->sendme_inc); + } else { + return ((cc->cwnd + cc->cwnd_inc_rate*cc->sendme_inc/2) / (cc->cwnd_inc_rate*cc->sendme_inc)); + } } /**