From ec3a63655f8ed63a7d1d706f50151e132abc0561 Mon Sep 17 00:00:00 2001 From: Florin Coras Date: Thu, 6 Jan 2022 17:47:14 -0800 Subject: tcp: optimize newreno cong ack handler Type: improvement Signed-off-by: Florin Coras Change-Id: I196ee5f4630cec637245493f370b5f83a939fe44 --- src/vnet/tcp/tcp_newreno.c | 39 ++++++++++++++++++++------------------- 1 file changed, 20 insertions(+), 19 deletions(-) diff --git a/src/vnet/tcp/tcp_newreno.c b/src/vnet/tcp/tcp_newreno.c index 39035bac00c..8c7e77fc974 100644 --- a/src/vnet/tcp/tcp_newreno.c +++ b/src/vnet/tcp/tcp_newreno.c @@ -62,30 +62,31 @@ void newreno_rcv_cong_ack (tcp_connection_t * tc, tcp_cc_ack_t ack_type, tcp_rate_sample_t * rs) { + /* With sacks prr controls the data in flight post congestion */ + if (PREDICT_TRUE (tcp_opts_sack_permitted (tc))) + return; + if (ack_type == TCP_CC_DUPACK) { - if (!tcp_opts_sack_permitted (tc)) - tc->cwnd += tc->snd_mss; + tc->cwnd += tc->snd_mss; } else if (ack_type == TCP_CC_PARTIALACK) { - /* RFC 6582 Sec. 3.2 */ - if (!tcp_opts_sack_permitted (&tc->rcv_opts)) - { - /* Deflate the congestion window by the amount of new data - * acknowledged by the Cumulative Acknowledgment field. - * If the partial ACK acknowledges at least one SMSS of new data, - * then add back SMSS bytes to the congestion window. This - * artificially inflates the congestion window in order to reflect - * the additional segment that has left the network. This "partial - * window deflation" attempts to ensure that, when fast recovery - * eventually ends, approximately ssthresh amount of data will be - * outstanding in the network.*/ - tc->cwnd = (tc->cwnd > tc->bytes_acked + tc->snd_mss) ? - tc->cwnd - tc->bytes_acked : tc->snd_mss; - if (tc->bytes_acked > tc->snd_mss) - tc->cwnd += tc->snd_mss; - } + /* RFC 6582 Sec. 3.2 + * Deflate the congestion window by the amount of new data + * acknowledged by the Cumulative Acknowledgment field. + * If the partial ACK acknowledges at least one SMSS of new data, + * then add back SMSS bytes to the congestion window. This + * artificially inflates the congestion window in order to reflect + * the additional segment that has left the network. This "partial + * window deflation" attempts to ensure that, when fast recovery + * eventually ends, approximately ssthresh amount of data will be + * outstanding in the network. */ + tc->cwnd = (tc->cwnd > tc->bytes_acked + tc->snd_mss) ? + tc->cwnd - tc->bytes_acked : + tc->snd_mss; + if (tc->bytes_acked > tc->snd_mss) + tc->cwnd += tc->snd_mss; } } -- cgit 1.2.3-korg