From 205288c0ef4b4059c0ae8a2bb85b74a1c371d700 Mon Sep 17 00:00:00 2001 From: Neal Cardwell Date: Thu, 12 Oct 2017 23:44:27 -0400 Subject: [PATCH 04/19] net-tcp_bbr: v2: count packets lost over TCP rate sampling interval For understanding the relationship between inflight and packet loss signals, to try to find the highest inflight value that has acceptable levels of packet losses. Effort: net-tcp_bbr Origin-9xx-SHA1: 4527e26b2bd7756a88b5b9ef1ada3da33dd609ab Change-Id: I594c2500868d9c530770e7ddd68ffc87c57f4fd5 Signed-off-by: Alexandre Frade --- include/net/tcp.h | 5 ++++- net/ipv4/tcp_rate.c | 3 +++ 2 files changed, 7 insertions(+), 1 deletion(-) --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -985,6 +985,7 @@ struct tcp_skb_cb { #define TCPCB_IN_FLIGHT_MAX ((1U << TCPCB_IN_FLIGHT_BITS) - 1) u32 in_flight:20, /* packets in flight at transmit */ unused2:12; + u32 lost; /* packets lost so far upon tx of skb */ } tx; /* only used for outgoing skbs */ union { struct inet_skb_parm h4; @@ -1139,11 +1140,13 @@ struct ack_sample { */ struct rate_sample { u64 prior_mstamp; /* starting timestamp for interval */ + u32 prior_lost; /* tp->lost at "prior_mstamp" */ u32 prior_delivered; /* tp->delivered at "prior_mstamp" */ u32 prior_delivered_ce;/* tp->delivered_ce at "prior_mstamp" */ u32 tx_in_flight; /* packets in flight at starting timestamp */ + s32 lost; /* number of packets lost over interval */ s32 delivered; /* number of packets delivered over interval */ - s32 delivered_ce; /* number of packets delivered w/ CE marks*/ + s32 delivered_ce; /* packets delivered w/ CE mark over interval */ long interval_us; /* time for tp->delivered to incr "delivered" */ u32 snd_interval_us; /* snd interval for delivered packets */ u32 rcv_interval_us; /* rcv interval for delivered packets */ --- a/net/ipv4/tcp_rate.c +++ b/net/ipv4/tcp_rate.c @@ -84,6 +84,7 @@ void tcp_rate_skb_sent(struct sock *sk, TCP_SKB_CB(skb)->tx.delivered_mstamp = tp->delivered_mstamp; TCP_SKB_CB(skb)->tx.delivered = tp->delivered; TCP_SKB_CB(skb)->tx.delivered_ce = tp->delivered_ce; + TCP_SKB_CB(skb)->tx.lost = tp->lost; TCP_SKB_CB(skb)->tx.is_app_limited = tp->app_limited ? 1 : 0; tcp_set_tx_in_flight(sk, skb); } @@ -110,6 +111,7 @@ void tcp_rate_skb_delivered(struct sock if (!rs->prior_delivered || tcp_skb_sent_after(tx_tstamp, tp->first_tx_mstamp, scb->end_seq, rs->last_end_seq)) { + rs->prior_lost = scb->tx.lost; rs->prior_delivered_ce = scb->tx.delivered_ce; rs->prior_delivered = scb->tx.delivered; rs->prior_mstamp = scb->tx.delivered_mstamp; @@ -165,6 +167,7 @@ void tcp_rate_gen(struct sock *sk, u32 d return; } rs->delivered = tp->delivered - rs->prior_delivered; + rs->lost = tp->lost - rs->prior_lost; rs->delivered_ce = tp->delivered_ce - rs->prior_delivered_ce; /* delivered_ce occupies less than 32 bits in the skb control block */