On Tue, Aug 25, 2015 at 4:33 PM, Lawrence Brakmo <bra...@fb.com> wrote:
> Replace 2 arguments (cnt and rtt) in the congestion control modules'
> pkts_acked() function with a struct. This will allow adding more
> information without having to modify existing congestion control
> modules (tcp_nv in particular needs bytes in flight when packet
> was sent).
>
> As proposed by Neal Cardwell in his comments to the tcp_nv patch.
>
> Signed-off-by: Lawrence Brakmo <bra...@fb.com>
Acked-by: Yuchung Cheng <ych...@google.com>
> ---
> include/net/tcp.h | 7 ++++++-
> net/ipv4/tcp_bic.c | 6 +++---
> net/ipv4/tcp_cdg.c | 14 +++++++-------
> net/ipv4/tcp_cubic.c | 6 +++---
> net/ipv4/tcp_htcp.c | 10 +++++-----
> net/ipv4/tcp_illinois.c | 20 ++++++++++----------
> net/ipv4/tcp_input.c | 7 +++++--
> net/ipv4/tcp_lp.c | 6 +++---
> net/ipv4/tcp_vegas.c | 6 +++---
> net/ipv4/tcp_vegas.h | 2 +-
> net/ipv4/tcp_veno.c | 7 ++++---
> net/ipv4/tcp_westwood.c | 7 ++++---
> net/ipv4/tcp_yeah.c | 7 ++++---
> 13 files changed, 58 insertions(+), 47 deletions(-)
>
> diff --git a/include/net/tcp.h b/include/net/tcp.h
> index 364426a..0121529 100644
> --- a/include/net/tcp.h
> +++ b/include/net/tcp.h
> @@ -834,6 +834,11 @@ enum tcp_ca_ack_event_flags {
>
> union tcp_cc_info;
>
> +struct ack_sample {
> + u32 pkts_acked;
> + s32 rtt_us;
> +};
> +
> struct tcp_congestion_ops {
> struct list_head list;
> u32 key;
> @@ -857,7 +862,7 @@ struct tcp_congestion_ops {
> /* new value of cwnd after loss (optional) */
> u32 (*undo_cwnd)(struct sock *sk);
> /* hook for packet ack accounting (optional) */
> - void (*pkts_acked)(struct sock *sk, u32 num_acked, s32 rtt_us);
> + void (*pkts_acked)(struct sock *sk, const struct ack_sample *sample);
> /* get info for inet_diag (optional) */
> size_t (*get_info)(struct sock *sk, u32 ext, int *attr,
> union tcp_cc_info *info);
> diff --git a/net/ipv4/tcp_bic.c b/net/ipv4/tcp_bic.c
> index fd1405d..f469f1b 100644
> --- a/net/ipv4/tcp_bic.c
> +++ b/net/ipv4/tcp_bic.c
> @@ -197,15 +197,15 @@ static void bictcp_state(struct sock *sk, u8 new_state)
> /* Track delayed acknowledgment ratio using sliding window
> * ratio = (15*ratio + sample) / 16
> */
> -static void bictcp_acked(struct sock *sk, u32 cnt, s32 rtt)
> +static void bictcp_acked(struct sock *sk, const struct ack_sample *sample)
> {
> const struct inet_connection_sock *icsk = inet_csk(sk);
>
> if (icsk->icsk_ca_state == TCP_CA_Open) {
> struct bictcp *ca = inet_csk_ca(sk);
>
> - cnt -= ca->delayed_ack >> ACK_RATIO_SHIFT;
> - ca->delayed_ack += cnt;
> + ca->delayed_ack += sample->pkts_acked -
> + (ca->delayed_ack >> ACK_RATIO_SHIFT);
> }
> }
>
> diff --git a/net/ipv4/tcp_cdg.c b/net/ipv4/tcp_cdg.c
> index 167b6a3..b4e5af7 100644
> --- a/net/ipv4/tcp_cdg.c
> +++ b/net/ipv4/tcp_cdg.c
> @@ -294,12 +294,12 @@ static void tcp_cdg_cong_avoid(struct sock *sk, u32
> ack, u32 acked)
> ca->shadow_wnd = max(ca->shadow_wnd, ca->shadow_wnd + incr);
> }
>
> -static void tcp_cdg_acked(struct sock *sk, u32 num_acked, s32 rtt_us)
> +static void tcp_cdg_acked(struct sock *sk, const struct ack_sample *sample)
> {
> struct cdg *ca = inet_csk_ca(sk);
> struct tcp_sock *tp = tcp_sk(sk);
>
> - if (rtt_us <= 0)
> + if (sample->rtt_us <= 0)
> return;
>
> /* A heuristic for filtering delayed ACKs, adapted from:
> @@ -307,20 +307,20 @@ static void tcp_cdg_acked(struct sock *sk, u32
> num_acked, s32 rtt_us)
> * delay and rate based TCP mechanisms." TR 100219A. CAIA, 2010.
> */
> if (tp->sacked_out == 0) {
> - if (num_acked == 1 && ca->delack) {
> + if (sample->pkts_acked == 1 && ca->delack) {
> /* A delayed ACK is only used for the minimum if it is
> * provenly lower than an existing non-zero minimum.
> */
> - ca->rtt.min = min(ca->rtt.min, rtt_us);
> + ca->rtt.min = min(ca->rtt.min, sample->rtt_us);
> ca->delack--;
> return;
> - } else if (num_acked > 1 && ca->delack < 5) {
> + } else if (sample->pkts_acked > 1 && ca->delack < 5) {
> ca->delack++;
> }
> }
>
> - ca->rtt.min = min_not_zero(ca->rtt.min, rtt_us);
> - ca->rtt.max = max(ca->rtt.max, rtt_us);
> + ca->rtt.min = min_not_zero(ca->rtt.min, sample->rtt_us);
> + ca->rtt.max = max(ca->rtt.max, sample->rtt_us);
> }
>
> static u32 tcp_cdg_ssthresh(struct sock *sk)
> diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c
> index 28011fb..c5d0ba5 100644
> --- a/net/ipv4/tcp_cubic.c
> +++ b/net/ipv4/tcp_cubic.c
> @@ -416,21 +416,21 @@ static void hystart_update(struct sock *sk, u32 delay)
> /* Track delayed acknowledgment ratio using sliding window
> * ratio = (15*ratio + sample) / 16
> */
> -static void bictcp_acked(struct sock *sk, u32 cnt, s32 rtt_us)
> +static void bictcp_acked(struct sock *sk, const struct ack_sample *sample)
> {
> const struct tcp_sock *tp = tcp_sk(sk);
> struct bictcp *ca = inet_csk_ca(sk);
> u32 delay;
>
> /* Some calls are for duplicates without timetamps */
> - if (rtt_us < 0)
> + if (sample->rtt_us < 0)
> return;
>
> /* Discard delay samples right after fast recovery */
> if (ca->epoch_start && (s32)(tcp_time_stamp - ca->epoch_start) < HZ)
> return;
>
> - delay = (rtt_us << 3) / USEC_PER_MSEC;
> + delay = (sample->rtt_us << 3) / USEC_PER_MSEC;
> if (delay == 0)
> delay = 1;
>
> diff --git a/net/ipv4/tcp_htcp.c b/net/ipv4/tcp_htcp.c
> index 82f0d9e..4a4d8e7 100644
> --- a/net/ipv4/tcp_htcp.c
> +++ b/net/ipv4/tcp_htcp.c
> @@ -99,7 +99,7 @@ static inline void measure_rtt(struct sock *sk, u32 srtt)
> }
>
> static void measure_achieved_throughput(struct sock *sk,
> - u32 pkts_acked, s32 rtt)
> + const struct ack_sample *sample)
> {
> const struct inet_connection_sock *icsk = inet_csk(sk);
> const struct tcp_sock *tp = tcp_sk(sk);
> @@ -107,10 +107,10 @@ static void measure_achieved_throughput(struct sock *sk,
> u32 now = tcp_time_stamp;
>
> if (icsk->icsk_ca_state == TCP_CA_Open)
> - ca->pkts_acked = pkts_acked;
> + ca->pkts_acked = sample->pkts_acked;
>
> - if (rtt > 0)
> - measure_rtt(sk, usecs_to_jiffies(rtt));
> + if (sample->rtt_us > 0)
> + measure_rtt(sk, usecs_to_jiffies(sample->rtt_us));
>
> if (!use_bandwidth_switch)
> return;
> @@ -122,7 +122,7 @@ static void measure_achieved_throughput(struct sock *sk,
> return;
> }
>
> - ca->packetcount += pkts_acked;
> + ca->packetcount += sample->pkts_acked;
>
> if (ca->packetcount >= tp->snd_cwnd - (ca->alpha >> 7 ? : 1) &&
> now - ca->lasttime >= ca->minRTT &&
> diff --git a/net/ipv4/tcp_illinois.c b/net/ipv4/tcp_illinois.c
> index 2ab9bbb..77ad119 100644
> --- a/net/ipv4/tcp_illinois.c
> +++ b/net/ipv4/tcp_illinois.c
> @@ -82,30 +82,30 @@ static void tcp_illinois_init(struct sock *sk)
> }
>
> /* Measure RTT for each ack. */
> -static void tcp_illinois_acked(struct sock *sk, u32 pkts_acked, s32 rtt)
> +static void tcp_illinois_acked(struct sock *sk, const struct ack_sample
> *sample)
> {
> struct illinois *ca = inet_csk_ca(sk);
>
> - ca->acked = pkts_acked;
> + ca->acked = sample->pkts_acked;
>
> /* dup ack, no rtt sample */
> - if (rtt < 0)
> + if (sample->rtt_us < 0)
> return;
>
> /* ignore bogus values, this prevents wraparound in alpha math */
> - if (rtt > RTT_MAX)
> - rtt = RTT_MAX;
> + if (sample->rtt_us > RTT_MAX)
> + sample->rtt_us = RTT_MAX;
>
> /* keep track of minimum RTT seen so far */
> - if (ca->base_rtt > rtt)
> - ca->base_rtt = rtt;
> + if (ca->base_rtt > sample->rtt_us)
> + ca->base_rtt = sample->rtt_us;
>
> /* and max */
> - if (ca->max_rtt < rtt)
> - ca->max_rtt = rtt;
> + if (ca->max_rtt < sample->rtt_us)
> + ca->max_rtt = sample->rtt_us;
>
> ++ca->cnt_rtt;
> - ca->sum_rtt += rtt;
> + ca->sum_rtt += sample->rtt_us;
> }
>
> /* Maximum queuing delay */
> diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
> index 4e4d6bc..f506a0a 100644
> --- a/net/ipv4/tcp_input.c
> +++ b/net/ipv4/tcp_input.c
> @@ -3196,8 +3196,11 @@ static int tcp_clean_rtx_queue(struct sock *sk, int
> prior_fackets,
> tcp_rearm_rto(sk);
> }
>
> - if (icsk->icsk_ca_ops->pkts_acked)
> - icsk->icsk_ca_ops->pkts_acked(sk, pkts_acked, ca_rtt_us);
> + if (icsk->icsk_ca_ops->pkts_acked) {
> + struct ack_sample sample = {pkts_acked, ca_rtt_us};
> +
> + icsk->icsk_ca_ops->pkts_acked(sk, &sample);
> + }
>
> #if FASTRETRANS_DEBUG > 0
> WARN_ON((int)tp->sacked_out < 0);
> diff --git a/net/ipv4/tcp_lp.c b/net/ipv4/tcp_lp.c
> index 1e70fa8..c67ece1 100644
> --- a/net/ipv4/tcp_lp.c
> +++ b/net/ipv4/tcp_lp.c
> @@ -260,13 +260,13 @@ static void tcp_lp_rtt_sample(struct sock *sk, u32 rtt)
> * newReno in increase case.
> * We work it out by following the idea from TCP-LP's paper directly
> */
> -static void tcp_lp_pkts_acked(struct sock *sk, u32 num_acked, s32 rtt_us)
> +static void tcp_lp_pkts_acked(struct sock *sk, const struct ack_sample
> *sample)
> {
> struct tcp_sock *tp = tcp_sk(sk);
> struct lp *lp = inet_csk_ca(sk);
>
> - if (rtt_us > 0)
> - tcp_lp_rtt_sample(sk, rtt_us);
> + if (sample->rtt_us > 0)
> + tcp_lp_rtt_sample(sk, sample->rtt_us);
>
> /* calc inference */
> if (tcp_time_stamp > tp->rx_opt.rcv_tsecr)
> diff --git a/net/ipv4/tcp_vegas.c b/net/ipv4/tcp_vegas.c
> index 13951c4..4c4bac1 100644
> --- a/net/ipv4/tcp_vegas.c
> +++ b/net/ipv4/tcp_vegas.c
> @@ -107,16 +107,16 @@ EXPORT_SYMBOL_GPL(tcp_vegas_init);
> * o min-filter RTT samples from a much longer window (forever for now)
> * to find the propagation delay (baseRTT)
> */
> -void tcp_vegas_pkts_acked(struct sock *sk, u32 cnt, s32 rtt_us)
> +void tcp_vegas_pkts_acked(struct sock *sk, const struct ack_sample *sample)
> {
> struct vegas *vegas = inet_csk_ca(sk);
> u32 vrtt;
>
> - if (rtt_us < 0)
> + if (sample->rtt_us < 0)
> return;
>
> /* Never allow zero rtt or baseRTT */
> - vrtt = rtt_us + 1;
> + vrtt = sample->rtt_us + 1;
>
> /* Filter to find propagation delay: */
> if (vrtt < vegas->baseRTT)
> diff --git a/net/ipv4/tcp_vegas.h b/net/ipv4/tcp_vegas.h
> index ef9da53..248cfc0 100644
> --- a/net/ipv4/tcp_vegas.h
> +++ b/net/ipv4/tcp_vegas.h
> @@ -17,7 +17,7 @@ struct vegas {
>
> void tcp_vegas_init(struct sock *sk);
> void tcp_vegas_state(struct sock *sk, u8 ca_state);
> -void tcp_vegas_pkts_acked(struct sock *sk, u32 cnt, s32 rtt_us);
> +void tcp_vegas_pkts_acked(struct sock *sk, const struct ack_sample *sample);
> void tcp_vegas_cwnd_event(struct sock *sk, enum tcp_ca_event event);
> size_t tcp_vegas_get_info(struct sock *sk, u32 ext, int *attr,
> union tcp_cc_info *info);
> diff --git a/net/ipv4/tcp_veno.c b/net/ipv4/tcp_veno.c
> index 0d094b9..40171e1 100644
> --- a/net/ipv4/tcp_veno.c
> +++ b/net/ipv4/tcp_veno.c
> @@ -69,16 +69,17 @@ static void tcp_veno_init(struct sock *sk)
> }
>
> /* Do rtt sampling needed for Veno. */
> -static void tcp_veno_pkts_acked(struct sock *sk, u32 cnt, s32 rtt_us)
> +static void tcp_veno_pkts_acked(struct sock *sk,
> + const struct ack_sample *sample)
> {
> struct veno *veno = inet_csk_ca(sk);
> u32 vrtt;
>
> - if (rtt_us < 0)
> + if (sample->rtt_us < 0)
> return;
>
> /* Never allow zero rtt or baseRTT */
> - vrtt = rtt_us + 1;
> + vrtt = sample->rtt_us + 1;
>
> /* Filter to find propagation delay: */
> if (vrtt < veno->basertt)
> diff --git a/net/ipv4/tcp_westwood.c b/net/ipv4/tcp_westwood.c
> index c10732e..4b03a2e 100644
> --- a/net/ipv4/tcp_westwood.c
> +++ b/net/ipv4/tcp_westwood.c
> @@ -99,12 +99,13 @@ static void westwood_filter(struct westwood *w, u32 delta)
> * Called after processing group of packets.
> * but all westwood needs is the last sample of srtt.
> */
> -static void tcp_westwood_pkts_acked(struct sock *sk, u32 cnt, s32 rtt)
> +static void tcp_westwood_pkts_acked(struct sock *sk,
> + const struct ack_sample *sample)
> {
> struct westwood *w = inet_csk_ca(sk);
>
> - if (rtt > 0)
> - w->rtt = usecs_to_jiffies(rtt);
> + if (sample->rtt_us > 0)
> + w->rtt = usecs_to_jiffies(sample->rtt_us);
> }
>
> /*
> diff --git a/net/ipv4/tcp_yeah.c b/net/ipv4/tcp_yeah.c
> index 17d3566..1b9d013 100644
> --- a/net/ipv4/tcp_yeah.c
> +++ b/net/ipv4/tcp_yeah.c
> @@ -56,15 +56,16 @@ static void tcp_yeah_init(struct sock *sk)
> tp->snd_cwnd_clamp = min_t(u32, tp->snd_cwnd_clamp, 0xffffffff/128);
> }
>
> -static void tcp_yeah_pkts_acked(struct sock *sk, u32 pkts_acked, s32 rtt_us)
> +static void tcp_yeah_pkts_acked(struct sock *sk,
> + const struct ack_sample *sample)
> {
> const struct inet_connection_sock *icsk = inet_csk(sk);
> struct yeah *yeah = inet_csk_ca(sk);
>
> if (icsk->icsk_ca_state == TCP_CA_Open)
> - yeah->pkts_acked = pkts_acked;
> + yeah->pkts_acked = sample->pkts_acked;
>
> - tcp_vegas_pkts_acked(sk, pkts_acked, rtt_us);
> + tcp_vegas_pkts_acked(sk, sample);
> }
>
> static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, u32 acked)
> --
> 1.8.1
>
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