Commit 756ee172 authored by Lawrence Brakmo's avatar Lawrence Brakmo Committed by David S. Miller

tcp: replace cnt & rtt with struct in pkts_acked()

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: default avatarLawrence Brakmo <brakmo@fb.com>
Acked-by: default avatarYuchung Cheng <ycheng@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent cf88585b
......@@ -854,6 +854,11 @@ 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;
......@@ -877,7 +882,7 @@ 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);
......
......@@ -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);
}
}
......
......@@ -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)
......
......@@ -437,21 +437,21 @@ 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;
......
......@@ -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 &&
......
......@@ -82,30 +82,31 @@ 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);
s32 rtt_us = sample->rtt_us;
ca->acked = pkts_acked;
ca->acked = sample->pkts_acked;
/* dup ack, no rtt sample */
if (rtt < 0)
if (rtt_us < 0)
return;
/* ignore bogus values, this prevents wraparound in alpha math */
if (rtt > RTT_MAX)
rtt = RTT_MAX;
if (rtt_us > RTT_MAX)
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 > rtt_us)
ca->base_rtt = rtt_us;
/* and max */
if (ca->max_rtt < rtt)
ca->max_rtt = rtt;
if (ca->max_rtt < rtt_us)
ca->max_rtt = rtt_us;
++ca->cnt_rtt;
ca->sum_rtt += rtt;
ca->sum_rtt += rtt_us;
}
/* Maximum queuing delay */
......
......@@ -3248,8 +3248,12 @@ 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 = pkts_acked,
.rtt_us = ca_rtt_us };
icsk->icsk_ca_ops->pkts_acked(sk, &sample);
}
#if FASTRETRANS_DEBUG > 0
WARN_ON((int)tp->sacked_out < 0);
......
......@@ -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)
......
......@@ -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)
......
......@@ -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);
......
......@@ -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)
......
......@@ -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);
}
/*
......
......@@ -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)
......
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