From 164891aadf1721fca4dce473bb0e0998181537c6 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Mon, 23 Apr 2007 22:26:16 -0700 Subject: [PATCH] [TCP]: Congestion control API update. Do some simple changes to make congestion control API faster/cleaner. * use ktime_t rather than timeval * merge rtt sampling into existing ack callback this means one indirect call versus two per ack. * use flags bits to store options/settings Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- include/linux/skbuff.h | 5 +++++ include/net/tcp.h | 9 +++++---- net/ipv4/tcp_bic.c | 2 +- net/ipv4/tcp_cong.c | 14 +++++++------- net/ipv4/tcp_cubic.c | 2 +- net/ipv4/tcp_htcp.c | 2 +- net/ipv4/tcp_illinois.c | 16 +++++++--------- net/ipv4/tcp_input.c | 25 ++++++++----------------- net/ipv4/tcp_lp.c | 8 +++++--- net/ipv4/tcp_output.c | 2 +- net/ipv4/tcp_vegas.c | 10 +++++++--- net/ipv4/tcp_veno.c | 10 +++++++--- net/ipv4/tcp_westwood.c | 2 +- net/ipv4/tcp_yeah.c | 6 ++++-- net/ipv4/tcp_yeah.h | 7 +++++-- 15 files changed, 65 insertions(+), 55 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 50f6f6a094c..2694cb3ca76 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1569,6 +1569,11 @@ static inline void __net_timestamp(struct sk_buff *skb) skb->tstamp = ktime_get_real(); } +static inline ktime_t net_timedelta(ktime_t t) +{ + return ktime_sub(ktime_get_real(), t); +} + extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len); extern __sum16 __skb_checksum_complete(struct sk_buff *skb); diff --git a/include/net/tcp.h b/include/net/tcp.h index 43910fe3c44..a385797f160 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -629,9 +629,12 @@ enum tcp_ca_event { #define TCP_CA_MAX 128 #define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX) +#define TCP_CONG_NON_RESTRICTED 0x1 +#define TCP_CONG_RTT_STAMP 0x2 + struct tcp_congestion_ops { struct list_head list; - int non_restricted; + unsigned long flags; /* initialize private data (optional) */ void (*init)(struct sock *sk); @@ -645,8 +648,6 @@ struct tcp_congestion_ops { /* do new cwnd calculation (required) */ void (*cong_avoid)(struct sock *sk, u32 ack, u32 rtt, u32 in_flight, int good_ack); - /* round trip time sample per acked packet (optional) */ - void (*rtt_sample)(struct sock *sk, u32 usrtt); /* call before changing ca_state (optional) */ void (*set_state)(struct sock *sk, u8 new_state); /* call when cwnd event occurs (optional) */ @@ -654,7 +655,7 @@ 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); + void (*pkts_acked)(struct sock *sk, u32 num_acked, ktime_t last); /* get info for inet_diag (optional) */ void (*get_info)(struct sock *sk, u32 ext, struct sk_buff *skb); diff --git a/net/ipv4/tcp_bic.c b/net/ipv4/tcp_bic.c index 5730333cd0a..281c9f91325 100644 --- a/net/ipv4/tcp_bic.c +++ b/net/ipv4/tcp_bic.c @@ -206,7 +206,7 @@ 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) +static void bictcp_acked(struct sock *sk, u32 cnt, ktime_t last) { const struct inet_connection_sock *icsk = inet_csk(sk); diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c index ccd88407e0c..86b26539e54 100644 --- a/net/ipv4/tcp_cong.c +++ b/net/ipv4/tcp_cong.c @@ -126,7 +126,7 @@ int tcp_set_default_congestion_control(const char *name) #endif if (ca) { - ca->non_restricted = 1; /* default is always allowed */ + ca->flags |= TCP_CONG_NON_RESTRICTED; /* default is always allowed */ list_move(&ca->list, &tcp_cong_list); ret = 0; } @@ -181,7 +181,7 @@ void tcp_get_allowed_congestion_control(char *buf, size_t maxlen) *buf = '\0'; rcu_read_lock(); list_for_each_entry_rcu(ca, &tcp_cong_list, list) { - if (!ca->non_restricted) + if (!(ca->flags & TCP_CONG_NON_RESTRICTED)) continue; offs += snprintf(buf + offs, maxlen - offs, "%s%s", @@ -212,16 +212,16 @@ int tcp_set_allowed_congestion_control(char *val) } } - /* pass 2 clear */ + /* pass 2 clear old values */ list_for_each_entry_rcu(ca, &tcp_cong_list, list) - ca->non_restricted = 0; + ca->flags &= ~TCP_CONG_NON_RESTRICTED; /* pass 3 mark as allowed */ while ((name = strsep(&val, " ")) && *name) { ca = tcp_ca_find(name); WARN_ON(!ca); if (ca) - ca->non_restricted = 1; + ca->flags |= TCP_CONG_NON_RESTRICTED; } out: spin_unlock(&tcp_cong_list_lock); @@ -256,7 +256,7 @@ int tcp_set_congestion_control(struct sock *sk, const char *name) if (!ca) err = -ENOENT; - else if (!(ca->non_restricted || capable(CAP_NET_ADMIN))) + else if (!((ca->flags & TCP_CONG_NON_RESTRICTED) || capable(CAP_NET_ADMIN))) err = -EPERM; else if (!try_module_get(ca->owner)) @@ -371,8 +371,8 @@ u32 tcp_reno_min_cwnd(const struct sock *sk) EXPORT_SYMBOL_GPL(tcp_reno_min_cwnd); struct tcp_congestion_ops tcp_reno = { + .flags = TCP_CONG_NON_RESTRICTED, .name = "reno", - .non_restricted = 1, .owner = THIS_MODULE, .ssthresh = tcp_reno_ssthresh, .cong_avoid = tcp_reno_cong_avoid, diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c index 296845be912..14224487b16 100644 --- a/net/ipv4/tcp_cubic.c +++ b/net/ipv4/tcp_cubic.c @@ -334,7 +334,7 @@ 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) +static void bictcp_acked(struct sock *sk, u32 cnt, ktime_t last) { const struct inet_connection_sock *icsk = inet_csk(sk); diff --git a/net/ipv4/tcp_htcp.c b/net/ipv4/tcp_htcp.c index 1020eb48d8d..4ba4a7ae0a8 100644 --- a/net/ipv4/tcp_htcp.c +++ b/net/ipv4/tcp_htcp.c @@ -98,7 +98,7 @@ static inline void measure_rtt(struct sock *sk) } } -static void measure_achieved_throughput(struct sock *sk, u32 pkts_acked) +static void measure_achieved_throughput(struct sock *sk, u32 pkts_acked, ktime_t last) { const struct inet_connection_sock *icsk = inet_csk(sk); const struct tcp_sock *tp = tcp_sk(sk); diff --git a/net/ipv4/tcp_illinois.c b/net/ipv4/tcp_illinois.c index ae629860088..8e3165917f7 100644 --- a/net/ipv4/tcp_illinois.c +++ b/net/ipv4/tcp_illinois.c @@ -83,9 +83,14 @@ static void tcp_illinois_init(struct sock *sk) } /* Measure RTT for each ack. */ -static void tcp_illinois_rtt_sample(struct sock *sk, u32 rtt) +static void tcp_illinois_acked(struct sock *sk, u32 pkts_acked, ktime_t last) { struct illinois *ca = inet_csk_ca(sk); + u32 rtt; + + ca->acked = pkts_acked; + + rtt = ktime_to_ns(net_timedelta(last)) / NSEC_PER_USEC; /* ignore bogus values, this prevents wraparound in alpha math */ if (rtt > RTT_MAX) @@ -103,13 +108,6 @@ static void tcp_illinois_rtt_sample(struct sock *sk, u32 rtt) ca->sum_rtt += rtt; } -/* Capture count of packets covered by ack, to adjust for delayed acks */ -static void tcp_illinois_acked(struct sock *sk, u32 pkts_acked) -{ - struct illinois *ca = inet_csk_ca(sk); - ca->acked = pkts_acked; -} - /* Maximum queuing delay */ static inline u32 max_delay(const struct illinois *ca) { @@ -325,12 +323,12 @@ static void tcp_illinois_info(struct sock *sk, u32 ext, } static struct tcp_congestion_ops tcp_illinois = { + .flags = TCP_CONG_RTT_STAMP, .init = tcp_illinois_init, .ssthresh = tcp_illinois_ssthresh, .min_cwnd = tcp_reno_min_cwnd, .cong_avoid = tcp_illinois_cong_avoid, .set_state = tcp_illinois_state, - .rtt_sample = tcp_illinois_rtt_sample, .get_info = tcp_illinois_info, .pkts_acked = tcp_illinois_acked, diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 63338939078..051f0f815f1 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -2402,14 +2402,6 @@ static int tcp_tso_acked(struct sock *sk, struct sk_buff *skb, return acked; } -static u32 tcp_usrtt(struct timeval *tv) -{ - struct timeval now; - - do_gettimeofday(&now); - return (now.tv_sec - tv->tv_sec) * 1000000 + (now.tv_usec - tv->tv_usec); -} - /* Remove acknowledged frames from the retransmission queue. */ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p) { @@ -2420,9 +2412,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p) int acked = 0; __s32 seq_rtt = -1; u32 pkts_acked = 0; - void (*rtt_sample)(struct sock *sk, u32 usrtt) - = icsk->icsk_ca_ops->rtt_sample; - struct timeval tv = { .tv_sec = 0, .tv_usec = 0 }; + ktime_t last_ackt = ktime_set(0,0); while ((skb = tcp_write_queue_head(sk)) && skb != tcp_send_head(sk)) { @@ -2471,7 +2461,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p) seq_rtt = -1; } else if (seq_rtt < 0) { seq_rtt = now - scb->when; - skb_get_timestamp(skb, &tv); + last_ackt = skb->tstamp; } if (sacked & TCPCB_SACKED_ACKED) tp->sacked_out -= tcp_skb_pcount(skb); @@ -2484,7 +2474,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p) } } else if (seq_rtt < 0) { seq_rtt = now - scb->when; - skb_get_timestamp(skb, &tv); + last_ackt = skb->tstamp; } tcp_dec_pcount_approx(&tp->fackets_out, skb); tcp_packets_out_dec(tp, skb); @@ -2494,13 +2484,14 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p) } if (acked&FLAG_ACKED) { + const struct tcp_congestion_ops *ca_ops + = inet_csk(sk)->icsk_ca_ops; + tcp_ack_update_rtt(sk, acked, seq_rtt); tcp_ack_packets_out(sk); - if (rtt_sample && !(acked & FLAG_RETRANS_DATA_ACKED)) - (*rtt_sample)(sk, tcp_usrtt(&tv)); - if (icsk->icsk_ca_ops->pkts_acked) - icsk->icsk_ca_ops->pkts_acked(sk, pkts_acked); + if (ca_ops->pkts_acked) + ca_ops->pkts_acked(sk, pkts_acked, last_ackt); } #if FASTRETRANS_DEBUG > 0 diff --git a/net/ipv4/tcp_lp.c b/net/ipv4/tcp_lp.c index f0ebaf0e21c..b4e062ab24a 100644 --- a/net/ipv4/tcp_lp.c +++ b/net/ipv4/tcp_lp.c @@ -218,7 +218,7 @@ static u32 tcp_lp_owd_calculator(struct sock *sk) * 3. calc smoothed OWD (SOWD). * Most ideas come from the original TCP-LP implementation. */ -static void tcp_lp_rtt_sample(struct sock *sk, u32 usrtt) +static void tcp_lp_rtt_sample(struct sock *sk, u32 rtt) { struct lp *lp = inet_csk_ca(sk); s64 mowd = tcp_lp_owd_calculator(sk); @@ -261,11 +261,13 @@ static void tcp_lp_rtt_sample(struct sock *sk, u32 usrtt) * 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) +static void tcp_lp_pkts_acked(struct sock *sk, u32 num_acked, ktime_t last) { struct tcp_sock *tp = tcp_sk(sk); struct lp *lp = inet_csk_ca(sk); + tcp_lp_rtt_sample(sk, ktime_to_ns(net_timedelta(last)) / NSEC_PER_USEC); + /* calc inference */ if (tcp_time_stamp > tp->rx_opt.rcv_tsecr) lp->inference = 3 * (tcp_time_stamp - tp->rx_opt.rcv_tsecr); @@ -312,11 +314,11 @@ static void tcp_lp_pkts_acked(struct sock *sk, u32 num_acked) } static struct tcp_congestion_ops tcp_lp = { + .flags = TCP_CONG_RTT_STAMP, .init = tcp_lp_init, .ssthresh = tcp_reno_ssthresh, .cong_avoid = tcp_lp_cong_avoid, .min_cwnd = tcp_reno_min_cwnd, - .rtt_sample = tcp_lp_rtt_sample, .pkts_acked = tcp_lp_pkts_acked, .owner = THIS_MODULE, diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 3a60aea744a..e70a6840cb6 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -409,7 +409,7 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it, /* If congestion control is doing timestamping, we must * take such a timestamp before we potentially clone/copy. */ - if (icsk->icsk_ca_ops->rtt_sample) + if (icsk->icsk_ca_ops->flags & TCP_CONG_RTT_STAMP) __net_timestamp(skb); if (likely(clone_it)) { diff --git a/net/ipv4/tcp_vegas.c b/net/ipv4/tcp_vegas.c index 87e72bef6d0..f4104eeb5f2 100644 --- a/net/ipv4/tcp_vegas.c +++ b/net/ipv4/tcp_vegas.c @@ -120,10 +120,13 @@ static void tcp_vegas_init(struct sock *sk) * o min-filter RTT samples from a much longer window (forever for now) * to find the propagation delay (baseRTT) */ -static void tcp_vegas_rtt_calc(struct sock *sk, u32 usrtt) +static void tcp_vegas_pkts_acked(struct sock *sk, u32 cnt, ktime_t last) { struct vegas *vegas = inet_csk_ca(sk); - u32 vrtt = usrtt + 1; /* Never allow zero rtt or baseRTT */ + u32 vrtt; + + /* Never allow zero rtt or baseRTT */ + vrtt = (ktime_to_ns(net_timedelta(last)) / NSEC_PER_USEC) + 1; /* Filter to find propagation delay: */ if (vrtt < vegas->baseRTT) @@ -353,11 +356,12 @@ static void tcp_vegas_get_info(struct sock *sk, u32 ext, } static struct tcp_congestion_ops tcp_vegas = { + .flags = TCP_CONG_RTT_STAMP, .init = tcp_vegas_init, .ssthresh = tcp_reno_ssthresh, .cong_avoid = tcp_vegas_cong_avoid, .min_cwnd = tcp_reno_min_cwnd, - .rtt_sample = tcp_vegas_rtt_calc, + .pkts_acked = tcp_vegas_pkts_acked, .set_state = tcp_vegas_state, .cwnd_event = tcp_vegas_cwnd_event, .get_info = tcp_vegas_get_info, diff --git a/net/ipv4/tcp_veno.c b/net/ipv4/tcp_veno.c index ce57bf302f6..0b50d0607a0 100644 --- a/net/ipv4/tcp_veno.c +++ b/net/ipv4/tcp_veno.c @@ -69,10 +69,13 @@ static void tcp_veno_init(struct sock *sk) } /* Do rtt sampling needed for Veno. */ -static void tcp_veno_rtt_calc(struct sock *sk, u32 usrtt) +static void tcp_veno_pkts_acked(struct sock *sk, u32 cnt, ktime_t last) { struct veno *veno = inet_csk_ca(sk); - u32 vrtt = usrtt + 1; /* Never allow zero rtt or basertt */ + u32 vrtt; + + /* Never allow zero rtt or baseRTT */ + vrtt = (ktime_to_ns(net_timedelta(last)) / NSEC_PER_USEC) + 1; /* Filter to find propagation delay: */ if (vrtt < veno->basertt) @@ -199,10 +202,11 @@ static u32 tcp_veno_ssthresh(struct sock *sk) } static struct tcp_congestion_ops tcp_veno = { + .flags = TCP_CONG_RTT_STAMP, .init = tcp_veno_init, .ssthresh = tcp_veno_ssthresh, .cong_avoid = tcp_veno_cong_avoid, - .rtt_sample = tcp_veno_rtt_calc, + .pkts_acked = tcp_veno_pkts_acked, .set_state = tcp_veno_state, .cwnd_event = tcp_veno_cwnd_event, diff --git a/net/ipv4/tcp_westwood.c b/net/ipv4/tcp_westwood.c index ae1026a6772..e61e09dd513 100644 --- a/net/ipv4/tcp_westwood.c +++ b/net/ipv4/tcp_westwood.c @@ -100,7 +100,7 @@ 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) +static void tcp_westwood_pkts_acked(struct sock *sk, u32 cnt, ktime_t last) { struct westwood *w = inet_csk_ca(sk); if (cnt > 0) diff --git a/net/ipv4/tcp_yeah.c b/net/ipv4/tcp_yeah.c index 46dd1bee583..81ef02c1649 100644 --- a/net/ipv4/tcp_yeah.c +++ b/net/ipv4/tcp_yeah.c @@ -64,13 +64,15 @@ static void tcp_yeah_init(struct sock *sk) } -static void tcp_yeah_pkts_acked(struct sock *sk, u32 pkts_acked) +static void tcp_yeah_pkts_acked(struct sock *sk, u32 pkts_acked, ktime_t last) { 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; + + tcp_vegas_pkts_acked(sk, pkts_acked, last); } static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, @@ -237,11 +239,11 @@ static u32 tcp_yeah_ssthresh(struct sock *sk) { } static struct tcp_congestion_ops tcp_yeah = { + .flags = TCP_CONG_RTT_STAMP, .init = tcp_yeah_init, .ssthresh = tcp_yeah_ssthresh, .cong_avoid = tcp_yeah_cong_avoid, .min_cwnd = tcp_reno_min_cwnd, - .rtt_sample = tcp_vegas_rtt_calc, .set_state = tcp_vegas_state, .cwnd_event = tcp_vegas_cwnd_event, .get_info = tcp_vegas_get_info, diff --git a/net/ipv4/tcp_yeah.h b/net/ipv4/tcp_yeah.h index a62d82038fd..33ad5385c18 100644 --- a/net/ipv4/tcp_yeah.h +++ b/net/ipv4/tcp_yeah.h @@ -81,10 +81,13 @@ static void tcp_vegas_state(struct sock *sk, u8 ca_state) * o min-filter RTT samples from a much longer window (forever for now) * to find the propagation delay (baseRTT) */ -static void tcp_vegas_rtt_calc(struct sock *sk, u32 usrtt) +static void tcp_vegas_pkts_acked(struct sock *sk, u32 cnt, ktime_t last) { struct vegas *vegas = inet_csk_ca(sk); - u32 vrtt = usrtt + 1; /* Never allow zero rtt or baseRTT */ + u32 vrtt; + + /* Never allow zero rtt or baseRTT */ + vrtt = (ktime_to_ns(net_timedelta(last)) / NSEC_PER_USEC) + 1; /* Filter to find propagation delay: */ if (vrtt < vegas->baseRTT) -- 2.20.1