X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=net%2Fipv4%2Ftcp_htcp.c;h=7c94a49554167a7315c22faf7cbaafa13824c434;hb=becd214277ed41dc6f745f5f8db39d84c6c7ffc8;hp=128de4d7c0b7dd40c95d94b3efdbab73a2e20041;hpb=2c74088e4104a2a82bd773f79ae0344c22eceb8c;p=safe%2Fjmp%2Flinux-2.6 diff --git a/net/ipv4/tcp_htcp.c b/net/ipv4/tcp_htcp.c index 128de4d..7c94a49 100644 --- a/net/ipv4/tcp_htcp.c +++ b/net/ipv4/tcp_htcp.c @@ -6,33 +6,33 @@ * http://www.hamilton.ie/net/htcp3.pdf */ -#include #include #include #include -#define ALPHA_BASE (1<<7) /* 1.0 with shift << 7 */ -#define BETA_MIN (1<<6) /* 0.5 with shift << 7 */ +#define ALPHA_BASE (1<<7) /* 1.0 with shift << 7 */ +#define BETA_MIN (1<<6) /* 0.5 with shift << 7 */ #define BETA_MAX 102 /* 0.8 with shift << 7 */ -static int use_rtt_scaling = 1; +static int use_rtt_scaling __read_mostly = 1; module_param(use_rtt_scaling, int, 0644); MODULE_PARM_DESC(use_rtt_scaling, "turn on/off RTT scaling"); -static int use_bandwidth_switch = 1; +static int use_bandwidth_switch __read_mostly = 1; module_param(use_bandwidth_switch, int, 0644); MODULE_PARM_DESC(use_bandwidth_switch, "turn on/off bandwidth switcher"); struct htcp { - u16 alpha; /* Fixed point arith, << 7 */ + u32 alpha; /* Fixed point arith, << 7 */ u8 beta; /* Fixed point arith, << 7 */ - u8 modeswitch; /* Delay modeswitch until we had at least one congestion event */ - u8 ccount; /* Number of RTTs since last congestion event */ - u8 undo_ccount; - u16 packetcount; + u8 modeswitch; /* Delay modeswitch + until we had at least one congestion event */ + u16 pkts_acked; + u32 packetcount; u32 minRTT; u32 maxRTT; - u32 snd_cwnd_cnt2; + u32 last_cong; /* Time since last congestion event end */ + u32 undo_last_cong; u32 undo_maxRTT; u32 undo_old_maxB; @@ -45,56 +45,77 @@ struct htcp { u32 lasttime; }; +static inline u32 htcp_cong_time(const struct htcp *ca) +{ + return jiffies - ca->last_cong; +} + +static inline u32 htcp_ccount(const struct htcp *ca) +{ + return htcp_cong_time(ca) / ca->minRTT; +} + static inline void htcp_reset(struct htcp *ca) { - ca->undo_ccount = ca->ccount; + ca->undo_last_cong = ca->last_cong; ca->undo_maxRTT = ca->maxRTT; ca->undo_old_maxB = ca->old_maxB; - ca->ccount = 0; - ca->snd_cwnd_cnt2 = 0; + ca->last_cong = jiffies; } static u32 htcp_cwnd_undo(struct sock *sk) { const struct tcp_sock *tp = tcp_sk(sk); struct htcp *ca = inet_csk_ca(sk); - ca->ccount = ca->undo_ccount; - ca->maxRTT = ca->undo_maxRTT; - ca->old_maxB = ca->undo_old_maxB; - return max(tp->snd_cwnd, (tp->snd_ssthresh<<7)/ca->beta); + + if (ca->undo_last_cong) { + ca->last_cong = ca->undo_last_cong; + ca->maxRTT = ca->undo_maxRTT; + ca->old_maxB = ca->undo_old_maxB; + ca->undo_last_cong = 0; + } + + return max(tp->snd_cwnd, (tp->snd_ssthresh << 7) / ca->beta); } -static inline void measure_rtt(struct sock *sk) +static inline void measure_rtt(struct sock *sk, u32 srtt) { const struct inet_connection_sock *icsk = inet_csk(sk); - const struct tcp_sock *tp = tcp_sk(sk); struct htcp *ca = inet_csk_ca(sk); - u32 srtt = tp->srtt>>3; /* keep track of minimum RTT seen so far, minRTT is zero at first */ if (ca->minRTT > srtt || !ca->minRTT) ca->minRTT = srtt; /* max RTT */ - if (icsk->icsk_ca_state == TCP_CA_Open && tp->snd_ssthresh < 0xFFFF && ca->ccount > 3) { + if (icsk->icsk_ca_state == TCP_CA_Open) { if (ca->maxRTT < ca->minRTT) ca->maxRTT = ca->minRTT; - if (ca->maxRTT < srtt && srtt <= ca->maxRTT+HZ/50) + if (ca->maxRTT < srtt && + srtt <= ca->maxRTT + msecs_to_jiffies(20)) ca->maxRTT = srtt; } } -static void measure_achieved_throughput(struct sock *sk, u32 pkts_acked) +static void measure_achieved_throughput(struct sock *sk, u32 pkts_acked, s32 rtt) { const struct inet_connection_sock *icsk = inet_csk(sk); const struct tcp_sock *tp = tcp_sk(sk); struct htcp *ca = inet_csk_ca(sk); u32 now = tcp_time_stamp; + if (icsk->icsk_ca_state == TCP_CA_Open) + ca->pkts_acked = pkts_acked; + + if (rtt > 0) + measure_rtt(sk, usecs_to_jiffies(rtt)); + + if (!use_bandwidth_switch) + return; + /* achieved throughput calculations */ - if (icsk->icsk_ca_state != TCP_CA_Open && - icsk->icsk_ca_state != TCP_CA_Disorder) { + if (!((1 << icsk->icsk_ca_state) & (TCPF_CA_Open | TCPF_CA_Disorder))) { ca->packetcount = 0; ca->lasttime = now; return; @@ -102,15 +123,16 @@ static void measure_achieved_throughput(struct sock *sk, u32 pkts_acked) ca->packetcount += pkts_acked; - if (ca->packetcount >= tp->snd_cwnd - (ca->alpha>>7? : 1) - && now - ca->lasttime >= ca->minRTT - && ca->minRTT > 0) { - __u32 cur_Bi = ca->packetcount*HZ/(now - ca->lasttime); - if (ca->ccount <= 3) { + if (ca->packetcount >= tp->snd_cwnd - (ca->alpha >> 7 ? : 1) && + now - ca->lasttime >= ca->minRTT && + ca->minRTT > 0) { + __u32 cur_Bi = ca->packetcount * HZ / (now - ca->lasttime); + + if (htcp_ccount(ca) <= 3) { /* just after backoff */ ca->minB = ca->maxB = ca->Bi = cur_Bi; } else { - ca->Bi = (3*ca->Bi + cur_Bi)/4; + ca->Bi = (3 * ca->Bi + cur_Bi) / 4; if (ca->Bi > ca->maxB) ca->maxB = ca->Bi; if (ca->minB > ca->maxB) @@ -128,15 +150,15 @@ static inline void htcp_beta_update(struct htcp *ca, u32 minRTT, u32 maxRTT) u32 old_maxB = ca->old_maxB; ca->old_maxB = ca->maxB; - if (!between(5*maxB, 4*old_maxB, 6*old_maxB)) { + if (!between(5 * maxB, 4 * old_maxB, 6 * old_maxB)) { ca->beta = BETA_MIN; ca->modeswitch = 0; return; } } - if (ca->modeswitch && minRTT > max(HZ/100, 1) && maxRTT) { - ca->beta = (minRTT<<7)/maxRTT; + if (ca->modeswitch && minRTT > msecs_to_jiffies(10) && maxRTT) { + ca->beta = (minRTT << 7) / maxRTT; if (ca->beta < BETA_MIN) ca->beta = BETA_MIN; else if (ca->beta > BETA_MAX) @@ -151,27 +173,30 @@ static inline void htcp_alpha_update(struct htcp *ca) { u32 minRTT = ca->minRTT; u32 factor = 1; - u32 diff = ca->ccount * minRTT; /* time since last backoff */ + u32 diff = htcp_cong_time(ca); if (diff > HZ) { diff -= HZ; - factor = 1+ ( 10*diff + ((diff/2)*(diff/2)/HZ) )/HZ; + factor = 1 + (10 * diff + ((diff / 2) * (diff / 2) / HZ)) / HZ; } if (use_rtt_scaling && minRTT) { - u32 scale = (HZ<<3)/(10*minRTT); - scale = min(max(scale, 1U<<2), 10U<<3); /* clamping ratio to interval [0.5,10]<<3 */ - factor = (factor<<3)/scale; + u32 scale = (HZ << 3) / (10 * minRTT); + + /* clamping ratio to interval [0.5,10]<<3 */ + scale = min(max(scale, 1U << 2), 10U << 3); + factor = (factor << 3) / scale; if (!factor) factor = 1; } - ca->alpha = 2*factor*((1<<7)-ca->beta); + ca->alpha = 2 * factor * ((1 << 7) - ca->beta); if (!ca->alpha) ca->alpha = ALPHA_BASE; } -/* After we have the rtt data to calculate beta, we'd still prefer to wait one +/* + * After we have the rtt data to calculate beta, we'd still prefer to wait one * rtt before we adjust our beta to ensure we are working from a consistent * data. * @@ -188,21 +213,21 @@ static void htcp_param_update(struct sock *sk) htcp_beta_update(ca, minRTT, maxRTT); htcp_alpha_update(ca); - /* add slowly fading memory for maxRTT to accommodate routing changes etc */ + /* add slowly fading memory for maxRTT to accommodate routing changes */ if (minRTT > 0 && maxRTT > minRTT) - ca->maxRTT = minRTT + ((maxRTT-minRTT)*95)/100; + ca->maxRTT = minRTT + ((maxRTT - minRTT) * 95) / 100; } static u32 htcp_recalc_ssthresh(struct sock *sk) { const struct tcp_sock *tp = tcp_sk(sk); const struct htcp *ca = inet_csk_ca(sk); + htcp_param_update(sk); return max((tp->snd_cwnd * ca->beta) >> 7, 2U); } -static void htcp_cong_avoid(struct sock *sk, u32 ack, u32 rtt, - u32 in_flight, int data_acked) +static void htcp_cong_avoid(struct sock *sk, u32 ack, u32 in_flight) { struct tcp_sock *tp = tcp_sk(sk); struct htcp *ca = inet_csk_ca(sk); @@ -210,38 +235,24 @@ static void htcp_cong_avoid(struct sock *sk, u32 ack, u32 rtt, if (!tcp_is_cwnd_limited(sk, in_flight)) return; - if (tp->snd_cwnd <= tp->snd_ssthresh) + if (tp->snd_cwnd <= tp->snd_ssthresh) tcp_slow_start(tp); else { - - measure_rtt(sk); - - /* keep track of number of round-trip times since last backoff event */ - if (ca->snd_cwnd_cnt2++ > tp->snd_cwnd) { - ca->ccount++; - ca->snd_cwnd_cnt2 = 0; - htcp_alpha_update(ca); - } - /* In dangerous area, increase slowly. * In theory this is tp->snd_cwnd += alpha / tp->snd_cwnd */ - if ((tp->snd_cwnd_cnt++ * ca->alpha)>>7 >= tp->snd_cwnd) { + if ((tp->snd_cwnd_cnt * ca->alpha)>>7 >= tp->snd_cwnd) { if (tp->snd_cwnd < tp->snd_cwnd_clamp) tp->snd_cwnd++; tp->snd_cwnd_cnt = 0; - } - } -} + htcp_alpha_update(ca); + } else + tp->snd_cwnd_cnt += ca->pkts_acked; -/* Lower bound on congestion window. */ -static u32 htcp_min_cwnd(struct sock *sk) -{ - const struct tcp_sock *tp = tcp_sk(sk); - return tp->snd_ssthresh; + ca->pkts_acked = 1; + } } - static void htcp_init(struct sock *sk) { struct htcp *ca = inet_csk_ca(sk); @@ -249,11 +260,22 @@ static void htcp_init(struct sock *sk) memset(ca, 0, sizeof(struct htcp)); ca->alpha = ALPHA_BASE; ca->beta = BETA_MIN; + ca->pkts_acked = 1; + ca->last_cong = jiffies; } static void htcp_state(struct sock *sk, u8 new_state) { switch (new_state) { + case TCP_CA_Open: + { + struct htcp *ca = inet_csk_ca(sk); + if (ca->undo_last_cong) { + ca->last_cong = jiffies; + ca->undo_last_cong = 0; + } + } + break; case TCP_CA_CWR: case TCP_CA_Recovery: case TCP_CA_Loss: @@ -265,7 +287,6 @@ static void htcp_state(struct sock *sk, u8 new_state) static struct tcp_congestion_ops htcp = { .init = htcp_init, .ssthresh = htcp_recalc_ssthresh, - .min_cwnd = htcp_min_cwnd, .cong_avoid = htcp_cong_avoid, .set_state = htcp_state, .undo_cwnd = htcp_cwnd_undo, @@ -276,10 +297,8 @@ static struct tcp_congestion_ops htcp = { static int __init htcp_register(void) { - BUG_ON(sizeof(struct htcp) > ICSK_CA_PRIV_SIZE); + BUILD_BUG_ON(sizeof(struct htcp) > ICSK_CA_PRIV_SIZE); BUILD_BUG_ON(BETA_MIN >= BETA_MAX); - if (!use_bandwidth_switch) - htcp.pkts_acked = NULL; return tcp_register_congestion_control(&htcp); }