X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=net%2Fipv4%2Ftcp_yeah.c;h=e03b10183a8b86810cc7f33d4bc69815d3c05f7f;hb=061964fb988ca51087948975da66ff523b3a5852;hp=18355a2608e193011c736b517a20fb013db729ff;hpb=3927f2e8f9afa3424bb51ca81f7abac01ffd0005;p=linux-2.6 diff --git a/net/ipv4/tcp_yeah.c b/net/ipv4/tcp_yeah.c index 18355a2608..e03b10183a 100644 --- a/net/ipv4/tcp_yeah.c +++ b/net/ipv4/tcp_yeah.c @@ -6,13 +6,14 @@ * http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf * */ +#include +#include +#include +#include -#include "tcp_yeah.h" +#include -/* Default values of the Vegas variables, in fixed-point representation - * with V_PARAM_SHIFT bits to the right of the binary point. - */ -#define V_PARAM_SHIFT 1 +#include "tcp_vegas.h" #define TCP_YEAH_ALPHA 80 //lin number of packets queued at the bottleneck #define TCP_YEAH_GAMMA 1 //lin fraction of queue to be removed per rtt @@ -26,14 +27,7 @@ /* YeAH variables */ struct yeah { - /* Vegas */ - u32 beg_snd_nxt; /* right edge during last RTT */ - u32 beg_snd_una; /* left edge during last RTT */ - u32 beg_snd_cwnd; /* saves the size of the cwnd */ - u8 doing_vegas_now;/* if true, do vegas for this RTT */ - u16 cntRTT; /* # of RTTs measured within last RTT */ - u32 minRTT; /* min of RTTs measured within last RTT (in usec) */ - u32 baseRTT; /* the min of all Vegas RTT measurements seen (in usec) */ + struct vegas vegas; /* must be first */ /* YeAH */ u32 lastQ; @@ -64,17 +58,18 @@ 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, s32 rtt_us) { 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, rtt_us); } -static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, - u32 seq_rtt, u32 in_flight, int flag) +static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, u32 in_flight) { struct tcp_sock *tp = tcp_sk(sk); struct yeah *yeah = inet_csk_ca(sk); @@ -82,9 +77,10 @@ static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, 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 if (!yeah->doing_reno_now) { + + else if (!yeah->doing_reno_now) { /* Scalable */ tp->snd_cwnd_cnt+=yeah->pkts_acked; @@ -108,19 +104,19 @@ static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, } } - /* The key players are v_beg_snd_una and v_beg_snd_nxt. + /* The key players are v_vegas.beg_snd_una and v_beg_snd_nxt. * * These are so named because they represent the approximate values * of snd_una and snd_nxt at the beginning of the current RTT. More * precisely, they represent the amount of data sent during the RTT. * At the end of the RTT, when we receive an ACK for v_beg_snd_nxt, - * we will calculate that (v_beg_snd_nxt - v_beg_snd_una) outstanding + * we will calculate that (v_beg_snd_nxt - v_vegas.beg_snd_una) outstanding * bytes of data have been ACKed during the course of the RTT, giving * an "actual" rate of: * - * (v_beg_snd_nxt - v_beg_snd_una) / (rtt duration) + * (v_beg_snd_nxt - v_vegas.beg_snd_una) / (rtt duration) * - * Unfortunately, v_beg_snd_una is not exactly equal to snd_una, + * Unfortunately, v_vegas.beg_snd_una is not exactly equal to snd_una, * because delayed ACKs can cover more than one segment, so they * don't line up yeahly with the boundaries of RTTs. * @@ -130,7 +126,7 @@ static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, * So we keep track of our cwnd separately, in v_beg_snd_cwnd. */ - if (after(ack, yeah->beg_snd_nxt)) { + if (after(ack, yeah->vegas.beg_snd_nxt)) { /* We do the Vegas calculations only if we got enough RTT * samples that we can be reasonably sure that we got @@ -141,9 +137,9 @@ static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, * If we have 3 samples, we should be OK. */ - if (yeah->cntRTT > 2) { - u32 rtt; - u32 queue, maxqueue; + if (yeah->vegas.cntRTT > 2) { + u32 rtt, queue; + u64 bw; /* We have enough RTT samples, so, using the Vegas * algorithm, we determine if we should increase or @@ -156,34 +152,38 @@ static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, * of delayed ACKs, at the cost of noticing congestion * a bit later. */ - rtt = yeah->minRTT; - - queue = (u32)div64_64((u64)tp->snd_cwnd * (rtt - yeah->baseRTT), rtt); - - maxqueue = TCP_YEAH_ALPHA; + rtt = yeah->vegas.minRTT; - if (queue > maxqueue || - rtt - yeah->baseRTT > (yeah->baseRTT / TCP_YEAH_PHY)) { - - if (queue > maxqueue && tp->snd_cwnd > yeah->reno_count) { - u32 reduction = min( queue / TCP_YEAH_GAMMA , - tp->snd_cwnd >> TCP_YEAH_EPSILON ); + /* Compute excess number of packets above bandwidth + * Avoid doing full 64 bit divide. + */ + bw = tp->snd_cwnd; + bw *= rtt - yeah->vegas.baseRTT; + do_div(bw, rtt); + queue = bw; + + if (queue > TCP_YEAH_ALPHA || + rtt - yeah->vegas.baseRTT > (yeah->vegas.baseRTT / TCP_YEAH_PHY)) { + if (queue > TCP_YEAH_ALPHA + && tp->snd_cwnd > yeah->reno_count) { + u32 reduction = min(queue / TCP_YEAH_GAMMA , + tp->snd_cwnd >> TCP_YEAH_EPSILON); tp->snd_cwnd -= reduction; - tp->snd_cwnd = max( tp->snd_cwnd, yeah->reno_count); + tp->snd_cwnd = max(tp->snd_cwnd, + yeah->reno_count); tp->snd_ssthresh = tp->snd_cwnd; - } + } if (yeah->reno_count <= 2) - yeah->reno_count = max( tp->snd_cwnd>>1, 2U); + yeah->reno_count = max(tp->snd_cwnd>>1, 2U); else yeah->reno_count++; - yeah->doing_reno_now = - min_t( u32, yeah->doing_reno_now + 1 , 0xffffff); - + yeah->doing_reno_now = min(yeah->doing_reno_now + 1, + 0xffffffU); } else { yeah->fast_count++; @@ -202,13 +202,13 @@ static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, /* Save the extent of the current window so we can use this * at the end of the next RTT. */ - yeah->beg_snd_una = yeah->beg_snd_nxt; - yeah->beg_snd_nxt = tp->snd_nxt; - yeah->beg_snd_cwnd = tp->snd_cwnd; + yeah->vegas.beg_snd_una = yeah->vegas.beg_snd_nxt; + yeah->vegas.beg_snd_nxt = tp->snd_nxt; + yeah->vegas.beg_snd_cwnd = tp->snd_cwnd; /* Wipe the slate clean for the next RTT. */ - yeah->cntRTT = 0; - yeah->minRTT = 0x7fffffff; + yeah->vegas.cntRTT = 0; + yeah->vegas.minRTT = 0x7fffffff; } } @@ -233,11 +233,11 @@ 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,