diff options
Diffstat (limited to 'net/ipv4/tcp_cubic.c')
| -rw-r--r-- | net/ipv4/tcp_cubic.c | 41 |
1 files changed, 23 insertions, 18 deletions
diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c index 34340c9c95f..a9bd8a4828a 100644 --- a/net/ipv4/tcp_cubic.c +++ b/net/ipv4/tcp_cubic.c @@ -93,6 +93,7 @@ struct bictcp { u32 ack_cnt; /* number of acks */ u32 tcp_cwnd; /* estimated tcp cwnd */ #define ACK_RATIO_SHIFT 4 +#define ACK_RATIO_LIMIT (32u << ACK_RATIO_SHIFT) u16 delayed_ack; /* estimate the ratio of Packets/ACKs << 4 */ u8 sample_cnt; /* number of samples to decide curr_rtt */ u8 found; /* the exit point is found? */ @@ -106,7 +107,6 @@ static inline void bictcp_reset(struct bictcp *ca) { ca->cnt = 0; ca->last_max_cwnd = 0; - ca->loss_cwnd = 0; ca->last_cwnd = 0; ca->last_time = 0; ca->bic_origin_point = 0; @@ -141,7 +141,10 @@ static inline void bictcp_hystart_reset(struct sock *sk) static void bictcp_init(struct sock *sk) { - bictcp_reset(inet_csk_ca(sk)); + struct bictcp *ca = inet_csk_ca(sk); + + bictcp_reset(ca); + ca->loss_cwnd = 0; if (hystart) bictcp_hystart_reset(sk); @@ -203,8 +206,8 @@ static u32 cubic_root(u64 a) */ static inline void bictcp_update(struct bictcp *ca, u32 cwnd) { - u64 offs; - u32 delta, t, bic_target, max_cnt; + u32 delta, bic_target, max_cnt; + u64 offs, t; ca->ack_cnt++; /* count the number of ACKs */ @@ -247,9 +250,11 @@ static inline void bictcp_update(struct bictcp *ca, u32 cwnd) * if the cwnd < 1 million packets !!! */ + t = (s32)(tcp_time_stamp - ca->epoch_start); + t += msecs_to_jiffies(ca->delay_min >> 3); /* change the unit from HZ to bictcp_HZ */ - t = ((tcp_time_stamp + msecs_to_jiffies(ca->delay_min>>3) - - ca->epoch_start) << BICTCP_HZ) / HZ; + t <<= BICTCP_HZ; + do_div(t, HZ); if (t < ca->bic_K) /* t - K */ offs = ca->bic_K - t; @@ -274,7 +279,7 @@ static inline void bictcp_update(struct bictcp *ca, u32 cwnd) * The initial growth of cubic function may be too conservative * when the available bandwidth is still unknown. */ - if (ca->loss_cwnd == 0 && ca->cnt > 20) + if (ca->last_max_cwnd == 0 && ca->cnt > 20) ca->cnt = 20; /* increase cwnd 5% per RTT */ /* TCP Friendly */ @@ -299,18 +304,18 @@ static inline void bictcp_update(struct bictcp *ca, u32 cwnd) ca->cnt = 1; } -static void bictcp_cong_avoid(struct sock *sk, u32 ack, u32 in_flight) +static void bictcp_cong_avoid(struct sock *sk, u32 ack, u32 acked) { struct tcp_sock *tp = tcp_sk(sk); struct bictcp *ca = inet_csk_ca(sk); - if (!tcp_is_cwnd_limited(sk, in_flight)) + if (!tcp_is_cwnd_limited(sk)) return; if (tp->snd_cwnd <= tp->snd_ssthresh) { if (hystart && after(ack, ca->end_seq)) bictcp_hystart_reset(sk); - tcp_slow_start(tp); + tcp_slow_start(tp, acked); } else { bictcp_update(ca, tp->snd_cwnd); tcp_cong_avoid_ai(tp, ca->cnt); @@ -341,7 +346,7 @@ static u32 bictcp_undo_cwnd(struct sock *sk) { struct bictcp *ca = inet_csk_ca(sk); - return max(tcp_sk(sk)->snd_cwnd, ca->last_max_cwnd); + return max(tcp_sk(sk)->snd_cwnd, ca->loss_cwnd); } static void bictcp_state(struct sock *sk, u8 new_state) @@ -398,8 +403,12 @@ static void bictcp_acked(struct sock *sk, u32 cnt, s32 rtt_us) u32 delay; if (icsk->icsk_ca_state == TCP_CA_Open) { - cnt -= ca->delayed_ack >> ACK_RATIO_SHIFT; - ca->delayed_ack += cnt; + u32 ratio = ca->delayed_ack; + + ratio -= ca->delayed_ack >> ACK_RATIO_SHIFT; + ratio += cnt; + + ca->delayed_ack = clamp(ratio, 1U, ACK_RATIO_LIMIT); } /* Some calls are for duplicates without timetamps */ @@ -407,7 +416,7 @@ static void bictcp_acked(struct sock *sk, u32 cnt, s32 rtt_us) return; /* Discard delay samples right after fast recovery */ - if ((s32)(tcp_time_stamp - ca->epoch_start) < HZ) + if (ca->epoch_start && (s32)(tcp_time_stamp - ca->epoch_start) < HZ) return; delay = (rtt_us << 3) / USEC_PER_MSEC; @@ -466,10 +475,6 @@ static int __init cubictcp_register(void) /* divide by bic_scale and by constant Srtt (100ms) */ do_div(cube_factor, bic_scale * 10); - /* hystart needs ms clock resolution */ - if (hystart && HZ < 1000) - cubictcp.flags |= TCP_CONG_RTT_STAMP; - return tcp_register_congestion_control(&cubictcp); } |