Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 1 | /* |
| 2 | * TCP CUBIC: Binary Increase Congestion control for TCP v2.0 |
| 3 | * |
| 4 | * This is from the implementation of CUBIC TCP in |
| 5 | * Injong Rhee, Lisong Xu. |
| 6 | * "CUBIC: A New TCP-Friendly High-Speed TCP Variant |
| 7 | * in PFLDnet 2005 |
| 8 | * Available from: |
| 9 | * http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf |
| 10 | * |
| 11 | * Unless CUBIC is enabled and congestion window is large |
| 12 | * this behaves the same as the original Reno. |
| 13 | */ |
| 14 | |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 15 | #include <linux/mm.h> |
| 16 | #include <linux/module.h> |
| 17 | #include <net/tcp.h> |
Stephen Hemminger | 89b3d9a | 2005-12-21 19:32:08 -0800 | [diff] [blame] | 18 | #include <asm/div64.h> |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 19 | |
| 20 | #define BICTCP_BETA_SCALE 1024 /* Scale factor beta calculation |
| 21 | * max_cwnd = snd_cwnd * beta |
| 22 | */ |
| 23 | #define BICTCP_B 4 /* |
| 24 | * In binary search, |
| 25 | * go to point (max+min)/N |
| 26 | */ |
| 27 | #define BICTCP_HZ 10 /* BIC HZ 2^10 = 1024 */ |
| 28 | |
| 29 | static int fast_convergence = 1; |
| 30 | static int max_increment = 16; |
| 31 | static int beta = 819; /* = 819/1024 (BICTCP_BETA_SCALE) */ |
| 32 | static int initial_ssthresh = 100; |
| 33 | static int bic_scale = 41; |
| 34 | static int tcp_friendliness = 1; |
| 35 | |
Stephen Hemminger | 89b3d9a | 2005-12-21 19:32:08 -0800 | [diff] [blame] | 36 | static u32 cube_rtt_scale; |
| 37 | static u32 beta_scale; |
| 38 | static u64 cube_factor; |
| 39 | |
| 40 | /* Note parameters that are used for precomputing scale factors are read-only */ |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 41 | module_param(fast_convergence, int, 0644); |
| 42 | MODULE_PARM_DESC(fast_convergence, "turn on/off fast convergence"); |
| 43 | module_param(max_increment, int, 0644); |
| 44 | MODULE_PARM_DESC(max_increment, "Limit on increment allowed during binary search"); |
Stephen Hemminger | 89b3d9a | 2005-12-21 19:32:08 -0800 | [diff] [blame] | 45 | module_param(beta, int, 0444); |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 46 | MODULE_PARM_DESC(beta, "beta for multiplicative increase"); |
| 47 | module_param(initial_ssthresh, int, 0644); |
| 48 | MODULE_PARM_DESC(initial_ssthresh, "initial value of slow start threshold"); |
Stephen Hemminger | 89b3d9a | 2005-12-21 19:32:08 -0800 | [diff] [blame] | 49 | module_param(bic_scale, int, 0444); |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 50 | MODULE_PARM_DESC(bic_scale, "scale (scaled by 1024) value for bic function (bic_scale/1024)"); |
| 51 | module_param(tcp_friendliness, int, 0644); |
| 52 | MODULE_PARM_DESC(tcp_friendliness, "turn on/off tcp friendliness"); |
| 53 | |
Stephen Hemminger | 9eb2d62 | 2005-12-21 19:32:36 -0800 | [diff] [blame] | 54 | #include <asm/div64.h> |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 55 | |
| 56 | /* BIC TCP Parameters */ |
| 57 | struct bictcp { |
| 58 | u32 cnt; /* increase cwnd by 1 after ACKs */ |
| 59 | u32 last_max_cwnd; /* last maximum snd_cwnd */ |
| 60 | u32 loss_cwnd; /* congestion window at last loss */ |
| 61 | u32 last_cwnd; /* the last snd_cwnd */ |
| 62 | u32 last_time; /* time when updated last_cwnd */ |
| 63 | u32 bic_origin_point;/* origin point of bic function */ |
| 64 | u32 bic_K; /* time to origin point from the beginning of the current epoch */ |
| 65 | u32 delay_min; /* min delay */ |
| 66 | u32 epoch_start; /* beginning of an epoch */ |
| 67 | u32 ack_cnt; /* number of acks */ |
| 68 | u32 tcp_cwnd; /* estimated tcp cwnd */ |
| 69 | #define ACK_RATIO_SHIFT 4 |
| 70 | u32 delayed_ack; /* estimate the ratio of Packets/ACKs << 4 */ |
| 71 | }; |
| 72 | |
| 73 | static inline void bictcp_reset(struct bictcp *ca) |
| 74 | { |
| 75 | ca->cnt = 0; |
| 76 | ca->last_max_cwnd = 0; |
| 77 | ca->loss_cwnd = 0; |
| 78 | ca->last_cwnd = 0; |
| 79 | ca->last_time = 0; |
| 80 | ca->bic_origin_point = 0; |
| 81 | ca->bic_K = 0; |
| 82 | ca->delay_min = 0; |
| 83 | ca->epoch_start = 0; |
| 84 | ca->delayed_ack = 2 << ACK_RATIO_SHIFT; |
| 85 | ca->ack_cnt = 0; |
| 86 | ca->tcp_cwnd = 0; |
| 87 | } |
| 88 | |
| 89 | static void bictcp_init(struct sock *sk) |
| 90 | { |
| 91 | bictcp_reset(inet_csk_ca(sk)); |
| 92 | if (initial_ssthresh) |
| 93 | tcp_sk(sk)->snd_ssthresh = initial_ssthresh; |
| 94 | } |
| 95 | |
Stephen Hemminger | 9eb2d62 | 2005-12-21 19:32:36 -0800 | [diff] [blame] | 96 | /* 64bit divisor, dividend and result. dynamic precision */ |
| 97 | static inline u_int64_t div64_64(u_int64_t dividend, u_int64_t divisor) |
| 98 | { |
| 99 | u_int32_t d = divisor; |
| 100 | |
| 101 | if (divisor > 0xffffffffULL) { |
| 102 | unsigned int shift = fls(divisor >> 32); |
| 103 | |
| 104 | d = divisor >> shift; |
| 105 | dividend >>= shift; |
| 106 | } |
| 107 | |
| 108 | /* avoid 64 bit division if possible */ |
| 109 | if (dividend >> 32) |
| 110 | do_div(dividend, d); |
| 111 | else |
| 112 | dividend = (uint32_t) dividend / d; |
| 113 | |
| 114 | return dividend; |
| 115 | } |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 116 | |
| 117 | /* |
Stephen Hemminger | 9eb2d62 | 2005-12-21 19:32:36 -0800 | [diff] [blame] | 118 | * calculate the cubic root of x using Newton-Raphson |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 119 | */ |
Stephen Hemminger | 9eb2d62 | 2005-12-21 19:32:36 -0800 | [diff] [blame] | 120 | static u32 cubic_root(u64 a) |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 121 | { |
Stephen Hemminger | 9eb2d62 | 2005-12-21 19:32:36 -0800 | [diff] [blame] | 122 | u32 x, x1; |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 123 | |
Stephen Hemminger | 9eb2d62 | 2005-12-21 19:32:36 -0800 | [diff] [blame] | 124 | /* Initial estimate is based on: |
| 125 | * cbrt(x) = exp(log(x) / 3) |
| 126 | */ |
| 127 | x = 1u << (fls64(a)/3); |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 128 | |
Stephen Hemminger | 9eb2d62 | 2005-12-21 19:32:36 -0800 | [diff] [blame] | 129 | /* |
| 130 | * Iteration based on: |
| 131 | * 2 |
| 132 | * x = ( 2 * x + a / x ) / 3 |
| 133 | * k+1 k k |
| 134 | */ |
| 135 | do { |
| 136 | x1 = x; |
| 137 | x = (2 * x + (uint32_t) div64_64(a, x*x)) / 3; |
| 138 | } while (abs(x1 - x) > 1); |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 139 | |
Stephen Hemminger | 9eb2d62 | 2005-12-21 19:32:36 -0800 | [diff] [blame] | 140 | return x; |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 141 | } |
| 142 | |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 143 | /* |
| 144 | * Compute congestion window to use. |
| 145 | */ |
| 146 | static inline void bictcp_update(struct bictcp *ca, u32 cwnd) |
| 147 | { |
Stephen Hemminger | 89b3d9a | 2005-12-21 19:32:08 -0800 | [diff] [blame] | 148 | u64 offs; |
| 149 | u32 delta, t, bic_target, min_cnt, max_cnt; |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 150 | |
| 151 | ca->ack_cnt++; /* count the number of ACKs */ |
| 152 | |
| 153 | if (ca->last_cwnd == cwnd && |
| 154 | (s32)(tcp_time_stamp - ca->last_time) <= HZ / 32) |
| 155 | return; |
| 156 | |
| 157 | ca->last_cwnd = cwnd; |
| 158 | ca->last_time = tcp_time_stamp; |
| 159 | |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 160 | if (ca->epoch_start == 0) { |
| 161 | ca->epoch_start = tcp_time_stamp; /* record the beginning of an epoch */ |
| 162 | ca->ack_cnt = 1; /* start counting */ |
| 163 | ca->tcp_cwnd = cwnd; /* syn with cubic */ |
| 164 | |
| 165 | if (ca->last_max_cwnd <= cwnd) { |
| 166 | ca->bic_K = 0; |
| 167 | ca->bic_origin_point = cwnd; |
| 168 | } else { |
Stephen Hemminger | 89b3d9a | 2005-12-21 19:32:08 -0800 | [diff] [blame] | 169 | /* Compute new K based on |
| 170 | * (wmax-cwnd) * (srtt>>3 / HZ) / c * 2^(3*bictcp_HZ) |
| 171 | */ |
| 172 | ca->bic_K = cubic_root(cube_factor |
| 173 | * (ca->last_max_cwnd - cwnd)); |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 174 | ca->bic_origin_point = ca->last_max_cwnd; |
| 175 | } |
| 176 | } |
| 177 | |
| 178 | /* cubic function - calc*/ |
| 179 | /* calculate c * time^3 / rtt, |
| 180 | * while considering overflow in calculation of time^3 |
Stephen Hemminger | 89b3d9a | 2005-12-21 19:32:08 -0800 | [diff] [blame] | 181 | * (so time^3 is done by using 64 bit) |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 182 | * and without the support of division of 64bit numbers |
Stephen Hemminger | 89b3d9a | 2005-12-21 19:32:08 -0800 | [diff] [blame] | 183 | * (so all divisions are done by using 32 bit) |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 184 | * also NOTE the unit of those veriables |
| 185 | * time = (t - K) / 2^bictcp_HZ |
| 186 | * c = bic_scale >> 10 |
| 187 | * rtt = (srtt >> 3) / HZ |
| 188 | * !!! The following code does not have overflow problems, |
| 189 | * if the cwnd < 1 million packets !!! |
| 190 | */ |
| 191 | |
| 192 | /* change the unit from HZ to bictcp_HZ */ |
| 193 | t = ((tcp_time_stamp + ca->delay_min - ca->epoch_start) |
| 194 | << BICTCP_HZ) / HZ; |
| 195 | |
| 196 | if (t < ca->bic_K) /* t - K */ |
Stephen Hemminger | 89b3d9a | 2005-12-21 19:32:08 -0800 | [diff] [blame] | 197 | offs = ca->bic_K - t; |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 198 | else |
Stephen Hemminger | 89b3d9a | 2005-12-21 19:32:08 -0800 | [diff] [blame] | 199 | offs = t - ca->bic_K; |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 200 | |
Stephen Hemminger | 89b3d9a | 2005-12-21 19:32:08 -0800 | [diff] [blame] | 201 | /* c/rtt * (t-K)^3 */ |
| 202 | delta = (cube_rtt_scale * offs * offs * offs) >> (10+3*BICTCP_HZ); |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 203 | if (t < ca->bic_K) /* below origin*/ |
Stephen Hemminger | 89b3d9a | 2005-12-21 19:32:08 -0800 | [diff] [blame] | 204 | bic_target = ca->bic_origin_point - delta; |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 205 | else /* above origin*/ |
Stephen Hemminger | 89b3d9a | 2005-12-21 19:32:08 -0800 | [diff] [blame] | 206 | bic_target = ca->bic_origin_point + delta; |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 207 | |
| 208 | /* cubic function - calc bictcp_cnt*/ |
| 209 | if (bic_target > cwnd) { |
| 210 | ca->cnt = cwnd / (bic_target - cwnd); |
| 211 | } else { |
| 212 | ca->cnt = 100 * cwnd; /* very small increment*/ |
| 213 | } |
| 214 | |
| 215 | if (ca->delay_min > 0) { |
| 216 | /* max increment = Smax * rtt / 0.1 */ |
| 217 | min_cnt = (cwnd * HZ * 8)/(10 * max_increment * ca->delay_min); |
| 218 | if (ca->cnt < min_cnt) |
| 219 | ca->cnt = min_cnt; |
| 220 | } |
| 221 | |
| 222 | /* slow start and low utilization */ |
| 223 | if (ca->loss_cwnd == 0) /* could be aggressive in slow start */ |
| 224 | ca->cnt = 50; |
| 225 | |
| 226 | /* TCP Friendly */ |
| 227 | if (tcp_friendliness) { |
Stephen Hemminger | 89b3d9a | 2005-12-21 19:32:08 -0800 | [diff] [blame] | 228 | u32 scale = beta_scale; |
| 229 | delta = (cwnd * scale) >> 3; |
| 230 | while (ca->ack_cnt > delta) { /* update tcp cwnd */ |
| 231 | ca->ack_cnt -= delta; |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 232 | ca->tcp_cwnd++; |
| 233 | } |
| 234 | |
| 235 | if (ca->tcp_cwnd > cwnd){ /* if bic is slower than tcp */ |
Stephen Hemminger | 89b3d9a | 2005-12-21 19:32:08 -0800 | [diff] [blame] | 236 | delta = ca->tcp_cwnd - cwnd; |
| 237 | max_cnt = cwnd / delta; |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 238 | if (ca->cnt > max_cnt) |
| 239 | ca->cnt = max_cnt; |
| 240 | } |
| 241 | } |
| 242 | |
| 243 | ca->cnt = (ca->cnt << ACK_RATIO_SHIFT) / ca->delayed_ack; |
| 244 | if (ca->cnt == 0) /* cannot be zero */ |
| 245 | ca->cnt = 1; |
| 246 | } |
| 247 | |
| 248 | |
| 249 | /* Keep track of minimum rtt */ |
| 250 | static inline void measure_delay(struct sock *sk) |
| 251 | { |
| 252 | const struct tcp_sock *tp = tcp_sk(sk); |
| 253 | struct bictcp *ca = inet_csk_ca(sk); |
| 254 | u32 delay; |
| 255 | |
| 256 | /* No time stamp */ |
| 257 | if (!(tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr) || |
| 258 | /* Discard delay samples right after fast recovery */ |
| 259 | (s32)(tcp_time_stamp - ca->epoch_start) < HZ) |
| 260 | return; |
| 261 | |
| 262 | delay = tcp_time_stamp - tp->rx_opt.rcv_tsecr; |
| 263 | if (delay == 0) |
| 264 | delay = 1; |
| 265 | |
| 266 | /* first time call or link delay decreases */ |
| 267 | if (ca->delay_min == 0 || ca->delay_min > delay) |
| 268 | ca->delay_min = delay; |
| 269 | } |
| 270 | |
| 271 | static void bictcp_cong_avoid(struct sock *sk, u32 ack, |
| 272 | u32 seq_rtt, u32 in_flight, int data_acked) |
| 273 | { |
| 274 | struct tcp_sock *tp = tcp_sk(sk); |
| 275 | struct bictcp *ca = inet_csk_ca(sk); |
| 276 | |
| 277 | if (data_acked) |
| 278 | measure_delay(sk); |
| 279 | |
| 280 | if (!tcp_is_cwnd_limited(sk, in_flight)) |
| 281 | return; |
| 282 | |
| 283 | if (tp->snd_cwnd <= tp->snd_ssthresh) |
| 284 | tcp_slow_start(tp); |
| 285 | else { |
| 286 | bictcp_update(ca, tp->snd_cwnd); |
| 287 | |
| 288 | /* In dangerous area, increase slowly. |
| 289 | * In theory this is tp->snd_cwnd += 1 / tp->snd_cwnd |
| 290 | */ |
| 291 | if (tp->snd_cwnd_cnt >= ca->cnt) { |
| 292 | if (tp->snd_cwnd < tp->snd_cwnd_clamp) |
| 293 | tp->snd_cwnd++; |
| 294 | tp->snd_cwnd_cnt = 0; |
| 295 | } else |
| 296 | tp->snd_cwnd_cnt++; |
| 297 | } |
| 298 | |
| 299 | } |
| 300 | |
| 301 | static u32 bictcp_recalc_ssthresh(struct sock *sk) |
| 302 | { |
| 303 | const struct tcp_sock *tp = tcp_sk(sk); |
| 304 | struct bictcp *ca = inet_csk_ca(sk); |
| 305 | |
| 306 | ca->epoch_start = 0; /* end of epoch */ |
| 307 | |
| 308 | /* Wmax and fast convergence */ |
| 309 | if (tp->snd_cwnd < ca->last_max_cwnd && fast_convergence) |
| 310 | ca->last_max_cwnd = (tp->snd_cwnd * (BICTCP_BETA_SCALE + beta)) |
| 311 | / (2 * BICTCP_BETA_SCALE); |
| 312 | else |
| 313 | ca->last_max_cwnd = tp->snd_cwnd; |
| 314 | |
| 315 | ca->loss_cwnd = tp->snd_cwnd; |
| 316 | |
| 317 | return max((tp->snd_cwnd * beta) / BICTCP_BETA_SCALE, 2U); |
| 318 | } |
| 319 | |
| 320 | static u32 bictcp_undo_cwnd(struct sock *sk) |
| 321 | { |
| 322 | struct bictcp *ca = inet_csk_ca(sk); |
| 323 | |
| 324 | return max(tcp_sk(sk)->snd_cwnd, ca->last_max_cwnd); |
| 325 | } |
| 326 | |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 327 | static void bictcp_state(struct sock *sk, u8 new_state) |
| 328 | { |
| 329 | if (new_state == TCP_CA_Loss) |
| 330 | bictcp_reset(inet_csk_ca(sk)); |
| 331 | } |
| 332 | |
| 333 | /* Track delayed acknowledgment ratio using sliding window |
| 334 | * ratio = (15*ratio + sample) / 16 |
| 335 | */ |
| 336 | static void bictcp_acked(struct sock *sk, u32 cnt) |
| 337 | { |
| 338 | const struct inet_connection_sock *icsk = inet_csk(sk); |
| 339 | |
| 340 | if (cnt > 0 && icsk->icsk_ca_state == TCP_CA_Open) { |
| 341 | struct bictcp *ca = inet_csk_ca(sk); |
| 342 | cnt -= ca->delayed_ack >> ACK_RATIO_SHIFT; |
| 343 | ca->delayed_ack += cnt; |
| 344 | } |
| 345 | } |
| 346 | |
| 347 | |
| 348 | static struct tcp_congestion_ops cubictcp = { |
| 349 | .init = bictcp_init, |
| 350 | .ssthresh = bictcp_recalc_ssthresh, |
| 351 | .cong_avoid = bictcp_cong_avoid, |
| 352 | .set_state = bictcp_state, |
| 353 | .undo_cwnd = bictcp_undo_cwnd, |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 354 | .pkts_acked = bictcp_acked, |
| 355 | .owner = THIS_MODULE, |
| 356 | .name = "cubic", |
| 357 | }; |
| 358 | |
| 359 | static int __init cubictcp_register(void) |
| 360 | { |
Alexey Dobriyan | 74975d4 | 2006-08-25 17:10:33 -0700 | [diff] [blame] | 361 | BUILD_BUG_ON(sizeof(struct bictcp) > ICSK_CA_PRIV_SIZE); |
Stephen Hemminger | 89b3d9a | 2005-12-21 19:32:08 -0800 | [diff] [blame] | 362 | |
| 363 | /* Precompute a bunch of the scaling factors that are used per-packet |
| 364 | * based on SRTT of 100ms |
| 365 | */ |
| 366 | |
| 367 | beta_scale = 8*(BICTCP_BETA_SCALE+beta)/ 3 / (BICTCP_BETA_SCALE - beta); |
| 368 | |
| 369 | cube_rtt_scale = (bic_scale << 3) / 10; /* 1024*c/rtt */ |
| 370 | |
| 371 | /* calculate the "K" for (wmax-cwnd) = c/rtt * K^3 |
| 372 | * so K = cubic_root( (wmax-cwnd)*rtt/c ) |
| 373 | * the unit of K is bictcp_HZ=2^10, not HZ |
| 374 | * |
| 375 | * c = bic_scale >> 10 |
| 376 | * rtt = 100ms |
| 377 | * |
| 378 | * the following code has been designed and tested for |
| 379 | * cwnd < 1 million packets |
| 380 | * RTT < 100 seconds |
| 381 | * HZ < 1,000,00 (corresponding to 10 nano-second) |
| 382 | */ |
| 383 | |
| 384 | /* 1/c * 2^2*bictcp_HZ * srtt */ |
| 385 | cube_factor = 1ull << (10+3*BICTCP_HZ); /* 2^40 */ |
| 386 | |
| 387 | /* divide by bic_scale and by constant Srtt (100ms) */ |
| 388 | do_div(cube_factor, bic_scale * 10); |
| 389 | |
Stephen Hemminger | df3271f | 2005-12-13 23:13:28 -0800 | [diff] [blame] | 390 | return tcp_register_congestion_control(&cubictcp); |
| 391 | } |
| 392 | |
| 393 | static void __exit cubictcp_unregister(void) |
| 394 | { |
| 395 | tcp_unregister_congestion_control(&cubictcp); |
| 396 | } |
| 397 | |
| 398 | module_init(cubictcp_register); |
| 399 | module_exit(cubictcp_unregister); |
| 400 | |
| 401 | MODULE_AUTHOR("Sangtae Ha, Stephen Hemminger"); |
| 402 | MODULE_LICENSE("GPL"); |
| 403 | MODULE_DESCRIPTION("CUBIC TCP"); |
| 404 | MODULE_VERSION("2.0"); |