1/*-
2 * Copyright (c) 2009-2010
3 * Swinburne University of Technology, Melbourne, Australia
4 * Copyright (c) 2010 Lawrence Stewart <lstewart@freebsd.org>
5 * Copyright (c) 2010-2011 The FreeBSD Foundation
6 * All rights reserved.
7 *
8 * This software was developed at the Centre for Advanced Internet
9 * Architectures, Swinburne University of Technology, by David Hayes and
10 * Lawrence Stewart, made possible in part by a grant from the Cisco University
11 * Research Program Fund at Community Foundation Silicon Valley.
12 *
13 * Portions of this software were developed at the Centre for Advanced Internet
14 * Architectures, Swinburne University of Technology, Melbourne, Australia by
15 * David Hayes under sponsorship from the FreeBSD Foundation.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
19 * are met:
20 * 1. Redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer.
22 * 2. Redistributions in binary form must reproduce the above copyright
23 * notice, this list of conditions and the following disclaimer in the
24 * documentation and/or other materials provided with the distribution.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 */
38
39/*
40 * An implementation of the Vegas congestion control algorithm for FreeBSD,
41 * based on L. S. Brakmo and L. L. Peterson, "TCP Vegas: end to end congestion
42 * avoidance on a global internet", IEEE J. Sel. Areas Commun., vol. 13, no. 8,
43 * pp. 1465-1480, Oct. 1995. The original Vegas duplicate ack policy has not
44 * been implemented, since clock ticks are not as coarse as they were (i.e.
45 * 500ms) when Vegas was designed. Also, packets are timed once per RTT as in
46 * the original paper.
47 *
48 * Originally released as part of the NewTCP research project at Swinburne
49 * University of Technology's Centre for Advanced Internet Architectures,
50 * Melbourne, Australia, which was made possible in part by a grant from the
51 * Cisco University Research Program Fund at Community Foundation Silicon
52 * Valley. More details are available at:
53 * http://caia.swin.edu.au/urp/newtcp/
54 */
55
56#include <sys/cdefs.h>
| 1/*-
2 * Copyright (c) 2009-2010
3 * Swinburne University of Technology, Melbourne, Australia
4 * Copyright (c) 2010 Lawrence Stewart <lstewart@freebsd.org>
5 * Copyright (c) 2010-2011 The FreeBSD Foundation
6 * All rights reserved.
7 *
8 * This software was developed at the Centre for Advanced Internet
9 * Architectures, Swinburne University of Technology, by David Hayes and
10 * Lawrence Stewart, made possible in part by a grant from the Cisco University
11 * Research Program Fund at Community Foundation Silicon Valley.
12 *
13 * Portions of this software were developed at the Centre for Advanced Internet
14 * Architectures, Swinburne University of Technology, Melbourne, Australia by
15 * David Hayes under sponsorship from the FreeBSD Foundation.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
19 * are met:
20 * 1. Redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer.
22 * 2. Redistributions in binary form must reproduce the above copyright
23 * notice, this list of conditions and the following disclaimer in the
24 * documentation and/or other materials provided with the distribution.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 */
38
39/*
40 * An implementation of the Vegas congestion control algorithm for FreeBSD,
41 * based on L. S. Brakmo and L. L. Peterson, "TCP Vegas: end to end congestion
42 * avoidance on a global internet", IEEE J. Sel. Areas Commun., vol. 13, no. 8,
43 * pp. 1465-1480, Oct. 1995. The original Vegas duplicate ack policy has not
44 * been implemented, since clock ticks are not as coarse as they were (i.e.
45 * 500ms) when Vegas was designed. Also, packets are timed once per RTT as in
46 * the original paper.
47 *
48 * Originally released as part of the NewTCP research project at Swinburne
49 * University of Technology's Centre for Advanced Internet Architectures,
50 * Melbourne, Australia, which was made possible in part by a grant from the
51 * Cisco University Research Program Fund at Community Foundation Silicon
52 * Valley. More details are available at:
53 * http://caia.swin.edu.au/urp/newtcp/
54 */
55
56#include <sys/cdefs.h>
|
77#include <netinet/cc/cc_module.h>
78
79#include <netinet/khelp/h_ertt.h>
80
81#define CAST_PTR_INT(X) (*((int*)(X)))
82
83/*
84 * Private signal type for rate based congestion signal.
85 * See <netinet/cc.h> for appropriate bit-range to use for private signals.
86 */
87#define CC_VEGAS_RATE 0x01000000
88
89static void vegas_ack_received(struct cc_var *ccv, uint16_t ack_type);
90static void vegas_cb_destroy(struct cc_var *ccv);
91static int vegas_cb_init(struct cc_var *ccv);
92static void vegas_cong_signal(struct cc_var *ccv, uint32_t signal_type);
93static void vegas_conn_init(struct cc_var *ccv);
94static int vegas_mod_init(void);
95
96struct vegas {
97 int slow_start_toggle;
98};
99
100static int32_t ertt_id;
101
102static VNET_DEFINE(uint32_t, vegas_alpha) = 1;
103static VNET_DEFINE(uint32_t, vegas_beta) = 3;
104#define V_vegas_alpha VNET(vegas_alpha)
105#define V_vegas_beta VNET(vegas_beta)
106
107static MALLOC_DEFINE(M_VEGAS, "vegas data",
108 "Per connection data required for the Vegas congestion control algorithm");
109
110struct cc_algo vegas_cc_algo = {
111 .name = "vegas",
112 .ack_received = vegas_ack_received,
113 .cb_destroy = vegas_cb_destroy,
114 .cb_init = vegas_cb_init,
115 .cong_signal = vegas_cong_signal,
116 .conn_init = vegas_conn_init,
117 .mod_init = vegas_mod_init
118};
119
120/*
121 * The vegas window adjustment is done once every RTT, as indicated by the
122 * ERTT_NEW_MEASUREMENT flag. This flag is reset once the new measurment data
123 * has been used.
124 */
125static void
126vegas_ack_received(struct cc_var *ccv, uint16_t ack_type)
127{
128 struct ertt *e_t;
129 struct vegas *vegas_data;
130 long actual_tx_rate, expected_tx_rate, ndiff;
131
132 e_t = khelp_get_osd(CCV(ccv, osd), ertt_id);
133 vegas_data = ccv->cc_data;
134
135 if (e_t->flags & ERTT_NEW_MEASUREMENT) { /* Once per RTT. */
136 if (e_t->minrtt && e_t->markedpkt_rtt) {
137 expected_tx_rate = e_t->marked_snd_cwnd / e_t->minrtt;
138 actual_tx_rate = e_t->bytes_tx_in_marked_rtt /
139 e_t->markedpkt_rtt;
140 ndiff = (expected_tx_rate - actual_tx_rate) *
141 e_t->minrtt / CCV(ccv, t_maxseg);
142
143 if (ndiff < V_vegas_alpha) {
144 if (CCV(ccv, snd_cwnd) <=
145 CCV(ccv, snd_ssthresh)) {
146 vegas_data->slow_start_toggle =
147 vegas_data->slow_start_toggle ?
148 0 : 1;
149 } else {
150 vegas_data->slow_start_toggle = 0;
151 CCV(ccv, snd_cwnd) =
152 min(CCV(ccv, snd_cwnd) +
153 CCV(ccv, t_maxseg),
154 TCP_MAXWIN << CCV(ccv, snd_scale));
155 }
156 } else if (ndiff > V_vegas_beta) {
157 /* Rate-based congestion. */
158 vegas_cong_signal(ccv, CC_VEGAS_RATE);
159 vegas_data->slow_start_toggle = 0;
160 }
161 }
162 e_t->flags &= ~ERTT_NEW_MEASUREMENT;
163 }
164
165 if (vegas_data->slow_start_toggle)
166 newreno_cc_algo.ack_received(ccv, ack_type);
167}
168
169static void
170vegas_cb_destroy(struct cc_var *ccv)
171{
172
173 if (ccv->cc_data != NULL)
174 free(ccv->cc_data, M_VEGAS);
175}
176
177static int
178vegas_cb_init(struct cc_var *ccv)
179{
180 struct vegas *vegas_data;
181
182 vegas_data = malloc(sizeof(struct vegas), M_VEGAS, M_NOWAIT);
183
184 if (vegas_data == NULL)
185 return (ENOMEM);
186
187 vegas_data->slow_start_toggle = 1;
188 ccv->cc_data = vegas_data;
189
190 return (0);
191}
192
193/*
194 * If congestion has been triggered triggered by the Vegas measured rates, it is
195 * handled here, otherwise it falls back to newreno's congestion handling.
196 */
197static void
198vegas_cong_signal(struct cc_var *ccv, uint32_t signal_type)
199{
200 struct vegas *vegas_data;
201 int presignalrecov;
202
203 vegas_data = ccv->cc_data;
204
205 if (IN_RECOVERY(CCV(ccv, t_flags)))
206 presignalrecov = 1;
207 else
208 presignalrecov = 0;
209
210 switch(signal_type) {
211 case CC_VEGAS_RATE:
212 if (!IN_RECOVERY(CCV(ccv, t_flags))) {
213 CCV(ccv, snd_cwnd) = max(2 * CCV(ccv, t_maxseg),
214 CCV(ccv, snd_cwnd) - CCV(ccv, t_maxseg));
215 if (CCV(ccv, snd_cwnd) < CCV(ccv, snd_ssthresh))
216 /* Exit slow start. */
217 CCV(ccv, snd_ssthresh) = CCV(ccv, snd_cwnd);
218 }
219 break;
220
221 default:
222 newreno_cc_algo.cong_signal(ccv, signal_type);
223 }
224
225 if (IN_RECOVERY(CCV(ccv, t_flags)) && !presignalrecov)
226 vegas_data->slow_start_toggle =
227 (CCV(ccv, snd_cwnd) < CCV(ccv, snd_ssthresh)) ? 1 : 0;
228}
229
230static void
231vegas_conn_init(struct cc_var *ccv)
232{
233 struct vegas *vegas_data;
234
235 vegas_data = ccv->cc_data;
236 vegas_data->slow_start_toggle = 1;
237}
238
239static int
240vegas_mod_init(void)
241{
242
243 ertt_id = khelp_get_id("ertt");
244 if (ertt_id <= 0) {
245 printf("%s: h_ertt module not found\n", __func__);
246 return (ENOENT);
247 }
248
249 vegas_cc_algo.after_idle = newreno_cc_algo.after_idle;
250 vegas_cc_algo.post_recovery = newreno_cc_algo.post_recovery;
251
252 return (0);
253}
254
255static int
256vegas_alpha_handler(SYSCTL_HANDLER_ARGS)
257{
258 int error;
259 uint32_t new;
260
261 new = V_vegas_alpha;
262 error = sysctl_handle_int(oidp, &new, 0, req);
263 if (error == 0 && req->newptr != NULL) {
264 if (CAST_PTR_INT(req->newptr) < 1 ||
265 CAST_PTR_INT(req->newptr) > V_vegas_beta)
266 error = EINVAL;
267 else
268 V_vegas_alpha = new;
269 }
270
271 return (error);
272}
273
274static int
275vegas_beta_handler(SYSCTL_HANDLER_ARGS)
276{
277 int error;
278 uint32_t new;
279
280 new = V_vegas_beta;
281 error = sysctl_handle_int(oidp, &new, 0, req);
282 if (error == 0 && req->newptr != NULL) {
283 if (CAST_PTR_INT(req->newptr) < 1 ||
284 CAST_PTR_INT(req->newptr) < V_vegas_alpha)
285 error = EINVAL;
286 else
287 V_vegas_beta = new;
288 }
289
290 return (error);
291}
292
293SYSCTL_DECL(_net_inet_tcp_cc_vegas);
294SYSCTL_NODE(_net_inet_tcp_cc, OID_AUTO, vegas, CTLFLAG_RW, NULL,
295 "Vegas related settings");
296
297SYSCTL_PROC(_net_inet_tcp_cc_vegas, OID_AUTO, alpha,
298 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW,
299 &VNET_NAME(vegas_alpha), 1, &vegas_alpha_handler, "IU",
300 "vegas alpha, specified as number of \"buffers\" (0 < alpha < beta)");
301
302SYSCTL_PROC(_net_inet_tcp_cc_vegas, OID_AUTO, beta,
303 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW,
304 &VNET_NAME(vegas_beta), 3, &vegas_beta_handler, "IU",
305 "vegas beta, specified as number of \"buffers\" (0 < alpha < beta)");
306
307DECLARE_CC_MODULE(vegas, &vegas_cc_algo);
308MODULE_DEPEND(vegas, ertt, 1, 1, 1);
| 76#include <netinet/cc/cc_module.h>
77
78#include <netinet/khelp/h_ertt.h>
79
80#define CAST_PTR_INT(X) (*((int*)(X)))
81
82/*
83 * Private signal type for rate based congestion signal.
84 * See <netinet/cc.h> for appropriate bit-range to use for private signals.
85 */
86#define CC_VEGAS_RATE 0x01000000
87
88static void vegas_ack_received(struct cc_var *ccv, uint16_t ack_type);
89static void vegas_cb_destroy(struct cc_var *ccv);
90static int vegas_cb_init(struct cc_var *ccv);
91static void vegas_cong_signal(struct cc_var *ccv, uint32_t signal_type);
92static void vegas_conn_init(struct cc_var *ccv);
93static int vegas_mod_init(void);
94
95struct vegas {
96 int slow_start_toggle;
97};
98
99static int32_t ertt_id;
100
101static VNET_DEFINE(uint32_t, vegas_alpha) = 1;
102static VNET_DEFINE(uint32_t, vegas_beta) = 3;
103#define V_vegas_alpha VNET(vegas_alpha)
104#define V_vegas_beta VNET(vegas_beta)
105
106static MALLOC_DEFINE(M_VEGAS, "vegas data",
107 "Per connection data required for the Vegas congestion control algorithm");
108
109struct cc_algo vegas_cc_algo = {
110 .name = "vegas",
111 .ack_received = vegas_ack_received,
112 .cb_destroy = vegas_cb_destroy,
113 .cb_init = vegas_cb_init,
114 .cong_signal = vegas_cong_signal,
115 .conn_init = vegas_conn_init,
116 .mod_init = vegas_mod_init
117};
118
119/*
120 * The vegas window adjustment is done once every RTT, as indicated by the
121 * ERTT_NEW_MEASUREMENT flag. This flag is reset once the new measurment data
122 * has been used.
123 */
124static void
125vegas_ack_received(struct cc_var *ccv, uint16_t ack_type)
126{
127 struct ertt *e_t;
128 struct vegas *vegas_data;
129 long actual_tx_rate, expected_tx_rate, ndiff;
130
131 e_t = khelp_get_osd(CCV(ccv, osd), ertt_id);
132 vegas_data = ccv->cc_data;
133
134 if (e_t->flags & ERTT_NEW_MEASUREMENT) { /* Once per RTT. */
135 if (e_t->minrtt && e_t->markedpkt_rtt) {
136 expected_tx_rate = e_t->marked_snd_cwnd / e_t->minrtt;
137 actual_tx_rate = e_t->bytes_tx_in_marked_rtt /
138 e_t->markedpkt_rtt;
139 ndiff = (expected_tx_rate - actual_tx_rate) *
140 e_t->minrtt / CCV(ccv, t_maxseg);
141
142 if (ndiff < V_vegas_alpha) {
143 if (CCV(ccv, snd_cwnd) <=
144 CCV(ccv, snd_ssthresh)) {
145 vegas_data->slow_start_toggle =
146 vegas_data->slow_start_toggle ?
147 0 : 1;
148 } else {
149 vegas_data->slow_start_toggle = 0;
150 CCV(ccv, snd_cwnd) =
151 min(CCV(ccv, snd_cwnd) +
152 CCV(ccv, t_maxseg),
153 TCP_MAXWIN << CCV(ccv, snd_scale));
154 }
155 } else if (ndiff > V_vegas_beta) {
156 /* Rate-based congestion. */
157 vegas_cong_signal(ccv, CC_VEGAS_RATE);
158 vegas_data->slow_start_toggle = 0;
159 }
160 }
161 e_t->flags &= ~ERTT_NEW_MEASUREMENT;
162 }
163
164 if (vegas_data->slow_start_toggle)
165 newreno_cc_algo.ack_received(ccv, ack_type);
166}
167
168static void
169vegas_cb_destroy(struct cc_var *ccv)
170{
171
172 if (ccv->cc_data != NULL)
173 free(ccv->cc_data, M_VEGAS);
174}
175
176static int
177vegas_cb_init(struct cc_var *ccv)
178{
179 struct vegas *vegas_data;
180
181 vegas_data = malloc(sizeof(struct vegas), M_VEGAS, M_NOWAIT);
182
183 if (vegas_data == NULL)
184 return (ENOMEM);
185
186 vegas_data->slow_start_toggle = 1;
187 ccv->cc_data = vegas_data;
188
189 return (0);
190}
191
192/*
193 * If congestion has been triggered triggered by the Vegas measured rates, it is
194 * handled here, otherwise it falls back to newreno's congestion handling.
195 */
196static void
197vegas_cong_signal(struct cc_var *ccv, uint32_t signal_type)
198{
199 struct vegas *vegas_data;
200 int presignalrecov;
201
202 vegas_data = ccv->cc_data;
203
204 if (IN_RECOVERY(CCV(ccv, t_flags)))
205 presignalrecov = 1;
206 else
207 presignalrecov = 0;
208
209 switch(signal_type) {
210 case CC_VEGAS_RATE:
211 if (!IN_RECOVERY(CCV(ccv, t_flags))) {
212 CCV(ccv, snd_cwnd) = max(2 * CCV(ccv, t_maxseg),
213 CCV(ccv, snd_cwnd) - CCV(ccv, t_maxseg));
214 if (CCV(ccv, snd_cwnd) < CCV(ccv, snd_ssthresh))
215 /* Exit slow start. */
216 CCV(ccv, snd_ssthresh) = CCV(ccv, snd_cwnd);
217 }
218 break;
219
220 default:
221 newreno_cc_algo.cong_signal(ccv, signal_type);
222 }
223
224 if (IN_RECOVERY(CCV(ccv, t_flags)) && !presignalrecov)
225 vegas_data->slow_start_toggle =
226 (CCV(ccv, snd_cwnd) < CCV(ccv, snd_ssthresh)) ? 1 : 0;
227}
228
229static void
230vegas_conn_init(struct cc_var *ccv)
231{
232 struct vegas *vegas_data;
233
234 vegas_data = ccv->cc_data;
235 vegas_data->slow_start_toggle = 1;
236}
237
238static int
239vegas_mod_init(void)
240{
241
242 ertt_id = khelp_get_id("ertt");
243 if (ertt_id <= 0) {
244 printf("%s: h_ertt module not found\n", __func__);
245 return (ENOENT);
246 }
247
248 vegas_cc_algo.after_idle = newreno_cc_algo.after_idle;
249 vegas_cc_algo.post_recovery = newreno_cc_algo.post_recovery;
250
251 return (0);
252}
253
254static int
255vegas_alpha_handler(SYSCTL_HANDLER_ARGS)
256{
257 int error;
258 uint32_t new;
259
260 new = V_vegas_alpha;
261 error = sysctl_handle_int(oidp, &new, 0, req);
262 if (error == 0 && req->newptr != NULL) {
263 if (CAST_PTR_INT(req->newptr) < 1 ||
264 CAST_PTR_INT(req->newptr) > V_vegas_beta)
265 error = EINVAL;
266 else
267 V_vegas_alpha = new;
268 }
269
270 return (error);
271}
272
273static int
274vegas_beta_handler(SYSCTL_HANDLER_ARGS)
275{
276 int error;
277 uint32_t new;
278
279 new = V_vegas_beta;
280 error = sysctl_handle_int(oidp, &new, 0, req);
281 if (error == 0 && req->newptr != NULL) {
282 if (CAST_PTR_INT(req->newptr) < 1 ||
283 CAST_PTR_INT(req->newptr) < V_vegas_alpha)
284 error = EINVAL;
285 else
286 V_vegas_beta = new;
287 }
288
289 return (error);
290}
291
292SYSCTL_DECL(_net_inet_tcp_cc_vegas);
293SYSCTL_NODE(_net_inet_tcp_cc, OID_AUTO, vegas, CTLFLAG_RW, NULL,
294 "Vegas related settings");
295
296SYSCTL_PROC(_net_inet_tcp_cc_vegas, OID_AUTO, alpha,
297 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW,
298 &VNET_NAME(vegas_alpha), 1, &vegas_alpha_handler, "IU",
299 "vegas alpha, specified as number of \"buffers\" (0 < alpha < beta)");
300
301SYSCTL_PROC(_net_inet_tcp_cc_vegas, OID_AUTO, beta,
302 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW,
303 &VNET_NAME(vegas_beta), 3, &vegas_beta_handler, "IU",
304 "vegas beta, specified as number of \"buffers\" (0 < alpha < beta)");
305
306DECLARE_CC_MODULE(vegas, &vegas_cc_algo);
307MODULE_DEPEND(vegas, ertt, 1, 1, 1);
|