net/ipv4/tcp_htcp.c

49 static inline u32 htcp_cong_time(const struct htcp *ca)
51 	return jiffies - ca->last_cong;
54 static inline u32 htcp_ccount(const struct htcp *ca)
56 	return htcp_cong_time(ca) / ca->minRTT;
59 static inline void htcp_reset(struct htcp *ca)
61 	ca->undo_last_cong = ca->last_cong;
62 	ca->undo_maxRTT = ca->maxRTT;
63 	ca->undo_old_maxB = ca->old_maxB;
65 	ca->last_cong = jiffies;
70 	struct htcp *ca = inet_csk_ca(sk);
72 	if (ca->undo_last_cong) {
73 		ca->last_cong = ca->undo_last_cong;
74 		ca->maxRTT = ca->undo_maxRTT;
75 		ca->old_maxB = ca->undo_old_maxB;
76 		ca->undo_last_cong = 0;
85 	struct htcp *ca = inet_csk_ca(sk);
88 	if (ca->minRTT > srtt || !ca->minRTT)
89 		ca->minRTT = srtt;
93 		if (ca->maxRTT < ca->minRTT)
94 			ca->maxRTT = ca->minRTT;
95 		if (ca->maxRTT < srtt &&
96 		    srtt <= ca->maxRTT + msecs_to_jiffies(20))
97 			ca->maxRTT = srtt;
106 	struct htcp *ca = inet_csk_ca(sk);
110 		ca->pkts_acked = sample->pkts_acked;
120 		ca->packetcount = 0;
121 		ca->lasttime = now;
125 	ca->packetcount += sample->pkts_acked;
127 	if (ca->packetcount >= tcp_snd_cwnd(tp) - (ca->alpha >> 7 ? : 1) &&
128 	    now - ca->lasttime >= ca->minRTT &&
129 	    ca->minRTT > 0) {
130 		__u32 cur_Bi = ca->packetcount * HZ / (now - ca->lasttime);
132 		if (htcp_ccount(ca) <= 3) {
134 			ca->minB = ca->maxB = ca->Bi = cur_Bi;
136 			ca->Bi = (3 * ca->Bi + cur_Bi) / 4;
137 			if (ca->Bi > ca->maxB)
138 				ca->maxB = ca->Bi;
139 			if (ca->minB > ca->maxB)
140 				ca->minB = ca->maxB;
142 		ca->packetcount = 0;
143 		ca->lasttime = now;
147 static inline void htcp_beta_update(struct htcp *ca, u32 minRTT, u32 maxRTT)
150 		u32 maxB = ca->maxB;
151 		u32 old_maxB = ca->old_maxB;
153 		ca->old_maxB = ca->maxB;
155 			ca->beta = BETA_MIN;
156 			ca->modeswitch = 0;
161 	if (ca->modeswitch && minRTT > msecs_to_jiffies(10) && maxRTT) {
162 		ca->beta = (minRTT << 7) / maxRTT;
163 		if (ca->beta < BETA_MIN)
164 			ca->beta = BETA_MIN;
165 		else if (ca->beta > BETA_MAX)
166 			ca->beta = BETA_MAX;
168 		ca->beta = BETA_MIN;
169 		ca->modeswitch = 1;
173 static inline void htcp_alpha_update(struct htcp *ca)
175 	u32 minRTT = ca->minRTT;
177 	u32 diff = htcp_cong_time(ca);
194 	ca->alpha = 2 * factor * ((1 << 7) - ca->beta);
195 	if (!ca->alpha)
196 		ca->alpha = ALPHA_BASE;
210 	struct htcp *ca = inet_csk_ca(sk);
211 	u32 minRTT = ca->minRTT;
212 	u32 maxRTT = ca->maxRTT;
214 	htcp_beta_update(ca, minRTT, maxRTT);
215 	htcp_alpha_update(ca);
219 		ca->maxRTT = minRTT + ((maxRTT - minRTT) * 95) / 100;
225 	const struct htcp *ca = inet_csk_ca(sk);
228 	return max((tcp_snd_cwnd(tp) * ca->beta) >> 7, 2U);
234 	struct htcp *ca = inet_csk_ca(sk);
245 		if ((tp->snd_cwnd_cnt * ca->alpha)>>7 >= tcp_snd_cwnd(tp)) {
249 			htcp_alpha_update(ca);
251 			tp->snd_cwnd_cnt += ca->pkts_acked;
253 		ca->pkts_acked = 1;
259 	struct htcp *ca = inet_csk_ca(sk);
261 	memset(ca, 0, sizeof(struct htcp));
262 	ca->alpha = ALPHA_BASE;
263 	ca->beta = BETA_MIN;
264 	ca->pkts_acked = 1;
265 	ca->last_cong = jiffies;
273 			struct htcp *ca = inet_csk_ca(sk);
275 			if (ca->undo_last_cong) {
276 				ca->last_cong = jiffies;
277 				ca->undo_last_cong = 0;