net/ipv4/tcp_cdg.c

142 	struct cdg *ca = inet_csk_ca(sk);
145 	ca->delay_min = min_not_zero(ca->delay_min, ca->rtt.min);
146 	if (ca->delay_min == 0)
152 		if (ca->last_ack == 0 || !tcp_is_cwnd_limited(sk)) {
153 			ca->last_ack = now_us;
154 			ca->round_start = now_us;
155 		} else if (before(now_us, ca->last_ack + 3000)) {
156 			u32 base_owd = max(ca->delay_min / 2U, 125U);
158 			ca->last_ack = now_us;
159 			if (after(now_us, ca->round_start + base_owd)) {
172 		if (ca->sample_cnt < 8) {
173 			ca->sample_cnt++;
175 			s32 thresh = max(ca->delay_min + ca->delay_min / 8U,
178 			if (ca->rtt.min > thresh) {
190 static s32 tcp_cdg_grad(struct cdg *ca)
192 	s32 gmin = ca->rtt.min - ca->rtt_prev.min;
193 	s32 gmax = ca->rtt.max - ca->rtt_prev.max;
196 	if (ca->gradients) {
197 		ca->gsum.min += gmin - ca->gradients[ca->tail].min;
198 		ca->gsum.max += gmax - ca->gradients[ca->tail].max;
199 		ca->gradients[ca->tail].min = gmin;
200 		ca->gradients[ca->tail].max = gmax;
201 		ca->tail = (ca->tail + 1) & (window - 1);
202 		gmin = ca->gsum.min;
203 		gmax = ca->gsum.max;
215 	if (!ca->gfilled) {
216 		if (!ca->gradients && window > 1)
218 		else if (ca->tail == 0)
219 			ca->gfilled = true;
221 			grad = (grad * window) / (int)ca->tail;
226 		ca->backoff_cnt = 0;
234 			ca->state = CDG_FULL;
236 			ca->state = CDG_NONFULL;
243 	struct cdg *ca = inet_csk_ca(sk);
250 		ca->backoff_cnt++;
251 		if (ca->backoff_cnt > use_ineff)
255 	ca->shadow_wnd = max(ca->shadow_wnd, tcp_snd_cwnd(tp));
256 	ca->state = CDG_BACKOFF;
264 	struct cdg *ca = inet_csk_ca(sk);
272 	if (after(ack, ca->rtt_seq) && ca->rtt.v64) {
275 		if (ca->rtt_prev.v64)
276 			grad = tcp_cdg_grad(ca);
277 		ca->rtt_seq = tp->snd_nxt;
278 		ca->rtt_prev = ca->rtt;
279 		ca->rtt.v64 = 0;
280 		ca->last_ack = 0;
281 		ca->sample_cnt = 0;
288 		ca->shadow_wnd = min(ca->shadow_wnd, tcp_snd_cwnd(tp));
296 	ca->shadow_wnd = max(ca->shadow_wnd, ca->shadow_wnd + incr);
301 	struct cdg *ca = inet_csk_ca(sk);
312 		if (sample->pkts_acked == 1 && ca->delack) {
316 			ca->rtt.min = min(ca->rtt.min, sample->rtt_us);
317 			ca->delack--;
319 		} else if (sample->pkts_acked > 1 && ca->delack < 5) {
320 			ca->delack++;
324 	ca->rtt.min = min_not_zero(ca->rtt.min, sample->rtt_us);
325 	ca->rtt.max = max(ca->rtt.max, sample->rtt_us);
330 	struct cdg *ca = inet_csk_ca(sk);
333 	if (ca->state == CDG_BACKOFF)
336 	if (ca->state == CDG_NONFULL && use_tolerance)
339 	ca->shadow_wnd = min(ca->shadow_wnd >> 1, tcp_snd_cwnd(tp));
341 		return max3(2U, ca->shadow_wnd, tcp_snd_cwnd(tp) >> 1);
347 	struct cdg *ca = inet_csk_ca(sk);
353 		gradients = ca->gradients;
356 		memset(ca, 0, sizeof(*ca));
358 		ca->gradients = gradients;
359 		ca->rtt_seq = tp->snd_nxt;
360 		ca->shadow_wnd = tcp_snd_cwnd(tp);
363 		ca->state = CDG_UNKNOWN;
364 		ca->rtt_seq = tp->snd_nxt;
365 		ca->rtt_prev = ca->rtt;
366 		ca->rtt.v64 = 0;
375 	struct cdg *ca = inet_csk_ca(sk);
378 	ca->gradients = NULL;
381 		ca->gradients = kcalloc(window, sizeof(ca->gradients[0]),
383 	ca->rtt_seq = tp->snd_nxt;
384 	ca->shadow_wnd = tcp_snd_cwnd(tp);
389 	struct cdg *ca = inet_csk_ca(sk);
391 	kfree(ca->gradients);
392 	ca->gradients = NULL;