86 /* RTT_ref (ms) used in the calculation of alpha if RTT scaling is enabled. */
94  * value of alpha, based on the function defined in the HTCP spec.
108  * The "16" value is the "1" term in the alpha function shifted up by
111  * The "160" value is the "10" multiplier in the alpha function multiplied by
120  * different tick timers, which we have to adjust for in the alpha calculation
155 	int		alpha;  member
169  * htcp_recalc_alpha() before alpha will stop increasing due to overflow.
215 		 * or a congestion event (when alpha equals 1).  in htcp_ack_received()
217 		if (htcp_data->alpha == 1 ||  in htcp_ack_received()
222 				/* Increment cwnd by alpha segments. */  in htcp_ack_received()
223 				CCV(ccv, snd_cwnd) += htcp_data->alpha *  in htcp_ack_received()
228 				 * Increment cwnd by alpha/cwnd segments to  in htcp_ack_received()
229 				 * approximate an increase of alpha segments  in htcp_ack_received()
232 				CCV(ccv, snd_cwnd) += (((htcp_data->alpha <<  in htcp_ack_received()
266 	htcp_data->alpha = HTCP_INIT_ALPHA;  in htcp_cb_init()
397 	int alpha, diff, now;  in htcp_recalc_alpha()  local
405 	 * the wrap point, our alpha calcs will be completely wrong. We cut our  in htcp_recalc_alpha()
406 	 * losses and restart alpha from scratch by setting t_last_cong = now -  in htcp_recalc_alpha()
410 	 * is growing by until alpha regains the value it held prior to taking  in htcp_recalc_alpha()
418 	/* Cap alpha if the value of diff would overflow HTCP_CALC_ALPHA(). */  in htcp_recalc_alpha()
422 		 * increase alpha according to the function defined in the spec.  in htcp_recalc_alpha()
425 			alpha = HTCP_CALC_ALPHA(diff);  in htcp_recalc_alpha()
432 				alpha = max(1, (2 * ((1 << HTCP_SHIFT) -  in htcp_recalc_alpha()
433 				    htcp_data->beta) * alpha) >> HTCP_SHIFT);  in htcp_recalc_alpha()
436 			 * RTT scaling: (RTT / RTT_ref) * alpha  in htcp_recalc_alpha()
437 			 * alpha will be the raw value from HTCP_CALC_ALPHA() if  in htcp_recalc_alpha()
442 				alpha = max(1, (min(max(HTCP_MINROWE,  in htcp_recalc_alpha()
444 				    htcp_rtt_ref), HTCP_MAXROWE) * alpha)  in htcp_recalc_alpha()
448 			alpha = 1;  in htcp_recalc_alpha()
450 		htcp_data->alpha = alpha;  in htcp_recalc_alpha()