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Commit 43e68392 authored by Stephen Hemminger's avatar Stephen Hemminger Committed by David S. Miller
Browse files

[TCP] TCP Yeah: cleanup 



Eliminate need for full 6/4/64 divide to compute queue.
Variable maxqueue was really a constant.
Fix indentation.

Signed-off-by: default avatarStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c5f5877c

net/ipv4/tcp_yeah.c

+23 −19
Original line number Original line Diff line number Diff line
@@ -142,8 +142,8 @@ static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, 
		 */

		 */





		if (yeah->cntRTT > 2) {

		if (yeah->cntRTT > 2) {

			u32 rtt;

			u32 rtt, queue;

			u32 queue, maxqueue;

			u64 bw;





			/* We have enough RTT samples, so, using the Vegas

			/* We have enough RTT samples, so, using the Vegas

			 * algorithm, we determine if we should increase or

			 * algorithm, we determine if we should increase or
@@ -158,20 +158,25 @@ static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, 
			 */

			 */

			rtt = yeah->minRTT;

			rtt = yeah->minRTT;





			queue = (u32)div64_64((u64)tp->snd_cwnd * (rtt - yeah->baseRTT), rtt);

			/* Compute excess number of packets above bandwidth



			 * Avoid doing full 64 bit divide.

			maxqueue = TCP_YEAH_ALPHA;

			 */

			bw = tp->snd_cwnd;

			bw *= rtt - yeah->baseRTT;

			do_div(bw, rtt);

			queue = bw;





			if (queue > maxqueue ||

			if (queue > TCP_YEAH_ALPHA ||

			    rtt - yeah->baseRTT > (yeah->baseRTT / TCP_YEAH_PHY)) {

			    rtt - yeah->baseRTT > (yeah->baseRTT / TCP_YEAH_PHY)) {



				if (queue > TCP_YEAH_ALPHA

				if (queue > maxqueue && tp->snd_cwnd > yeah->reno_count) {

				    && tp->snd_cwnd > yeah->reno_count) {

					u32 reduction = min(queue / TCP_YEAH_GAMMA ,

					u32 reduction = min(queue / TCP_YEAH_GAMMA ,

							    tp->snd_cwnd >> TCP_YEAH_EPSILON);

							    tp->snd_cwnd >> TCP_YEAH_EPSILON);





					tp->snd_cwnd -= reduction;

					tp->snd_cwnd -= reduction;





					tp->snd_cwnd = max( tp->snd_cwnd, yeah->reno_count);

					tp->snd_cwnd = max(tp->snd_cwnd,

							   yeah->reno_count);





					tp->snd_ssthresh = tp->snd_cwnd;

					tp->snd_ssthresh = tp->snd_cwnd;

				}

				}
@@ -181,9 +186,8 @@ static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, 
				else

				else

					yeah->reno_count++;

					yeah->reno_count++;





				yeah->doing_reno_now =

				yeah->doing_reno_now = min(yeah->doing_reno_now + 1,

					           min_t( u32, yeah->doing_reno_now + 1 , 0xffffff);

							   0xffffffU);



			} else {

			} else {

				yeah->fast_count++;

				yeah->fast_count++;