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
......@@ -74,7 +74,7 @@ static void tcp_yeah_pkts_acked(struct sock *sk, u32 pkts_acked)
}
static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack,
u32 seq_rtt, u32 in_flight, int flag)
u32 seq_rtt, u32 in_flight, int flag)
{
struct tcp_sock *tp = tcp_sk(sk);
struct yeah *yeah = inet_csk_ca(sk);
......@@ -142,8 +142,8 @@ static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack,
*/
if (yeah->cntRTT > 2) {
u32 rtt;
u32 queue, maxqueue;
u32 rtt, queue;
u64 bw;
/* We have enough RTT samples, so, using the Vegas
* algorithm, we determine if we should increase or
......@@ -158,32 +158,36 @@ static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack,
*/
rtt = yeah->minRTT;
queue = (u32)div64_64((u64)tp->snd_cwnd * (rtt - yeah->baseRTT), rtt);
maxqueue = TCP_YEAH_ALPHA;
if (queue > maxqueue ||
rtt - yeah->baseRTT > (yeah->baseRTT / TCP_YEAH_PHY)) {
if (queue > maxqueue && tp->snd_cwnd > yeah->reno_count) {
u32 reduction = min( queue / TCP_YEAH_GAMMA ,
tp->snd_cwnd >> TCP_YEAH_EPSILON );
/* Compute excess number of packets above bandwidth
* Avoid doing full 64 bit divide.
*/
bw = tp->snd_cwnd;
bw *= rtt - yeah->baseRTT;
do_div(bw, rtt);
queue = bw;
if (queue > TCP_YEAH_ALPHA ||
rtt - yeah->baseRTT > (yeah->baseRTT / TCP_YEAH_PHY)) {
if (queue > TCP_YEAH_ALPHA
&& tp->snd_cwnd > yeah->reno_count) {
u32 reduction = min(queue / TCP_YEAH_GAMMA ,
tp->snd_cwnd >> TCP_YEAH_EPSILON);
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;
}
}
if (yeah->reno_count <= 2)
yeah->reno_count = max( tp->snd_cwnd>>1, 2U);
yeah->reno_count = max(tp->snd_cwnd>>1, 2U);
else
yeah->reno_count++;
yeah->doing_reno_now =
min_t( u32, yeah->doing_reno_now + 1 , 0xffffff);
yeah->doing_reno_now = min(yeah->doing_reno_now + 1,
0xffffffU);
} else {
yeah->fast_count++;
......
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