Eliminate need for full 6/4/64 divide to compute queue.
Variable maxqueue was really a constant.
Fix indentation.
Signed-off-by: Stephen Hemminger <[EMAIL PROTECTED]>
---
net/ipv4/tcp_yeah.c | 42 +++++++++++++++++++++++-------------------
1 file changed, 23 insertions(+), 19 deletions(-)
--- net-2.6.22.orig/net/ipv4/tcp_yeah.c 2007-03-06 11:46:34.000000000 -0800
+++ net-2.6.22/net/ipv4/tcp_yeah.c 2007-03-06 11:54:54.000000000 -0800
@@ -74,7 +74,7 @@
}
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 @@
*/
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 @@
*/
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++;
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
