diff options
author | Xiaoliang (David) Wei <davidwei79@gmail.com> | 2006-07-11 13:03:28 -0700 |
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committer | David S. Miller <davem@sunset.davemloft.net> | 2006-07-12 13:58:50 -0700 |
commit | 6150c22e2ac3f7dbe73e7ae7817785070d0cff1f (patch) | |
tree | 2506ea47e5ae101ab6f0df694480b1df46267b18 /net/ipv6 | |
parent | 781b456a980ec987a4be248f236c59658f651240 (diff) |
[TCP] tcp_highspeed: Fix AI updates.
I think there is still a problem with the AIMD parameter update in
HighSpeed TCP code.
Line 125~138 of the code (net/ipv4/tcp_highspeed.c):
/* Update AIMD parameters */
if (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd) {
while (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd &&
ca->ai < HSTCP_AIMD_MAX - 1)
ca->ai++;
} else if (tp->snd_cwnd < hstcp_aimd_vals[ca->ai].cwnd) {
while (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd &&
ca->ai > 0)
ca->ai--;
In fact, the second part (decreasing ca->ai) never decreases since the
while loop's inequality is in the reverse direction. This leads to
unfairness with multiple flows (once a flow happens to enjoy a higher
ca->ai, it keeps enjoying that even its cwnd decreases)
Here is a tentative fix (I also added a comment, trying to keep the
change clear):
Acked-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6')
0 files changed, 0 insertions, 0 deletions