| Message ID | Pine.LNX.4.64.0810211153300.7072@wrl-59.cs.helsinki.fi |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: "Ilpo Järvinen" <ilpo.jarvinen@helsinki.fi> Date: Tue, 21 Oct 2008 11:58:05 +0300 (EEST) > While looking for the recent "sack issue" I also read all eff_sacks > usage that was played around by some relevant commit. I found > out that there's another thing that is asking for a fix (unrelated > to the "sack issue" though). > > This feature has probably very little significance in practice. > Opposite direction timeout with bidirectional tcp comes to me as > the most likely scenario though there might be other cases as > well related to non-data segments we send (e.g., response to the > opposite direction segment). Also some ACK losses or option space > wasted for other purposes is necessary to prevent the earlier > SACK feedback getting to the sender. ... > Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Applied, thanks Ilpo. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 990a584..de54f02 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -432,7 +432,7 @@ static void tcp_options_write(__be32 *ptr, struct tcp_sock *tp, if (tp->rx_opt.dsack) { tp->rx_opt.dsack = 0; - tp->rx_opt.eff_sacks--; + tp->rx_opt.eff_sacks = tp->rx_opt.num_sacks; } } }
While looking for the recent "sack issue" I also read all eff_sacks usage that was played around by some relevant commit. I found out that there's another thing that is asking for a fix (unrelated to the "sack issue" though). This feature has probably very little significance in practice. Opposite direction timeout with bidirectional tcp comes to me as the most likely scenario though there might be other cases as well related to non-data segments we send (e.g., response to the opposite direction segment). Also some ACK losses or option space wasted for other purposes is necessary to prevent the earlier SACK feedback getting to the sender. This is not too critical fix, so you might want to delay this to net-next if you're afraid that Linus will get you because of this... I suppose we might not need eff_sacks at all but I'll leave figuring that out to net-next :-). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> --- net/ipv4/tcp_output.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)