[Techtalk] Can't get to http://linuxchix.org

[Akkana Peck]

Conor Daly writes:
> Akkana said:
> > linuxchix.org, but 2.6.8.1 couldn't.  Perhaps 2.6.9 changed the
> > tcp_default_win_scale, or its handling of it, to be more tolerant?
> 
> What is the value of /proc/sys/net/ipv4/tcp_default_window_scale with the
> 2.6.9 kernels?  Is it less than 7?

That file doesn't exist on this 2.6.9 system.  But
/proc/sys/net/ipv4/tcp_window_scaling is 1, and there's
nothing controlling it in /etc/sysctl.conf.

In net/ipv4/tcp_input.c for 2.6.9 I see:

int sysctl_tcp_window_scaling = 1;

and I don't see any other obvious place where the initial value
would get changed to anything else except in sysctl_net_ipv4.c
(which seems to be the sysctl.conf reading code).

But that doesn't mean anything since I see the same code in the
2.6.8.1 source, and that kernel did exhibit the problem.

But diffing the two directories does suggest that the relevant
code has been rewritten; there are lots of changes related to
win_scale and it also looks like the relevant sysctl parameter
has been renamed (2.6.8.1 has "tcp_default_win_scale", defaulting to
7, while 2.6.9 has "tcp_tso_win_divisor", defaulting to 8).


	...Akkana