Re: quite big breakthrough in the BAD network performance, which mm6 did not fix

[Redeeman <lkml@metanurb.dk>]

just entered the site again with window scaling set to 1.
i have patched my kernel with the patch from the tcp_default_win_scale
thread, should i try without?
On Wed, 2004-07-07 at 10:19 +0200, bert hubert wrote:
> On Wed, Jul 07, 2004 at 08:37:44AM +0200, Redeeman wrote:
> 
> > its 1 as default, using the tcp patch from another thread fixes so that i can connect to sites. (packages.gentoo.org etc)
> > where before that patch came, i echo'ed 0 into it, and it worked aswell,
> > however i didnt get more than 50kb/s either :|
> 
> Redeeman, from your trace to outpost.ds9a.nl:10000 I note that something in
> your path removes the wscale option, or that you have turned off window
> scaling entirely. Can you check /proc/sys/net/ipv4/tcp_window_scaling ?
> 
> 43.909623 redeeman.33083 > 213.244.168.210.10000: S 4031970603:4031970603(0) 
> 	win 5840 <mss 1322,sackOK,timestamp 23502 0>
> 43.909678 213.244.168.210.10000 > redeeman.33083: S 634167324:634167324(0) 
> 	ack 4031970604 win 5792 <mss 1460,sackOK,timestamp 2136531455 23502> (DF)
> 43.951129 redeeman.33083 > 213.244.168.210.10000: . 
> 	ack 1 win 5840 <nop,nop,timestamp 23543 2136531455>
> 
> I also note that you most probably have tcp_default_win_scale set to 0.
> 
> Can you confirm for me that with 2.6.7-mm6 (and exactly that version)
> 	- you have no TCP connectivity to packages.gentoo.org by default
yes
> 
> 	- you can access packages.gentoo.org with /proc/sys/net/ipv4/tcp_default_win_scale
> 	  at both 1 and 0
yes
> 
> 	- that speed, even with tcp_default_win_scale set to 0, is
> 	  significantly lower than with stock 2.6.7, that is, if you
> 	  download some big files, and measure that, and then reboot
> 	  immediately to 2.6.7, things get lots faster
yes
> 
> Alternatively, can you reboot to a kernel with the problem ("can't connect
> to packages.gentoo.org") and try to connect to http://outpost.ds9a.nl:10000
> and tcpdump that and send me the dump (if it does in fact not work).
> 
> Regards,
> 
> bert
>