Re: port-shark/57613: Abysmal network performance on shark

[=?x-unknown?q?Bj=C3=B6rn_Johannesson?= <herdware%sdf.org@localhost>]

On Mon, 11 Sep 2023, Martin Husemann wrote:

> This could depend on your switch or the negotiated link.
> Can you check ifconfig output and also error counters?
Well this is embarrassing. I took all the things you wanted and tested two 
separate network switches. The problem turns out that "mediaopt full-duplex"
fubars everything. Don't even remember that. I briefly tested this with 
netbsd-9 before going to netbsd-10 and I can remember that network was 
pretty pants on that too. Unsure of when that full-duplex was added 
though. Removing full-duplex makes the net behave normally.

FTR there was zero in the error counters even when using full-duplex.

Perhaps it would be possible to turn off the possibility to enable 
full-duplex since it's so broken? (Other stuff connected to that switch 
runs fine full-duplex.)

The other problem that nfs-root hangs going multi-user turns out 
to be that /etc/rc.d/network flushes routes after setting (or not in this 
case) NIS/YP domain. Since this shark is on another subnet than the file 
server and the gateway the machine got from dhcpd got flushed things 
break.
Setting flushroutes=NO in rc.conf fixes the problem but is that the 
intended way? After network_start_domainname() flushes the route we can 
never reach network_start_defaultroute() which comes later.

Anyway, sorry for the noise and please close this PR.

/B