[PATCH] Re: Oops in 2.3.99pre9-2/SMP

[Rusty Russell]

In message <Pine.LNX.4.21.0005251834390.10148-100000@tux.rsn.hk-r.se> you write
:
> I'm running 100baseTx-FD (I believe that's the right term for it) and I
> can reproduce it at will. Running isic against the router or throu it has
> no effect. But udpsic stops all current and new connections. tcpsic allows
> the current connections to function but _very_ slow.

OK, reproduced this, and after much profiling, I traced it down to
massive hash chain collision in the NAT code (well, other than a
debugging message about UDP checksums which will go away for 2.4.0).

It turns out that we don't need to traverse the chain anyway for most
cases: the patch in CVS fixes this, and it's much nicer.  Note that
with CONFIG_NETFILTER_DEBUG on, it's still a significant slowdown, but
without that it's fine under 100baseT and 10baseT floods.

See CVS for patch against 2.4.0-test1.
Rusty.
--
Hacking time.