[openib-general] Re: TSO and IPoIB performance degradation

[Lennert Buytenhek]

On Mon, Mar 20, 2006 at 12:47:03PM +0100, Arjan van de Ven wrote:

> > > I disagree with Linux changing it's behavior.  It would be great to
> > > turn off congestion control completely over local gigabit networks,
> > > but that isn't determinable in any way, so we don't do that.
> > 
> > Interesting. Would it make sense to make it another tunable knob in
> > /proc, sysfs or sysctl then?
> 
> that's not the right level; since that is per interface. And you only
> know the actual interface waay too late (as per earlier posts).
> Per socket.. maybe
> But then again it's not impossible to have packets for one socket go out
> to multiple interfaces
> (think load balancing bonding over 2 interfaces, one IB another
> ethernet)

I read it as if he was proposing to have a sysctl knob to turn off
TCP congestion control completely (which has so many issues it's not
even funny.)