Re: bad TSO performance in 2.6.9-rc2-BK

[Andi Kleen <ak@xxxxxxx>]

On Tue, Sep 28, 2004 at 02:53:45PM -0700, David S. Miller wrote:
> On Tue, 28 Sep 2004 23:34:15 +0200
> Andi Kleen <ak@xxxxxxx> wrote:
> 
> > I admit I lost track of all your patches now - can you give me a big
> > diff against the latest BK so that I can check that the problem
> > is gone for me too? 
> 
> Here are all of the pending TCP bug fixes, attached in order.
> I'll be pushing these to Linus some time today.

I'm afraid I must report it's still not completely solved for me yet.
10s netperf with TSO on with your patches gives now ~10MB/s less than 
with TSO off (57 vs 67). It's better than before, but not really
fixed yet.

Looking at my tcpdumps and comparing TSO on/off I see a quite
strange effect. It only acks on every ~25th packet with TSO off
but every ~16th packet with TSO on.

Receiver is a 2.6.5 kernel, it's weird that it violates the
ack every two MSS rule.

-Andi