On Mon, 2005-02-21 at 10:34, Thomas Graf wrote:
> * jamal <1108996313.1090.178.camel@xxxxxxxxxxxxxxxx> 2005-02-21 09:31
> >
> > I have done the experiments and even posted the patches on netdev last
> > year to batch on enqueue.
>
> Right, I slightly remember. I have a head like a sieve. Can you
> remmeber the subject of the post? I can't find it in the archive.
>
I cant remember - patches are on another machine; the last time i posted
was with some folks from .it who were trying to improve routing
perfomance.
> > Infact performance goes down when you batch in some cases depending on
> > the hardware used. My investigation shows that if you have a fast CPU
> > and a fast bus, theres always only one packet in flight within the
> > stack. Batching by definition requires more than one packet.
>
> Make sense but we probably have multiple packets in the stack if qdiscs are
> involved.
No - thats the problem. Theres always no more than one packet i.e only
packet in flight except in the case of some hardware - which i pointed
out as problematic in my SUCON presentation.
Maybe i should write a paper about this - i spent christmas collecting a
lot of data using relayfs;
cheers,
jamal
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