Subject: Re: [PATCH] sch_htb: ix the deficit overflows

From: Jarek Poplawski <[email-masked]>
Date: Wed, 2 Dec 2009 10:32:04 +0000

On Wed, Dec 02, 2009 at 01:20:17AM -0800, David Miller wrote:
> From: Jarek Poplawski <[email-masked]>
> Date: Mon, 30 Nov 2009 11:10:20 +0000
> 
> > On Mon, Nov 30, 2009 at 12:26:33PM +0800, Changli Gao wrote:
> >> And
> >> if we use IMQ to shape traffic, the skb will be defragmented by
> >> conntrack, and its size will be larger than MTU.
> > 
> > IMQ is a very nice thing, but it's considered broken as well, so it
> > can't be the reason for changing HTB.
> 
> If you don't like IMQ, fine.  Simply consider TSO and GSO as another
> set of mechanisms that can introduce this condition.
> 
> Because we toss large SKBs all over the strack quite freely,
> protections like those suggested by Changli make perfect sense.
> 
> We really don't have an MTU for packets within our stack any more.
> The code, by default, need to be able to handle anything.

Alas, an MTU is still a crucial parameter for some schedulers. Anyway,
I hope Changli wasn't mislead to treat my private opinions in this or
any other thread as decisive. Otherwise, I'm sorry.

Jarek P.