On Mon, 2007-11-06 at 14:39 +0200, Patrick McHardy wrote:

jamal wrote:

quoted

On Mon, 2007-11-06 at 13:58 +0200, Patrick McHardy wrote:

quoted

Sure. Packets stashed on the any DMA ring are considered "gone to the
wire". That is a very valid assumption to make.

I disagree, its obviously not true 

Patrick, you are making too strong a statement. Take a step back:
When you put a packet on the DMA ring, are you ever going to take it
away at some point before it goes to the wire? 

and leads to the behaviour I
described. If it were true there would be no reason to use multiple
HW TX queues to begin with.

In the general case, they are totaly useless.
They are  useful when theres contention/congestion. Even in a shared
media like wireless. 
And if there is contention, the qdisc scheduler will do the right thing.

cheers,
jamal