Subject: Re: [PATCH 2/3][NET_BATCH] net core use batching

From: Jeff Garzik <[email-masked]>
Date: Tue, 09 Oct 2007 15:04:23 -0400

Waskiewicz Jr, Peter P wrote:
>> IMO the net driver really should provide a hint as to what it wants.
>>
>> 8139cp and tg3 would probably prefer multiple TX queue 
>> behavior to match silicon behavior -- strict prio.
> 
> If I understand what you just said, I disagree.  If your hardware is
> running strict prio, you don't want to enforce strict prio in the qdisc
> layer; performing two layers of QoS is excessive, and may lead to
> results you don't want.  The reason I added the DRR qdisc is for the Si
> that has its own queueing strategy that is not RR.  For Si that
> implements RR (like e1000), you can either use the DRR qdisc, or if you
> want to prioritize your flows, use PRIO.

A misunderstanding, I think.

To my brain, DaveM's item #2 seemed to assume/require the NIC hardware 
to balance fairly across hw TX rings, which seemed to preclude the 
8139cp/tg3 style of strict-prio hardware.  That's what I was responding to.

As long as there is some modular way to fit 8139cp/tg3 style multi-TX 
into our universe, I'm happy :)

	Jeff