Subject: Re: [PATCH 3/3] pkt_sched: restore multiqueue prio scheduler

From: Jarek Poplawski <[email-masked]>
Date: Sat, 23 Aug 2008 00:19:13 +0200

jamal wrote, On 08/22/2008 04:30 PM:
...
> There are two issues at stake:
> 1) egress Multiq support and the desire to have concurency based on
> however many cpus and hardware queues exist on the system.
> 2) scheduling of the such hardware queues being executed by the hardware
> (and not by software).
> 
> Daves goal: #1; run faster than Usain Bolt.

Looks fine.

> What we were solving at the time: #2. My view was to solve it with
> minimal changes.
> 
> #1 and #2 are orthogonal. Yes, there is religion: Dave yours is #1.
> Intels is #2; And there are a lot of people in intels camp because
> they bill their customers based on qos of resources. The wire being one
> such resource.

If we can guarentee that current, automatic steering gives always the
best performance than David seems to be right. But I doubt it, and
that's why I think such a simple, manual control could be useful.
Especially if it doesn't add much overhead.

> Therefore your statement that these schemes exist to "enforce fairness
> amongst the TX queues" needs to be qualified mon ami;-> The end parts of
> Animal Farm come to mind: Some animals have more rights than others;->

Sure, but shouldn't this other kind of fairness be applied on lower
levels?

Cheers,
Jarek P.