Re: [Lse-tech] Node affine NUMA scheduler extension

Martin J. Bligh (mbligh@aracnet.com)
Wed, 28 May 2003 12:32:13 -0700


> Can you define what you mean by big vs small? I presume you mean RSS?
> There are several factors that come into play here, at least:
>
> 1. RSS (and which bits of this lie on which node)
> 2. CPU utilisation of the task
> 3. Task duration
> 4. Cache warmth
> 5. the current balance situation.
>
> Along the same lines, would it make sense to *permit* imbalances for some
> classes of tasks? It may be worth it, for example, to let three threads
> sharing a lot of data to saturate one cpu because what they lose from
> their self-competition is saved from the extremely warm cache.
>
> So you leave cpu0 at 7 tasks even though cpu1 only has 4, because the 7 are
> "related" and the 4 are "dissimilar"? The equation changes dramatically,
> perhaps, once their is an idle cpu, but if everything is busy does it make
> sense to weight the items in the runqueues in any way?

It'd make sense ... but I think it would be a bitch to implement ;-)
How do you know when it's worth it?

M.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/