Re: [PATCHSET] percpu: generalize first chunk allocators andimprove lpage NUMA support

[Ingo Molnar]

* Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx> wrote:

> On Tue, 30 Jun 2009, Ingo Molnar wrote:
> 
> > But what if not? What if the kernel can run on up to 4096 CPUs 
> > and runs on a big box. Why should a virtual machine have the 
> > illogical choice between either wasting a lot of RAM 
> > preallocating stuff, or limiting its own extendability.
> 
> The kernel may be able to run on 4096 but the machines config 
> information that is available via ACPI knows how many processors 
> the machine we are booting on is able to add.

I think we might be talking past each other.

The usecase i'm talking about is to boot a generic, 
many-CPUs-capable kernel in a guest image.

How would you allow that guest to stay on 2 virtual CPUs but still 
be able to hot-plug many other CPUs if the guest context rises above 
its original CPU utilization?

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