Messages in this thread | | | Date | Wed, 1 Jul 2009 00:31:38 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCHSET] percpu: generalize first chunk allocators and improve lpage NUMA support |
| |
* Christoph Lameter <cl@linux-foundation.org> 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
| |