On Mon, Apr 16, 2012 at 11:45:44AM +0200, Alexander Graf wrote: > While trying to trace down why some BookE systems were only able to > do as many guest vcpus as there were host cpus available, we > stumbled over this one. Is there any limitation on book3s_hv that > would limit the available vcpus to configured host vcpus? Or could > we just make this a static define like on x86? There is no limitation. I did it like that so that we would be able to have a large number of vcpus on kernels configured for large systems, while not using up large amounts of memory if the kernel is configured for a small system. The memory consumption is 8 bytes per vcore in each struct kvm if book3s_hv is configured. We can make it a fixed constant if you like, but then the question is how do you choose that constant so as to allow us to have many vcpus on large systems but still not waste too much memory on small systems. Or it could be max(N, NR_CPUS) for a suitable N (e.g. 16 or 32). Paul. -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
