Re: [RFC,5/7] NUMA hotplug emulator

Paul Mundt
2010-05-14T05:50:22Z

On Thu, May 13, 2010 at 08:14:57PM +0800, Shaohui Zheng wrote:
> hotplug emulator: support cpu probe/release in x86
>
> Add cpu interface probe/release under sysfs for x86. User can use this
> interface to emulate the cpu hot-add process, it is for cpu hotplug
> test purpose. Add a kernel option CONFIG_ARCH_CPU_PROBE_RELEASE for this
> feature.
>
> This interface provides a mechanism to emulate cpu hotplug with software
> methods, it becomes possible to do cpu hotplug automation and stress
> testing.
>
At a quick glance, is this really necessary? It seems like you could
easily replace most of this with a CPU notifier chain that takes care of
the node handling. See for example how ppc64 manages the CPU hotplug/numa
emulation case in arch/powerpc/mm/numa.c. arch_register_cpu() just looks
like some topology hack for ACPI, it would be nice not to perpetuate that
too much.