Re: [pcp] pcp updates: fix kernel.pernode.cpu metrics on single CPU systems

[Mark Goodwin <mgoodwin@xxxxxxxxxx>]

On 01/02/2015 11:25 AM, Mark Goodwin wrote:
> [...]
> Any thoughts on how we might test cpu hotplug/unplug? Do we need to even
> support it? I suspect that if the per-cpu and per-node indoms need to
> be dynamic then this isn't the only codxe that will need some attention ...
just following up here after a bit more investigation - this code needs a
cleanup and re-work. Firstly, the proc_stat and proc_cpuinfo per-cpu arrays
shoudl be merged (and similarly for the various per-node metrics), and
secondly, cpu hotplug/unplug is supported in qemu-kvm-0.12.1.2-2.250.el6
and later, see https://bugzilla.redhat.com/show_bug.cgi?id=562886 and
probably also in some h/w architectures.

I'll post a BZ for this work since this is a fairly intrusive change to
the most commonly fetched metrics in the linux PMDA, and making the cpu
and node indoms dynamic most likely has ramifications elsewhere..

Regard
-- Mark