Re: [patch 07/11] x86/perf/uncore: Track packages not per cpu data

From: Thomas Gleixner
Date: Wed Feb 17 2016 - 16:58:04 EST


On Wed, 17 Feb 2016, Andi Kleen wrote:

> Stephane Eranian <eranian@xxxxxxxxxx> writes:
>
> >>
> > Let's assume you have a system with 48 cpus with HT on, then
> > you have 2 processor sockets, which is correct. But then you further
> > assume that topology_physical_package_id() will return 0 or 1 in this case.
> > In other words, that physical id are always assigned from 0 to N in a contiguous
> > manner.
> >
> > Do we know for sure that this is always the case for all Intel systems
> > and that no
> > weird BIOS is assigning random numbers for phys_proc_id?
>
> I don't believe that is a safe assumption.

Do you have any data to back that up or is that just "believe" ?

Thanks,

tglx