On Tue, Jul 12, 2016 at 04:55:51PM +0200, Peter Zijlstra wrote:
> On Sun, Jul 10, 2016 at 07:43:27AM -0700, Paul E. McKenney wrote:
> > On Sun, Jul 10, 2016 at 07:17:19AM +0200, Peter Zijlstra wrote:
> > >
> > >
> > > On 10 July 2016 06:26:39 CEST, "Paul E. McKenney"
> > > <paul...@linux.vnet.ibm.com> wrote:
> > > >Hello!
> > > >
> > > >So I ran a quick benchmark which showed stair-step results. I
> > > >immediately
> > > >thought "Ah, this is due to CPU 0 and 1, 2 and 3, 4 and 5, and 6 and 7
> > > >being threads in a core." Then I thought "Wait, this is an x86!"
> > > >Then I dumped out cpu*/topology/thread_siblings_list, getting the
> > > >following:
> > > >
> > > > cpu0/topology/thread_siblings_list: 0-1
> > > > cpu1/topology/thread_siblings_list: 0-1
> > > > cpu2/topology/thread_siblings_list: 2-3
> > > > cpu3/topology/thread_siblings_list: 2-3
> > > > cpu4/topology/thread_siblings_list: 4-5
> > > > cpu5/topology/thread_siblings_list: 4-5
> > > > cpu6/topology/thread_siblings_list: 6-7
> > > > cpu7/topology/thread_siblings_list: 6-7
> > >
> > >
> > > I'm guessing this is an AMD bulldozer like machine?
> >
> > /proc/cpuinfo thinks otherwise:
> >
> > processor : 0
> > vendor_id : GenuineIntel
> > cpu family : 6
> > model : 60
> > model name : Intel(R) Core(TM) i7-4710MQ CPU @ 2.50GHz
>
> Weird, I've never seen an Intel box do that before... hpa, any idea? or
> is this just one weird BIOS.
;-)
It is a Lenovo W541 laptop, for whatever that might be worth. Roughly
on year old.
Thanx, Paul
