Re: [PATCH] x86/smpboot: Make logical package management more robust

From: Thomas Gleixner
Date: Sat Dec 10 2016 - 14:16:26 EST


On Sat, 10 Dec 2016, Thomas Gleixner wrote:
> On Fri, 9 Dec 2016, Boris Ostrovsky wrote:
> > On 12/09/2016 06:02 PM, Boris Ostrovsky wrote:
> > > On 12/09/2016 05:06 PM, Thomas Gleixner wrote:
> > > > On Thu, 8 Dec 2016, Thomas Gleixner wrote:
> > > >
> > > > Boris, can you please verify if that makes the
> > > > topology_update_package_map() call which you placed into the Xen cpu
> > > > starting code obsolete ?
> > >
> > > Will do. I did test your patch but without removing
> > > topology_update_package_map() call. It complained about package IDs
> > > being wrong, but that's expected until I fix Xen part.
> >
> > Ignore my statement about earlier testing --- it was all on single-node
> > machines.
> >
> > Something is broken with multi-node on Intel, but failure modes are different.
> > Prior to this patch build_sched_domain() reports an error and pretty soon we
> > crash in scheduler (don't remember off the top of my head). With patch applied
> > I crash mush later, when one of the drivers does kmalloc_node(..,
> > cpu_to_node(cpu)) and cpu_to_node() returns 1, which should never happen
> > ("x86: Booted up 1 node, 32 CPUs" is reported, for example).
>
> Hmm. But the cpu_to_node() association is unrelated to the logical package
> management.

Just came to my mind after hitting send. We had the whole persistent cpuid
to nodeid association work merged in 4.9. So that might be related.

Thanks,

tglx