Re: [kernel 3.13.0-06058-g2d08cd0] Strange ACPI error messages

Rafael J. Wysocki
2014-01-25T22:17:28Z

On Saturday, January 25, 2014 02:18:17 PM Henrique de Moraes Holschuh wrote:
> On Sat, 25 Jan 2014, Rafael J. Wysocki wrote:
> > On Saturday, January 25, 2014 02:53:24 PM Rafael J. Wysocki wrote:
> > > On Saturday, January 25, 2014 11:03:09 AM Jörg Otte wrote:
> > > > Kernel 3.13.0-06058-g2d08cd0 displays following errors on the console:
> > > >
> > > > ACPI: \_PR_.CPU4: failed to get CPU APIC ID.
> > > > ACPI: \_PR_.CPU5: failed to get CPU APIC ID.
> > > > ACPI: \_PR_.CPU6: failed to get CPU APIC ID.
> > > > ACPI: \_PR_.CPU7: failed to get CPU APIC ID.
> > > >
> > > > I don't have CPUs 4..7! Error messages regarding not existing
> > > > CPUs should not be displayed.
> > > > kernel 3.13.0-05617-g3aacd62 and before did'nt show this messages.
> > > >
> > > > This is a regression. I never saw this messages before.
> > >
> > > Does your system show any other suspicious symptoms or are you worried about
> > > those messages only?
> >
> > Gerry, this is your commit b981513f806d (ACPI / scan: bail out early if failed
> > to parse APIC ID for CPU). Apparently, the BIOS has room for 4 CPUs more than
> > there actually are in the system. Maybe we can reduce the log level of those
> > messages to avoid ringing bells unnecessarily?
>
> It is standard practice (at least in SuperMicro boxes, but I've also seen it
> elsewhere) for the BIOS to have ACPI tables mentioning all cores supported
> by the biggest core-count CPU topology possible by the motherboard. The
> cores you don't have are reported as if they were hotpluggable but absent,
> even if they will *never* show up at runtime. Meh.
>
> So yes, such warnings will get annoying *very* quickly.

Well, what about using acpi_handle_debug() in there, then?

--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.