Re: BIOS bug, APIC version if 0 for CPU#0

From: Justin Mattock
Date: Tue Apr 22 2008 - 10:36:21 EST


On Tue, Apr 22, 2008 at 1:49 PM, Kasper Sandberg <lkml@xxxxxxxxxxx> wrote:
> On Tue, 2008-04-22 at 06:10 +0000, Justin Mattock wrote:
> > On Tue, Apr 22, 2008 at 5:21 AM, Jacek Luczak <difrost.kernel@xxxxxxxxx> wrote:
> > > Hi,
> > >
> > >
> > > > Hello;
> > > > with the latest git on a macbook the system can barely boot without
> > > > freezing, a work around for me at leat is either disable smp, or once
> > > > booted turn on glxgears,or compiling the kernel i.g. when using the
> > > > processors I'm not receiving a freeze, only when everything starts
> > > > lowering down. in dmesg I'm noticing BIOS bug, APIC version is 0 for
> > > > CPU#0! fixing up to 0x10. (tell you're hw vendor) could this be the
> > > > reason for the system freezes?,
> > >
> > > I don't think so. On my machine there's no freezes with latest git and:
> > > ACPI: LAPIC (acpi_id[0x00] lapic_id[0x00] enabled)
> > > BIOS bug, APIC version is 0 for CPU#0! fixing up to 0x10. (tell your hw vendor)
> > > ACPI: LAPIC (acpi_id[0x01] lapic_id[0x01] enabled)
> > > BIOS bug, APIC version is 0 for CPU#0! fixing up to 0x10. (tell your hw vendor)
> > >
> > > I've got exactly the same messages.
> >
> > Are you using a macbook aswell?
> >
> > >
> > >
> > > > also I didnt have a camera handy on me
> > > > but the screen spit out = Bug spinlock lockup on CPU#0
> > > > swapper/0. c17fa7c0 PID 0, comm: swapper not tainted.
> > >
> > > Can you try to write down more of those bug messages?
> >
> > Yeah,
> >
> > >
> > >
> > > > I dont have a problem disabling smp, except when I cat /proc/cpuinfo I
> > > > don't see anything about my cores.
> > >
> > > What exactly you expect to see in /proc/cpuinfp while smp is disabled?
> >
> > under smp I see cpu cores. disabling smp I dont see cpu cores, under
> > cat /proc/cpuinfo.
>
> well.. SMP is kindof support for multiple processors, be it in one
> socket, or multiple sockets.. without SMP you will only be able to use 1
> of your X cores.

Yeah disabling smp is not a good idea on a macbook pro, performace is horrible.

> >
> >
> > >
> > >
> > > > I know this is a stupid question
> > > > but will it hurt the system if smp is disabled
> > > > for the macbook pro ati chipset.?
> > >
> > > No it won't.
> > >
> > > -Jacek
> > >
> >
> > Cool as long as the system Is o.k. disabling smp.
> It is.. but with the limitations outlined above.
> > What about x86: PAT
> > support is disabled. how do I enable this option?
> > regards;
> >
>
>
Thanks for the feedback, well I guess this would be either a
regression or a bug. I think the best would be to have somebody else
with a macbook pro 15' ati chipset confirm this freezeing as well,
before going out and jumping the gun, and filing a bug report.
regards;


--
Justin P. Mattock
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