PROBLEM: 4.15.0-rc3 APIC causes lockups on Core 2 Duo laptop

[Thomas Gleixner]

On Sat, 23 Dec 2017, Dexuan Cui wrote:

> > From: Alexandru Chirvasitu [mailto:achirvasub at gmail.com]
> > Sent: Friday, December 22, 2017 14:29
> > 
> > The output of that precise command run just now on a freshly-compiled
> > copy of that commit is attached.
> > 
> > On Fri, Dec 22, 2017 at 09:31:28PM +0000, Dexuan Cui wrote:
> > > > From: Alexandru Chirvasitu [mailto:achirvasub at gmail.com]
> > > > Sent: Friday, December 22, 2017 06:21
> > > >
> > > > In the absence of logs, the best I can do at the moment is attach a
> > > > picture of the screen I am presented with on the apic=debug boot
> > > > attempt.
> > > > Alex
> > >
> > > The panic happens in irq_matrix_assign_system+0x4e/0xd0 in your picture.
> > > IMO we should find which line of code causes the panic. I suppose
> > > "objdump -D kernel/irq/matrix.o" can help to do that.
> > >
> > > Thanks,
> > > -- Dexuan
> 
> The BUG_ON panic happens at line 147:
>                    BUG_ON(!test_and_clear_bit(bit, cm->alloc_map));
> 
> I'm sure Thomas and Dou know it better than me. 

I'll have a look after the holidays.

Thanks,

	tglx