Re: [PATCH] fix ACPI induced voyager compile failure

[Ingo Molnar <mingo@elte.hu>]

* James Bottomley <James.Bottomley@HansenPartnership.com> wrote:

> On Thu, 2008-10-30 at 22:58 +0100, Ingo Molnar wrote:
> > * James Bottomley <James.Bottomley@HansenPartnership.com> wrote:
> > 
> > > >From c339b7cdc39399855ec07dfbff67304f9c7fa49a Mon Sep 17 00:00:00 2001
> > > From: James Bottomley <James.Bottomley@HansenPartnership.com>
> > > Date: Wed, 29 Oct 2008 10:58:13 -0500
> > > Subject: [VOYAGER] x86: don't pull asm/acpi.h into fixmap_32.h
> > > 
> > > If it's not needed it causes compile failures.
> > > 
> > > Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
> > > ---
> > >  arch/x86/include/asm/fixmap_32.h |    2 ++
> > >  1 files changed, 2 insertions(+), 0 deletions(-)
> > > 
> > > diff --git a/arch/x86/include/asm/fixmap_32.h b/arch/x86/include/asm/fixmap_32.h
> > > index 09f29ab..c3302ee 100644
> > > --- a/arch/x86/include/asm/fixmap_32.h
> > > +++ b/arch/x86/include/asm/fixmap_32.h
> > > @@ -25,7 +25,9 @@ extern unsigned long __FIXADDR_TOP;
> > >  
> > >  #ifndef __ASSEMBLY__
> > >  #include <linux/kernel.h>
> > > +#ifdef CONFIG_ACPI
> > >  #include <asm/acpi.h>
> > > +#endif
> > 
> > hm, that's quite ugly - such headers are supposed to be safe even if 
> > CONFIG_APIC is not turned on.
> > 
> > What kind of compiler failures are you getting, could you send the 
> > .config that triggers it? I'm curious what the real cause of the build 
> > failure is - the #ifdef you are adding seems to fix a symptom, not a 
> > real bug - and maybe we can do a better fix.
> 
> It's the problem of voyager wanting its own definition of
> phys_cpu_present_map.  acpi.h pulls in mpspec.h which contaminates the
> voyager_smp.c build.

i guess voyager could use physid_mask_t just fine?

physid_mask_t is MAX_APICS derived - but it should work out fine 
because AFAICS voyager has a maximum of 4 cpus (but definitely less 
than say 32), while MAX_APICS never goes below 256.

	Ingo