Re: [PATCH v2 1/5] x86/topology: Export helper to get CPU number from APIC ID
From: Yazen Ghannam
Date: Mon Jul 01 2024 - 13:51:57 EST
On Fri, Jun 28, 2024 at 04:45:35PM +0200, Borislav Petkov wrote:
> On Fri, Jun 28, 2024 at 10:15:42AM -0400, Yazen Ghannam wrote:
> > Thanks for the tip. It looks to me that SMP and X86_LOCAL_APIC are
> > generally independent.
>
> They are?
>
> config X86_LOCAL_APIC
> def_bool y
> depends on X86_64 || SMP
> ^^^^^^^ ^^^
>
Right, SMP does not depend on X86_LOCAL_APIC. Otherwise, there would be
a circular dependency here.
X86_LOCAL_APIC depends on the logical OR of a bunch of options. So it
depends on "any one" of the options to be enabled. But it doesn't need
all of them.
config UP_LATE_INIT
def_bool y
depends on !SMP && X86_LOCAL_APIC
^^^^^^^^^^^^
This shows that X86_LOCAL_APIC doesn't have a hard dependency on SMP.
Otherwise, this option would never work.
Thanks,
Yazen