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Sender: Ingo Molnar <mingo.kernel.org@gmail.com>
Date: Tue, 27 Feb 2024 10:19:07 +0100
From: Ingo Molnar <mingo@kernel.org>
To: Borislav Petkov <bp@alien8.de>
Cc: linux-kernel@vger.kernel.org, linux-tip-commits@vger.kernel.org,
	Thomas Gleixner <tglx@linutronix.de>, x86@kernel.org
Subject: Re: [tip: x86/apic] smp: Provide 'setup_max_cpus' definition on UP
 too
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* Borislav Petkov <bp@alien8.de> wrote:

> On Mon, Feb 26, 2024 at 11:48:06AM -0000, tip-bot2 for Ingo Molnar wrote:
> > The following commit has been merged into the x86/apic branch of tip:
> > 
> > Commit-ID:     429bb0269058e2e1f4ab69a0d33d374933aa15b9
> > Gitweb:        https://git.kernel.org/tip/429bb0269058e2e1f4ab69a0d33d374933aa15b9
> > Author:        Ingo Molnar <mingo@kernel.org>
> > AuthorDate:    Mon, 26 Feb 2024 12:07:31 +01:00
> > Committer:     Ingo Molnar <mingo@kernel.org>
> > CommitterDate: Mon, 26 Feb 2024 12:13:40 +01:00
> > 
> > smp: Provide 'setup_max_cpus' definition on UP too
> > 
> > This was already defined locally by init/main.c, but let's make
> > it generic, as arch/x86/kernel/cpu/topology.c is going to make
> > use of it to have more uniform code.
> > 
> > [ Keep it a C variable, not a define, because there's
> >   some namespace overlap for the 'setup_max_cpus' token
> >   in existing function argument names. ]
> > 
> > Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
> > Cc: linux-kernel@vger.kernel.org
> > Signed-off-by: Ingo Molnar <mingo@kernel.org>
> > --
> > ---
> >  include/linux/smp.h | 2 ++
> >  init/main.c         | 1 -
> >  2 files changed, 2 insertions(+), 1 deletion(-)
> 
> That one needs some work:
> 
> $ grep setup_max_cpus 13-37-17-randconfig-x86_64-2517.log
> ...
> ./include/linux/smp.h:221:27: warning: ‘setup_max_cpus’ defined but not used [-Wunused-const-variable=]
> $ grep setup_max_cpus 13-37-17-randconfig-x86_64-2517.log  | wc -l
> 122
> 
> very noisy.

Yeah, a bit sad.

So I resolved this all with using #define and (first) fixing a namespace 
collision that broke with the #define:

  4c8a49854130 smp: Avoid 'setup_max_cpus' namespace collision/shadowing
  3c2f8859ae1c smp: Provide 'setup_max_cpus' definition on UP too
  6be4ec29685c x86/apic: Build the x86 topology enumeration functions on UP APIC builds too

Thanks,

	Ingo