linux-kernel - Re: [PATCH] x86: hide unused allocate_percpu_fixmap

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Date:   Sat, 30 Dec 2017 09:36:59 +0100
From:   Ingo Molnar <mingo@...nel.org>
To:     Arnd Bergmann <arnd@...db.de>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>, x86@...nel.org,
        Andy Lutomirski <luto@...nel.org>,
        Borislav Petkov <bp@...e.de>,
        Peter Zijlstra <peterz@...radead.org>,
        Thomas Garnier <thgarnie@...gle.com>,
        Ricardo Neri <ricardo.neri-calderon@...ux.intel.com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] x86: hide unused allocate_percpu_fixmap_ptes


* Arnd Bergmann <arnd@...db.de> wrote:

> The new function is not always used, causing a warning whenever
> CONFIG_CPU_SUP_INTEL is disabled:
> 
> arch/x86/kernel/cpu/common.c:522:20: error: 'allocate_percpu_fixmap_ptes' defined but not used [-Werror=unused-function]
> 
> Hide it in the same #ifdef.
> 
> Fixes: 3015f86f838c ("x86/fixmap: Add debugstore entries to cpu_entry_area")
> Signed-off-by: Arnd Bergmann <arnd@...db.de>
> ---
>  arch/x86/kernel/cpu/common.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
> index 6444f91e8d3c..6f354416a67f 100644
> --- a/arch/x86/kernel/cpu/common.c
> +++ b/arch/x86/kernel/cpu/common.c
> @@ -519,11 +519,13 @@ static DEFINE_PER_CPU_PAGE_ALIGNED(struct entry_stack_page,
>   * Force the population of PMDs for not yet allocated per cpu
>   * memory like debug store buffers.
>   */
> +#ifdef CONFIG_CPU_SUP_INTEL
>  static void __init allocate_percpu_fixmap_ptes(int idx, int pages)
>  {
>  	for (; pages; pages--, idx--)
>  		__set_fixmap(idx, 0, PAGE_NONE);
>  }
> +#endif

Ok, this fix should be moot as the allocate_percpu_fixmap_ptes() is gone from the 
latest versions of PTI.

Thanks,

	Ingo