Re: linux-next: build failure after merge of the akpm-current tree

[Geert Uytterhoeven]

On Tue, Feb 2, 2021 at 10:13 AM Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
> After merging the akpm-current tree, today's linux-next build (x86_64
> allnoconfig) failed like this:
>
> In file included from arch/x86/include/asm/page.h:76,
>                  from arch/x86/include/asm/thread_info.h:12,
>                  from include/linux/thread_info.h:56,
>                  from arch/x86/include/asm/preempt.h:7,
>                  from include/linux/preempt.h:78,
>                  from include/linux/spinlock.h:51,
>                  from include/linux/mmzone.h:8,
>                  from include/linux/gfp.h:6,
>                  from include/linux/slab.h:15,
>                  from include/linux/crypto.h:20,
>                  from arch/x86/kernel/asm-offsets.c:9:
> include/linux/mm.h: In function 'is_pinnable_page':
> include/asm-generic/memory_model.h:64:14: error: implicit declaration of function 'page_to_section'; did you mean 'present_section'? [-Werror=implicit-function-declaration]
>    64 |  int __sec = page_to_section(__pg);   \
>       |              ^~~~~~~~~~~~~~~
> include/asm-generic/memory_model.h:81:21: note: in expansion of macro '__page_to_pfn'
>    81 | #define page_to_pfn __page_to_pfn
>       |                     ^~~~~~~~~~~~~
> include/linux/mm.h:1134:15: note: in expansion of macro 'page_to_pfn'
>  1134 |   is_zero_pfn(page_to_pfn(page));
>       |               ^~~~~~~~~~~

In addition, noreply@xxxxxxxxxxxxxx reports for m68k/m5272c3_defconfig:

    include/linux/mm.h:1133:3: error: implicit declaration of function
'is_zero_pfn'; did you mean 'is_zero_ino'?
[-Werror=implicit-function-declaration]

is_zero_pfn() is only defined if CONFIG_MMU=y.

Hence using it in mm/gup.c in commit 3f509f6aef4bb868 ("mm/gup: migrate
pinned pages out of movable zone") breaks compilation of gup.c, too.


Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds