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

On Tue, Feb 2, 2021 at 10:13 AM Stephen Rothwell [off-list ref] 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@ellerman.id.au 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@linux-m68k.org

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