Re: [linux-next:master 5933/6583] include/linux/page_ext.h:131:20: error: call to undeclared function 'page_to_section'; ISO C99 and later do not support implicit function declarations

[Luiz Capitulino <luizcap@redhat.com>]

On 2025-02-26 09:10, Arnd Bergmann wrote:
> On Wed, Feb 26, 2025, at 10:46, kernel test robot wrote:
>> commit: a2d6e9c1a867bb9f13943cb8483e2ab85b630bcd [5933/6583] mm:
>> page_ext: add an iteration API for page extensions
>> config: i386-buildonly-randconfig-004-20250226
> 
>>
>>     In file included from arch/x86/kernel/asm-offsets.c:14:
>>     In file included from include/linux/suspend.h:5:
>>     In file included from include/linux/swap.h:9:
>>     In file included from include/linux/memcontrol.h:21:
>>     In file included from include/linux/mm.h:8:
>>     In file included from include/linux/pgalloc_tag.h:12:
>>>> include/linux/page_ext.h:131:20: error: call to undeclared function 'page_to_section'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
>>       131 |         iter->start_pfn = page_to_pfn(page);
>>           |                           ^
>>     include/asm-generic/memory_model.h:64:21: note: expanded from macro
>> 'page_to_pfn'
>>        64 | #define page_to_pfn __page_to_pfn
> 
> I'm getting this on all configurations that set CONFIG_SPARSEMEM
> but not CONFIG_SPARSEMEM_VMMEMMAP.

Oh, thanks. I didn't build with CONFIG_SPARSEMEM_VMEMMAP=n.

> There is also a possible problem with linux/page_ext.h
> including pgtable.h and mmzone.h, which I think can lead
> to circular header inclusions with linux/mm.h.

Thanks, I'll look into this.

Andrew, I think you'll have to drop this for now. I may not
have the time to look into this this week.