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

From: Michal Hocko
Date: Thu Feb 22 2018 - 02:11:11 EST


On Thu 22-02-18 14:30:57, Stephen Rothwell wrote:
> Hi Andrew,
>
> [As reported by Randy for uml ...]
>
> After merging the akpm-current tree, today's linux-next build (sparc
> defconfig) failed like this:
>
> /home/sfr/next/next/mm/page_alloc.c: In function 'memmap_init_zone':
> /home/sfr/next/next/mm/page_alloc.c:5450:11: error: implicit declaration of function 'memblock_next_valid_pfn'; did you mean 'memblock_virt_alloc_low'? [-Werror=implicit-function-declaration]
> pfn = memblock_next_valid_pfn(pfn, end_pfn) - 1;
> ^~~~~~~~~~~~~~~~~~~~~~~
> memblock_virt_alloc_low

This is interesting. I thought that IS_ENABLED(CONFIG_HAVE_MEMBLOCK)
would have the same meaning as ifdef CONFIG_HAVE_MEMBLOCK so the branch
will never be considered. If that is not the case then I would rather
reintroduce that ifdef. We already have those in the function anyway.
--
Michal Hocko
SUSE Labs