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 Caused by commit c3d8f8809701 ("mm: page_alloc: skip over regions of invalid pfns on UMA") I have applied the following patch for today: From: Stephen Rothwell Date: Thu, 22 Feb 2018 14:20:45 +1100 Subject: [PATCH] mm: page_alloc: skip over regions of invalid pfns on UMA fix Signed-off-by: Stephen Rothwell --- include/linux/memblock.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/include/linux/memblock.h b/include/linux/memblock.h index c2f1a6996fad..90e6845f44be 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -423,6 +423,11 @@ static inline phys_addr_t memblock_alloc(phys_addr_t size, phys_addr_t align) { return 0; } +static inline unsigned long memblock_next_valid_pfn(unsigned long pfn, + unsigned long max_pfn) +{ + return pfn; +} #endif /* CONFIG_HAVE_MEMBLOCK */ #endif /* __KERNEL__ */ -- 2.16.1 -- Cheers, Stephen Rothwell