[akpm-mm:mm-new 332/339] include/linux/huge_mm.h:591:16: error: unused variable 'folio'

[kernel test robot <lkp@intel.com>]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-new
head:   0d1fe06d55b12fa3b8907412d97541b2b7eff16e
commit: c0b55300a1dec35aa8bad62ba520e368c9b1f041 [332/339] huge_memory: return -EINVAL in folio split functions when THP is disabled
config: nios2-randconfig-001-20250905 (https://download.01.org/0day-ci/archive/20250905/202509052234.q4rNraUm-lkp@intel.com/config)
compiler: nios2-linux-gcc (GCC) 10.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250905/202509052234.q4rNraUm-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202509052234.q4rNraUm-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from include/linux/mm.h:1081,
                    from include/linux/pid_namespace.h:7,
                    from include/linux/ptrace.h:10,
                    from arch/nios2/include/uapi/asm/elf.h:24,
                    from arch/nios2/include/asm/elf.h:9,
                    from include/linux/elf.h:6,
                    from include/linux/module.h:20,
                    from lib/test_bitops.c:10:
   include/linux/huge_mm.h: In function 'split_huge_page_to_list_to_order':
>> include/linux/huge_mm.h:591:16: error: unused variable 'folio' [-Werror=unused-variable]
     591 |  struct folio *folio = page_folio(page);
         |                ^~~~~
   include/linux/huge_mm.h: In function 'split_huge_page':
   include/linux/huge_mm.h:598:16: error: unused variable 'folio' [-Werror=unused-variable]
     598 |  struct folio *folio = page_folio(page);
         |                ^~~~~
   cc1: all warnings being treated as errors


vim +/folio +591 include/linux/huge_mm.h

   581	
   582	static inline bool
   583	can_split_folio(struct folio *folio, int caller_pins, int *pextra_pins)
   584	{
   585		return false;
   586	}
   587	static inline int
   588	split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
   589			unsigned int new_order)
   590	{
 > 591		struct folio *folio = page_folio(page);
   592	
   593		VM_WARN_ON_ONCE_FOLIO(1, folio);
   594		return -EINVAL;
   595	}
   596	static inline int split_huge_page(struct page *page)
   597	{
   598		struct folio *folio = page_folio(page);
   599	
   600		VM_WARN_ON_ONCE_FOLIO(1, folio);
   601		return -EINVAL;
   602	}
   603	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki