Hi Matthew,

I love your patch! Yet something to improve:

[auto build test ERROR on linus/master]
[also build test ERROR on v6.2-rc1]
[cannot apply to akpm-mm/mm-everything next-20221226]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Matthew-Wilcox-Oracle/mm-Remove-folio_pincount_ptr-and-head_compound_pincount/20230101-054709
patch link:    https://lore.kernel.org/r/20221231214610.2800682-9-willy%40infradead.org
patch subject: [PATCH 08/22] mm: Add folio_add_new_anon_rmap()
config: m68k-randconfig-r034-20230101
compiler: m68k-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/0cc724aed3b147aba93541bbf32dba2844155330
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Matthew-Wilcox-Oracle/mm-Remove-folio_pincount_ptr-and-head_compound_pincount/20230101-054709
        git checkout 0cc724aed3b147aba93541bbf32dba2844155330
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All error/warnings (new ones prefixed by >>):

>> mm/folio-compat.c:127:6: warning: no previous prototype for 'page_add_new_anon_rmap' [-Wmissing-prototypes]
     127 | void page_add_new_anon_rmap(struct page *page, struct vm_area_struct *vma,
         |      ^~~~~~~~~~~~~~~~~~~~~~
   mm/folio-compat.c: In function 'page_add_new_anon_rmap':
>> mm/folio-compat.c:132:16: error: implicit declaration of function 'folio_add_new_anon_rmap'; did you mean 'page_add_new_anon_rmap'? [-Werror=implicit-function-declaration]
     132 |         return folio_add_new_anon_rmap((struct folio *)page, vma, address);
         |                ^~~~~~~~~~~~~~~~~~~~~~~
         |                page_add_new_anon_rmap
   mm/folio-compat.c:132:16: error: 'return' with a value, in function returning void [-Werror=return-type]
     132 |         return folio_add_new_anon_rmap((struct folio *)page, vma, address);
         |                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   mm/folio-compat.c:127:6: note: declared here
     127 | void page_add_new_anon_rmap(struct page *page, struct vm_area_struct *vma,
         |      ^~~~~~~~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors


vim +132 mm/folio-compat.c

   126	
 > 127	void page_add_new_anon_rmap(struct page *page, struct vm_area_struct *vma,
   128			unsigned long address)
   129	{
   130		VM_BUG_ON_PAGE(PageTail(page), page);
   131	
 > 132		return folio_add_new_anon_rmap((struct folio *)page, vma, address);

-- 
0-DAY CI Kernel Test Service
https://01.org/lkp