Hi Hui, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on mmotm/master] url: https://github.com/0day-ci/linux/commits/Hui-Su/mm-shmem-c-make-shmem_map... base: git://git.cmpxchg.org/linux-mmotm.git master config: arm-randconfig-s032-20201113 (attached as .config) compiler: arm-linux-gnueabi-gcc (GCC) 9.3.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # apt-get install sparse # sparse version: v0.6.3-107-gaf3512a6-dirty # https://github.com/0day-ci/linux/commit/0434762d5523a3d702cd589a7f8e3771f... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Hui-Su/mm-shmem-c-make-shmem_mapping-inline/20201113-215549 git checkout 0434762d5523a3d702cd589a7f8e3771fee7b3b2 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=arm If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; "sparse warnings: (new ones prefixed by >>)" mm/filemap.c: note: in included file: >> include/linux/shmem_fs.h:66:33: sparse: sparse: marked inline, but without a definition >> include/linux/shmem_fs.h:66:33: sparse: sparse: marked inline, but without a definition >> include/linux/shmem_fs.h:66:33: sparse: sparse: marked inline, but without a definition -- mm/truncate.c: note: in included file: >> include/linux/shmem_fs.h:66:33: sparse: sparse: marked inline, but without a definition >> include/linux/shmem_fs.h:66:33: sparse: sparse: marked inline, but without a definition >> include/linux/shmem_fs.h:66:33: sparse: sparse: marked inline, but without a definition -- mm/memfd.c: note: in included file: >> include/linux/shmem_fs.h:66:33: sparse: sparse: marked inline, but without a definition vim +66 include/linux/shmem_fs.h 48 49 /* 50 * Functions in mm/shmem.c called directly from elsewhere: 51 */ 52 extern const struct fs_parameter_description shmem_fs_parameters; 53 extern int shmem_init(void); 54 extern int shmem_init_fs_context(struct fs_context *fc); 55 extern struct file *shmem_file_setup(const char *name, 56 loff_t size, unsigned long flags); 57 extern struct file *shmem_kernel_file_setup(const char *name, loff_t size, 58 unsigned long flags); 59 extern struct file *shmem_file_setup_with_mnt(struct vfsmount *mnt, 60 const char *name, loff_t size, unsigned long flags); 61 extern int shmem_zero_setup(struct vm_area_struct *); 62 extern unsigned long shmem_get_unmapped_area(struct file *, unsigned long addr, 63 unsigned long len, unsigned long pgoff, unsigned long flags); 64 extern int shmem_lock(struct file *file, int lock, struct user_struct *user); 65 #ifdef CONFIG_SHMEM > 66 extern inline bool shmem_mapping(struct address_space *mapping); 67 #else 68 static inline bool shmem_mapping(struct address_space *mapping) 69 { 70 return false; 71 } 72 #endif /* CONFIG_SHMEM */ 73 extern void shmem_unlock_mapping(struct address_space *mapping); 74 extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, 75 pgoff_t index, gfp_t gfp_mask); 76 extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end); 77 extern int shmem_unuse(unsigned int type, bool frontswap, 78 unsigned long *fs_pages_to_unuse); 79 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org