Hi Yi, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on mmotm/master] url: https://github.com/0day-ci/linux/commits/Yi-Wang/mm-slab-Use-kmem_cache_zalloc-instead-of-kmem_cache_alloc-with-flag-GFP_ZERO/20200617-151513 base: git://git.cmpxchg.org/linux-mmotm.git master config: x86_64-rhel-7.6 (attached as .config) compiler: gcc-9 (Debian 9.3.0-13) 9.3.0 reproduce (this is a W=1 build): # save the attached .config to linux build tree make W=1 ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>, old ones prefixed by <<): >> drivers/mtd/ubi/attach.o: warning: objtool: ubi_add_to_av()+0x1c4: unreachable instruction -- >> mm/slab_common.o: warning: objtool: create_kmalloc_caches()+0x44: unreachable instruction -- >> fs/btrfs/free-space-cache.o: warning: objtool: btrfs_trim_block_group()+0x201: unreachable instruction -- >> drivers/acpi/acpica/psutils.o: warning: objtool: acpi_ps_create_scope_op()+0x12: unreachable instruction -- >> fs/fuse/dev.o: warning: objtool: fuse_force_forget()+0x42: unreachable instruction --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org