Hi Barry,

I love your patch! Yet something to improve:

[auto build test ERROR on kselftest/next]
[also build test ERROR on linus/master v5.10-rc1]
[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]

url:    https://github.com/0day-ci/linux/commits/Barry-Song/dma-mapping-provide-a-benchmark-for-streaming-DMA-mapping/20201101-182009
base:   https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git next
config: h8300-allyesconfig (attached as .config)
compiler: h8300-linux-gcc (GCC) 9.3.0
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/0day-ci/linux/commit/b9abda38be7f32b9420c27b6c24eff2e69defa87
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Barry-Song/dma-mapping-provide-a-benchmark-for-streaming-DMA-mapping/20201101-182009
        git checkout b9abda38be7f32b9420c27b6c24eff2e69defa87
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=h8300 

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

All errors (new ones prefixed by >>):

   h8300-linux-ld: kernel/dma/map_benchmark.o: in function `.L28':
   map_benchmark.c:(.text+0x283): undefined reference to `__udivdi3'
>> h8300-linux-ld: map_benchmark.c:(.text+0x2c1): undefined reference to `__udivdi3'
   h8300-linux-ld: map_benchmark.c:(.text+0x327): undefined reference to `__udivdi3'
   h8300-linux-ld: kernel/dma/map_benchmark.o: in function `.L26':
   map_benchmark.c:(.text+0x3d7): undefined reference to `__udivdi3'
   h8300-linux-ld: kernel/dma/map_benchmark.o: in function `.L44':
   map_benchmark.c:(.text+0x799): undefined reference to `__divdi3'
   h8300-linux-ld: kernel/dma/map_benchmark.o: in function `.L45':
   map_benchmark.c:(.text+0x7f5): undefined reference to `__divdi3'

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org