Hi Rocco,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on net/master]
[also build test ERROR on linus/master v5.14-rc3]
[cannot apply to net-next/master next-20210728]
[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/Rocco-Yue/net-ipv6-add-IFLA_RA_MTU-to-expose-mtu-value-in-the-RA-message/20210729-172047
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git fc16a5322ee6c30ea848818722eee5d352f8d127
config: parisc-randconfig-r032-20210728 (attached as .config)
compiler: hppa-linux-gcc (GCC) 10.3.0
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/c2c81e86202db50af376f5135ec853ad3f4deb82
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Rocco-Yue/net-ipv6-add-IFLA_RA_MTU-to-expose-mtu-value-in-the-RA-message/20210729-172047
        git checkout c2c81e86202db50af376f5135ec853ad3f4deb82
        # save the attached .config to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-10.3.0 make.cross O=build_dir ARCH=parisc SHELL=/bin/bash

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 >>):

   hppa-linux-ld: net/core/rtnetlink.o: in function `rtnl_fill_ifinfo.constprop.0.isra.0':
>> net/core/rtnetlink.o:(.text+0xa098): undefined reference to `inet6_dev_ramtu'

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