tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   7def1ef0f72c3ebe3e42467d2f73c4e56153fa49
commit: db22c0ad9503eda042475aca2675cdce55249b4b [6698/6711] mm/madvise: introduce process_madvise() syscall: an external memory hinting API
config: mips-ip27_defconfig (attached as .config)
compiler: mips64-linux-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
        git checkout db22c0ad9503eda042475aca2675cdce55249b4b
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day GCC_VERSION=9.3.0 make.cross ARCH=mips 

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

All warnings (new ones prefixed by >>):

>> <stdin>:1520:2: warning: #warning syscall process_madvise not implemented [-Wcpp]
--
>> <stdin>:1520:2: warning: #warning syscall process_madvise not implemented [-Wcpp]
--
>> <stdin>:1520:2: warning: #warning syscall process_madvise not implemented [-Wcpp]

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