Hi Peter, Thank you for the patch! Yet something to improve: [auto build test ERROR on cb0e52b7748737b2cf6481fdd9b920ce7e1ebbdf] url: https://github.com/0day-ci/linux/commits/Peter-Oskolkov/sched-mm-x86-uacc... base: cb0e52b7748737b2cf6481fdd9b920ce7e1ebbdf config: x86_64-randconfig-c007-20211121 (attached as .config) 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/e455791cacec2b140558a717d2b8b07f5... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Peter-Oskolkov/sched-mm-x86-uaccess-implement-User-Managed-Concurrency-Groups/20211122-052209 git checkout e455791cacec2b140558a717d2b8b07f5561a251 # save the attached .config to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): In file included from <built-in>:1: u64 state_ts; /* r/w */ ^ u32 next_tid; /* r */ ^ ./usr/include/linux/umcg.h:93:2: error: unknown type name 'u32' u32 flags; /* Reserved; must be zero. */ ^ ./usr/include/linux/umcg.h:101:2: error: unknown type name 'u64' u64 idle_workers_ptr; /* r/w */ ^ ./usr/include/linux/umcg.h:107:2: error: unknown type name 'u64' u64 idle_server_tid_ptr; /* r */ ^ 5 errors generated. --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org