Hi Johannes, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on akpm-mm/mm-everything] url: https://github.com/intel-lab-lkp/linux/commits/Johannes-Weiner/mm-mempolicy-N-M-interleave-policy-for-tiered-memory-nodes/20220608-012652 base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything config: x86_64-randconfig-a003 (https://download.01.org/0day-ci/archive/20220609/202206090708.jaGUnz8e-lkp@xxxxxxxxx/config) compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project b92436efcb7813fc481b30f2593a4907568d917a) 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/intel-lab-lkp/linux/commit/876d8daa0642d35f71ff504eeb3be4b950339a45 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Johannes-Weiner/mm-mempolicy-N-M-interleave-policy-for-tiered-memory-nodes/20220608-012652 git checkout 876d8daa0642d35f71ff504eeb3be4b950339a45 # save the config file mkdir build_dir && cp config build_dir/.config 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 where applicable Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): >> mm/mempolicy.c:1890:11: warning: variable 'next' is used uninitialized whenever function 'next_node_tier' is called [-Wsometimes-uninitialized] unsigned next, start = nid; ~~~~~~~~~^~~~ mm/mempolicy.c:1893:23: note: uninitialized use occurs here next = next_node_in(next, policy->nodes); ^~~~ include/linux/nodemask.h:278:46: note: expanded from macro 'next_node_in' #define next_node_in(n, src) __next_node_in((n), &(src)) ^ mm/mempolicy.c:1890:15: note: initialize the variable 'next' to silence this warning unsigned next, start = nid; ^ = 0 1 warning generated. vim +1890 mm/mempolicy.c 1887 1888 static unsigned next_node_tier(int nid, struct mempolicy *policy, bool toptier) 1889 { > 1890 unsigned next, start = nid; 1891 1892 do { 1893 next = next_node_in(next, policy->nodes); 1894 if (next == MAX_NUMNODES) 1895 break; 1896 if (toptier == node_is_toptier(next)) 1897 break; 1898 } while (next != start); 1899 return next; 1900 } 1901 -- 0-DAY CI Kernel Test Service https://01.org/lkp