Hi Zach, Thank you for the patch! Yet something to improve: [auto build test ERROR on hnaz-mm/master] url: https://github.com/intel-lab-lkp/linux/commits/Zach-O-Keefe/mm-userspace-hugepage-collapse/20220410-215722 base: https://github.com/hnaz/linux-mm master config: mips-randconfig-r002-20220410 (https://download.01.org/0day-ci/archive/20220411/202204110059.a0PLTrVC-lkp@xxxxxxxxx/config) compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 256c6b0ba14e8a7ab6373b61b7193ea8c0a3651c) 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 # install mips cross compiling tool for clang build # apt-get install binutils-mips-linux-gnu # https://github.com/intel-lab-lkp/linux/commit/4f4775a3e4a722525787b2c309032810356473c2 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Zach-O-Keefe/mm-userspace-hugepage-collapse/20220410-215722 git checkout 4f4775a3e4a722525787b2c309032810356473c2 # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=mips SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> All errors (new ones prefixed by >>): >> mm/madvise.c:62:7: error: use of undeclared identifier 'MADV_COLLAPSE' case MADV_COLLAPSE: ^ mm/madvise.c:1055:7: error: use of undeclared identifier 'MADV_COLLAPSE' case MADV_COLLAPSE: ^ 2 errors generated. vim +/MADV_COLLAPSE +62 mm/madvise.c 44 45 /* 46 * Any behaviour which results in changes to the vma->vm_flags needs to 47 * take mmap_lock for writing. Others, which simply traverse vmas, need 48 * to only take it for reading. 49 */ 50 static int madvise_need_mmap_write(int behavior) 51 { 52 switch (behavior) { 53 case MADV_REMOVE: 54 case MADV_WILLNEED: 55 case MADV_DONTNEED: 56 case MADV_DONTNEED_LOCKED: 57 case MADV_COLD: 58 case MADV_PAGEOUT: 59 case MADV_FREE: 60 case MADV_POPULATE_READ: 61 case MADV_POPULATE_WRITE: > 62 case MADV_COLLAPSE: 63 return 0; 64 default: 65 /* be safe, default to 1. list exceptions explicitly */ 66 return 1; 67 } 68 } 69 -- 0-DAY CI Kernel Test Service https://01.org/lkp