Hi Thomas, FYI, the error/warning still remains. tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 0c18f29aae7ce3dadd26d8ee3505d07cc982df75 commit: 6e799cb69a70eedbb41561b750f7180c12cff280 mm/highmem: Provide and use CONFIG_DEBUG_KMAP_LOCAL date: 7 months ago config: arc-randconfig-r014-20210622 (attached as .config) compiler: arc-elf-gcc (GCC) 9.3.0 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://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 6e799cb69a70eedbb41561b750f7180c12cff280 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arc 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 <command-line>: arch/arc/mm/highmem.c: In function 'kmap_init': 319 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) | ^ include/linux/compiler_types.h:300:4: note: in definition of macro '__compiletime_assert' 300 | prefix ## suffix(); \ | ^~~~~~ include/linux/compiler_types.h:319:2: note: in expansion of macro '_compiletime_assert' 319 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) | ^~~~~~~~~~~~~~~~~~~ include/linux/build_bug.h:39:37: note: in expansion of macro 'compiletime_assert' 39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) | ^~~~~~~~~~~~~~~~~~ include/linux/build_bug.h:50:2: note: in expansion of macro 'BUILD_BUG_ON_MSG' 50 | BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition) | ^~~~~~~~~~~~~~~~ arch/arc/mm/highmem.c:69:2: note: in expansion of macro 'BUILD_BUG_ON' 69 | BUILD_BUG_ON(FIX_KMAP_SLOTS > PTRS_PER_PTE); | ^~~~~~~~~~~~ vim +/__compiletime_assert_226 +319 include/linux/compiler_types.h eb5c2d4b45e3d2 Will Deacon 2020-07-21 305 eb5c2d4b45e3d2 Will Deacon 2020-07-21 306 #define _compiletime_assert(condition, msg, prefix, suffix) \ eb5c2d4b45e3d2 Will Deacon 2020-07-21 307 __compiletime_assert(condition, msg, prefix, suffix) eb5c2d4b45e3d2 Will Deacon 2020-07-21 308 eb5c2d4b45e3d2 Will Deacon 2020-07-21 309 /** eb5c2d4b45e3d2 Will Deacon 2020-07-21 310 * compiletime_assert - break build and emit msg if condition is false eb5c2d4b45e3d2 Will Deacon 2020-07-21 311 * @condition: a compile-time constant condition to check eb5c2d4b45e3d2 Will Deacon 2020-07-21 312 * @msg: a message to emit if condition is false eb5c2d4b45e3d2 Will Deacon 2020-07-21 313 * eb5c2d4b45e3d2 Will Deacon 2020-07-21 314 * In tradition of POSIX assert, this macro will break the build if the eb5c2d4b45e3d2 Will Deacon 2020-07-21 315 * supplied condition is *false*, emitting the supplied error message if the eb5c2d4b45e3d2 Will Deacon 2020-07-21 316 * compiler has support to do so. eb5c2d4b45e3d2 Will Deacon 2020-07-21 317 */ eb5c2d4b45e3d2 Will Deacon 2020-07-21 318 #define compiletime_assert(condition, msg) \ eb5c2d4b45e3d2 Will Deacon 2020-07-21 @319 _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) eb5c2d4b45e3d2 Will Deacon 2020-07-21 320 :::::: The code at line 319 was first introduced by commit :::::: eb5c2d4b45e3d2d5d052ea6b8f1463976b1020d5 compiler.h: Move compiletime_assert() macros into compiler_types.h :::::: TO: Will Deacon <will(a)kernel.org&gt; :::::: CC: Will Deacon <will(a)kernel.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org