tree: https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-5.13.y-rt-testing head: 2eb9270f1294b849cb310d6fb1f2675dfb3f9c75 commit: 2d1c3636a727647cffb1185ccac6897e551a4071 [205/226] sched: Add support for lazy preemption config: mips-randconfig-r032-20210709 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 8d69635ed9ecf36fd0ca85906bfde17949671cbe) 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://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git/com... git remote add linux-rt-devel https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git git fetch --no-tags linux-rt-devel linux-5.13.y-rt-testing git checkout 2d1c3636a727647cffb1185ccac6897e551a4071 # save the attached .config to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross O=build_dir ARCH=mips SHELL=/bin/bash kernel/sched/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): kernel/sched/core.c:2964:13: warning: variable 'rq' set but not used struct rq ^ kernel/sched/core.c:2954:20: warning: unused function 'rq_has_pinned_tasks' static inline bool rq_has_pinned_tasks(struct rq ^ kernel/sched/core.c:4858:20: warning: unused function 'sched_tick_start' static inline void sched_tick_start(int cpu) { } ^ kernel/sched/core.c:4859:20: warning: unused function 'sched_tick_stop' static inline void sched_tick_stop(int cpu) { } ^ static inline int preemptible_lazy(void) ^ fatal error: error in backend: Nested variants found in inline asm string: ' .set push .set noat .set push .set arch=r4000 .if ( 0x00 ) != -1)) 0x00 ) != -1)) : ($( static struct ftrace_branch_data __attribute__((__aligned__(4))) __attribute__((__section__("_ftrace_branch"))) __if_trace = $( .func = __func__, .file = "arch/mips/include/asm/cmpxchg.h", .line = 163, $); 0x00 ) != -1)) : $))) ) && ( 0 ); .set push; .set mips64r2; .rept 1; sync 0x00; .endr; .set pop; .else; ; .endif 1: ll $0, $2 # __cmpxchg_asm bne $0, ${3:z}, 2f .set pop move $$1, ${4:z} .set arch=r4000 sc $$1, $1 beqz $$1, 1b .set pop 2: .if ( 0x00 ) != -1)) 0x00 ) != -1)) : ($( static struct ftrace_branch_data __attribute__((__aligned__(4))) __attribute__((__section__("_ftrace_branch"))) __if_trace = $( .func = __func__, .file = "arch/mips/include/asm/cmpxchg.h", .line = 163, $); 0x00 ) != -1)) : $))) ) && ( 0 ); .set push; .set mips64r2; .rept 1; sync 0x00; .endr; .set pop; .else; ; .endif ' clang-13: error: clang frontend command failed with exit code 70 (use -v to see invocation) clang version 13.0.0 (git://gitmirror/llvm_project 8d69635ed9ecf36fd0ca85906bfde17949671cbe) Target: mipsel-unknown-linux-gnu Thread model: posix InstalledDir: /opt/cross/clang-8d69635ed9/bin clang-13: note: diagnostic msg: Makefile arch block certs crypto drivers fs include init ipc kernel lib mm samples scripts security sound source usr virt vim +/preemptible_lazy +5459 kernel/sched/core.c 5458 5460 { 5461 return 1; 5462 } 5463 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org