tree: https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-5.6.y-rt head: c4a637d45e250c33f63c9397c17fc24fccfd902f commit: b5d91a45bf852758d3df48f9c77130166f45d939 [251/274] squashfs: make use of local lock in multi_cpu decompressor config: x86_64-randconfig-a001-20200602 (attached as .config) compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 2388a096e7865c043e83ece4e26654bd3d1a20d5) 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 x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu git checkout b5d91a45bf852758d3df48f9c77130166f45d939 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot All warnings (new ones prefixed by >>, old ones prefixed by <<): >> fs/squashfs/decompressor_multi_percpu.c:27:30: warning: unused variable 'stream_lock' [-Wunused-const-variable] static DEFINE_LOCAL_IRQ_LOCK(stream_lock); ^ 1 warning generated. vim +/stream_lock +27 fs/squashfs/decompressor_multi_percpu.c 26 > 27 static DEFINE_LOCAL_IRQ_LOCK(stream_lock); 28 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org