tree: https://github.com/intel/linux-intel-lts.git 4.19/preempt-rt head: 952ccae1fdfe6717579ac5db4304ac55b34b72e9 commit: ad01e51437422285ac98eced7c7136b368bd2ffc [18579/22023] net: xfrm: fix compress vs decompress serialization config: x86_64-randconfig-a011-20210520 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project e84a9b9bb3051c35dea993cdad7b3d2575638f85) 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 # https://github.com/intel/linux-intel-lts/commit/ad01e51437422285ac98eced7... git remote add intel-linux-intel-lts https://github.com/intel/linux-intel-lts.git git fetch --no-tags intel-linux-intel-lts 4.19/preempt-rt git checkout ad01e51437422285ac98eced7c7136b368bd2ffc # 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: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): static DEFINE_LOCAL_IRQ_LOCK(ipcomp_scratches_lock); ^ 1 warning generated. vim +/ipcomp_scratches_lock +40 net/xfrm/xfrm_ipcomp.c 37 38 static DEFINE_MUTEX(ipcomp_resource_mutex); 39 static void * __percpu *ipcomp_scratches; 41 static int ipcomp_scratch_users; 42 static LIST_HEAD(ipcomp_tfms_list); 43 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org