tree: https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-5.10.y-rt-rebase head: d57d7d09825f034b4ec37457940c83158c3731c8 commit: 1ef83f899b95ba6a91a1bedaf8cb4129e63b4633 [83/269] printk: use seqcount_latch for clear_seq config: x86_64-randconfig-a016-20201217 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project cee1e7d14f4628d6174b33640d502bff3b54ae45) 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://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-5.10.y-rt-rebase git checkout 1ef83f899b95ba6a91a1bedaf8cb4129e63b4633 # 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 >>): void latched_seq_write(struct latched_seq *ls, u64 val) ^ kernel/printk/printk.c:469:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void latched_seq_write(struct latched_seq *ls, u64 val) ^ static u64 latched_seq_read_nolock(struct latched_seq *ls) ^ kernel/printk/printk.c:478:1: note: declare 'static' if the function is not intended to be used outside of this translation unit u64 latched_seq_read_nolock(struct latched_seq *ls) ^ static 2 warnings generated. vim +/latched_seq_write +469 kernel/printk/printk.c 467 468 /* Must be called under logbuf_lock. */ 470 { 471 raw_write_seqcount_latch(&ls->latch); 472 ls->val[0] = val; 473 raw_write_seqcount_latch(&ls->latch); 474 ls->val[1] = val; 475 } 476 477 /* Can be called from any context. */ 479 { 480 unsigned int seq; 481 unsigned int idx; 482 u64 val; 483 484 do { 485 seq = raw_read_seqcount_latch(&ls->latch); 486 idx = seq & 0x1; 487 val = ls->val[idx]; 488 } while (read_seqcount_latch_retry(&ls->latch, seq)); 489 490 return val; 491 } 492 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org