Hi Sebastian, [FYI, it's a private test report for your RFC patch.] [auto build test WARNING on next-20201215] [cannot apply to tip/perf/core linux/master block/for-next trace/for-next linus/master v5.10 v5.10-rc7 v5.10-rc6 v5.10] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Sebastian-Andrzej-Siewior/tracin... base: 9317f948b0b188b8d2fded75957e6d42c460df1b config: openrisc-randconfig-s031-20201216 (attached as .config) compiler: or1k-linux-gcc (GCC) 9.3.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # apt-get install sparse # sparse version: v0.6.3-184-g1b896707-dirty # https://github.com/0day-ci/linux/commit/afd5d9090ab105dae5830c2f050a30ec3... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Sebastian-Andrzej-Siewior/tracing-Merge-irqflags-preemt-counter-add-RT-bits/20201217-012430 git checkout afd5d9090ab105dae5830c2f050a30ec306d7201 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=openrisc 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/trace/trace.c: In function '__trace_puts': kernel/trace/trace.c:1001:6: warning: variable 'pc' set but not used [-Wunused-but-set-variable] 1001 | int pc; | ^~ kernel/trace/trace.c: In function '__trace_bputs': kernel/trace/trace.c:1056:6: warning: variable 'pc' set but not used [-Wunused-but-set-variable] 1056 | int pc; | ^~ kernel/trace/trace.c: At top level: kernel/trace/trace.c:3147:13: error: conflicting types for 'ftrace_trace_userstack' 3147 | static void ftrace_trace_userstack(struct trace_array *tr, | ^~~~~~~~~~~~~~~~~~~~~~ kernel/trace/trace.c:166:13: note: previous declaration of 'ftrace_trace_userstack' was here 166 | static void ftrace_trace_userstack(struct trace_array *tr, | ^~~~~~~~~~~~~~~~~~~~~~ kernel/trace/trace.c:3147:13: warning: 'ftrace_trace_userstack' defined but not used [-Wunused-function] 3147 | static void ftrace_trace_userstack(struct trace_array *tr, | ^~~~~~~~~~~~~~~~~~~~~~ kernel/trace/trace.c:1675:37: warning: 'tracing_max_lat_fops' defined but not used [-Wunused-const-variable=] 1675 | static const struct file_operations tracing_max_lat_fops; | ^~~~~~~~~~~~~~~~~~~~ vim +/ftrace_trace_userstack +166 kernel/trace/trace.c 9828413d4715d4e Steven Rostedt (Red Hat 2015-03-31 164) 9c5b9d3d65e4858 Masami Hiramatsu 2020-01-11 165 int tracing_set_tracer(struct trace_array *tr, const char *buf); bcee5278958802b Steven Rostedt (VMware 2020-12-04 @166) static void ftrace_trace_userstack(struct trace_array *tr, bcee5278958802b Steven Rostedt (VMware 2020-12-04 167) struct trace_buffer *buffer, afd5d9090ab105d Sebastian Andrzej Siewior 2020-12-16 168 unsigned int trace_ctx); b2821ae68b14480 Steven Rostedt 2009-02-02 169 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org