Hi Daniel,

kernel test robot noticed the following build warnings:

[auto build test WARNING on linus/master]
[also build test WARNING on v6.4-rc3 next-20230523]
[cannot apply to rostedt-trace/for-next rostedt-trace/for-next-urgent]
[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#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Daniel-Bristot-de-Oliveira/tracing-osnoise-Switch-from-PF_NO_SETAFFINITY-to-migrate_disable/20230524-012512
base:   linus/master
patch link:    https://lore.kernel.org/r/a7b2c215c763e95a56fa1258743332b570c81c9d.1684860626.git.bristot%40kernel.org
patch subject: [PATCH V2 3/3] tracing/timerlat: Add user-space interface
config: loongarch-allyesconfig
compiler: loongarch64-linux-gcc (GCC) 12.1.0
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
        # https://github.com/intel-lab-lkp/linux/commit/89216b54eaf490480bc1929f5780f95a688a91bb
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Daniel-Bristot-de-Oliveira/tracing-osnoise-Switch-from-PF_NO_SETAFFINITY-to-migrate_disable/20230524-012512
        git checkout 89216b54eaf490480bc1929f5780f95a688a91bb
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=loongarch olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=loongarch SHELL=/bin/bash kernel/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202305240459.z43SP4XU-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> kernel/trace/trace_osnoise.c:2645:5: warning: no previous prototype for 'osnoise_create_cpu_timerlat_fd' [-Wmissing-prototypes]
    2645 | int osnoise_create_cpu_timerlat_fd(struct dentry *top_dir)
         |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/osnoise_create_cpu_timerlat_fd +2645 kernel/trace/trace_osnoise.c

  2644	
> 2645	int osnoise_create_cpu_timerlat_fd(struct dentry *top_dir)
  2646	{
  2647		struct dentry *timerlat_fd;
  2648		struct dentry *per_cpu;
  2649		struct dentry *cpu_dir;
  2650		char cpu_str[30]; /* see trace.c: tracing_init_tracefs_percpu() */
  2651		long cpu;
  2652	
  2653		/*
  2654		 * Why not using tracing instance per_cpu/ dir?
  2655		 *
  2656		 * Because osnoise/timerlat have a single workload, having
  2657		 * multiple files like these are wast of memory.
  2658		 */
  2659		per_cpu = tracefs_create_dir("per_cpu", top_dir);
  2660		if (!per_cpu)
  2661			return -ENOMEM;
  2662	
  2663		for_each_possible_cpu(cpu) {
  2664			snprintf(cpu_str, 30, "cpu%ld", cpu);
  2665			cpu_dir = tracefs_create_dir(cpu_str, per_cpu);
  2666			if (!cpu_dir)
  2667				goto out_clean;
  2668	
  2669			timerlat_fd = trace_create_file("timerlat_fd", TRACE_MODE_READ,
  2670							cpu_dir, NULL, &timerlat_fd_fops);
  2671			if (!timerlat_fd)
  2672				goto out_clean;
  2673	
  2674			/* Record the CPU */
  2675			d_inode(timerlat_fd)->i_cdev = (void *)(cpu);
  2676		}
  2677	
  2678		return 0;
  2679	
  2680	out_clean:
  2681		tracefs_remove(per_cpu);
  2682		return -ENOMEM;
  2683	}
  2684	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki