Re: [PATCH v14 4/6] tracing: Allow user-space mapping of the ring-buffer

[kernel test robot]

Hi Vincent,

kernel test robot noticed the following build warnings:

[auto build test WARNING on e2412e51fdea837b50ce31fea8e5dfc885237f3a]

url:    https://github.com/intel-lab-lkp/linux/commits/Vincent-Donnefort/ring-buffer-Zero-ring-buffer-sub-buffers/20240206-004413
base:   e2412e51fdea837b50ce31fea8e5dfc885237f3a
patch link:    https://lore.kernel.org/r/20240205163410.2296552-5-vdonnefort%40google.com
patch subject: [PATCH v14 4/6] tracing: Allow user-space mapping of the ring-buffer
config: arc-defconfig (https://download.01.org/0day-ci/archive/20240206/202402061809.T2cv9J8W-lkp@xxxxxxxxx/config)
compiler: arc-elf-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240206/202402061809.T2cv9J8W-lkp@xxxxxxxxx/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202402061809.T2cv9J8W-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

   kernel/trace/trace.c: In function 'tracing_buffers_mmap_close':
>> kernel/trace/trace.c:8722:29: warning: unused variable 'tr' [-Wunused-variable]
    8722 |         struct trace_array *tr = iter->tr;
         |                             ^~
   kernel/trace/trace.c: In function 'tracing_buffers_mmap':
   kernel/trace/trace.c:8752:29: warning: unused variable 'tr' [-Wunused-variable]
    8752 |         struct trace_array *tr = iter->tr;
         |                             ^~


vim +/tr +8722 kernel/trace/trace.c

  8717	
  8718	static void tracing_buffers_mmap_close(struct vm_area_struct *vma)
  8719	{
  8720		struct ftrace_buffer_info *info = vma->vm_file->private_data;
  8721		struct trace_iterator *iter = &info->iter;
> 8722		struct trace_array *tr = iter->tr;
  8723	
  8724		ring_buffer_unmap(iter->array_buffer->buffer, iter->cpu_file);
  8725	

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