On Wed, Jun 11, 2025 at 4:08 PM Masami Hiramatsu [off-list ref] wrote:

On Wed, 11 Jun 2025 13:15:40 +0800
Jason Xing [off-list ref] wrote:

quoted

On Wed, Jun 11, 2025 at 9:42 AM kernel test robot [off-list ref] wrote:

quoted

Hi Jason,

kernel test robot noticed the following build warnings:

[auto build test WARNING on axboe-block/for-next]
[also build test WARNING on drm-i915/for-linux-next drm-i915/for-linux-next-fixes akpm-mm/mm-everything linus/master v6.16-rc1 next-20250610]
[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/Jason-Xing/relayfs-abolish-prev_padding/20250610-085150
base:   https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git for-next
patch link:    https://lore.kernel.org/r/20250610004844.66688-5-kerneljasonxing%40gmail.com
patch subject: [PATCH v4 4/5] blktrace: use rbuf->stats.full as a drop indicator in relayfs
config: arc-randconfig-001-20250610
compiler: arc-linux-gcc (GCC) 12.4.0
reproduce (this is a W=1 build):

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 [off-list ref]
| Closes: https://lore.kernel.org/oe-kbuild-all/202506102340.uo7QDaVk-lkp@intel.com/ (local)

All warnings (new ones prefixed by >>):

   kernel/trace/blktrace.c: In function 'blk_dropped_read':

quoted

quoted

kernel/trace/blktrace.c:421:39: warning: format '%lu' expects argument of type 'long unsigned int', but argument 4 has type 'size_t' {aka 'unsigned int'} [-Wformat=]

     421 |         snprintf(buf, sizeof(buf), "%lu\n", dropped);
         |                                     ~~^     ~~~~~~~
         |                                       |     |
         |                                       |     size_t {aka unsigned int}
         |                                       long unsigned int
         |                                     %u

Well, I suppose I will fix it in the re-spin after receiving more
comments so that I don't need to quickly respond to this minor issue.

Please update the patch and send series with my reviewed-by on 1/5.

Sure, thanks for the review.

BTW, size_t should use %zu.
Please check Documentation/core-api/printk-formats.rst

Thanks for the pointer :)

Thanks,
Jason

Thank you,

quoted

Thanks,
Jason

quoted

vim +421 kernel/trace/blktrace.c

   413
   414  static ssize_t blk_dropped_read(struct file *filp, char __user *buffer,
   415                                  size_t count, loff_t *ppos)
   416  {
   417          struct blk_trace *bt = filp->private_data;
   418          size_t dropped = relay_stats(bt->rchan, RELAY_STATS_BUF_FULL);
   419          char buf[16];
   420
 > 421          snprintf(buf, sizeof(buf), "%lu\n", dropped);
   422
   423          return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf));
   424  }
   425

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Masami Hiramatsu (Google) [off-list ref]