Re: [PATCH v5 1/3] ring-buffer: Flush and stop persistent ring buffer on panic

On Fri, 27 Feb 2026 02:48:26 +0800
kernel test robot [off-list ref] wrote:

Hi Masami,

kernel test robot noticed the following build errors:

[auto build test ERROR on linus/master]
[also build test ERROR on v7.0-rc1 next-20260226]
[cannot apply to trace/for-next]
[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/Masami-Hiramatsu-Google/ring-buffer-Flush-and-stop-persistent-ring-buffer-on-panic/20260226-222418
base:   linus/master
patch link:    https://lore.kernel.org/r/177211311593.419230.2212568977306190482.stgit%40mhiramat.tok.corp.google.com
patch subject: [PATCH v5 1/3] ring-buffer: Flush and stop persistent ring buffer on panic
config: sparc-randconfig-001-20260227 (https://download.01.org/0day-ci/archive/20260227/202602270244.3JWhusi4-lkp@intel.com/config)
compiler: sparc64-linux-gcc (GCC) 11.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260227/202602270244.3JWhusi4-lkp@intel.com/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 [off-list ref]
| Closes: https://lore.kernel.org/oe-kbuild-all/202602270244.3JWhusi4-lkp@intel.com/ (local)

All errors (new ones prefixed by >>):

   kernel/trace/ring_buffer.c: In function 'rb_flush_buffer_cb':

quoted

quoted

kernel/trace/ring_buffer.c:2481:9: error: implicit declaration of function 'flush_cache_all'; did you mean 'flush_cache_page'? [-Werror=implicit-function-declaration]

    2481 |         flush_cache_all();
         |         ^~~~~~~~~~~~~~~
         |         flush_cache_page
   cc1: some warnings being treated as errors

I guess this is a miss of the sparc. Anyway, I will add asm/ring_buffer.h
to define a wrapper macro. At least I need to sync the cache on arm64 but
flush_cache_all() is a dummy on arm64. I would like to use dcache_clear_pop()
instead.

Thanks,

vim +2481 kernel/trace/ring_buffer.c

  2475	
  2476	static int rb_flush_buffer_cb(struct notifier_block *nb, unsigned long event, void *data)
  2477	{
  2478		struct trace_buffer *buffer = container_of(nb, struct trace_buffer, flush_nb);
  2479	
  2480		ring_buffer_record_off(buffer);

quoted

2481		flush_cache_all();

  2482		return NOTIFY_DONE;
  2483	}
  2484	

-- 
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https://github.com/intel/lkp-tests/wiki

-- 
Masami Hiramatsu (Google) [off-list ref]