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

From: kernel test robot

Date: Thu Feb 26 2026 - 13:33:10 EST


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: sparc64-defconfig (https://download.01.org/0day-ci/archive/20260227/202602270132.zddhkLDS-lkp@xxxxxxxxx/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260227/202602270132.zddhkLDS-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/202602270132.zddhkLDS-lkp@xxxxxxxxx/

All errors (new ones prefixed by >>):

>> kernel/trace/ring_buffer.c:2481:2: error: call to undeclared function 'flush_cache_all'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
2481 | flush_cache_all();
| ^
kernel/trace/ring_buffer.c:2481:2: note: did you mean 'flush_dcache_page'?
arch/sparc/include/asm/cacheflush_64.h:51:20: note: 'flush_dcache_page' declared here
51 | static inline void flush_dcache_page(struct page *page)
| ^
1 error generated.


vim +/flush_cache_all +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);
> 2481 flush_cache_all();
2482 return NOTIFY_DONE;
2483 }
2484

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