Re: [PATCH V2 3/5] sys_info: add help to translate sys_info string to bitmap

[Feng Tang <feng.tang@linux.alibaba.com>]

On Mon, Jun 16, 2025 at 12:25:29PM +0800, kernel test robot wrote:
> Hi Feng,
> 
> kernel test robot noticed the following build warnings:
> 
> [auto build test WARNING on akpm-mm/mm-nonmm-unstable]
> [also build test WARNING on akpm-mm/mm-everything linus/master v6.16-rc2 next-20250613]
> [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/Feng-Tang/panic-clean-up-code-for-console-replay/20250616-091042
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-nonmm-unstable
> patch link:    https://lore.kernel.org/r/20250616010840.38258-4-feng.tang%40linux.alibaba.com
> patch subject: [PATCH V2 3/5] sys_info: add help to translate sys_info string to bitmap
> config: x86_64-buildonly-randconfig-001-20250616 (https://download.01.org/0day-ci/archive/20250616/202506161234.wRZSzo5v-lkp@intel.com/config)
> compiler: clang version 20.1.2 (https://github.com/llvm/llvm-project 58df0ef89dd64126512e4ee27b4ac3fd8ddf6247)
> rustc: rustc 1.78.0 (9b00956e5 2024-04-29)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250616/202506161234.wRZSzo5v-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 <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202506161234.wRZSzo5v-lkp@intel.com/
> 
> All warnings (new ones prefixed by >>):
> 
> >> lib/sys_info.c:13:19: warning: unused variable 'sys_info_avail' [-Wunused-const-variable]
>       13 | static const char sys_info_avail[] = "tasks,mem,timer,lock,ftrace,all_bt,blocked_tasks";
>          |                   ^~~~~~~~~~~~~~
>    1 warning generated.

Thanks for the reporting! This is related with CONFIG_SYSCTL=n, and
should be fixed by below patch:

---
diff --git a/lib/sys_info.c b/lib/sys_info.c
index 9693542435ba..ca289b4871b4 100644
--- a/lib/sys_info.c
+++ b/lib/sys_info.c
@@ -10,8 +10,6 @@ struct sys_info_name {
 	const char *name;
 };
 
-static const char sys_info_avail[] = "tasks,mem,timer,lock,ftrace,all_bt,blocked_tasks";
-
 static const struct sys_info_name  si_names[] = {
 	{ SYS_SHOW_TASK_INFO,	"tasks" },
 	{ SYS_SHOW_MEM_INFO,	"mem" },
@@ -43,6 +41,8 @@ unsigned long sys_info_parse_param(char *str)
 }
 
 #ifdef CONFIG_SYSCTL
+static const char sys_info_avail[] = "tasks,mem,timer,lock,ftrace,all_bt,blocked_tasks";
+
 int sysctl_sys_info_handler(const struct ctl_table *ro_table, int write,
 					  void *buffer, size_t *lenp,
 					  loff_t *ppos)