Re: [PATCH 3/3] mutex: Remove the list_head from struct mutex

[kernel test robot]

Hi Matthew,

kernel test robot noticed the following build warnings:

[auto build test WARNING on tip/locking/core]
[also build test WARNING on rafael-pm/linux-next rafael-pm/bleeding-edge linus/master v7.0-rc2 next-20260306]
[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/Matthew-Wilcox-Oracle/rwsem-Remove-the-list_head-from-struct-rw_semaphore/20260306-085403
base:   tip/locking/core
patch link:    https://lore.kernel.org/r/20260305195545.3707590-4-willy%40infradead.org
patch subject: [PATCH 3/3] mutex: Remove the list_head from struct mutex
config: powerpc64-randconfig-r061-20260307 (https://download.01.org/0day-ci/archive/20260307/202603070817.Ce5296iz-lkp@xxxxxxxxx/config)
compiler: powerpc64-linux-gcc (GCC) 12.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260307/202603070817.Ce5296iz-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/202603070817.Ce5296iz-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

   In file included from include/linux/seqlock.h:20,
                    from include/linux/mmzone.h:17,
                    from include/linux/gfp.h:7,
                    from include/linux/umh.h:4,
                    from include/linux/kmod.h:9,
                    from include/linux/module.h:18,
                    from drivers/char/nvram.c:34:
>> drivers/char/nvram.c:56:21: warning: 'nvram_mutex' defined but not used [-Wunused-variable]
      56 | static DEFINE_MUTEX(nvram_mutex);
         |                     ^~~~~~~~~~~
   include/linux/mutex.h:87:22: note: in definition of macro 'DEFINE_MUTEX'
      87 |         struct mutex mutexname = __MUTEX_INITIALIZER(mutexname)
         |                      ^~~~~~~~~


vim +/nvram_mutex +56 drivers/char/nvram.c

^1da177e4c3f41 Linus Torvalds 2005-04-16  55  
613655fa39ff69 Arnd Bergmann  2010-06-02 @56  static DEFINE_MUTEX(nvram_mutex);
^1da177e4c3f41 Linus Torvalds 2005-04-16  57  static DEFINE_SPINLOCK(nvram_state_lock);
^1da177e4c3f41 Linus Torvalds 2005-04-16  58  static int nvram_open_cnt;	/* #times opened */
^1da177e4c3f41 Linus Torvalds 2005-04-16  59  static int nvram_open_mode;	/* special open modes */
d5bbb5021ce8d9 Finn Thain     2019-01-15  60  static ssize_t nvram_size;
^1da177e4c3f41 Linus Torvalds 2005-04-16  61  #define NVRAM_WRITE		1 /* opened for writing (exclusive) */
^1da177e4c3f41 Linus Torvalds 2005-04-16  62  #define NVRAM_EXCL		2 /* opened with O_EXCL */
^1da177e4c3f41 Linus Torvalds 2005-04-16  63  

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