On Fri, Jul 05, 2024 at 10:43:41PM +0800, kernel test robot wrote: > kernel test robot noticed the following build warnings: > > [auto build test WARNING on akpm-mm/mm-everything] > > url: https://github.com/intel-lab-lkp/linux/commits/alexs-kernel-org/mm-zsmalloc-add-zpdesc-memory-descriptor-for-zswap-zpool/20240703-182314 > base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything > patch link: https://lore.kernel.org/r/20240703040613.681396-18-alexs%40kernel.org > patch subject: [PATCH v2 17/20] mm/zsmalloc: convert get/set_first_obj_offset() to take zpdesc > config: i386-randconfig-002-20240705 (https://download.01.org/0day-ci/archive/20240705/202407052102.qbT7nLMK-lkp@xxxxxxxxx/config) > compiler: clang version 18.1.5 (https://github.com/llvm/llvm-project 617a15a9eac96088ae5e9134248d8236e34b91b1) > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240705/202407052102.qbT7nLMK-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/202407052102.qbT7nLMK-lkp@xxxxxxxxx/ > > All warnings (new ones prefixed by >>): > > >> mm/zsmalloc.c:471:12: warning: function 'is_first_zpdesc' is not needed and will not be emitted [-Wunneeded-internal-declaration] > 471 | static int is_first_zpdesc(struct zpdesc *zpdesc) > | ^~~~~~~~~~~~~~~ > 1 warning generated. I am not sure why the robot thinks that this change introduced this warning, I think it has been present since patch 2 of this series. The warning occurs when CONFIG_DEBUG_VM is disabled because is_first_zpdesc() is used with VM_BUG_ON_PAGE, which ultimately evaluates to BUILD_BUG_ON_INVALID() / sizeof(), so is_first_zpdesc() is only used in a compile time context for this configuration. Perhaps this can just be marked as __maybe_unused? Cheers, Nathan
