Re: [PATCH] mm/memcg: remove return value of mem_cgroup_scan_tasks()

["zhangpeng (AS)" <zhangpeng362@huawei.com>]

On 2023/6/16 13:13, kernel test robot wrote:

> Hi Peng,
>
> kernel test robot noticed the following build errors:
>
> [auto build test ERROR on akpm-mm/mm-everything]
>
> url:    https://github.com/intel-lab-lkp/linux/commits/Peng-Zhang/mm-memcg-remove-return-value-of-mem_cgroup_scan_tasks/20230616-102145
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
> patch link:    https://lore.kernel.org/r/20230616021955.872413-1-zhangpeng362%40huawei.com
> patch subject: [PATCH] mm/memcg: remove return value of mem_cgroup_scan_tasks()
> config: x86_64-randconfig-r005-20230616 (https://download.01.org/0day-ci/archive/20230616/202306161306.9YKbncNT-lkp@intel.com/config)
> compiler: clang version 15.0.7 (https://github.com/llvm/llvm-project.git 8dfdcc7b7bf66834a761bd8de445840ef68e4d1a)
> reproduce (this is a W=1 build):
>          mkdir -p ~/bin
>          wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>          chmod +x ~/bin/make.cross
>          git remote add akpm-mm https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git
>          git fetch akpm-mm mm-everything
>          git checkout akpm-mm/mm-everything
>          b4 shazam https://lore.kernel.org/r/20230616021955.872413-1-zhangpeng362@huawei.com
>          # save the config file
>          mkdir build_dir && cp config build_dir/.config
>          COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=x86_64 olddefconfig
>          COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=x86_64 prepare
>
> 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/202306161306.9YKbncNT-lkp@intel.com/
>
> All errors (new ones prefixed by >>):
>
>     In file included from arch/x86/kernel/asm-offsets.c:14:
>     In file included from include/linux/suspend.h:5:
>     In file included from include/linux/swap.h:9:
>>> include/linux/memcontrol.h:1370:2: error: void function 'mem_cgroup_scan_tasks' should not return a value [-Wreturn-type]
>             return 0;

Thanks for reporting. I'll drop this line.

>             ^      ~
>     1 error generated.
>     make[2]: *** [scripts/Makefile.build:114: arch/x86/kernel/asm-offsets.s] Error 1 shuffle=3878817758
>     make[2]: Target 'prepare' not remade because of errors.
>     make[1]: *** [Makefile:1287: prepare0] Error 2 shuffle=3878817758
>     make[1]: Target 'prepare' not remade because of errors.
>     make: *** [Makefile:226: __sub-make] Error 2 shuffle=3878817758
>     make: Target 'prepare' not remade because of errors.
>
>
> vim +/mem_cgroup_scan_tasks +1370 include/linux/memcontrol.h
>
> 5660048ccac873 Johannes Weiner  2012-01-12  1366
> 5044a2e0ddbf82 ZhangPeng        2023-06-16  1367  static inline void mem_cgroup_scan_tasks(struct mem_cgroup *memcg,
> 7c5f64f84483bd Vladimir Davydov 2016-10-07  1368  		int (*fn)(struct task_struct *, void *), void *arg)
> 7c5f64f84483bd Vladimir Davydov 2016-10-07  1369  {
> 7c5f64f84483bd Vladimir Davydov 2016-10-07 @1370  	return 0;
> 7c5f64f84483bd Vladimir Davydov 2016-10-07  1371  }
> 7c5f64f84483bd Vladimir Davydov 2016-10-07  1372
>