Re: [PATCH 2/2] mm/huge_memory: do not overkill when splitting huge_zero_page

[Yu Xu <xuyu@linux.alibaba.com>]

Thanks!

Sorry for that I tested only with CONFIG_DEBUG_VM enabled. This issue is
triggered when CONFIG_DEBUG_VM is disabled.

PATCH 2/2 has been resend.

On 4/27/22 5:01 PM, kernel test robot wrote:
> Hi Xu,
> 
> Thank you for the patch! Yet something to improve:
> 
> [auto build test ERROR on hnaz-mm/master]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Xu-Yu/mm-memory-failure-rework-fix-on-huge_zero_page-splitting/20220427-141253
> base:   https://github.com/hnaz/linux-mm master
> config: s390-randconfig-r044-20220425 (https://download.01.org/0day-ci/archive/20220427/202204271636.UqHlxRwk-lkp@intel.com/config)
> compiler: s390-linux-gcc (GCC) 11.3.0
> reproduce (this is a W=1 build):
>          wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>          chmod +x ~/bin/make.cross
>          # https://github.com/intel-lab-lkp/linux/commit/988ec6e274e00e5706be7590a4a39427fbe856b1
>          git remote add linux-review https://github.com/intel-lab-lkp/linux
>          git fetch --no-tags linux-review Xu-Yu/mm-memory-failure-rework-fix-on-huge_zero_page-splitting/20220427-141253
>          git checkout 988ec6e274e00e5706be7590a4a39427fbe856b1
>          # save the config file
>          mkdir build_dir && cp config build_dir/.config
>          COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All errors (new ones prefixed by >>):
> 
>     In file included from include/linux/bits.h:22,
>                      from include/linux/ratelimit_types.h:5,
>                      from include/linux/printk.h:10,
>                      from include/asm-generic/bug.h:22,
>                      from arch/s390/include/asm/bug.h:68,
>                      from include/linux/bug.h:5,
>                      from include/linux/mmdebug.h:5,
>                      from include/linux/mm.h:6,
>                      from mm/huge_memory.c:8:
>     mm/huge_memory.c: In function 'split_huge_page_to_list':
>>> include/linux/build_bug.h:30:33: error: void value not ignored as it ought to be
>        30 | #define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e))))
>           |                                 ^
>     include/linux/mmdebug.h:81:43: note: in expansion of macro 'BUILD_BUG_ON_INVALID'
>        81 | #define VM_WARN_ON_ONCE_PAGE(cond, page)  BUILD_BUG_ON_INVALID(cond)
>           |                                           ^~~~~~~~~~~~~~~~~~~~
>     mm/huge_memory.c:2553:13: note: in expansion of macro 'VM_WARN_ON_ONCE_PAGE'
>      2553 |         if (VM_WARN_ON_ONCE_PAGE(is_huge_zero_page(head), head))
>           |             ^~~~~~~~~~~~~~~~~~~~
> 
> 
> vim +30 include/linux/build_bug.h
> 
> 527edbc18a70e74 Masahiro Yamada 2019-01-03  18
> 527edbc18a70e74 Masahiro Yamada 2019-01-03  19  /* Force a compilation error if a constant expression is not a power of 2 */
> 527edbc18a70e74 Masahiro Yamada 2019-01-03  20  #define __BUILD_BUG_ON_NOT_POWER_OF_2(n)	\
> 527edbc18a70e74 Masahiro Yamada 2019-01-03  21  	BUILD_BUG_ON(((n) & ((n) - 1)) != 0)
> 527edbc18a70e74 Masahiro Yamada 2019-01-03  22  #define BUILD_BUG_ON_NOT_POWER_OF_2(n)			\
> 527edbc18a70e74 Masahiro Yamada 2019-01-03  23  	BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
> bc6245e5efd70c4 Ian Abbott      2017-07-10  24
> bc6245e5efd70c4 Ian Abbott      2017-07-10  25  /*
> bc6245e5efd70c4 Ian Abbott      2017-07-10  26   * BUILD_BUG_ON_INVALID() permits the compiler to check the validity of the
> bc6245e5efd70c4 Ian Abbott      2017-07-10  27   * expression but avoids the generation of any code, even if that expression
> bc6245e5efd70c4 Ian Abbott      2017-07-10  28   * has side-effects.
> bc6245e5efd70c4 Ian Abbott      2017-07-10  29   */
> bc6245e5efd70c4 Ian Abbott      2017-07-10 @30  #define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e))))
> bc6245e5efd70c4 Ian Abbott      2017-07-10  31
> 

-- 
Thanks,
Yu