Re: [PATCH] mm: compaction: skip memory hole rapidly when isolating migratable pages

[Baolin Wang]

On 6/9/2023 10:48 PM, kernel test robot wrote:
> Hi Baolin,
>
> 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/Baolin-Wang/mm-compaction-skip-memory-hole-rapidly-when-isolating-migratable-pages/20230609-174659
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
> patch link:    https://lore.kernel.org/r/8cc668b77c8eb2fa78058b3d81386ebed9c5a9cd.1686294549.git.baolin.wang%40linux.alibaba.com
> patch subject: [PATCH] mm: compaction: skip memory hole rapidly when isolating migratable pages
> config: arm-randconfig-r025-20230609 (https://download.01.org/0day-ci/archive/20230609/202306092250.cp65gzkn-lkp@xxxxxxxxx/config)
> compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
> 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
>          # install arm cross compiling tool for clang build
>          # apt-get install binutils-arm-linux-gnueabi
>          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/8cc668b77c8eb2fa78058b3d81386ebed9c5a9cd.1686294549.git.baolin.wang@xxxxxxxxxxxxxxxxx
>          # save the config file
>          mkdir build_dir && cp config build_dir/.config
>          COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=arm olddefconfig
>          COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash
>
> 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/202306092250.cp65gzkn-lkp@xxxxxxxxx/
>
> All errors (new ones prefixed by >>):
>
> > > mm/compaction.c:235:27: error: call to undeclared function 'pfn_to_section_nr'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
>             unsigned long start_nr = pfn_to_section_nr(start_pfn);
>                                      ^
> > > mm/compaction.c:237:6: error: call to undeclared function 'online_section_nr'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
>             if (online_section_nr(start_nr))
>                 ^
> > > mm/compaction.c:240:19: error: call to undeclared function 'next_online_section_nr'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
>             next_online_nr = next_online_section_nr(start_nr);
>                              ^
> > > mm/compaction.c:242:10: error: call to undeclared function 'section_nr_to_pfn'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
>                     return section_nr_to_pfn(next_online_nr);
>                            ^
>     4 errors generated.

Thanks for report. I should provide a dummy function if CONFIG_SPARSEMEM 
is not selected.