Re: [akpm-mm:mm-unstable 69/88] arch/powerpc/mm/init_64.c:390:6: error: redefinition of 'register_page_bootmem_memmap'

[Frank van der Linden <fvdl@google.com>]

On Fri, Jan 31, 2025 at 2:16 AM kernel test robot <lkp@intel.com> wrote:
>
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-unstable
> head:   f5604ad70091eabe663ea7106ced99449d653320
> commit: 2acfe4c72e4e3a50a685652d89c927335b90c947 [69/88] mm/bootmem_info: export register_page_bootmem_memmap
> config: powerpc64-randconfig-003-20250131 (https://download.01.org/0day-ci/archive/20250131/202501311826.hU85Yygn-lkp@intel.com/config)
> compiler: clang version 15.0.7 (https://github.com/llvm/llvm-project 8dfdcc7b7bf66834a761bd8de445840ef68e4d1a)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250131/202501311826.hU85Yygn-lkp@intel.com/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@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202501311826.hU85Yygn-lkp@intel.com/
>
> All errors (new ones prefixed by >>):
>
> >> arch/powerpc/mm/init_64.c:390:6: error: redefinition of 'register_page_bootmem_memmap'
>    void register_page_bootmem_memmap(unsigned long section_nr,
>         ^
>    include/linux/bootmem_info.h:63:20: note: previous definition is here
>    static inline void register_page_bootmem_memmap(unsigned long section_nr,
>                       ^
>    1 error generated.
>
>
> vim +/register_page_bootmem_memmap +390 arch/powerpc/mm/init_64.c
>
> 368a0590d954a6 Aneesh Kumar K.V       2023-07-25  388
> 71b0bfe4f1608d Li Zhong               2014-06-11  389  #endif
> f7e3334a6bcb42 Nathan Fontenot        2013-09-27 @390  void register_page_bootmem_memmap(unsigned long section_nr,
> f7e3334a6bcb42 Nathan Fontenot        2013-09-27  391                             struct page *start_page, unsigned long size)
> f7e3334a6bcb42 Nathan Fontenot        2013-09-27  392  {
> f7e3334a6bcb42 Nathan Fontenot        2013-09-27  393  }
> cd3db0c4ca3d23 Benjamin Herrenschmidt 2010-07-06  394
>
> :::::: The code at line 390 was first introduced by commit
> :::::: f7e3334a6bcb42e7295a9bd9cb36ca4e6e4e66b4 powerpc: Fix memory hotplug with sparse vmemmap
>
> :::::: TO: Nathan Fontenot <nfont@linux.vnet.ibm.com>
> :::::: CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki

Looks like my patch "mm/bootmem_info: export
register_page_bootmem_memmap" exposed a (small) issue in the powerpc
code: the (empty) definition of register_page_boot_memmap code is not
wrapped in #ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE, like on x86.

That causes this compilation failure for this config which has
SPARSE_VMEMMAP enabled, but MEMORY_HOTREMOVE disabled (so no
HAVE_BOOTMEM_INFO_NODE).

I'll add a fix to wrap the definition in #ifdef
CONFIG_HAVE_BOOTMEM_INFO_NODE, like on x86, in. the aforementioned
patch in my series. I'll spin up a v3 with it, since there were some
other things that needed changing (checkpatch SPDX warning, and
missing debugfs change documentation).

- Frank