Re: [RFC 2/2] mm: page_alloc: per-cpu pageblock buddy allocator

[kernel test robot <lkp@intel.com>]

Hi Johannes,

[This is a private test report for your RFC patch.]
kernel test robot noticed the following build errors:

[auto build test ERROR on rppt-memblock/for-next]
[also build test ERROR on rppt-memblock/fixes linus/master v7.0-rc7 next-20260407]
[cannot apply to akpm-mm/mm-everything]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Johannes-Weiner/mm-page_alloc-replace-pageblock_flags-bitmap-with-struct-pageblock_data/20260407-193348
base:   https://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock.git for-next
patch link:    https://lore.kernel.org/r/20260403194526.477775-3-hannes%40cmpxchg.org
patch subject: [RFC 2/2] mm: page_alloc: per-cpu pageblock buddy allocator
config: i386-allnoconfig-bpf (https://download.01.org/0day-ci/archive/20260408/202604080453.g3eQBKxN-lkp@intel.com/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260408/202604080453.g3eQBKxN-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/r/202604080453.g3eQBKxN-lkp@intel.com/

All error/warnings (new ones prefixed by >>):

   In file included from kernel/fork.c:118:
   kernel/../mm/internal.h: In function 'pfn_to_pageblock':
>> kernel/../mm/internal.h:803:37: error: invalid use of undefined type 'struct pageblock_data'
     803 |         return &zone->pageblock_data[idx];
         |                                     ^
--
   In file included from mm/filemap.c:54:
   mm/internal.h: In function 'pfn_to_pageblock':
>> mm/internal.h:803:37: error: invalid use of undefined type 'struct pageblock_data'
     803 |         return &zone->pageblock_data[idx];
         |                                     ^
--
   In file included from mm/mm_init.c:35:
   mm/internal.h: In function 'pfn_to_pageblock':
>> mm/internal.h:803:37: error: invalid use of undefined type 'struct pageblock_data'
     803 |         return &zone->pageblock_data[idx];
         |                                     ^
   mm/mm_init.c: In function 'usemap_size':
>> mm/mm_init.c:1456:39: error: invalid application of 'sizeof' to incomplete type 'struct pageblock_data'
    1456 |         return nr_pageblocks * sizeof(struct pageblock_data);
         |                                       ^~~~~~
>> mm/mm_init.c:1457:1: warning: control reaches end of non-void function [-Wreturn-type]
    1457 | }
         | ^
--
   In file included from mm/page_alloc.c:58:
   mm/internal.h: In function 'pfn_to_pageblock':
>> mm/internal.h:803:37: error: invalid use of undefined type 'struct pageblock_data'
     803 |         return &zone->pageblock_data[idx];
         |                                     ^
   mm/page_alloc.c: In function 'get_pfnblock_flags_word':
>> mm/page_alloc.c:363:44: error: invalid use of undefined type 'struct pageblock_data'
     363 |         return &pfn_to_pageblock(page, pfn)->flags;
         |                                            ^~
>> mm/page_alloc.c:364:1: warning: control reaches end of non-void function [-Wreturn-type]
     364 | }
         | ^
--
   In file included from fs/exec.c:82:
   fs/../mm/internal.h: In function 'pfn_to_pageblock':
>> fs/../mm/internal.h:803:37: error: invalid use of undefined type 'struct pageblock_data'
     803 |         return &zone->pageblock_data[idx];
         |                                     ^
--
   In file included from lib/vsprintf.c:51:
   lib/../mm/internal.h: In function 'pfn_to_pageblock':
>> lib/../mm/internal.h:803:37: error: invalid use of undefined type 'struct pageblock_data'
     803 |         return &zone->pageblock_data[idx];
         |                                     ^


vim +803 kernel/../mm/internal.h

8170ac4700d26f Zi Yan          2022-04-28  789  
d88d3563065850 Johannes Weiner 2026-04-03  790  static inline struct pageblock_data *pfn_to_pageblock(const struct page *page,
d88d3563065850 Johannes Weiner 2026-04-03  791  						      unsigned long pfn)
d88d3563065850 Johannes Weiner 2026-04-03  792  {
d88d3563065850 Johannes Weiner 2026-04-03  793  #ifdef CONFIG_SPARSEMEM
d88d3563065850 Johannes Weiner 2026-04-03  794  	struct mem_section *ms = __pfn_to_section(pfn);
d88d3563065850 Johannes Weiner 2026-04-03  795  	unsigned long idx = (pfn & (PAGES_PER_SECTION - 1)) >> pageblock_order;
d88d3563065850 Johannes Weiner 2026-04-03  796  
d88d3563065850 Johannes Weiner 2026-04-03  797  	return &section_to_usemap(ms)[idx];
d88d3563065850 Johannes Weiner 2026-04-03  798  #else
d88d3563065850 Johannes Weiner 2026-04-03  799  	struct zone *zone = page_zone(page);
d88d3563065850 Johannes Weiner 2026-04-03  800  	unsigned long idx;
d88d3563065850 Johannes Weiner 2026-04-03  801  
d88d3563065850 Johannes Weiner 2026-04-03  802  	idx = (pfn - pageblock_start_pfn(zone->zone_start_pfn)) >> pageblock_order;
d88d3563065850 Johannes Weiner 2026-04-03 @803  	return &zone->pageblock_data[idx];
d88d3563065850 Johannes Weiner 2026-04-03  804  #endif
d88d3563065850 Johannes Weiner 2026-04-03  805  }
d88d3563065850 Johannes Weiner 2026-04-03  806  

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