Re: [v1 6/6] mm: hugetlb: Skip initialization of struct pages freed later by HVO

[kernel test robot]

Hi Usama,

kernel test robot noticed the following build warnings:

[auto build test WARNING on akpm-mm/mm-everything]

url:    https://github.com/intel-lab-lkp/linux/commits/Usama-Arif/mm-hugetlb-Skip-prep-of-tail-pages-when-HVO-is-enabled/20230728-044839
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20230727204624.1942372-7-usama.arif%40bytedance.com
patch subject: [v1 6/6] mm: hugetlb: Skip initialization of struct pages freed later by HVO
config: i386-debian-10.3 (https://download.01.org/0day-ci/archive/20230729/202307290029.Kr5EEBeY-lkp@xxxxxxxxx/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce: (https://download.01.org/0day-ci/archive/20230729/202307290029.Kr5EEBeY-lkp@xxxxxxxxx/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@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202307290029.Kr5EEBeY-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

   In file included from mm/hugetlb.c:49:
   mm/hugetlb_vmemmap.h:56:6: warning: no previous prototype for 'vmemmap_should_optimize' [-Wmissing-prototypes]
      56 | bool vmemmap_should_optimize(const struct hstate *h, const struct page *head)
         |      ^~~~~~~~~~~~~~~~~~~~~~~
   mm/hugetlb.c: In function '__alloc_bootmem_huge_page':
   mm/hugetlb.c:3198:17: error: 'HUGETLB_VMEMMAP_RESERVE_SIZE' undeclared (first use in this function)
    3198 |                 HUGETLB_VMEMMAP_RESERVE_SIZE * sizeof(struct page);
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
   mm/hugetlb.c:3198:17: note: each undeclared identifier is reported only once for each function it appears in
>> mm/hugetlb.c:3210:42: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
    3210 |                                 (void *)((phys_addr_t) m + hugetlb_vmemmap_reserve_size));
         |                                          ^
>> mm/hugetlb.c:3210:33: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
    3210 |                                 (void *)((phys_addr_t) m + hugetlb_vmemmap_reserve_size));
         |                                 ^
   mm/hugetlb.c:3233:42: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
    3233 |                                 (void *)((phys_addr_t) m + hugetlb_vmemmap_reserve_size));
         |                                          ^
   mm/hugetlb.c:3233:33: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
    3233 |                                 (void *)((phys_addr_t) m + hugetlb_vmemmap_reserve_size));
         |                                 ^


vim +3210 mm/hugetlb.c

  3190	
  3191	int alloc_bootmem_huge_page(struct hstate *h, int nid)
  3192		__attribute__ ((weak, alias("__alloc_bootmem_huge_page")));
  3193	int __alloc_bootmem_huge_page(struct hstate *h, int nid)
  3194	{
  3195		struct huge_bootmem_page *m = NULL; /* initialize for clang */
  3196		int nr_nodes, node;
  3197		phys_addr_t hugetlb_vmemmap_reserve_size =
  3198			HUGETLB_VMEMMAP_RESERVE_SIZE * sizeof(struct page);
  3199		phys_addr_t noinit_base;
  3200	
  3201		/* do node specific alloc */
  3202		if (nid != NUMA_NO_NODE) {
  3203			m = memblock_alloc_try_nid_raw(huge_page_size(h), huge_page_size(h),
  3204					0, MEMBLOCK_ALLOC_ACCESSIBLE, nid);
  3205			if (!m)
  3206				return 0;
  3207	
  3208			if (vmemmap_optimize_enabled && hugetlb_vmemmap_optimizable(h)) {
  3209				noinit_base = virt_to_phys(
> 3210					(void *)((phys_addr_t) m + hugetlb_vmemmap_reserve_size));
  3211				memblock_rsrv_mark_noinit(
  3212					noinit_base,
  3213					huge_page_size(h) - hugetlb_vmemmap_reserve_size);
  3214			}
  3215	
  3216			goto found;
  3217		}
  3218		/* allocate from next node when distributing huge pages */
  3219		for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) {
  3220			m = memblock_alloc_try_nid_raw(
  3221					huge_page_size(h), huge_page_size(h),
  3222					0, MEMBLOCK_ALLOC_ACCESSIBLE, node);
  3223			/*
  3224			 * Use the beginning of the huge page to store the
  3225			 * huge_bootmem_page struct (until gather_bootmem
  3226			 * puts them into the mem_map).
  3227			 */
  3228			if (!m)
  3229				return 0;
  3230	
  3231			if (vmemmap_optimize_enabled && hugetlb_vmemmap_optimizable(h)) {
  3232				noinit_base = virt_to_phys(
  3233					(void *)((phys_addr_t) m + hugetlb_vmemmap_reserve_size));
  3234				memblock_rsrv_mark_noinit(
  3235					noinit_base,
  3236					huge_page_size(h) - hugetlb_vmemmap_reserve_size);
  3237			}
  3238	
  3239			goto found;
  3240		}
  3241	
  3242	found:
  3243		/* Put them into a private list first because mem_map is not up yet */
  3244		INIT_LIST_HEAD(&m->list);
  3245		list_add(&m->list, &huge_boot_pages);
  3246		m->hstate = h;
  3247		return 1;
  3248	}
  3249	

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