Re: [PATCH] mm: memory: move mem_cgroup_charge() into alloc_anon_folio()

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

Hi Kefeng,

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/Kefeng-Wang/mm-memory-move-mem_cgroup_charge-into-alloc_anon_folio/20240116-151640
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20240116071302.2282230-1-wangkefeng.wang%40huawei.com
patch subject: [PATCH] mm: memory: move mem_cgroup_charge() into alloc_anon_folio()
config: x86_64-allnoconfig (https://download.01.org/0day-ci/archive/20240117/202401170535.2TfJ7u74-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240117/202401170535.2TfJ7u74-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/202401170535.2TfJ7u74-lkp@intel.com/

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

   mm/memory.c: In function 'alloc_anon_folio':
>> mm/memory.c:4223:31: error: 'vma' undeclared (first use in this function); did you mean 'vmf'?
    4223 |         return folio_prealloc(vma->vm_mm, vma, vmf->address, true);
         |                               ^~~
         |                               vmf
   mm/memory.c:4223:31: note: each undeclared identifier is reported only once for each function it appears in
>> mm/memory.c:4224:1: warning: control reaches end of non-void function [-Wreturn-type]
    4224 | }
         | ^


vim +4223 mm/memory.c

  4153	
  4154	static struct folio *alloc_anon_folio(struct vm_fault *vmf)
  4155	{
  4156	#ifdef CONFIG_TRANSPARENT_HUGEPAGE
  4157		struct vm_area_struct *vma = vmf->vma;
  4158		unsigned long orders;
  4159		struct folio *folio;
  4160		unsigned long addr;
  4161		pte_t *pte;
  4162		gfp_t gfp;
  4163		int order;
  4164	
  4165		/*
  4166		 * If uffd is active for the vma we need per-page fault fidelity to
  4167		 * maintain the uffd semantics.
  4168		 */
  4169		if (unlikely(userfaultfd_armed(vma)))
  4170			goto fallback;
  4171	
  4172		/*
  4173		 * Get a list of all the (large) orders below PMD_ORDER that are enabled
  4174		 * for this vma. Then filter out the orders that can't be allocated over
  4175		 * the faulting address and still be fully contained in the vma.
  4176		 */
  4177		orders = thp_vma_allowable_orders(vma, vma->vm_flags, false, true, true,
  4178						  BIT(PMD_ORDER) - 1);
  4179		orders = thp_vma_suitable_orders(vma, vmf->address, orders);
  4180	
  4181		if (!orders)
  4182			goto fallback;
  4183	
  4184		pte = pte_offset_map(vmf->pmd, vmf->address & PMD_MASK);
  4185		if (!pte)
  4186			return ERR_PTR(-EAGAIN);
  4187	
  4188		/*
  4189		 * Find the highest order where the aligned range is completely
  4190		 * pte_none(). Note that all remaining orders will be completely
  4191		 * pte_none().
  4192		 */
  4193		order = highest_order(orders);
  4194		while (orders) {
  4195			addr = ALIGN_DOWN(vmf->address, PAGE_SIZE << order);
  4196			if (pte_range_none(pte + pte_index(addr), 1 << order))
  4197				break;
  4198			order = next_order(&orders, order);
  4199		}
  4200	
  4201		pte_unmap(pte);
  4202	
  4203		/* Try allocating the highest of the remaining orders. */
  4204		gfp = vma_thp_gfp_mask(vma);
  4205		while (orders) {
  4206			addr = ALIGN_DOWN(vmf->address, PAGE_SIZE << order);
  4207			folio = vma_alloc_folio(gfp, order, vma, addr, true);
  4208			if (folio) {
  4209				if (mem_cgroup_charge(folio, vma->vm_mm, gfp)) {
  4210					folio_put(folio);
  4211					goto next;
  4212				}
  4213				folio_throttle_swaprate(folio, gfp);
  4214				clear_huge_page(&folio->page, vmf->address, 1 << order);
  4215				return folio;
  4216			}
  4217	next:
  4218			order = next_order(&orders, order);
  4219		}
  4220	
  4221	fallback:
  4222	#endif
> 4223		return folio_prealloc(vma->vm_mm, vma, vmf->address, true);
> 4224	}
  4225	

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