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

[Kefeng Wang <wangkefeng.wang@huawei.com>]

On 2024/1/17 5:26, kernel test robot wrote:
> 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 >>):
> 


thanks, will fix built on !CONFIG_TRANSPARENT_HUGEPAGE

>     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	
>