Re: [PATCHv5 09/28] thp: rename split_huge_page_pmd() to split_huge_pmd()

[Vlastimil Babka <vbabka@suse.cz>]

On 04/23/2015 11:03 PM, Kirill A. Shutemov wrote:
> We are going to decouple splitting THP PMD from splitting underlying
> compound page.
>
> This patch renames split_huge_page_pmd*() functions to split_huge_pmd*()
> to reflect the fact that it doesn't imply page splitting, only PMD.
>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Tested-by: Sasha Levin <sasha.levin@oracle.com>

Acked-by: Vlastimil Babka <vbabka@suse.cz>

> ---
>   arch/powerpc/mm/subpage-prot.c |  2 +-
>   arch/x86/kernel/vm86_32.c      |  6 +++++-
>   include/linux/huge_mm.h        |  8 ++------
>   mm/gup.c                       |  2 +-
>   mm/huge_memory.c               | 32 +++++++++++---------------------
>   mm/madvise.c                   |  2 +-
>   mm/memory.c                    |  2 +-
>   mm/mempolicy.c                 |  2 +-
>   mm/mprotect.c                  |  2 +-
>   mm/mremap.c                    |  2 +-
>   mm/pagewalk.c                  |  2 +-
>   11 files changed, 26 insertions(+), 36 deletions(-)
>
> diff --git a/arch/powerpc/mm/subpage-prot.c b/arch/powerpc/mm/subpage-prot.c
> index fa9fb5b4c66c..d5543514c1df 100644
> --- a/arch/powerpc/mm/subpage-prot.c
> +++ b/arch/powerpc/mm/subpage-prot.c
> @@ -135,7 +135,7 @@ static int subpage_walk_pmd_entry(pmd_t *pmd, unsigned long addr,
>   				  unsigned long end, struct mm_walk *walk)
>   {
>   	struct vm_area_struct *vma = walk->vma;
> -	split_huge_page_pmd(vma, addr, pmd);
> +	split_huge_pmd(vma, pmd, addr);
>   	return 0;
>   }
>
> diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c
> index e8edcf52e069..883160599965 100644
> --- a/arch/x86/kernel/vm86_32.c
> +++ b/arch/x86/kernel/vm86_32.c
> @@ -182,7 +182,11 @@ static void mark_screen_rdonly(struct mm_struct *mm)
>   	if (pud_none_or_clear_bad(pud))
>   		goto out;
>   	pmd = pmd_offset(pud, 0xA0000);
> -	split_huge_page_pmd_mm(mm, 0xA0000, pmd);
> +
> +	if (pmd_trans_huge(*pmd)) {
> +		struct vm_area_struct *vma = find_vma(mm, 0xA0000);
> +		split_huge_pmd(vma, pmd, 0xA0000);
> +	}
>   	if (pmd_none_or_clear_bad(pmd))
>   		goto out;
>   	pte = pte_offset_map_lock(mm, pmd, 0xA0000, &ptl);
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index 44a840a53974..34bbf769d52e 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -104,7 +104,7 @@ static inline int split_huge_page(struct page *page)
>   }
>   extern void __split_huge_page_pmd(struct vm_area_struct *vma,
>   		unsigned long address, pmd_t *pmd);
> -#define split_huge_page_pmd(__vma, __address, __pmd)			\
> +#define split_huge_pmd(__vma, __pmd, __address)				\
>   	do {								\
>   		pmd_t *____pmd = (__pmd);				\
>   		if (unlikely(pmd_trans_huge(*____pmd)))			\
> @@ -119,8 +119,6 @@ extern void __split_huge_page_pmd(struct vm_area_struct *vma,
>   		BUG_ON(pmd_trans_splitting(*____pmd) ||			\
>   		       pmd_trans_huge(*____pmd));			\
>   	} while (0)
> -extern void split_huge_page_pmd_mm(struct mm_struct *mm, unsigned long address,
> -		pmd_t *pmd);
>   #if HPAGE_PMD_ORDER >= MAX_ORDER
>   #error "hugepages can't be allocated by the buddy allocator"
>   #endif
> @@ -187,11 +185,9 @@ static inline int split_huge_page(struct page *page)
>   {
>   	return 0;
>   }
> -#define split_huge_page_pmd(__vma, __address, __pmd)	\
> -	do { } while (0)
>   #define wait_split_huge_page(__anon_vma, __pmd)	\
>   	do { } while (0)
> -#define split_huge_page_pmd_mm(__mm, __address, __pmd)	\
> +#define split_huge_pmd(__vma, __pmd, __address)	\
>   	do { } while (0)
>   static inline int hugepage_madvise(struct vm_area_struct *vma,
>   				   unsigned long *vm_flags, int advice)
> diff --git a/mm/gup.c b/mm/gup.c
> index 7334eb24f414..19e01f156abb 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -220,7 +220,7 @@ struct page *follow_page_mask(struct vm_area_struct *vma,
>   		if (is_huge_zero_page(page)) {
>   			spin_unlock(ptl);
>   			ret = 0;
> -			split_huge_page_pmd(vma, address, pmd);
> +			split_huge_pmd(vma, pmd, address);
>   		} else {
>   			get_page(page);
>   			spin_unlock(ptl);
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index ffc30e4462c1..ccbfacf07160 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -1136,13 +1136,13 @@ alloc:
>
>   	if (unlikely(!new_page)) {
>   		if (!page) {
> -			split_huge_page_pmd(vma, address, pmd);
> +			split_huge_pmd(vma, pmd, address);
>   			ret |= VM_FAULT_FALLBACK;
>   		} else {
>   			ret = do_huge_pmd_wp_page_fallback(mm, vma, address,
>   					pmd, orig_pmd, page, haddr);
>   			if (ret & VM_FAULT_OOM) {
> -				split_huge_page(page);
> +				split_huge_pmd(vma, pmd, address);
>   				ret |= VM_FAULT_FALLBACK;
>   			}
>   			put_user_huge_page(page);
> @@ -1155,10 +1155,10 @@ alloc:
>   					&memcg, true))) {
>   		put_page(new_page);
>   		if (page) {
> -			split_huge_page(page);
> +			split_huge_pmd(vma, pmd, address);
>   			put_user_huge_page(page);
>   		} else
> -			split_huge_page_pmd(vma, address, pmd);
> +			split_huge_pmd(vma, pmd, address);
>   		ret |= VM_FAULT_FALLBACK;
>   		count_vm_event(THP_FAULT_FALLBACK);
>   		goto out;
> @@ -2985,17 +2985,7 @@ again:
>   		goto again;
>   }
>
> -void split_huge_page_pmd_mm(struct mm_struct *mm, unsigned long address,
> -		pmd_t *pmd)
> -{
> -	struct vm_area_struct *vma;
> -
> -	vma = find_vma(mm, address);
> -	BUG_ON(vma == NULL);
> -	split_huge_page_pmd(vma, address, pmd);
> -}
> -
> -static void split_huge_page_address(struct mm_struct *mm,
> +static void split_huge_pmd_address(struct vm_area_struct *vma,
>   				    unsigned long address)
>   {
>   	pgd_t *pgd;
> @@ -3004,7 +2994,7 @@ static void split_huge_page_address(struct mm_struct *mm,
>
>   	VM_BUG_ON(!(address & ~HPAGE_PMD_MASK));
>
> -	pgd = pgd_offset(mm, address);
> +	pgd = pgd_offset(vma->vm_mm, address);
>   	if (!pgd_present(*pgd))
>   		return;
>
> @@ -3013,13 +3003,13 @@ static void split_huge_page_address(struct mm_struct *mm,
>   		return;
>
>   	pmd = pmd_offset(pud, address);
> -	if (!pmd_present(*pmd))
> +	if (!pmd_present(*pmd) || !pmd_trans_huge(*pmd))
>   		return;
>   	/*
>   	 * Caller holds the mmap_sem write mode, so a huge pmd cannot
>   	 * materialize from under us.
>   	 */
> -	split_huge_page_pmd_mm(mm, address, pmd);
> +	__split_huge_page_pmd(vma, address, pmd);
>   }
>
>   void __vma_adjust_trans_huge(struct vm_area_struct *vma,
> @@ -3035,7 +3025,7 @@ void __vma_adjust_trans_huge(struct vm_area_struct *vma,
>   	if (start & ~HPAGE_PMD_MASK &&
>   	    (start & HPAGE_PMD_MASK) >= vma->vm_start &&
>   	    (start & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE <= vma->vm_end)
> -		split_huge_page_address(vma->vm_mm, start);
> +		split_huge_pmd_address(vma, start);
>
>   	/*
>   	 * If the new end address isn't hpage aligned and it could
> @@ -3045,7 +3035,7 @@ void __vma_adjust_trans_huge(struct vm_area_struct *vma,
>   	if (end & ~HPAGE_PMD_MASK &&
>   	    (end & HPAGE_PMD_MASK) >= vma->vm_start &&
>   	    (end & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE <= vma->vm_end)
> -		split_huge_page_address(vma->vm_mm, end);
> +		split_huge_pmd_address(vma, end);
>
>   	/*
>   	 * If we're also updating the vma->vm_next->vm_start, if the new
> @@ -3059,6 +3049,6 @@ void __vma_adjust_trans_huge(struct vm_area_struct *vma,
>   		if (nstart & ~HPAGE_PMD_MASK &&
>   		    (nstart & HPAGE_PMD_MASK) >= next->vm_start &&
>   		    (nstart & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE <= next->vm_end)
> -			split_huge_page_address(next->vm_mm, nstart);
> +			split_huge_pmd_address(next, nstart);
>   	}
>   }
> diff --git a/mm/madvise.c b/mm/madvise.c
> index 22b86daf6b94..f5a81ca0dca7 100644
> --- a/mm/madvise.c
> +++ b/mm/madvise.c
> @@ -281,7 +281,7 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr,
>   	next = pmd_addr_end(addr, end);
>   	if (pmd_trans_huge(*pmd)) {
>   		if (next - addr != HPAGE_PMD_SIZE)
> -			split_huge_page_pmd(vma, addr, pmd);
> +			split_huge_pmd(vma, pmd, addr);
>   		else if (!madvise_free_huge_pmd(tlb, vma, pmd, addr))
>   			goto next;
>   		/* fall through */
> diff --git a/mm/memory.c b/mm/memory.c
> index 8bbd3f88544b..61e7ed722760 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -1201,7 +1201,7 @@ static inline unsigned long zap_pmd_range(struct mmu_gather *tlb,
>   					BUG();
>   				}
>   #endif
> -				split_huge_page_pmd(vma, addr, pmd);
> +				split_huge_pmd(vma, pmd, addr);
>   			} else if (zap_huge_pmd(tlb, vma, pmd, addr))
>   				goto next;
>   			/* fall through */
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index 8badb84c013e..aac490fdc91f 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -493,7 +493,7 @@ static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr,
>   	pte_t *pte;
>   	spinlock_t *ptl;
>
> -	split_huge_page_pmd(vma, addr, pmd);
> +	split_huge_pmd(vma, pmd, addr);
>   	if (pmd_trans_unstable(pmd))
>   		return 0;
>
> diff --git a/mm/mprotect.c b/mm/mprotect.c
> index 88584838e704..714d2fbbaafd 100644
> --- a/mm/mprotect.c
> +++ b/mm/mprotect.c
> @@ -158,7 +158,7 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
>
>   		if (pmd_trans_huge(*pmd)) {
>   			if (next - addr != HPAGE_PMD_SIZE)
> -				split_huge_page_pmd(vma, addr, pmd);
> +				split_huge_pmd(vma, pmd, addr);
>   			else {
>   				int nr_ptes = change_huge_pmd(vma, pmd, addr,
>   						newprot, prot_numa);
> diff --git a/mm/mremap.c b/mm/mremap.c
> index afa3ab740d8c..3e40ea27edc4 100644
> --- a/mm/mremap.c
> +++ b/mm/mremap.c
> @@ -208,7 +208,7 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
>   				need_flush = true;
>   				continue;
>   			} else if (!err) {
> -				split_huge_page_pmd(vma, old_addr, old_pmd);
> +				split_huge_pmd(vma, old_pmd, old_addr);
>   			}
>   			VM_BUG_ON(pmd_trans_huge(*old_pmd));
>   		}
> diff --git a/mm/pagewalk.c b/mm/pagewalk.c
> index 29f2f8b853ae..207244489a68 100644
> --- a/mm/pagewalk.c
> +++ b/mm/pagewalk.c
> @@ -58,7 +58,7 @@ again:
>   		if (!walk->pte_entry)
>   			continue;
>
> -		split_huge_page_pmd_mm(walk->mm, addr, pmd);
> +		split_huge_pmd(walk->vma, pmd, addr);
>   		if (pmd_trans_unstable(pmd))
>   			goto again;
>   		err = walk_pte_range(pmd, addr, next, walk);
>

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