diff mbox series

[4/4] mm/mempolicy: Use vma_alloc_folio() in new_page()

Message ID 20220404193006.1429250-5-willy@infradead.org (mailing list archive)
State New
Headers show
Series Alternative fixes for migration | expand

Commit Message

Matthew Wilcox April 4, 2022, 7:30 p.m. UTC 
Simplify new_page() by unifying the THP and base page cases, and
handle orders other than 0 and HPAGE_PMD_ORDER correctly.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 mm/mempolicy.c | 25 +++++++++++--------------
 1 file changed, 11 insertions(+), 14 deletions(-)

Comments

Zi Yan April 4, 2022, 7:51 p.m. UTC | #1 
On 4 Apr 2022, at 15:30, Matthew Wilcox (Oracle) wrote:

> Simplify new_page() by unifying the THP and base page cases, and
> handle orders other than 0 and HPAGE_PMD_ORDER correctly.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
>  mm/mempolicy.c | 25 +++++++++++--------------
>  1 file changed, 11 insertions(+), 14 deletions(-)
>
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index ec15f4f4b714..d6d7a95b0cce 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -1191,8 +1191,10 @@ int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
>   */
>  static struct page *new_page(struct page *page, unsigned long start)
>  {
> +	struct folio *dst, *src = page_folio(page);
>  	struct vm_area_struct *vma;
>  	unsigned long address;
> +	gfp_t gfp = GFP_HIGHUSER_MOVABLE | __GFP_RETRY_MAYFAIL;
>
>  	vma = find_vma(current->mm, start);
>  	while (vma) {
> @@ -1202,24 +1204,19 @@ static struct page *new_page(struct page *page, unsigned long start)
>  		vma = vma->vm_next;
>  	}
>
> -	if (PageHuge(page)) {
> -		return alloc_huge_page_vma(page_hstate(compound_head(page)),
> +	if (folio_test_hugetlb(src)) {
> +		return alloc_huge_page_vma(page_hstate(&src->page),
>  				vma, address);
> -	} else if (PageTransHuge(page)) {
> -		struct page *thp;
> -
> -		thp = alloc_hugepage_vma(GFP_TRANSHUGE, vma, address,
> -					 HPAGE_PMD_ORDER);
> -		if (!thp)
> -			return NULL;
> -		prep_transhuge_page(thp);
> -		return thp;
> +	} else if (folio_test_large(src)) {
> +		gfp = GFP_TRANSHUGE;
>  	}

Nit. The two bracket pairs from the two ifs can be removed.

> +
>  	/*
> -	 * if !vma, alloc_page_vma() will use task or system default policy
> +	 * if !vma, vma_alloc_folio() will use task or system default policy
>  	 */
> -	return alloc_page_vma(GFP_HIGHUSER_MOVABLE | __GFP_RETRY_MAYFAIL,
> -			vma, address);
> +	dst = vma_alloc_folio(gfp, folio_order(src), vma, address,
> +			folio_test_large(src));
> +	return &dst->page;
>  }
>  #else
>
> -- 
> 2.34.1


--
Best Regards,
Yan, Zi
Matthew Wilcox April 7, 2022, 1:11 p.m. UTC | #2 
On Mon, Apr 04, 2022 at 03:51:30PM -0400, Zi Yan wrote:
> On 4 Apr 2022, at 15:30, Matthew Wilcox (Oracle) wrote:
> >
> > -	if (PageHuge(page)) {
> > -		return alloc_huge_page_vma(page_hstate(compound_head(page)),
> > +	if (folio_test_hugetlb(src)) {
> > +		return alloc_huge_page_vma(page_hstate(&src->page),
> >  				vma, address);
> > -	} else if (PageTransHuge(page)) {
> > -		struct page *thp;
> > -
> > -		thp = alloc_hugepage_vma(GFP_TRANSHUGE, vma, address,
> > -					 HPAGE_PMD_ORDER);
> > -		if (!thp)
> > -			return NULL;
> > -		prep_transhuge_page(thp);
> > -		return thp;
> > +	} else if (folio_test_large(src)) {
> > +		gfp = GFP_TRANSHUGE;
> >  	}
> 
> Nit. The two bracket pairs from the two ifs can be removed.

Even better, the first is a return, so it can simply be:

        if (folio_test_hugetlb(src))
                return alloc_huge_page_vma(page_hstate(&src->page),
                                vma, address);

        if (folio_test_large(src))
                gfp = GFP_TRANSHUGE;

        dst = vma_alloc_folio(gfp, folio_order(src), vma, address,
                        folio_test_large(src));
diff mbox series

Patch

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index ec15f4f4b714..d6d7a95b0cce 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1191,8 +1191,10 @@  int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
  */
 static struct page *new_page(struct page *page, unsigned long start)
 {
+	struct folio *dst, *src = page_folio(page);
 	struct vm_area_struct *vma;
 	unsigned long address;
+	gfp_t gfp = GFP_HIGHUSER_MOVABLE | __GFP_RETRY_MAYFAIL;
 
 	vma = find_vma(current->mm, start);
 	while (vma) {
@@ -1202,24 +1204,19 @@  static struct page *new_page(struct page *page, unsigned long start)
 		vma = vma->vm_next;
 	}
 
-	if (PageHuge(page)) {
-		return alloc_huge_page_vma(page_hstate(compound_head(page)),
+	if (folio_test_hugetlb(src)) {
+		return alloc_huge_page_vma(page_hstate(&src->page),
 				vma, address);
-	} else if (PageTransHuge(page)) {
-		struct page *thp;
-
-		thp = alloc_hugepage_vma(GFP_TRANSHUGE, vma, address,
-					 HPAGE_PMD_ORDER);
-		if (!thp)
-			return NULL;
-		prep_transhuge_page(thp);
-		return thp;
+	} else if (folio_test_large(src)) {
+		gfp = GFP_TRANSHUGE;
 	}
+
 	/*
-	 * if !vma, alloc_page_vma() will use task or system default policy
+	 * if !vma, vma_alloc_folio() will use task or system default policy
 	 */
-	return alloc_page_vma(GFP_HIGHUSER_MOVABLE | __GFP_RETRY_MAYFAIL,
-			vma, address);
+	dst = vma_alloc_folio(gfp, folio_order(src), vma, address,
+			folio_test_large(src));
+	return &dst->page;
 }
 #else