diff mbox series

[v2,20/28] gup: Convert gup_pte_range() to use a folio

Message ID 20220110042406.499429-21-willy@infradead.org (mailing list archive)
State New
Headers show
Series Convert GUP to folios | expand

Commit Message

Matthew Wilcox (Oracle) Jan. 10, 2022, 4:23 a.m. UTC 
We still call try_grab_folio() once per PTE; a future patch could
optimise to just adjust the reference count for each page within
the folio.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 mm/gup.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

Comments

Christoph Hellwig Jan. 10, 2022, 8:37 a.m. UTC | #1 
On Mon, Jan 10, 2022 at 04:23:58AM +0000, Matthew Wilcox (Oracle) wrote:
> We still call try_grab_folio() once per PTE; a future patch could
> optimise to just adjust the reference count for each page within
> the folio.

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>
John Hubbard Jan. 11, 2022, 7:06 a.m. UTC | #2 
On 1/9/22 20:23, Matthew Wilcox (Oracle) wrote:
> We still call try_grab_folio() once per PTE; a future patch could
> optimise to just adjust the reference count for each page within
> the folio.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
>   mm/gup.c | 16 +++++++---------
>   1 file changed, 7 insertions(+), 9 deletions(-)

Still looks good.

Reviewed-by: John Hubbard <jhubbard@nvidia.com>


thanks,
diff mbox series

Patch

diff --git a/mm/gup.c b/mm/gup.c
index c3e514172eaf..27cc097ec05d 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -2235,7 +2235,8 @@  static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
 	ptem = ptep = pte_offset_map(&pmd, addr);
 	do {
 		pte_t pte = ptep_get_lockless(ptep);
-		struct page *head, *page;
+		struct page *page;
+		struct folio *folio;
 
 		/*
 		 * Similar to the PMD case below, NUMA hinting must take slow
@@ -2262,22 +2263,20 @@  static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
 		VM_BUG_ON(!pfn_valid(pte_pfn(pte)));
 		page = pte_page(pte);
 
-		head = try_grab_compound_head(page, 1, flags);
-		if (!head)
+		folio = try_grab_folio(page, 1, flags);
+		if (!folio)
 			goto pte_unmap;
 
 		if (unlikely(page_is_secretmem(page))) {
-			put_compound_head(head, 1, flags);
+			gup_put_folio(folio, 1, flags);
 			goto pte_unmap;
 		}
 
 		if (unlikely(pte_val(pte) != pte_val(*ptep))) {
-			put_compound_head(head, 1, flags);
+			gup_put_folio(folio, 1, flags);
 			goto pte_unmap;
 		}
 
-		VM_BUG_ON_PAGE(compound_head(page) != head, page);
-
 		/*
 		 * We need to make the page accessible if and only if we are
 		 * going to access its content (the FOLL_PIN case).  Please
@@ -2291,10 +2290,9 @@  static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
 				goto pte_unmap;
 			}
 		}
-		SetPageReferenced(page);
+		folio_set_referenced(folio);
 		pages[*nr] = page;
 		(*nr)++;
-
 	} while (ptep++, addr += PAGE_SIZE, addr != end);
 
 	ret = 1;