[v2,2/4] mm/memory: convert wp_page_shared() to use folios

Commit Message

Sidhartha Kumar July 5, 2023, 7:43 p.m. UTC

Saves five implicit calls to compound_head().

Signed-off-by: Sidhartha Kumar <[e-mail]>
---
	v2:
		- change function definition to pass in a folio

 mm/memory.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

Comments

Matthew Wilcox July 5, 2023, 8:03 p.m. UTC | #1

On Wed, Jul 05, 2023 at 12:43:33PM -0700, Sidhartha Kumar wrote:
> @@ -3375,7 +3375,7 @@ static vm_fault_t do_wp_page(struct vm_fault *vmf)
>  		 */
>  		if (!vmf->page)
>  			return wp_pfn_shared(vmf);
> -		return wp_page_shared(vmf);
> +		return wp_page_shared(vmf, page_folio(vmf->page));
>  	}
>  
>  	if (vmf->page)

I was actually hoping you'd move:

        if (vmf->page)
                folio = page_folio(vmf->page);

up to immediately after the call to vm_normal_page(), and avoid even
this call to page_folio().

Patch

diff --git a/mm/memory.c b/mm/memory.c
index e73245b791a7a..fba33fb55a010 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3281,13 +3281,13 @@  static vm_fault_t wp_pfn_shared(struct vm_fault *vmf)
 	return 0;
 }
 
-static vm_fault_t wp_page_shared(struct vm_fault *vmf)
+static vm_fault_t wp_page_shared(struct vm_fault *vmf, struct folio *folio)
 	__releases(vmf->ptl)
 {
 	struct vm_area_struct *vma = vmf->vma;
 	vm_fault_t ret = 0;
 
-	get_page(vmf->page);
+	folio_get(folio);
 
 	if (vma->vm_ops && vma->vm_ops->page_mkwrite) {
 		vm_fault_t tmp;
@@ -3296,21 +3296,21 @@  static vm_fault_t wp_page_shared(struct vm_fault *vmf)
 		tmp = do_page_mkwrite(vmf);
 		if (unlikely(!tmp || (tmp &
 				      (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) {
-			put_page(vmf->page);
+			folio_put(folio);
 			return tmp;
 		}
 		tmp = finish_mkwrite_fault(vmf);
 		if (unlikely(tmp & (VM_FAULT_ERROR | VM_FAULT_NOPAGE))) {
-			unlock_page(vmf->page);
-			put_page(vmf->page);
+			folio_unlock(folio);
+			folio_put(folio);
 			return tmp;
 		}
 	} else {
 		wp_page_reuse(vmf);
-		lock_page(vmf->page);
+		folio_lock(folio);
 	}
 	ret |= fault_dirty_shared_page(vmf);
-	put_page(vmf->page);
+	folio_put(folio);
 
 	return ret;
 }
@@ -3375,7 +3375,7 @@  static vm_fault_t do_wp_page(struct vm_fault *vmf)
 		 */
 		if (!vmf->page)
 			return wp_pfn_shared(vmf);
-		return wp_page_shared(vmf);
+		return wp_page_shared(vmf, page_folio(vmf->page));
 	}
 
 	if (vmf->page)