[PATCH v3 3/4] mm/memory: convert do_shared_fault() to folios

From: Sidhartha Kumar
Date: Thu Jul 06 2023 - 12:40:08 EST


Saves three implicit calls to compound_head().

Signed-off-by: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
Reviewed-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
v2:
- move folio initialization after __do_fault()
mm/memory.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index 673b9fa67d0d7..a59b10e534c07 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4607,21 +4607,24 @@ static vm_fault_t do_shared_fault(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
vm_fault_t ret, tmp;
+ struct folio *folio;

ret = __do_fault(vmf);
if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY)))
return ret;

+ folio = page_folio(vmf->page);
+
/*
* Check if the backing address space wants to know that the page is
* about to become writable
*/
if (vma->vm_ops->page_mkwrite) {
- unlock_page(vmf->page);
+ folio_unlock(folio);
tmp = do_page_mkwrite(vmf);
if (unlikely(!tmp ||
(tmp & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) {
- put_page(vmf->page);
+ folio_put(folio);
return tmp;
}
}
@@ -4629,8 +4632,8 @@ static vm_fault_t do_shared_fault(struct vm_fault *vmf)
ret |= finish_fault(vmf);
if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE |
VM_FAULT_RETRY))) {
- unlock_page(vmf->page);
- put_page(vmf->page);
+ folio_unlock(folio);
+ folio_put(folio);
return ret;
}

--
2.41.0