[PATCH v3 4/4] mm/memory: convert do_read_fault() to use folios

From: Sidhartha Kumar
Date: Thu Jul 06 2023 - 12:40:11 EST


Saves one implicit call to compound_head()

Signed-off-by: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
Reviewed-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
v3:
- move folio initialization after finish_fault()
v2
- move folio initialization after __do_fault()
mm/memory.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index a59b10e534c07..64e1eb840dec7 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4541,6 +4541,7 @@ static inline bool should_fault_around(struct vm_fault *vmf)
static vm_fault_t do_read_fault(struct vm_fault *vmf)
{
vm_fault_t ret = 0;
+ struct folio *folio;

/*
* Let's call ->map_pages() first and use ->fault() as fallback
@@ -4558,9 +4559,10 @@ static vm_fault_t do_read_fault(struct vm_fault *vmf)
return ret;

ret |= finish_fault(vmf);
- unlock_page(vmf->page);
+ folio = page_folio(vmf->page);
+ folio_unlock(folio);
if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY)))
- put_page(vmf->page);
+ folio_put(folio);
return ret;
}

--
2.41.0