On Wed, 28 Mar 2018, Laurent Dufour wrote:

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@@ -2913,7 +2921,8 @@ int do_swap_page(struct vm_fault *vmf)
 	int exclusive = 0;
 	int ret = 0;

Initialization is now unneeded.

I'm sorry, what "initialization" are you talking about here ?

The initialization of the ret variable.

@@ -2913,7 +2921,8 @@ int do_swap_page(struct vm_fault *vmf)
 	int exclusive = 0;
 	int ret = 0;

-	if (!pte_unmap_same(vma->vm_mm, vmf->pmd, vmf->pte, vmf->orig_pte))
+	ret = pte_unmap_same(vmf);
+	if (ret)
 		goto out;

 	entry = pte_to_swp_entry(vmf->orig_pte);

"ret" is immediately set to the return value of pte_unmap_same(), so there 
is no need to initialize it to 0.