From 276f756d7002ceb66f8ae3f7bd8028e7ae3deed8 Mon Sep 17 00:00:00 2001
From: Pingfan Liu <kernelfans@gmail.com>
Date: Mon, 23 Sep 2019 15:37:38 -0700
Subject: [PATCH] mm/migrate.c: clean up useless code in
 migrate_vma_collect_pmd()
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Remove unused 'pfn' variable.

Link: http://lkml.kernel.org/r/1565167272-21453-1-git-send-email-kernelfans@gmail.com
Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Jan Kara <jack@suse.cz>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 mm/migrate.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 374ef2f..73d476d 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2218,17 +2218,15 @@ again:
 		pte_t pte;
 
 		pte = *ptep;
-		pfn = pte_pfn(pte);
 
 		if (pte_none(pte)) {
 			mpfn = MIGRATE_PFN_MIGRATE;
 			migrate->cpages++;
-			pfn = 0;
 			goto next;
 		}
 
 		if (!pte_present(pte)) {
-			mpfn = pfn = 0;
+			mpfn = 0;
 
 			/*
 			 * Only care about unaddressable device page special
@@ -2245,10 +2243,10 @@ again:
 			if (is_write_device_private_entry(entry))
 				mpfn |= MIGRATE_PFN_WRITE;
 		} else {
+			pfn = pte_pfn(pte);
 			if (is_zero_pfn(pfn)) {
 				mpfn = MIGRATE_PFN_MIGRATE;
 				migrate->cpages++;
-				pfn = 0;
 				goto next;
 			}
 			page = vm_normal_page(migrate->vma, addr, pte);
@@ -2258,10 +2256,9 @@ again:
 
 		/* FIXME support THP */
 		if (!page || !page->mapping || PageTransCompound(page)) {
-			mpfn = pfn = 0;
+			mpfn = 0;
 			goto next;
 		}
-		pfn = page_to_pfn(page);
 
 		/*
 		 * By getting a reference on the page we pin it and that blocks
-- 
2.7.4