linux-kernel - [PATCH 01/10] mm: pagewalk: consolidate vma->vm

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Date:	Mon, 02 Jun 2014 14:36:45 -0700
From:	Dave Hansen <dave@...1.net>
To:	linux-kernel@...r.kernel.org
Cc:	linux-mm@...ck.org, kirill.shutemov@...ux.intel.com,
	Dave Hansen <dave@...1.net>
Subject: [PATCH 01/10] mm: pagewalk: consolidate vma->vm_start checks


From: Dave Hansen <dave.hansen@...ux.intel.com>

We check vma->vm_start against the address being walked twice.
Consolidate the locations down to a single one.

Signed-off-by: Dave Hansen <dave.hansen@...ux.intel.com>
---

 b/mm/pagewalk.c |    8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff -puN mm/pagewalk.c~pagewalk-always-skip-hugetlbfs-except-when-explicitly-handled mm/pagewalk.c
--- a/mm/pagewalk.c~pagewalk-always-skip-hugetlbfs-except-when-explicitly-handled	2014-06-02 14:20:18.938791410 -0700
+++ b/mm/pagewalk.c	2014-06-02 14:20:18.941791545 -0700
@@ -192,13 +192,12 @@ int walk_page_range(unsigned long addr,
 		 * - VM_PFNMAP vma's
 		 */
 		vma = find_vma(walk->mm, addr);
-		if (vma) {
+		if (vma && (vma->vm_start <= addr)) {
 			/*
 			 * There are no page structures backing a VM_PFNMAP
 			 * range, so do not allow split_huge_page_pmd().
 			 */
-			if ((vma->vm_start <= addr) &&
-			    (vma->vm_flags & VM_PFNMAP)) {
+			if (vma->vm_flags & VM_PFNMAP) {
 				next = vma->vm_end;
 				pgd = pgd_offset(walk->mm, next);
 				continue;
@@ -209,8 +208,7 @@ int walk_page_range(unsigned long addr,
 			 * architecture and we can't handled it in the same
 			 * manner as non-huge pages.
 			 */
-			if (walk->hugetlb_entry && (vma->vm_start <= addr) &&
-			    is_vm_hugetlb_page(vma)) {
+			if (walk->hugetlb_entry && is_vm_hugetlb_page(vma)) {
 				if (vma->vm_end < next)
 					next = vma->vm_end;
 				/*
_
--
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