From b4b9df5ce44398fa4e663e0b9fa2d4099e0d7b51 Mon Sep 17 00:00:00 2001
From: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Date: Wed, 22 Mar 2006 00:09:03 -0800
Subject: [PATCH] --- yaml --- r: 22495 b: refs/heads/master c:
 d5d4b0aa4e1430d73050babba999365593bdb9d2 h: refs/heads/master i:   22493:
 efeed542cbcc1b8e2ae62f1e604a701bf9d45358   22491:
 e543fe7d072ada5b6faa20c118bebc07d573bfc7   22487:
 499fe090d42ff6099ab00bb5086ec3f6fc38f8bc   22479:
 52afa3e65ed5b47e116dd844c189aa106b3f65a3   22463:
 e2472809f05790c6246473742d3cb38c12996b3f v: v3

---
 [refs]             |  2 +-
 trunk/mm/hugetlb.c | 25 +++++++++++++++++--------
 2 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/[refs] b/[refs]
index 6808440409f2..534d96450575 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: bba1e9b2111b14625f670bd07e57fd7ed57ce804
+refs/heads/master: d5d4b0aa4e1430d73050babba999365593bdb9d2
diff --git a/trunk/mm/hugetlb.c b/trunk/mm/hugetlb.c
index 075877b1cbc0..06699d871a8e 100644
--- a/trunk/mm/hugetlb.c
+++ b/trunk/mm/hugetlb.c
@@ -661,10 +661,10 @@ int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
 			struct page **pages, struct vm_area_struct **vmas,
 			unsigned long *position, int *length, int i)
 {
-	unsigned long vpfn, vaddr = *position;
+	unsigned long pfn_offset;
+	unsigned long vaddr = *position;
 	int remainder = *length;
 
-	vpfn = vaddr/PAGE_SIZE;
 	spin_lock(&mm->page_table_lock);
 	while (vaddr < vma->vm_end && remainder) {
 		pte_t *pte;
@@ -692,19 +692,28 @@ int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
 			break;
 		}
 
-		if (pages) {
-			page = &pte_page(*pte)[vpfn % (HPAGE_SIZE/PAGE_SIZE)];
-			get_page(page);
-			pages[i] = page;
-		}
+		pfn_offset = (vaddr & ~HPAGE_MASK) >> PAGE_SHIFT;
+		page = pte_page(*pte);
+same_page:
+		get_page(page);
+		if (pages)
+			pages[i] = page + pfn_offset;
 
 		if (vmas)
 			vmas[i] = vma;
 
 		vaddr += PAGE_SIZE;
-		++vpfn;
+		++pfn_offset;
 		--remainder;
 		++i;
+		if (vaddr < vma->vm_end && remainder &&
+				pfn_offset < HPAGE_SIZE/PAGE_SIZE) {
+			/*
+			 * We use pfn_offset to avoid touching the pageframes
+			 * of this compound page.
+			 */
+			goto same_page;
+		}
 	}
 	spin_unlock(&mm->page_table_lock);
 	*length = remainder;