summaryrefslogtreecommitdiffstats
path: root/mm/hugetlb.c
diff options
context:
space:
mode:
Diffstat (limited to 'mm/hugetlb.c')
-rw-r--r--mm/hugetlb.c25
1 files changed, 17 insertions, 8 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 075877b..06699d8 100644
--- a/mm/hugetlb.c
+++ b/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;
OpenPOWER on IntegriCloud