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Diffstat (limited to 'mm/hugetlb.c')
-rw-r--r--mm/hugetlb.c44
1 files changed, 29 insertions, 15 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 38633864a93e..ce8cbb29860b 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -262,7 +262,7 @@ struct resv_map {
struct list_head regions;
};
-struct resv_map *resv_map_alloc(void)
+static struct resv_map *resv_map_alloc(void)
{
struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL);
if (!resv_map)
@@ -274,7 +274,7 @@ struct resv_map *resv_map_alloc(void)
return resv_map;
}
-void resv_map_release(struct kref *ref)
+static void resv_map_release(struct kref *ref)
{
struct resv_map *resv_map = container_of(ref, struct resv_map, refs);
@@ -289,7 +289,7 @@ static struct resv_map *vma_resv_map(struct vm_area_struct *vma)
if (!(vma->vm_flags & VM_SHARED))
return (struct resv_map *)(get_vma_private_data(vma) &
~HPAGE_RESV_MASK);
- return 0;
+ return NULL;
}
static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map)
@@ -1459,11 +1459,11 @@ int hugetlb_report_meminfo(char *buf)
{
struct hstate *h = &default_hstate;
return sprintf(buf,
- "HugePages_Total: %5lu\n"
- "HugePages_Free: %5lu\n"
- "HugePages_Rsvd: %5lu\n"
- "HugePages_Surp: %5lu\n"
- "Hugepagesize: %5lu kB\n",
+ "HugePages_Total: %5lu\n"
+ "HugePages_Free: %5lu\n"
+ "HugePages_Rsvd: %5lu\n"
+ "HugePages_Surp: %5lu\n"
+ "Hugepagesize: %8lu kB\n",
h->nr_huge_pages,
h->free_huge_pages,
h->resv_huge_pages,
@@ -1747,10 +1747,8 @@ void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
* from other VMAs and let the children be SIGKILLed if they are faulting the
* same region.
*/
-int unmap_ref_private(struct mm_struct *mm,
- struct vm_area_struct *vma,
- struct page *page,
- unsigned long address)
+static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
+ struct page *page, unsigned long address)
{
struct vm_area_struct *iter_vma;
struct address_space *mapping;
@@ -2073,6 +2071,14 @@ follow_huge_pud(struct mm_struct *mm, unsigned long address,
return NULL;
}
+static int huge_zeropage_ok(pte_t *ptep, int write, int shared)
+{
+ if (!ptep || write || shared)
+ return 0;
+ else
+ return huge_pte_none(huge_ptep_get(ptep));
+}
+
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,
@@ -2082,6 +2088,8 @@ int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long vaddr = *position;
int remainder = *length;
struct hstate *h = hstate_vma(vma);
+ int zeropage_ok = 0;
+ int shared = vma->vm_flags & VM_SHARED;
spin_lock(&mm->page_table_lock);
while (vaddr < vma->vm_end && remainder) {
@@ -2094,8 +2102,11 @@ int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
* first, for the page indexing below to work.
*/
pte = huge_pte_offset(mm, vaddr & huge_page_mask(h));
+ if (huge_zeropage_ok(pte, write, shared))
+ zeropage_ok = 1;
- if (!pte || huge_pte_none(huge_ptep_get(pte)) ||
+ if (!pte ||
+ (huge_pte_none(huge_ptep_get(pte)) && !zeropage_ok) ||
(write && !pte_write(huge_ptep_get(pte)))) {
int ret;
@@ -2115,8 +2126,11 @@ int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
page = pte_page(huge_ptep_get(pte));
same_page:
if (pages) {
- get_page(page);
- pages[i] = page + pfn_offset;
+ if (zeropage_ok)
+ pages[i] = ZERO_PAGE(0);
+ else
+ pages[i] = page + pfn_offset;
+ get_page(pages[i]);
}
if (vmas)