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-rw-r--r--mm/hugetlb.c96
1 files changed, 78 insertions, 18 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 3863386..d143ab6 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -7,6 +7,7 @@
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mm.h>
+#include <linux/seq_file.h>
#include <linux/sysctl.h>
#include <linux/highmem.h>
#include <linux/mmu_notifier.h>
@@ -262,7 +263,7 @@ 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 +275,7 @@ 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 +290,7 @@ 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)
@@ -353,11 +354,26 @@ static int vma_has_reserves(struct vm_area_struct *vma)
return 0;
}
+static void clear_gigantic_page(struct page *page,
+ unsigned long addr, unsigned long sz)
+{
+ int i;
+ struct page *p = page;
+
+ might_sleep();
+ for (i = 0; i < sz/PAGE_SIZE; i++, p = mem_map_next(p, page, i)) {
+ cond_resched();
+ clear_user_highpage(p, addr + i * PAGE_SIZE);
+ }
+}
static void clear_huge_page(struct page *page,
unsigned long addr, unsigned long sz)
{
int i;
+ if (unlikely(sz > MAX_ORDER_NR_PAGES))
+ return clear_gigantic_page(page, addr, sz);
+
might_sleep();
for (i = 0; i < sz/PAGE_SIZE; i++) {
cond_resched();
@@ -365,12 +381,32 @@ static void clear_huge_page(struct page *page,
}
}
+static void copy_gigantic_page(struct page *dst, struct page *src,
+ unsigned long addr, struct vm_area_struct *vma)
+{
+ int i;
+ struct hstate *h = hstate_vma(vma);
+ struct page *dst_base = dst;
+ struct page *src_base = src;
+ might_sleep();
+ for (i = 0; i < pages_per_huge_page(h); ) {
+ cond_resched();
+ copy_user_highpage(dst, src, addr + i*PAGE_SIZE, vma);
+
+ i++;
+ dst = mem_map_next(dst, dst_base, i);
+ src = mem_map_next(src, src_base, i);
+ }
+}
static void copy_huge_page(struct page *dst, struct page *src,
unsigned long addr, struct vm_area_struct *vma)
{
int i;
struct hstate *h = hstate_vma(vma);
+ if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES))
+ return copy_gigantic_page(dst, src, addr, vma);
+
might_sleep();
for (i = 0; i < pages_per_huge_page(h); i++) {
cond_resched();
@@ -455,6 +491,8 @@ static void update_and_free_page(struct hstate *h, struct page *page)
{
int i;
+ VM_BUG_ON(h->order >= MAX_ORDER);
+
h->nr_huge_pages--;
h->nr_huge_pages_node[page_to_nid(page)]--;
for (i = 0; i < pages_per_huge_page(h); i++) {
@@ -969,6 +1007,14 @@ found:
return 1;
}
+static void prep_compound_huge_page(struct page *page, int order)
+{
+ if (unlikely(order > (MAX_ORDER - 1)))
+ prep_compound_gigantic_page(page, order);
+ else
+ prep_compound_page(page, order);
+}
+
/* Put bootmem huge pages into the standard lists after mem_map is up */
static void __init gather_bootmem_prealloc(void)
{
@@ -979,7 +1025,7 @@ static void __init gather_bootmem_prealloc(void)
struct hstate *h = m->hstate;
__ClearPageReserved(page);
WARN_ON(page_count(page) != 1);
- prep_compound_page(page, h->order);
+ prep_compound_huge_page(page, h->order);
prep_new_huge_page(h, page, page_to_nid(page));
}
}
@@ -1455,15 +1501,15 @@ int hugetlb_overcommit_handler(struct ctl_table *table, int write,
#endif /* CONFIG_SYSCTL */
-int hugetlb_report_meminfo(char *buf)
+void hugetlb_report_meminfo(struct seq_file *m)
{
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",
+ seq_printf(m,
+ "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 +1793,8 @@ 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 +2117,14 @@ 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 +2134,8 @@ 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 +2148,11 @@ 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 +2172,11 @@ 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] = mem_map_offset(page, pfn_offset);
+ get_page(pages[i]);
}
if (vmas)
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