1 files changed, 50 insertions, 22 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 67a71191136e..421aee99b84a 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)
@@ -1455,15 +1456,15 @@ 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 +1748,8 @@ 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;
@@ -2008,7 +2007,7 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
         entry = huge_ptep_get(ptep);
         if (huge_pte_none(entry)) {
                 ret = hugetlb_no_page(mm, vma, address, ptep, write_access);
-                goto out_unlock;
+                goto out_mutex;
         }
 
         ret = 0;
@@ -2024,7 +2023,7 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
         if (write_access && !pte_write(entry)) {
                 if (vma_needs_reservation(h, vma, address) < 0) {
                         ret = VM_FAULT_OOM;
-                        goto out_unlock;
+                        goto out_mutex;
                 }
 
                 if (!(vma->vm_flags & VM_SHARED))
@@ -2034,10 +2033,23 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 
         spin_lock(&mm->page_table_lock);
         /* Check for a racing update before calling hugetlb_cow */
-        if (likely(pte_same(entry, huge_ptep_get(ptep))))
-                if (write_access && !pte_write(entry))
+        if (unlikely(!pte_same(entry, huge_ptep_get(ptep))))
+                goto out_page_table_lock;
+
+
+        if (write_access) {
+                if (!pte_write(entry)) {
                         ret = hugetlb_cow(mm, vma, address, ptep, entry,
                                                         pagecache_page);
+                        goto out_page_table_lock;
+                }
+                entry = pte_mkdirty(entry);
+        }
+        entry = pte_mkyoung(entry);
+        if (huge_ptep_set_access_flags(vma, address, ptep, entry, write_access))
+                update_mmu_cache(vma, address, entry);
+
+out_page_table_lock:
         spin_unlock(&mm->page_table_lock);
 
         if (pagecache_page) {
@@ -2045,7 +2057,7 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
                 put_page(pagecache_page);
         }
 
-out_unlock:
+out_mutex:
         mutex_unlock(&hugetlb_instantiation_mutex);
 
         return ret;
@@ -2060,6 +2072,14 @@ 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,
@@ -2069,6 +2089,8 @@ 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) {
@@ -2081,8 +2103,11 @@ 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;
 
@@ -2102,8 +2127,11 @@ 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)