thp: clear_copy_huge_page

[linux-2.6-block.git] / mm / memory.c

diff --git a/mm/memory.c b/mm/memory.c
index 567bca80ea539e410e271527264d2bdc014f1e7e..60e1c68d821845f4bf75fe23e8d070ccc80eb360 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3645,3 +3645,74 @@ void might_fault(void)
 }
 EXPORT_SYMBOL(might_fault);
 #endif
+
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS)
+static void clear_gigantic_page(struct page *page,
+                               unsigned long addr,
+                               unsigned int pages_per_huge_page)
+{
+       int i;
+       struct page *p = page;
+
+       might_sleep();
+       for (i = 0; i < pages_per_huge_page;
+            i++, p = mem_map_next(p, page, i)) {
+               cond_resched();
+               clear_user_highpage(p, addr + i * PAGE_SIZE);
+       }
+}
+void clear_huge_page(struct page *page,
+                    unsigned long addr, unsigned int pages_per_huge_page)
+{
+       int i;
+
+       if (unlikely(pages_per_huge_page > MAX_ORDER_NR_PAGES)) {
+               clear_gigantic_page(page, addr, pages_per_huge_page);
+               return;
+       }
+
+       might_sleep();
+       for (i = 0; i < pages_per_huge_page; i++) {
+               cond_resched();
+               clear_user_highpage(page + i, addr + i * PAGE_SIZE);
+       }
+}
+
+static void copy_user_gigantic_page(struct page *dst, struct page *src,
+                                   unsigned long addr,
+                                   struct vm_area_struct *vma,
+                                   unsigned int pages_per_huge_page)
+{
+       int i;
+       struct page *dst_base = dst;
+       struct page *src_base = src;
+
+       for (i = 0; i < pages_per_huge_page; ) {
+               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);
+       }
+}
+
+void copy_user_huge_page(struct page *dst, struct page *src,
+                        unsigned long addr, struct vm_area_struct *vma,
+                        unsigned int pages_per_huge_page)
+{
+       int i;
+
+       if (unlikely(pages_per_huge_page > MAX_ORDER_NR_PAGES)) {
+               copy_user_gigantic_page(dst, src, addr, vma,
+                                       pages_per_huge_page);
+               return;
+       }
+
+       might_sleep();
+       for (i = 0; i < pages_per_huge_page; i++) {
+               cond_resched();
+               copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma);
+       }
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */