linux-4.4.1/__split_huge_page() の履歴(No.1)

• 履歴一覧
• 差分 を表示
• 現在との差分 を表示
• ソース を表示
• linux-4.4.1/__split_huge_page() へ行く。
  • 1 (2017-09-20 (水) 10:13:18)

参照元†

• linux-4.4.1/split_huge_page_to_list()

説明†

• パス: [[linux-4.4.1/]]

• FIXME: これは何？
  • 説明

引数†

• struct page *page
  • linux-4.4.1/page
• struct anon_vma *anon_vma
  • linux-4.4.1/anon_vma
• struct list_head *list
  • linux-4.4.1/list_head

返り値†

• void

参考†

実装†

/* must be called with anon_vma->root->rwsem held */
static void __split_huge_page(struct page *page,
			      struct anon_vma *anon_vma,
			      struct list_head *list)
{
	int mapcount, mapcount2;
	pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
	struct anon_vma_chain *avc;

• • linux-4.4.1/pgoff_t
  • linux-4.4.1/anon_vma_chain

	BUG_ON(!PageHead(page));
	BUG_ON(PageTail(page));

• • linux-4.4.1/BUG_ON()
  • linux-4.4.1/PageHead()
  • linux-4.4.1/PageTail()

	mapcount = 0;
	anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, pgoff, pgoff) {
		struct vm_area_struct *vma = avc->vma;
		unsigned long addr = vma_address(page, vma);
		BUG_ON(is_vma_temporary_stack(vma));
		mapcount += __split_huge_page_splitting(page, vma, addr);
	}

• • linux-4.4.1/anon_vma_interval_tree_foreach()
  • linux-4.4.1/vm_area_struct
  • linux-4.4.1/vma_address()
  • linux-4.4.1/BUG_ON()
  • linux-4.4.1/is_vma_temporary_stack()
  • linux-4.4.1/__split_huge_page_splitting()

	/*
	 * It is critical that new vmas are added to the tail of the
	 * anon_vma list. This guarantes that if copy_huge_pmd() runs
	 * and establishes a child pmd before
	 * __split_huge_page_splitting() freezes the parent pmd (so if
	 * we fail to prevent copy_huge_pmd() from running until the
	 * whole __split_huge_page() is complete), we will still see
	 * the newly established pmd of the child later during the
	 * walk, to be able to set it as pmd_trans_splitting too.
	 */
	if (mapcount != page_mapcount(page)) {
		pr_err("mapcount %d page_mapcount %d\n",
			mapcount, page_mapcount(page));
		BUG();
	}

• • linux-4.4.1/page_mapcount()
  • linux-4.4.1/pr_err()
  • linux-4.4.1/BUG()

	__split_huge_page_refcount(page, list);

• • linux-4.4.1/__split_huge_page_refcount()

	mapcount2 = 0;
	anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, pgoff, pgoff) {
		struct vm_area_struct *vma = avc->vma;
		unsigned long addr = vma_address(page, vma);
		BUG_ON(is_vma_temporary_stack(vma));
		mapcount2 += __split_huge_page_map(page, vma, addr);
	}

• • linux-4.4.1/anon_vma_interval_tree_foreach()
  • linux-4.4.1/vm_area_struct
  • linux-4.4.1/vma_address()
  • linux-4.4.1/BUG_ON()
  • linux-4.4.1/is_vma_temporary_stack()
  • linux-4.4.1/__split_huge_page_map()

	if (mapcount != mapcount2) {
		pr_err("mapcount %d mapcount2 %d page_mapcount %d\n",
			mapcount, mapcount2, page_mapcount(page));
		BUG();
	}
}

コメント†