linux-4.4.1/split_huge_page_to_list() 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_to_list() へ行く。
  • 1 (2017-09-20 (水) 10:17:30)

参照元†

• linux-4.4.1/split_huge_page()

説明†

• パス: linux-4.4.1/mm/huge_memory.c

• FIXME: これは何？
  • 説明

引数†

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

返り値†

• int

参考†

実装†

/*
 * Split a hugepage into normal pages. This doesn't change the position of head
 * page. If @list is null, tail pages will be added to LRU list, otherwise, to
 * @list. Both head page and tail pages will inherit mapping, flags, and so on
 * from the hugepage.
 * Return 0 if the hugepage is split successfully otherwise return 1.
 */
int split_huge_page_to_list(struct page *page, struct list_head *list)
{
	struct anon_vma *anon_vma;
	int ret = 1;

• • linux-4.4.1/anon_vma

	BUG_ON(is_huge_zero_page(page));
	BUG_ON(!PageAnon(page));

• • linux-4.4.1/BUG_ON()
  • linux-4.4.1/is_huge_zero_page()
  • linux-4.4.1/PageAnon()

	/*
	 * The caller does not necessarily hold an mmap_sem that would prevent
	 * the anon_vma disappearing so we first we take a reference to it
	 * and then lock the anon_vma for write. This is similar to
	 * page_lock_anon_vma_read except the write lock is taken to serialise
	 * against parallel split or collapse operations.
	 */
	anon_vma = page_get_anon_vma(page);
	if (!anon_vma)
		goto out;
	anon_vma_lock_write(anon_vma);

• • linux-4.4.1/page_get_anon_vma()
  • linux-4.4.1/anon_vma_lock_write()

	ret = 0;
	if (!PageCompound(page))
		goto out_unlock;

• • linux-4.4.1/PageCompound()

	BUG_ON(!PageSwapBacked(page));
	__split_huge_page(page, anon_vma, list);
	count_vm_event(THP_SPLIT);

• • linux-4.4.1/BUG_ON()
  • linux-4.4.1/PageSwapBacked()
  • linux-4.4.1/__split_huge_page()
  • linux-4.4.1/count_vm_event()

	BUG_ON(PageCompound(page));

• • linux-4.4.1/PageCompound()

out_unlock:
	anon_vma_unlock_write(anon_vma);
	put_anon_vma(anon_vma);

• • linux-4.4.1/anon_vma_unlock_write()
  • linux-4.4.1/put_anon_vma()

out:
	return ret;
}

コメント†