linux-4.4.1/split_huge_page_to_list() の変更点

• 追加された行はこの色です。
• 削除された行はこの色です。
• linux-4.4.1/split_huge_page_to_list() へ行く。
• linux-4.4.1/split_huge_page_to_list() の差分を削除

*参照元 [#p2b56f01]
#backlinks

*説明 [#g0c9d29d]
-パス: [[linux-4.4.1/mm/huge_memory.c]]
-パス: 複数あり
--CONFIG_TRANSPARENT_HUGEPAGE 有効: [[linux-4.4.1/mm/huge_memory.c]]
--CONFIG_TRANSPARENT_HUGEPAGE 無効: [[linux-4.4.1/include/linux/huge_mm.h]]
--[[linux-4.4.1/CONFIG_TRANSPARENT_HUGEPAGE]]

-FIXME: これは何？
--説明


**引数 [#q6cd0621]
-struct page *page
--
--[[linux-4.4.1/page]]
-struct list_head *list
--
--[[linux-4.4.1/list_head]]


**返り値 [#y24da8e9]
-int
--


**参考 [#sda70e93]


*実装 [#u52d8d47]

**CONFIG_TRANSPARENT_HUGEPAGE 有効: linux-4.4.1/mm/huge_memory.c [#i754a956]
 /*
  * 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;
 }


**CONFIG_TRANSPARENT_HUGEPAGE 無効: linux-4.4.1/include/linux/huge_mm.h [#e6ea3553]
 static inline int
 split_huge_page_to_list(struct page *page, struct list_head *list)
 {
 	return 0;
 }


*コメント [#n5bf9d26]