Commit 42a346b4 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Andrew Morton
Browse files

hugetlb: remove mention of destructors 

We no longer have destructors or dtors, merely a page flag (technically a
page type flag, but that's an implementation detail).  Remove
__clear_hugetlb_destructor, fix up comments and the occasional variable
name.

Link: https://lkml.kernel.org/r/20240321142448.1645400-10-willy@infradead.org


Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 8f790d0c

mm/hugetlb.c

+16 −24
Original line number Diff line number Diff line
@@ -1619,19 +1619,11 @@ static inline void destroy_compound_gigantic_folio(struct folio *folio, 
						unsigned int order) { }

#endif



static inline void __clear_hugetlb_destructor(struct hstate *h,

						struct folio *folio)

{

	lockdep_assert_held(&hugetlb_lock);



	__folio_clear_hugetlb(folio);

}



/*

 * Remove hugetlb folio from lists.

 * If vmemmap exists for the folio, update dtor so that the folio appears

 * as just a compound page.  Otherwise, wait until after allocating vmemmap

 * to update dtor.

 * If vmemmap exists for the folio, clear the hugetlb flag so that the

 * folio appears as just a compound page.  Otherwise, wait until after

 * allocating vmemmap to clear the flag.

 *

 * A reference is held on the folio, except in the case of demote.

 *
@@ -1662,12 +1654,12 @@ static void __remove_hugetlb_folio(struct hstate *h, struct folio *folio, 
	}



	/*

	 * We can only clear the hugetlb destructor after allocating vmemmap

	 * We can only clear the hugetlb flag after allocating vmemmap

	 * pages.  Otherwise, someone (memory error handling) may try to write

	 * to tail struct pages.

	 */

	if (!folio_test_hugetlb_vmemmap_optimized(folio))

		__clear_hugetlb_destructor(h, folio);

		__folio_clear_hugetlb(folio);



	 /*

	  * In the case of demote we do not ref count the page as it will soon
@@ -1741,7 +1733,7 @@ static void add_hugetlb_folio(struct hstate *h, struct folio *folio, 
static void __update_and_free_hugetlb_folio(struct hstate *h,

						struct folio *folio)

{

	bool clear_dtor = folio_test_hugetlb_vmemmap_optimized(folio);

	bool clear_flag = folio_test_hugetlb_vmemmap_optimized(folio);



	if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported())

		return;
@@ -1754,11 +1746,11 @@ static void __update_and_free_hugetlb_folio(struct hstate *h, 
		return;



	/*

	 * If folio is not vmemmap optimized (!clear_dtor), then the folio

	 * If folio is not vmemmap optimized (!clear_flag), then the folio

	 * is no longer identified as a hugetlb page.  hugetlb_vmemmap_restore_folio

	 * can only be passed hugetlb pages and will BUG otherwise.

	 */

	if (clear_dtor && hugetlb_vmemmap_restore_folio(h, folio)) {

	if (clear_flag && hugetlb_vmemmap_restore_folio(h, folio)) {

		spin_lock_irq(&hugetlb_lock);

		/*

		 * If we cannot allocate vmemmap pages, just refuse to free the
@@ -1779,11 +1771,11 @@ static void __update_and_free_hugetlb_folio(struct hstate *h, 


	/*

	 * If vmemmap pages were allocated above, then we need to clear the

	 * hugetlb destructor under the hugetlb lock.

	 * hugetlb flag under the hugetlb lock.

	 */

	if (folio_test_hugetlb(folio)) {

		spin_lock_irq(&hugetlb_lock);

		__clear_hugetlb_destructor(h, folio);

		__folio_clear_hugetlb(folio);

		spin_unlock_irq(&hugetlb_lock);

	}
@@ -1885,7 +1877,7 @@ static void bulk_vmemmap_restore_error(struct hstate *h, 
		list_for_each_entry_safe(folio, t_folio, non_hvo_folios, lru) {

			list_del(&folio->lru);

			spin_lock_irq(&hugetlb_lock);

			__clear_hugetlb_destructor(h, folio);

			__folio_clear_hugetlb(folio);

			spin_unlock_irq(&hugetlb_lock);

			update_and_free_hugetlb_folio(h, folio, false);

			cond_resched();
@@ -1910,7 +1902,7 @@ static void bulk_vmemmap_restore_error(struct hstate *h, 
			} else {

				list_del(&folio->lru);

				spin_lock_irq(&hugetlb_lock);

				__clear_hugetlb_destructor(h, folio);

				__folio_clear_hugetlb(folio);

				spin_unlock_irq(&hugetlb_lock);

				update_and_free_hugetlb_folio(h, folio, false);

				cond_resched();
@@ -1943,14 +1935,14 @@ static void update_and_free_pages_bulk(struct hstate *h, 
	 * should only be pages on the non_hvo_folios list.

	 * Do note that the non_hvo_folios list could be empty.

	 * Without HVO enabled, ret will be 0 and there is no need to call

	 * __clear_hugetlb_destructor as this was done previously.

	 * __folio_clear_hugetlb as this was done previously.

	 */

	VM_WARN_ON(!list_empty(folio_list));

	VM_WARN_ON(ret < 0);

	if (!list_empty(&non_hvo_folios) && ret) {

		spin_lock_irq(&hugetlb_lock);

		list_for_each_entry(folio, &non_hvo_folios, lru)

			__clear_hugetlb_destructor(h, folio);

			__folio_clear_hugetlb(folio);

		spin_unlock_irq(&hugetlb_lock);

	}
@@ -1975,7 +1967,7 @@ void free_huge_folio(struct folio *folio) 
{

	/*

	 * Can't pass hstate in here because it is called from the

	 * compound page destructor.

	 * generic mm code.

	 */

	struct hstate *h = folio_hstate(folio);

	int nid = folio_nid(folio);
@@ -2125,7 +2117,7 @@ static bool __prep_compound_gigantic_folio(struct folio *folio, 
			set_compound_head(p, &folio->page);

	}

	__folio_set_head(folio);

	/* we rely on prep_new_hugetlb_folio to set the destructor */

	/* we rely on prep_new_hugetlb_folio to set the hugetlb flag */

	folio_set_order(folio, order);

	atomic_set(&folio->_entire_mapcount, -1);

	atomic_set(&folio->_nr_pages_mapped, 0);