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From:   Sidhartha Kumar <sidhartha.kumar@oracle.com>
To:     linux-kernel@vger.kernel.org, linux-mm@kvack.org
Cc:     akpm@linux-foundation.org, songmuchun@bytedance.com,
        mike.kravetz@oracle.com, willy@infradead.org,
        almasrymina@google.com, linmiaohe@huawei.com, hughd@google.com,
        Sidhartha Kumar <sidhartha.kumar@oracle.com>
Subject: [PATCH mm-unstable 05/10] mm/hugetlb: convert update_and_free_page() to folios
Date:   Tue, 15 Nov 2022 13:22:12 -0800
Message-Id: <20221115212217.19539-6-sidhartha.kumar@oracle.com>
In-Reply-To: <20221115212217.19539-1-sidhartha.kumar@oracle.com>
References: <20221115212217.19539-1-sidhartha.kumar@oracle.com>
MIME-Version: 1.0
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Precedence: bulk

Make more progress on converting the free_huge_page() destructor to
operate on folios by converting update_and_free_page() to folios.

Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
---
 mm/hugetlb.c | 30 ++++++++++++++++--------------
 1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 7804ba51a7b8..660ae46e741b 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1469,7 +1469,7 @@ static void __remove_hugetlb_folio(struct hstate *h, struct folio *folio,
 	 * apply.
 	 *
 	 * This handles the case where more than one ref is held when and
-	 * after update_and_free_page is called.
+	 * after update_and_free_hugetlb_folio is called.
 	 *
 	 * In the case of demote we do not ref count the page as it will soon
 	 * be turned into a page of smaller size.
@@ -1600,7 +1600,7 @@ static void __update_and_free_page(struct hstate *h, struct page *page)
 }
 
 /*
- * As update_and_free_page() can be called under any context, so we cannot
+ * As update_and_free_hugetlb_folio() can be called under any context, so we cannot
  * use GFP_KERNEL to allocate vmemmap pages. However, we can defer the
  * actual freeing in a workqueue to prevent from using GFP_ATOMIC to allocate
  * the vmemmap pages.
@@ -1648,11 +1648,11 @@ static inline void flush_free_hpage_work(struct hstate *h)
 		flush_work(&free_hpage_work);
 }
 
-static void update_and_free_page(struct hstate *h, struct page *page,
+static void update_and_free_hugetlb_folio(struct hstate *h, struct folio *folio,
 				 bool atomic)
 {
-	if (!HPageVmemmapOptimized(page) || !atomic) {
-		__update_and_free_page(h, page);
+	if (!folio_test_hugetlb_vmemmap_optimized(folio) || !atomic) {
+		__update_and_free_page(h, &folio->page);
 		return;
 	}
 
@@ -1663,16 +1663,18 @@ static void update_and_free_page(struct hstate *h, struct page *page,
 	 * empty. Otherwise, schedule_work() had been called but the workfn
 	 * hasn't retrieved the list yet.
 	 */
-	if (llist_add((struct llist_node *)&page->mapping, &hpage_freelist))
+	if (llist_add((struct llist_node *)&folio->mapping, &hpage_freelist))
 		schedule_work(&free_hpage_work);
 }
 
 static void update_and_free_pages_bulk(struct hstate *h, struct list_head *list)
 {
 	struct page *page, *t_page;
+	struct folio *folio;
 
 	list_for_each_entry_safe(page, t_page, list, lru) {
-		update_and_free_page(h, page, false);
+		folio = page_folio(page);
+		update_and_free_hugetlb_folio(h, folio, false);
 		cond_resched();
 	}
 }
@@ -1742,12 +1744,12 @@ void free_huge_page(struct page *page)
 	if (folio_test_hugetlb_temporary(folio)) {
 		remove_hugetlb_folio(h, folio, false);
 		spin_unlock_irqrestore(&hugetlb_lock, flags);
-		update_and_free_page(h, page, true);
+		update_and_free_hugetlb_folio(h, folio, true);
 	} else if (h->surplus_huge_pages_node[nid]) {
 		/* remove the page from active list */
 		remove_hugetlb_folio(h, folio, true);
 		spin_unlock_irqrestore(&hugetlb_lock, flags);
-		update_and_free_page(h, page, true);
+		update_and_free_hugetlb_folio(h, folio, true);
 	} else {
 		arch_clear_hugepage_flags(page);
 		enqueue_huge_page(h, page);
@@ -2160,8 +2162,8 @@ int dissolve_free_huge_page(struct page *page)
 		spin_unlock_irq(&hugetlb_lock);
 
 		/*
-		 * Normally update_and_free_page will allocate required vmemmmap
-		 * before freeing the page.  update_and_free_page will fail to
+		 * Normally update_and_free_hugtlb_folio will allocate required vmemmmap
+		 * before freeing the page.  update_and_free_hugtlb_folio will fail to
 		 * free the page if it can not allocate required vmemmap.  We
 		 * need to adjust max_huge_pages if the page is not freed.
 		 * Attempt to allocate vmemmmap here so that we can take
@@ -2169,7 +2171,7 @@ int dissolve_free_huge_page(struct page *page)
 		 */
 		rc = hugetlb_vmemmap_restore(h, &folio->page);
 		if (!rc) {
-			update_and_free_page(h, &folio->page, false);
+			update_and_free_hugetlb_folio(h, folio, false);
 		} else {
 			spin_lock_irq(&hugetlb_lock);
 			add_hugetlb_page(h, &folio->page, false);
@@ -2807,7 +2809,7 @@ static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page,
 		 * Pages have been replaced, we can safely free the old one.
 		 */
 		spin_unlock_irq(&hugetlb_lock);
-		update_and_free_page(h, old_page, false);
+		update_and_free_hugetlb_folio(h, old_folio, false);
 	}
 
 	return ret;
@@ -2816,7 +2818,7 @@ static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page,
 	spin_unlock_irq(&hugetlb_lock);
 	/* Page has a zero ref count, but needs a ref to be freed */
 	folio_ref_unfreeze(new_folio, 1);
-	update_and_free_page(h, new_page, false);
+	update_and_free_hugetlb_folio(h, new_folio, false);
 
 	return ret;
 }
-- 
2.38.1