linux-kernel - [PATCH 48/75] mm/rmap: Turn page_mlock() into folio

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Date:   Fri,  4 Feb 2022 19:58:25 +0000
From:   "Matthew Wilcox (Oracle)" <willy@...radead.org>
To:     linux-mm@...ck.org
Cc:     "Matthew Wilcox (Oracle)" <willy@...radead.org>,
        linux-kernel@...r.kernel.org
Subject: [PATCH 48/75] mm/rmap: Turn page_mlock() into folio_mlock()

Add back page_mlock() as a wrapper around folio_mlock().  Removes
a few hidden calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@...radead.org>
---
 include/linux/rmap.h |  1 +
 mm/folio-compat.c    |  6 ++++++
 mm/rmap.c            | 31 +++++++++++++++++--------------
 3 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index 00b772cdaaaa..31f3a299ef66 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -261,6 +261,7 @@ int folio_mkclean(struct folio *);
  * the page mlocked.
  */
 void page_mlock(struct page *page);
+void folio_mlock(struct folio *folio);
 
 void remove_migration_ptes(struct page *old, struct page *new, bool locked);
 
diff --git a/mm/folio-compat.c b/mm/folio-compat.c
index 9cb0867d5b38..90f03187a5e3 100644
--- a/mm/folio-compat.c
+++ b/mm/folio-compat.c
@@ -7,6 +7,7 @@
 #include <linux/migrate.h>
 #include <linux/pagemap.h>
 #include <linux/swap.h>
+#include <linux/rmap.h>
 #include "internal.h"
 
 struct address_space *page_mapping(struct page *page)
@@ -174,3 +175,8 @@ void mlock_vma_page(struct page *page)
 {
 	mlock_vma_folio(page_folio(page));
 }
+
+void page_mlock(struct page *page)
+{
+	folio_mlock(page_folio(page));
+}
diff --git a/mm/rmap.c b/mm/rmap.c
index 1cedcfd6105c..a383e25fb196 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -2001,6 +2001,7 @@ void try_to_migrate(struct page *page, enum ttu_flags flags)
 static bool page_mlock_one(struct page *page, struct vm_area_struct *vma,
 				 unsigned long address, void *unused)
 {
+	struct folio *folio = page_folio(page);
 	struct page_vma_mapped_walk pvmw = {
 		.vma = vma,
 		.address = address,
@@ -2024,9 +2025,9 @@ static bool page_mlock_one(struct page *page, struct vm_area_struct *vma,
 			 * nor on an Anon THP (which may still be PTE-mapped
 			 * after DoubleMap was cleared).
 			 */
-			mlock_vma_page(page);
+			mlock_vma_folio(folio);
 			/*
-			 * No need to scan further once the page is marked
+			 * No need to scan further once the folio is marked
 			 * as mlocked.
 			 */
 			page_vma_mapped_walk_done(&pvmw);
@@ -2038,14 +2039,14 @@ static bool page_mlock_one(struct page *page, struct vm_area_struct *vma,
 }
 
 /**
- * page_mlock - try to mlock a page
- * @page: the page to be mlocked
+ * folio_mlock() - Try to mlock a folio.
+ * @folio: The folio to be mlocked.
  *
- * Called from munlock code. Checks all of the VMAs mapping the page and mlocks
- * the page if any are found. The page will be returned with PG_mlocked cleared
- * if it is not mapped by any locked vmas.
+ * Called from munlock code. Checks all of the VMAs mapping the folio
+ * and mlocks the folio if any are found. The folio will be returned
+ * with the mlocked flag clear if it is not mapped by any locked vmas.
  */
-void page_mlock(struct page *page)
+void folio_mlock(struct folio *folio)
 {
 	struct rmap_walk_control rwc = {
 		.rmap_one = page_mlock_one,
@@ -2054,14 +2055,16 @@ void page_mlock(struct page *page)
 
 	};
 
-	VM_BUG_ON_PAGE(!PageLocked(page) || PageLRU(page), page);
-	VM_BUG_ON_PAGE(PageCompound(page) && PageDoubleMap(page), page);
+	VM_BUG_ON_FOLIO(!folio_test_locked(folio) || folio_test_lru(folio),
+			folio);
+	VM_BUG_ON_FOLIO(folio_test_large(folio) && folio_test_double_map(folio),
+			folio);
 
 	/* Anon THP are only marked as mlocked when singly mapped */
-	if (PageTransCompound(page) && PageAnon(page))
+	if (folio_test_large(folio) && folio_test_anon(folio))
 		return;
 
-	rmap_walk(page, &rwc);
+	rmap_walk(&folio->page, &rwc);
 }
 
 #ifdef CONFIG_DEVICE_PRIVATE
@@ -2290,7 +2293,7 @@ static struct anon_vma *rmap_walk_anon_lock(struct page *page,
  * Find all the mappings of a page using the mapping pointer and the vma chains
  * contained in the anon_vma struct it points to.
  *
- * When called from page_mlock(), the mmap_lock of the mm containing the vma
+ * When called from folio_mlock(), the mmap_lock of the mm containing the vma
  * where the page was found will be held for write.  So, we won't recheck
  * vm_flags for that VMA.  That should be OK, because that vma shouldn't be
  * LOCKED.
@@ -2343,7 +2346,7 @@ static void rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc,
  * Find all the mappings of a page using the mapping pointer and the vma chains
  * contained in the address_space struct it points to.
  *
- * When called from page_mlock(), the mmap_lock of the mm containing the vma
+ * When called from folio_mlock(), the mmap_lock of the mm containing the vma
  * where the page was found will be held for write.  So, we won't recheck
  * vm_flags for that VMA.  That should be OK, because that vma shouldn't be
  * LOCKED.
-- 
2.34.1