mm/memcg: Add folio_lruvec_lock() and similar functions

These are the folio equivalents of lock_page_lruvec() and similar
functions.  Also convert lruvec_memcg_debug() to take a folio.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>

1 files changed, 49 insertions, 28 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index ea4f879d2771..8dab23a71fc4 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1126,67 +1126,88 @@ int mem_cgroup_scan_tasks(struct mem_cgroup *memcg,
 }
 
 #ifdef CONFIG_DEBUG_VM
-void lruvec_memcg_debug(struct lruvec *lruvec, struct page *page)
+void lruvec_memcg_debug(struct lruvec *lruvec, struct folio *folio)
 {
 	struct mem_cgroup *memcg;
 
 	if (mem_cgroup_disabled())
 		return;
 
-	memcg = page_memcg(page);
+	memcg = folio_memcg(folio);
 
 	if (!memcg)
-		VM_BUG_ON_PAGE(lruvec_memcg(lruvec) != root_mem_cgroup, page);
+		VM_BUG_ON_FOLIO(lruvec_memcg(lruvec) != root_mem_cgroup, folio);
 	else
-		VM_BUG_ON_PAGE(lruvec_memcg(lruvec) != memcg, page);
+		VM_BUG_ON_FOLIO(lruvec_memcg(lruvec) != memcg, folio);
 }
 #endif
 
 /**
- * lock_page_lruvec - lock and return lruvec for a given page.
- * @page: the page
+ * folio_lruvec_lock - Lock the lruvec for a folio.
+ * @folio: Pointer to the folio.
  *
  * These functions are safe to use under any of the following conditions:
- * - page locked
- * - PageLRU cleared
- * - lock_page_memcg()
- * - page->_refcount is zero
+ * - folio locked
+ * - folio_test_lru false
+ * - folio_memcg_lock()
+ * - folio frozen (refcount of 0)
+ *
+ * Return: The lruvec this folio is on with its lock held.
  */
-struct lruvec *lock_page_lruvec(struct page *page)
+struct lruvec *folio_lruvec_lock(struct folio *folio)
 {
-	struct folio *folio = page_folio(page);
-	struct lruvec *lruvec;
+	struct lruvec *lruvec = folio_lruvec(folio);
 
-	lruvec = folio_lruvec(folio);
 	spin_lock(&lruvec->lru_lock);
-
-	lruvec_memcg_debug(lruvec, page);
+	lruvec_memcg_debug(lruvec, folio);
 
 	return lruvec;
 }
 
-struct lruvec *lock_page_lruvec_irq(struct page *page)
+/**
+ * folio_lruvec_lock_irq - Lock the lruvec for a folio.
+ * @folio: Pointer to the folio.
+ *
+ * These functions are safe to use under any of the following conditions:
+ * - folio locked
+ * - folio_test_lru false
+ * - folio_memcg_lock()
+ * - folio frozen (refcount of 0)
+ *
+ * Return: The lruvec this folio is on with its lock held and interrupts
+ * disabled.
+ */
+struct lruvec *folio_lruvec_lock_irq(struct folio *folio)
 {
-	struct folio *folio = page_folio(page);
-	struct lruvec *lruvec;
+	struct lruvec *lruvec = folio_lruvec(folio);
 
-	lruvec = folio_lruvec(folio);
 	spin_lock_irq(&lruvec->lru_lock);
-
-	lruvec_memcg_debug(lruvec, page);
+	lruvec_memcg_debug(lruvec, folio);
 
 	return lruvec;
 }
 
-struct lruvec *lock_page_lruvec_irqsave(struct page *page, unsigned long *flags)
+/**
+ * folio_lruvec_lock_irqsave - Lock the lruvec for a folio.
+ * @folio: Pointer to the folio.
+ * @flags: Pointer to irqsave flags.
+ *
+ * These functions are safe to use under any of the following conditions:
+ * - folio locked
+ * - folio_test_lru false
+ * - folio_memcg_lock()
+ * - folio frozen (refcount of 0)
+ *
+ * Return: The lruvec this folio is on with its lock held and interrupts
+ * disabled.
+ */
+struct lruvec *folio_lruvec_lock_irqsave(struct folio *folio,
+		unsigned long *flags)
 {
-	struct folio *folio = page_folio(page);
-	struct lruvec *lruvec;
+	struct lruvec *lruvec = folio_lruvec(folio);
 
-	lruvec = folio_lruvec(folio);
 	spin_lock_irqsave(&lruvec->lru_lock, *flags);
-
-	lruvec_memcg_debug(lruvec, page);
+	lruvec_memcg_debug(lruvec, folio);
 
 	return lruvec;
 }