mm/workingset: Convert workingset_activation to take a folio

This function already assumed it was being passed a head page.  No real
change here, except that thp_nr_pages() compiles away on kernels with
THP compiled out while folio_nr_pages() is always present.  Also convert
page_memcg_rcu() to folio_memcg_rcu().

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, 12 insertions, 10 deletions

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 05094eaf1d61..7bd78c13d1fa 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -457,20 +457,22 @@ static inline struct mem_cgroup *page_memcg(struct page *page)
 	return folio_memcg(page_folio(page));
 }
 
-/*
- * page_memcg_rcu - locklessly get the memory cgroup associated with a page
- * @page: a pointer to the page struct
+/**
+ * folio_memcg_rcu - Locklessly get the memory cgroup associated with a folio.
+ * @folio: Pointer to the folio.
  *
- * Returns a pointer to the memory cgroup associated with the page,
- * or NULL. This function assumes that the page is known to have a
+ * This function assumes that the folio is known to have a
  * proper memory cgroup pointer. It's not safe to call this function
- * against some type of pages, e.g. slab pages or ex-slab pages.
+ * against some type of folios, e.g. slab folios or ex-slab folios.
+ *
+ * Return: A pointer to the memory cgroup associated with the folio,
+ * or NULL.
  */
-static inline struct mem_cgroup *page_memcg_rcu(struct page *page)
+static inline struct mem_cgroup *folio_memcg_rcu(struct folio *folio)
 {
-	unsigned long memcg_data = READ_ONCE(page->memcg_data);
+	unsigned long memcg_data = READ_ONCE(folio->memcg_data);
 
-	VM_BUG_ON_PAGE(PageSlab(page), page);
+	VM_BUG_ON_FOLIO(folio_test_slab(folio), folio);
 	WARN_ON_ONCE(!rcu_read_lock_held());
 
 	if (memcg_data & MEMCG_DATA_KMEM) {
@@ -1158,7 +1160,7 @@ static inline struct mem_cgroup *page_memcg(struct page *page)
 	return NULL;
 }
 
-static inline struct mem_cgroup *page_memcg_rcu(struct page *page)
+static inline struct mem_cgroup *folio_memcg_rcu(struct folio *folio)
 {
 	WARN_ON_ONCE(!rcu_read_lock_held());
 	return NULL;