mm/memcontrol: remove __mod_lruvec_page_state()

There are no more callers of __mod_lruvec_page_state(), so convert the
implementation to __lruvec_stat_mod_folio(), removing two calls to
compound_head() (one explicit, one hidden inside page_memcg()).

Link: https://lkml.kernel.org/r/20231228085748.1083901-7-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: Matthew Wilcox (Oracle)

include/linux/vmstat.h

@@ -556,19 +556,25 @@ static inline void mod_lruvec_state(struct lruvec *lruvec,
 	local_irq_restore(flags);
 }
 
-void __mod_lruvec_page_state(struct page *page,
+void __lruvec_stat_mod_folio(struct folio *folio,
 			     enum node_stat_item idx, int val);
 
-static inline void mod_lruvec_page_state(struct page *page,
+static inline void lruvec_stat_mod_folio(struct folio *folio,
 					 enum node_stat_item idx, int val)
 {
 	unsigned long flags;
 
 	local_irq_save(flags);
-	__mod_lruvec_page_state(page, idx, val);
+	__lruvec_stat_mod_folio(folio, idx, val);
 	local_irq_restore(flags);
 }
 
+static inline void mod_lruvec_page_state(struct page *page,
+					 enum node_stat_item idx, int val)
+{
+	lruvec_stat_mod_folio(page_folio(page), idx, val);
+}
+
 #else
 
 static inline void __mod_lruvec_state(struct lruvec *lruvec,
@@ -583,10 +589,16 @@ static inline void mod_lruvec_state(struct lruvec *lruvec,
 	mod_node_page_state(lruvec_pgdat(lruvec), idx, val);
 }
 
-static inline void __mod_lruvec_page_state(struct page *page,
-					   enum node_stat_item idx, int val)
+static inline void __lruvec_stat_mod_folio(struct folio *folio,
+					 enum node_stat_item idx, int val)
 {
-	__mod_node_page_state(page_pgdat(page), idx, val);
+	__mod_node_page_state(folio_pgdat(folio), idx, val);
+}
+
+static inline void lruvec_stat_mod_folio(struct folio *folio,
+					 enum node_stat_item idx, int val)
+{
+	mod_node_page_state(folio_pgdat(folio), idx, val);
 }
 
 static inline void mod_lruvec_page_state(struct page *page,
@@ -597,12 +609,6 @@ static inline void mod_lruvec_page_state(struct page *page,
 
 #endif /* CONFIG_MEMCG */
 
-static inline void __lruvec_stat_mod_folio(struct folio *folio,
-					   enum node_stat_item idx, int val)
-{
-	__mod_lruvec_page_state(&folio->page, idx, val);
-}
-
 static inline void __lruvec_stat_add_folio(struct folio *folio,
 					   enum node_stat_item idx)
 {
@@ -615,12 +621,6 @@ static inline void __lruvec_stat_sub_folio(struct folio *folio,
 	__lruvec_stat_mod_folio(folio, idx, -folio_nr_pages(folio));
 }
 
-static inline void lruvec_stat_mod_folio(struct folio *folio,
-					 enum node_stat_item idx, int val)
-{
-	mod_lruvec_page_state(&folio->page, idx, val);
-}
-
 static inline void lruvec_stat_add_folio(struct folio *folio,
 					 enum node_stat_item idx)
 {

mm/memcontrol.c

@@ -890,16 +890,15 @@ void __mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
 		__mod_memcg_lruvec_state(lruvec, idx, val);
 }
 
-void __mod_lruvec_page_state(struct page *page, enum node_stat_item idx,
+void __lruvec_stat_mod_folio(struct folio *folio, enum node_stat_item idx,
 			     int val)
 {
-	struct page *head = compound_head(page); /* rmap on tail pages */
 	struct mem_cgroup *memcg;
-	pg_data_t *pgdat = page_pgdat(page);
+	pg_data_t *pgdat = folio_pgdat(folio);
 	struct lruvec *lruvec;
 
 	rcu_read_lock();
-	memcg = page_memcg(head);
+	memcg = folio_memcg(folio);
 	/* Untracked pages have no memcg, no lruvec. Update only the node */
 	if (!memcg) {
 		rcu_read_unlock();
@@ -911,7 +910,7 @@ void __mod_lruvec_page_state(struct page *page, enum node_stat_item idx,
 	__mod_lruvec_state(lruvec, idx, val);
 	rcu_read_unlock();
 }
-EXPORT_SYMBOL(__mod_lruvec_page_state);
+EXPORT_SYMBOL(__lruvec_stat_mod_folio);
 
 void __mod_lruvec_kmem_state(void *p, enum node_stat_item idx, int val)
 {