mm: move lruvec stats update functions to vmstat.h

Patch series "memcg: add pagetable comsumption to memory.stat", v2.

Many workloads consumes significant amount of memory in pagetables.  One
specific use-case is the user space network driver which mmaps the
application memory to provide zero copy transfer.  This driver can consume
a large amount memory in page tables.  This patch series exposes the
pagetable comsumption for each memory cgroup.

This patch (of 2):

This does not change any functionality and only move the functions which
update the lruvec stats to vmstat.h from memcontrol.h.  The main reason
for this patch is to be able to use these functions in the page table
contructor function which is defined in mm.h and we can not include the
memcontrol.h in that file.  Also this is a better place for this interface
in general.  The lruvec abstraction, while invented for memcg, isn't
specific to memcg at all.

Link: https://lkml.kernel.org/r/20201130212541.2781790-2-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 17 insertions, 0 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 0083b69b5cac..52837d68bbec 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -853,6 +853,23 @@ 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,
+			     int val)
+{
+	struct page *head = compound_head(page); /* rmap on tail pages */
+	pg_data_t *pgdat = page_pgdat(page);
+	struct lruvec *lruvec;
+
+	/* Untracked pages have no memcg, no lruvec. Update only the node */
+	if (!head->mem_cgroup) {
+		__mod_node_page_state(pgdat, idx, val);
+		return;
+	}
+
+	lruvec = mem_cgroup_lruvec(head->mem_cgroup, pgdat);
+	__mod_lruvec_state(lruvec, idx, val);
+}
+
 void __mod_lruvec_kmem_state(void *p, enum node_stat_item idx, int val)
 {
 	pg_data_t *pgdat = page_pgdat(virt_to_page(p));