mm: memcontrol: add file_thp, shmem_thp to memory.stat

As huge page usage in the page cache and for shmem files proliferates in
our production environment, the performance monitoring team has asked for
per-cgroup stats on those pages.

We already track and export anon_thp per cgroup.  We already track file
THP and shmem THP per node, so making them per-cgroup is only a matter of
switching from node to lruvec counters.  All callsites are in places where
the pages are charged and locked, so page->memcg is stable.

[hannes@cmpxchg.org: add documentation]
  Link: https://lkml.kernel.org/r/20201026174029.GC548555@cmpxchg.org

Link: https://lkml.kernel.org/r/20201022151844.489337-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index ec2bb93f7431..42b18d461086 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2710,9 +2710,9 @@ int split_huge_page_to_list(struct page *page, struct list_head *list)
 		spin_unlock(&ds_queue->split_queue_lock);
 		if (mapping) {
 			if (PageSwapBacked(head))
-				__dec_node_page_state(head, NR_SHMEM_THPS);
+				__dec_lruvec_page_state(head, NR_SHMEM_THPS);
 			else
-				__dec_node_page_state(head, NR_FILE_THPS);
+				__dec_lruvec_page_state(head, NR_FILE_THPS);
 		}
 
 		__split_huge_page(page, list, end, flags);