[PATCH 04/19] mm: Change NR_FILE_THPS to account in base pages

["Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>]

With variable sized THPs, we have to account in number of base pages,
not in number of PMD-sized pages.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
 drivers/base/node.c    | 3 +--
 fs/proc/meminfo.c      | 2 +-
 include/linux/mmzone.h | 2 +-
 mm/filemap.c           | 2 +-
 mm/huge_memory.c       | 3 ++-
 mm/khugepaged.c        | 3 ++-
 6 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/base/node.c b/drivers/base/node.c
index 6ffa470e2984..6bcc2e7da775 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -467,8 +467,7 @@ static ssize_t node_read_meminfo(struct device *dev,
 				    HPAGE_PMD_NR),
 			     nid, K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED) *
 				    HPAGE_PMD_NR),
-			     nid, K(node_page_state(pgdat, NR_FILE_THPS) *
-				    HPAGE_PMD_NR),
+			     nid, K(node_page_state(pgdat, NR_FILE_THPS)),
 			     nid, K(node_page_state(pgdat, NR_FILE_PMDMAPPED) *
 				    HPAGE_PMD_NR)
 #endif
diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c
index 887a5532e449..d1ccee90f0e1 100644
--- a/fs/proc/meminfo.c
+++ b/fs/proc/meminfo.c
@@ -135,7 +135,7 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
 	show_val_kb(m, "ShmemPmdMapped: ",
 		    global_node_page_state(NR_SHMEM_PMDMAPPED) * HPAGE_PMD_NR);
 	show_val_kb(m, "FileHugePages:  ",
-		    global_node_page_state(NR_FILE_THPS) * HPAGE_PMD_NR);
+		    global_node_page_state(NR_FILE_THPS));
 	show_val_kb(m, "FilePmdMapped:  ",
 		    global_node_page_state(NR_FILE_PMDMAPPED) * HPAGE_PMD_NR);
 #endif
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index fb3bf696c05e..b0e2c546d5f5 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -193,7 +193,7 @@ enum node_stat_item {
 	NR_SHMEM,		/* shmem pages (included tmpfs/GEM pages) */
 	NR_SHMEM_THPS,
 	NR_SHMEM_PMDMAPPED,
-	NR_FILE_THPS,
+	NR_FILE_THPS,		/* Accounted in base pages */
 	NR_FILE_PMDMAPPED,
 	NR_ANON_THPS,
 	NR_VMSCAN_WRITE,
diff --git a/mm/filemap.c b/mm/filemap.c
index 8537ee86f99f..a68516ddeddc 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -194,7 +194,7 @@ static void unaccount_page_cache_page(struct address_space *mapping,
 		if (PageTransHuge(page))
 			__dec_lruvec_page_state(page, NR_SHMEM_THPS);
 	} else if (PageTransHuge(page)) {
-		__dec_lruvec_page_state(page, NR_FILE_THPS);
+		__mod_lruvec_page_state(page, NR_FILE_THPS, -nr);
 		filemap_nr_thps_dec(mapping);
 	}
 
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 0e900e594e77..03374ec61b45 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2729,7 +2729,8 @@ int split_huge_page_to_list(struct page *page, struct list_head *list)
 			if (PageSwapBacked(head))
 				__dec_lruvec_page_state(head, NR_SHMEM_THPS);
 			else
-				__dec_lruvec_page_state(head, NR_FILE_THPS);
+				__mod_lruvec_page_state(head, NR_FILE_THPS,
+						-thp_nr_pages(head));
 		}
 
 		__split_huge_page(page, list, end, flags);
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 230e62a92ae7..74c90f5d352f 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1844,7 +1844,8 @@ static void collapse_file(struct mm_struct *mm,
 	if (is_shmem)
 		__inc_lruvec_page_state(new_page, NR_SHMEM_THPS);
 	else {
-		__inc_lruvec_page_state(new_page, NR_FILE_THPS);
+		__mod_lruvec_page_state(new_page, NR_FILE_THPS,
+				thp_nr_pages(new_page));
 		filemap_nr_thps_inc(mapping);
 	}
 
-- 
2.28.0