mm, rmap: account shmem thp pages

Let's add ShmemHugePages and ShmemPmdMapped fields into meminfo and
smaps.  It indicates how many times we allocate and map shmem THP.

NR_ANON_TRANSPARENT_HUGEPAGES is renamed to NR_ANON_THPS.

Link: http://lkml.kernel.org/r/1466021202-61880-27-git-send-email-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 32 insertions, 7 deletions

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 3b74fea6b5db..6c524984931b 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -3067,7 +3067,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
 
 	if (atomic_add_negative(-1, compound_mapcount_ptr(page))) {
 		/* Last compound_mapcount is gone. */
-		__dec_zone_page_state(page, NR_ANON_TRANSPARENT_HUGEPAGES);
+		__dec_zone_page_state(page, NR_ANON_THPS);
 		if (TestClearPageDoubleMap(page)) {
 			/* No need in mapcount reference anymore */
 			for (i = 0; i < HPAGE_PMD_NR; i++)
@@ -3539,6 +3539,8 @@ int split_huge_page_to_list(struct page *page, struct list_head *list)
 			pgdata->split_queue_len--;
 			list_del(page_deferred_list(head));
 		}
+		if (mapping)
+			__dec_zone_page_state(page, NR_SHMEM_THPS);
 		spin_unlock(&pgdata->split_queue_lock);
 		__split_huge_page(page, list, flags);
 		ret = 0;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 847281eb74da..452513bf02ce 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4312,6 +4312,9 @@ void show_free_areas(unsigned int filter)
 		" unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
 		" slab_reclaimable:%lu slab_unreclaimable:%lu\n"
 		" mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+		" anon_thp: %lu shmem_thp: %lu shmem_pmdmapped: %lu\n"
+#endif
 		" free:%lu free_pcp:%lu free_cma:%lu\n",
 		global_page_state(NR_ACTIVE_ANON),
 		global_page_state(NR_INACTIVE_ANON),
@@ -4329,6 +4332,11 @@ void show_free_areas(unsigned int filter)
 		global_page_state(NR_SHMEM),
 		global_page_state(NR_PAGETABLE),
 		global_page_state(NR_BOUNCE),
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+		global_page_state(NR_ANON_THPS) * HPAGE_PMD_NR,
+		global_page_state(NR_SHMEM_THPS) * HPAGE_PMD_NR,
+		global_page_state(NR_SHMEM_PMDMAPPED) * HPAGE_PMD_NR,
+#endif
 		global_page_state(NR_FREE_PAGES),
 		free_pcp,
 		global_page_state(NR_FREE_CMA_PAGES));
@@ -4363,6 +4371,11 @@ void show_free_areas(unsigned int filter)
 			" writeback:%lukB"
 			" mapped:%lukB"
 			" shmem:%lukB"
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+			" shmem_thp: %lukB"
+			" shmem_pmdmapped: %lukB"
+			" anon_thp: %lukB"
+#endif
 			" slab_reclaimable:%lukB"
 			" slab_unreclaimable:%lukB"
 			" kernel_stack:%lukB"
@@ -4395,6 +4408,12 @@ void show_free_areas(unsigned int filter)
 			K(zone_page_state(zone, NR_WRITEBACK)),
 			K(zone_page_state(zone, NR_FILE_MAPPED)),
 			K(zone_page_state(zone, NR_SHMEM)),
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+			K(zone_page_state(zone, NR_SHMEM_THPS) * HPAGE_PMD_NR),
+			K(zone_page_state(zone, NR_SHMEM_PMDMAPPED)
+					* HPAGE_PMD_NR),
+			K(zone_page_state(zone, NR_ANON_THPS) * HPAGE_PMD_NR),
+#endif
 			K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
 			K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
 			zone_page_state(zone, NR_KERNEL_STACK) *
diff --git a/mm/rmap.c b/mm/rmap.c
index 9d643b7a99ce..8a13d9f7b566 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1212,10 +1212,8 @@ void do_page_add_anon_rmap(struct page *page,
 		 * pte lock(a spinlock) is held, which implies preemption
 		 * disabled.
 		 */
-		if (compound) {
-			__inc_zone_page_state(page,
-					      NR_ANON_TRANSPARENT_HUGEPAGES);
-		}
+		if (compound)
+			__inc_zone_page_state(page, NR_ANON_THPS);
 		__mod_zone_page_state(page_zone(page), NR_ANON_PAGES, nr);
 	}
 	if (unlikely(PageKsm(page)))
@@ -1253,7 +1251,7 @@ void page_add_new_anon_rmap(struct page *page,
 		VM_BUG_ON_PAGE(!PageTransHuge(page), page);
 		/* increment count (starts at -1) */
 		atomic_set(compound_mapcount_ptr(page), 0);
-		__inc_zone_page_state(page, NR_ANON_TRANSPARENT_HUGEPAGES);
+		__inc_zone_page_state(page, NR_ANON_THPS);
 	} else {
 		/* Anon THP always mapped first with PMD */
 		VM_BUG_ON_PAGE(PageTransCompound(page), page);
@@ -1283,6 +1281,8 @@ void page_add_file_rmap(struct page *page, bool compound)
 		}
 		if (!atomic_inc_and_test(compound_mapcount_ptr(page)))
 			goto out;
+		VM_BUG_ON_PAGE(!PageSwapBacked(page), page);
+		__inc_zone_page_state(page, NR_SHMEM_PMDMAPPED);
 	} else {
 		if (PageTransCompound(page)) {
 			VM_BUG_ON_PAGE(!PageLocked(page), page);
@@ -1321,6 +1321,8 @@ static void page_remove_file_rmap(struct page *page, bool compound)
 		}
 		if (!atomic_add_negative(-1, compound_mapcount_ptr(page)))
 			goto out;
+		VM_BUG_ON_PAGE(!PageSwapBacked(page), page);
+		__dec_zone_page_state(page, NR_SHMEM_PMDMAPPED);
 	} else {
 		if (!atomic_add_negative(-1, &page->_mapcount))
 			goto out;
@@ -1354,7 +1356,7 @@ static void page_remove_anon_compound_rmap(struct page *page)
 	if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))
 		return;
 
-	__dec_zone_page_state(page, NR_ANON_TRANSPARENT_HUGEPAGES);
+	__dec_zone_page_state(page, NR_ANON_THPS);
 
 	if (TestClearPageDoubleMap(page)) {
 		/*
diff --git a/mm/vmstat.c b/mm/vmstat.c
index cff2f4ec9cce..7997f52935c9 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -733,6 +733,8 @@ const char * const vmstat_text[] = {
 	"workingset_activate",
 	"workingset_nodereclaim",
 	"nr_anon_transparent_hugepages",
+	"nr_shmem_hugepages",
+	"nr_shmem_pmdmapped",
 	"nr_free_cma",
 
 	/* enum writeback_stat_item counters */