[RFC PATCH 12/26] mm: page_alloc: per-migratetype free counts

[Johannes Weiner]

Increase visibility into the defragmentation behavior by tracking and
reporting per-migratetype free counters.

Subsequent patches will also use those counters to make more targeted
reclaim/compaction decisions.

Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
---
 include/linux/mmzone.h |  5 +++++
 mm/page_alloc.c        | 29 +++++++++++++++++++++++++----
 mm/vmstat.c            |  5 +++++
 3 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 20542e5a0a43..d1083ab81998 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -139,6 +139,11 @@ enum numa_stat_item {
 enum zone_stat_item {
 	/* First 128 byte cacheline (assuming 64 bit words) */
 	NR_FREE_PAGES,
+	NR_FREE_UNMOVABLE,
+	NR_FREE_MOVABLE,
+	NR_FREE_RECLAIMABLE,
+	NR_FREE_HIGHATOMIC,
+	NR_FREE_FREE,
 	NR_ZONE_LRU_BASE, /* Used only for compaction and reclaim retry */
 	NR_ZONE_INACTIVE_ANON = NR_ZONE_LRU_BASE,
 	NR_ZONE_ACTIVE_ANON,
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 44da23625f51..5f2a0037bed1 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -959,8 +959,12 @@ static inline void account_freepages(struct page *page, struct zone *zone,
 
 	__mod_zone_page_state(zone, NR_FREE_PAGES, nr_pages);
 
-	if (is_migrate_cma(migratetype))
+	if (migratetype <= MIGRATE_FREE)
+		__mod_zone_page_state(zone, NR_FREE_UNMOVABLE + migratetype, nr_pages);
+	else if (is_migrate_cma(migratetype))
 		__mod_zone_page_state(zone, NR_FREE_CMA_PAGES, nr_pages);
+	else
+		VM_WARN_ONCE(1, "unexpected migratetype %d\n", migratetype);
 }
 
 /* Used for pages not on another list */
@@ -6175,7 +6179,9 @@ void __show_free_areas(unsigned int filter, nodemask_t *nodemask, int max_zone_i
 		" mapped:%lu shmem:%lu pagetables:%lu\n"
 		" sec_pagetables:%lu bounce:%lu\n"
 		" kernel_misc_reclaimable:%lu\n"
-		" free:%lu free_pcp:%lu free_cma:%lu\n",
+		" free:%lu free_unmovable:%lu free_movable:%lu\n"
+		" free_reclaimable:%lu free_highatomic:%lu free_free:%lu\n"
+		" free_cma:%lu free_pcp:%lu\n",
 		global_node_page_state(NR_ACTIVE_ANON),
 		global_node_page_state(NR_INACTIVE_ANON),
 		global_node_page_state(NR_ISOLATED_ANON),
@@ -6194,8 +6200,13 @@ void __show_free_areas(unsigned int filter, nodemask_t *nodemask, int max_zone_i
 		global_zone_page_state(NR_BOUNCE),
 		global_node_page_state(NR_KERNEL_MISC_RECLAIMABLE),
 		global_zone_page_state(NR_FREE_PAGES),
-		free_pcp,
-		global_zone_page_state(NR_FREE_CMA_PAGES));
+		global_zone_page_state(NR_FREE_UNMOVABLE),
+		global_zone_page_state(NR_FREE_MOVABLE),
+		global_zone_page_state(NR_FREE_RECLAIMABLE),
+		global_zone_page_state(NR_FREE_HIGHATOMIC),
+		global_zone_page_state(NR_FREE_FREE),
+		global_zone_page_state(NR_FREE_CMA_PAGES),
+		free_pcp);
 
 	for_each_online_pgdat(pgdat) {
 		if (show_mem_node_skip(filter, pgdat->node_id, nodemask))
@@ -6273,6 +6284,11 @@ void __show_free_areas(unsigned int filter, nodemask_t *nodemask, int max_zone_i
 		printk(KERN_CONT
 			"%s"
 			" free:%lukB"
+			" free_unmovable:%lukB"
+			" free_movable:%lukB"
+			" free_reclaimable:%lukB"
+			" free_highatomic:%lukB"
+			" free_free:%lukB"
 			" boost:%lukB"
 			" min:%lukB"
 			" low:%lukB"
@@ -6294,6 +6310,11 @@ void __show_free_areas(unsigned int filter, nodemask_t *nodemask, int max_zone_i
 			"\n",
 			zone->name,
 			K(zone_page_state(zone, NR_FREE_PAGES)),
+			K(zone_page_state(zone, NR_FREE_UNMOVABLE)),
+			K(zone_page_state(zone, NR_FREE_MOVABLE)),
+			K(zone_page_state(zone, NR_FREE_RECLAIMABLE)),
+			K(zone_page_state(zone, NR_FREE_HIGHATOMIC)),
+			K(zone_page_state(zone, NR_FREE_FREE)),
 			K(zone->watermark_boost),
 			K(min_wmark_pages(zone)),
 			K(low_wmark_pages(zone)),
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 1ea6a5ce1c41..c8b8e6e259da 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1168,6 +1168,11 @@ int fragmentation_index(struct zone *zone, unsigned int order)
 const char * const vmstat_text[] = {
 	/* enum zone_stat_item counters */
 	"nr_free_pages",
+	"nr_free_unmovable",
+	"nr_free_movable",
+	"nr_free_reclaimable",
+	"nr_free_highatomic",
+	"nr_free_free",
 	"nr_zone_inactive_anon",
 	"nr_zone_active_anon",
 	"nr_zone_inactive_file",
-- 
2.39.2