[v3 PATCH 9/9] mm: numa: add page promotion counter

[Yang Shi]

Add counter for page promotion for NUMA balancing.

Signed-off-by: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
---
 include/linux/vm_event_item.h | 1 +
 mm/huge_memory.c              | 4 ++++
 mm/memory.c                   | 4 ++++
 mm/vmstat.c                   | 1 +
 4 files changed, 10 insertions(+)

diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h
index 499a3aa..9f52a62 100644
--- a/include/linux/vm_event_item.h
+++ b/include/linux/vm_event_item.h
@@ -51,6 +51,7 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
 		NUMA_HINT_FAULTS,
 		NUMA_HINT_FAULTS_LOCAL,
 		NUMA_PAGE_MIGRATE,
+		NUMA_PAGE_PROMOTE,
 #endif
 #ifdef CONFIG_MIGRATION
 		PGMIGRATE_SUCCESS, PGMIGRATE_FAIL,
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 9f8bce9..01cfe29 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1638,6 +1638,10 @@ vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t pmd)
 	migrated = migrate_misplaced_transhuge_page(vma->vm_mm, vma,
 				vmf->pmd, pmd, vmf->address, page, target_nid);
 	if (migrated) {
+		if (!node_state(page_nid, N_CPU_MEM) &&
+		    node_state(target_nid, N_CPU_MEM))
+			count_vm_numa_events(NUMA_PAGE_PROMOTE, HPAGE_PMD_NR);
+
 		flags |= TNF_MIGRATED;
 		page_nid = target_nid;
 	} else
diff --git a/mm/memory.c b/mm/memory.c
index 96f1d47..e554cd5 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3770,6 +3770,10 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf)
 	/* Migrate to the requested node */
 	migrated = migrate_misplaced_page(page, vma, target_nid);
 	if (migrated) {
+		if (!node_state(page_nid, N_CPU_MEM) &&
+		    node_state(target_nid, N_CPU_MEM))
+			count_vm_numa_event(NUMA_PAGE_PROMOTE);
+
 		page_nid = target_nid;
 		flags |= TNF_MIGRATED;
 	} else
diff --git a/mm/vmstat.c b/mm/vmstat.c
index eee29a9..0140736 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1220,6 +1220,7 @@ int fragmentation_index(struct zone *zone, unsigned int order)
 	"numa_hint_faults",
 	"numa_hint_faults_local",
 	"numa_pages_migrated",
+	"numa_pages_promoted",
 #endif
 #ifdef CONFIG_MIGRATION
 	"pgmigrate_success",
-- 
1.8.3.1