[PATCH] mm/vmstats: add thp_split_pud event for clarify

[Yisheng Xie]

We added supporting for PUD-sized transparent hugepages, however count
the event "thp split pud" into thp_split_pmd event.

To clarify the event count of thp split pud from pmd, this patch add a
new event named thp_split_pud.

Signed-off-by: Yisheng Xie <xieyisheng1@xxxxxxxxxx>
---
 include/linux/vm_event_item.h | 3 +++
 mm/huge_memory.c              | 2 +-
 mm/vmstat.c                   | 3 +++
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h
index 6aa1b6c..a80b7b5 100644
--- a/include/linux/vm_event_item.h
+++ b/include/linux/vm_event_item.h
@@ -79,6 +79,9 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
 		THP_SPLIT_PAGE_FAILED,
 		THP_DEFERRED_SPLIT_PAGE,
 		THP_SPLIT_PMD,
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+		THP_SPLIT_PUD,
+#endif
 		THP_ZERO_PAGE_ALLOC,
 		THP_ZERO_PAGE_ALLOC_FAILED,
 #endif
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 71e3ded..0bfcd72 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1826,7 +1826,7 @@ static void __split_huge_pud_locked(struct vm_area_struct *vma, pud_t *pud,
 	VM_BUG_ON_VMA(vma->vm_end < haddr + HPAGE_PUD_SIZE, vma);
 	VM_BUG_ON(!pud_trans_huge(*pud) && !pud_devmap(*pud));
 
-	count_vm_event(THP_SPLIT_PMD);
+	count_vm_event(THP_SPLIT_PUD);
 
 	pudp_huge_clear_flush_notify(vma, haddr, pud);
 }
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 69f9aff..b1947f0 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1065,6 +1065,9 @@ int fragmentation_index(struct zone *zone, unsigned int order)
 	"thp_split_page_failed",
 	"thp_deferred_split_page",
 	"thp_split_pmd",
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+	"thp_split_pud",
+#endif
 	"thp_zero_page_alloc",
 	"thp_zero_page_alloc_failed",
 #endif
-- 
1.7.12.4