[PATCH v2 1/4] mm: khugepaged: add trace_mm_khugepaged_scan event

[Vernon Yang <vernon2gm@gmail.com>]

Add mm_khugepaged_scan event to track the total time for full scan
and the total number of pages scanned of khugepaged.

Signed-off-by: Vernon Yang <yanglincheng@kylinos.cn>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
---
 include/trace/events/huge_memory.h | 24 ++++++++++++++++++++++++
 mm/khugepaged.c                    |  2 ++
 2 files changed, 26 insertions(+)

diff --git a/include/trace/events/huge_memory.h b/include/trace/events/huge_memory.h
index 4cde53b45a85..01225dd27ad5 100644
--- a/include/trace/events/huge_memory.h
+++ b/include/trace/events/huge_memory.h
@@ -236,5 +236,29 @@ TRACE_EVENT(mm_khugepaged_collapse_file,
 		__print_symbolic(__entry->result, SCAN_STATUS))
 );
 
+TRACE_EVENT(mm_khugepaged_scan,
+
+	TP_PROTO(struct mm_struct *mm, int progress, bool full_scan_finished),
+
+	TP_ARGS(mm, progress, full_scan_finished),
+
+	TP_STRUCT__entry(
+		__field(struct mm_struct *, mm)
+		__field(int, progress)
+		__field(bool, full_scan_finished)
+	),
+
+	TP_fast_assign(
+		__entry->mm = mm;
+		__entry->progress = progress;
+		__entry->full_scan_finished = full_scan_finished;
+	),
+
+	TP_printk("mm=%p, progress=%d, full_scan_finished=%d",
+		__entry->mm,
+		__entry->progress,
+		__entry->full_scan_finished)
+);
+
 #endif /* __HUGE_MEMORY_H */
 #include <trace/define_trace.h>
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 97d1b2824386..9f99f61689f8 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -2533,6 +2533,8 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, int *result,
 		collect_mm_slot(slot);
 	}
 
+	trace_mm_khugepaged_scan(mm, progress, khugepaged_scan.mm_slot == NULL);
+
 	return progress;
 }
 
-- 
2.51.0