From: Vernon Yang <yanglincheng@kylinos.cn>

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>
Reviewed-by: Barry Song <baohua@kernel.org>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Dev Jain <dev.jain@arm.com>
---
 include/trace/events/huge_memory.h | 25 +++++++++++++++++++++++++
 mm/khugepaged.c                    |  2 ++
 2 files changed, 27 insertions(+)

diff --git a/include/trace/events/huge_memory.h b/include/trace/events/huge_memory.h
index 4e41bff31888..384e29f6bef0 100644
--- a/include/trace/events/huge_memory.h
+++ b/include/trace/events/huge_memory.h
@@ -237,5 +237,30 @@ TRACE_EVENT(mm_khugepaged_collapse_file,
 		__print_symbolic(__entry->result, SCAN_STATUS))
 );
 
+TRACE_EVENT(mm_khugepaged_scan,
+
+	TP_PROTO(struct mm_struct *mm, unsigned int progress,
+		 bool full_scan_finished),
+
+	TP_ARGS(mm, progress, full_scan_finished),
+
+	TP_STRUCT__entry(
+		__field(struct mm_struct *, mm)
+		__field(unsigned 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=%u, 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 c0f893bebcff..e2f6b68a0011 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -2527,6 +2527,8 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, enum scan_result
 		collect_mm_slot(slot);
 	}
 
+	trace_mm_khugepaged_scan(mm, progress, khugepaged_scan.mm_slot == NULL);
+
 	return progress;
 }
 
-- 
2.51.0

On Sat, Feb 21, 2026 at 05:39:15PM +0800, Vernon Yang wrote:
> From: Vernon Yang <yanglincheng@kylinos.cn>
>
> 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>
> Reviewed-by: Barry Song <baohua@kernel.org>
> Reviewed-by: Lance Yang <lance.yang@linux.dev>
> Reviewed-by: Dev Jain <dev.jain@arm.com>

LGTM, so:

Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>

> ---
>  include/trace/events/huge_memory.h | 25 +++++++++++++++++++++++++
>  mm/khugepaged.c                    |  2 ++
>  2 files changed, 27 insertions(+)
>
> diff --git a/include/trace/events/huge_memory.h b/include/trace/events/huge_memory.h
> index 4e41bff31888..384e29f6bef0 100644
> --- a/include/trace/events/huge_memory.h
> +++ b/include/trace/events/huge_memory.h
> @@ -237,5 +237,30 @@ TRACE_EVENT(mm_khugepaged_collapse_file,
>  		__print_symbolic(__entry->result, SCAN_STATUS))
>  );
>
> +TRACE_EVENT(mm_khugepaged_scan,
> +
> +	TP_PROTO(struct mm_struct *mm, unsigned int progress,
> +		 bool full_scan_finished),
> +
> +	TP_ARGS(mm, progress, full_scan_finished),
> +
> +	TP_STRUCT__entry(
> +		__field(struct mm_struct *, mm)
> +		__field(unsigned 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=%u, 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 c0f893bebcff..e2f6b68a0011 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -2527,6 +2527,8 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, enum scan_result
>  		collect_mm_slot(slot);
>  	}
>
> +	trace_mm_khugepaged_scan(mm, progress, khugepaged_scan.mm_slot == NULL);
> +
>  	return progress;
>  }
>
> --
> 2.51.0
>