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

["David Hildenbrand (Red Hat)" <david@kernel.org>]

On 12/15/25 10:04, Vernon Yang wrote:
> 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>
> ---
>   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 dd94d14a2427..b2824c2f8238 100644
> --- a/include/trace/events/huge_memory.h
> +++ b/include/trace/events/huge_memory.h
> @@ -237,5 +237,29 @@ 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),
> +
> +	TP_ARGS(mm, progress, full),
> +
> +	TP_STRUCT__entry(
> +		__field(struct mm_struct *, mm)
> +		__field(int, progress)
> +		__field(bool, full)
> +	),
> +
> +	TP_fast_assign(
> +		__entry->mm = mm;
> +		__entry->progress = progress;
> +		__entry->full = full;
> +	),
> +
> +	TP_printk("mm=%p, progress=%d, full=%d",
> +		__entry->mm,
> +		__entry->progress,
> +		__entry->full)
> +);
> +
>   #endif /* __HUGE_MEMORY_H */
>   #include <trace/define_trace.h>
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index abe54f0043c7..0598a19a98cc 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -2516,6 +2516,8 @@ 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;
>   }
>   

Nothing jumped at me, except that "full" could be called 
"full_scan_finished" or smth like that.

Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>

-- 
Cheers

David