Re: [PATCH 13/16] perf: Add a speculative page fault sw events

[Michael Ellerman]

Laurent Dufour <ldufour@xxxxxxxxxxxxxxxxxx> writes:

> Add new software events to count succeeded and failed speculative page
> faults.
>
> Signed-off-by: Laurent Dufour <ldufour@xxxxxxxxxxxxxxxxxx>
> ---
>  include/uapi/linux/perf_event.h | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
> index b1c0b187acfe..fbfb03dff334 100644
> --- a/include/uapi/linux/perf_event.h
> +++ b/include/uapi/linux/perf_event.h
> @@ -111,6 +111,8 @@ enum perf_sw_ids {
>  	PERF_COUNT_SW_EMULATION_FAULTS		= 8,
>  	PERF_COUNT_SW_DUMMY			= 9,
>  	PERF_COUNT_SW_BPF_OUTPUT		= 10,
> +	PERF_COUNT_SW_SPF_DONE			= 11,
> +	PERF_COUNT_SW_SPF_FAILED		= 12,

Can't you calculate:

  PERF_COUNT_SW_SPF_FAILED = PERF_COUNT_SW_PAGE_FAULTS - PERF_COUNT_SW_SPF_DONE

ie. do you need a separate event for it?

cheers