Re: [PATCH v3 04/20] perf arm-spe: Refactor arm_spe_get_events()

[André Przywara]

On 22/10/2020 15:58, Leo Yan wrote:
> In function arm_spe_get_events(), the event packet's 'index' is assigned
> as payload length, but the flow is not directive: it firstly gets the
> packet length from the return value of arm_spe_get_payload(), the value
> includes header length (1) and payload length:
> 
>   int ret = arm_spe_get_payload(buf, len, packet);
> 
> and then reduces header length from packet length, so finally get the
> payload length:
> 
>   packet->index = ret - 1;
> 
> To simplify the code, this patch directly assigns payload length to
> event packet's index; and at the end it calls arm_spe_get_payload() to
> return the payload value.
> 
> Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>

Reviewed-by: Andre Przywara <andre.przywara@xxxxxxx>

Cheers,
Andre

> ---
>  tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c b/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
> index 4294c133a465..f3bb8bf102aa 100644
> --- a/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
> +++ b/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
> @@ -136,8 +136,6 @@ static int arm_spe_get_timestamp(const unsigned char *buf, size_t len,
>  static int arm_spe_get_events(const unsigned char *buf, size_t len,
>  			      struct arm_spe_pkt *packet)
>  {
> -	int ret = arm_spe_get_payload(buf, len, packet);
> -
>  	packet->type = ARM_SPE_EVENTS;
>  
>  	/* we use index to identify Events with a less number of
> @@ -145,9 +143,9 @@ static int arm_spe_get_events(const unsigned char *buf, size_t len,
>  	 * LLC-REFILL, and REMOTE-ACCESS events are identified if
>  	 * index > 1.
>  	 */
> -	packet->index = ret - 1;
> +	packet->index = arm_spe_payload_len(buf[0]);
>  
> -	return ret;
> +	return arm_spe_get_payload(buf, len, packet);
>  }
>  
>  static int arm_spe_get_data_source(const unsigned char *buf, size_t len,
>