Re: [PATCH 10/12] perf arm_spe: Refactor arm_spe__get_metadata_by_cpu()

[James Clark <james.clark@linaro.org>]

On 13/06/2025 4:53 pm, Leo Yan wrote:
> Handle "CPU=-1" (per-thread mode) in the arm_spe__get_metadata_by_cpu()
> function. As a result, the function is more general and will be invoked
> by a sequential change.
> 
> Signed-off-by: Leo Yan <leo.yan@arm.com>
> ---
>   tools/perf/util/arm-spe.c | 30 ++++++++++++++----------------
>   1 file changed, 14 insertions(+), 16 deletions(-)
> 
> diff --git a/tools/perf/util/arm-spe.c b/tools/perf/util/arm-spe.c
> index 2ab38d21d52f73617451a6a79f9d5ae931a34f49..8e93b0d151a98714d0c5e5f6ceec386a2aa63ad0 100644
> --- a/tools/perf/util/arm-spe.c
> +++ b/tools/perf/util/arm-spe.c
> @@ -324,6 +324,19 @@ static u64 *arm_spe__get_metadata_by_cpu(struct arm_spe *spe, u64 cpu)
>   	if (!spe->metadata)
>   		return NULL;
>   
> +	/* CPU ID is -1 for per-thread mode */
> +	if (cpu < 0) {
> +		/*
> +		 * On the heterogeneous system, due to CPU ID is -1,
> +		 * cannot confirm the meta data.
> +		 */
> +		if (!spe->is_homogeneous)
> +			return NULL;
> +
> +		/* In homogeneous system, simply use CPU0's metadata */
> +		return spe->metadata[0];
> +	}
> +
>   	for (i = 0; i < spe->metadata_nr_cpu; i++)
>   		if (spe->metadata[i][ARM_SPE_CPU] == cpu)
>   			return spe->metadata[i];
> @@ -924,22 +937,7 @@ static bool arm_spe__synth_ds(struct arm_spe_queue *speq,
>   		cpuid = perf_env__cpuid(spe->session->evlist->env);
>   		midr = strtol(cpuid, NULL, 16);
>   	} else {
> -		/* CPU ID is -1 for per-thread mode */
> -		if (speq->cpu < 0) {
> -			/*
> -			 * On the heterogeneous system, due to CPU ID is -1,
> -			 * cannot confirm the data source packet is supported.
> -			 */
> -			if (!spe->is_homogeneous)
> -				return false;
> -
> -			/* In homogeneous system, simply use CPU0's metadata */
> -			if (spe->metadata)
> -				metadata = spe->metadata[0];
> -		} else {
> -			metadata = arm_spe__get_metadata_by_cpu(spe, speq->cpu);
> -		}
> -
> +		metadata = arm_spe__get_metadata_by_cpu(spe, speq->cpu);
>   		if (!metadata)
>   			return false;
>   
> 

Reviewed-by: James Clark <james.clark@linaro.org>