[PATCH] perf arm-spe: Report error if set frequency
Leo Yan
leo.yan at arm.com
Mon Feb 17 00:20:08 PST 2025
On Wed, Feb 05, 2025 at 06:30:09PM +0000, Leo Yan wrote:
> When users set the parameter '-F' to specify frequency for Arm SPE, the
> tool reports error:
>
> perf record -F 1000 -e arm_spe_0// -- sleep 1
> Error:
> Invalid event (arm_spe_0//) in per-thread mode, enable system wide with '-a'.
>
> The output logs are confused and it does not give the correct reminding.
> Arm SPE does not support frequency setting given it adopts a statistical
> based approach.
>
> Alternatively, Arm SPE supports setting period. This commit adds a
> for frequency setting. It reports error and reminds users to set period
> instead.
>
> After:
>
> perf record -F 100 -e arm_spe_0// -- sleep 1
> Arm SPE: Frequency is not supported. Check manual 'man perf-record' on how to set period.
>
> Signed-off-by: Leo Yan <leo.yan at arm.com>
Gentle ping.
> ---
> tools/perf/arch/arm64/util/arm-spe.c | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/tools/perf/arch/arm64/util/arm-spe.c b/tools/perf/arch/arm64/util/arm-spe.c
> index 4301181b8e45..baef0812dc19 100644
> --- a/tools/perf/arch/arm64/util/arm-spe.c
> +++ b/tools/perf/arch/arm64/util/arm-spe.c
> @@ -40,6 +40,19 @@ struct arm_spe_recording {
> bool *wrapped;
> };
>
> +/* Iterate config list to detect if the "freq" parameter is set */
> +static bool arm_spe_is_set_freq(struct evsel *evsel)
> +{
> + struct evsel_config_term *term;
> +
> + list_for_each_entry(term, &evsel->config_terms, list) {
> + if (term->type == EVSEL__CONFIG_TERM_FREQ)
> + return true;
> + }
> +
> + return false;
> +}
> +
> /*
> * arm_spe_find_cpus() returns a new cpu map, and the caller should invoke
> * perf_cpu_map__put() to release the map after use.
> @@ -389,6 +402,13 @@ static int arm_spe_recording_options(struct auxtrace_record *itr,
> return -EINVAL;
> }
> opts->full_auxtrace = true;
> +
> + if (opts->user_freq != UINT_MAX ||
> + arm_spe_is_set_freq(evsel)) {
> + pr_err("Arm SPE: Frequency is not supported. "
> + "Check manual 'man perf-record' on how to set period.\n");
> + return -EINVAL;
> + }
> }
> }
>
> --
> 2.34.1
>
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