[PATCH v2] perf arm-spe: Report error if set frequency
Leo Yan
leo.yan at arm.com
Thu Feb 27 00:55:44 PST 2025
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 1000 -e arm_spe_0// -- sleep 1
Arm SPE: Frequency is not supported. Set period with -c option or PMU parameter (-e arm_spe_0/period=NUM/).
Signed-off-by: Leo Yan <leo.yan at arm.com>
---
Changes from v1:
- Sugguested users for '-c' option or PMU parameter 'period' in the log
(Namhyung)
tools/perf/arch/arm64/util/arm-spe.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/tools/perf/arch/arm64/util/arm-spe.c b/tools/perf/arch/arm64/util/arm-spe.c
index 4301181b8e45..4f2833b62ff5 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 +402,14 @@ 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. "
+ "Set period with -c option or PMU parameter (-e %s/period=NUM/).\n",
+ evsel->pmu->name);
+ return -EINVAL;
+ }
}
}
--
2.25.1
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