Re: [RESEND PATCH v12 1/3] perf tool: arm: Refactor event list iteration in auxtrace_record__init()

From: John Garry
Date: Wed Sep 14 2022 - 09:48:15 EST


On 14/09/2022 08:59, Yicong Yang wrote:
From: Qi Liu <liuqi115@xxxxxxxxxx>

Add find_pmu_for_event() and use to simplify logic in
auxtrace_record_init(). find_pmu_for_event() will be
reused in subsequent patches.

Reviewed-by: Leo Yan <leo.yan@xxxxxxxxxx>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Qi Liu <liuqi115@xxxxxxxxxx>
Signed-off-by: Yicong Yang <yangyicong@xxxxxxxxxxxxx>
---
tools/perf/arch/arm/util/auxtrace.c | 53 ++++++++++++++++++-----------
1 file changed, 34 insertions(+), 19 deletions(-)

diff --git a/tools/perf/arch/arm/util/auxtrace.c b/tools/perf/arch/arm/util/auxtrace.c
index 5fc6a2a3dbc5..384c7cfda0fd 100644
--- a/tools/perf/arch/arm/util/auxtrace.c
+++ b/tools/perf/arch/arm/util/auxtrace.c
@@ -50,16 +50,32 @@ static struct perf_pmu **find_all_arm_spe_pmus(int *nr_spes, int *err)
return arm_spe_pmus;
}
+static struct perf_pmu *find_pmu_for_event(struct perf_pmu **pmus,
+ int pmu_nr, struct evsel *evsel)
+{
+ int i;
+
+ if (!pmus)
+ return NULL;
+
+ for (i = 0; i < pmu_nr; i++) {
+ if (evsel->core.attr.type == pmus[i]->type)
+ return pmus[i];
+ }
+
+ return NULL;
+}
+
struct auxtrace_record
*auxtrace_record__init(struct evlist *evlist, int *err)
{
- struct perf_pmu *cs_etm_pmu;
+ struct perf_pmu *cs_etm_pmu = NULL;
+ struct perf_pmu **arm_spe_pmus = NULL;
struct evsel *evsel;
- bool found_etm = false;
+ struct perf_pmu *found_etm = NULL;
struct perf_pmu *found_spe = NULL;
- struct perf_pmu **arm_spe_pmus = NULL;
+ int auxtrace_event_cnt = 0;
int nr_spes = 0;
- int i = 0;
if (!evlist)
return NULL;
@@ -68,24 +84,23 @@ struct auxtrace_record
arm_spe_pmus = find_all_arm_spe_pmus(&nr_spes, err);
evlist__for_each_entry(evlist, evsel) {
- if (cs_etm_pmu &&
- evsel->core.attr.type == cs_etm_pmu->type)
- found_etm = true;
-
- if (!nr_spes || found_spe)
- continue;
-
- for (i = 0; i < nr_spes; i++) {
- if (evsel->core.attr.type == arm_spe_pmus[i]->type) {
- found_spe = arm_spe_pmus[i];
- break;
- }
- }
+ if (cs_etm_pmu && !found_etm) + found_etm = find_pmu_for_event(&cs_etm_pmu, 1, evsel);
+
+ if (arm_spe_pmus && !found_spe)
+ found_spe = find_pmu_for_event(arm_spe_pmus, nr_spes, evsel);

should you break if found_etm and found_spe are set? Or, indeed, error and return directly as we do below? Indeed, I am not sure why you even require auxtrace_event_cnt

}
+
free(arm_spe_pmus);
- if (found_etm && found_spe) {
- pr_err("Concurrent ARM Coresight ETM and SPE operation not currently supported\n");
+ if (found_etm)
+ auxtrace_event_cnt++;
+
+ if (found_spe)
+ auxtrace_event_cnt++;
+
+ if (auxtrace_event_cnt > 1) {
+ pr_err("Concurrent AUX trace operation not currently supported\n");
*err = -EOPNOTSUPP;
return NULL;
}