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Date:   Wed, 26 Apr 2023 00:00:24 -0700
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Subject: [PATCH v1 14/40] perf print-events: Avoid unnecessary strlist
From:   Ian Rogers <irogers@google.com>
To:     Arnaldo Carvalho de Melo <acme@kernel.org>,
        Kan Liang <kan.liang@linux.intel.com>,
        Ahmad Yasin <ahmad.yasin@intel.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Stephane Eranian <eranian@google.com>,
        Andi Kleen <ak@linux.intel.com>,
        Perry Taylor <perry.taylor@intel.com>,
        Samantha Alt <samantha.alt@intel.com>,
        Caleb Biggers <caleb.biggers@intel.com>,
        Weilin Wang <weilin.wang@intel.com>,
        Edward Baker <edward.baker@intel.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Florian Fischer <florian.fischer@muhq.space>,
        Rob Herring <robh@kernel.org>,
        Zhengjun Xing <zhengjun.xing@linux.intel.com>,
        John Garry <john.g.garry@oracle.com>,
        Kajol Jain <kjain@linux.ibm.com>,
        Sumanth Korikkar <sumanthk@linux.ibm.com>,
        Thomas Richter <tmricht@linux.ibm.com>,
        Tiezhu Yang <yangtiezhu@loongson.cn>,
        Ravi Bangoria <ravi.bangoria@amd.com>,
        Leo Yan <leo.yan@linaro.org>,
        Yang Jihong <yangjihong1@huawei.com>,
        James Clark <james.clark@arm.com>,
        Suzuki Poulouse <suzuki.poulose@arm.com>,
        Kang Minchul <tegongkang@gmail.com>,
        Athira Rajeev <atrajeev@linux.vnet.ibm.com>,
        linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     Ian Rogers <irogers@google.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

The strlist in print_hwcache_events holds the event names as they are
generated, and then it is iterated and printed. This is unnecessary
and each event can just be printed as it is processed.
Rename the variable i to res, to be more intention revealing and
consistent with other code.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/print-events.c | 60 ++++++++++++++++++----------------
 1 file changed, 31 insertions(+), 29 deletions(-)

diff --git a/tools/perf/util/print-events.c b/tools/perf/util/print-events.c
index 386b1ab0b60e..93bbb868d400 100644
--- a/tools/perf/util/print-events.c
+++ b/tools/perf/util/print-events.c
@@ -226,58 +226,60 @@ void print_sdt_events(const struct print_callbacks *print_cb, void *print_state)
 
 int print_hwcache_events(const struct print_callbacks *print_cb, void *print_state)
 {
-	struct strlist *evt_name_list = strlist__new(NULL, NULL);
-	struct str_node *nd;
+	const char *event_type_descriptor = event_type_descriptors[PERF_TYPE_HW_CACHE];
 
-	if (!evt_name_list) {
-		pr_debug("Failed to allocate new strlist for hwcache events\n");
-		return -ENOMEM;
-	}
 	for (int type = 0; type < PERF_COUNT_HW_CACHE_MAX; type++) {
 		for (int op = 0; op < PERF_COUNT_HW_CACHE_OP_MAX; op++) {
 			/* skip invalid cache type */
 			if (!evsel__is_cache_op_valid(type, op))
 				continue;
 
-			for (int i = 0; i < PERF_COUNT_HW_CACHE_RESULT_MAX; i++) {
+			for (int res = 0; res < PERF_COUNT_HW_CACHE_RESULT_MAX; res++) {
 				struct perf_pmu *pmu = NULL;
 				char name[64];
 
-				__evsel__hw_cache_type_op_res_name(type, op, i, name, sizeof(name));
+				__evsel__hw_cache_type_op_res_name(type, op, res,
+								   name, sizeof(name));
 				if (!perf_pmu__has_hybrid()) {
 					if (is_event_supported(PERF_TYPE_HW_CACHE,
-							       type | (op << 8) | (i << 16)))
-						strlist__add(evt_name_list, name);
+								type | (op << 8) | (res << 16))) {
+						print_cb->print_event(print_state,
+								"cache",
+								/*pmu_name=*/NULL,
+								name,
+								/*event_alias=*/NULL,
+								/*scale_unit=*/NULL,
+								/*deprecated=*/false,
+								event_type_descriptor,
+								/*desc=*/NULL,
+								/*long_desc=*/NULL,
+								/*encoding_desc=*/NULL);
+					}
 					continue;
 				}
 				perf_pmu__for_each_hybrid_pmu(pmu) {
 					if (is_event_supported(PERF_TYPE_HW_CACHE,
-					    type | (op << 8) | (i << 16) |
+					    type | (op << 8) | (res << 16) |
 					    ((__u64)pmu->type << PERF_PMU_TYPE_SHIFT))) {
 						char new_name[128];
-							snprintf(new_name, sizeof(new_name),
-								 "%s/%s/", pmu->name, name);
-							strlist__add(evt_name_list, new_name);
+						snprintf(new_name, sizeof(new_name),
+							"%s/%s/", pmu->name, name);
+						print_cb->print_event(print_state,
+								"cache",
+								pmu->name,
+								name,
+								new_name,
+								/*scale_unit=*/NULL,
+								/*deprecated=*/false,
+								event_type_descriptor,
+								/*desc=*/NULL,
+								/*long_desc=*/NULL,
+								/*encoding_desc=*/NULL);
 					}
 				}
 			}
 		}
 	}
-
-	strlist__for_each_entry(nd, evt_name_list) {
-		print_cb->print_event(print_state,
-				"cache",
-				/*pmu_name=*/NULL,
-				nd->s,
-				/*event_alias=*/NULL,
-				/*scale_unit=*/NULL,
-				/*deprecated=*/false,
-				event_type_descriptors[PERF_TYPE_HW_CACHE],
-				/*desc=*/NULL,
-				/*long_desc=*/NULL,
-				/*encoding_desc=*/NULL);
-	}
-	strlist__delete(evt_name_list);
 	return 0;
 }
 
-- 
2.40.1.495.gc816e09b53d-goog