Commit 90b2c210 authored by Ian Rogers's avatar Ian Rogers Committed by Arnaldo Carvalho de Melo
Browse files

perf parse-events: Avoid copying an empty list 



In parse_events_add_pmu, delay copying the list of terms until it is
known the list contains terms.

Signed-off-by: default avatarIan Rogers <irogers@google.com>
Reviewed-by: default avatarKan Liang <kan.liang@linux.intel.com>
Tested-by: default avatarAtish Patra <atishp@rivosinc.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Beeman Strong <beeman@rivosinc.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240416061533.921723-4-irogers@google.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 63dfcde9

tools/perf/util/parse-events.c

+13 −12
Original line number Diff line number Diff line
@@ -1398,29 +1398,21 @@ static int parse_events_add_pmu(struct parse_events_state *parse_state, 
	struct parse_events_terms parsed_terms;

	bool alias_rewrote_terms = false;



	parse_events_terms__init(&parsed_terms);

	if (const_parsed_terms) {

		int ret = parse_events_terms__copy(const_parsed_terms, &parsed_terms);



		if (ret)

			return ret;

	}



	if (verbose > 1) {

		struct strbuf sb;



		strbuf_init(&sb, /*hint=*/ 0);

		if (pmu->selectable && list_empty(&parsed_terms.terms)) {

		if (pmu->selectable && const_parsed_terms &&

		    list_empty(&const_parsed_terms->terms)) {

			strbuf_addf(&sb, "%s//", pmu->name);

		} else {

			strbuf_addf(&sb, "%s/", pmu->name);

			parse_events_terms__to_strbuf(&parsed_terms, &sb);

			parse_events_terms__to_strbuf(const_parsed_terms, &sb);

			strbuf_addch(&sb, '/');

		}

		fprintf(stderr, "Attempt to add: %s\n", sb.buf);

		strbuf_release(&sb);

	}

	fix_raw(&parsed_terms, pmu);



	memset(&attr, 0, sizeof(attr));

	if (pmu->perf_event_attr_init_default)
@@ -1428,7 +1420,7 @@ static int parse_events_add_pmu(struct parse_events_state *parse_state, 


	attr.type = pmu->type;



	if (list_empty(&parsed_terms.terms)) {

	if (!const_parsed_terms || list_empty(&const_parsed_terms->terms)) {

		evsel = __add_event(list, &parse_state->idx, &attr,

				    /*init_attr=*/true, /*name=*/NULL,

				    /*metric_id=*/NULL, pmu,
@@ -1437,6 +1429,15 @@ static int parse_events_add_pmu(struct parse_events_state *parse_state, 
		return evsel ? 0 : -ENOMEM;

	}



	parse_events_terms__init(&parsed_terms);

	if (const_parsed_terms) {

		int ret = parse_events_terms__copy(const_parsed_terms, &parsed_terms);



		if (ret)

			return ret;

	}

	fix_raw(&parsed_terms, pmu);



	/* Configure attr/terms with a known PMU, this will set hardcoded terms. */

	if (config_attr(&attr, &parsed_terms, parse_state->error, config_term_pmu)) {

		parse_events_terms__exit(&parsed_terms);