From 90b2c210a54e657ea8fcba3d724dba180c716edc Mon Sep 17 00:00:00 2001
From: Ian Rogers <irogers@google.com>
Date: Mon, 15 Apr 2024 23:15:19 -0700
Subject: [PATCH] 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: Ian Rogers <irogers@google.com>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Tested-by: Atish 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: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/parse-events.c | 25 +++++++++++++------------
1 file changed, 13 insertions(+), 12 deletions(-)
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 2d5a275dd257e..3b1f767039fa6 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -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);
--
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