Re: [PATCH v2 2/9] perf tools: splice events onto evlist even on error

From
Jiri Olsa <hidden>
Date
2019-10-23 08:40:54
Also in
bpf, lkml
Reply to
Ian Rogers, 2019-10-23
On Tue, Oct 22, 2019 at 05:53:30PM -0700, Ian Rogers wrote:
quoted hunk ↗ jump to hunk
If event parsing fails the event list is leaked, instead splice the list
onto the out result and let the caller cleanup.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/parse-events.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 4d42344698b8..a8f8801bd127 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -1962,15 +1962,20 @@ int parse_events(struct evlist *evlist, const char *str,
 
 	ret = parse_events__scanner(str, &parse_state, PE_START_EVENTS);
 	perf_pmu__parse_cleanup();
+
I dont understand.. is there something on the list in case we fail?
quoted hunk ↗ jump to hunk
+	if (list_empty(&parse_state.list)) {
+		WARN_ONCE(true, "WARNING: event parser found nothing\n");
+		return -1;
+	}
this will display extra warning message for fail case:

[jolsa@krava perf]$ ./perf record -e krava ls
WARNING: event parser found nothing
event syntax error: 'krava'
                     \___ parser error

we don't want that

jirka
+
+	/*
+	 * Add list to the evlist even with errors to allow callers to clean up.
+	 */
+	perf_evlist__splice_list_tail(evlist, &parse_state.list);
+
 	if (!ret) {
 		struct evsel *last;
 
-		if (list_empty(&parse_state.list)) {
-			WARN_ONCE(true, "WARNING: event parser found nothing\n");
-			return -1;
-		}
-
-		perf_evlist__splice_list_tail(evlist, &parse_state.list);
 		evlist->nr_groups += parse_state.nr_groups;
 		last = evlist__last(evlist);
 		last->cmdline_group_boundary = true;
-- 
2.23.0.866.gb869b98d4c-goog
  
Thread (101 messages) 101 messages, 4 authors, last reply 2019-11-12
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