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authorNamhyung Kim <namhyung@kernel.org>2025-11-20 15:48:04 -0800
committerNamhyung Kim <namhyung@kernel.org>2025-12-02 21:59:14 -0800
commit405f5756bbd231e6b70949909a526bdaf538e2fc (patch)
tree6ea340dfee572a8f6b6265494b71ec30f6e0f6fc
parent9b4525fd089decf3557eff4a3ef348cdc2b68353 (diff)
downloadtip-405f5756bbd231e6b70949909a526bdaf538e2fc.tar.gz
perf tools: Flush remaining samples w/o deferred callchains
It's possible that some kernel samples don't have matching deferred callchain records when the profiling session was ended before the threads came back to userspace. Let's flush the samples before finish the session. Reviewed-by: Ian Rogers <irogers@google.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
-rw-r--r--tools/perf/util/session.c50
1 files changed, 50 insertions, 0 deletions
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index dc570ad47ccc2c..4236503c8f6c13 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1295,6 +1295,10 @@ struct deferred_event {
union perf_event *event;
};
+/*
+ * This is called when a deferred callchain record comes up. Find all matching
+ * samples, merge the callchains and process them.
+ */
static int evlist__deliver_deferred_callchain(struct evlist *evlist,
const struct perf_tool *tool,
union perf_event *event,
@@ -1345,6 +1349,42 @@ static int evlist__deliver_deferred_callchain(struct evlist *evlist,
return ret;
}
+/*
+ * This is called at the end of the data processing for the session. Flush the
+ * remaining samples as there's no hope for matching deferred callchains.
+ */
+static int session__flush_deferred_samples(struct perf_session *session,
+ const struct perf_tool *tool)
+{
+ struct evlist *evlist = session->evlist;
+ struct machine *machine = &session->machines.host;
+ struct deferred_event *de, *tmp;
+ struct evsel *evsel;
+ int ret = 0;
+
+ list_for_each_entry_safe(de, tmp, &evlist->deferred_samples, list) {
+ struct perf_sample sample;
+
+ ret = evlist__parse_sample(evlist, de->event, &sample);
+ if (ret < 0) {
+ pr_err("failed to parse original sample\n");
+ break;
+ }
+
+ evsel = evlist__id2evsel(evlist, sample.id);
+ ret = evlist__deliver_sample(evlist, tool, de->event,
+ &sample, evsel, machine);
+
+ list_del(&de->list);
+ free(de->event);
+ free(de);
+
+ if (ret)
+ break;
+ }
+ return ret;
+}
+
static int machines__deliver_event(struct machines *machines,
struct evlist *evlist,
union perf_event *event,
@@ -2040,6 +2080,9 @@ done:
err = ordered_events__flush(oe, OE_FLUSH__FINAL);
if (err)
goto out_err;
+ err = session__flush_deferred_samples(session, tool);
+ if (err)
+ goto out_err;
err = auxtrace__flush_events(session, tool);
if (err)
goto out_err;
@@ -2386,6 +2429,9 @@ static int __perf_session__process_events(struct perf_session *session)
err = auxtrace__flush_events(session, tool);
if (err)
goto out_err;
+ err = session__flush_deferred_samples(session, tool);
+ if (err)
+ goto out_err;
err = perf_session__flush_thread_stacks(session);
out_err:
ui_progress__finish();
@@ -2506,6 +2552,10 @@ static int __perf_session__process_dir_events(struct perf_session *session)
if (ret)
goto out_err;
+ ret = session__flush_deferred_samples(session, tool);
+ if (ret)
+ goto out_err;
+
ret = perf_session__flush_thread_stacks(session);
out_err:
ui_progress__finish();