From: Adrian Hunter adrian.hunter@intel.com
[ Upstream commit faf59ec8c3c3708c64ff76b50e6f757c6b4a1054 ]
Some calls to synthesis functions set err < 0 but only warn about the failure and continue. However they do not set err back to zero, relying on subsequent code to do that.
That changed with the introduction of option --synth. When --synth=no subsequent functions that set err back to zero are not called.
Fix by setting err = 0 in those cases.
Example:
Before:
$ perf record --no-bpf-event --synth=all -o /tmp/huh uname Couldn't synthesize bpf events. Linux [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.014 MB /tmp/huh (7 samples) ] $ perf record --no-bpf-event --synth=no -o /tmp/huh uname Couldn't synthesize bpf events.
After:
$ perf record --no-bpf-event --synth=no -o /tmp/huh uname Couldn't synthesize bpf events. Linux [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.014 MB /tmp/huh (7 samples) ]
Fixes: 41b740b6e8a994e5 ("perf record: Add --synth option") Signed-off-by: Adrian Hunter adrian.hunter@intel.com Acked-by: Namhyung Kim namhyung@kernel.org Cc: Ian Rogers irogers@google.com Cc: Jiri Olsa jolsa@kernel.org Cc: Namhyung Kim namhyung@kernel.org Link: https://lore.kernel.org/r/20220907162458.72817-1-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/builtin-record.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 9a71f0330137e..68c878b4e5e4c 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -1892,14 +1892,18 @@ static int record__synthesize(struct record *rec, bool tail)
err = perf_event__synthesize_bpf_events(session, process_synthesized_event, machine, opts); - if (err < 0) + if (err < 0) { pr_warning("Couldn't synthesize bpf events.\n"); + err = 0; + }
if (rec->opts.synth & PERF_SYNTH_CGROUP) { err = perf_event__synthesize_cgroups(tool, process_synthesized_event, machine); - if (err < 0) + if (err < 0) { pr_warning("Couldn't synthesize cgroup events.\n"); + err = 0; + } }
if (rec->opts.nr_threads_synthesize > 1) {