From 0f9f9c73da37c945bb14363378908342e7e5db59 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Wed, 7 Sep 2022 19:24:58 +0300 Subject: [PATCH] perf record: Fix synthesis failure warnings [ 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 Acked-by: Namhyung Kim Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lore.kernel.org/r/20220907162458.72817-1-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- 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) {