Hello,
On Sun, Apr 26, 2026 at 12:13:01PM +0530, Athira Rajeev wrote:
> perf trace record fails some cases in powerpc
>
> # ./perf test "perf trace record and replay"
> 128: perf trace record and replay :
> FAILED!
>
> # ./perf trace record sleep 1
> # echo $?
> 32
>
> This is happening because of non-zero err value from
> auxtrace_record__init() function.
>
> static int record__auxtrace_init(struct record *rec)
> {
> int err;
>
> if ((rec->opts.auxtrace_snapshot_opts ||
> rec->opts.auxtrace_sample_opts)
> && record__threads_enabled(rec)) {
> pr_err("AUX area tracing options are not available in
> parallel streaming mode.\n");
> return -EINVAL;
> }
>
> if (!rec->itr) {
> rec->itr = auxtrace_record__init(rec->evlist, &err);
> if (err)
> return err;
> }
>
> Here "int err" is not initialised. The code expects "err" to be set
> from auxtrace_record__init() function.
>
> Update auxtrace_record__init() in arch/powerpc/util/auxtrace.c to clear
> err value in the beginning.
>
> - Clear err value in beginning of function. Any fail later will
> set appropriate return code to err.
> - Even if we haven't found any event for auxtrace, perf record
> should continue for other events. NULL return
> will indicate that there is no auxtrace record initialized.
> - Not having "err" set here will affect monitoring of other events
> also because perf record will fail seeing random value in err.
>
> With the fix,
>
> # ./perf trace record sleep 1
> [ perf record: Woken up 2 times to write data ]
> [ perf record: Captured and wrote 0.033 MB perf.data (228 samples) ]
Sounds like you need a Fixes tag.
Thanks,
Namhyung
>
> Signed-off-by: Athira Rajeev <[email protected]>
> ---
> tools/perf/arch/powerpc/util/auxtrace.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/tools/perf/arch/powerpc/util/auxtrace.c
> b/tools/perf/arch/powerpc/util/auxtrace.c
> index e39deff6c857..fe1ea4e222f3 100644
> --- a/tools/perf/arch/powerpc/util/auxtrace.c
> +++ b/tools/perf/arch/powerpc/util/auxtrace.c
> @@ -71,6 +71,19 @@ struct auxtrace_record *auxtrace_record__init(struct
> evlist *evlist,
> struct evsel *pos;
> int found = 0;
>
> + /*
> + * Assign err value to zero here. Any fail later
> + * will set appropriate return code to err.
> + * Even if we haven't found any event for auxtrace, perf
> + * record should continue for other events. NULL return
> + * will indicate that there is no auxtrace record initialized.
> + *
> + * Not having "err" set here will affect monitoring
> + * of other events also because perf record will fail seeing
> + * random value in err.
> + */
> + *err = 0;
> +
> evlist__for_each_entry(evlist, pos) {
> if (strstarts(pos->name, "vpa_dtl")) {
> found = 1;
> --
> 2.47.3
>
