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.
Set err to -EINVAL before invoking auxtrace_record__init() in
builtin-record.c
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) ]
Fixes: 1dbfaf94cf66 ("perf powerpc: Add basic CONFIG_AUXTRACE support for VPA
pmu on powerpc")
Reviewed-by: Adrian Hunter <[email protected]>
Signed-off-by: Athira Rajeev <[email protected]>
---
Changelog:
v4:
Added Reviewed-by from Adrian
v1 -> v2
Addressed review comment from Adrian:
- Set err to -EINVAL before invoking auxtrace_record__init() in
builtin-record.c
- Added kernel-doc to auxtrace_record__init() in tools/perf/util/auxtrace.c
Addressed review comment from Namhyung:
- Added fixes tag
tools/perf/arch/powerpc/util/auxtrace.c | 6 ++++++
tools/perf/builtin-record.c | 1 +
2 files changed, 7 insertions(+)
diff --git a/tools/perf/arch/powerpc/util/auxtrace.c
b/tools/perf/arch/powerpc/util/auxtrace.c
index e39deff6c857..4600a1661b4f 100644
--- a/tools/perf/arch/powerpc/util/auxtrace.c
+++ b/tools/perf/arch/powerpc/util/auxtrace.c
@@ -71,6 +71,12 @@ struct auxtrace_record *auxtrace_record__init(struct evlist
*evlist,
struct evsel *pos;
int found = 0;
+ /*
+ * Set err value to zero here. Any fail later
+ * will set appropriate return code to err.
+ */
+ *err = 0;
+
evlist__for_each_entry(evlist, pos) {
if (strstarts(pos->name, "vpa_dtl")) {
found = 1;
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 4a5eba498c02..708825747af5 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -865,6 +865,7 @@ static int record__auxtrace_init(struct record *rec)
}
if (!rec->itr) {
+ err = -EINVAL;
rec->itr = auxtrace_record__init(rec->evlist, &err);
if (err)
return err;
--
2.47.3
