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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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Athira Rajeev
789d22d778
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: 1dbfaf94cf ("perf powerpc: Add basic CONFIG_AUXTRACE support for VPA pmu on powerpc")
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.ibm.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Athira Rajeev <atrajeev@linux.ibm.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Shivani Nittor <shivani@linux.ibm.com>
Cc: Tanushree Shah <tanushree.shah@ibm.com>
Cc: Tejas Manhas <tejas.manhas1@ibm.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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