[PATCH] perf tools: intel-pt: fix endless record after being terminated

From: Wei Li
Date: Thu Jan 02 2020 - 02:27:58 EST


In __cmd_record(), when receiving SIGINT(ctrl + c), a done flag will
be set and the event list will be disabled by evlist__disable() once.

While in auxtrace_record.read_finish(), the related events will be
enabled again, if they are continuous, the recording seems to be endless.

If the intel_pt event is disabled, we don't enable it again here.

Before the patch:
huawei@huawei-2288H-V5:~/linux-5.5-rc4/tools/perf$ ./perf record -e \
intel_pt//u -p 46803
^C^C^C^C^C^C

After the patch:
huawei@huawei-2288H-V5:~/linux-5.5-rc4/tools/perf$ ./perf record -e \
intel_pt//u -p 48591
^C[ perf record: Woken up 0 times to write data ]
Warning:
AUX data lost 504 times out of 4816!

[ perf record: Captured and wrote 2024.405 MB perf.data ]

Signed-off-by: Wei Li <liwei391@xxxxxxxxxx>
---
tools/perf/arch/x86/util/intel-pt.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/tools/perf/arch/x86/util/intel-pt.c b/tools/perf/arch/x86/util/intel-pt.c
index 20df442fdf36..1e96afcd8646 100644
--- a/tools/perf/arch/x86/util/intel-pt.c
+++ b/tools/perf/arch/x86/util/intel-pt.c
@@ -1173,9 +1173,13 @@ static int intel_pt_read_finish(struct auxtrace_record *itr, int idx)
struct evsel *evsel;

evlist__for_each_entry(ptr->evlist, evsel) {
- if (evsel->core.attr.type == ptr->intel_pt_pmu->type)
- return perf_evlist__enable_event_idx(ptr->evlist, evsel,
- idx);
+ if (evsel->core.attr.type == ptr->intel_pt_pmu->type) {
+ if (evsel->disabled)
+ return 0;
+ else
+ return perf_evlist__enable_event_idx(
+ ptr->evlist, evsel, idx);
+ }
}
return -EINVAL;
}
--
2.17.1