simpleperf: fix parsing perf.data generated by --trace-offcpu option.

When parsing perf.data generated by --trace-offcpu option, report_lib_interface
mixes all samples from cpu-cycles (or other events) and sched:sched_switch, and
uses timestamp difference as sample period. However, it still shows both event
names. This makes report_html.py generate sample table for each event name
separately. To fix this, this CL uses event name cpu-cycles for all samples.

Bug: http://b/66914187
Test: run report_html.py on perf.data generated by --trace-offcpu.
Test: run python test.py TestReportLib.test_offcpu.
Change-Id: Ic5f2e64564355f860283085fc691ead4134affa1

1 files changed, 7 insertions, 2 deletions

diff --git a/simpleperf/report_lib_interface.cpp b/simpleperf/report_lib_interface.cpp
index c7a606c9..e3af8a88 100644
--- a/simpleperf/report_lib_interface.cpp
+++ b/simpleperf/report_lib_interface.cpp
@@ -285,8 +285,13 @@ Event* ReportLib::GetEventOfCurrentSample() {
         event_attrs_.push_back(attr);
       }
     }
-    size_t attr_index =
-        record_file_reader_->GetAttrIndexOfRecord(current_record_.get());
+    size_t attr_index;
+    if (trace_offcpu_) {
+      // For trace-offcpu, we don't want to show event sched:sched_switch.
+      attr_index = 0;
+    } else {
+      attr_index = record_file_reader_->GetAttrIndexOfRecord(current_record_.get());
+    }
     current_event_.name = event_attrs_[attr_index].name.c_str();
     update_flag_ |= UPDATE_FLAG_OF_EVENT;
   }