Parse PERF_RECORD_SWITCH_CPU_WIDE

For now this just allows off-CPU cost analysis for
data recorded with `perf record -a --switch-events`.
In the future, we could even send the nextPrev{P,T}id
too, which would allow us to draw arrows beetween the
context switch targets.

Change-Id: Ie9b88bb9c54a3238ba8d6addd013b8419c03c42f
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

2 files changed, 35 insertions, 0 deletions

diff --git a/app/perfdata.cpp b/app/perfdata.cpp
index 2dfbc6c..27a2095 100644
--- a/app/perfdata.cpp
+++ b/app/perfdata.cpp
@@ -253,6 +253,14 @@ PerfData::ReadStatus PerfData::processEvents(QDataStream &stream)
         m_destination->contextSwitch(switchEvent);
         break;
     }
+    case PERF_RECORD_SWITCH_CPU_WIDE: {
+        PerfRecordContextSwitchCpuWide switchEvent(&m_eventHeader, sampleType, sampleIdAll);
+        stream >> switchEvent;
+        // TODO: also send prevNext{T,P}id, that would allow switch markers in the GUI to
+        //       show where a switch comes from/goes to
+        m_destination->contextSwitch(switchEvent);
+        break;
+    }
 
 #ifdef HAVE_ZSTD
     case PERF_RECORD_COMPRESSED: {
@@ -801,3 +809,13 @@ QDataStream &operator>>(QDataStream &stream, PerfRecordContextSwitch &record)
 {
     return stream >> record.m_sampleId;
 }
+
+PerfRecordContextSwitchCpuWide::PerfRecordContextSwitchCpuWide(PerfEventHeader *header, quint64 sampleType, bool sampleIdAll) :
+    PerfRecordContextSwitch(header, sampleType, sampleIdAll)
+{
+}
+
+QDataStream &operator>>(QDataStream &stream, PerfRecordContextSwitchCpuWide &record)
+{
+    return stream >> record.m_nextPrevPid >> record.m_nextPrevTid >> record.m_sampleId;
+}
diff --git a/app/perfdata.h b/app/perfdata.h
index 942de34..6b2d913 100644
--- a/app/perfdata.h
+++ b/app/perfdata.h
@@ -603,6 +603,23 @@ private:
 
 QDataStream &operator>>(QDataStream &stream, PerfRecordContextSwitch &record);
 
+class PerfRecordContextSwitchCpuWide : public PerfRecordContextSwitch
+{
+public:
+    PerfRecordContextSwitchCpuWide(PerfEventHeader *header = 0, quint64 sampleType = 0,
+                            bool sampleIdAll = false);
+
+    qint32 nextPrevPid() const { return m_nextPrevPid; }
+    qint32 nextPrevTid() const { return m_nextPrevTid; }
+
+private:
+    qint32 m_nextPrevPid;
+    qint32 m_nextPrevTid;
+    friend QDataStream &operator>>(QDataStream &stream, PerfRecordContextSwitchCpuWide &record);
+};
+
+QDataStream &operator>>(QDataStream &stream, PerfRecordContextSwitchCpuWide &record);
+
 class PerfUnwind;
 class PerfData : public QObject
 {