Add i915-perf sampling support

In addition to the normal ftrace recording, the scripts will use the
i915-perf-recorder tool from IGT to record GPU generated performance
data on Intel platforms.

Before starting the recording, set the following variable

  export USE_I915_PERF=1

You can also select what metric set you want to use. This will affect
what kind of GPU performance data is recorded. A list of metric set is
available from the following command :

  i915-perf-recorder -m list

You can list counters recorded for each metric set along with their
description :

  i915-perf-recorder -m RenderBasic -C

then

  ./trace-cmd-start-tracing.sh

sample/trace-cmd-capture.sh

@@ -19,6 +19,11 @@ CMD="trace-cmd stop"
 echo ${CMD}
 $CMD
 
+# Extract i915-perf trace
+CMD="i915-perf-control -d trace_${DATE}.i915-dat"
+echo ${CMD}
+$CMD
+
 # Extract trace
 CMD="trace-cmd extract -k -o trace_${DATE}.dat"
 echo ${CMD}

sample/trace-cmd-setup.sh

@@ -83,6 +83,9 @@ else
     ROOT_CMDS+="chmod 0222 \"${TRACEFS}/trace_marker\"\n"
 fi
 
+# Enable i915-perf to collect GPU data.
+ROOT_CMDS+="sysctl dev.i915.perf_stream_paranoid=0"
+
 if [ -z "${ROOT_CMDS}" ]; then
     :
 else
@@ -134,4 +137,3 @@ else
 fi
 
 spewTraceStatus
-

sample/trace-cmd-start-tracing.sh

@@ -12,6 +12,13 @@ if [ ! -u "${TRACECMD}" ]; then
     exit -1
 fi
 
+if [ "${USE_I915_PERF}" ]; then
+    if [ -z "${I915_PERF_METRIC}" ]; then
+        echo "WARNING: Missing I915_PERF_METRIC value. Using default value 'RenderBasic'."
+        I915_PERF_METRIC="RenderBasic"
+    fi
+fi
+
 EVENTS=
 
 # https://github.com/mikesart/gpuvis/wiki/TechDocs-Linux-Scheduler
@@ -63,10 +70,22 @@ CMD="trace-cmd reset"
 echo $CMD
 $CMD
 
+CLOCK=mono
+
 echo
-CMD="trace-cmd start -C mono -b 8000 -D -i ${EVENTS}"
+CMD="trace-cmd start -C ${CLOCK} -b 8000 -D -i ${EVENTS}"
 echo $CMD
 $CMD
 
+if [ -e /tmp/.i915-perf-record ]; then
+   CMD="i915-perf-control -q"
+   echo $CMD
+   $CMD
+fi
+
+CMD="i915-perf-recorder -m ${I915_PERF_METRIC} -s 8000 -k ${CLOCK}"
+echo $CMD
+$CMD &
+
 echo
 ./trace-cmd-status.sh

sample/trace-cmd-stop-tracing.sh

@@ -8,4 +8,10 @@ CMD="trace-cmd snapshot -f"
 echo $CMD
 $CMD
 
+if [ "${USE_I915_PERF} " ]; then
+    CMD="i915-perf-control -q"
+    echo $CMD
+    $CMD
+fi
+
 ./trace-cmd-status.sh