Cycles: add time statistics to scene update

Gathers information for time spent in the various managers or object (Film, Camera, etc.) being updated in Scene::device_update.

The stats include the total time spent in the device_update methods as well as time spent in subroutines (e.g. bvh build, displacement, etc.).

This does not qualify as a full blown profiler, but is useful to identify potential bottleneck areas.

The stats can be enabled and printed by passing `--cycles-print-stats` on the command line to Cycles, or `-- --cycles-print-stats` to Blender.

Reviewed By: brecht

Maniphest Tasks: T79174

Differential Revision: https://developer.blender.org/D8596

1 files changed, 7 insertions, 0 deletions

diff --git a/intern/cycles/render/light.cpp b/intern/cycles/render/light.cpp
index 5f586f98b13..100530ffba6 100644
--- a/intern/cycles/render/light.cpp
+++ b/intern/cycles/render/light.cpp
@@ -25,6 +25,7 @@
 #include "render/object.h"
 #include "render/scene.h"
 #include "render/shader.h"
+#include "render/stats.h"
 
 #include "util/util_foreach.h"
 #include "util/util_hash.h"
@@ -961,6 +962,12 @@ void LightManager::device_update(Device *device,
   if (!need_update)
     return;
 
+  scoped_callback_timer timer([scene](double time) {
+    if (scene->update_stats) {
+      scene->update_stats->light.times.add_entry({"device_update", time});
+    }
+  });
+
   VLOG(1) << "Total " << scene->lights.size() << " lights.";
 
   /* Detect which lights are enabled, also determins if we need to update the background. */