sf-latency: Wait on fence after each drawLayers call
Bug: 193240340
Test: this
Previously, the benchmark simply passed the fence to the next call,
meaning that the next drawLayers could start before the GPU was
finished. Explicitly wait for it inside the benchmark, so that we'll
time both CPU and GPU work.
Add comments describing such.
Change-Id: I7f34636d6b3701b71eaa8d8435e947e258d2fa67
diff --git a/libs/renderengine/benchmark/RenderEngineBench.cpp b/libs/renderengine/benchmark/RenderEngineBench.cpp
index 719b855..9ee7e4d 100644
--- a/libs/renderengine/benchmark/RenderEngineBench.cpp
+++ b/libs/renderengine/benchmark/RenderEngineBench.cpp
@@ -111,8 +111,7 @@
return RenderEngine::create(args);
}
-static std::shared_ptr<ExternalTexture> allocateBuffer(RenderEngine& re,
- uint32_t width,
+static std::shared_ptr<ExternalTexture> allocateBuffer(RenderEngine& re, uint32_t width,
uint32_t height,
uint64_t extraUsageFlags = 0,
std::string name = "output") {
@@ -160,11 +159,21 @@
auto [status, drawFence] =
re.drawLayers(display, layers, texture, kUseFrameBufferCache, base::unique_fd()).get();
- sp<Fence> waitFence = new Fence(std::move(drawFence));
+ sp<Fence> waitFence = sp<Fence>::make(std::move(drawFence));
waitFence->waitForever(LOG_TAG);
return texture;
}
+/**
+ * Helper for timing calls to drawLayers.
+ *
+ * Caller needs to create RenderEngine and the LayerSettings, and this takes
+ * care of setting up the display, starting and stopping the timer, calling
+ * drawLayers, and saving (if --save is used).
+ *
+ * This times both the CPU and GPU work initiated by drawLayers. All work done
+ * outside of the for loop is excluded from the timing measurements.
+ */
static void benchDrawLayers(RenderEngine& re, const std::vector<LayerSettings>& layers,
benchmark::State& benchState, const char* saveFileName) {
auto [width, height] = getDisplaySize();
@@ -177,18 +186,16 @@
.maxLuminance = 500,
};
- base::unique_fd fence;
+ // This loop starts and stops the timer.
for (auto _ : benchState) {
- auto [status, drawFence] =
- re.drawLayers(display, layers, outputBuffer, kUseFrameBufferCache, std::move(fence))
- .get();
- fence = std::move(drawFence);
+ auto [status, drawFence] = re.drawLayers(display, layers, outputBuffer,
+ kUseFrameBufferCache, base::unique_fd())
+ .get();
+ sp<Fence> waitFence = sp<Fence>::make(std::move(drawFence));
+ waitFence->waitForever(LOG_TAG);
}
if (renderenginebench::save() && saveFileName) {
- sp<Fence> waitFence = new Fence(std::move(fence));
- waitFence->waitForever(LOG_TAG);
-
// Copy to a CPU-accessible buffer so we can encode it.
outputBuffer = copyBuffer(re, outputBuffer, GRALLOC_USAGE_SW_READ_OFTEN, "to_encode");
@@ -209,8 +216,8 @@
// Initially use cpu access so we can decode into it with AImageDecoder.
auto [width, height] = getDisplaySize();
- auto srcBuffer = allocateBuffer(*re, width, height, GRALLOC_USAGE_SW_WRITE_OFTEN,
- "decoded_source");
+ auto srcBuffer =
+ allocateBuffer(*re, width, height, GRALLOC_USAGE_SW_WRITE_OFTEN, "decoded_source");
{
std::string srcImage = base::GetExecutableDirectory();
srcImage.append("/resources/homescreen.png");