GpuMem perfetto producer

To overcome the problem of ftrace gpumem events not emitting anything
during MEC (with apps that do launch-time allocations), this change adds
a perfetto producer to emit initial counter values at the start of a
trace, so that the visualization won't so zero usage.

Test: adb shell perfetto --query | grep gpu.
Test: Take a perfetto trace with android.gpumem enabled
Bug: 157142645
Change-Id: I5c8278754549399ffa51e6e6fc2ca69b51976cb2
Merged-In: I5c8278754549399ffa51e6e6fc2ca69b51976cb2

7 files changed, 237 insertions, 3 deletions

diff --git a/services/gpuservice/Android.bp b/services/gpuservice/Android.bp
index a75d6db11b..9a9bca1478 100644
--- a/services/gpuservice/Android.bp
+++ b/services/gpuservice/Android.bp
@@ -22,6 +22,7 @@ cc_defaults {
         "libcutils",
         "libgfxstats",
         "libgpumem",
+        "libgpumemtracer",
         "libgraphicsenv",
         "liblog",
         "libutils",
diff --git a/services/gpuservice/GpuService.cpp b/services/gpuservice/GpuService.cpp
index 84ae608148..52d5d4fc46 100644
--- a/services/gpuservice/GpuService.cpp
+++ b/services/gpuservice/GpuService.cpp
@@ -27,6 +27,7 @@
 #include <gpumem/GpuMem.h>
 #include <gpustats/GpuStats.h>
 #include <private/android_filesystem_config.h>
+#include <tracing/GpuMemTracer.h>
 #include <utils/String8.h>
 #include <utils/Trace.h>
 #include <vkjson.h>
@@ -48,8 +49,13 @@ const String16 sDump("android.permission.DUMP");
 const char* const GpuService::SERVICE_NAME = "gpu";
 
 GpuService::GpuService()
-      : mGpuMem(std::make_unique<GpuMem>()), mGpuStats(std::make_unique<GpuStats>()) {
-    std::thread asyncInitThread([this]() { mGpuMem->initialize(); });
+      : mGpuMem(std::make_shared<GpuMem>()),
+        mGpuStats(std::make_unique<GpuStats>()),
+        mGpuMemTracer(std::make_unique<GpuMemTracer>()) {
+    std::thread asyncInitThread([this]() {
+        mGpuMem->initialize();
+        mGpuMemTracer->initialize(mGpuMem);
+    });
     asyncInitThread.detach();
 };
 
diff --git a/services/gpuservice/GpuService.h b/services/gpuservice/GpuService.h
index 6797868f00..409084b656 100644
--- a/services/gpuservice/GpuService.h
+++ b/services/gpuservice/GpuService.h
@@ -30,6 +30,7 @@ namespace android {
 
 class GpuMem;
 class GpuStats;
+class GpuMemTracer;
 
 class GpuService : public BnGpuService, public PriorityDumper {
 public:
@@ -75,8 +76,9 @@ private:
     /*
      * Attributes
      */
-    std::unique_ptr<GpuMem> mGpuMem;
+    std::shared_ptr<GpuMem> mGpuMem;
     std::unique_ptr<GpuStats> mGpuStats;
+    std::unique_ptr<GpuMemTracer> mGpuMemTracer;
     std::mutex mLock;
     std::string mDeveloperDriverPath;
 };
diff --git a/services/gpuservice/gpumem/include/gpumem/GpuMem.h b/services/gpuservice/gpumem/include/gpumem/GpuMem.h
index ff8b4bc70a..49a9f95fd6 100644
--- a/services/gpuservice/gpumem/include/gpumem/GpuMem.h
+++ b/services/gpuservice/gpumem/include/gpumem/GpuMem.h
@@ -31,6 +31,29 @@ public:
     void initialize();
     // dumpsys interface
     void dump(const Vector<String16>& args, std::string* result);
+    bool isInitialized() { return mInitialized.load(); }
+
+    // Traverse the map and send each value read back to the callback function.
+    // Used for tracing.
+    template <typename lambda>
+    void traceGpuMemTotals(lambda tracerCallback) {
+        auto res = mGpuMemTotalMap.getFirstKey();
+        if (!res.ok()) return;
+        uint64_t key = res.value();
+        while (true) {
+            uint32_t gpu_id = key >> 32;
+            uint32_t pid = key;
+
+            res = mGpuMemTotalMap.readValue(key);
+            if (!res.ok()) break;
+            uint64_t size = res.value();
+
+            tracerCallback(gpu_id, pid, size);
+            res = mGpuMemTotalMap.getNextKey(key);
+            if (!res.ok()) break;
+            key = res.value();
+        }
+    }
 
 private:
     // Friend class for testing.
diff --git a/services/gpuservice/tracing/Android.bp b/services/gpuservice/tracing/Android.bp
new file mode 100644
index 0000000000..919fed3cec
--- /dev/null
+++ b/services/gpuservice/tracing/Android.bp
@@ -0,0 +1,41 @@
+// Copyright 2020 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+cc_library_shared {
+    name: "libgpumemtracer",
+    srcs: [
+        "GpuMemTracer.cpp",
+    ],
+    shared_libs: [
+        "libgpumem",
+        "libbase",
+        "liblog",
+        "libutils",
+    ],
+    static_libs: [
+        "libperfetto_client_experimental",
+    ],
+    export_include_dirs: ["include"],
+    export_static_lib_headers: [
+        "libperfetto_client_experimental",
+    ],
+    cppflags: [
+        "-Wall",
+        "-Werror",
+        "-Wformat",
+        "-Wthread-safety",
+        "-Wunused",
+        "-Wunreachable-code",
+    ],
+}
diff --git a/services/gpuservice/tracing/GpuMemTracer.cpp b/services/gpuservice/tracing/GpuMemTracer.cpp
new file mode 100644
index 0000000000..c9bfa57a30
--- /dev/null
+++ b/services/gpuservice/tracing/GpuMemTracer.cpp
@@ -0,0 +1,101 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#undef LOG_TAG
+#define LOG_TAG "GpuMemTracer"
+#define ATRACE_TAG ATRACE_TAG_GRAPHICS
+
+#include "tracing/GpuMemTracer.h"
+
+#include <gpumem/GpuMem.h>
+#include <perfetto/trace/android/gpu_mem_event.pbzero.h>
+#include <unistd.h>
+#include <utils/Timers.h>
+
+#include <algorithm>
+#include <thread>
+
+PERFETTO_DEFINE_DATA_SOURCE_STATIC_MEMBERS(android::GpuMemTracer::GpuMemDataSource);
+
+namespace android {
+
+std::mutex GpuMemTracer::sTraceMutex;
+std::condition_variable GpuMemTracer::sCondition;
+bool GpuMemTracer::sTraceStarted;
+
+void GpuMemTracer::initialize(std::shared_ptr<GpuMem> gpuMem) {
+    if (!gpuMem->isInitialized()) {
+        ALOGE("Cannot initialize GpuMemTracer before GpuMem");
+        return;
+    }
+    mGpuMem = gpuMem;
+    perfetto::TracingInitArgs args;
+    args.backends = perfetto::kSystemBackend;
+    // TODO(b/160016498): Find a better way to wait for traced
+    // Sleep for 30 seconds to make sure the data source is registered only
+    // after traced starts.
+    sleep(30);
+    perfetto::Tracing::Initialize(args);
+    registerDataSource();
+    std::thread tracerThread(&GpuMemTracer::threadLoop, this);
+    pthread_setname_np(tracerThread.native_handle(), "GpuMemTracerThread");
+    tracerThread.detach();
+}
+
+void GpuMemTracer::registerDataSource() {
+    perfetto::DataSourceDescriptor dsd;
+    dsd.set_name(kGpuMemDataSource);
+    GpuMemDataSource::Register(dsd);
+}
+
+void GpuMemTracer::threadLoop() {
+    while (true) {
+        {
+            std::unique_lock<std::mutex> lock(GpuMemTracer::sTraceMutex);
+            while (!sTraceStarted) {
+                sCondition.wait(lock);
+            }
+        }
+        traceInitialCounters();
+        {
+            std::lock_guard<std::mutex> lock(GpuMemTracer::sTraceMutex);
+            sTraceStarted = false;
+        }
+    }
+}
+
+void GpuMemTracer::traceInitialCounters() {
+    if (!mGpuMem->isInitialized()) {
+        // This should never happen.
+        ALOGE("Cannot trace without GpuMem initialization");
+        return;
+    }
+    mGpuMem->traceGpuMemTotals([](uint32_t gpuId, uint32_t pid, uint64_t size) {
+        GpuMemDataSource::Trace([&](GpuMemDataSource::TraceContext ctx) {
+            auto packet = ctx.NewTracePacket();
+            packet->set_timestamp(systemTime());
+            auto* event = packet->set_gpu_mem_total_event();
+            event->set_gpu_id(gpuId);
+            event->set_pid(pid);
+            event->set_size(size);
+        });
+    });
+    // Flush the TraceContext. The last packet in the above loop will go
+    // missing without this flush.
+    GpuMemDataSource::Trace([](GpuMemDataSource::TraceContext ctx) { ctx.Flush(); });
+}
+
+} // namespace android
diff --git a/services/gpuservice/tracing/include/tracing/GpuMemTracer.h b/services/gpuservice/tracing/include/tracing/GpuMemTracer.h
new file mode 100644
index 0000000000..40deb4c212
--- /dev/null
+++ b/services/gpuservice/tracing/include/tracing/GpuMemTracer.h
@@ -0,0 +1,60 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <perfetto/tracing.h>
+
+#include <mutex>
+
+namespace android {
+
+class GpuMem;
+
+class GpuMemTracer {
+public:
+    class GpuMemDataSource : public perfetto::DataSource<GpuMemDataSource> {
+        virtual void OnSetup(const SetupArgs&) override{};
+        virtual void OnStart(const StartArgs&) override {
+            std::unique_lock<std::mutex> lock(GpuMemTracer::sTraceMutex);
+            sTraceStarted = true;
+            sCondition.notify_all();
+        }
+        virtual void OnStop(const StopArgs&) override{};
+    };
+
+    ~GpuMemTracer() = default;
+
+    // Sets up the perfetto tracing backend and data source.
+    void initialize(std::shared_ptr<GpuMem>);
+    // Registers the data source with the perfetto backend. Called as part of initialize()
+    // and should not be called manually outside of tests. Public to allow for substituting a
+    // perfetto::kInProcessBackend in tests.
+    void registerDataSource();
+
+    static constexpr char kGpuMemDataSource[] = "android.gpu.memory";
+    static std::condition_variable sCondition;
+    static std::mutex sTraceMutex;
+    static bool sTraceStarted;
+
+private:
+    void traceInitialCounters();
+    void threadLoop();
+
+    std::shared_ptr<GpuMem> mGpuMem;
+};
+
+} // namespace android