From 4555b637500daeb26f556113656fc3d242e60872 Mon Sep 17 00:00:00 2001
From: bunnei <bunneidev@gmail.com>
Date: Sat, 30 Mar 2019 20:08:09 -0400
Subject: [PATCH] gpu_thread: Improve synchronization by using CoreTiming.
---
src/video_core/gpu_asynch.cpp | 2 +-
src/video_core/gpu_thread.cpp | 43 ++++++++++++++++-----
src/video_core/gpu_thread.h | 73 +++++++++++++++--------------------
3 files changed, 66 insertions(+), 52 deletions(-)
diff --git a/src/video_core/gpu_asynch.cpp b/src/video_core/gpu_asynch.cpp
index 8b355cf7b..db507cf04 100644
--- a/src/video_core/gpu_asynch.cpp
+++ b/src/video_core/gpu_asynch.cpp
@@ -9,7 +9,7 @@
namespace VideoCommon {
GPUAsynch::GPUAsynch(Core::System& system, VideoCore::RendererBase& renderer)
- : Tegra::GPU(system, renderer), gpu_thread{renderer, *dma_pusher} {}
+ : Tegra::GPU(system, renderer), gpu_thread{system, renderer, *dma_pusher} {}
GPUAsynch::~GPUAsynch() = default;
diff --git a/src/video_core/gpu_thread.cpp b/src/video_core/gpu_thread.cpp
index c5dc199c5..23f9bd422 100644
--- a/src/video_core/gpu_thread.cpp
+++ b/src/video_core/gpu_thread.cpp
@@ -4,6 +4,9 @@
#include "common/assert.h"
#include "common/microprofile.h"
+#include "core/core.h"
+#include "core/core_timing.h"
+#include "core/core_timing_util.h"
#include "core/frontend/scope_acquire_window_context.h"
#include "video_core/dma_pusher.h"
#include "video_core/gpu.h"
@@ -36,7 +39,6 @@ static void RunThread(VideoCore::RendererBase& renderer, Tegra::DmaPusher& dma_p
dma_pusher.Push(std::move(submit_list->entries));
dma_pusher.DispatchCalls();
} else if (const auto data = std::get_if<SwapBuffersCommand>(&next.data)) {
- state.DecrementFramesCounter();
renderer.SwapBuffers(std::move(data->framebuffer));
} else if (const auto data = std::get_if<FlushRegionCommand>(&next.data)) {
renderer.Rasterizer().FlushRegion(data->addr, data->size);
@@ -47,13 +49,18 @@ static void RunThread(VideoCore::RendererBase& renderer, Tegra::DmaPusher& dma_p
} else {
UNREACHABLE();
}
+ state.signaled_fence = next.fence;
+ state.TrySynchronize();
}
}
}
-ThreadManager::ThreadManager(VideoCore::RendererBase& renderer, Tegra::DmaPusher& dma_pusher)
- : renderer{renderer}, thread{RunThread, std::ref(renderer), std::ref(dma_pusher),
- std::ref(state)} {}
+ThreadManager::ThreadManager(Core::System& system, VideoCore::RendererBase& renderer,
+ Tegra::DmaPusher& dma_pusher)
+ : system{system}, thread{RunThread, std::ref(renderer), std::ref(dma_pusher), std::ref(state)} {
+ synchronization_event = system.CoreTiming().RegisterEvent(
+ "GPUThreadSynch", [this](u64 fence, int) { state.WaitForSynchronization(fence); });
+}
ThreadManager::~ThreadManager() {
// Notify GPU thread that a shutdown is pending
@@ -62,14 +69,14 @@ ThreadManager::~ThreadManager() {
}
void ThreadManager::SubmitList(Tegra::CommandList&& entries) {
- PushCommand(SubmitListCommand(std::move(entries)));
+ const u64 fence{PushCommand(SubmitListCommand(std::move(entries)))};
+ const s64 synchronization_ticks{Core::Timing::usToCycles(9000)};
+ system.CoreTiming().ScheduleEvent(synchronization_ticks, synchronization_event, fence);
}
void ThreadManager::SwapBuffers(
std::optional<std::reference_wrapper<const Tegra::FramebufferConfig>> framebuffer) {
- state.IncrementFramesCounter();
PushCommand(SwapBuffersCommand(std::move(framebuffer)));
- state.WaitForFrames();
}
void ThreadManager::FlushRegion(CacheAddr addr, u64 size) {
@@ -79,7 +86,7 @@ void ThreadManager::FlushRegion(CacheAddr addr, u64 size) {
void ThreadManager::InvalidateRegion(CacheAddr addr, u64 size) {
if (state.queue.Empty()) {
// It's quicker to invalidate a single region on the CPU if the queue is already empty
- renderer.Rasterizer().InvalidateRegion(addr, size);
+ system.Renderer().Rasterizer().InvalidateRegion(addr, size);
} else {
PushCommand(InvalidateRegionCommand(addr, size));
}
@@ -90,9 +97,25 @@ void ThreadManager::FlushAndInvalidateRegion(CacheAddr addr, u64 size) {
InvalidateRegion(addr, size);
}
-void ThreadManager::PushCommand(CommandData&& command_data) {
- state.queue.Push(CommandDataContainer(std::move(command_data)));
+u64 ThreadManager::PushCommand(CommandData&& command_data) {
+ const u64 fence{++state.last_fence};
+ state.queue.Push(CommandDataContainer(std::move(command_data), fence));
state.SignalCommands();
+ return fence;
+}
+
+MICROPROFILE_DEFINE(GPU_wait, "GPU", "Wait for the GPU", MP_RGB(128, 128, 192));
+void SynchState::WaitForSynchronization(u64 fence) {
+ if (signaled_fence >= fence) {
+ return;
+ }
+
+ // Wait for the GPU to be idle (all commands to be executed)
+ {
+ MICROPROFILE_SCOPE(GPU_wait);
+ std::unique_lock<std::mutex> lock{synchronization_mutex};
+ synchronization_condition.wait(lock, [this, fence] { return signaled_fence >= fence; });
+ }
}
} // namespace VideoCommon::GPUThread
diff --git a/src/video_core/gpu_thread.h b/src/video_core/gpu_thread.h
index 70acb2e79..62bcea5bb 100644
--- a/src/video_core/gpu_thread.h
+++ b/src/video_core/gpu_thread.h
@@ -19,9 +19,12 @@ struct FramebufferConfig;
class DmaPusher;
} // namespace Tegra
-namespace VideoCore {
-class RendererBase;
-} // namespace VideoCore
+namespace Core {
+class System;
+namespace Timing {
+struct EventType;
+} // namespace Timing
+} // namespace Core
namespace VideoCommon::GPUThread {
@@ -75,63 +78,47 @@ using CommandData =
struct CommandDataContainer {
CommandDataContainer() = default;
- CommandDataContainer(CommandData&& data) : data{std::move(data)} {}
+ CommandDataContainer(CommandData&& data, u64 next_fence)
+ : data{std::move(data)}, fence{next_fence} {}
CommandDataContainer& operator=(const CommandDataContainer& t) {
data = std::move(t.data);
+ fence = t.fence;
return *this;
}
CommandData data;
+ u64 fence{};
};
/// Struct used to synchronize the GPU thread
struct SynchState final {
std::atomic_bool is_running{true};
std::atomic_int queued_frame_count{};
- std::mutex frames_mutex;
+ std::mutex synchronization_mutex;
std::mutex commands_mutex;
std::condition_variable commands_condition;
- std::condition_variable frames_condition;
+ std::condition_variable synchronization_condition;
- void IncrementFramesCounter() {
- std::lock_guard lock{frames_mutex};
- ++queued_frame_count;
+ /// Returns true if the gap in GPU commands is small enough that we can consider the CPU and GPU
+ /// synchronized. This is entirely empirical.
+ bool IsSynchronized() const {
+ constexpr std::size_t max_queue_gap{5};
+ return queue.Size() <= max_queue_gap;
}
- void DecrementFramesCounter() {
- {
- std::lock_guard lock{frames_mutex};
- --queued_frame_count;
-
- if (queued_frame_count) {
- return;
- }
- }
- frames_condition.notify_one();
- }
-
- void WaitForFrames() {
- {
- std::lock_guard lock{frames_mutex};
- if (!queued_frame_count) {
- return;
- }
- }
-
- // Wait for the GPU to be idle (all commands to be executed)
- {
- std::unique_lock lock{frames_mutex};
- frames_condition.wait(lock, [this] { return !queued_frame_count; });
+ void TrySynchronize() {
+ if (IsSynchronized()) {
+ std::lock_guard<std::mutex> lock{synchronization_mutex};
+ synchronization_condition.notify_one();
}
}
+ void WaitForSynchronization(u64 fence);
+
void SignalCommands() {
- {
- std::unique_lock lock{commands_mutex};
- if (queue.Empty()) {
- return;
- }
+ if (queue.Empty()) {
+ return;
}
commands_condition.notify_one();
@@ -144,12 +131,15 @@ struct SynchState final {
using CommandQueue = Common::SPSCQueue<CommandDataContainer>;
CommandQueue queue;
+ u64 last_fence{};
+ std::atomic<u64> signaled_fence{};
};
/// Class used to manage the GPU thread
class ThreadManager final {
public:
- explicit ThreadManager(VideoCore::RendererBase& renderer, Tegra::DmaPusher& dma_pusher);
+ explicit ThreadManager(Core::System& system, VideoCore::RendererBase& renderer,
+ Tegra::DmaPusher& dma_pusher);
~ThreadManager();
/// Push GPU command entries to be processed
@@ -170,11 +160,12 @@ public:
private:
/// Pushes a command to be executed by the GPU thread
- void PushCommand(CommandData&& command_data);
+ u64 PushCommand(CommandData&& command_data);
private:
SynchState state;
- VideoCore::RendererBase& renderer;
+ Core::System& system;
+ Core::Timing::EventType* synchronization_event{};
std::thread thread;
std::thread::id thread_id;
};