Merge pull request #6162 from degasus/no_spin_loops

video_core: Avoid spin loops.
This commit is contained in:
bunnei 2021-04-09 11:52:18 -07:00 committed by GitHub
commit d6e5e053a6
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6 changed files with 64 additions and 33 deletions

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@ -83,11 +83,15 @@ public:
return true;
}
T PopWait() {
void Wait() {
if (Empty()) {
std::unique_lock lock{cv_mutex};
cv.wait(lock, [this]() { return !Empty(); });
}
}
T PopWait() {
Wait();
T t;
Pop(t);
return t;
@ -156,6 +160,10 @@ public:
return spsc_queue.Pop(t);
}
void Wait() {
spsc_queue.Wait();
}
T PopWait() {
return spsc_queue.PopWait();
}

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@ -296,7 +296,7 @@ struct System::Impl {
exit_lock = false;
if (gpu_core) {
gpu_core->WaitIdle();
gpu_core->ShutDown();
}
services.reset();

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@ -517,8 +517,8 @@ void GPU::TriggerCpuInterrupt(const u32 syncpoint_id, const u32 value) const {
interrupt_manager.GPUInterruptSyncpt(syncpoint_id, value);
}
void GPU::WaitIdle() const {
gpu_thread.WaitIdle();
void GPU::ShutDown() {
gpu_thread.ShutDown();
}
void GPU::OnCommandListEnd() {

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@ -219,8 +219,8 @@ public:
return *shader_notify;
}
// Waits for the GPU to finish working
void WaitIdle() const;
// Stops the GPU execution and waits for the GPU to finish working
void ShutDown();
/// Allows the CPU/NvFlinger to wait on the GPU before presenting a frame.
void WaitFence(u32 syncpoint_id, u32 value);

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@ -29,8 +29,7 @@ static void RunThread(Core::System& system, VideoCore::RendererBase& renderer,
system.RegisterHostThread();
// Wait for first GPU command before acquiring the window context
while (state.queue.Empty())
;
state.queue.Wait();
// If emulation was stopped during disk shader loading, abort before trying to acquire context
if (!state.is_running) {
@ -57,11 +56,17 @@ static void RunThread(Core::System& system, VideoCore::RendererBase& renderer,
} else if (const auto* invalidate = std::get_if<InvalidateRegionCommand>(&next.data)) {
rasterizer->OnCPUWrite(invalidate->addr, invalidate->size);
} else if (std::holds_alternative<EndProcessingCommand>(next.data)) {
return;
ASSERT(state.is_running == false);
} else {
UNREACHABLE();
}
state.signaled_fence.store(next.fence);
if (next.block) {
// We have to lock the write_lock to ensure that the condition_variable wait not get a
// race between the check and the lock itself.
std::lock_guard lk(state.write_lock);
state.cv.notify_all();
}
}
}
@ -69,13 +74,7 @@ ThreadManager::ThreadManager(Core::System& system_, bool is_async_)
: system{system_}, is_async{is_async_} {}
ThreadManager::~ThreadManager() {
if (!thread.joinable()) {
return;
}
// Notify GPU thread that a shutdown is pending
PushCommand(EndProcessingCommand());
thread.join();
ShutDown();
}
void ThreadManager::StartThread(VideoCore::RendererBase& renderer,
@ -112,9 +111,8 @@ void ThreadManager::FlushRegion(VAddr addr, u64 size) {
case Settings::GPUAccuracy::Extreme: {
auto& gpu = system.GPU();
u64 fence = gpu.RequestFlush(addr, size);
PushCommand(GPUTickCommand());
while (fence > gpu.CurrentFlushRequestFence()) {
}
PushCommand(GPUTickCommand(), true);
ASSERT(fence <= gpu.CurrentFlushRequestFence());
break;
}
default:
@ -131,23 +129,45 @@ void ThreadManager::FlushAndInvalidateRegion(VAddr addr, u64 size) {
rasterizer->OnCPUWrite(addr, size);
}
void ThreadManager::WaitIdle() const {
while (state.last_fence > state.signaled_fence.load(std::memory_order_relaxed) &&
system.IsPoweredOn()) {
void ThreadManager::ShutDown() {
if (!state.is_running) {
return;
}
{
std::lock_guard lk(state.write_lock);
state.is_running = false;
state.cv.notify_all();
}
if (!thread.joinable()) {
return;
}
// Notify GPU thread that a shutdown is pending
PushCommand(EndProcessingCommand());
thread.join();
}
void ThreadManager::OnCommandListEnd() {
PushCommand(OnCommandListEndCommand());
}
u64 ThreadManager::PushCommand(CommandData&& command_data) {
const u64 fence{++state.last_fence};
state.queue.Push(CommandDataContainer(std::move(command_data), fence));
u64 ThreadManager::PushCommand(CommandData&& command_data, bool block) {
if (!is_async) {
// In synchronous GPU mode, block the caller until the command has executed
WaitIdle();
block = true;
}
std::unique_lock lk(state.write_lock);
const u64 fence{++state.last_fence};
state.queue.Push(CommandDataContainer(std::move(command_data), fence, block));
if (block) {
state.cv.wait(lk, [this, fence] {
return fence <= state.signaled_fence.load(std::memory_order_relaxed) ||
!state.is_running;
});
}
return fence;

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@ -90,21 +90,24 @@ using CommandData =
struct CommandDataContainer {
CommandDataContainer() = default;
explicit CommandDataContainer(CommandData&& data_, u64 next_fence_)
: data{std::move(data_)}, fence{next_fence_} {}
explicit CommandDataContainer(CommandData&& data_, u64 next_fence_, bool block_)
: data{std::move(data_)}, fence{next_fence_}, block(block_) {}
CommandData data;
u64 fence{};
bool block{};
};
/// Struct used to synchronize the GPU thread
struct SynchState final {
std::atomic_bool is_running{true};
using CommandQueue = Common::MPSCQueue<CommandDataContainer>;
using CommandQueue = Common::SPSCQueue<CommandDataContainer>;
std::mutex write_lock;
CommandQueue queue;
u64 last_fence{};
std::atomic<u64> signaled_fence{};
std::condition_variable cv;
};
/// Class used to manage the GPU thread
@ -132,14 +135,14 @@ public:
/// Notify rasterizer that any caches of the specified region should be flushed and invalidated
void FlushAndInvalidateRegion(VAddr addr, u64 size);
// Wait until the gpu thread is idle.
void WaitIdle() const;
// Stops the GPU execution and waits for the GPU to finish working
void ShutDown();
void OnCommandListEnd();
private:
/// Pushes a command to be executed by the GPU thread
u64 PushCommand(CommandData&& command_data);
u64 PushCommand(CommandData&& command_data, bool block = false);
Core::System& system;
const bool is_async;