[D3D12] Submit command lists on primary buffer end

src/xenia/gpu/command_processor.cc

@@ -464,6 +464,8 @@ uint32_t CommandProcessor::ExecutePrimaryBuffer(uint32_t read_index,
     }
   } while (reader.read_count());
 
+  OnPrimaryBufferEnd();
+
   trace_writer_.WritePrimaryBufferEnd();
 
   return write_index;

src/xenia/gpu/command_processor.h

@@ -177,6 +177,7 @@ class CommandProcessor {
                            uint32_t frontbuffer_height) = 0;
 
   uint32_t ExecutePrimaryBuffer(uint32_t start_index, uint32_t end_index);
+  virtual void OnPrimaryBufferEnd() {}
   void ExecuteIndirectBuffer(uint32_t ptr, uint32_t length);
   bool ExecutePacket(RingBuffer* reader);
   bool ExecutePacketType0(RingBuffer* reader, uint32_t packet);

src/xenia/gpu/d3d12/d3d12_command_processor.cc

@@ -50,6 +50,10 @@ DEFINE_bool(d3d12_ssaa_custom_sample_positions, false,
             "path where available instead of centers (experimental, not very "
             "high-quality).",
             "D3D12");
+DEFINE_bool(d3d12_submit_on_primary_buffer_end, true,
+            "Submit the command list when a PM4 primary buffer ends if it's "
+            "possible to submit immediately to try to reduce frame latency.",
+            "D3D12");
 
 namespace xe {
 namespace gpu {
@@ -1222,6 +1226,13 @@ void D3D12CommandProcessor::PerformSwap(uint32_t frontbuffer_ptr,
   EndSubmission(true);
 }
 
+void D3D12CommandProcessor::OnPrimaryBufferEnd() {
+  if (cvars::d3d12_submit_on_primary_buffer_end && submission_open_ &&
+      CanEndSubmissionImmediately()) {
+    EndSubmission(false);
+  }
+}
+
 Shader* D3D12CommandProcessor::LoadShader(ShaderType shader_type,
                                           uint32_t guest_address,
                                           const uint32_t* host_address,
@@ -2073,6 +2084,10 @@ bool D3D12CommandProcessor::EndSubmission(bool is_swap) {
   return true;
 }
 
+bool D3D12CommandProcessor::CanEndSubmissionImmediately() const {
+  return !submission_open_ || !pipeline_cache_->IsCreatingPipelines();
+}
+
 void D3D12CommandProcessor::AwaitAllSubmissionsCompletion() {
   // May be called if shutting down without everything set up.
   if ((submission_completed_ + 1) >= submission_current_ ||

src/xenia/gpu/d3d12/d3d12_command_processor.h

@@ -164,6 +164,8 @@ class D3D12CommandProcessor : public CommandProcessor {
   void PerformSwap(uint32_t frontbuffer_ptr, uint32_t frontbuffer_width,
                    uint32_t frontbuffer_height) override;
 
+  void OnPrimaryBufferEnd() override;
+
   Shader* LoadShader(ShaderType shader_type, uint32_t guest_address,
                      const uint32_t* host_address,
                      uint32_t dword_count) override;
@@ -235,6 +237,11 @@ class D3D12CommandProcessor : public CommandProcessor {
   // clearing and stopping capturing. Returns whether the submission was done
   // successfully, if it has failed, leaves it open.
   bool EndSubmission(bool is_swap);
+  // Checks if ending a submission right now would not cause potentially more
+  // delay than it would reduce by making the GPU start working earlier - such
+  // as when there are unfinished graphics pipeline state creation requests that
+  // would need to be fulfilled before actually submitting the command list.
+  bool CanEndSubmissionImmediately() const;
   void AwaitAllSubmissionsCompletion();
   // Need to await submission completion before calling.
   void ClearCommandAllocatorCache();

src/xenia/gpu/d3d12/pipeline_cache.cc

@@ -172,6 +172,14 @@ void PipelineCache::EndSubmission() {
   }
 }
 
+bool PipelineCache::IsCreatingPipelines() {
+  if (creation_threads_.empty()) {
+    return false;
+  }
+  std::lock_guard<std::mutex> lock(creation_request_lock_);
+  return !creation_queue_.empty() || creation_threads_busy_ != 0;
+}
+
 D3D12Shader* PipelineCache::LoadShader(ShaderType shader_type,
                                        uint32_t guest_address,
                                        const uint32_t* host_address,

src/xenia/gpu/d3d12/pipeline_cache.h

@@ -43,6 +43,7 @@ class PipelineCache {
   void ClearCache();
 
   void EndSubmission();
+  bool IsCreatingPipelines();
 
   D3D12Shader* LoadShader(ShaderType shader_type, uint32_t guest_address,
                           const uint32_t* host_address, uint32_t dword_count);