core: log rolling fps every 30s and a session average at shutdown

Every -logfile / stdout-captured run now leaves a durable framerate
record: a "PerfLog:" line every ~30s (rolling fps + EE/GS/VU/GPU thread
utilization + frame number, so warmup separates from steady state) and a
"PerfLog session:" whole-session average at VM shutdown. Coarse
regression signal for A/B and capture runs on device; the rigorous gate
remains perf stat instructions+cycles with pinned clocks.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

pcsx2/PerformanceMetrics.cpp

@@ -4,6 +4,7 @@
 #include <chrono>
 #include <vector>
 
+#include "common/Console.h"
 #include "common/Timer.h"
 #include "common/Threading.h"
 
@@ -30,6 +31,15 @@ static u32 s_unskipped_frames_since_last_update = 0;
 static Common::Timer s_last_update_time;
 static Common::Timer s_last_frame_time;
 
+// Session perf logging: a rolling emulog line every ~30s of presented
+// frames, and a whole-session average at shutdown (LogSessionSummary).
+// Gives every -logfile run a durable framerate record. Wall-clock based:
+// paused time dilutes the session average but not the rolling lines.
+static const float LOG_INTERVAL = 30.0f;
+static Common::Timer s_session_timer;
+static float s_log_accum_time = 0.0f;
+static u32 s_log_accum_frames = 0;
+
 // frame number, updated by the GS thread
 static u64 s_frame_number = 0;
 
@@ -96,10 +106,24 @@ void PerformanceMetrics::Clear()
 
 	s_frame_number = 0;
 
+	s_session_timer.Reset();
+	s_log_accum_time = 0.0f;
+	s_log_accum_frames = 0;
+
 	s_frame_time_history.fill(0.0f);
 	s_frame_time_history_pos = 0;
 }
 
+void PerformanceMetrics::LogSessionSummary()
+{
+	const double elapsed = s_session_timer.GetTimeSeconds();
+	if (s_frame_number == 0 || elapsed < 1.0)
+		return;
+	Console.WriteLn("PerfLog session: %llu frames in %.1fs wall = %.2f fps average",
+		static_cast<unsigned long long>(s_frame_number), elapsed,
+		static_cast<double>(s_frame_number) / elapsed);
+}
+
 void PerformanceMetrics::Reset()
 {
 	s_frames_since_last_update = 0;
@@ -221,6 +245,19 @@ void PerformanceMetrics::Update(bool gs_register_write, bool fb_blit, bool is_sk
 		thread.time = static_cast<double>(delta) * time_divider;
 	}
 
+	// Rolling perf log (uses this window's frame count before it resets).
+	s_log_accum_time += time;
+	s_log_accum_frames += s_frames_since_last_update;
+	if (s_log_accum_time >= LOG_INTERVAL)
+	{
+		Console.WriteLn("PerfLog: %.1f fps | EE %.0f%% GS %.0f%% VU %.0f%% GPU %.0f%% | frame %llu",
+			static_cast<float>(s_log_accum_frames) / s_log_accum_time, s_cpu_thread_usage,
+			s_gs_thread_usage, s_vu_thread_usage, s_gpu_usage,
+			static_cast<unsigned long long>(s_frame_number));
+		s_log_accum_time = 0.0f;
+		s_log_accum_frames = 0;
+	}
+
 	s_frames_since_last_update = 0;
 	s_unskipped_frames_since_last_update = 0;
 	s_presents_since_last_update = 0;

pcsx2/PerformanceMetrics.h

@@ -23,6 +23,10 @@ namespace PerformanceMetrics
 	void Update(bool gs_register_write, bool fb_blit, bool is_skipping_present);
 	void OnGPUPresent(float gpu_time);
 
+	/// Logs the whole-session average framerate (frames since Clear() over
+	/// wall time). Called at VM shutdown so every -logfile run records it.
+	void LogSessionSummary();
+
 	/// Sets the EE thread for CPU usage calculations.
 	void SetCPUThread(Threading::ThreadHandle thread);
 

pcsx2/VMManager.cpp

@@ -1663,6 +1663,8 @@ void VMManager::Shutdown(bool save_resume_state)
 	// but just in case, so any of the stuff we call here knows we don't have a valid VM.
 	s_state.store(VMState::Stopping, std::memory_order_release);
 
+	PerformanceMetrics::LogSessionSummary();
+
 	SetTimerResolutionIncreased(false);
 
 	// sync everything