Remove reader_lock executed in every instruction by RSX

Use optimistic double check instead, use one load instruction for the check to be atomic

+ Read emu status once every FIFO iteration

rpcs3/Emu/RSX/RSXThread.cpp

@@ -527,7 +527,7 @@ namespace rsx
 		fesetround(FE_TONEAREST);
 
 		// TODO: exit condition
-		while (!Emu.IsStopped())
+		while (true)
 		{
 			// Wait for external pause events
 			if (external_interrupt_lock.load())
@@ -536,13 +536,6 @@ namespace rsx
 				while (external_interrupt_lock.load()) _mm_pause();
 			}
 
-			// Idle if emulation paused
-			if (Emu.IsPaused())
-			{
-				std::this_thread::sleep_for(1ms);
-				continue;
-			}
-
 			// Note a possible rollback address
 			if (sync_point_request)
 			{
@@ -559,6 +552,20 @@ namespace rsx
 
 			// Execute FIFO queue
 			run_FIFO();
+
+			if (!Emu.IsRunning())
+			{
+				// Idle if emulation paused
+				while (Emu.IsPaused())
+				{
+					std::this_thread::sleep_for(1ms);
+				}
+
+				if (Emu.IsStopped())
+				{
+					break;
+				}
+			}
 		}
 	}
 
@@ -900,12 +907,14 @@ namespace rsx
 
 		if (!in_begin_end && state != FIFO_state::lock_wait)
 		{
-			reader_lock lock(m_mtx_task);
-
-			if (m_invalidated_memory_range.valid())
+			if (atomic_storage<u32>::load(m_invalidated_memory_range.end) != 0)
 			{
-				lock.upgrade();
-				handle_invalidated_memory_range();
+				std::lock_guard lock(m_mtx_task);
+
+				if (m_invalidated_memory_range.valid())
+				{
+					handle_invalidated_memory_range();
+				}
 			}
 		}
 	}