Kernel: Fix scheduler load balancing

I was not updating the current queue of the thread which lead to blocked
threads think they were in run queue

kernel/kernel/Scheduler.cpp

@@ -7,7 +7,6 @@
 #include <kernel/Timer/Timer.h>
 
 #define SCHEDULER_ASSERT 1
-#define SCHEDULER_LOAD_BALANCE 0
 
 #if SCHEDULER_ASSERT == 0
 #undef ASSERT
@@ -296,9 +295,8 @@ namespace Kernel
 	{
 		ASSERT(Processor::get_interrupt_state() == InterruptState::Disabled);
 
-		if constexpr(SCHEDULER_LOAD_BALANCE)
-			if (Processor::is_smp_enabled())
-				do_load_balancing();
+		if (Processor::is_smp_enabled())
+			do_load_balancing();
 
 		{
 			const uint64_t current_ns = SystemTimer::get().ns_since_boot();
@@ -339,6 +337,7 @@ namespace Kernel
 			node->blocked = false;
 			if (node != m_current)
 				m_run_queue.add_thread_to_back(node);
+			update_most_loaded_node_queue(node, &m_run_queue);
 		}
 		else
 		{
@@ -388,7 +387,6 @@ namespace Kernel
 		return least_loaded_id;
 	}
 
-#if SCHEDULER_LOAD_BALANCE
 	void Scheduler::do_load_balancing()
 	{
 		ASSERT(Processor::get_interrupt_state() == InterruptState::Disabled);
@@ -421,9 +419,9 @@ namespace Kernel
 
 			if (m_current)
 			{
-				const char* name = "unknown";
-				if (m_current->thread->has_process() && m_current->thread->process().is_userspace() && m_current->thread->process().userspace_info().argv)
-					name = m_current->thread->process().userspace_info().argv[0];
+				const char* name = "<unknown>";
+				if (m_current->thread->has_process() && *m_current->thread->process().name())
+					name = m_current->thread->process().name();
 				const uint64_t load_percent_x1000 = BAN::Math::div_round_up<uint64_t>(m_current->time_used_ns * 100'000, processing_ns);
 				dprintln("  tid { 2}: { 3}.{3}% <{}> current", m_current->thread->tid(), load_percent_x1000 / 1000, load_percent_x1000 % 1000, name);
 			}
@@ -474,9 +472,6 @@ namespace Kernel
 				break;
 			if (thread_info.node == m_current || thread_info.queue == nullptr)
 				continue;
-			// FIXME: allow load balancing with blocked threads, with this algorithm there is a race condition
-			if (thread_info.node->blocked)
-				continue;
 
 			auto least_loaded_id = find_least_loaded_processor();
 			if (least_loaded_id == Processor::current_id())
@@ -566,7 +561,6 @@ namespace Kernel
 
 		m_last_load_balance_ns += s_load_balance_interval_ns;
 	}
-#endif
 
 	BAN::ErrorOr<void> Scheduler::bind_thread_to_processor(Thread* thread, ProcessorID processor_id)
 	{
@@ -610,12 +604,14 @@ namespace Kernel
 		auto state = Processor::get_interrupt_state();
 		Processor::set_interrupt_state(InterruptState::Disabled);
 
+		ASSERT(m_current->processor_id == Processor::current_id());
 		ASSERT(!m_current->blocked);
 
 		m_current->blocked = true;
 		m_current->wake_time_ns = wake_time_ns;
 		if (blocker)
 			blocker->add_thread_to_block_queue(m_current);
+		update_most_loaded_node_queue(m_current, &m_block_queue);
 		Processor::yield();
 
 		Processor::set_interrupt_state(state);

kernel/kernel/Terminal/TTY.cpp

@@ -302,6 +302,8 @@ namespace Kernel
 				ASSERT(m_output.bytes > 0);
 				m_output.bytes--;
 				putchar('\b');
+				putchar(' ');
+				putchar('\b');
 			}
 			// Caret notation
 			else if (last < 32 || last == 127)
@@ -309,12 +311,18 @@ namespace Kernel
 				m_output.bytes--;
 				putchar('\b');
 				putchar('\b');
+				putchar(' ');
+				putchar(' ');
+				putchar('\b');
+				putchar('\b');
 			}
 			// Ascii
 			else
 			{
 				m_output.bytes--;
 				putchar('\b');
+				putchar(' ');
+				putchar('\b');
 			}
 		}
 	}

kernel/kernel/Terminal/VirtualTTY.cpp

@@ -306,8 +306,7 @@ namespace Kernel
 				dprintln_if(DEBUG_VTTY, "Unsupported ANSI CSI character f");
 				return;
 			case 'm':
-				handle_ansi_csi_color(BAN::Math::max(m_ansi_state.nums[0], 0));
-				for (int i = 1; i < m_ansi_state.index; i++)
+				for (int i = 0; i <= m_ansi_state.index && i < static_cast<int>(max_ansi_args); i++)
 					handle_ansi_csi_color(BAN::Math::max(m_ansi_state.nums[i], 0));
 				return reset_ansi();
 			case 's':
@@ -361,11 +360,24 @@ namespace Kernel
 					return reset_ansi();
 				}
 				reset_ansi();
-				dprintln_if(DEBUG_VTTY, "invalid ANSI CSI ?{}{}", m_ansi_state.nums[0], (char)ch);
+				dprintln_if(DEBUG_VTTY, "invalid ANSI CSI character {}", static_cast<char>(ch));
+				return;
+			case 'n':
+				if (m_ansi_state.nums[0] == 6)
+				{
+					char buffer[2 + 10 + 1 + 10 + 1];
+					size_t len = 0;
+					BAN::Formatter::print([&](char ch) { buffer[len++] = ch; }, "\e[{};{}R", m_row + 1, m_column + 1);
+					for (size_t i = 0; i < len; i++)
+						handle_input_byte(buffer[i]);
+					return reset_ansi();
+				};
+				reset_ansi();
+				dprintln_if(DEBUG_VTTY, "Unsupported ANSI CSI character n");
 				return;
 			default:
 				reset_ansi();
-				dprintln_if(DEBUG_VTTY, "Unsupported ANSI CSI character {}", ch);
+				dprintln_if(DEBUG_VTTY, "Unsupported ANSI CSI character {}", static_cast<char>(ch));
 				return;
 		}
 	}
@@ -399,7 +411,7 @@ namespace Kernel
 				break;
 			case BS:
 				if (m_column > 0)
-					putchar_at(' ', --m_column, m_row);
+					m_column--;
 				break;
 			case HT:
 				m_column++;

userspace/programs/Terminal/Terminal.cpp

@@ -276,9 +276,9 @@ bool Terminal::read_shell()
 	return true;
 }
 
-void Terminal::handle_sgr()
+void Terminal::handle_sgr(int32_t value)
 {
-	switch (m_csi_info.fields[0])
+	switch (value)
 	{
 		case -1: case 0:
 			m_bg_color = s_default_bg_color;
@@ -298,25 +298,25 @@ void Terminal::handle_sgr()
 			m_colors_inverted = false;
 			break;
 		case 30: case 31: case 32: case 33: case 34: case 35: case 36: case 37:
-			m_fg_color = s_colors_dark[m_csi_info.fields[0] - 30];
+			m_fg_color = s_colors_dark[value - 30];
 			break;
 		case 39:
 			m_fg_color = s_default_fg_color;
 			break;
 		case 40: case 41: case 42: case 43: case 44: case 45: case 46: case 47:
-			m_bg_color = s_colors_dark[m_csi_info.fields[0] - 40];
+			m_bg_color = s_colors_dark[value - 40];
 			break;
 		case 49:
 			m_bg_color = s_default_bg_color;
 			break;
 		case 90: case 91: case 92: case 93: case 94: case 95: case 96: case 97:
-			m_fg_color = s_colors_bright[m_csi_info.fields[0] - 90];
+			m_fg_color = s_colors_bright[value - 90];
 			break;
 		case 100: case 101: case 102: case 103: case 104: case 105: case 106: case 107:
-			m_bg_color = s_colors_bright[m_csi_info.fields[0] - 100];
+			m_bg_color = s_colors_bright[value - 100];
 			break;
 		default:
-			dprintln("TODO: SGR {}", m_csi_info.fields[0]);
+			dprintln("TODO: SGR {}", value);
 			break;
 	}
 }
@@ -337,7 +337,7 @@ Rectangle Terminal::handle_csi(char ch)
 
 	if (isdigit(ch))
 	{
-		if (m_csi_info.index <= 1)
+		if (m_csi_info.index < m_csi_info.max_fields)
 		{
 			auto& field = m_csi_info.fields[m_csi_info.index];
 			field = (BAN::Math::max(field, 0) * 10) + (ch - '0');
@@ -504,7 +504,8 @@ Rectangle Terminal::handle_csi(char ch)
 			m_cursor.y = BAN::Math::clamp<int32_t>(m_csi_info.fields[0], 1, rows()) - 1;
 			break;
 		case 'm':
-			handle_sgr();
+			for (size_t i = 0; i <= m_csi_info.index && i < m_csi_info.max_fields; i++)
+				handle_sgr(m_csi_info.fields[i]);
 			break;
 		case 's':
 			m_saved_cursor = m_cursor;
@@ -516,11 +517,21 @@ Rectangle Terminal::handle_csi(char ch)
 		case 'l':
 			if (!m_csi_info.question || m_csi_info.fields[0] != 25)
 			{
-				dprintln("invalid ANSI CSI ?{}{}", m_csi_info.fields[0], (char)ch);
+				dprintln("unsupported ANSI CSI {}", ch);
 				break;
 			}
 			m_cursor_shown = (ch == 'h');
 			break;
+		case 'n':
+			if (m_csi_info.fields[0] != 6)
+			{
+				dprintln("unsupported ANSI CSI n");
+				break;
+			}
+			char buffer[2 + 10 + 1 + 10 + 2];
+			sprintf(buffer, "\e[%u;%uR", m_cursor.y + 1, m_cursor.x + 1);
+			write(m_shell_info.pts_master, buffer, strlen(buffer));
+			break;
 		default:
 			dprintln("TODO: CSI {}", ch);
 			break;

userspace/programs/Terminal/Terminal.h

@@ -35,7 +35,7 @@ public:
 	uint32_t rows() const { return m_window->height() / m_font.height(); }
 
 private:
-	void handle_sgr();
+	void handle_sgr(int32_t value);
 	Rectangle handle_csi(char ch);
 	Rectangle putcodepoint(uint32_t codepoint);
 	Rectangle putchar(uint8_t ch);
@@ -70,7 +70,8 @@ private:
 
 	struct CSIInfo
 	{
-		int32_t fields[2];
+		static constexpr size_t max_fields = 2;
+		int32_t fields[max_fields];
 		size_t index;
 		bool question;
 	};