Make scheduler_reschedule() an no-op until we're ready to start the

scheduler. This avoids the need to use the send_signal_etc() work-around for
resume_thread() during the early kernel initialization. Might fix #5851.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36530 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/kscheduler.h

@@ -62,6 +62,7 @@ void scheduler_add_listener(struct SchedulerListener* listener);
 void scheduler_remove_listener(struct SchedulerListener* listener);
 
 void scheduler_init(void);
+void scheduler_enable_scheduling(void);
 
 bigtime_t _user_estimate_max_scheduling_latency(thread_id thread);
 status_t _user_analyze_scheduling(bigtime_t from, bigtime_t until, void* buffer,

src/system/kernel/main.cpp

@@ -192,7 +192,10 @@ _start(kernel_args *bootKernelArgs, int currentCPU)
 		TRACE("spawning main2 thread\n");
 		thread_id thread = spawn_kernel_thread(&main2, "main2",
 			B_NORMAL_PRIORITY, NULL);
-		send_signal_etc(thread, SIGCONT, B_DO_NOT_RESCHEDULE);
+		resume_thread(thread);
+
+		// We're ready to start the scheduler and enable interrupts on all CPUs.
+		scheduler_enable_scheduling();
 
 		// bring up the AP cpus in a lock step fashion
 		TRACE("waking up AP cpus\n");

src/system/kernel/scheduler/scheduler.cpp

@@ -18,6 +18,17 @@
 struct scheduler_ops* gScheduler;
 SchedulerListenerList gSchedulerListeners;
 
+static void (*sRescheduleFunction)(void);
+
+
+static void
+scheduler_reschedule_no_op(void)
+{
+}
+
+
+// #pragma mark -
+
 
 SchedulerListener::~SchedulerListener()
 {
@@ -62,6 +73,11 @@ scheduler_init(void)
 		scheduler_simple_init();
 	}
 
+	// Disable rescheduling until the basic kernel initialization is done and
+	// CPUs are ready to enable interrupts.
+	sRescheduleFunction = gScheduler->reschedule;
+	gScheduler->reschedule = scheduler_reschedule_no_op;
+
 #if SCHEDULER_TRACING
 	add_debugger_command_etc("scheduler", &cmd_scheduler,
 		"Analyze scheduler tracing information",
@@ -72,6 +88,13 @@ scheduler_init(void)
 }
 
 
+void
+scheduler_enable_scheduling(void)
+{
+	gScheduler->reschedule = sRescheduleFunction;
+}
+
+
 // #pragma mark - Syscalls