saving working state of EDF + core scheduler in actual OS

init/main.c

@@ -251,7 +251,7 @@ int kernel_main(void)
 	attr.wcet         = us_to_ktime(200);
 	sched_set_attr(t, &attr);
 	kthread_wake_up(t);
-
+#if 1
 	t = kthread_create(task3, NULL, KTHREAD_CPU_AFFINITY_NONE, "print2");
 	sched_get_attr(t, &attr);
 	attr.policy = SCHED_EDF;
@@ -260,7 +260,8 @@ int kernel_main(void)
 	attr.wcet         = us_to_ktime(100);
 	sched_set_attr(t, &attr);
 	kthread_wake_up(t);
-
+#endif
+#if 1
 	t = kthread_create(task1, NULL, KTHREAD_CPU_AFFINITY_NONE, "print3");
 	sched_get_attr(t, &attr);
 	attr.policy = SCHED_EDF;
@@ -269,7 +270,8 @@ int kernel_main(void)
 	attr.wcet         = us_to_ktime(100);
 	sched_set_attr(t, &attr);
 	kthread_wake_up(t);
-
+#endif
+#if 1
 	t = kthread_create(task0, NULL, KTHREAD_CPU_AFFINITY_NONE, "res");
 	sched_get_attr(t, &attr);
 	attr.policy = SCHED_EDF;
@@ -278,7 +280,7 @@ int kernel_main(void)
 	attr.wcet         = ms_to_ktime(100);
 	sched_set_attr(t, &attr);
 	kthread_wake_up(t);
-
+#endif
 
 #endif
 

kernel/sched/core.c

@@ -36,7 +36,9 @@ void schedule(void)
 
 	struct task_struct *current;
 	int64_t slot_ns;
-	int64_t wake_ns = 0;
+	int64_t wake_ns = 1000000000;
+
+	ktime rt;
 
 
 	static int once;
@@ -55,12 +57,20 @@ void schedule(void)
 	/* get the current task for this CPU */
 	current = current_set[0]->task;
 
+
+	rt = ktime_sub(ktime_get(), current->exec_start);
+
 	/** XXX need timeslice_update callback for schedulers */
 	/* update remaining runtime of current thread */
-	current->runtime = ktime_sub(current->exec_start, ktime_get());
+
+	current->runtime = ktime_sub(current->runtime, rt);
+	current->total = ktime_add(current->total, rt);
+
 
 
 retry:
+	next = NULL;
+	wake_ns = 1000000000;
 	/* XXX: for now, try to wake up any threads not running
 	 * this is a waste of cycles and instruction space; should be
 	 * done in the scheduler's code (somewhere) */
@@ -82,13 +92,15 @@ retry:
 		 * next is non-NULL
 		 */
 		next = sched->pick_next_task(&sched->tq);
+
 #if 0
 		if (next)
 			printk("next %s %llu %llu\n", next->name, next->first_wake, ktime_get());
 		else
-			printk("NULL\n");
+			printk("NULL %llu\n", ktime_get());
 #endif
 
+
 		/* check if we need to limit the next tasks timeslice;
 		 * since our scheduler list is sorted by scheduler priority,
 		 * only update the value if wake_next is not set;
@@ -109,22 +121,17 @@ retry:
 		 * the corresponding scheduler
 		 */
 
-		if (!wake_ns)
-			wake_ns = sched->task_ready_ns(&sched->tq);
-
-		/* we found something to execute, off we go */
-		if (next)
+		if (next) {
+			slot_ns = next->sched->timeslice_ns(next);
+			/* we found something to execute, off we go */
 			break;
+		}
 	}
 
 
 	if (!next) {
 		/* there is absolutely nothing nothing to do, check again later */
-		if (wake_ns)
-			tick_set_next_ns(wake_ns);
-		else
-			tick_set_next_ns(1e9);	/* XXX pause for a second, there are no threads in any scheduler */
-
+		tick_set_next_ns(wake_ns);
 		goto exit;
 	}
 
@@ -134,7 +141,7 @@ retry:
 	 * schedulers, e.g. EDF
 	 */
 
-	slot_ns = next->sched->timeslice_ns(next);
+	wake_ns = sched->task_ready_ns(&sched->tq);
 
 	if (wake_ns < slot_ns)
 		slot_ns  = wake_ns;
@@ -152,9 +159,9 @@ retry:
 	/* subtract readout overhead */
 	tick_set_next_ns(ktime_sub(slot_ns, 2000LL));
 #if 1
-	if (slot_ns < 20000UL) {
+	if (slot_ns < 19000UL) {
+	//	printk("wake %llu slot %llu %s\n", wake_ns, slot_ns, next->name);
 		goto retry;
-		printk("wake %llu slot %llu %s\n", wake_ns, slot_ns, next->name);
 		BUG();
 	}
 #endif

kernel/sched/edf.c

@@ -107,6 +107,7 @@ static inline bool schedule_edf_can_execute(struct task_struct *tsk, ktime now)
 	if (tsk->runtime <= 0)
 		return false;
 	if (ktime_before(tsk->deadline, now))  {
+		sched_print_edf_list_internal(&tsk->sched->tq, ktime_get());
 		printk("%s violated, %lld %lld, dead %lld wake %lld now %lld start %lld\n", tsk->name,
 		       tsk->runtime, ktime_us_delta(tsk->deadline, now),
 		       tsk->deadline, tsk->wakeup, now, tsk->exec_start);
@@ -153,6 +154,8 @@ static inline void schedule_edf_reinit_task(struct task_struct *tsk, ktime now)
 	tsk->deadline = ktime_add(tsk->wakeup, tsk->attr.deadline_rel);
 
 	tsk->runtime = tsk->attr.wcet;
+
+	tsk->slices++;
 }
 
 
@@ -242,7 +245,6 @@ static int edf_schedulable(struct task_queue *tq, const struct task_struct *task
 		return 0;
 	}
 
-	u = (double) (int32_t) task->attr.wcet / (double) (int32_t) task->attr.period;
 
 	return 0;
 }
@@ -346,7 +348,7 @@ static struct task_struct *edf_pick_next(struct task_queue *tq)
 		slot = first->runtime;
        }
 
-#if 0 /* XXX should not be needed, but needs verification! */
+#if 1 /* XXX should not be needed, but needs verification! */
        if (!go) {
 	       list_for_each_entry_safe(tsk, tmp, &tq->run, node) {