sched: Introduce task_is_running()

Replace a bunch of 'p->state == TASK_RUNNING' with a new helper:
task_is_running(p).

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210611082838.222401495@infradead.org

kernel/kcsan/report.c

@@ -460,7 +460,7 @@ static void set_other_info_task_blocking(unsigned long *flags,
 	 * We may be instrumenting a code-path where current->state is already
 	 * something other than TASK_RUNNING.
 	 */
-	const bool is_running = current->state == TASK_RUNNING;
+	const bool is_running = task_is_running(current);
 	/*
 	 * To avoid deadlock in case we are in an interrupt here and this is a
 	 * race with a task on the same CPU (KCSAN_INTERRUPT_WATCHER), provide a

kernel/locking/lockdep.c

@@ -760,7 +760,7 @@ static void lockdep_print_held_locks(struct task_struct *p)
 	 * It's not reliable to print a task's held locks if it's not sleeping
 	 * and it's not the current task.
 	 */
-	if (p->state == TASK_RUNNING && p != current)
+	if (p != current && task_is_running(p))
 		return;
 	for (i = 0; i < depth; i++) {
 		printk(" #%d: ", i);

kernel/rcu/tree_plugin.h

@@ -2768,7 +2768,7 @@ EXPORT_SYMBOL_GPL(rcu_bind_current_to_nocb);
 #ifdef CONFIG_SMP
 static char *show_rcu_should_be_on_cpu(struct task_struct *tsp)
 {
-	return tsp && tsp->state == TASK_RUNNING && !tsp->on_cpu ? "!" : "";
+	return tsp && task_is_running(tsp) && !tsp->on_cpu ? "!" : "";
 }
 #else // #ifdef CONFIG_SMP
 static char *show_rcu_should_be_on_cpu(struct task_struct *tsp)

kernel/sched/core.c

@@ -5974,7 +5974,7 @@ static inline void sched_submit_work(struct task_struct *tsk)
 {
 	unsigned int task_flags;
 
-	if (!tsk->state)
+	if (task_is_running(tsk))
 		return;
 
 	task_flags = tsk->flags;
@@ -7949,7 +7949,7 @@ again:
 	if (curr->sched_class != p->sched_class)
 		goto out_unlock;
 
-	if (task_running(p_rq, p) || p->state)
+	if (task_running(p_rq, p) || !task_is_running(p))
 		goto out_unlock;
 
 	yielded = curr->sched_class->yield_to_task(rq, p);
@@ -8152,7 +8152,7 @@ void sched_show_task(struct task_struct *p)
 
 	pr_info("task:%-15.15s state:%c", p->comm, task_state_to_char(p));
 
-	if (p->state == TASK_RUNNING)
+	if (task_is_running(p))
 		pr_cont("  running task    ");
 #ifdef CONFIG_DEBUG_STACK_USAGE
 	free = stack_not_used(p);

kernel/sched/stats.h

@@ -217,7 +217,7 @@ static inline void sched_info_depart(struct rq *rq, struct task_struct *t)
 
 	rq_sched_info_depart(rq, delta);
 
-	if (t->state == TASK_RUNNING)
+	if (task_is_running(t))
 		sched_info_enqueue(rq, t);
 }
 

kernel/signal.c

@@ -4719,7 +4719,7 @@ void kdb_send_sig(struct task_struct *t, int sig)
 	}
 	new_t = kdb_prev_t != t;
 	kdb_prev_t = t;
-	if (t->state != TASK_RUNNING && new_t) {
+	if (!task_is_running(t) && new_t) {
 		spin_unlock(&t->sighand->siglock);
 		kdb_printf("Process is not RUNNING, sending a signal from "
 			   "kdb risks deadlock\n"

kernel/softirq.c

@@ -92,8 +92,7 @@ static bool ksoftirqd_running(unsigned long pending)
 
 	if (pending & SOFTIRQ_NOW_MASK)
 		return false;
-	return tsk && (tsk->state == TASK_RUNNING) &&
-		!__kthread_should_park(tsk);
+	return tsk && task_is_running(tsk) && !__kthread_should_park(tsk);
 }
 
 #ifdef CONFIG_TRACE_IRQFLAGS