1 files changed, 48 insertions, 54 deletions

diff --git a/kernel/sched/stop_task.c b/kernel/sched/stop_task.c
index e08fbeeb54b9..4f9192be4b5b 100644
--- a/kernel/sched/stop_task.c
+++ b/kernel/sched/stop_task.c
@@ -1,5 +1,4 @@
-#include "sched.h"
-
+// SPDX-License-Identifier: GPL-2.0
 /*
  * stop-task scheduling class.
  *
@@ -8,43 +7,50 @@
  *
  * See kernel/stop_machine.c
  */
+#include "sched.h"
 
-#ifdef CONFIG_SMP
 static int
-select_task_rq_stop(struct task_struct *p, int sd_flag, int flags)
+select_task_rq_stop(struct task_struct *p, int cpu, int flags)
 {
 	return task_cpu(p); /* stop tasks as never migrate */
 }
-#endif /* CONFIG_SMP */
+
+static int
+balance_stop(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
+{
+	return sched_stop_runnable(rq);
+}
 
 static void
-check_preempt_curr_stop(struct rq *rq, struct task_struct *p, int flags)
+wakeup_preempt_stop(struct rq *rq, struct task_struct *p, int flags)
 {
 	/* we're never preempted */
 }
 
-static struct task_struct *pick_next_task_stop(struct rq *rq)
+static void set_next_task_stop(struct rq *rq, struct task_struct *stop, bool first)
 {
-	struct task_struct *stop = rq->stop;
+	stop->se.exec_start = rq_clock_task(rq);
+}
 
-	if (stop && stop->on_rq) {
-		stop->se.exec_start = rq_clock_task(rq);
-		return stop;
-	}
+static struct task_struct *pick_task_stop(struct rq *rq, struct rq_flags *rf)
+{
+	if (!sched_stop_runnable(rq))
+		return NULL;
 
-	return NULL;
+	return rq->stop;
 }
 
 static void
 enqueue_task_stop(struct rq *rq, struct task_struct *p, int flags)
 {
-	inc_nr_running(rq);
+	add_nr_running(rq, 1);
 }
 
-static void
+static bool
 dequeue_task_stop(struct rq *rq, struct task_struct *p, int flags)
 {
-	dec_nr_running(rq);
+	sub_nr_running(rq, 1);
+	return true;
 }
 
 static void yield_task_stop(struct rq *rq)
@@ -52,77 +58,65 @@ static void yield_task_stop(struct rq *rq)
 	BUG(); /* the stop task should never yield, its pointless. */
 }
 
-static void put_prev_task_stop(struct rq *rq, struct task_struct *prev)
+static void put_prev_task_stop(struct rq *rq, struct task_struct *prev, struct task_struct *next)
 {
-	struct task_struct *curr = rq->curr;
-	u64 delta_exec;
-
-	delta_exec = rq_clock_task(rq) - curr->se.exec_start;
-	if (unlikely((s64)delta_exec < 0))
-		delta_exec = 0;
-
-	schedstat_set(curr->se.statistics.exec_max,
-			max(curr->se.statistics.exec_max, delta_exec));
-
-	curr->se.sum_exec_runtime += delta_exec;
-	account_group_exec_runtime(curr, delta_exec);
-
-	curr->se.exec_start = rq_clock_task(rq);
-	cpuacct_charge(curr, delta_exec);
+	update_curr_common(rq);
 }
 
+/*
+ * scheduler tick hitting a task of our scheduling class.
+ *
+ * NOTE: This function can be called remotely by the tick offload that
+ * goes along full dynticks. Therefore no local assumption can be made
+ * and everything must be accessed through the @rq and @curr passed in
+ * parameters.
+ */
 static void task_tick_stop(struct rq *rq, struct task_struct *curr, int queued)
 {
 }
 
-static void set_curr_task_stop(struct rq *rq)
-{
-	struct task_struct *stop = rq->stop;
-
-	stop->se.exec_start = rq_clock_task(rq);
-}
-
-static void switched_to_stop(struct rq *rq, struct task_struct *p)
+static void switching_to_stop(struct rq *rq, struct task_struct *p)
 {
 	BUG(); /* its impossible to change to this class */
 }
 
 static void
-prio_changed_stop(struct rq *rq, struct task_struct *p, int oldprio)
+prio_changed_stop(struct rq *rq, struct task_struct *p, u64 oldprio)
 {
+	if (p->prio == oldprio)
+		return;
+
 	BUG(); /* how!?, what priority? */
 }
 
-static unsigned int
-get_rr_interval_stop(struct rq *rq, struct task_struct *task)
+static void update_curr_stop(struct rq *rq)
 {
-	return 0;
 }
 
 /*
  * Simple, special scheduling class for the per-CPU stop tasks:
  */
-const struct sched_class stop_sched_class = {
-	.next			= &rt_sched_class,
+DEFINE_SCHED_CLASS(stop) = {
+
+	.queue_mask		= 16,
 
 	.enqueue_task		= enqueue_task_stop,
 	.dequeue_task		= dequeue_task_stop,
 	.yield_task		= yield_task_stop,
 
-	.check_preempt_curr	= check_preempt_curr_stop,
+	.wakeup_preempt		= wakeup_preempt_stop,
 
-	.pick_next_task		= pick_next_task_stop,
+	.pick_task		= pick_task_stop,
 	.put_prev_task		= put_prev_task_stop,
+	.set_next_task          = set_next_task_stop,
 
-#ifdef CONFIG_SMP
+	.balance		= balance_stop,
 	.select_task_rq		= select_task_rq_stop,
-#endif
+	.set_cpus_allowed	= set_cpus_allowed_common,
 
-	.set_curr_task          = set_curr_task_stop,
 	.task_tick		= task_tick_stop,
 
-	.get_rr_interval	= get_rr_interval_stop,
-
 	.prio_changed		= prio_changed_stop,
-	.switched_to		= switched_to_stop,
+	.switching_to		= switching_to_stop,
+	.update_curr		= update_curr_stop,
 };