Merge tag 'sched_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Borislav Petkov:
 "Mostly minor things this time; some highlights:

   - core-sched: Add 'Forced Idle' accounting; this allows to track how
     much CPU time is 'lost' due to core scheduling constraints.

   - psi: Fix for MEM_FULL; a task running reclaim would be counted as a
     runnable task and prevent MEM_FULL from being reported.

   - cpuacct: Long standing fixes for some cgroup accounting issues.

   - rt: Bandwidth timer could, under unusual circumstances, be failed
     to armed, leading to indefinite throttling."

[ Description above by Peter Zijlstra ]

* tag 'sched_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Replace CFS internal cpu_util() with cpu_util_cfs()
  sched/fair: Cleanup task_util and capacity type
  sched/rt: Try to restart rt period timer when rt runtime exceeded
  sched/fair: Document the slow path and fast path in select_task_rq_fair
  sched/fair: Fix per-CPU kthread and wakee stacking for asym CPU capacity
  sched/fair: Fix detection of per-CPU kthreads waking a task
  sched/cpuacct: Make user/system times in cpuacct.stat more precise
  sched/cpuacct: Fix user/system in shown cpuacct.usage*
  cpuacct: Convert BUG_ON() to WARN_ON_ONCE()
  cputime, cpuacct: Include guest time in user time in cpuacct.stat
  psi: Fix PSI_MEM_FULL state when tasks are in memstall and doing reclaim
  sched/core: Forced idle accounting
  psi: Add a missing SPDX license header
  psi: Remove repeated verbose comment

1 files changed, 18 insertions, 5 deletions

diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index b48baaba2fc2..7b4f4fbbb404 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -52,11 +52,8 @@ void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime)
 	rt_b->rt_period_timer.function = sched_rt_period_timer;
 }
 
-static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
+static inline void do_start_rt_bandwidth(struct rt_bandwidth *rt_b)
 {
-	if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)
-		return;
-
 	raw_spin_lock(&rt_b->rt_runtime_lock);
 	if (!rt_b->rt_period_active) {
 		rt_b->rt_period_active = 1;
@@ -75,6 +72,14 @@ static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
 	raw_spin_unlock(&rt_b->rt_runtime_lock);
 }
 
+static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
+{
+	if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)
+		return;
+
+	do_start_rt_bandwidth(rt_b);
+}
+
 void init_rt_rq(struct rt_rq *rt_rq)
 {
 	struct rt_prio_array *array;
@@ -1031,13 +1036,17 @@ static void update_curr_rt(struct rq *rq)
 
 	for_each_sched_rt_entity(rt_se) {
 		struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
+		int exceeded;
 
 		if (sched_rt_runtime(rt_rq) != RUNTIME_INF) {
 			raw_spin_lock(&rt_rq->rt_runtime_lock);
 			rt_rq->rt_time += delta_exec;
-			if (sched_rt_runtime_exceeded(rt_rq))
+			exceeded = sched_rt_runtime_exceeded(rt_rq);
+			if (exceeded)
 				resched_curr(rq);
 			raw_spin_unlock(&rt_rq->rt_runtime_lock);
+			if (exceeded)
+				do_start_rt_bandwidth(sched_rt_bandwidth(rt_rq));
 		}
 	}
 }
@@ -2911,8 +2920,12 @@ static int sched_rt_global_validate(void)
 
 static void sched_rt_do_global(void)
 {
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags);
 	def_rt_bandwidth.rt_runtime = global_rt_runtime();
 	def_rt_bandwidth.rt_period = ns_to_ktime(global_rt_period());
+	raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags);
 }
 
 int sched_rt_handler(struct ctl_table *table, int write, void *buffer,