Revert "ANDROID: sched/rt: schedtune: Add boost retention to RT"

This reverts commit d194ba5.

Reason for revert: Broke some builds. Will fix and resubmit.

Change-Id: I4e6fa1562346eda1bbf058f1d5ace5ba6256ce07

Author: toddkjos

include/linux/sched.h

@@ -1433,10 +1433,6 @@ struct sched_rt_entity {
 	unsigned long watchdog_stamp;
 	unsigned int time_slice;
 
-	/* Accesses for these must be guarded by rq->lock of the task's rq */
-	bool schedtune_enqueued;
-	struct hrtimer schedtune_timer;
-
 	struct sched_rt_entity *back;
 #ifdef CONFIG_RT_GROUP_SCHED
 	struct sched_rt_entity	*parent;

kernel/sched/core.c

@@ -2200,7 +2200,6 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p)
 	init_dl_task_timer(&p->dl);
 	__dl_clear_params(p);
 
-	init_rt_schedtune_timer(&p->rt);
 	INIT_LIST_HEAD(&p->rt.run_list);
 
 #ifdef CONFIG_PREEMPT_NOTIFIERS

kernel/sched/rt.c

@@ -7,7 +7,6 @@
 
 #include <linux/slab.h>
 #include <linux/irq_work.h>
-#include <linux/hrtimer.h>
 
 #include "walt.h"
 #include "tune.h"
@@ -987,73 +986,6 @@ static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq)
 	return 0;
 }
 
-#define RT_SCHEDTUNE_INTERVAL 50000000ULL
-
-static void sched_rt_update_capacity_req(struct rq *rq);
-
-static enum hrtimer_restart rt_schedtune_timer(struct hrtimer *timer)
-{
-	struct sched_rt_entity *rt_se = container_of(timer,
-			struct sched_rt_entity,
-			schedtune_timer);
-	struct task_struct *p = rt_task_of(rt_se);
-	struct rq *rq = task_rq(p);
-
-	raw_spin_lock(&rq->lock);
-
-	/*
-	 * Nothing to do if:
-	 * - task has switched runqueues
-	 * - task isn't RT anymore
-	 */
-	if (rq != task_rq(p) || (p->sched_class != &rt_sched_class))
-		goto out;
-
-	/*
-	 * If task got enqueued back during callback time, it means we raced
-	 * with the enqueue on another cpu, that's Ok, just do nothing as
-	 * enqueue path would have tried to cancel us and we shouldn't run
-	 * Also check the schedtune_enqueued flag as class-switch on a
-	 * sleeping task may have already canceled the timer and done dq
-	 */
-	if (p->on_rq || !rt_se->schedtune_enqueued)
-		goto out;
-
-	/*
-	 * RT task is no longer active, cancel boost
-	 */
-	rt_se->schedtune_enqueued = false;
-	schedtune_dequeue_task(p, cpu_of(rq));
-	sched_rt_update_capacity_req(rq);
-	cpufreq_update_this_cpu(rq, SCHED_CPUFREQ_RT);
-out:
-	raw_spin_unlock(&rq->lock);
-
-	/*
-	 * This can free the task_struct if no more references.
-	 */
-	put_task_struct(p);
-
-	return HRTIMER_NORESTART;
-}
-
-void init_rt_schedtune_timer(struct sched_rt_entity *rt_se)
-{
-	struct hrtimer *timer = &rt_se->schedtune_timer;
-
-	hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
-	timer->function = rt_schedtune_timer;
-	rt_se->schedtune_enqueued = false;
-}
-
-static void start_schedtune_timer(struct sched_rt_entity *rt_se)
-{
-	struct hrtimer *timer = &rt_se->schedtune_timer;
-
-	hrtimer_start(timer, ns_to_ktime(RT_SCHEDTUNE_INTERVAL),
-			HRTIMER_MODE_REL_PINNED);
-}
-
 /*
  * Update the current task's runtime statistics. Skip current tasks that
  * are not in our scheduling class.
@@ -1391,33 +1323,7 @@ enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags)
 	if (!task_current(rq, p) && p->nr_cpus_allowed > 1)
 		enqueue_pushable_task(rq, p);
 
-	if (!schedtune_task_boost(p))
-		return;
-
-	/*
-	 * If schedtune timer is active, that means a boost was already
-	 * done, just cancel the timer so that deboost doesn't happen.
-	 * Otherwise, increase the boost. If an enqueued timer was
-	 * cancelled, put the task reference.
-	 */
-	if (hrtimer_try_to_cancel(&rt_se->schedtune_timer) == 1)
-		put_task_struct(p);
-
-	/*
-	 * schedtune_enqueued can be true in the following situation:
-	 * enqueue_task_rt grabs rq lock before timer fires
-	 *    or before its callback acquires rq lock
-	 * schedtune_enqueued can be false if timer callback is running
-	 * and timer just released rq lock, or if the timer finished
-	 * running and canceling the boost
-	 */
-	if (rt_se->schedtune_enqueued)
-		return;
-
-	rt_se->schedtune_enqueued = true;
 	schedtune_enqueue_task(p, cpu_of(rq));
-	sched_rt_update_capacity_req(rq);
-	cpufreq_update_this_cpu(rq, SCHED_CPUFREQ_RT);
 }
 
 static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags)
@@ -1429,20 +1335,7 @@ static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags)
 	walt_dec_cumulative_runnable_avg(rq, p);
 
 	dequeue_pushable_task(rq, p);
-
-	if (!rt_se->schedtune_enqueued)
-		return;
-
-	if (flags == DEQUEUE_SLEEP) {
-		get_task_struct(p);
-		start_schedtune_timer(rt_se);
-		return;
-	}
-
-	rt_se->schedtune_enqueued = false;
 	schedtune_dequeue_task(p, cpu_of(rq));
-	sched_rt_update_capacity_req(rq);
-	cpufreq_update_this_cpu(rq, SCHED_CPUFREQ_RT);
 }
 
 /*
@@ -1482,33 +1375,6 @@ static void yield_task_rt(struct rq *rq)
 #ifdef CONFIG_SMP
 static int find_lowest_rq(struct task_struct *task);
 
-/*
- * Perform a schedtune dequeue and cancelation of boost timers if needed.
- * Should be called only with the rq->lock held.
- */
-static void schedtune_dequeue_rt(struct rq *rq, struct task_struct *p)
-{
-	struct sched_rt_entity *rt_se = &p->rt;
-
-	BUG_ON(!raw_spin_is_locked(&rq->lock));
-
-	if (!rt_se->schedtune_enqueued)
-		return;
-
-	/*
-	 * Incase of class change cancel any active timers. If an enqueued
-	 * timer was cancelled, put the task ref.
-	 */
-	if (hrtimer_try_to_cancel(&rt_se->schedtune_timer) == 1)
-		put_task_struct(p);
-
-	/* schedtune_enqueued is true, deboost it */
-	rt_se->schedtune_enqueued = false;
-	schedtune_dequeue_task(p, task_cpu(p));
-	sched_rt_update_capacity_req(rq);
-	cpufreq_update_this_cpu(rq, SCHED_CPUFREQ_RT);
-}
-
 static int
 select_task_rq_rt(struct task_struct *p, int cpu, int sd_flag, int flags,
 		  int sibling_count_hint)
@@ -1563,19 +1429,6 @@ select_task_rq_rt(struct task_struct *p, int cpu, int sd_flag, int flags,
 	rcu_read_unlock();
 
 out:
-	/*
-	 * If previous CPU was different, make sure to cancel any active
-	 * schedtune timers and deboost.
-	 */
-	if (task_cpu(p) != cpu) {
-		unsigned long fl;
-		struct rq *prq = task_rq(p);
-
-		raw_spin_lock_irqsave(&prq->lock, fl);
-		schedtune_dequeue_rt(prq, p);
-		raw_spin_unlock_irqrestore(&prq->lock, fl);
-	}
-
 	return cpu;
 }
 
@@ -2308,13 +2161,6 @@ static void rq_offline_rt(struct rq *rq)
  */
 static void switched_from_rt(struct rq *rq, struct task_struct *p)
 {
-	/*
-	 * On class switch from rt, always cancel active schedtune timers,
-	 * this handles the cases where we switch class for a task that is
-	 * already rt-dequeued but has a running timer.
-	 */
-	schedtune_dequeue_rt(rq, p);
-
 	/*
 	 * If there are other RT tasks then we will reschedule
 	 * and the scheduling of the other RT tasks will handle

kernel/sched/sched.h

@@ -1398,7 +1398,6 @@ extern void resched_cpu(int cpu);
 
 extern struct rt_bandwidth def_rt_bandwidth;
 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);
-extern void init_rt_schedtune_timer(struct sched_rt_entity *rt_se);
 
 extern struct dl_bandwidth def_dl_bandwidth;
 extern void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime);