[PATCH 1/2] nohz: clean up select_nohz_load_balancer()

[PATCH 1/2] nohz: clean up select_nohz_load_balancer()

[Alex Shi]

There is no load_balancer to be selected now. It just set state of
nohz tick stopping.

So rename the function, pass the 'cpu' from parameter and then
remove the useless calling from tick_nohz_restart_sched_tick().

Signed-off-by: Alex Shi <alex.shi@intel.com>
---
 include/linux/sched.h    |    4 ++--
 kernel/sched/fair.c      |   19 +++++++------------
 kernel/time/tick-sched.c |    3 +--
 3 files changed, 10 insertions(+), 16 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index b8c8664..5cba49c 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -273,11 +273,11 @@ extern void init_idle_bootup_task(struct task_struct *idle);
 extern int runqueue_is_locked(int cpu);
 
 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
-extern void select_nohz_load_balancer(int stop_tick);
+extern void set_nohz_tick_stopped(int cpu);
 extern void set_cpu_sd_state_idle(void);
 extern int get_nohz_timer_target(void);
 #else
-static inline void select_nohz_load_balancer(int stop_tick) { }
+static inline void set_nohz_tick_stopped(int cpu) { }
 static inline void set_cpu_sd_state_idle(void) { }
 #endif
 
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index c219bf8..5bbc4bf 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4674,28 +4674,23 @@ void set_cpu_sd_state_idle(void)
 }
 
 /*
- * This routine will record that this cpu is going idle with tick stopped.
+ * This routine will record that the cpu is going idle with tick stopped.
  * This info will be used in performing idle load balancing in the future.
  */
-void select_nohz_load_balancer(int stop_tick)
+void set_nohz_tick_stopped(int cpu)
 {
-	int cpu = smp_processor_id();
-
 	/*
 	 * If this cpu is going down, then nothing needs to be done.
 	 */
 	if (!cpu_active(cpu))
 		return;
 
-	if (stop_tick) {
-		if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))
-			return;
+	if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))
+		return;
 
-		cpumask_set_cpu(cpu, nohz.idle_cpus_mask);
-		atomic_inc(&nohz.nr_cpus);
-		set_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu));
-	}
-	return;
+	cpumask_set_cpu(cpu, nohz.idle_cpus_mask);
+	atomic_inc(&nohz.nr_cpus);
+	set_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu));
 }
 
 static int __cpuinit sched_ilb_notifier(struct notifier_block *nfb,
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 024540f..eacde97 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -372,7 +372,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
 		 * the scheduler tick in nohz_restart_sched_tick.
 		 */
 		if (!ts->tick_stopped) {
-			select_nohz_load_balancer(1);
+			set_nohz_tick_stopped(cpu);
 			calc_load_enter_idle();
 
 			ts->last_tick = hrtimer_get_expires(&ts->sched_timer);
@@ -569,7 +569,6 @@ static void tick_nohz_restart(struct tick_sched *ts, ktime_t now)
 static void tick_nohz_restart_sched_tick(struct tick_sched *ts, ktime_t now)
 {
 	/* Update jiffies first */
-	select_nohz_load_balancer(0);
 	tick_do_update_jiffies64(now);
 	update_cpu_load_nohz();
 
-- 
1.7.5.4

[PATCH 2/2] sched: trigger_load_balance clean up

[Alex Shi]

Remove a redundant check for on_null_domain(cpu), and rerange the code
that make it more readable.

Signed-off-by: Alex Shi <alex.shi@intel.com>
---
 kernel/sched/fair.c |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 5bbc4bf..529092d 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4934,11 +4934,13 @@ static inline int on_null_domain(int cpu)
 void trigger_load_balance(struct rq *rq, int cpu)
 {
 	/* Don't need to rebalance while attached to NULL domain */
-	if (time_after_eq(jiffies, rq->next_balance) &&
-	    likely(!on_null_domain(cpu)))
+	if (unlikely(on_null_domain(cpu)))
+		return;
+
+	if (time_after_eq(jiffies, rq->next_balance))
 		raise_softirq(SCHED_SOFTIRQ);
 #ifdef CONFIG_NO_HZ
-	if (nohz_kick_needed(rq, cpu) && likely(!on_null_domain(cpu)))
+	if (nohz_kick_needed(rq, cpu))
 		nohz_balancer_kick(cpu);
 #endif
 }
-- 
1.7.5.4

Re: [PATCH 1/2] nohz: clean up select_nohz_load_balancer()

[Peter Zijlstra]

On Mon, 2012-09-10 at 15:10 +0800, Alex Shi wrote:
> There is no load_balancer to be selected now. It just set state of
> nohz tick stopping.
> 
> So rename the function, pass the 'cpu' from parameter and then
> remove the useless calling from tick_nohz_restart_sched_tick().

Please check who wrote the code you're patching and attempt to CC them
as well, in this case Venki and Suresh.

I think the patch is fine, although I think we could have picked a
better name, how about nohz_balance_enter_idle() ?

> Signed-off-by: Alex Shi <alex.shi@intel.com>
> ---
>  include/linux/sched.h    |    4 ++--
>  kernel/sched/fair.c      |   19 +++++++------------
>  kernel/time/tick-sched.c |    3 +--
>  3 files changed, 10 insertions(+), 16 deletions(-)
> 
> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index b8c8664..5cba49c 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -273,11 +273,11 @@ extern void init_idle_bootup_task(struct task_struct *idle);
>  extern int runqueue_is_locked(int cpu);
>  
>  #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
> -extern void select_nohz_load_balancer(int stop_tick);
> +extern void set_nohz_tick_stopped(int cpu);
>  extern void set_cpu_sd_state_idle(void);
>  extern int get_nohz_timer_target(void);
>  #else
> -static inline void select_nohz_load_balancer(int stop_tick) { }
> +static inline void set_nohz_tick_stopped(int cpu) { }
>  static inline void set_cpu_sd_state_idle(void) { }
>  #endif
>  
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index c219bf8..5bbc4bf 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -4674,28 +4674,23 @@ void set_cpu_sd_state_idle(void)
>  }
>  
>  /*
> - * This routine will record that this cpu is going idle with tick stopped.
> + * This routine will record that the cpu is going idle with tick stopped.
>   * This info will be used in performing idle load balancing in the future.
>   */
> -void select_nohz_load_balancer(int stop_tick)
> +void set_nohz_tick_stopped(int cpu)
>  {
> -	int cpu = smp_processor_id();
> -
>  	/*
>  	 * If this cpu is going down, then nothing needs to be done.
>  	 */
>  	if (!cpu_active(cpu))
>  		return;
>  
> -	if (stop_tick) {
> -		if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))
> -			return;
> +	if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))
> +		return;
>  
> -		cpumask_set_cpu(cpu, nohz.idle_cpus_mask);
> -		atomic_inc(&nohz.nr_cpus);
> -		set_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu));
> -	}
> -	return;
> +	cpumask_set_cpu(cpu, nohz.idle_cpus_mask);
> +	atomic_inc(&nohz.nr_cpus);
> +	set_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu));
>  }
>  
>  static int __cpuinit sched_ilb_notifier(struct notifier_block *nfb,
> diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
> index 024540f..eacde97 100644
> --- a/kernel/time/tick-sched.c
> +++ b/kernel/time/tick-sched.c
> @@ -372,7 +372,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
>  		 * the scheduler tick in nohz_restart_sched_tick.
>  		 */
>  		if (!ts->tick_stopped) {
> -			select_nohz_load_balancer(1);
> +			set_nohz_tick_stopped(cpu);
>  			calc_load_enter_idle();
>  
>  			ts->last_tick = hrtimer_get_expires(&ts->sched_timer);
> @@ -569,7 +569,6 @@ static void tick_nohz_restart(struct tick_sched *ts, ktime_t now)
>  static void tick_nohz_restart_sched_tick(struct tick_sched *ts, ktime_t now)
>  {
>  	/* Update jiffies first */
> -	select_nohz_load_balancer(0);
>  	tick_do_update_jiffies64(now);
>  	update_cpu_load_nohz();
>  

Re: [PATCH 1/2] nohz: clean up select_nohz_load_balancer()

[Alex Shi]

On 09/10/2012 11:26 PM, Peter Zijlstra wrote:

> On Mon, 2012-09-10 at 15:10 +0800, Alex Shi wrote:
>> There is no load_balancer to be selected now. It just set state of
>> nohz tick stopping.
>>
>> So rename the function, pass the 'cpu' from parameter and then
>> remove the useless calling from tick_nohz_restart_sched_tick().
> 
> Please check who wrote the code you're patching and attempt to CC them
> as well, in this case Venki and Suresh.


Thanks! will care about this from now on.

> 
> I think the patch is fine, although I think we could have picked a
> better name, how about nohz_balance_enter_idle() ?


nohz_balance_enter_idle is good a name too. but I name it as
set_nohz_tick_stopped, since there is a clear_nohz_tick_stopped(), that
just do the opposed action of this function. According to this, is it
better to another function to nohz_balance_leave_idle()?
Or keep their current name?

Thanks

Re: [PATCH 1/2] nohz: clean up select_nohz_load_balancer()

[Suresh Siddha]

On Tue, 2012-09-11 at 09:27 +0800, Alex Shi wrote:
> On 09/10/2012 11:26 PM, Peter Zijlstra wrote:
> 
> > On Mon, 2012-09-10 at 15:10 +0800, Alex Shi wrote:
> >> There is no load_balancer to be selected now. It just set state of
> >> nohz tick stopping.
> >>
> >> So rename the function, pass the 'cpu' from parameter and then
> >> remove the useless calling from tick_nohz_restart_sched_tick().
> > 
> > Please check who wrote the code you're patching and attempt to CC them
> > as well, in this case Venki and Suresh.
> 
> 
> Thanks! will care about this from now on.
> 
> > 
> > I think the patch is fine, although I think we could have picked a
> > better name, how about nohz_balance_enter_idle() ?
> 
> 
> nohz_balance_enter_idle is good a name too. but I name it as
> set_nohz_tick_stopped, since there is a clear_nohz_tick_stopped(), that
> just do the opposed action of this function. According to this, is it
> better to another function to nohz_balance_leave_idle()?
> Or keep their current name?
> 

Yes that will be more appropriate name.

Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>

Re: [PATCH 2/2] sched: trigger_load_balance clean up

[Suresh Siddha]

On Mon, 2012-09-10 at 15:10 +0800, Alex Shi wrote:
> Remove a redundant check for on_null_domain(cpu), and rerange the code
> that make it more readable.

hmm, but we are now doing the on_null_domain() check always,
irrespective of whether we need the load balance or not.

do we really need the on_null_domain() check there? What happens if we
just remove it?

thanks,
suresh

> 
> Signed-off-by: Alex Shi <alex.shi@intel.com>
> ---
>  kernel/sched/fair.c |    8 +++++---
>  1 files changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 5bbc4bf..529092d 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -4934,11 +4934,13 @@ static inline int on_null_domain(int cpu)
>  void trigger_load_balance(struct rq *rq, int cpu)
>  {
>  	/* Don't need to rebalance while attached to NULL domain */
> -	if (time_after_eq(jiffies, rq->next_balance) &&
> -	    likely(!on_null_domain(cpu)))
> +	if (unlikely(on_null_domain(cpu)))
> +		return;
> +
> +	if (time_after_eq(jiffies, rq->next_balance))
>  		raise_softirq(SCHED_SOFTIRQ);
>  #ifdef CONFIG_NO_HZ
> -	if (nohz_kick_needed(rq, cpu) && likely(!on_null_domain(cpu)))
> +	if (nohz_kick_needed(rq, cpu))
>  		nohz_balancer_kick(cpu);
>  #endif
>  }

Re: [PATCH 2/2] sched: trigger_load_balance clean up

[Alex Shi]

On 09/12/2012 02:36 AM, Suresh Siddha wrote:

> On Mon, 2012-09-10 at 15:10 +0800, Alex Shi wrote:
>> Remove a redundant check for on_null_domain(cpu), and rerange the code
>> that make it more readable.
> 
> hmm, but we are now doing the on_null_domain() check always,
> irrespective of whether we need the load balance or not.
> 
> do we really need the on_null_domain() check there? What happens if we
> just remove it?


A very very simple try can not show removing causes crash. But as to
RCU details, I don't know. :(

CC to Paul

> 
> thanks,
> suresh
> 
>>
>> Signed-off-by: Alex Shi <alex.shi@intel.com>
>> ---
>>  kernel/sched/fair.c |    8 +++++---
>>  1 files changed, 5 insertions(+), 3 deletions(-)
>>
>> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
>> index 5bbc4bf..529092d 100644
>> --- a/kernel/sched/fair.c
>> +++ b/kernel/sched/fair.c
>> @@ -4934,11 +4934,13 @@ static inline int on_null_domain(int cpu)
>>  void trigger_load_balance(struct rq *rq, int cpu)
>>  {
>>  	/* Don't need to rebalance while attached to NULL domain */
>> -	if (time_after_eq(jiffies, rq->next_balance) &&
>> -	    likely(!on_null_domain(cpu)))
>> +	if (unlikely(on_null_domain(cpu)))
>> +		return;
>> +
>> +	if (time_after_eq(jiffies, rq->next_balance))
>>  		raise_softirq(SCHED_SOFTIRQ);
>>  #ifdef CONFIG_NO_HZ
>> -	if (nohz_kick_needed(rq, cpu) && likely(!on_null_domain(cpu)))
>> +	if (nohz_kick_needed(rq, cpu))
>>  		nohz_balancer_kick(cpu);
>>  #endif
>>  }
> 
> 

Re: [PATCH 2/2] sched: trigger_load_balance clean up

[Suresh Siddha]

On Wed, 2012-09-12 at 15:58 +0800, Alex Shi wrote:
> On 09/12/2012 02:36 AM, Suresh Siddha wrote:
> 
> > On Mon, 2012-09-10 at 15:10 +0800, Alex Shi wrote:
> >> Remove a redundant check for on_null_domain(cpu), and rerange the code
> >> that make it more readable.
> > 
> > hmm, but we are now doing the on_null_domain() check always,
> > irrespective of whether we need the load balance or not.
> > 
> > do we really need the on_null_domain() check there? What happens if we
> > just remove it?
> 
> 
> A very very simple try can not show removing causes crash. But as to
> RCU details, I don't know. :(
> 

So the right way to approach the issue is to do couple of "git blame"
and see who added that code. My check shows 

commit 8a0be9ef8225638d26b455788f988c8f84ce9e75
Author: Frederic Weisbecker <fweisbec@gmail.com>
Date:   Thu Mar 5 01:27:02 2009 +0100

    sched: don't rebalance if attached on NULL domain

And the changelog explains that it has to do with avoiding unnecessary
loadbalances (triggered by softirq) for a SMP kernel on a UP system and
actually has nothing to do with RCU per-say (as the load balancer
already takes the rcu locks etc before traversing the scheduler-domain).

And the second on_null_domain() in that function is added by Venki and
me, probably by mistake. As the nohz_kick_needed() will never return
true for the SMP kernel running on a UP system.

So please just remove the second on_null_domain() check in that function
instead of consolidating both the usages and include the above info in
the changelog.

thanks,
suresh

> > 
> > thanks,
> > suresh
> > 
> >>
> >> Signed-off-by: Alex Shi <alex.shi@intel.com>
> >> ---
> >>  kernel/sched/fair.c |    8 +++++---
> >>  1 files changed, 5 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> >> index 5bbc4bf..529092d 100644
> >> --- a/kernel/sched/fair.c
> >> +++ b/kernel/sched/fair.c
> >> @@ -4934,11 +4934,13 @@ static inline int on_null_domain(int cpu)
> >>  void trigger_load_balance(struct rq *rq, int cpu)
> >>  {
> >>  	/* Don't need to rebalance while attached to NULL domain */
> >> -	if (time_after_eq(jiffies, rq->next_balance) &&
> >> -	    likely(!on_null_domain(cpu)))
> >> +	if (unlikely(on_null_domain(cpu)))
> >> +		return;
> >> +
> >> +	if (time_after_eq(jiffies, rq->next_balance))
> >>  		raise_softirq(SCHED_SOFTIRQ);
> >>  #ifdef CONFIG_NO_HZ
> >> -	if (nohz_kick_needed(rq, cpu) && likely(!on_null_domain(cpu)))
> >> +	if (nohz_kick_needed(rq, cpu))
> >>  		nohz_balancer_kick(cpu);
> >>  #endif
> >>  }
> > 
> > 
> 
> 

Re: [PATCH 1/2] nohz: clean up select_nohz_load_balancer()

[Peter Zijlstra]

On Tue, 2012-09-11 at 11:33 -0700, Suresh Siddha wrote:
> > nohz_balance_enter_idle is good a name too. but I name it as
> > set_nohz_tick_stopped, since there is a clear_nohz_tick_stopped(), that
> > just do the opposed action of this function. According to this, is it
> > better to another function to nohz_balance_leave_idle()?
> > Or keep their current name?
> > 
> 
> Yes that will be more appropriate name.

I've made it:

  nohz_balance_{enter,exit}_idle()

Most of the nohz stuff has the {enter,exit}.

[tip:sched/core] sched/nohz: Clean up select_nohz_load_balancer()

[tip-bot for Alex Shi]

Commit-ID:  c1cc017c59c44d9ede7003631c43adc0cfdce2f9
Gitweb:     http://git.kernel.org/tip/c1cc017c59c44d9ede7003631c43adc0cfdce2f9
Author:     Alex Shi <alex.shi@intel.com>
AuthorDate: Mon, 10 Sep 2012 15:10:58 +0800
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 13 Sep 2012 16:52:05 +0200

sched/nohz: Clean up select_nohz_load_balancer()

There is no load_balancer to be selected now. It just sets the
state of the nohz tick to stop.

So rename the function, pass the 'cpu' as a parameter and then
remove the useless call from tick_nohz_restart_sched_tick().

[ s/set_nohz_tick_stopped/nohz_balance_enter_idle/g
  s/clear_nohz_tick_stopped/nohz_balance_exit_idle/g ]
Signed-off-by: Alex Shi <alex.shi@intel.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1347261059-24747-1-git-send-email-alex.shi@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 include/linux/sched.h    |    4 ++--
 kernel/sched/fair.c      |   25 ++++++++++---------------
 kernel/time/tick-sched.c |    3 +--
 3 files changed, 13 insertions(+), 19 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 60e5e38..8c38df0 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -273,11 +273,11 @@ extern void init_idle_bootup_task(struct task_struct *idle);
 extern int runqueue_is_locked(int cpu);
 
 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
-extern void select_nohz_load_balancer(int stop_tick);
+extern void nohz_balance_enter_idle(int cpu);
 extern void set_cpu_sd_state_idle(void);
 extern int get_nohz_timer_target(void);
 #else
-static inline void select_nohz_load_balancer(int stop_tick) { }
+static inline void nohz_balance_enter_idle(int cpu) { }
 static inline void set_cpu_sd_state_idle(void) { }
 #endif
 
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 9ae3a5b..de596a2 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4603,7 +4603,7 @@ static void nohz_balancer_kick(int cpu)
 	return;
 }
 
-static inline void clear_nohz_tick_stopped(int cpu)
+static inline void nohz_balance_exit_idle(int cpu)
 {
 	if (unlikely(test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))) {
 		cpumask_clear_cpu(cpu, nohz.idle_cpus_mask);
@@ -4643,28 +4643,23 @@ void set_cpu_sd_state_idle(void)
 }
 
 /*
- * This routine will record that this cpu is going idle with tick stopped.
+ * This routine will record that the cpu is going idle with tick stopped.
  * This info will be used in performing idle load balancing in the future.
  */
-void select_nohz_load_balancer(int stop_tick)
+void nohz_balance_enter_idle(int cpu)
 {
-	int cpu = smp_processor_id();
-
 	/*
 	 * If this cpu is going down, then nothing needs to be done.
 	 */
 	if (!cpu_active(cpu))
 		return;
 
-	if (stop_tick) {
-		if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))
-			return;
+	if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))
+		return;
 
-		cpumask_set_cpu(cpu, nohz.idle_cpus_mask);
-		atomic_inc(&nohz.nr_cpus);
-		set_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu));
-	}
-	return;
+	cpumask_set_cpu(cpu, nohz.idle_cpus_mask);
+	atomic_inc(&nohz.nr_cpus);
+	set_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu));
 }
 
 static int __cpuinit sched_ilb_notifier(struct notifier_block *nfb,
@@ -4672,7 +4667,7 @@ static int __cpuinit sched_ilb_notifier(struct notifier_block *nfb,
 {
 	switch (action & ~CPU_TASKS_FROZEN) {
 	case CPU_DYING:
-		clear_nohz_tick_stopped(smp_processor_id());
+		nohz_balance_exit_idle(smp_processor_id());
 		return NOTIFY_OK;
 	default:
 		return NOTIFY_DONE;
@@ -4833,7 +4828,7 @@ static inline int nohz_kick_needed(struct rq *rq, int cpu)
 	* busy tick after returning from idle, we will update the busy stats.
 	*/
 	set_cpu_sd_state_busy();
-	clear_nohz_tick_stopped(cpu);
+	nohz_balance_exit_idle(cpu);
 
 	/*
 	 * None are in tickless mode and hence no need for NOHZ idle load
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 3a9e5d5..1a5ee90 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -372,7 +372,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
 		 * the scheduler tick in nohz_restart_sched_tick.
 		 */
 		if (!ts->tick_stopped) {
-			select_nohz_load_balancer(1);
+			nohz_balance_enter_idle(cpu);
 			calc_load_enter_idle();
 
 			ts->last_tick = hrtimer_get_expires(&ts->sched_timer);
@@ -569,7 +569,6 @@ static void tick_nohz_restart(struct tick_sched *ts, ktime_t now)
 static void tick_nohz_restart_sched_tick(struct tick_sched *ts, ktime_t now)
 {
 	/* Update jiffies first */
-	select_nohz_load_balancer(0);
 	tick_do_update_jiffies64(now);
 	update_cpu_load_nohz();