[v1] sched/fair: Remove cfs_rq::nr_spread_over and cfs_rq::exec_clock

[PATCH] sched/fair: Remove cfs_rq::nr_spread_over and cfs_rq::exec_clock

Posted by Chuyi Zhou 1 year, 5 months ago

cfs_rq::nr_spread_over and cfs_rq::exec_clock are not used anymore in
eevdf. Remove them from struct cfs_rq.

Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
---
 kernel/sched/debug.c | 4 ----
 kernel/sched/sched.h | 6 ------
 2 files changed, 10 deletions(-)

diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index c1eb9a1afd13..90c4a9998377 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -641,8 +641,6 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
 	SEQ_printf(m, "\n");
 	SEQ_printf(m, "cfs_rq[%d]:\n", cpu);
 #endif
-	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "exec_clock",
-			SPLIT_NS(cfs_rq->exec_clock));
 
 	raw_spin_rq_lock_irqsave(rq, flags);
 	root = __pick_root_entity(cfs_rq);
@@ -669,8 +667,6 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
 			SPLIT_NS(right_vruntime));
 	spread = right_vruntime - left_vruntime;
 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "spread", SPLIT_NS(spread));
-	SEQ_printf(m, "  .%-30s: %d\n", "nr_spread_over",
-			cfs_rq->nr_spread_over);
 	SEQ_printf(m, "  .%-30s: %d\n", "nr_running", cfs_rq->nr_running);
 	SEQ_printf(m, "  .%-30s: %d\n", "h_nr_running", cfs_rq->h_nr_running);
 	SEQ_printf(m, "  .%-30s: %d\n", "idle_nr_running",
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 4c36cc680361..8a071022bdec 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -599,7 +599,6 @@ struct cfs_rq {
 	s64			avg_vruntime;
 	u64			avg_load;
 
-	u64			exec_clock;
 	u64			min_vruntime;
 #ifdef CONFIG_SCHED_CORE
 	unsigned int		forceidle_seq;
@@ -619,10 +618,6 @@ struct cfs_rq {
 	struct sched_entity	*curr;
 	struct sched_entity	*next;
 
-#ifdef	CONFIG_SCHED_DEBUG
-	unsigned int		nr_spread_over;
-#endif
-
 #ifdef CONFIG_SMP
 	/*
 	 * CFS load tracking
@@ -1158,7 +1153,6 @@ struct rq {
 	/* latency stats */
 	struct sched_info	rq_sched_info;
 	unsigned long long	rq_cpu_time;
-	/* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
 
 	/* sys_sched_yield() stats */
 	unsigned int		yld_count;
-- 
2.20.1

Re: [PATCH] sched/fair: Remove cfs_rq::nr_spread_over and cfs_rq::exec_clock

Posted by Vishal Chourasia 1 year, 5 months ago

On Tue, Jul 16, 2024 at 11:06:34PM +0800, Chuyi Zhou wrote:
> cfs_rq::nr_spread_over and cfs_rq::exec_clock are not used anymore in
> eevdf. Remove them from struct cfs_rq.
> 

nr_spread_over tracks the number of instances where the difference
between a scheduling entity's virtual runtime and the minimum virtual
runtime in the runqueue exceeds three times the scheduler latency,
indicating significant disparity in task scheduling.  
Commit that removed its usage: 5e963f2bd: sched/fair: Commit to EEVDF


cfs_rq->exec_clock was used to account for time spent executing tasks.
Commit that removed its usage: 5d69eca542ee1 sched: Unify runtime
accounting across classes

> Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>

Acked-by: Vishal Chourasia <vishalc@linux.ibm.com>
> ---
>  kernel/sched/debug.c | 4 ----
>  kernel/sched/sched.h | 6 ------
>  2 files changed, 10 deletions(-)
> 
> diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
> index c1eb9a1afd13..90c4a9998377 100644
> --- a/kernel/sched/debug.c
> +++ b/kernel/sched/debug.c
> @@ -641,8 +641,6 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
>  	SEQ_printf(m, "\n");
>  	SEQ_printf(m, "cfs_rq[%d]:\n", cpu);
>  #endif
> -	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "exec_clock",
> -			SPLIT_NS(cfs_rq->exec_clock));
>  
>  	raw_spin_rq_lock_irqsave(rq, flags);
>  	root = __pick_root_entity(cfs_rq);
> @@ -669,8 +667,6 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
>  			SPLIT_NS(right_vruntime));
>  	spread = right_vruntime - left_vruntime;
>  	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "spread", SPLIT_NS(spread));
> -	SEQ_printf(m, "  .%-30s: %d\n", "nr_spread_over",
> -			cfs_rq->nr_spread_over);
>  	SEQ_printf(m, "  .%-30s: %d\n", "nr_running", cfs_rq->nr_running);
>  	SEQ_printf(m, "  .%-30s: %d\n", "h_nr_running", cfs_rq->h_nr_running);
>  	SEQ_printf(m, "  .%-30s: %d\n", "idle_nr_running",
> diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
> index 4c36cc680361..8a071022bdec 100644
> --- a/kernel/sched/sched.h
> +++ b/kernel/sched/sched.h
> @@ -599,7 +599,6 @@ struct cfs_rq {
>  	s64			avg_vruntime;
>  	u64			avg_load;
>  
> -	u64			exec_clock;
>  	u64			min_vruntime;
>  #ifdef CONFIG_SCHED_CORE
>  	unsigned int		forceidle_seq;
> @@ -619,10 +618,6 @@ struct cfs_rq {
>  	struct sched_entity	*curr;
>  	struct sched_entity	*next;
>  
> -#ifdef	CONFIG_SCHED_DEBUG
> -	unsigned int		nr_spread_over;
> -#endif
> -
>  #ifdef CONFIG_SMP
>  	/*
>  	 * CFS load tracking
> @@ -1158,7 +1153,6 @@ struct rq {
>  	/* latency stats */
>  	struct sched_info	rq_sched_info;
>  	unsigned long long	rq_cpu_time;
> -	/* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
>  
>  	/* sys_sched_yield() stats */
>  	unsigned int		yld_count;
> -- 
> 2.20.1
>

Re: [PATCH] sched/fair: Remove cfs_rq::nr_spread_over and cfs_rq::exec_clock

Posted by Chengming Zhou 1 year, 5 months ago

On 2024/7/17 19:07, Vishal Chourasia wrote:
> On Tue, Jul 16, 2024 at 11:06:34PM +0800, Chuyi Zhou wrote:
>> cfs_rq::nr_spread_over and cfs_rq::exec_clock are not used anymore in
>> eevdf. Remove them from struct cfs_rq.
>>
> 
> nr_spread_over tracks the number of instances where the difference
> between a scheduling entity's virtual runtime and the minimum virtual
> runtime in the runqueue exceeds three times the scheduler latency,
> indicating significant disparity in task scheduling.
> Commit that removed its usage: 5e963f2bd: sched/fair: Commit to EEVDF
> 
> 
> cfs_rq->exec_clock was used to account for time spent executing tasks.
> Commit that removed its usage: 5d69eca542ee1 sched: Unify runtime
> accounting across classes
> 
>> Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
> 
> Acked-by: Vishal Chourasia <vishalc@linux.ibm.com>

Looks good to me! Maybe it's better to add these to your changelog.

Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>

Thanks.

>> ---
>>   kernel/sched/debug.c | 4 ----
>>   kernel/sched/sched.h | 6 ------
>>   2 files changed, 10 deletions(-)
>>
>> diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
>> index c1eb9a1afd13..90c4a9998377 100644
>> --- a/kernel/sched/debug.c
>> +++ b/kernel/sched/debug.c
>> @@ -641,8 +641,6 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
>>   	SEQ_printf(m, "\n");
>>   	SEQ_printf(m, "cfs_rq[%d]:\n", cpu);
>>   #endif
>> -	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "exec_clock",
>> -			SPLIT_NS(cfs_rq->exec_clock));
>>   
>>   	raw_spin_rq_lock_irqsave(rq, flags);
>>   	root = __pick_root_entity(cfs_rq);
>> @@ -669,8 +667,6 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
>>   			SPLIT_NS(right_vruntime));
>>   	spread = right_vruntime - left_vruntime;
>>   	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "spread", SPLIT_NS(spread));
>> -	SEQ_printf(m, "  .%-30s: %d\n", "nr_spread_over",
>> -			cfs_rq->nr_spread_over);
>>   	SEQ_printf(m, "  .%-30s: %d\n", "nr_running", cfs_rq->nr_running);
>>   	SEQ_printf(m, "  .%-30s: %d\n", "h_nr_running", cfs_rq->h_nr_running);
>>   	SEQ_printf(m, "  .%-30s: %d\n", "idle_nr_running",
>> diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
>> index 4c36cc680361..8a071022bdec 100644
>> --- a/kernel/sched/sched.h
>> +++ b/kernel/sched/sched.h
>> @@ -599,7 +599,6 @@ struct cfs_rq {
>>   	s64			avg_vruntime;
>>   	u64			avg_load;
>>   
>> -	u64			exec_clock;
>>   	u64			min_vruntime;
>>   #ifdef CONFIG_SCHED_CORE
>>   	unsigned int		forceidle_seq;
>> @@ -619,10 +618,6 @@ struct cfs_rq {
>>   	struct sched_entity	*curr;
>>   	struct sched_entity	*next;
>>   
>> -#ifdef	CONFIG_SCHED_DEBUG
>> -	unsigned int		nr_spread_over;
>> -#endif
>> -
>>   #ifdef CONFIG_SMP
>>   	/*
>>   	 * CFS load tracking
>> @@ -1158,7 +1153,6 @@ struct rq {
>>   	/* latency stats */
>>   	struct sched_info	rq_sched_info;
>>   	unsigned long long	rq_cpu_time;
>> -	/* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
>>   
>>   	/* sys_sched_yield() stats */
>>   	unsigned int		yld_count;
>> -- 
>> 2.20.1
>>

Re: [PATCH] sched/fair: Remove cfs_rq::nr_spread_over and cfs_rq::exec_clock

Posted by Chuyi Zhou 1 year, 5 months ago


在 2024/7/17 19:25, Chengming Zhou 写道:
> On 2024/7/17 19:07, Vishal Chourasia wrote:
>> On Tue, Jul 16, 2024 at 11:06:34PM +0800, Chuyi Zhou wrote:
>>> cfs_rq::nr_spread_over and cfs_rq::exec_clock are not used anymore in
>>> eevdf. Remove them from struct cfs_rq.
>>>
>>
>> nr_spread_over tracks the number of instances where the difference
>> between a scheduling entity's virtual runtime and the minimum virtual
>> runtime in the runqueue exceeds three times the scheduler latency,
>> indicating significant disparity in task scheduling.
>> Commit that removed its usage: 5e963f2bd: sched/fair: Commit to EEVDF
>>
>>
>> cfs_rq->exec_clock was used to account for time spent executing tasks.
>> Commit that removed its usage: 5d69eca542ee1 sched: Unify runtime
>> accounting across classes
>>
>>> Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
>>
>> Acked-by: Vishal Chourasia <vishalc@linux.ibm.com>
> 
> Looks good to me! Maybe it's better to add these to your changelog.
> 
> Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
> 
> Thanks.



Thanks, will do this later.