linux-kernel - Re: [External] Re: [PATCH v2 2/2] sched/dl: Remove some comments and adjust code in push_dl

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Message-ID: <10afde23-7ef9-1733-f2ce-a697fcab24f2@bytedance.com>
Date:   Tue, 26 Apr 2022 16:01:13 +0800
From:   Hao Jia <jiahao.os@...edance.com>
To:     Dietmar Eggemann <dietmar.eggemann@....com>, mingo@...hat.com,
        peterz@...radead.org, juri.lelli@...hat.com,
        vincent.guittot@...aro.org, rostedt@...dmis.org,
        bsegall@...gle.com, mgorman@...e.de, bristot@...hat.com
Cc:     linux-kernel@...r.kernel.org
Subject: Re: [External] Re: [PATCH v2 2/2] sched/dl: Remove some comments and
 adjust code in push_dl_task



On 2022/4/26 Dietmar Eggemann wrote:
> On 22/04/2022 11:09, Hao Jia wrote:
> 
> Nitpick: I would change the message slightly into something like:
> 
> sched/deadline: Remove superfluous rq clock update in push_dl_task()
> 

I will do it in patch v3.
Thanks.


>> The change to call update_rq_clock() before activate_task()
>> commit 840d719604b0 ("sched/deadline: Update rq_clock of later_rq
>> when pushing a task") is no longer needed since commit f4904815f97a
>> ("sched/deadline: Fix double accounting of rq/running bw in push & pull")
>> removed the add_running_bw() before the activate_task().
>>
>> So we remove some comments that are no longer needed and update
>> rq clock in activate_task().
>>
>> Signed-off-by: Hao Jia <jiahao.os@...edance.com>
>> ---
>>   kernel/sched/deadline.c | 8 +-------
>>   1 file changed, 1 insertion(+), 7 deletions(-)
>>
>> diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
>> index fb4255ae0b2c..8eb694ed7ac1 100644
>> --- a/kernel/sched/deadline.c
>> +++ b/kernel/sched/deadline.c
>> @@ -2319,13 +2319,7 @@ static int push_dl_task(struct rq *rq)
>>   
>>   	deactivate_task(rq, next_task, 0);
>>   	set_task_cpu(next_task, later_rq->cpu);
>> -
>> -	/*
>> -	 * Update the later_rq clock here, because the clock is used
>> -	 * by the cpufreq_update_util() inside __add_running_bw().
>> -	 */
>> -	update_rq_clock(later_rq);
>> -	activate_task(later_rq, next_task, ENQUEUE_NOCLOCK);
>> +	activate_task(later_rq, next_task, 0);
>>   	ret = 1;
>>   
>>   	resched_curr(later_rq);
> 
> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@....com>