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Message-ID: <c5d40522-037d-e324-697b-23e5e4686d58@redhat.com>
Date:   Fri, 26 Aug 2022 09:10:08 +0200
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Subject: Re: [PATCH -next] sched/deadline: Add compare_task_rq helper
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To:     Shang XiaoJing <shangxiaojing@huawei.com>
References: <20220826031143.9501-1-shangxiaojing@huawei.com>
From:   Daniel Bristot de Oliveira <bristot@redhat.com>
Cc:     mingo@redhat.com, peterz@infradead.org, vincent.guittot@linaro.org,
        juri.lelli@redhat.com, dietmar.eggemann@arm.com,
        rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de,
        vschneid@redhat.com, linux-kernel@vger.kernel.org
In-Reply-To: <20220826031143.9501-1-shangxiaojing@huawei.com>
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On 8/26/22 05:11, Shang XiaoJing wrote:
> Wrap repeated code in helper function compare_task_rq, which return true
> if there is no deadline task on the rq at all, or task's deadline
> earlier than the rq.
> 
> Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
> ---
>  kernel/sched/deadline.c | 23 +++++++++++------------
>  1 file changed, 11 insertions(+), 12 deletions(-)
> 
> diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
> index d116d2b9d2f9..4a40a462717c 100644
> --- a/kernel/sched/deadline.c
> +++ b/kernel/sched/deadline.c
> @@ -1810,6 +1810,13 @@ static void yield_task_dl(struct rq *rq)
>  
>  #ifdef CONFIG_SMP

I see the value of this helper, but "compare_task_rq" is making things more confuse.

Choose a more descriptive name, like, dl_task_is_earliest_deadline() ?

> +static inline bool compare_task_rq(struct task_struct *p, struct rq *rq)
> +{
> +	return (!rq->dl.dl_nr_running ||
> +		dl_time_before(p->dl.deadline,
> +			       rq->dl.earliest_dl.curr));
> +}
> +

-- Daniel