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Date:   Tue, 1 Aug 2023 10:00:30 -0400
From:   Steven Rostedt <rostedt@goodmis.org>
To:     Yajun Deng <yajun.deng@linux.dev>
Cc:     mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com,
        vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
        bsegall@google.com, mgorman@suse.de, bristot@redhat.com,
        vschneid@redhat.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] sched/rt: move back to RT_GROUP_SCHED and rename it
 child
Message-ID: <20230801100030.5efec7e2@gandalf.local.home>
In-Reply-To: <20230801062714.3424299-1-yajun.deng@linux.dev>
References: <20230801062714.3424299-1-yajun.deng@linux.dev>
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On Tue,  1 Aug 2023 14:27:14 +0800
Yajun Deng <yajun.deng@linux.dev> wrote:

> @@ -228,13 +228,10 @@ void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
>  	if (!rt_se)
>  		return;
>  
> -	if (!parent)
> -		rt_se->rt_rq = &rq->rt;
> -	else
> -		rt_se->rt_rq = parent->my_q;
> -
> +	rt_se->rt_rq = parent->my_q;

So when this is called with parent = NULL, this will crash?

-- Steve

>  	rt_se->my_q = rt_rq;
>  	rt_se->parent = parent;
> +	parent->child = rt_se;
>  	INIT_LIST_HEAD(&rt_se->run_list);
>  }
>