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Date:   Fri, 24 Apr 2020 09:55:02 -0400
From:   Steven Rostedt <rostedt@goodmis.org>
To:     Hillf Danton <hdanton@sina.com>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@kernel.org>,
        lkml <linux-kernel@vger.kernel.org>,
        Mike Galbraith <efault@gmx.de>,
        Mel Gorman <mgorman@techsingularity.net>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Phil Auld <pauld@redhat.com>,
        Valentin Schneider <valentin.schneider@arm.com>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Mark Rutland <mark.rutland@arm.com>
Subject: Re: [PATCH 1/4] sched: set p->prio reguardless of p->mm
Message-ID: <20200424095502.0063e857@gandalf.local.home>
In-Reply-To: <20200424043041.15084-1-hdanton@sina.com>
References: <20200424041832.11364-1-hdanton@sina.com>
        <20200424043041.15084-1-hdanton@sina.com>
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On Fri, 24 Apr 2020 12:30:41 +0800
Hillf Danton <hdanton@sina.com> wrote:

> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -4795,14 +4795,6 @@ recheck:
>  	if (attr->sched_flags & ~(SCHED_FLAG_ALL | SCHED_FLAG_SUGOV))
>  		return -EINVAL;
>  
> -	/*
> -	 * Valid priorities for SCHED_FIFO and SCHED_RR are
> -	 * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL,
> -	 * SCHED_BATCH and SCHED_IDLE is 0.
> -	 */
> -	if ((p->mm && attr->sched_priority > MAX_USER_RT_PRIO-1) ||
> -	    (!p->mm && attr->sched_priority > MAX_RT_PRIO-1))
> -		return -EINVAL;


So if someone passes in sched_priority > MAX_RT_PRIO-1, where does it get
checked?

-- Steve

>  	if ((dl_policy(policy) && !__checkparam_dl(attr)) ||
>  	    (rt_policy(policy) != (attr->sched_priority != 0)))
>  		return -EINVAL;