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Date: Thu, 14 Jan 2016 20:56:51 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: Luca Abeni <luca.abeni@unitn.it>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
        Juri Lelli <juri.lelli@arm.com>
Subject: Re: [RFC 7/8] Make GRUB a task's flag
Message-ID: <20160114195651.GG6357@twins.programming.kicks-ass.net>
References: <1452785094-3086-1-git-send-email-luca.abeni@unitn.it>
 <1452785094-3086-8-git-send-email-luca.abeni@unitn.it>
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On Thu, Jan 14, 2016 at 04:24:52PM +0100, Luca Abeni wrote:
> +++ b/include/uapi/linux/sched.h
> @@ -48,5 +48,6 @@
>   * For the sched_{set,get}attr() calls
>   */
>  #define SCHED_FLAG_RESET_ON_FORK	0x01
> +#define SCHED_FLAG_RECLAIM		0x02

With an eye towards unpriv usage of SCHED_DEADLINE, this isn't something
we could allow unpriv tasks, right? Since (IIRC) GRUB will allow eating
all !deadline time.

Something with an average runtime/budget that also puts limits on the
max (say 2*avg) would be far more amenable to be exposed to unpriv
tasks, except since that would directly result in an average tardiness
bound this might be non-trivial to combine with tasks not opting for
this.