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Subject: Re: [PATCH V3 2/3] sched/deadline: Throttle a constrained deadline
 task activated after the deadline
To: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>
References: <cover.1488271007.git.bristot@redhat.com>
 <5b6fa3cd9da84b8883afc169f44df247b551a4df.1488271007.git.bristot@redhat.com>
Cc: Juri Lelli <juri.lelli@arm.com>,
        Tommaso Cucinotta <tommaso.cucinotta@sssup.it>,
        Luca Abeni <luca.abeni@santannapisa.it>,
        Steven Rostedt <rostedt@goodmis.org>, Mike Galbraith <efault@gmx.de>,
        Romulo Silva de Oliveira <romulo.deoliveira@ufsc.br>
From: Daniel Bristot de Oliveira <bristot@redhat.com>
Message-ID: <43aa3b8c-5f5a-50f9-0d3d-aac86c5fcd3f@redhat.com>
Date: Tue, 28 Feb 2017 19:19:45 +0100
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On 02/28/2017 11:07 AM, Daniel Bristot de Oliveira wrote:
> +	if (!pi_se->dl_throttled && dl_is_constrained(pi_se))
> +		dl_check_constrained_dl(pi_se);
> +

me--, it should be &p->dl, not pi_se. This is not causing problems in
the test case because pi_se = &p->dl, but this would be a problem if we
were activating the task in a PI case: it would check the pi-waiter, not
the task being awakened (p).

In the dl_check_constrained_dl(), the patch is already avoiding
throttling if the task is "dl_boosted." So it is ready to avoid
throttling the task in the PI control.

Cooking a v4, sorry for the noise.

-- Daniel