Date: Tue, 21 Jan 2014 11:28:37 -0500
From: Steven Rostedt <rostedt@goodmis.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Luca Abeni <luca.abeni@unitn.it>, Henrik Austad <henrik@austad.us>,
        Juri Lelli <juri.lelli@gmail.com>, tglx@linutronix.de,
        mingo@redhat.com, oleg@redhat.com, fweisbec@gmail.com,
        darren@dvhart.com, johan.eker@ericsson.com, p.faure@akatech.ch,
        linux-kernel@vger.kernel.org, claudio@evidence.eu.com,
        michael@amarulasolutions.com, fchecconi@gmail.com,
        tommaso.cucinotta@sssup.it, nicola.manica@disi.unitn.it,
        dhaval.giani@gmail.com, hgu1972@gmail.com, paulmck@linux.vnet.ibm.com,
        raistlin@linux.it, insop.song@gmail.com, liming.wang@windriver.com,
        jkacur@redhat.com, harald.gustafsson@ericsson.com,
        vincent.guittot@linaro.org, bruce.ashfield@windriver.com,
        rob@landley.net
Subject: Re: [PATCH] sched/deadline: Add sched_dl documentation
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On Tue, 21 Jan 2014 14:55:59 +0100
Peter Zijlstra <peterz@infradead.org> wrote:


> > >I would strongly urge you not to use that as an example, because its
> > >dead wrong design. An RT thread (be it RR,FIFO or DL) should _NEVER_ do
> > >blocking IO.
> > Well, but it does happen in reality :)
> 
> Yeah, I know, my point was more about not encouraging people to do this
> by explicitly mentioning it.

Unless it is mentioned that this is fine for soft real-time uses, such
as what Luca described (mplayer and possibly Jack). Tools where missing
a deadline does not crash the system, but just reduces quality.

-- Steve
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