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Date: Fri, 24 Jul 2009 21:44:43 +0800
Message-ID: <454c71700907240644h7469e2a5sfcb57f202a2e184d@mail.gmail.com>
Subject: Re: report a bug about sched_rt
From: sen wang <wangsen.linux@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: mingo@elte.hu, akpm@linux-foundation.org, kernel@kolivas.org,
       npiggin@suse.de, arjan@infradead.org,
       linux-arm-kernel@lists.arm.linux.org.uk, linux-kernel@vger.kernel.org
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2009/7/24 Peter Zijlstra <peterz@infradead.org>:
> On Fri, 2009-07-24 at 21:26 +0800, sen wang wrote:
>> don't tell me what theory. don't be so doctrinairism! OK?
>> If cpu is free and there is a running state task,how can you scdedule
>> idle task up?
>> I tell you again:we are not talking about a bandwidth of 100% for RT!
>> Bug lies in the bandwidth of (100- X)%.(X<100)
>> even in the time of 100-X,if there is a rt task, you should not idle()
>> the system.
>
> *sigh*
>
> Yes we should. I appreciate that you might assume otherwise, but you're
> wrong. Suppose you have two competing bandwidth groups, which one will
> run over, to what purpose?
>
> Also, your next top post will go to /dev/null.
>


OK !  maybe you has not understand what I said.
It not two competing bandwidth groups. there is a  active group and
another is empty?
How you do?
Why not try it by your hand: empty the fair task, run a rt task,enable
the  bandwidth and
see what will happen!

In many embedded system,idle task will lead to shutdown something, but
the rt task will
assume: when it run, idle will not happen!
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