From mboxrd@z Thu Jan  1 00:00:00 1970
From: Peter Zijlstra <peterz@infradead.org>
Subject: Re: Changing Kernel thread priorities
Date: Tue, 07 Jun 2011 00:36:01 +0200
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Cc: Monica Puig-Pey <puigpeym@unican.es>,
	Rolando Martins <rolando.martins@gmail.com>,
	linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org,
	tglx <tglx@linutronix.de>
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"Monica Puig-Pey" <puigpeym@unican.es> wrote:
> 
> I need to change the priority from inside the driver, when creating the 
> kernel thread.

No you don't. How does you driver know about what priority is correct
wrt all the other running RT tasks on the system?

Determining the right priority in a fixed priority scheduling system is
a system wide problem, nobody but the administrator can possibly even
begin to solve it.

There's a reason all RT irq threads are started at 50, its plain
impossible to do better.