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Subject: Re: On migrate_disable() and latencies
From: Peter Zijlstra <peterz@infradead.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
        linux-rt-users <linux-rt-users@vger.kernel.org>,
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Date: Fri, 22 Jul 2011 16:57:43 +0200
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On Fri, 2011-07-22 at 12:49 +0200, Peter Zijlstra wrote:
> > The scenario is on where you stack N migrate-disable tasks on a run
> > queue (necessarily of increasing priority). Doing this requires all cpus
> > in the system to be as busy, for otherwise the task would simply be
> > moved to another cpu.
> 
> This implies it requires at least nr-cpus^2 tasks to pull this off. 

OK, scrap that, 2*nr-cpus is enough.