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Subject: Re: [patch 4/4] genirq: add support for threaded interrupt handlers
From: Peter Zijlstra <peterz@infradead.org>
To: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Steven Rostedt <rostedt@goodmis.org>,
       Arjan van de Ven <arjan@infradead.org>,
       Andrew Morton <akpm@linux-foundation.org>,
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       mingo@elte.hu, jonathan@jonmasters.org
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Date: Mon, 02 Mar 2009 14:21:48 +0100
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On Sat, 2009-02-28 at 14:46 +0100, Stefan Richter wrote:
> > We also tried to bind the IRQ thread to the CPU if it were to run a 
> > softirq. But that too had issues. If the IRQ thread was bound to a CPU and 
> > a higher priority process preempted it, that IRQ handler could not migrate 
> > to another CPU to finish the work. Now the IRQ handler would need to wait 
> > for that high priority process to give up the CPU in order to continue.
> > 
> > The solution is to redesign the softirq code to handle migration.
> 
> Do you mean "redesign the softirq framework" or "redesign the softirq
> framework users"?
> 
> (In the particular case of firewire, the latter should be just fine.)

The latter.