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Subject: Re: pci_get_dev_by_id() from interrupt handlers
From: Peter Zijlstra <peterz@infradead.org>
To: Joerg Roedel <joerg.roedel@amd.com>
Cc: Greg KH <greg@kroah.com>, Joerg Roedel <joro@8bytes.org>,
       Jesse Barnes <jbarnes@virtuousgeek.org>, linux-pci@vger.kernel.org,
       linux-kernel@vger.kernel.org
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Date: Wed, 21 Apr 2010 12:46:56 +0200
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On Wed, 2010-04-21 at 12:41 +0200, Joerg Roedel wrote:
> On Wed, Apr 21, 2010 at 12:21:11PM +0200, Peter Zijlstra wrote:
> > On Wed, 2010-04-21 at 12:05 +0200, Joerg Roedel wrote:
> > > 
> > > > Why not do the whole thing in an interrupt task as the whole thing
> > > > sounds like something that shouldn't be done in interrupt context,
> > > > right?  Now that we have this type of functionality, we should take
> > > > advantage of it :)
> > > 
> > > Ok, I think I move the IOMMU interrupt handling to a tasklet.
> > > 
> > tasklet is softirq context, and is not what gregkh was talking about.
> > 
> > You'd still need to change the klist spinlock to be softirq-safe.
> 
> Ah right. Thanks for pointing this out. I couldn't find much about the
> interrupt tasks. Is it about the request_threaded_irq interface? And
> this would be run in the context of a kernel thread, right?

Right, request_threaded_irq() is what was meant, the comment there does
a good job of describing how to use it.