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Date: Thu, 12 Feb 2009 14:23:14 -0800
From: Andrew Morton <akpm@linux-foundation.org>
To: ebiederm@xmission.com (Eric W. Biederman)
Cc: fweisbec@gmail.com, mingo@elte.hu, linux-kernel@vger.kernel.org,
       oleg@redhat.com, travis@sgi.com, a.p.zijlstra@chello.nl,
       rusty@rustcorp.com.au
Subject: Re: +
 work_on_cpu-rewrite-it-to-create-a-kernel-thread-on-demand.patch  added to
 -mm tree
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On Thu, 12 Feb 2009 14:13:06 -0800
ebiederm@xmission.com (Eric W. Biederman) wrote:

> 
> I should follow up and say that the reason I care right now, is I am
> digging into pci hotplug.  One of the issues I'm fighting is that
> currently I appear to need a dedicated kernel thread for each pci
> hotplug slot.  It gets easy to deadlock the kernel hotplugging
> a hotplug controller otherwise.
> 

um, ok, if you say so...

I'd have thought that a short-lived kernel thread would be appropriate,
if poss.  Physical hotplug of a PCI device isn't a high-frequency
operation.

The new-fangled work_on_cpu() could do that, or maybe the new-fangled
kernel/async.c code.