From mboxrd@z Thu Jan  1 00:00:00 1970
From: Oliver Neukum <oneukum@suse.com>
Subject: Re: Should suspend plug low-level devices?
Date: Thu, 17 Mar 2016 11:29:26 +0100
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To: Jiri Kosina <jikos@kernel.org>
Cc: Peter Chen <hzpeterchen@gmail.com>, "Rafael J. Wysocki" <rafael@kernel.org>, Tejun Heo <tj@kernel.org>, Florian Mickler <florian@mickler.org>, Alan Stern <stern@rowland.harvard.edu>, Jan Kara <jack@suse.cz>, Linux-pm mailing list <linux-pm@vger.kernel.org>

On Thu, 2016-03-17 at 11:20 +0100, Jiri Kosina wrote:
> On Thu, 17 Mar 2016, Oliver Neukum wrote:
> 
> > Yes, but you are making the assumption that only the kthreads a driver
> > started are causing IO to it. That is a tall one.
> > 
> > - logging
> > - network
> > - device discovery on busses
> > - detection of media
> > - knfsd
> > 
> > All these things cause IO and I probably forgot some. Defined semantics 
> > for the threads a driver starts are a good idea, but it leaves out the 
> > really hard cases.
> 
> So you named only one specific kthread here (knfsd), so let's focus on 
> that one. Where is that one currently being frozen during suspend?

In svc_recv()

That concentration, however, is problematic. We can target anything
specific, but the point is, do we know what is running?

	Regards
		Oliver