Message-ID: <1436170821.8225.1.camel@suse.com>
Subject: Re: [Spice-devel] [RFC PATCH 1/1] Add a usbredir kernel module to
 remotely connect USB devices over IP.
From: Oliver Neukum <oneukum@suse.com>
To: Krzysztof Opasiak <k.opasiak@samsung.com>
Cc: Alan Stern <stern@rowland.harvard.edu>,
        Jeremy White <jwhite@codeweavers.com>,
        Hans de Goede <hdegoede@redhat.com>,
        "Daniel P. Berrange" <berrange@redhat.com>,
        spice-devel@lists.freedesktop.org, linux-usb@vger.kernel.org,
        linux-kernel@vger.kernel.org
Date: Mon, 06 Jul 2015 10:20:21 +0200
In-Reply-To: <55964CFF.1090803@samsung.com>
References: <Pine.LNX.4.44L0.1507021615250.1320-100000@iolanthe.rowland.org>
	 <55964CFF.1090803@samsung.com>
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On Fri, 2015-07-03 at 10:51 +0200, Krzysztof Opasiak wrote:
> Doesn't we have the same problem with functionfs/gadgetfs and
> dummy_hcd? 
> Or with fuse?
> 
> It's a very generic problem for all "virtualized devices" and it is 
> known for quite a long time. This is why many tutorials about swap
> warns 
> that swap should be set up only on real block devices which are fully 
> served in kernel.

Indeed. But the point is that it isn't limited to swap. As you as
a page needs to be laundered the problem exists.
Mmapping a file for write (non private) is enough.

	Regards
		Oliver


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