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Date: Thu, 15 May 2008 18:42:06 -0400
From: Jeff Garzik <jeff@garzik.org>
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To: "Brandeburg, Jesse" <jesse.brandeburg@intel.com>
CC: Alan Cox <alan@lxorguk.ukuu.org.uk>,
       Chris Peterson <cpeterso@cpeterso.com>, netdev@vger.kernel.org,
       linux-kernel@vger.kernel.org
Subject: Re: [PATCH] drivers/net: remove network drivers' last few uses of
 IRQF_SAMPLE_RANDOM
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Brandeburg, Jesse wrote:
> we've been hearing rumblings of big customers wanting (maybe requiring)
> wired network drivers from Intel to  advertise this flag.  Jeff have you
> heard of such?
> 
> I think the argument is that a headless system (no keyboard/mouse, no
> soundcard, probably no video) with a libata based driver and a network
> driver without IRQF_SAMPLE_RANDOM has *no* sources of entropy.  In this
> case the argument is very strong for at least *some* source of entropy
> from interrupts so that randomness can get some external input.  Just
> try rebuilding a kernel RPM over an ssh session and you'll see what I
> mean.
> 
> In short, I agree with Alan's IRQF_SAMPLE_DUBIOUS, and know of Linux
> customers who also want the same.


So I guess a good message for customers might be:

Don't depend on an entropy source whose volume decreases as workload and 
network traffic increase.

	Jeff