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Date: Mon, 11 May 2009 18:55:13 +0100
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Kay Sievers <kay.sievers@vrfy.org>
Cc: Arjan van de Ven <arjan@infradead.org>,
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       Andrew Morton <akpm@linux-foundation.org>,
       Fabio Comolli <fabio.comolli@gmail.com>, Greg KH <greg@kroah.com>,
       linux-kernel@vger.kernel.org
Subject: Re: [patch 00/13] devtmpfs patches
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> The same applies when you leave initiramfs, the in-initramfs udevd
> copy is killed, and the one from the real root is started. You may
> miss events in-between, and need to run a full coldplug again, not
> only to apply the policy, but also to make sure that all nodes are
> there. The policy can run in the background for most things just fine,
> the missing node may cause trouble.

What a strange behaviour. Why not run a single udev instance inside the
tmpfs you are turning into dev and will then attach to the real rootfs
when it appears ? You only need to build /dev once.

> Yeah, and I mentioned many other ways this is useful, to do stuff in
> parallel, to be able to rescue, and to have custom systems which do

But there are lots where it is not - and those you've mentioned where it
might be seem rather stretched at best.