From: Scott Wood <scottwood@freescale.com>
To: Alexander Graf <agraf@suse.de>
Cc: "qemu-ppc@nongnu.org list:PowerPC" <qemu-ppc@nongnu.org>,
qemu-devel Developers <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] [PATCH] PPC: E500: Generate device tree on reset
Date: Tue, 23 Jul 2013 14:38:48 -0500 [thread overview]
Message-ID: <1374608328.15592.36@snotra> (raw)
In-Reply-To: <1374506897-41089-1-git-send-email-agraf@suse.de> (from agraf@suse.de on Mon Jul 22 10:28:17 2013)
On 07/22/2013 10:28:17 AM, Alexander Graf wrote:
> Today we generate the device tree once on machine initialization and
> then
> store the finalized blob in memory to reload it on reset.
>
> This is bad for 2 reasons. First we potentially waste a bunch of RAM
> for no
> good reason, as we have all information required to regenerate the
> device
> tree available anyways.
>
> The second reason is even more important. On machine init when we
> generate
> the device tree for the first time, we don't have all of the devices
> fully
> initialized yet. But the device tree needs to potentially walk
> devices to
> put information about them into the device tree.
If you can't produce the entire device tree at init time, how can you
calculate its size with a dry run?
Device trees are generally pretty small; couldn't we just set a maximum
size and allocate that much space?
-Scott
next prev parent reply other threads:[~2013-07-23 19:39 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-22 15:28 [Qemu-devel] [PATCH] PPC: E500: Generate device tree on reset Alexander Graf
2013-07-23 19:38 ` Scott Wood [this message]
2013-07-23 21:15 ` Alexander Graf
2013-07-23 21:19 ` Scott Wood
2013-07-23 21:44 ` Alexander Graf
2013-07-23 21:55 ` Scott Wood
2013-07-23 21:56 ` Alexander Graf
2013-07-24 2:58 ` Alexey Kardashevskiy
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