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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Chris Friesen <cbf123@mail.usask.ca>
Cc: kexec@lists.infradead.org,
	Michael Ellerman <michael@ellerman.id.au>,
	Haren Myneni <hbabu@us.ibm.com>,
	Paul Mackerras <paulus@samba.org>,
	linuxppc-dev@lists.ozlabs.org, Vivek Goyal <vgoyal@redhat.com>
Subject: Re: visible memory seems wrong in kexec crash dump kernel
Date: Mon, 15 Jul 2013 09:11:27 +1000	[thread overview]
Message-ID: <1373843487.19894.304.camel@pasglop> (raw)
In-Reply-To: <51E32F76.5070502@mail.usask.ca>

On Sun, 2013-07-14 at 17:08 -0600, Chris Friesen wrote:
> > So for memory starting at 0 it should be memory@0
> 
> There are a fair number of dts files in the kernel tree that don't 
> specify an address for the memory node.
> 
> If the kernel accepts it without an address, it seems logical that kexec 
> should as well.

As long as kexec doesn't start being stupid when there are several nodes
and doesn't pick up the "first one in device-tree order" instead of the
one at 0...

I've been hit by that sort of bugs before (though not specifically in
kexec).

> Or maybe the kernel should just implicitly assume an address of zero and 
> export it as such in /proc/device-tree?

I don't want /proc/device-tree to expose something different than what's in
the actual device-tree, that would be the source for endless horrors.

We already are borderline with the occasional renaming we do in the case of
duplicate name+property...

Cheers,
Ben.



_______________________________________________
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kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

WARNING: multiple messages have this Message-ID (diff)
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Chris Friesen <cbf123@mail.usask.ca>
Cc: kexec@lists.infradead.org, Paul Mackerras <paulus@samba.org>,
	linuxppc-dev@lists.ozlabs.org, Vivek Goyal <vgoyal@redhat.com>
Subject: Re: visible memory seems wrong in kexec crash dump kernel
Date: Mon, 15 Jul 2013 09:11:27 +1000	[thread overview]
Message-ID: <1373843487.19894.304.camel@pasglop> (raw)
In-Reply-To: <51E32F76.5070502@mail.usask.ca>

On Sun, 2013-07-14 at 17:08 -0600, Chris Friesen wrote:
> > So for memory starting at 0 it should be memory@0
> 
> There are a fair number of dts files in the kernel tree that don't 
> specify an address for the memory node.
> 
> If the kernel accepts it without an address, it seems logical that kexec 
> should as well.

As long as kexec doesn't start being stupid when there are several nodes
and doesn't pick up the "first one in device-tree order" instead of the
one at 0...

I've been hit by that sort of bugs before (though not specifically in
kexec).

> Or maybe the kernel should just implicitly assume an address of zero and 
> export it as such in /proc/device-tree?

I don't want /proc/device-tree to expose something different than what's in
the actual device-tree, that would be the source for endless horrors.

We already are borderline with the occasional renaming we do in the case of
duplicate name+property...

Cheers,
Ben.

  reply	other threads:[~2013-07-14 23:12 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-07-11 20:55 visible memory seems wrong in kexec crash dump kernel Chris Friesen
2013-07-11 20:55 ` Chris Friesen
2013-07-11 21:22 ` Chris Friesen
2013-07-11 21:22   ` Chris Friesen
2013-07-11 22:46   ` Chris Friesen
2013-07-11 22:46     ` Chris Friesen
2013-07-12  1:21   ` Michael Ellerman
2013-07-12  1:21     ` Michael Ellerman
2013-07-12 21:08     ` Chris Friesen
2013-07-12 21:08       ` Chris Friesen
2013-07-12 22:59       ` Chris Friesen
2013-07-12 22:59         ` Chris Friesen
2013-07-13  6:30         ` Chris Friesen
2013-07-13  6:30           ` Chris Friesen
2013-07-14  4:36           ` Michael Ellerman
2013-07-14  4:36             ` Michael Ellerman
2013-07-14  5:26             ` Benjamin Herrenschmidt
2013-07-14  5:26               ` Benjamin Herrenschmidt
2013-07-14 23:08               ` Chris Friesen
2013-07-14 23:08                 ` Chris Friesen
2013-07-14 23:11                 ` Benjamin Herrenschmidt [this message]
2013-07-14 23:11                   ` Benjamin Herrenschmidt
2013-07-29 23:10           ` Scott Wood
2013-07-29 23:10             ` Scott Wood
2013-07-31 16:40             ` Friesen, Christopher
2013-07-31 16:40               ` Friesen, Christopher
2013-07-31 16:50               ` Scott Wood
2013-07-31 16:50                 ` Scott Wood

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