From: Chris Friesen <cbf123@mail.usask.ca>
To: Michael Ellerman <michael@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
kexec@lists.infradead.org, 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: Fri, 12 Jul 2013 16:59:12 -0600 [thread overview]
Message-ID: <51E08A40.80900@mail.usask.ca> (raw)
In-Reply-To: <51E07056.8040007@mail.usask.ca>
On 07/12/2013 03:08 PM, Chris Friesen wrote:
> I turned on the instrumentation in early_init_dt_scan_memory() and got
> the following when jumping to the capture kernel:
>
> memory scan node memory, reg size 16, data: 0 0 2 0,
> - 0 , 200000000
>
> That 0x200000000 matches the fact that I'm seeing 8GB of memory
> available in the recovery kernel.
>
> If I boot the original kernel with "crashkernel=224M@32M", should I
> expect that only 224MB is marked as "linux,usable-memory" in the
> recovery kernel?
I started looking at the kexec side of things, and I noticed something a
bit odd. In most places dealing with the device tree in kexec it
accepts either "memory" or "memory@" for the memory node name. In
add_usable_mem_property() in arch/ppc64/fs2dt.c it seems to only accept
"memory@".
Is this expected behaviour? It seems to be the same in current git
versions of kexec-tools.
On my system I see "/proc/device-tree/memory".
If I modify add_usable_mem_property() to also accept "/memory" then my
recovery kernel boots up with
physicalMemorySize = 0x10000000
which is 256MB (which is still a bit odd since I specified 224MB for the
crashkernel).
However, it then hits the BUG() call at the end of mark_bootmem() in
mm/bootmem.c.
Chris
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WARNING: multiple messages have this Message-ID (diff)
From: Chris Friesen <cbf123@mail.usask.ca>
To: Michael Ellerman <michael@ellerman.id.au>
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: Fri, 12 Jul 2013 16:59:12 -0600 [thread overview]
Message-ID: <51E08A40.80900@mail.usask.ca> (raw)
In-Reply-To: <51E07056.8040007@mail.usask.ca>
On 07/12/2013 03:08 PM, Chris Friesen wrote:
> I turned on the instrumentation in early_init_dt_scan_memory() and got
> the following when jumping to the capture kernel:
>
> memory scan node memory, reg size 16, data: 0 0 2 0,
> - 0 , 200000000
>
> That 0x200000000 matches the fact that I'm seeing 8GB of memory
> available in the recovery kernel.
>
> If I boot the original kernel with "crashkernel=224M@32M", should I
> expect that only 224MB is marked as "linux,usable-memory" in the
> recovery kernel?
I started looking at the kexec side of things, and I noticed something a
bit odd. In most places dealing with the device tree in kexec it
accepts either "memory" or "memory@" for the memory node name. In
add_usable_mem_property() in arch/ppc64/fs2dt.c it seems to only accept
"memory@".
Is this expected behaviour? It seems to be the same in current git
versions of kexec-tools.
On my system I see "/proc/device-tree/memory".
If I modify add_usable_mem_property() to also accept "/memory" then my
recovery kernel boots up with
physicalMemorySize = 0x10000000
which is 256MB (which is still a bit odd since I specified 224MB for the
crashkernel).
However, it then hits the BUG() call at the end of mark_bootmem() in
mm/bootmem.c.
Chris
next prev parent reply other threads:[~2013-07-12 22:59 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 [this message]
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
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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