From: "Américo Wang" <xiyou.wangcong@gmail.com>
To: Anton Blanchard <anton@samba.org>
Cc: "Mahesh Jagannath Salgaonkar" <mahesh@linux.vnet.ibm.com>,
kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
linuxppc-dev@ozlabs.org,
"Eric W. Biederman" <ebiederm@xmission.com>,
"Américo Wang" <xiyou.wangcong@gmail.com>,
akpm@linux-foundation.org
Subject: Re: [PATCH 1/2] kdump: Allow shrinking of kdump region to be overridden
Date: Wed, 9 Mar 2011 22:21:08 +0800 [thread overview]
Message-ID: <20110309142108.GD16951@cr0.redhat.com> (raw)
In-Reply-To: <20110309234657.264d3080@kryten>
On Wed, Mar 09, 2011 at 11:46:57PM +1100, Anton Blanchard wrote:
>
>Hi,
>
>> The crashkernel region is specified via kernel cmdline, so why
>> not just drop a failure when it overlaps with RMO region?
>> Am I missing something?
>
>Unfortunately a ppc64 kernel requires a chunk of RMO memory. We would
>need the ability to specify multiple crashkernel regions - about 32MB
>in the RMO and the rest can be anywhere. That sounds pretty fragile for
>a user to configure successfully on the cmdline.
>
>Thats why the ppc64 crashkernel region begins mid way through the RMO
>region. It means both kernels get a chunk of RMO and we only have to
>deal with one crashkernel reservation in all the tools and
>documentation.
>
So, when I specify 128M in cmdline, 32M of them are RMO, and the
rest 96M are normal memory? And when I want to free all of them,
actually the 32M RMO will never be freed?
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WARNING: multiple messages have this Message-ID (diff)
From: "Américo Wang" <xiyou.wangcong@gmail.com>
To: Anton Blanchard <anton@samba.org>
Cc: "Mahesh Jagannath Salgaonkar" <mahesh@linux.vnet.ibm.com>,
kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
linuxppc-dev@ozlabs.org,
"Eric W. Biederman" <ebiederm@xmission.com>,
"Américo Wang" <xiyou.wangcong@gmail.com>,
akpm@linux-foundation.org
Subject: Re: [PATCH 1/2] kdump: Allow shrinking of kdump region to be overridden
Date: Wed, 9 Mar 2011 22:21:08 +0800 [thread overview]
Message-ID: <20110309142108.GD16951@cr0.redhat.com> (raw)
In-Reply-To: <20110309234657.264d3080@kryten>
On Wed, Mar 09, 2011 at 11:46:57PM +1100, Anton Blanchard wrote:
>
>Hi,
>
>> The crashkernel region is specified via kernel cmdline, so why
>> not just drop a failure when it overlaps with RMO region?
>> Am I missing something?
>
>Unfortunately a ppc64 kernel requires a chunk of RMO memory. We would
>need the ability to specify multiple crashkernel regions - about 32MB
>in the RMO and the rest can be anywhere. That sounds pretty fragile for
>a user to configure successfully on the cmdline.
>
>Thats why the ppc64 crashkernel region begins mid way through the RMO
>region. It means both kernels get a chunk of RMO and we only have to
>deal with one crashkernel reservation in all the tools and
>documentation.
>
So, when I specify 128M in cmdline, 32M of them are RMO, and the
rest 96M are normal memory? And when I want to free all of them,
actually the 32M RMO will never be freed?
WARNING: multiple messages have this Message-ID (diff)
From: "Américo Wang" <xiyou.wangcong@gmail.com>
To: Anton Blanchard <anton@samba.org>
Cc: "Américo Wang" <xiyou.wangcong@gmail.com>,
"Mahesh Jagannath Salgaonkar" <mahesh@linux.vnet.ibm.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
akpm@linux-foundation.org, kexec@lists.infradead.org,
linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org
Subject: Re: [PATCH 1/2] kdump: Allow shrinking of kdump region to be overridden
Date: Wed, 9 Mar 2011 22:21:08 +0800 [thread overview]
Message-ID: <20110309142108.GD16951@cr0.redhat.com> (raw)
In-Reply-To: <20110309234657.264d3080@kryten>
On Wed, Mar 09, 2011 at 11:46:57PM +1100, Anton Blanchard wrote:
>
>Hi,
>
>> The crashkernel region is specified via kernel cmdline, so why
>> not just drop a failure when it overlaps with RMO region?
>> Am I missing something?
>
>Unfortunately a ppc64 kernel requires a chunk of RMO memory. We would
>need the ability to specify multiple crashkernel regions - about 32MB
>in the RMO and the rest can be anywhere. That sounds pretty fragile for
>a user to configure successfully on the cmdline.
>
>Thats why the ppc64 crashkernel region begins mid way through the RMO
>region. It means both kernels get a chunk of RMO and we only have to
>deal with one crashkernel reservation in all the tools and
>documentation.
>
So, when I specify 128M in cmdline, 32M of them are RMO, and the
rest 96M are normal memory? And when I want to free all of them,
actually the 32M RMO will never be freed?
next prev parent reply other threads:[~2011-03-09 14:21 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-25 0:22 [PATCH 1/2] kdump: Allow shrinking of kdump region to be overridden Anton Blanchard
2010-08-25 0:22 ` Anton Blanchard
2010-08-25 0:22 ` Anton Blanchard
2010-08-25 0:23 ` [PATCH 2/2] powerpc: kdump: Override crash_free_reserved_phys_range to avoid freeing RTAS Anton Blanchard
2010-08-25 0:23 ` Anton Blanchard
2010-08-25 0:23 ` Anton Blanchard
2010-08-25 0:37 ` [PATCH 1/2] kdump: Allow shrinking of kdump region to be overridden Eric W. Biederman
2010-08-25 0:37 ` Eric W. Biederman
2010-08-25 0:37 ` Eric W. Biederman
2011-03-09 6:32 ` Mahesh Jagannath Salgaonkar
2011-03-09 6:32 ` Mahesh Jagannath Salgaonkar
2011-03-09 6:32 ` Mahesh Jagannath Salgaonkar
2011-03-09 12:20 ` Américo Wang
2011-03-09 12:20 ` Américo Wang
2011-03-09 12:20 ` Américo Wang
2011-03-09 12:46 ` Anton Blanchard
2011-03-09 12:46 ` Anton Blanchard
2011-03-09 12:46 ` Anton Blanchard
2011-03-09 14:21 ` Américo Wang [this message]
2011-03-09 14:21 ` Américo Wang
2011-03-09 14:21 ` Américo Wang
2011-03-14 18:13 ` Mahesh J Salgaonkar
2011-03-14 18:13 ` Mahesh J Salgaonkar
2011-03-14 18:13 ` Mahesh J Salgaonkar
2011-03-15 7:52 ` Américo Wang
2011-03-15 7:52 ` Américo Wang
2011-03-15 7:52 ` Américo Wang
2011-03-15 16:52 ` Mahesh J Salgaonkar
2011-03-15 16:52 ` Mahesh J Salgaonkar
2011-03-15 16:52 ` Mahesh J Salgaonkar
2011-03-21 3:10 ` WANG Cong
2011-03-21 3:10 ` WANG Cong
2011-03-24 4:33 ` Benjamin Herrenschmidt
2011-03-24 4:33 ` Benjamin Herrenschmidt
2011-03-24 4:33 ` Benjamin Herrenschmidt
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