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From: Mahesh J Salgaonkar <mahesh@linux.vnet.ibm.com>
To: "Américo Wang" <xiyou.wangcong@gmail.com>
Cc: kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
	linuxppc-dev@ozlabs.org, Anton Blanchard <anton@samba.org>,
	akpm@linux-foundation.org,
	"Eric W. Biederman" <ebiederm@xmission.com>
Subject: Re: [PATCH 1/2] kdump: Allow shrinking of kdump region to be overridden
Date: Tue, 15 Mar 2011 22:22:19 +0530	[thread overview]
Message-ID: <20110315165219.GA22509@in.ibm.com> (raw)
In-Reply-To: <AANLkTi=aDzCaa7_=5XTrnJCzmZPrDy3omXwDarEF8XmH@mail.gmail.com>

On Tue, Mar 15, 2011 at 03:52:38PM +0800, Américo Wang wrote:
> On Tue, Mar 15, 2011 at 2:13 AM, Mahesh J Salgaonkar
> <mahesh@linux.vnet.ibm.com> wrote:
> >
> > During free we do free all of them including RMO region. But since the rtas
> > region is always on top of RMO, crashkernel memory overlaps rtas region and
> > we endup freeing that even, which is causing the crash.
> >
> 
> Okay, but with this patch applied, we will just ignore rtas region, right?
Correct.
> Thus, when I echo 0 to free all the 128M crashkernel memory, the final
> result will be 32M left, which means crash_size will still show 32M.
> This looks odd.
> 
> How about skipping the 32M as a whole? I mean once the region being freed
> has overlap with this rtas region, skip the whole rtas region, and let
> crash_size
> show 0?
The existing code from crash_shrink_memory() function reduces the crash
size to 0 when echo'ed 0. I did test this patchset and verified that
/sys/kernel/kexec_crash_size show 0 value.

Thanks,
-Mahesh.
> 
> _______________________________________________
> kexec mailing list
> kexec@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec

-- 
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>

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

WARNING: multiple messages have this Message-ID (diff)
From: Mahesh J Salgaonkar <mahesh@linux.vnet.ibm.com>
To: "Américo Wang" <xiyou.wangcong@gmail.com>
Cc: kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
	linuxppc-dev@ozlabs.org, Anton Blanchard <anton@samba.org>,
	akpm@linux-foundation.org,
	"Eric W. Biederman" <ebiederm@xmission.com>
Subject: Re: [PATCH 1/2] kdump: Allow shrinking of kdump region to be overridden
Date: Tue, 15 Mar 2011 22:22:19 +0530	[thread overview]
Message-ID: <20110315165219.GA22509@in.ibm.com> (raw)
In-Reply-To: <AANLkTi=aDzCaa7_=5XTrnJCzmZPrDy3omXwDarEF8XmH@mail.gmail.com>

On Tue, Mar 15, 2011 at 03:52:38PM +0800, Américo Wang wrote:
> On Tue, Mar 15, 2011 at 2:13 AM, Mahesh J Salgaonkar
> <mahesh@linux.vnet.ibm.com> wrote:
> >
> > During free we do free all of them including RMO region. But since the rtas
> > region is always on top of RMO, crashkernel memory overlaps rtas region and
> > we endup freeing that even, which is causing the crash.
> >
> 
> Okay, but with this patch applied, we will just ignore rtas region, right?
Correct.
> Thus, when I echo 0 to free all the 128M crashkernel memory, the final
> result will be 32M left, which means crash_size will still show 32M.
> This looks odd.
> 
> How about skipping the 32M as a whole? I mean once the region being freed
> has overlap with this rtas region, skip the whole rtas region, and let
> crash_size
> show 0?
The existing code from crash_shrink_memory() function reduces the crash
size to 0 when echo'ed 0. I did test this patchset and verified that
/sys/kernel/kexec_crash_size show 0 value.

Thanks,
-Mahesh.
> 
> _______________________________________________
> kexec mailing list
> kexec@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec

-- 
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>

WARNING: multiple messages have this Message-ID (diff)
From: Mahesh J Salgaonkar <mahesh@linux.vnet.ibm.com>
To: "Américo Wang" <xiyou.wangcong@gmail.com>
Cc: kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
	linuxppc-dev@ozlabs.org,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	akpm@linux-foundation.org, Anton Blanchard <anton@samba.org>
Subject: Re: [PATCH 1/2] kdump: Allow shrinking of kdump region to be overridden
Date: Tue, 15 Mar 2011 22:22:19 +0530	[thread overview]
Message-ID: <20110315165219.GA22509@in.ibm.com> (raw)
In-Reply-To: <AANLkTi=aDzCaa7_=5XTrnJCzmZPrDy3omXwDarEF8XmH@mail.gmail.com>

On Tue, Mar 15, 2011 at 03:52:38PM +0800, Américo Wang wrote:
> On Tue, Mar 15, 2011 at 2:13 AM, Mahesh J Salgaonkar
> <mahesh@linux.vnet.ibm.com> wrote:
> >
> > During free we do free all of them including RMO region. But since the rtas
> > region is always on top of RMO, crashkernel memory overlaps rtas region and
> > we endup freeing that even, which is causing the crash.
> >
> 
> Okay, but with this patch applied, we will just ignore rtas region, right?
Correct.
> Thus, when I echo 0 to free all the 128M crashkernel memory, the final
> result will be 32M left, which means crash_size will still show 32M.
> This looks odd.
> 
> How about skipping the 32M as a whole? I mean once the region being freed
> has overlap with this rtas region, skip the whole rtas region, and let
> crash_size
> show 0?
The existing code from crash_shrink_memory() function reduces the crash
size to 0 when echo'ed 0. I did test this patchset and verified that
/sys/kernel/kexec_crash_size show 0 value.

Thanks,
-Mahesh.
> 
> _______________________________________________
> kexec mailing list
> kexec@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec

-- 
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>

  reply	other threads:[~2011-03-15 16:52 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
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 [this message]
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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