kdump regression: /proc/vmcore is 0 after kdump

kdump regression: /proc/vmcore is 0 after kdump

[Luming Yu]

On Tue, Jun 3, 2008 at 2:02 PM, Luming Yu <luming.yu@gmail.com> wrote:
>> I'm trying upstream kdump to get more detailed data for help analysis
>> the scenario..
> Upstream kdump doesn't work! don't know what cause the regression,
> possibly kexec-tools...
> Need investigation here!
>

I tested mainline kernel from 2.6.20 to 2.6.26-rc4 on my tiger4..
whatever I try, /proc/vmcore is always 0 !

Then I managed to get Nan hai's original patch against 2.6.19..
http://marc.info/?l=linux-ia64&m\x116521104831321&w=2
This patch doesn't have zero-vmcore problem.

Given the age of the kdump feature and so many upstream releases since
2.6.20, I'm in doubt why I don't see this kind of bug report on ia64
mailing list before?

PS. Now I can start to capture info for the strace problem with 2.6.19
kernel +Nahai's 2.6.19 kdump patch, hope the problem is still
reproducible.

Thanks,
Luming

Re: kdump regression: /proc/vmcore is 0 after kdump

[Bernhard Walle]

* Luming Yu [2008-06-05 15:58]:
>
> I tested mainline kernel from 2.6.20 to 2.6.26-rc4 on my tiger4..
> whatever I try, /proc/vmcore is always 0 !

Do you use kexec-tools-testing branch (maintained by Simon Horms) in
userspace?


Bernhard

Re: kdump regression: /proc/vmcore is 0 after kdump

[Simon Horman]

On Thu, Jun 05, 2008 at 03:58:40PM +0800, Luming Yu wrote:
> On Tue, Jun 3, 2008 at 2:02 PM, Luming Yu <luming.yu@gmail.com> wrote:
> >> I'm trying upstream kdump to get more detailed data for help analysis
> >> the scenario..
> > Upstream kdump doesn't work! don't know what cause the regression,
> > possibly kexec-tools...
> > Need investigation here!
> >
> 
> I tested mainline kernel from 2.6.20 to 2.6.26-rc4 on my tiger4..
> whatever I try, /proc/vmcore is always 0 !
> 
> Then I managed to get Nan hai's original patch against 2.6.19..
> http://marc.info/?l=linux-ia64&m\x116521104831321&w=2
> This patch doesn't have zero-vmcore problem.
> 
> Given the age of the kdump feature and so many upstream releases since
> 2.6.20, I'm in doubt why I don't see this kind of bug report on ia64
> mailing list before?
> 
> PS. Now I can start to capture info for the strace problem with 2.6.19
> kernel +Nahai's 2.6.19 kdump patch, hope the problem is still
> reproducible.

Which version of kexec-tools are you using?
If you haven't done so already, could you try the latest version, 20080324.

http://www.eu.kernel.org/pub/linux/kernel/people/horms/kexec-tools/

-- 
Horms

Re: kdump regression: /proc/vmcore is 0 after kdump

[Luming Yu]

On Thu, Jun 5, 2008 at 4:16 PM, Simon Horman <horms@verge.net.au> wrote:
> On Thu, Jun 05, 2008 at 03:58:40PM +0800, Luming Yu wrote:
>> On Tue, Jun 3, 2008 at 2:02 PM, Luming Yu <luming.yu@gmail.com> wrote:
>> >> I'm trying upstream kdump to get more detailed data for help analysis
>> >> the scenario..
>> > Upstream kdump doesn't work! don't know what cause the regression,
>> > possibly kexec-tools...
>> > Need investigation here!
>> >
>>
>> I tested mainline kernel from 2.6.20 to 2.6.26-rc4 on my tiger4..
>> whatever I try, /proc/vmcore is always 0 !
>>
>> Then I managed to get Nan hai's original patch against 2.6.19..
>> http://marc.info/?l=linux-ia64&m\x116521104831321&w=2
>> This patch doesn't have zero-vmcore problem.
>>
>> Given the age of the kdump feature and so many upstream releases since
>> 2.6.20, I'm in doubt why I don't see this kind of bug report on ia64
>> mailing list before?
>>
>> PS. Now I can start to capture info for the strace problem with 2.6.19
>> kernel +Nahai's 2.6.19 kdump patch, hope the problem is still
>> reproducible.
>
> Which version of kexec-tools are you using?
> If you haven't done so already, could you try the latest version, 20080324.
>
> http://www.eu.kernel.org/pub/linux/kernel/people/horms/kexec-tools/
>

Yes, this resolves one of my kdump problem.
But there seems to have a regression introduced into upstream probably
starting from 2.6.25.
The last kernel with kdump working on this box is 2.6.24. I don't have
time to start bisection to find out which patch causes that regression
right now.Maybe someone on this list can give me some hint..
Thanks,
Luming

Re: kdump regression: /proc/vmcore is 0 after kdump

[Luming Yu]

On Sat, Jun 14, 2008 at 12:22 AM, Luming Yu <luming.yu@gmail.com> wrote:
> On Thu, Jun 5, 2008 at 4:16 PM, Simon Horman <horms@verge.net.au> wrote:
>> On Thu, Jun 05, 2008 at 03:58:40PM +0800, Luming Yu wrote:
>>> On Tue, Jun 3, 2008 at 2:02 PM, Luming Yu <luming.yu@gmail.com> wrote:
>>> >> I'm trying upstream kdump to get more detailed data for help analysis
>>> >> the scenario..
>>> > Upstream kdump doesn't work! don't know what cause the regression,
>>> > possibly kexec-tools...
>>> > Need investigation here!
>>> >
>>>
>>> I tested mainline kernel from 2.6.20 to 2.6.26-rc4 on my tiger4..
>>> whatever I try, /proc/vmcore is always 0 !
>>>
>>> Then I managed to get Nan hai's original patch against 2.6.19..
>>> http://marc.info/?l=linux-ia64&m\x116521104831321&w=2
>>> This patch doesn't have zero-vmcore problem.
>>>
>>> Given the age of the kdump feature and so many upstream releases since
>>> 2.6.20, I'm in doubt why I don't see this kind of bug report on ia64
>>> mailing list before?
>>>
>>> PS. Now I can start to capture info for the strace problem with 2.6.19
>>> kernel +Nahai's 2.6.19 kdump patch, hope the problem is still
>>> reproducible.
>>
>> Which version of kexec-tools are you using?
>> If you haven't done so already, could you try the latest version, 20080324.
>>
>> http://www.eu.kernel.org/pub/linux/kernel/people/horms/kexec-tools/
>>
>
> Yes, this resolves one of my kdump problem.
> But there seems to have a regression introduced into upstream probably
> starting from 2.6.25.
> The last kernel with kdump working on this box is 2.6.24. I don't have
> time to start bisection to find out which patch causes that regression
> right now.Maybe someone on this list can give me some hint..

My git bisection result indicates the following commit causes the
kdump regression in 2.6.25-rc1:
commit 3c75e23784e6ed5f4841de43d0750fd9b37bafcb
Author: Andrew Patterson <andrew.patterson@hp.com>
Date:   Tue Jan 22 17:18:27 2008 -0700

Re: kdump regression: /proc/vmcore is 0 after kdump

[Bernhard Walle]

* "Luming Yu" <luming.yu@gmail.com> [2008-06-15 17:26]:
>
> My git bisection result indicates the following commit causes the
> kdump regression in 2.6.25-rc1:
> commit 3c75e23784e6ed5f4841de43d0750fd9b37bafcb
> Author: Andrew Patterson <andrew.patterson@hp.com>
> Date:   Tue Jan 22 17:18:27 2008 -0700

Can you verify that reverting that commit indeed fixes kdump at your
site?



Bernhard
-- 
Bernhard Walle, SUSE LINUX Products GmbH, Architecture Development

Re: kdump regression: /proc/vmcore is 0 after kdump

[Luming Yu]

On Sun, Jun 15, 2008 at 5:55 PM, Bernhard Walle <bwalle@suse.de> wrote:
> * "Luming Yu" <luming.yu@gmail.com> [2008-06-15 17:26]:
>>
>> My git bisection result indicates the following commit causes the
>> kdump regression in 2.6.25-rc1:
>> commit 3c75e23784e6ed5f4841de43d0750fd9b37bafcb
>> Author: Andrew Patterson <andrew.patterson@hp.com>
>> Date:   Tue Jan 22 17:18:27 2008 -0700
>
> Can you verify that reverting that commit indeed fixes kdump at your
> site?

I've tested and can confirm reverting this commit resolves crash-boot
hang problem on my Coldfusion box. --Luming