Hi,
I am a developer of an yet another crash dump (mkdump).
I'd like to know conditions which cause taking dump fail.
It is helpful to share those informations for dump developers.
I have three major concerns about taking dump.
* interrupt disable
taking dump should be run under interrput disable.
diskdump is aware of that. How about kexec based dump ?
* avoid deadlock
taking dump should not get any locks to avoid deadlock. (?)
I think there are many posibility of deadlock in the kexec
based dump (from crash occur to initiate the new kernel).
(mkdump does not meet neither yet. :-p)
* be sure to get the other CPUs' register value
How are the other CPUs' regsiter value get and how are the
other CPUs stoped ?
(of course the goal of mkdump is to solve these points
although not implemented yet :-)
Any other points to be consider ?
Comments and suggestions are welcome.
Thank you.
--
Itsuro ODA <[email protected]>
Hi,
On Tue, 2004-11-30 at 06:01, Itsuro Oda wrote:
> Hi,
>
> I am a developer of an yet another crash dump (mkdump).
> I'd like to know conditions which cause taking dump fail.
> It is helpful to share those informations for dump developers.
>
> I have three major concerns about taking dump.
> * interrupt disable
> taking dump should be run under interrput disable.
> diskdump is aware of that. How about kexec based dump ?
> * avoid deadlock
> taking dump should not get any locks to avoid deadlock. (?)
> I think there are many posibility of deadlock in the kexec
> based dump (from crash occur to initiate the new kernel).
> (mkdump does not meet neither yet. :-p)
Now kexec based dump is in -mm tree. Could you please have a look at the
code and point out if any problems you see.
> * be sure to get the other CPUs' register value
> How are the other CPUs' regsiter value get and how are the
> other CPUs stoped ?
Kexec based dump does capture the other CPU's register values.
> (of course the goal of mkdump is to solve these points
> although not implemented yet :-)
>
> Any other points to be consider ?
> Comments and suggestions are welcome.
>
> Thank you.
Thanks
Vivek