Re: [Patch] kexec: remove KMSG_DUMP_KEXEC (was Re: Query about kdump_msg hook into crash_kexec())

Américo Wang
2011-05-30T07:30:09Z

On Sat, May 28, 2011 at 9:43 AM, Eric W. Biederman
<ebiederm@xmission.com> wrote:
> Andrew Morton <akpm@linux-foundation.org> writes:
>
>> On Thu,  3 Feb 2011 13:53:01 +0900 (JST)
>> KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> wrote:
>>
>>> > > I wrote why this is no good idea by another mail. Please see it.
>>> > > Anyway you have a right to don't use this feature.
>>> > >
>>> >
>>> > But you have not explained that why do you need to hook into crash_kexec()
>>> > and you have also not explained why do you need to send out kdump_msg()
>>> > notification if kdump is configured.
>>> >
>>> > Some detailed explanation here would help.
>>>
>>> Hi,
>>>
>>> I send it you now :)
>>>
>>
>> What happened with this?  kexec-remove-kmsg_dump_kexec.patch has two acks
>> and one unexplained nack :(
>
> As I recall the nack was based on a theoretical use case, and a cleanup
> of kmsg_dump to make it more robust which I don't believe has happened,
> instead of something real.
>
> My feel is that we should remove kmsg_dump and if a real use case comes
> up reconsider it at that time.
>
> I don't think anyone cares too strongly at the moment because the
> features are not expected to be used in conjunction with each other, nor
> even expected to be compiled into the same kernel.  However given that
> they are not used to be used in conjunction with each other a call into
> kmsg_dump from crash_kexec is really just cluttering the code for no
> benefit to anyone.

Seiji once proposed NVRAM which uses kmsg_dump, he wants
to have another way to store panic information when kdump doesn't
work which is _not_ rare in the real world.