Getting the kexec on panic

[Lluís Batlle i Rossell]

On Fri, Sep 07, 2012 at 05:34:33PM +0800, Dave Young wrote:
> On 09/07/2012 06:06 AM, Jerry Snitselaar wrote:
> 
> > On Thu Sep 06 12, Lluís Batlle i Rossell wrote:
> >> Hello,
> >>
> >> while I can load immediately a kernel using kexec, when I set it for panic and
> >> crash with sysrq-c, the computer hangs.
> >>
> >> I'm using the nvidia X driver; can it be that it stops the panic handling from
> >> working? I don't understand why it would work with normal kexec though, if it
> >> were the case.
> >>
> >> Regards,
> >> Lluís.
> > 
> > Hi Lluis,
> > 
> > 
> > What kernel are you using? The commit 722bc6b "x86/mm: Fix the size calculation of mapping tables" which started showing up in 3.5-rc1 causes problems for the crash kernel. You might try this patchset[1] from Jacob Shin and see if it resolves the problem for you if you are experiencing your problem on a 3.5-rc1+ kernel.
> > 
> > [1] https://lkml.org/lkml/2012/8/24/474
> 
> 
> He has updated the v5 patch set as below:
> https://lkml.org/lkml/2012/8/29/227

I was in 3.5.2 when I tried. Ok, I see these are very recent... I may prepare a
build including that.

Thank you!
Lluís.