Re: [Xen-users] Re: Linux hangs during reboot on Jeremy's git kernel

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

> > a). Bare-metal. Boot pv-ops and shutdown. Does it do it?
> 
>  Yes oddly enough, shutdown is fine, only hangs on reboot.
> 
>  Also I'd like to note I am only using the kernel as a bare-metal kernel, so I have not loaded it as a module in grub with the hypervisor.
> 
> > b). If it does not, try an earlier kernel or a distro supplied one.
> > 
> > If the a) or b) don't work then you have a very unique motherboard
> > and we will need to play a bit with 'reboot=' command line arguments.
> > Look in arch/x86/kernel/reboot.c for details.
> >
> 
>  I have tried using different reboot=X kernel command line arguments, but none of them have correct the rebooting issue. In fact the system hangs the same way in all cases.

<scratches his head> That is most bizzare.
Can you try to get the latest linux kernel and see how it works?

>  
> > Lets assume that a) or b) do work. We want to find out what it does
> > to the machine. You can instrument the code (reboot.c?) and find out
> > which mechanism it uses.
> > 
> 
>  I know that the system reboot fine with the Debian 2.6.26-2-amd64 kernel. Please suggest how one might compare these kernels reboot.c. Shall I simply run the diff utility. I can read C source, but to truly understand it I feel I need to have written the code... With help I believe I can find the mechanism it uses.

Diff would do it. Look for shutdown.c and reboot.c file.
..snip ..
> > What is weird is that your screenshot says "machine reboot" which only
> > shows up when you are running on bare-metal. Was that screen shot taken
> > when pv-ops was running under Xen or bare-metal?
> 
>  As mentioned previous, I was using bare-metal indeed. Should I expect the reboot functionality to work with Jeremy's kernel after using the Xen Hypervisor?

Probably not. The shutdown/reboot code is similar to the upstream
kernel. So if the upstream is not working, then this one wouldn't
either.