Re: Console debugging wishlist was: Re: oops pauser.

[Andi Kleen]

On Tuesday 10 January 2006 21:25, Jan Engelhardt wrote:
> An oops is usually a condition you can recover from in some/most/depends 
> cases (e.g. a null deref in a filesystem "only" makes that vfsmount 
> (filesystem at all?) blocked), so if the kernel is waiting for user input 
> on a non-panic condition, this means userspace stops too, which is not 
> too good if the kernel is still 'alive'.
> It's like we are entering kdb although everything is fine enough to go 
> through a proper `init 6`.

-ENOPARSE

> 
> >What would be also cool would be to fix the VGA console to have 
> >a larger scroll back buffer.  The standard kernel boot output 
> >is far larger than the default scrollback, so if you get a hang
> >late you have no way to look back to all the earlier 
> >messages.
> >
> >(it is hard to understand that with 128MB+ graphic cards and 512+MB
> >computers the scroll back must be still so short...) 
> 
> I doubt this scrollback buffer is implemented as part of the video cards. 
> It is rather a kernel invention, and therefore uses standard RAM. But the 
> idea is good, preferably make it a CONFIG_ option.

At least long ago (when I last looked) it was in video RAM. 

> 
> >And fixing sysrq to work after panics would be also nice.
> 
> I am not sure, but would enabling interrupts be enough?

Interrupts are already enabled, but no - it's not.

Thank you for an useful contribution to the thread.

-Andi
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