Re: [Qemu-devel] Re: [PATCH] Reboot CPU on triple fault

[Antoine Kaufmann]

Am Mittwoch, 16. April 2008 11.23:40 schrieb Jamie Lokier:
> Kevin Wolf wrote:
> > > IMHO There's no reason to print a message to stderr. This is all
> > > well defined behavior, and the accepted way of exiting from 286
> > > protected mode.
> >
> > How many users does qemu have who need triple faults to exit from 286
> > Protected Mode?
>
> Not many, only those users running old MS-DOS apps / OSes.
>
> > And how many users does it have who don't use triple
> > faults (yes, it's called a fault, not a PM exiting feature)
>
> Faults don't mean errors.  Think about page faults.

I agree with you, but in that specific case, its definitively an Error if it 
isn't catched earlier.

> > And honestly, a message on stderr really shouldn't hurt those 286 folks.
>
> For old MS-DOS apps / OSes, I have the impression this can happen
> hundreds of times per second.  It's part of task context switching and
> BIOS calls.
If this is really a problem of performance, I would suggest to add a 
commandline switch to disable the error message.
This error message should not be removed imho. Because for those people who 
use it for debugging (I'm one of them), it's really nice. This message makes 
it possible for beginners to see, what went wrong, without further debugging.