Re: [discuss] Re: [Bug 350] New: i386 context switch very slow compared to 2.4 due to wrmsr (performance)

Peter Finderup Lund
2003-02-14T14:16:18Z

On Fri, 14 Feb 2003, Robert Dewar wrote:

> > > The only way to get from long-mode back to legacy-mode is to reset the
> > > processor. It can be done in software but you will likely lose interrupts.
> >
> > Smartdrv.sys and triple-faults come back, all is forgiven! ;)
>
> I have an idea, perhaps we can make the keyboard controller recognize a special
> command that will reset the processor :-) :-)

What if there was an undocumented instruction otherwise only used for
testing and CPU in-circuit-emulation to load all the internal state of the
CPU from memory? Maybe that would work?

-Peter