Re: [patch] i386: halt the CPU on serious errors

[Chuck Ebbert]

In-Reply-To: <20060620075015.GB3030@xxxxxxxxxxxxxxxxxxxxxxx>

On Tue, 20 Jun 2006 09:50:15 +0200, Andreas Mohr wrote:

> Thanks for the very fast patch, but:
> 
> >       /* Assume hlt works */
> > -     halt();
> > -     for(;;);
> > +     for (;;)
> > +             halt();
> 
> The comment above seems to hint at this code in arch/i386/kernel/smp.c/
> stop_this_cpu() which does proper hlt checks:
> 
>         if (cpu_data[smp_processor_id()].hlt_works_ok)
>                 for(;;) halt();
>         for (;;);
> 
> So I'm unsure what happens if hlt is not supported properly. Maybe
> there's an invalid opcode exception in a loop then.

  Some ancient CPUs never wake up on interrupt after a halt.  See
include/asm-i386/bugs.h::check_hlt().

-- 
Chuck
 "You can't read a newspaper if you can't read."  --George W. Bush
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