Re: [PATCH 1/2] x86: mce init optimization and signedness fixup

From: Dave Jones
Date: Thu Oct 11 2007 - 13:31:18 EST


On Thu, Oct 11, 2007 at 06:50:12PM +0200, Thomas Gleixner wrote:
> On Thu, 11 Oct 2007, Christoph Egger wrote:
> > On Thursday 11 October 2007 16:55:36 Thomas Gleixner wrote:
> > > > > > +
> > > > > > + if (!cpu_has(c, X86_FEATURE_MCA) || !cpu_has(c, X86_FEATURE_MCE)) {
> > > > > > + printk(KERN_INFO "CPU%i: No machine check support available\n",
> > > > > > + smp_processor_id());
> > > > > > + return;
> > > > >
> > > > > This breaks winchip MCE support.
> > > >
> > > > First, what is a winchip? It sounds to be something windows specific. ;)
> > > > Second, can you explain in which way MCE support gets broken, please?
> > >
> > > First, winchip is the code name of Centaurs early x86 cpus.
> > >
> > > Second, those beasts do not have FEATURE_MCA, but they have FEATURE_MCE,
> > > so they support the fatal exception, but not the non fatal check.
> >
> > So when I change the above code snippet to:
> >
> > + if (!cpu_has(c, X86_FEATURE_MCE)) {
> > + printk(KERN_INFO "CPU%i: No machine check support available\n",
> > + smp_processor_id());
> > + return;
> >
> > Would this make the whole patch acceptable then?
>
> Yeah, but then we can clean up the extra checks for _MCE in the various
> cpu type init functions as well.

I question the value of adding the printk.
It's not a failure, there's nothing the user can do about it,
and it adds no real value, just more noise to the dmesg.

Dave

--
http://www.codemonkey.org.uk
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/