Re: [PATCH 1/2] i386: mce cleanup part1: functional change

[Joerg Roedel]

On Tue, Oct 09, 2007 at 06:32:30PM +0200, Oleg Verych wrote:
> On Tue, Oct 09, 2007 at 06:06:05PM +0200, Joerg Roedel wrote:
> > > cpu_has() returns int,
> > > but would it be better to have something like
> > > 
> > >   	if (!mce_disabled &&
> > > 	    !(c->x86_capability & (X86_FEATURE_MCA | X86_FEATURE_MCE)) {
> > > 		printk(KERN_INFO "CPU%i: No machine check support available\n",
> > > 			smp_processor_id());
> > 
> > This looks complicated and is harder to read. Its exactly the purpose of the
> > cpu_has() macro to avoid such constructs.
> 
> It is done via test_bit(), which is designed for IO access with all that
> `const volatile' stuff, 2 x unnecessary, can't be optimized here (IMHO).

This code runs only on bootup and once per cpu. I think readable code
is more important here than make it a few cycles faster.

-- 
           |           AMD Saxony Limited Liability Company & Co. KG
 Operating |         Wilschdorfer Landstr. 101, 01109 Dresden, Germany
 System    |                  Register Court Dresden: HRA 4896
 Research  |              General Partner authorized to represent:
 Center    |             AMD Saxony LLC (Wilmington, Delaware, US)
           | General Manager of AMD Saxony LLC: Dr. Hans-R. Deppe, Thomas McCoy


-
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/