Re: [-mm patch] {rd,wr}msr_on_cpu SMP=n optimization

[Dave Jones]

On Tue, Feb 20, 2007 at 01:07:13AM +0100, Adrian Bunk wrote:
 > On Thu, Feb 15, 2007 at 05:14:08AM -0800, Andrew Morton wrote:
 > >...
 > > Changes since 2.6.20-rc6-mm3:
 > >...
 > > +rdmsr_on_cpu-wrmsr_on_cpu.patch
 > >...
 > >  x86 updates
 > >...
 > 
 > Let's save a few bytes in the CONFIG_SMP=n case.
 > 
 > Signed-off-by: Adrian Bunk <bunk@xxxxxxxxx>
 > 
 > ---
 > 
 > BTW: currently -ENOUSERS

There was a follow-on patch that converted p4-clockmod to use it for one.

 > +#ifdef CONFIG_SMP
 >  void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
 >  void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
 > +#else  /*  CONFIG_SMP  */
 > +static inline void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
 > +{
 > +	rdmsr(msr_no, *l, *h);
 > +}
 > +static inline void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
 > +{
 > +	wrmsr(msr_no, l, h);
 > +}
 > +#endif  /*  CONFIG_SMP  */

BUG_ON(cpu!=smp_processor_id()) maybe?

		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/