Re: [patch 2/2] x86_64: ticket lock spinlock

[Nick Piggin <npiggin@suse.de>]

On Wed, Aug 08, 2007 at 12:26:55PM +0200, Andi Kleen wrote:
> 
> >   *
> >   * (the type definitions are in asm/spinlock_types.h)
> >   */
> >  
> > +#if (NR_CPUS > 256)
> > +#error spinlock supports a maximum of 256 CPUs
> > +#endif
> > +
> >  static inline int __raw_spin_is_locked(raw_spinlock_t *lock)
> >  {
> > -	return *(volatile signed int *)(&(lock)->slock) <= 0;
> > +	int tmp = *(volatile signed int *)(&(lock)->slock);
> 
> Why is slock not volatile signed int in the first place? 

Don't know really. Why does spin_is_locked need it to be volatile?


> > -	int oldval;
> > +	short tmp;
> > +        short oldval;
> 
> Broken white space?

Hmm, I'll fix it.

Thanks,
Nick