Re: [patch] proposed fix for ptrace() SMP race

[Andrea Arcangeli]

On Fri, Sep 07, 2001 at 02:41:11AM +0100, Alan Cox wrote:
> > +#ifdef CONFIG_SMP
> > +	rmb(); /* read child->has_cpu after child->state */
> > +	while (child->has_cpu);
> 		rep_nop();
> 
> otherwise your PIV will overheat

indeed correct (OTOH it's a so small window [not like a contended
spinlock] that I wonder if it will make a difference in real life ;)

Andrea