Re: [PATCH] Allow lockless traversal of notifier lists

[Andi Kleen <ak@suse.de>]

On Mon, Nov 28, 2005 at 09:47:47PM +0530, Dipankar Sarma wrote:
> On Mon, Nov 28, 2005 at 05:05:47PM +0100, Andi Kleen wrote:
> >   *
> >   *	Returns zero on success, or %-ENOENT on failure.
> >   */
> > @@ -175,6 +181,7 @@
> >  
> 
> There should be an smp_read_barrier_depends() here for the first
> dereferencing of the notifier block head, I think.

Why? The one at the top of the block should be enough, shouldn' it?

-Andi


> 
> >  	while(nb)
> >  	{
> > +		smp_read_barrier_depends();
> >  		ret=nb->notifier_call(nb,val,v);
> >  		if(ret&NOTIFY_STOP_MASK)
> >  		{
> 
> Thanks
> Dipankar