Re: [PATCH 3/4] Embed zone_id information within the zonelist->zones pointer

Christoph Lameter
2007-08-10T01:44:07Z

On Fri, 10 Aug 2007, Mel Gorman wrote:

> > > +#if defined(CONFIG_SMP) && INTERNODE_CACHE_SHIFT > ZONES_SHIFT
> >
> > Is this necessary? ZONES_SHIFT is always <= 2 so it will work with
> > any pointer. Why disable this for UP?
> >
>
> Caution in case the number of zones increases. There was no guarantee of
> zone alignment. It's the same reason I have a BUG_ON in the encode
> function so that if we don't catch problems at compile-time, it'll go
> BANG in a nice predictable fashion.

Caution would lead to a BUG_ON but why the #if? Why exclude UP?