Re: Intel P6 vs P7 system call performance

Matti Aarnio
2002-12-17T17:11:14Z

On Tue, Dec 17, 2002 at 09:07:21AM -0800, Linus Torvalds wrote:
> On Tue, 17 Dec 2002, Hugh Dickins wrote:
> > I thought that last page was intentionally left invalid?
>
> It was. But I thought it made sense to use, as it's the only really
> "special" page.

In couple of occasions I have caught myself from pre-decrementing
a char pointer which "just happened" to be NULL.

Please keep the last page, as well as a few of the first pages as
NULL-pointer poisons.

> But yes, we should decide on this quickly - it's easy to change right now,
> but..
>
> Linus

/Matti Aarnio