Re: [PATCH, RFC, v2] shmat: introduce flag SHM_MAP_HINT

Andi Kleen
2008-10-07T15:10:49Z

On Tue, Oct 07, 2008 at 03:38:44PM +0100, Hugh Dickins wrote:
> On Tue, 7 Oct 2008, Andi Kleen wrote:
> > > I want say that we shouldn't do this check if shmaddr is a search hint.
> > > I'm not sure that check is unneeded if shmadd is the exact address.
> >
> > mmap should fail in this case because it does the same check for
> > MAP_FIXED. Obviously it cannot succeed when there is already something
> > else there.
>
> I'm not really following this, so forgive me if I'm reading you
> out of context, but I think you're wrong on that...

You're right, Hugh, I was confused here. The earlier check
is indeed needed and cannot be dropped. Thanks for the reality check.

-Andi