Re: [resend] Allow use of MAP_TRYFIXED for better mmap()

[David Laight]

On Thu, Aug 28, 2003 at 07:07:25PM +0200, Jon Bright wrote:
> Alexandre Julliard wrote:
> > With a run-time check you don't have to sacrifice anything, the binary
> > is still portable everywhere, but can also use MAP_TRYFIXED for better
> > performance if it exists in the running kernel.
>
> Except that if you build it on a machine which knows about MAP_TRYFIXED 
> at all, the resulting binary's not likely to run on older machines...

It is exteremely unlikely to run anyway due to changes in other
parts of the ABI.  For instance the dynamic linker in NetBSD 1.5.1 cannot
load programs compiled under NetBSD current (NetBSD current can run programs
compiled under 1.5.1).

It is called 'backwards compatibility'.....

David