Re: [PATCH 0/2] mm: introduce MAP_FIXED_SAFE

[Matthew Wilcox]

On Wed, Dec 06, 2017 at 03:51:44PM +1100, Michael Ellerman wrote:
> Cyril Hrubis <chrubis@xxxxxxx> writes:
> 
> > Hi!
> >> > MAP_FIXED_UNIQUE
> >> > MAP_FIXED_ONCE
> >> > MAP_FIXED_FRESH
> >> 
> >> Well, I can open a poll for the best name, but none of those you are
> >> proposing sound much better to me. Yeah, naming sucks...
> >
> > Given that MAP_FIXED replaces the previous mapping MAP_FIXED_NOREPLACE
> > would probably be a best fit.
> 
> Yeah that could work.
> 
> I prefer "no clobber" as I just suggested, because the existing
> MAP_FIXED doesn't politely "replace" a mapping, it destroys the current
> one - which you or another thread may be using - and clobbers it with
> the new one.

It's longer than MAP_FIXED_WEAK :-P

You'd have to be pretty darn strong to clobber an existing mapping.