Re: [PATCH 0/3] mm/mmap.c: don't unmap the overlapping VMA(s)

From: Michal Hocko
Date: Mon Apr 04 2016 - 03:31:10 EST


On Sat 02-04-16 21:17:31, Piotr Kwapulinski wrote:
> Currently the mmap(MAP_FIXED) discards the overlapping part of the
> existing VMA(s).
> Introduce the new MAP_DONTUNMAP flag which forces the mmap to fail
> with ENOMEM whenever the overlapping occurs and MAP_FIXED is set.
> No existing mapping(s) is discarded.

You forgot to tell us what is the use case for this new flag.
--
Michal Hocko
SUSE Labs