Re: [RFC PATCH 3/3] mm/map_contig: Add mmap(MAP_CONTIG) support

From: Guy Shattah
Date: Mon Oct 16 2017 - 07:09:20 EST




On 16/10/2017 13:33, Michal Nazarewicz wrote:
On Sun, Oct 15 2017, Guy Shattah wrote:
Why have several driver specific implementation if you can generalize
the idea and implement an already existing POSIX standard?
Why is there a need for contiguous allocation?

This was explained in detail during a talk delivered by me and Christopher Lameter
during Plumbers conference 2017 @ https://linuxplumbersconf.org/2017/ocw/proposals/4669
Please see the slides there.

If generalisation is the issue, then the solution is to define a common
API where user-space can allocate memory *in the context of* a device.
This provides a âgive me memory I can use for this deviceâ request which
is what user space really wants.
Do you suggest to add a whole new common API instead of merely adding a flag to existing one?