Re: [PATCH v2 2/5] mm: introduce external memory hinting API

[Minchan Kim]

On Wed, Jan 22, 2020 at 11:44:24AM +0100, Oleksandr Natalenko wrote:
> Hello.
> 
> On Tue, Jan 21, 2020 at 10:11:13AM -0800, Minchan Kim wrote:
> > > > I also think people don't want to give an KSM hint to non-mergeable area.
> > > 
> > > And how the manager knows which data is mergable?
> > 
> > Oleksandr, could you say your thought why you need address range based
> > API?
> 
> It seems I've overlooked an important piece of this submission: one
> cannot apply the hint to all the anonymous mapping regardless of address
> range. For KSM I'd rather either have a possibility to hint all the
> anonymous mappings, or, as it was suggested previously, be able to iterate
> over existing mappings using some (fd-based?) API.

Thing is how you could identify a certan range is better for KSM than
others from external process?