Re: [PATCH 1/2] mm: thp: relax __GFP_THISNODE for MADV_HUGEPAGE mappings

From: Michal Hocko
Date: Tue Oct 09 2018 - 08:27:50 EST


[Sorry for being slow in responding but I was mostly offline last few
days]

On Tue 09-10-18 10:48:25, Mel Gorman wrote:
[...]
> This goes back to my point that the MADV_HUGEPAGE hint should not make
> promises about locality and that introducing MADV_LOCAL for specialised
> libraries may be more appropriate with the initial semantic being how it
> treats MADV_HUGEPAGE regions.

I agree with your other points and not going to repeat them. I am not
sure madvise s the best API for the purpose though. We are talking about
memory policy here and there is an existing api for that so I would
_prefer_ to reuse it for this purpose.

Sure we will likely need somethin in the compaction as well but we
should start simple and go forward in smaller steps.
--
Michal Hocko
SUSE Labs