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Date: Tue, 9 Oct 2018 14:27:45 +0200
From: Michal Hocko <mhocko@kernel.org>
Subject: Re: [PATCH 1/2] mm: thp:  relax __GFP_THISNODE for MADV_HUGEPAGE
 mappings
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To: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>, Andrea Arcangeli <aarcange@redhat.com>, Andrew Morton <akpm@linux-foundation.org>, Vlastimil Babka <vbabka@suse.cz>, Andrea Argangeli <andrea@kernel.org>, Zi Yan <zi.yan@cs.rutgers.edu>, Stefan Priebe - Profihost AG <s.priebe@profihost.ag>, "Kirill A. Shutemov" <kirill@shutemov.name>, linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>, Stable tree <stable@vger.kernel.org>

[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