From mboxrd@z Thu Jan  1 00:00:00 1970
From: Michal Hocko <mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Subject: Re: [PATCH] mm: introduce MADV_CLR_HUGEPAGE
Date: Wed, 31 May 2017 16:19:40 +0200
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To: Mike Rapoprt <rppt-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
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On Wed 31-05-17 15:39:22, Mike Rapoprt wrote:
> 
> 
> On May 31, 2017 3:08:22 PM GMT+03:00, Michal Hocko <mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> wrote:
[...]
> > From what Mike said a global disable THP for the whole process
> >while the post-copy is in progress is a better solution anyway.
> 
> For the CRIU usecase, disabling THP for a while and re-enabling
> it back will do the trick, provided VMAs flags are not affected,
> like in the patch you've sent.  Moreover, we may even get away with
> ioctl(UFFDIO_COPY) if it's overhead shows to be negligible.  Still,
> I believe that MADV_RESET_HUGEPAGE (or some better named) command has
> the value on its own.

I would prefer if we could go the prctl if possible and add a new
MADV_RESET_HUGEPAGE if there is really a usecase for it.
-- 
Michal Hocko
SUSE Labs