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Date: Tue, 27 May 2014 17:31:43 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Christoph Lameter <cl@gentwo.org>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>,
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Subject: Re: [RFC][PATCH 0/5] VM_PINNED
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On Tue, May 27, 2014 at 10:14:10AM -0500, Christoph Lameter wrote:
> On Tue, 27 May 2014, Peter Zijlstra wrote:
> 
> > Well, like with IB, they start out as normal userspace pages, and will
> > be from ZONE_MOVABLE.
> 
> Well we could change that now I think. If the VMA has VM_PINNED set
> pages then do not allocate from ZONE_MOVABLE.

But most allocations sites don't have the vma. We allocate page-cache
pages based on its address_space/mapping, not on whatever vma they're
mapped into.

So I still think the sanest way to do this is by making mm_mpin() do a
mm_populate() and have reclaim skip VM_PINNED pages (so they stay
present), and then migrate the lot out of MOVABLE.