Date: Wed, 7 Dec 2016 10:40:47 -0600 (CST)
From: Christoph Lameter <cl@linux.com>
To: Mel Gorman <mgorman@techsingularity.net>
cc: Andrew Morton <akpm@linux-foundation.org>,
        Michal Hocko <mhocko@suse.com>, Vlastimil Babka <vbabka@suse.cz>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Jesper Dangaard Brouer <brouer@redhat.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>, Linux-MM <linux-mm@kvack.org>,
        Linux-Kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v7
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References: <20161207101228.8128-1-mgorman@techsingularity.net> <alpine.DEB.2.20.1612070849260.8398@east.gentwo.org> <20161207155750.yfsizliaoodks5k4@techsingularity.net>
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On Wed, 7 Dec 2016, Mel Gorman wrote:

> Which is related to the fundamentals of fragmentation control in
> general. At some point there will have to be a revisit to get back to
> the type of reliability that existed in 3.0-era without the massive
> overhead it incurred. As stated before, I agree it's important but
> outside the scope of this patch.

What reliability issues are there? 3.X kernels were better in what
way? Which overhead are we talking about?

Fragmentation has been a problem for a long time and the issue gets worse
as memory sizes increase, the hardware improves and the expectations on
throughput and reliability increase.