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From: Dan Williams <dan.j.williams@intel.com>
Date: Sun, 1 Oct 2017 16:15:06 -0700
Message-ID: <CAPcyv4id1u=DH733rE0AiVDL0q5-53Hs5GRCnEEJNN_Svs0-WQ@mail.gmail.com>
Subject: Re: [PATCH v2 0/4] dax: require 'struct page' and other fixups
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To: Dave Chinner <david@fromorbit.com>
Cc: Christoph Hellwig <hch@lst.de>, Andrew Morton <akpm@linux-foundation.org>, Michal Hocko <mhocko@suse.com>, Jan Kara <jack@suse.cz>, "linux-nvdimm@lists.01.org" <linux-nvdimm@lists.01.org>, Linux MM <linux-mm@kvack.org>, Jeff Moyer <jmoyer@redhat.com>, linux-fsdevel <linux-fsdevel@vger.kernel.org>, Ross Zwisler <ross.zwisler@linux.intel.com>, "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>

On Sun, Oct 1, 2017 at 2:59 PM, Dave Chinner <david@fromorbit.com> wrote:
[..]
> The "capacity tax" had nothing to do with it - the major problem
> with self hosting struct pages was that page locks can be hot and
> contention on them will rapidly burn through write cycles on the
> pmem. That's still a problem, yes?

It was an early concern we had, but it has not born out in practice,
and stopped worrying about it 2 years ago when the ZONE_DEVICE
infrastructure was merged.

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