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From:   Bjorn Helgaas <bhelgaas@google.com>
Date:   Wed, 16 Jan 2019 15:44:24 -0600
Message-ID: <CAErSpo6ipXF1P=tHif_ezksD_ka54LYqsc1B11Ddfksm2hp6Jg@mail.gmail.com>
Subject: Re: [PATCH 4/4] dax: "Hotplug" persistent memory for use like normal RAM
To:     Dave Hansen <dave.hansen@intel.com>
Cc:     Dave Hansen <dave.hansen@linux.intel.com>,
        Dave Hansen <dave@sr71.net>,
        Dan Williams <dan.j.williams@intel.com>,
        Dave Jiang <dave.jiang@intel.com>, zwisler@kernel.org,
        vishal.l.verma@intel.com, thomas.lendacky@amd.com,
        Andrew Morton <akpm@linux-foundation.org>, mhocko@suse.com,
        linux-nvdimm@lists.01.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-mm@kvack.org, Huang Ying <ying.huang@intel.com>,
        Wu Fengguang <fengguang.wu@intel.com>,
        Borislav Petkov <bp@suse.de>, baiyaowei@cmss.chinamobile.com,
        Takashi Iwai <tiwai@suse.de>
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On Wed, Jan 16, 2019 at 3:40 PM Dave Hansen <dave.hansen@intel.com> wrote:
> On 1/16/19 1:16 PM, Bjorn Helgaas wrote:
> > On Wed, Jan 16, 2019 at 12:25 PM Dave Hansen
> > <dave.hansen@linux.intel.com> wrote:
> >> From: Dave Hansen <dave.hansen@linux.intel.com>
> >> Currently, a persistent memory region is "owned" by a device driver,
> >> either the "Direct DAX" or "Filesystem DAX" drivers.  These drivers
> >> allow applications to explicitly use persistent memory, generally
> >> by being modified to use special, new libraries.
> >
> > Is there any documentation about exactly what persistent memory is?
> > In Documentation/, I see references to pstore and pmem, which sound
> > sort of similar, but maybe not quite the same?
>
> One instance of persistent memory is nonvolatile DIMMS.  They're
> described in great detail here: Documentation/nvdimm/nvdimm.txt

Thanks!  Some bread crumbs in the changelog to lead there would be great.

Bjorn