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Subject: Re: [PATCH] mm: add ZONE_DEVICE statistics to smaps
To: Dan Williams <dan.j.williams@intel.com>, akpm@linux-foundation.org
References: <147881591739.39198.1358237993213024627.stgit@dwillia2-desk3.amr.corp.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>, linux-nvdimm@ml01.01.org,
        Christoph Hellwig <hch@lst.de>, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org
From: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Date: Fri, 11 Nov 2016 09:42:18 +0530
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On 11/11/2016 03:41 AM, Dan Williams wrote:
> ZONE_DEVICE pages are mapped into a process via the filesystem-dax and
> device-dax mechanisms.  There are also proposals to use ZONE_DEVICE
> pages for other usages outside of dax.  Add statistics to smaps so
> applications can debug that they are obtaining the mappings they expect,
> or otherwise accounting them.

This might also help when we will have ZONE_DEVICE based solution for
HMM based device memory.