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Subject: Re: [PATCHv5 05/19] mm/page_alloc: Handle allocation for encrypted
 memory
References: <20180717112029.42378-1-kirill.shutemov@linux.intel.com>
 <20180717112029.42378-6-kirill.shutemov@linux.intel.com>
 <95ce19cb-332c-44f5-b3a1-6cfebd870127@intel.com>
 <20180719082724.4qvfdp6q4kuhxskn@kshutemo-mobl1>
From: Dave Hansen <dave.hansen@intel.com>
Message-ID: <b0a92a2f-cf14-c976-9fbd-fd9aa4ebcf96@intel.com>
Date: Thu, 19 Jul 2018 07:05:36 -0700
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To: "Kirill A. Shutemov" <kirill@shutemov.name>, Michal Hocko <mhocko@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>, Ingo Molnar <mingo@redhat.com>, x86@kernel.org, Thomas Gleixner <tglx@linutronix.de>, "H. Peter Anvin" <hpa@zytor.com>, Tom Lendacky <thomas.lendacky@amd.com>, Kai Huang <kai.huang@linux.intel.com>, Jacob Pan <jacob.jun.pan@linux.intel.com>, linux-kernel@vger.kernel.org, linux-mm@kvack.org

On 07/19/2018 01:27 AM, Kirill A. Shutemov wrote:
>> What other code might need prep_encrypted_page()?
> 
> Custom pages allocators if these pages can end up in encrypted VMAs.
> 
> It this case compaction creates own pool of pages to be used for
> allocation during page migration.

OK, that makes sense.  It also sounds like some great information to add
near prep_encrypted_page().

Do we have any ability to catch cases like this if we get them wrong, or
will we just silently corrupt data?