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Date:   Mon, 25 Jul 2022 14:23:20 +0200
From:   Borislav Petkov <bp@alien8.de>
To:     Dave Hansen <dave.hansen@intel.com>
Cc:     "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Andy Lutomirski <luto@kernel.org>,
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        Andi Kleen <ak@linux.intel.com>,
        Kuppuswamy Sathyanarayanan 
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        Mike Rapoport <rppt@linux.ibm.com>
Subject: Re: [PATCHv7 02/14] mm: Add support for unaccepted memory
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On Fri, Jul 22, 2022 at 12:30:36PM -0700, Dave Hansen wrote:
> Sure does...  *Something* has to manage the cache coherency so that old
> physical aliases of the converted memory don't write back and clobber
> new data.  But, maybe the hardware is doing that now.

Let's hope.

> Yeah, that two-tier system is the way it's happening today from what
> I understand. This whole conversation is about how to handle the >4GB
> memory.

Would it be possible to pre-accept a bunch of mem - think "pre-fault" -
from userspace?

I.e., I'm thinking some huge process is going to start in the VM, VM
userspace goes and causes a chunk of memory to be pre-accepted and then
the process starts and runs more-or-less smoothly as the majority of its
memory has already been "prepared".

Or does that not make any sense from mm perspective?

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette