Re: [PATCHv7 02/14] mm: Add support for unaccepted memory

Borislav Petkov
2022-07-25T12:23:29Z

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.