Re: [v2 RFC PATCH 0/9] Another Approach to Use PMEM as NUMA Node

From: Dave Hansen
Date: Tue Apr 16 2019 - 11:51:05 EST

On 4/16/19 7:39 AM, Michal Hocko wrote:
>> Strict binding also doesn't keep another app from moving the
>> memory.
> I would consider that a bug.

A bug where, though? Certainly not in the kernel.

I'm just saying that if an app has an assumption that strict binding
means that its memory can *NEVER* move, then that assumption is simply
wrong. It's not the guarantee that we provide. In fact, we provide
APIs (migrate_pages() at leaset) that explicitly and intentionally break
that guarantee.

All that our NUMA APIs provide (even the strict ones) is a promise about
where newly-allocated pages will be allocated.