David Rientjes <rientjes@xxxxxxxxxx> writes: > On Wed, 1 Jul 2020, Dave Hansen wrote: > >> Even if they don't allocate directly from PMEM, is it OK for such an app >> to get its cold data migrated to PMEM? That's a much more subtle >> question and I suspect the kernel isn't going to have a single answer >> for it. I suspect we'll need a cpuset-level knob to turn auto-demotion >> on or off. >> > > I think the answer is whether the app's cold data can be reclaimed, > otherwise migration to PMEM is likely better in terms of performance. So > any such app today should just be mlocking its cold data if it can't > handle overhead from reclaim? Yes. That's a way to solve the problem. A cpuset-level knob may be more flexible, because you don't need to change the application source code. Best Regards, Huang, Ying
