Re: [RFC] Memory Tiering

[David Hildenbrand]

On 17.10.19 19:07, Verma, Vishal L wrote:
> On Thu, 2019-10-17 at 07:17 -0700, Dave Hansen wrote:
> > On 10/17/19 1:07 AM, David Hildenbrand wrote:
> > > Very interesting topic. I heard similar demand from HPC folks
> > > (especially involving other memory types ("tiers")). There, I think
> > > you often want to let the application manage that. But of course, for
> > > many applications an automatic management might already be
> > > beneficial.
> > >
> > > Am I correct that you are using PMEM in this area along with
> > > ZONE_DEVICE and not by giving PMEM to the buddy (add_memory())?
> >
> > The PMEM starts out as ZONE_DEVICE, but we unbind it from its original
> > driver and bind it to this stub of a "driver": drivers/dax/kmem.c which
> > uses add_memory() on it.
> >
> > There's some nice tooling inside the daxctl component of ndctl to do all
> > the sysfs magic to make this happen.
> Here is more info about the daxctl command in question:
>
> https://pmem.io/ndctl/daxctl-reconfigure-device.html

Thanks, yeah I saw the patches back then (I though they were by Pavel 
but they were actually by you :) ) to add the memory to the buddy (via 
add_memory()).

Will explore some more, thanks!

--

Thanks,

David / dhildenb